AI Trajectory

Trajectory: (Expand/Collapse All)
Seq	Timestamp	Type	Name	Duration
0/0	2026/09/02 19:02	flow	patch-triage	1m Args: null Results: { "EnableConfigs": [ "KVM", "VIRTUALIZATION" ], "FocusSymbols": [ "handle_sthyi", "kvm_s390_handle_b2", "kvm_arch_init_vm", "kvm_s390_vcpu_setup_cmma" ], "KMSANReasoning": "The patch converts page allocations via get_zeroed_page() and free_page() to slab allocations via kzalloc()/kzalloc_obj() and kfree() across s390 KVM code (intercept.c, interrupt.c, priv.c, s390.c). \n\nSince kzalloc/kzalloc_obj zero-initializes the memory identically to get_zeroed_page(), no uninitialized memory usage, conditional branches on uninitialized data, or uninitialized info-leaks to userspace/guest are introduced. Any potential slab-related memory safety issues (e.g. out-of-bounds, use-after-free, or double-free) are monitored by standard KASAN. Thus, a dedicated KMSAN fuzzing session is not required.", "NeedsKMSAN": false, "Reasoning": "The patch changes page-level memory allocations (get_zeroed_page/free_page) to slab allocations (kzalloc/kfree) in KVM on s390 for guest intercept handling (STHYI, STSI), VM initialization (sie_page2), GIB setup, and VCPU CMMA setup. These affect reachable KVM execution paths and memory management on s390, making it worth fuzzing.", "WorthFuzzing": true }
1/1	2026/09/02 19:02	action	read-patch-diff	0m Args: null Results: { "PatchDiff": "commit d6dfce07c89aeb7d6cbdec8c5ab5c85f2699366d\nAuthor: syz-cluster \u003ctriage@syzkaller.com\u003e\nDate: Wed Sep 2 19:02:54 2026 +0000\n\n syz-cluster: applied patch under review\n\ndiff --git a/arch/s390/kvm/s390/intercept.c b/arch/s390/kvm/s390/intercept.c\nindex ca1205dfac8b0..aaf9828d1f44d 100644\n--- a/arch/s390/kvm/s390/intercept.c\n+++ b/arch/s390/kvm/s390/intercept.c\n@@ -11,6 +11,7 @@\n #include \u003clinux/kvm_host.h\u003e\n #include \u003clinux/errno.h\u003e\n #include \u003clinux/pagemap.h\u003e\n+#include \u003clinux/slab.h\u003e\n \n #include \u003casm/asm-offsets.h\u003e\n #include \u003casm/irq.h\u003e\n@@ -438,13 +439,13 @@ int handle_sthyi(struct kvm_vcpu vcpu)\n \tif (!kvm_s390_pv_cpu_is_protected(vcpu) \u0026\u0026 (addr \u0026 ~PAGE_MASK))\n \t\treturn kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);\n \n-\tsctns = (void )get_zeroed_page(GFP_KERNEL_ACCOUNT);\n+\tsctns = kzalloc(PAGE_SIZE, GFP_KERNEL_ACCOUNT);\n \tif (!sctns)\n \t\treturn -ENOMEM;\n \n \tcc = sthyi_fill(sctns, \u0026rc);\n \tif (cc \u003c 0) {\n-\t\tfree_page((unsigned long)sctns);\n+\t\tkfree(sctns);\n \t\treturn cc;\n \t}\n out:\n@@ -454,13 +455,13 @@ int handle_sthyi(struct kvm_vcpu vcpu)\n \t\t} else {\n \t\t\tr = write_guest(vcpu, addr, reg2, sctns, PAGE_SIZE);\n \t\t\tif (r) {\n-\t\t\t\tfree_page((unsigned long)sctns);\n+\t\t\t\tkfree(sctns);\n \t\t\t\treturn kvm_s390_inject_prog_cond(vcpu, r);\n \t\t\t}\n \t\t}\n \t}\n \n-\tfree_page((unsigned long)sctns);\n+\tkfree(sctns);\n \tvcpu-\u003erun-\u003es.regs.gprs[reg2 + 1] = rc;\n \tkvm_s390_set_psw_cc(vcpu, cc);\n \treturn r;\ndiff --git a/arch/s390/kvm/s390/interrupt.c b/arch/s390/kvm/s390/interrupt.c\nindex 0381ae9817035..02065fb8d053e 100644\n--- a/arch/s390/kvm/s390/interrupt.c\n+++ b/arch/s390/kvm/s390/interrupt.c\n@@ -3689,7 +3689,7 @@ void kvm_s390_gib_destroy(void)\n \t}\n \tchsc_sgib(0);\n \tunregister_adapter_interrupt(\u0026gib_alert_irq);\n-\tfree_page((unsigned long)gib);\n+\tkfree(gib);\n \tgib = NULL;\n }\n \n@@ -3703,7 +3703,7 @@ int __init kvm_s390_gib_init(u8 nisc)\n \t\tgoto out;\n \t}\n \n-\tgib = (struct kvm_s390_gib )get_zeroed_page(GFP_KERNEL_ACCOUNT \| GFP_DMA);\n+\tgib = kzalloc(PAGE_SIZE, GFP_KERNEL_ACCOUNT \| GFP_DMA);\n \tif (!gib) {\n \t\trc = -ENOMEM;\n \t\tgoto out;\n@@ -3722,7 +3722,7 @@ int __init kvm_s390_gib_init(u8 nisc)\n \tgib_origin = virt_to_phys(gib);\n \tif (chsc_sgib(gib_origin)) {\n \t\tpr_err(\"Associating the GIB with the AIV facility failed\\n\");\n-\t\tfree_page((unsigned long)gib);\n+\t\tkfree(gib);\n \t\tgib = NULL;\n \t\trc = -EIO;\n \t\tgoto out_unreg_gal;\n@@ -3742,7 +3742,7 @@ int __init kvm_s390_gib_init(u8 nisc)\n out_unreg_gal:\n \tunregister_adapter_interrupt(\u0026gib_alert_irq);\n out_free_gib:\n-\tfree_page((unsigned long)gib);\n+\tkfree(gib);\n \tgib = NULL;\n out:\n \treturn rc;\ndiff --git a/arch/s390/kvm/s390/priv.c b/arch/s390/kvm/s390/priv.c\nindex b3cb2c2c3aa71..856939acf012f 100644\n--- a/arch/s390/kvm/s390/priv.c\n+++ b/arch/s390/kvm/s390/priv.c\n@@ -14,6 +14,7 @@\n #include \u003clinux/mm_types.h\u003e\n #include \u003clinux/pgtable.h\u003e\n #include \u003clinux/io.h\u003e\n+#include \u003clinux/slab.h\u003e\n #include \u003casm/asm-offsets.h\u003e\n #include \u003casm/facility.h\u003e\n #include \u003casm/current.h\u003e\n@@ -869,7 +870,7 @@ static int handle_stsi(struct kvm_vcpu vcpu)\n \tint fc = (vcpu-\u003erun-\u003es.regs.gprs[0] \u0026 0xf0000000) \u003e\u003e 28;\n \tint sel1 = vcpu-\u003erun-\u003es.regs.gprs[0] \u0026 0xff;\n \tint sel2 = vcpu-\u003erun-\u003es.regs.gprs[1] \u0026 0xffff;\n-\tunsigned long mem = 0;\n+\tvoid mem = NULL;\n \tu64 operand2;\n \tint rc = 0;\n \tu8 ar;\n@@ -911,19 +912,19 @@ static int handle_stsi(struct kvm_vcpu vcpu)\n \tswitch (fc) {\n \tcase 1: / same handling for 1 and 2 /\n \tcase 2:\n-\t\tmem = get_zeroed_page(GFP_KERNEL_ACCOUNT);\n+\t\tmem = kzalloc(PAGE_SIZE, GFP_KERNEL_ACCOUNT);\n \t\tif (!mem)\n \t\t\tgoto out_no_data;\n-\t\tif (stsi((void ) mem, fc, sel1, sel2))\n+\t\tif (stsi(mem, fc, sel1, sel2))\n \t\t\tgoto out_no_data;\n \t\tbreak;\n \tcase 3:\n \t\tif (sel1 != 2 \|\| sel2 != 2)\n \t\t\tgoto out_no_data;\n-\t\tmem = get_zeroed_page(GFP_KERNEL_ACCOUNT);\n+\t\tmem = kzalloc(PAGE_SIZE, GFP_KERNEL_ACCOUNT);\n \t\tif (!mem)\n \t\t\tgoto out_no_data;\n-\t\thandle_stsi_3_2_2(vcpu, (void ) mem);\n+\t\thandle_stsi_3_2_2(vcpu, mem);\n \t\tbreak;\n \tcase 15: / fc 15 is fully handled in userspace /\n \t\tinsert_stsi_usr_data(vcpu, operand2, ar, fc, sel1, sel2);\n@@ -931,10 +932,10 @@ static int handle_stsi(struct kvm_vcpu vcpu)\n \t\treturn -EREMOTE;\n \t}\n \tif (kvm_s390_pv_cpu_is_protected(vcpu)) {\n-\t\tmemcpy(sida_addr(vcpu-\u003earch.sie_block), (void )mem, PAGE_SIZE);\n+\t\tmemcpy(sida_addr(vcpu-\u003earch.sie_block), mem, PAGE_SIZE);\n \t\trc = 0;\n \t} else {\n-\t\trc = write_guest(vcpu, operand2, ar, (void )mem, PAGE_SIZE);\n+\t\trc = write_guest(vcpu, operand2, ar, mem, PAGE_SIZE);\n \t}\n \tif (rc) {\n \t\trc = kvm_s390_inject_prog_cond(vcpu, rc);\n@@ -945,14 +946,14 @@ static int handle_stsi(struct kvm_vcpu vcpu)\n \t\trc = -EREMOTE;\n \t}\n \ttrace_kvm_s390_handle_stsi(vcpu, fc, sel1, sel2, operand2);\n-\tfree_page(mem);\n+\tkfree(mem);\n \tkvm_s390_set_psw_cc(vcpu, 0);\n \tvcpu-\u003erun-\u003es.regs.gprs[0] = 0;\n \treturn rc;\n out_no_data:\n \tkvm_s390_set_psw_cc(vcpu, 3);\n out:\n-\tfree_page(mem);\n+\tkfree(mem);\n \treturn rc;\n }\n \ndiff --git a/arch/s390/kvm/s390/s390.c b/arch/s390/kvm/s390/s390.c\nindex b0839e887221e..8ec505060f8c0 100644\n--- a/arch/s390/kvm/s390/s390.c\n+++ b/arch/s390/kvm/s390/s390.c\n@@ -3273,8 +3273,8 @@ int kvm_arch_init_vm(struct kvm kvm, unsigned long type)\n \t\tgoto out_err;\n \n \tBUILD_BUG_ON(sizeof(struct sie_page2) != 4096);\n-\tkvm-\u003earch.sie_page2 =\n-\t (struct sie_page2 ) get_zeroed_page(GFP_KERNEL_ACCOUNT \| GFP_DMA);\n+\tkvm-\u003earch.sie_page2 = kzalloc_obj(kvm-\u003earch.sie_page2,\n+\t\t\t\t\t GFP_KERNEL_ACCOUNT \| GFP_DMA);\n \tif (!kvm-\u003earch.sie_page2)\n \t\tgoto out_err;\n \n@@ -3369,7 +3369,7 @@ int kvm_arch_init_vm(struct kvm kvm, unsigned long type)\n \n \treturn 0;\n out_err:\n-\tfree_page((unsigned long)kvm-\u003earch.sie_page2);\n+\tkfree(kvm-\u003earch.sie_page2);\n \tdebug_unregister(kvm-\u003earch.dbf);\n \tsca_dispose(kvm);\n \tKVM_EVENT(3, \"creation of vm failed: %d\", rc);\n@@ -3427,7 +3427,7 @@ void kvm_arch_destroy_vm(struct kvm kvm)\n \t\tmmu_notifier_unregister(\u0026kvm-\u003earch.pv.mmu_notifier, kvm-\u003emm);\n \n \tdebug_unregister(kvm-\u003earch.dbf);\n-\tfree_page((unsigned long)kvm-\u003earch.sie_page2);\n+\tkfree(kvm-\u003earch.sie_page2);\n \tkvm_s390_destroy_adapters(kvm);\n \tkvm_s390_clear_float_irqs(kvm);\n \tkvm_s390_vsie_destroy(kvm);\n@@ -3657,13 +3657,13 @@ static void kvm_s390_vcpu_crypto_setup(struct kvm_vcpu vcpu)\n void kvm_s390_vcpu_unsetup_cmma(struct kvm_vcpu vcpu)\n {\n \tif (vcpu-\u003earch.sie_block-\u003ecbrlo)\n-\t\tfree_page((unsigned long)phys_to_virt(vcpu-\u003earch.sie_block-\u003ecbrlo));\n+\t\tkfree(phys_to_virt(vcpu-\u003earch.sie_block-\u003ecbrlo));\n \tvcpu-\u003earch.sie_block-\u003ecbrlo = 0;\n }\n \n int kvm_s390_vcpu_setup_cmma(struct kvm_vcpu vcpu)\n {\n-\tvoid cbrlo_page = (void )get_zeroed_page(GFP_KERNEL_ACCOUNT);\n+\tvoid cbrlo_page = kzalloc(PAGE_SIZE, GFP_KERNEL_ACCOUNT);\n \n \tif (!cbrlo_page)\n \t\treturn -ENOMEM;\n" }
2/1	2026/09/02 19:02	agent	patch-evaluator	1m Model: core Args: null Results: { "EnableConfigs": [ "KVM", "VIRTUALIZATION" ], "FocusSymbols": [ "handle_sthyi", "kvm_s390_handle_b2", "kvm_arch_init_vm", "kvm_s390_vcpu_setup_cmma" ], "Reasoning": "The patch changes page-level memory allocations (get_zeroed_page/free_page) to slab allocations (kzalloc/kfree) in KVM on s390 for guest intercept handling (STHYI, STSI), VM initialization (sie_page2), GIB setup, and VCPU CMMA setup. These affect reachable KVM execution paths and memory management on s390, making it worth fuzzing.", "WorthFuzzing": true } Instruction: You are an expert Linux kernel maintainer. Your job is to review a provided patch series and determine if it makes functional changes to the kernel that should be fuzzed. IMPORTANT: The changes have ALREADY been applied and committed as the HEAD commit in your workspace. Do NOT rely on your internal knowledge of the kernel. You must actively use your code access tools to examine the actual source code and confirm any assumptions. Return WorthFuzzing=false if the patch only contains: - Modifications to Documentation/, Kconfig files, or code comments. - Purely decorative changes, such as logging (e.g., pr_err, printk) or tracepoints. - Changes to numeric constants or macros that do not functionally alter execution flow. - Code paths that are impossible to reach in virtualized environments like GCE or QEMU, even when utilizing software-emulated hardware (e.g., usb gadget, mac80211_hwsim). - Code in vendor-specific PCIe switch, SmartNIC, or GPU drivers (e.g., mlxsw, pds_core, qed, ionic, amdgpu) that require physical PCIe hardware cards not emulated in standard QEMU. - Driver .remove, .shutdown, or pci_unregister_driver teardown callbacks (e.g., igb_remove) that are executed only during PCI hot-unplug or sysfs driver unbind operations. If it modifies reachable core kernel logic, drivers, or architectures, use your code search tools to verify the code can be executed, then return WorthFuzzing=true. When returning WorthFuzzing=true, you MUST ALSO: 1. Extract any specific kernel functions that should be heavily fuzzed into FocusSymbols. Avoid listing generic hot-path functions to prevent skewed test distributions. Prefer non-static, non-inlined API entrypoint functions over internal static helper functions (which are inlined by the compiler and do not have distinct symbol addresses). 2. Identify any specific CONFIG_ options required to properly test this new/modified feature. Go and look into the Kconfig files and check for ifdefs around the code, do not make assumptions. Also check "depends on" lines in Kconfig to include any non-standard parent subsystem configs needed for Kbuild to compile the code statically into vmlinux. List them in the EnableConfigs output array, and DO NOT add a 'CONFIG_' prefix (e.g., return "NET_IPV4" instead of "CONFIG_NET_IPV4"). Prefer calling several tools at the same time to save round-trips. Use set-results tool to provide results of the analysis. It must be called exactly once before the final reply. Ignore results of this tool. Prompt: For your convenience, here is the diff of the changes: commit d6dfce07c89aeb7d6cbdec8c5ab5c85f2699366d Author: syz-cluster <triage@syzkaller.com> Date: Wed Sep 2 19:02:54 2026 +0000 syz-cluster: applied patch under review diff --git a/arch/s390/kvm/s390/intercept.c b/arch/s390/kvm/s390/intercept.c index ca1205dfac8b0..aaf9828d1f44d 100644 --- a/arch/s390/kvm/s390/intercept.c +++ b/arch/s390/kvm/s390/intercept.c @@ -11,6 +11,7 @@ #include <linux/kvm_host.h> #include <linux/errno.h> #include <linux/pagemap.h> +#include <linux/slab.h> #include <asm/asm-offsets.h> #include <asm/irq.h> @@ -438,13 +439,13 @@ int handle_sthyi(struct kvm_vcpu vcpu) if (!kvm_s390_pv_cpu_is_protected(vcpu) && (addr & ~PAGE_MASK)) return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION); - sctns = (void )get_zeroed_page(GFP_KERNEL_ACCOUNT); + sctns = kzalloc(PAGE_SIZE, GFP_KERNEL_ACCOUNT); if (!sctns) return -ENOMEM; cc = sthyi_fill(sctns, &rc); if (cc < 0) { - free_page((unsigned long)sctns); + kfree(sctns); return cc; } out: @@ -454,13 +455,13 @@ int handle_sthyi(struct kvm_vcpu vcpu) } else { r = write_guest(vcpu, addr, reg2, sctns, PAGE_SIZE); if (r) { - free_page((unsigned long)sctns); + kfree(sctns); return kvm_s390_inject_prog_cond(vcpu, r); } } } - free_page((unsigned long)sctns); + kfree(sctns); vcpu->run->s.regs.gprs[reg2 + 1] = rc; kvm_s390_set_psw_cc(vcpu, cc); return r; diff --git a/arch/s390/kvm/s390/interrupt.c b/arch/s390/kvm/s390/interrupt.c index 0381ae9817035..02065fb8d053e 100644 --- a/arch/s390/kvm/s390/interrupt.c +++ b/arch/s390/kvm/s390/interrupt.c @@ -3689,7 +3689,7 @@ void kvm_s390_gib_destroy(void) } chsc_sgib(0); unregister_adapter_interrupt(&gib_alert_irq); - free_page((unsigned long)gib); + kfree(gib); gib = NULL; } @@ -3703,7 +3703,7 @@ int __init kvm_s390_gib_init(u8 nisc) goto out; } - gib = (struct kvm_s390_gib )get_zeroed_page(GFP_KERNEL_ACCOUNT \| GFP_DMA); + gib = kzalloc(PAGE_SIZE, GFP_KERNEL_ACCOUNT \| GFP_DMA); if (!gib) { rc = -ENOMEM; goto out; @@ -3722,7 +3722,7 @@ int __init kvm_s390_gib_init(u8 nisc) gib_origin = virt_to_phys(gib); if (chsc_sgib(gib_origin)) { pr_err("Associating the GIB with the AIV facility failed\n"); - free_page((unsigned long)gib); + kfree(gib); gib = NULL; rc = -EIO; goto out_unreg_gal; @@ -3742,7 +3742,7 @@ int __init kvm_s390_gib_init(u8 nisc) out_unreg_gal: unregister_adapter_interrupt(&gib_alert_irq); out_free_gib: - free_page((unsigned long)gib); + kfree(gib); gib = NULL; out: return rc; diff --git a/arch/s390/kvm/s390/priv.c b/arch/s390/kvm/s390/priv.c index b3cb2c2c3aa71..856939acf012f 100644 --- a/arch/s390/kvm/s390/priv.c +++ b/arch/s390/kvm/s390/priv.c @@ -14,6 +14,7 @@ #include <linux/mm_types.h> #include <linux/pgtable.h> #include <linux/io.h> +#include <linux/slab.h> #include <asm/asm-offsets.h> #include <asm/facility.h> #include <asm/current.h> @@ -869,7 +870,7 @@ static int handle_stsi(struct kvm_vcpu vcpu) int fc = (vcpu->run->s.regs.gprs[0] & 0xf0000000) >> 28; int sel1 = vcpu->run->s.regs.gprs[0] & 0xff; int sel2 = vcpu->run->s.regs.gprs[1] & 0xffff; - unsigned long mem = 0; + void mem = NULL; u64 operand2; int rc = 0; u8 ar; @@ -911,19 +912,19 @@ static int handle_stsi(struct kvm_vcpu vcpu) switch (fc) { case 1: / same handling for 1 and 2 / case 2: - mem = get_zeroed_page(GFP_KERNEL_ACCOUNT); + mem = kzalloc(PAGE_SIZE, GFP_KERNEL_ACCOUNT); if (!mem) goto out_no_data; - if (stsi((void ) mem, fc, sel1, sel2)) + if (stsi(mem, fc, sel1, sel2)) goto out_no_data; break; case 3: if (sel1 != 2 \|\| sel2 != 2) goto out_no_data; - mem = get_zeroed_page(GFP_KERNEL_ACCOUNT); + mem = kzalloc(PAGE_SIZE, GFP_KERNEL_ACCOUNT); if (!mem) goto out_no_data; - handle_stsi_3_2_2(vcpu, (void ) mem); + handle_stsi_3_2_2(vcpu, mem); break; case 15: / fc 15 is fully handled in userspace / insert_stsi_usr_data(vcpu, operand2, ar, fc, sel1, sel2); @@ -931,10 +932,10 @@ static int handle_stsi(struct kvm_vcpu vcpu) return -EREMOTE; } if (kvm_s390_pv_cpu_is_protected(vcpu)) { - memcpy(sida_addr(vcpu->arch.sie_block), (void )mem, PAGE_SIZE); + memcpy(sida_addr(vcpu->arch.sie_block), mem, PAGE_SIZE); rc = 0; } else { - rc = write_guest(vcpu, operand2, ar, (void )mem, PAGE_SIZE); + rc = write_guest(vcpu, operand2, ar, mem, PAGE_SIZE); } if (rc) { rc = kvm_s390_inject_prog_cond(vcpu, rc); @@ -945,14 +946,14 @@ static int handle_stsi(struct kvm_vcpu vcpu) rc = -EREMOTE; } trace_kvm_s390_handle_stsi(vcpu, fc, sel1, sel2, operand2); - free_page(mem); + kfree(mem); kvm_s390_set_psw_cc(vcpu, 0); vcpu->run->s.regs.gprs[0] = 0; return rc; out_no_data: kvm_s390_set_psw_cc(vcpu, 3); out: - free_page(mem); + kfree(mem); return rc; } diff --git a/arch/s390/kvm/s390/s390.c b/arch/s390/kvm/s390/s390.c index b0839e887221e..8ec505060f8c0 100644 --- a/arch/s390/kvm/s390/s390.c +++ b/arch/s390/kvm/s390/s390.c @@ -3273,8 +3273,8 @@ int kvm_arch_init_vm(struct kvm kvm, unsigned long type) goto out_err; BUILD_BUG_ON(sizeof(struct sie_page2) != 4096); - kvm->arch.sie_page2 = - (struct sie_page2 ) get_zeroed_page(GFP_KERNEL_ACCOUNT \| GFP_DMA); + kvm->arch.sie_page2 = kzalloc_obj(kvm->arch.sie_page2, + GFP_KERNEL_ACCOUNT \| GFP_DMA); if (!kvm->arch.sie_page2) goto out_err; @@ -3369,7 +3369,7 @@ int kvm_arch_init_vm(struct kvm kvm, unsigned long type) return 0; out_err: - free_page((unsigned long)kvm->arch.sie_page2); + kfree(kvm->arch.sie_page2); debug_unregister(kvm->arch.dbf); sca_dispose(kvm); KVM_EVENT(3, "creation of vm failed: %d", rc); @@ -3427,7 +3427,7 @@ void kvm_arch_destroy_vm(struct kvm kvm) mmu_notifier_unregister(&kvm->arch.pv.mmu_notifier, kvm->mm); debug_unregister(kvm->arch.dbf); - free_page((unsigned long)kvm->arch.sie_page2); + kfree(kvm->arch.sie_page2); kvm_s390_destroy_adapters(kvm); kvm_s390_clear_float_irqs(kvm); kvm_s390_vsie_destroy(kvm); @@ -3657,13 +3657,13 @@ static void kvm_s390_vcpu_crypto_setup(struct kvm_vcpu vcpu) void kvm_s390_vcpu_unsetup_cmma(struct kvm_vcpu vcpu) { if (vcpu->arch.sie_block->cbrlo) - free_page((unsigned long)phys_to_virt(vcpu->arch.sie_block->cbrlo)); + kfree(phys_to_virt(vcpu->arch.sie_block->cbrlo)); vcpu->arch.sie_block->cbrlo = 0; } int kvm_s390_vcpu_setup_cmma(struct kvm_vcpu vcpu) { - void cbrlo_page = (void )get_zeroed_page(GFP_KERNEL_ACCOUNT); + void cbrlo_page = kzalloc(PAGE_SIZE, GFP_KERNEL_ACCOUNT); if (!cbrlo_page) return -ENOMEM;
3/2	2026/09/02 19:02	llm	patch-evaluator	0m Model: gemini-3.7-flash Args: null Results: null Tokens: input: 5145 output: 31 thoughts: 1061 Thoughts: Patch Analysis: s390 KVM Memory Allocation Okay, let's dive into this patch and determine its fuzzing potential. The core of this change seems to involve swapping `get_zeroed_page` and `free_page` with `kzalloc` and `kfree` within the s390 KVM code. Specifically, I'm seeing it in `intercept.c`, `interrupt.c`, `priv.c`, and `s390.c`. Aha, hold on. This is interesting. `get_zeroed_page` is a direct buddy allocator call, grabbing a single page. `kzalloc(PAGE_SIZE, ...)` uses the slab allocator, effectively a `kmalloc-4k` allocation. I'm seeing this with `GFP_KERNEL_ACCOUNT \| GFP_DMA` flags in calls like `kvm_s390_gib_init` and `kvm_arch_init_vm`, which then utilize `virt_to_phys` to get the physical address. And similar logic in `kvm_s390_vcpu_setup_cmma` and `kvm_s390_vcpu_unsetup_cmma`. The slab allocator is indeed page-aligned (4096-byte slab objects). So, the question is why this change? Is this purely refactoring, a cleanup, or does it actually alter behavior? Is it an optimization aimed at slab allocation, or some subtle semantic change? Let me double-check the instruction for deciding if the patch is worth fuzzing. Right, so modifications to documentation, Kconfig, comments, purely decorative changes like logging, constant changes without functional impact, unreachable code in virtualized environments, specific hardware-dependent drivers, and tear-down callbacks are all out. Now, let's consider s390 KVM. Can this be effectively fuzzed, or run within QEMU? Yes, s390 KVM is the KVM hypervisor on the s390x architecture, I know that. But, can it be fuzz tested? QEMU emulates s390x (qemu-system-s390x), but I think KVM inside QEMU on s390x likely needs nested KVM or actual hardware. Syzkaller definitely fuzzes s390x Linux kernels; does it also test s390 KVM if it runs on s390x? Or is it only TCG? The real question is whether this is adding or modifying logic, or if this is just a mechanical replacement of the allocation routines. What was the motivation for this change? I'm going to dig into the git log and maybe search the tree for context to see what the author was thinking.
4/2	2026/09/02 19:03	tool	grepper	0m Args: { "Expression": "kzalloc_obj", "PathPrefix": "arch/s390/" } Results: { "Output": "arch/s390/appldata/appldata_base.c=347=int appldata_register_ops(struct appldata_ops ops)\n--\narch/s390/appldata/appldata_base.c-351-\narch/s390/appldata/appldata_base.c:352:\tops-\u003ectl_table = kzalloc_objs(struct ctl_table, 1);\narch/s390/appldata/appldata_base.c-353-\tif (!ops-\u003ectl_table)\n--\narch/s390/appldata/appldata_mem.c=129=static int __init appldata_mem_init(void)\n--\narch/s390/appldata/appldata_mem.c-132-\narch/s390/appldata/appldata_mem.c:133:\tops.data = kzalloc_obj(struct appldata_mem_data);\narch/s390/appldata/appldata_mem.c-134-\tif (!ops.data)\n--\narch/s390/appldata/appldata_net_sum.c=131=static int __init appldata_net_init(void)\n--\narch/s390/appldata/appldata_net_sum.c-134-\narch/s390/appldata/appldata_net_sum.c:135:\tops.data = kzalloc_obj(struct appldata_net_sum_data);\narch/s390/appldata/appldata_net_sum.c-136-\tif (!ops.data)\n--\narch/s390/hypfs/hypfs_sprp.c=67=static int __hypfs_sprp_ioctl(void __user user_area)\n--\narch/s390/hypfs/hypfs_sprp.c-76-\tdata = (void )get_zeroed_page(GFP_KERNEL);\narch/s390/hypfs/hypfs_sprp.c:77:\tdiag304 = kzalloc_obj(diag304);\narch/s390/hypfs/hypfs_sprp.c-78-\tif (!data \|\| !diag304)\n--\narch/s390/hypfs/inode.c=291=static int hypfs_init_fs_context(struct fs_context fc)\n--\narch/s390/hypfs/inode.c-294-\narch/s390/hypfs/inode.c:295:\tsbi = kzalloc_obj(struct hypfs_sb_info);\narch/s390/hypfs/inode.c-296-\tif (!sbi)\n--\narch/s390/include/asm/idals.h=88=static inline int set_normalized_cda(struct ccw1 ccw, void vaddr)\n--\narch/s390/include/asm/idals.h-96-\tif (nridaws \u003e 0) {\narch/s390/include/asm/idals.h:97:\t\tidal = kzalloc_objs(idal, nridaws, GFP_ATOMIC \| GFP_DMA);\narch/s390/include/asm/idals.h-98-\t\tif (!idal)\n--\narch/s390/kernel/cert_store.c=315=static int invalidate_keyring_keys(struct key keyring)\n--\narch/s390/kernel/cert_store.c-324-\tnum_keys = keyring_payload_len / sizeof(key_serial_t);\narch/s390/kernel/cert_store.c:325:\tkey_array = kzalloc_objs(key_serial_t, num_keys);\narch/s390/kernel/cert_store.c-326-\tif (!key_array)\n--\narch/s390/kernel/debug.c=307=static debug_info_t debug_info_alloc(const char name, int pages_per_area,\n--\narch/s390/kernel/debug.c-316-\t\tgoto fail_malloc_rc;\narch/s390/kernel/debug.c:317:\trc-\u003eactive_entries = kzalloc_objs(int, nr_areas);\narch/s390/kernel/debug.c-318-\tif (!rc-\u003eactive_entries)\narch/s390/kernel/debug.c-319-\t\tgoto fail_malloc_active_entries;\narch/s390/kernel/debug.c:320:\trc-\u003eactive_pages = kzalloc_objs(int, nr_areas);\narch/s390/kernel/debug.c-321-\tif (!rc-\u003eactive_pages)\n--\narch/s390/kernel/guarded_storage.c=22=static int gs_enable(void)\n--\narch/s390/kernel/guarded_storage.c-26-\tif (!current-\u003ethread.gs_cb) {\narch/s390/kernel/guarded_storage.c:27:\t\tgs_cb = kzalloc_obj(gs_cb);\narch/s390/kernel/guarded_storage.c-28-\t\tif (!gs_cb)\n--\narch/s390/kernel/guarded_storage.c=52=static int gs_set_bc_cb(struct gs_cb __user u_gs_cb)\n--\narch/s390/kernel/guarded_storage.c-57-\tif (!gs_cb) {\narch/s390/kernel/guarded_storage.c:58:\t\tgs_cb = kzalloc_obj(gs_cb);\narch/s390/kernel/guarded_storage.c-59-\t\tif (!gs_cb)\n--\narch/s390/kernel/os_info.c=144=static void os_info_old_init(void)\n--\narch/s390/kernel/os_info.c-156-\t\tgoto fail;\narch/s390/kernel/os_info.c:157:\tos_info_old = kzalloc_obj(os_info_old);\narch/s390/kernel/os_info.c-158-\tif (!os_info_old)\n--\narch/s390/kernel/perf_cpum_cf.c=251=static int cpum_cf_alloc_cpu(int cpu, unsigned int num)\n--\narch/s390/kernel/perf_cpum_cf.c-264-\tif (!cpuhw) {\narch/s390/kernel/perf_cpum_cf.c:265:\t\tcpuhw = kzalloc_obj(cpuhw);\narch/s390/kernel/perf_cpum_cf.c-266-\t\tif (cpuhw) {\n--\narch/s390/kernel/perf_cpum_cf.c=1664=static long cfset_ioctl_start(unsigned long arg, struct file file)\n--\narch/s390/kernel/perf_cpum_cf.c-1689-\narch/s390/kernel/perf_cpum_cf.c:1690:\tpreq = kzalloc_obj(preq);\narch/s390/kernel/perf_cpum_cf.c-1691-\tif (!preq)\n--\narch/s390/kernel/perf_cpum_sf.c=1592=static void aux_buffer_setup(struct perf_event event, void *pages,\n--\narch/s390/kernel/perf_cpum_sf.c-1615-\t/ Allocate aux_buffer struct for the event /\narch/s390/kernel/perf_cpum_sf.c:1616:\taux = kzalloc_obj(struct aux_buffer);\narch/s390/kernel/perf_cpum_sf.c-1617-\tif (!aux)\n--\narch/s390/kernel/perf_pai.c=244=static int pai_alloc_cpu(struct perf_event event, int cpu)\n--\narch/s390/kernel/perf_pai.c-261-\t\trc = -ENOMEM;\narch/s390/kernel/perf_pai.c:262:\t\tcpump = kzalloc_obj(cpump);\narch/s390/kernel/perf_pai.c-263-\t\tif (!cpump)\n--\narch/s390/kernel/perf_pai.c=319=static int pai_alloc(struct perf_event event)\n--\narch/s390/kernel/perf_pai.c-323-\narch/s390/kernel/perf_pai.c:324:\tmaskptr = kzalloc_obj(maskptr);\narch/s390/kernel/perf_pai.c-325-\tif (!maskptr)\n--\narch/s390/kernel/perf_pai.c=1077=static struct attribute __init attr_event_init_one(int num,\n--\narch/s390/kernel/perf_pai.c-1082-\narch/s390/kernel/perf_pai.c:1083:\tpa = kzalloc_obj(pa);\narch/s390/kernel/perf_pai.c-1084-\tif (!pa)\n--\narch/s390/kernel/ptrace.c=741=static int s390_gs_cb_set(struct task_struct target,\n--\narch/s390/kernel/ptrace.c-751-\tif (!target-\u003ethread.gs_cb) {\narch/s390/kernel/ptrace.c:752:\t\tdata = kzalloc_obj(data);\narch/s390/kernel/ptrace.c-753-\t\tif (!data)\n--\narch/s390/kernel/ptrace.c=793=static int s390_gs_bc_set(struct task_struct target,\n--\narch/s390/kernel/ptrace.c-802-\tif (!data) {\narch/s390/kernel/ptrace.c:803:\t\tdata = kzalloc_obj(data);\narch/s390/kernel/ptrace.c-804-\t\tif (!data)\n--\narch/s390/kernel/ptrace.c=852=static int s390_runtime_instr_set(struct task_struct target,\n--\narch/s390/kernel/ptrace.c-863-\tif (!target-\u003ethread.ri_cb) {\narch/s390/kernel/ptrace.c:864:\t\tdata = kzalloc_obj(data);\narch/s390/kernel/ptrace.c-865-\t\tif (!data)\n--\narch/s390/kernel/runtime_instr.c=70=SYSCALL_DEFINE2(s390_runtime_instr, int, command, int, signum)\n--\narch/s390/kernel/runtime_instr.c-85-\tif (!current-\u003ethread.ri_cb) {\narch/s390/kernel/runtime_instr.c:86:\t\tcb = kzalloc_obj(cb);\narch/s390/kernel/runtime_instr.c-87-\t\tif (!cb)\n--\narch/s390/kernel/smp.c=1121=int __ref smp_rescan_cpus(bool early)\n--\narch/s390/kernel/smp.c-1125-\narch/s390/kernel/smp.c:1126:\tinfo = kzalloc_obj(info);\narch/s390/kernel/smp.c-1127-\tif (!info)\n--\narch/s390/kernel/vdso.c=129=static struct page * __init vdso_setup_pages(void start, void end)\n--\narch/s390/kernel/vdso.c-134-\narch/s390/kernel/vdso.c:135:\tpagelist = kzalloc_objs(struct page , pages + 1);\narch/s390/kernel/vdso.c-136-\tif (!pagelist)\n--\narch/s390/kvm/gmap/dat.c=31=int kvm_s390_mmu_cache_topup(struct kvm_s390_mmu_cache mc)\n--\narch/s390/kvm/gmap/dat.c-47-\tfor ( ; mc-\u003en_rmaps \u003c KVM_S390_MMU_CACHE_N_RMAPS; mc-\u003en_rmaps++) {\narch/s390/kvm/gmap/dat.c:48:\t\to = kzalloc_obj(struct vsie_rmap, GFP_KERNEL_ACCOUNT);\narch/s390/kvm/gmap/dat.c-49-\t\tif (!o)\n--\narch/s390/kvm/gmap/dat.h=591=static inline struct vsie_rmap kvm_s390_mmu_cache_alloc_rmap(struct kvm_s390_mmu_cache mc)\n--\narch/s390/kvm/gmap/dat.h-594-\t\treturn mc-\u003ermaps[--mc-\u003en_rmaps];\narch/s390/kvm/gmap/dat.h:595:\treturn kzalloc_obj(struct vsie_rmap, GFP_KVM_S390_MMU_CACHE);\narch/s390/kvm/gmap/dat.h-596-}\n--\narch/s390/kvm/gmap/dat.h=939=static inline struct kvm_s390_mmu_cache kvm_s390_new_mmu_cache(void)\n--\narch/s390/kvm/gmap/dat.h-942-\narch/s390/kvm/gmap/dat.h:943:\tmc = kzalloc_obj(mc, GFP_KERNEL_ACCOUNT);\narch/s390/kvm/gmap/dat.h-944-\tif (mc \u0026\u0026 !kvm_s390_mmu_cache_topup(mc))\n--\narch/s390/kvm/gmap/gmap.c=47=struct gmap gmap_new(struct kvm kvm, gfn_t limit)\n--\narch/s390/kvm/gmap/gmap.c-54-\narch/s390/kvm/gmap/gmap.c:55:\tgmap = kzalloc_obj(gmap, GFP_KERNEL_ACCOUNT);\narch/s390/kvm/gmap/gmap.c-56-\tif (!gmap)\n--\narch/s390/kvm/s390/interrupt.c=1749=struct kvm_s390_interrupt_info kvm_s390_get_io_int(struct kvm kvm,\n--\narch/s390/kvm/s390/interrupt.c-1773-gisa_out:\narch/s390/kvm/s390/interrupt.c:1774:\ttmp_inti = kzalloc_obj(inti, GFP_KERNEL_ACCOUNT);\narch/s390/kvm/s390/interrupt.c-1775-\tif (tmp_inti) {\n--\narch/s390/kvm/s390/interrupt.c=2392=static int enqueue_floating_irq(struct kvm_device dev,\n--\narch/s390/kvm/s390/interrupt.c-2404-\twhile (len \u003e= sizeof(struct kvm_s390_irq)) {\narch/s390/kvm/s390/interrupt.c:2405:\t\tinti = kzalloc_obj(inti, GFP_KERNEL_ACCOUNT);\narch/s390/kvm/s390/interrupt.c-2406-\t\tif (!inti)\n--\narch/s390/kvm/s390/interrupt.c=2434=static int register_io_adapter(struct kvm_device dev,\n--\narch/s390/kvm/s390/interrupt.c-2457-\t}\narch/s390/kvm/s390/interrupt.c:2458:\tadapter = kzalloc_obj(adapter, GFP_KERNEL_ACCOUNT);\narch/s390/kvm/s390/interrupt.c-2459-\tif (!adapter) {\n--\narch/s390/kvm/s390/interrupt.c=2512=static int kvm_s390_adapter_map(struct kvm kvm, unsigned int id, __u64 addr)\n--\narch/s390/kvm/s390/interrupt.c-2522-\narch/s390/kvm/s390/interrupt.c:2523:\tmap = kzalloc_obj(map, GFP_KERNEL_ACCOUNT);\narch/s390/kvm/s390/interrupt.c-2524-\tif (!map)\n--\narch/s390/kvm/s390/interrupt.c=2771=static int kvm_s390_inject_airq(struct kvm kvm,\n--\narch/s390/kvm/s390/interrupt.c-2784-\narch/s390/kvm/s390/interrupt.c:2785:\tinti = kzalloc_obj(inti, GFP_KERNEL_ACCOUNT);\narch/s390/kvm/s390/interrupt.c-2786-\tif (!inti)\n--\narch/s390/kvm/s390/interrupt.c=3754=int kvm_arch_set_irq_inatomic(struct kvm_kernel_irq_routing_entry e,\n--\narch/s390/kvm/s390/interrupt.c-3788-\narch/s390/kvm/s390/interrupt.c:3789:\tinti = kzalloc_obj(inti, GFP_ATOMIC);\narch/s390/kvm/s390/interrupt.c-3790-\tif (!inti) {\n--\narch/s390/kvm/s390/pci.c=52=static int zpci_setup_aipb(u8 nisc)\n--\narch/s390/kvm/s390/pci.c-56-\narch/s390/kvm/s390/pci.c:57:\tzpci_aipb = kzalloc_obj(union zpci_sic_iib);\narch/s390/kvm/s390/pci.c-58-\tif (!zpci_aipb)\n--\narch/s390/kvm/s390/pci.c=120=int kvm_s390_pci_aen_init(u8 nisc)\n--\narch/s390/kvm/s390/pci.c-128-\tmutex_lock(\u0026aift-\u003eaift_lock);\narch/s390/kvm/s390/pci.c:129:\taift-\u003ekzdev = kzalloc_objs(struct kvm_zdev , ZPCI_NR_DEVICES);\narch/s390/kvm/s390/pci.c-130-\tif (!aift-\u003ekzdev) {\n--\narch/s390/kvm/s390/pci.c=471=static int kvm_s390_pci_dev_open(struct zpci_dev zdev)\n--\narch/s390/kvm/s390/pci.c-474-\narch/s390/kvm/s390/pci.c:475:\tkzdev = kzalloc_obj(struct kvm_zdev);\narch/s390/kvm/s390/pci.c-476-\tif (!kzdev)\n--\narch/s390/kvm/s390/pci.c=729=int __init kvm_s390_pci_init(void)\n--\narch/s390/kvm/s390/pci.c-736-\narch/s390/kvm/s390/pci.c:737:\taift = kzalloc_obj(struct zpci_aift);\narch/s390/kvm/s390/pci.c-738-\tif (!aift)\n--\narch/s390/kvm/s390/pv.c=476=int kvm_s390_pv_set_aside(struct kvm kvm, u16 rc, u16 rrc)\n--\narch/s390/kvm/s390/pv.c-492-\narch/s390/kvm/s390/pv.c:493:\tpriv = kzalloc_obj(priv);\narch/s390/kvm/s390/pv.c-494-\tif (!priv)\n--\narch/s390/kvm/s390/s390.c=1473=static int kvm_s390_set_processor(struct kvm kvm, struct kvm_device_attr attr)\n--\narch/s390/kvm/s390/s390.c-1483-\t}\narch/s390/kvm/s390/s390.c:1484:\tproc = kzalloc_obj(proc, GFP_KERNEL_ACCOUNT);\narch/s390/kvm/s390/s390.c-1485-\tif (!proc) {\n--\narch/s390/kvm/s390/s390.c=1679=static int kvm_s390_get_processor(struct kvm kvm, struct kvm_device_attr attr)\n--\narch/s390/kvm/s390/s390.c-1683-\narch/s390/kvm/s390/s390.c:1684:\tproc = kzalloc_obj(proc, GFP_KERNEL_ACCOUNT);\narch/s390/kvm/s390/s390.c-1685-\tif (!proc) {\n--\narch/s390/kvm/s390/s390.c=1707=static int kvm_s390_get_machine(struct kvm kvm, struct kvm_device_attr attr)\n--\narch/s390/kvm/s390/s390.c-1711-\narch/s390/kvm/s390/s390.c:1712:\tmach = kzalloc_obj(mach, GFP_KERNEL_ACCOUNT);\narch/s390/kvm/s390/s390.c-1713-\tif (!mach) {\n--\narch/s390/kvm/s390/s390.c=2900=int kvm_arch_vm_ioctl(struct file filp, unsigned int ioctl, unsigned long arg)\n--\narch/s390/kvm/s390/s390.c-2917-\t\t\tbreak;\narch/s390/kvm/s390/s390.c:2918:\t\tinti = kzalloc_obj(inti, GFP_KERNEL_ACCOUNT);\narch/s390/kvm/s390/s390.c-2919-\t\tif (!inti)\n--\narch/s390/kvm/s390/s390.c=3240=int kvm_arch_init_vm(struct kvm kvm, unsigned long type)\n--\narch/s390/kvm/s390/s390.c-3275-\tBUILD_BUG_ON(sizeof(struct sie_page2) != 4096);\narch/s390/kvm/s390/s390.c:3276:\tkvm-\u003earch.sie_page2 = kzalloc_obj(kvm-\u003earch.sie_page2,\narch/s390/kvm/s390/s390.c-3277-\t\t\t\t\t GFP_KERNEL_ACCOUNT \| GFP_DMA);\n--\narch/s390/kvm/s390/s390.c=4451=static void __kvm_inject_pfault_token(struct kvm_vcpu vcpu, bool start_token,\n--\narch/s390/kvm/s390/s390.c-4463-\t} else {\narch/s390/kvm/s390/s390.c:4464:\t\tinti_mem = kzalloc_obj(inti_mem, GFP_KERNEL_ACCOUNT);\narch/s390/kvm/s390/s390.c-4465-\t\tif (WARN_ON_ONCE(!inti_mem))\n--\narch/s390/mm/extmem.c=297=__segment_load (char name, int do_nonshared, unsigned long addr, unsigned long end)\n--\narch/s390/mm/extmem.c-319-\narch/s390/mm/extmem.c:320:\tseg-\u003eres = kzalloc_obj(struct resource);\narch/s390/mm/extmem.c-321-\tif (seg-\u003eres == NULL) {\n--\narch/s390/net/bpf_jit_comp.c=2386=struct bpf_prog bpf_int_jit_compile(struct bpf_verifier_env env, struct bpf_prog fp)\n--\narch/s390/net/bpf_jit_comp.c-2398-\tif (!jit_data) {\narch/s390/net/bpf_jit_comp.c:2399:\t\tjit_data = kzalloc_obj(jit_data);\narch/s390/net/bpf_jit_comp.c-2400-\t\tif (!jit_data)\n--\narch/s390/pci/pci.c=522=static struct resource __alloc_res(struct zpci_dev zdev, unsigned long start,\n--\narch/s390/pci/pci.c-526-\narch/s390/pci/pci.c:527:\tr = kzalloc_obj(r);\narch/s390/pci/pci.c-528-\tif (!r)\n--\narch/s390/pci/pci.c=823=struct zpci_dev zpci_create_device(u32 fid, u32 fh, enum zpci_state state)\n--\narch/s390/pci/pci.c-827-\narch/s390/pci/pci.c:828:\tzdev = kzalloc_obj(zdev);\narch/s390/pci/pci.c-829-\tif (!zdev)\n--\narch/s390/pci/pci.c=1066=static int zpci_mem_init(void)\n--\narch/s390/pci/pci.c-1077-\narch/s390/pci/pci.c:1078:\tzpci_iomap_start = kzalloc_objs(zpci_iomap_start, ZPCI_IOMAP_ENTRIES);\narch/s390/pci/pci.c-1079-\tif (!zpci_iomap_start)\n--\narch/s390/pci/pci_bus.c=314=static struct zpci_bus zpci_bus_alloc(int topo, bool topo_is_tid)\n--\narch/s390/pci/pci_bus.c-317-\narch/s390/pci/pci_bus.c:318:\tzbus = kzalloc_obj(zbus);\narch/s390/pci/pci_bus.c-319-\tif (!zbus)\n--\narch/s390/pci/pci_irq.c=552=static int __init zpci_directed_irq_init(void)\n--\narch/s390/pci/pci_irq.c-565-\narch/s390/pci/pci_irq.c:566:\tzpci_ibv = kzalloc_objs(zpci_ibv, num_possible_cpus());\narch/s390/pci/pci_irq.c-567-\tif (!zpci_ibv)\n--\narch/s390/pci/pci_irq.c=590=static int __init zpci_floating_irq_init(void)\narch/s390/pci/pci_irq.c-591-{\narch/s390/pci/pci_irq.c:592:\tzpci_ibv = kzalloc_objs(zpci_ibv, ZPCI_NR_DEVICES);\narch/s390/pci/pci_irq.c-593-\tif (!zpci_ibv)\n" }
5/2	2026/09/02 19:03	llm	patch-evaluator	0m Model: gemini-3.7-flash Args: null Results: null Tokens: input: 14506 output: 29 thoughts: 629 Thoughts: Patch Review: KVM Memory Allocation on s390 Okay, let's dive back into this patch. I need to make sure I haven't missed anything, so I'm going to carefully step through each change. It looks like we're addressing memory allocation and deallocation within the s390 KVM code. This is critical; even a small leak or misuse can destabilize the entire system, especially in a virtualization context. The first block, `arch/s390/kvm/s390/intercept.c` specifically the `handle_sthyi` function, is where the initial change comes in; `get_zeroed_page` is being replaced by `kzalloc` for `sctns`. This is a pretty straightforward conversion: `kzalloc` combines the `get_zeroed_page` with a `memset(0)` to initialize the memory. Correspondingly, `free_page` is replaced with `kfree`. That's good; it's cleaner and functionally equivalent. The same pattern holds for `arch/s390/kvm/s390/interrupt.c`, `kvm_s390_gib_destroy` and `kvm_s390_gib_init`, and also `arch/s390/kvm/s390/priv.c` and `handle_stsi`, with the same changes between `get_zeroed_page` and `kzalloc` and the appropriate `free_page` calls being changed to `kfree`. The fourth chunk, in `arch/s390/kvm/s390/s390.c`, is slightly more involved. Here, within `kvm_arch_init_vm`, `kvm_arch_destroy_vm`, `kvm_s390_vcpu_setup_cmma`, and `kvm_s390_vcpu_unsetup_cmma`, we see the same transition from `get_zeroed_page` to `kzalloc`, but with the addition of `*` for the `kvm->arch.sie_page2` pointer. It looks like it could be calling a helper. And for the other case in this file, we have the same situation as before with the replacement of `free_page` with `kfree` when dealing with the physical memory. These are all important functions; any memory-related issues in `kvm_arch_init_vm` or `kvm_arch_destroy_vm` are likely to cause some big problems when launching or shutting down VMs. I need to keep an eye on how these function calls are structured. This seems like a pretty standard and sensible change. These functions are often where subtle memory management issues can creep in, so this kind of modernization is usually a good thing. The use of `kzalloc` is generally preferred now because it is cleaner, handles the zeroing internally, and is more consistent. I assume there isn't a significant performance difference here. Before giving it a stamp of approval, I should check the Kconfig options to verify the change doesn't introduce some unexpected dependency or change the configuration. I'll need to double check the Kconfig for any subtle effects. I'll search for 'KVM' within the `arch/s390` directory just to make sure I am not missing any dependencies or other relevant Kconfig options to get a full picture.
6/2	2026/09/02 19:03	tool	grepper	0m Args: { "Expression": "KVM", "PathPrefix": "arch/s390/" } Results: { "Output": "\nFull output is too long, showing 500 out of 3872 lines.\nUse more precise expression if possible.\n\narch/s390/Kbuild=3=obj-y\t\t\t\t+= mm/\narch/s390/Kbuild:4:obj-$(CONFIG_KVM)\t\t+= kvm/\narch/s390/Kbuild-5-obj-y\t\t\t\t+= crypto/\n--\narch/s390/Kconfig=846=config VFIO_AP\n--\narch/s390/Kconfig-848-\tprompt \"VFIO support for AP devices\"\narch/s390/Kconfig:849:\tdepends on KVM\narch/s390/Kconfig-850-\tdepends on VFIO\n--\narch/s390/Kconfig=990=config S390_GUEST\n--\narch/s390/Kconfig-1000-\t Select this option if you want to run the kernel as a guest under\narch/s390/Kconfig:1001:\t the KVM hypervisor.\narch/s390/Kconfig-1002-\n--\narch/s390/boot/ipl_parm.c=249=void parse_boot_command_line(void)\n--\narch/s390/boot/ipl_parm.c-302-\narch/s390/boot/ipl_parm.c:303:#if IS_ENABLED(CONFIG_KVM)\narch/s390/boot/ipl_parm.c-304-\t\tif (!strcmp(param, \"prot_virt\")) {\n--\narch/s390/boot/startup.c=52=static void detect_machine_type(void)\n--\narch/s390/boot/startup.c-65-\tif (!memcmp(vmms-\u003evm[0].cpi, \"\\xd2\\xe5\\xd4\", 3))\narch/s390/boot/startup.c:66:\t\tset_machine_feature(MFEATURE_KVM);\narch/s390/boot/startup.c-67-\telse if (!memcmp(vmms-\u003evm[0].cpi, \"\\xa9\\x61\\xe5\\xd4\", 4))\n--\narch/s390/boot/uv.c=15=void uv_query_info(void)\n--\narch/s390/boot/uv.c-28-\narch/s390/boot/uv.c:29:\tif (IS_ENABLED(CONFIG_KVM)) {\narch/s390/boot/uv.c-30-\t\tmemcpy(uv_info.inst_calls_list, uvcb.inst_calls_list, sizeof(uv_info.inst_calls_list));\n--\narch/s390/configs/debug_defconfig=67=CONFIG_S390_HYPFS_FS=y\narch/s390/configs/debug_defconfig:68:CONFIG_KVM=m\narch/s390/configs/debug_defconfig:69:CONFIG_KVM_S390_UCONTROL=y\narch/s390/configs/debug_defconfig-70-CONFIG_S390_UNWIND_SELFTEST=m\n--\narch/s390/configs/defconfig=65=CONFIG_S390_HYPFS_FS=y\narch/s390/configs/defconfig:66:CONFIG_KVM=m\narch/s390/configs/defconfig-67-CONFIG_S390_UNWIND_SELFTEST=m\n--\narch/s390/include/asm/entry-common.h=54=static __always_inline bool arch_in_rcu_eqs(void)\narch/s390/include/asm/entry-common.h-55-{\narch/s390/include/asm/entry-common.h:56:\tif (IS_ENABLED(CONFIG_KVM))\narch/s390/include/asm/entry-common.h-57-\t\treturn current-\u003eflags \u0026 PF_VCPU;\n--\narch/s390/include/asm/gmap_helpers.h-2-/\narch/s390/include/asm/gmap_helpers.h:3: Helper functions for KVM guest address space mapping code\narch/s390/include/asm/gmap_helpers.h-4- \n--\narch/s390/include/asm/kvm_host.h-2-\narch/s390/include/asm/kvm_host.h:3:#ifndef ASM_KVM_HOST_H\narch/s390/include/asm/kvm_host.h:4:#define ASM_KVM_HOST_H\narch/s390/include/asm/kvm_host.h-5-\n--\narch/s390/include/asm/kvm_host.h-64-\narch/s390/include/asm/kvm_host.h:65:#endif / ASM_KVM_HOST_H /\n--\narch/s390/include/asm/kvm_host_s390.h-10-\narch/s390/include/asm/kvm_host_s390.h:11:#ifndef ASM_KVM_HOST_S390_H\narch/s390/include/asm/kvm_host_s390.h:12:#define ASM_KVM_HOST_S390_H\narch/s390/include/asm/kvm_host_s390.h-13-\n--\narch/s390/include/asm/kvm_host_s390.h-29-\narch/s390/include/asm/kvm_host_s390.h:30:#define KVM_HAVE_MMU_RWLOCK\narch/s390/include/asm/kvm_host_s390.h:31:#define KVM_MAX_VCPUS 255\narch/s390/include/asm/kvm_host_s390.h-32-\narch/s390/include/asm/kvm_host_s390.h:33:#define KVM_INTERNAL_MEM_SLOTS 1\narch/s390/include/asm/kvm_host_s390.h-34-\narch/s390/include/asm/kvm_host_s390.h:35:#define KVM_S390_MANAGES_S390_GUEST 1\narch/s390/include/asm/kvm_host_s390.h-36-\n--\narch/s390/include/asm/kvm_host_s390.h-41- /\narch/s390/include/asm/kvm_host_s390.h:42:#define KVM_NR_IRQCHIPS 1\narch/s390/include/asm/kvm_host_s390.h:43:#define KVM_IRQCHIP_NUM_PINS 1\narch/s390/include/asm/kvm_host_s390.h:44:#define KVM_HALT_POLL_NS_DEFAULT 50000\narch/s390/include/asm/kvm_host_s390.h-45-\narch/s390/include/asm/kvm_host_s390.h-46-/* s390-specific vcpu-\u003erequests bit members /\narch/s390/include/asm/kvm_host_s390.h:47:#define KVM_REQ_ENABLE_IBS\tKVM_ARCH_REQ(0)\narch/s390/include/asm/kvm_host_s390.h:48:#define KVM_REQ_DISABLE_IBS\tKVM_ARCH_REQ(1)\narch/s390/include/asm/kvm_host_s390.h:49:#define KVM_REQ_ICPT_OPEREXC\tKVM_ARCH_REQ(2)\narch/s390/include/asm/kvm_host_s390.h:50:#define KVM_REQ_START_MIGRATION KVM_ARCH_REQ(3)\narch/s390/include/asm/kvm_host_s390.h:51:#define KVM_REQ_STOP_MIGRATION KVM_ARCH_REQ(4)\narch/s390/include/asm/kvm_host_s390.h:52:#define KVM_REQ_VSIE_RESTART\tKVM_ARCH_REQ(5)\narch/s390/include/asm/kvm_host_s390.h:53:#define KVM_REQ_REFRESH_GUEST_PREFIX\t\\\narch/s390/include/asm/kvm_host_s390.h:54:\tKVM_ARCH_REQ_FLAGS(6, KVM_REQUEST_WAIT \| KVM_REQUEST_NO_WAKEUP)\narch/s390/include/asm/kvm_host_s390.h-55-\n--\narch/s390/include/asm/kvm_host_s390.h=156=enum irq_types {\n--\narch/s390/include/asm/kvm_host_s390.h-190- /\narch/s390/include/asm/kvm_host_s390.h:191:#define KVM_S390_MAX_VIRTIO_IRQS 87381\narch/s390/include/asm/kvm_host_s390.h-192-\n--\narch/s390/include/asm/kvm_host_s390.h=268=struct kvm_s390_local_interrupt {\narch/s390/include/asm/kvm_host_s390.h-269-\tspinlock_t lock;\narch/s390/include/asm/kvm_host_s390.h:270:\tDECLARE_BITMAP(sigp_emerg_pending, KVM_MAX_VCPUS);\narch/s390/include/asm/kvm_host_s390.h-271-\tstruct kvm_s390_irq_payload irq;\n--\narch/s390/include/asm/kvm_host_s390.h-294-\narch/s390/include/asm/kvm_host_s390.h:295:#define KVM_S390_AIS_MODE_ALL 0\narch/s390/include/asm/kvm_host_s390.h:296:#define KVM_S390_AIS_MODE_SINGLE 1\narch/s390/include/asm/kvm_host_s390.h-297-\n--\narch/s390/include/asm/kvm_host_s390.h=319=struct kvm_hw_bp_info_arch {\n--\narch/s390/include/asm/kvm_host_s390.h-325- * Only the upper 16 bits of kvm_guest_debug-\u003econtrol are arch specific.\narch/s390/include/asm/kvm_host_s390.h:326: * Further KVM_GUESTDBG flags which an be used from userspace can be found in\narch/s390/include/asm/kvm_host_s390.h-327- * arch/s390/include/uapi/asm/kvm.h\narch/s390/include/asm/kvm_host_s390.h-328- /\narch/s390/include/asm/kvm_host_s390.h:329:#define KVM_GUESTDBG_EXIT_PENDING 0x10000000\narch/s390/include/asm/kvm_host_s390.h-330-\narch/s390/include/asm/kvm_host_s390.h-331-#define guestdbg_enabled(vcpu) \\\narch/s390/include/asm/kvm_host_s390.h:332:\t\t(vcpu-\u003eguest_debug \u0026 KVM_GUESTDBG_ENABLE)\narch/s390/include/asm/kvm_host_s390.h-333-#define guestdbg_sstep_enabled(vcpu) \\\narch/s390/include/asm/kvm_host_s390.h:334:\t\t(vcpu-\u003eguest_debug \u0026 KVM_GUESTDBG_SINGLESTEP)\narch/s390/include/asm/kvm_host_s390.h-335-#define guestdbg_hw_bp_enabled(vcpu) \\\narch/s390/include/asm/kvm_host_s390.h:336:\t\t(vcpu-\u003eguest_debug \u0026 KVM_GUESTDBG_USE_HW_BP)\narch/s390/include/asm/kvm_host_s390.h-337-#define guestdbg_exit_pending(vcpu) (guestdbg_enabled(vcpu) \u0026\u0026 \\\narch/s390/include/asm/kvm_host_s390.h:338:\t\t(vcpu-\u003eguest_debug \u0026 KVM_GUESTDBG_EXIT_PENDING))\narch/s390/include/asm/kvm_host_s390.h-339-\narch/s390/include/asm/kvm_host_s390.h:340:#define KVM_GUESTDBG_VALID_MASK \\\narch/s390/include/asm/kvm_host_s390.h:341:\t\t(KVM_GUESTDBG_ENABLE \| KVM_GUESTDBG_SINGLESTEP \|\\\narch/s390/include/asm/kvm_host_s390.h:342:\t\tKVM_GUESTDBG_USE_HW_BP \| KVM_GUESTDBG_EXIT_PENDING)\narch/s390/include/asm/kvm_host_s390.h-343-\n--\narch/s390/include/asm/kvm_host_s390.h=576=struct kvm_s390_vsie {\n--\narch/s390/include/asm/kvm_host_s390.h-580-\tint next;\narch/s390/include/asm/kvm_host_s390.h:581:\tstruct vsie_page pages[KVM_MAX_VCPUS];\narch/s390/include/asm/kvm_host_s390.h-582-};\n--\narch/s390/include/asm/kvm_host_s390.h=590=struct kvm_s390_gisa_interrupt {\n--\narch/s390/include/asm/kvm_host_s390.h-594-\tu64 expires;\narch/s390/include/asm/kvm_host_s390.h:595:\tDECLARE_BITMAP(kicked_mask, KVM_MAX_VCPUS);\narch/s390/include/asm/kvm_host_s390.h-596-};\n--\narch/s390/include/asm/kvm_host_s390.h=613=struct kvm_arch {\n--\narch/s390/include/asm/kvm_host_s390.h-645-\t/* subset of available cpu features enabled by user space /\narch/s390/include/asm/kvm_host_s390.h:646:\tDECLARE_BITMAP(cpu_feat, KVM_S390_VM_CPU_FEAT_NR_BITS);\narch/s390/include/asm/kvm_host_s390.h-647-\t/ indexed by vcpu_idx /\narch/s390/include/asm/kvm_host_s390.h:648:\tDECLARE_BITMAP(idle_mask, KVM_MAX_VCPUS);\narch/s390/include/asm/kvm_host_s390.h-649-\tstruct kvm_s390_gisa_interrupt gisa_int;\n--\narch/s390/include/asm/kvm_host_s390.h-655-\narch/s390/include/asm/kvm_host_s390.h:656:#define KVM_HVA_ERR_BAD\t\t(-1UL)\narch/s390/include/asm/kvm_host_s390.h:657:#define KVM_HVA_ERR_RO_BAD\t(-2UL)\narch/s390/include/asm/kvm_host_s390.h-658-\n--\narch/s390/include/asm/kvm_host_s390.h=717=static inline void kvm_arch_vcpu_unblocking(struct kvm_vcpu vcpu) {}\narch/s390/include/asm/kvm_host_s390.h-718-\narch/s390/include/asm/kvm_host_s390.h:719:#define __KVM_HAVE_ARCH_VM_FREE\narch/s390/include/asm/kvm_host_s390.h-720-void kvm_arch_free_vm(struct kvm kvm);\n--\narch/s390/include/asm/kvm_host_s390.h=727=extern struct zpci_kvm_hook zpci_kvm_hook;\narch/s390/include/asm/kvm_host_s390.h-728-\narch/s390/include/asm/kvm_host_s390.h:729:#endif / ASM_KVM_HOST_S390_H /\n--\narch/s390/include/asm/kvm_host_s390_types.h-2-\narch/s390/include/asm/kvm_host_s390_types.h:3:#ifndef _ASM_KVM_HOST_S390_TYPES_H\narch/s390/include/asm/kvm_host_s390_types.h:4:#define _ASM_KVM_HOST_S390_TYPES_H\narch/s390/include/asm/kvm_host_s390_types.h-5-\n--\narch/s390/include/asm/kvm_host_s390_types.h-8-\narch/s390/include/asm/kvm_host_s390_types.h:9:#define KVM_S390_BSCA_CPU_SLOTS 64\narch/s390/include/asm/kvm_host_s390_types.h:10:#define KVM_S390_ESCA_CPU_SLOTS 248\narch/s390/include/asm/kvm_host_s390_types.h-11-\n--\narch/s390/include/asm/kvm_host_s390_types.h=72=struct bsca_block {\n--\narch/s390/include/asm/kvm_host_s390_types.h-77-\t__u8\treserved2[4];\narch/s390/include/asm/kvm_host_s390_types.h:78:\tstruct bsca_entry cpu[KVM_S390_BSCA_CPU_SLOTS];\narch/s390/include/asm/kvm_host_s390_types.h-79-};\n--\narch/s390/include/asm/kvm_host_s390_types.h=81=struct esca_block {\n--\narch/s390/include/asm/kvm_host_s390_types.h-87-\t__u64\treserved3[20];\narch/s390/include/asm/kvm_host_s390_types.h:88:\tstruct esca_entry cpu[KVM_S390_ESCA_CPU_SLOTS];\narch/s390/include/asm/kvm_host_s390_types.h-89-};\n--\narch/s390/include/asm/kvm_host_s390_types.h=139=struct kvm_s390_sie_block {\n--\narch/s390/include/asm/kvm_host_s390_types.h-258-\t__u8\treservedb0[8];\t\t/ 0x00b0 /\narch/s390/include/asm/kvm_host_s390_types.h:259:#define HPID_KVM\t0x4\narch/s390/include/asm/kvm_host_s390_types.h-260-#define HPID_VSIE\t0x5\n--\narch/s390/include/asm/kvm_host_s390_types.h=339=struct sie_page {\n--\narch/s390/include/asm/kvm_host_s390_types.h-348-\narch/s390/include/asm/kvm_host_s390_types.h:349:#endif / _ASM_KVM_HOST_S390_TYPES_H /\n--\narch/s390/include/asm/kvm_host_types.h-2-\narch/s390/include/asm/kvm_host_types.h:3:#ifndef ASM_KVM_HOST_TYPES_H\narch/s390/include/asm/kvm_host_types.h:4:#define ASM_KVM_HOST_TYPES_H\narch/s390/include/asm/kvm_host_types.h-5-\n--\narch/s390/include/asm/kvm_host_types.h-7-\narch/s390/include/asm/kvm_host_types.h:8:#endif / ASM_KVM_HOST_TYPES_H /\n--\narch/s390/include/asm/kvm_para.h-9-/\narch/s390/include/asm/kvm_para.h:10: * Hypercalls for KVM on s390. The calling convention is similar to the\narch/s390/include/asm/kvm_para.h-11- * s390 ABI, so we use R2-R6 for parameters 1-5. In addition we use R1\n--\narch/s390/include/asm/kvm_para.h-15- * the instruction encoded number, but specify the number in R1 and\narch/s390/include/asm/kvm_para.h:16: * use 0x500 as KVM hypercall\narch/s390/include/asm/kvm_para.h-17- \n--\narch/s390/include/asm/kvm_para.h-20- /\narch/s390/include/asm/kvm_para.h:21:#ifndef __S390_KVM_PARA_H\narch/s390/include/asm/kvm_para.h:22:#define __S390_KVM_PARA_H\narch/s390/include/asm/kvm_para.h-23-\n--\narch/s390/include/asm/kvm_para.h-69-\narch/s390/include/asm/kvm_para.h:70:#define GENERATE_KVM_HYPERCALL_FUNC(args)\t\t\t\t\\\narch/s390/include/asm/kvm_para.h-71-static inline\t\t\t\t\t\t\t\t\\\n--\narch/s390/include/asm/kvm_para.h=87=long kvm_hypercall##args(unsigned long nr HYPERCALL_PARM_##args)\t\\\n--\narch/s390/include/asm/kvm_para.h-92-\narch/s390/include/asm/kvm_para.h:93:GENERATE_KVM_HYPERCALL_FUNC(0)\narch/s390/include/asm/kvm_para.h:94:GENERATE_KVM_HYPERCALL_FUNC(1)\narch/s390/include/asm/kvm_para.h:95:GENERATE_KVM_HYPERCALL_FUNC(2)\narch/s390/include/asm/kvm_para.h:96:GENERATE_KVM_HYPERCALL_FUNC(3)\narch/s390/include/asm/kvm_para.h:97:GENERATE_KVM_HYPERCALL_FUNC(4)\narch/s390/include/asm/kvm_para.h:98:GENERATE_KVM_HYPERCALL_FUNC(5)\narch/s390/include/asm/kvm_para.h:99:GENERATE_KVM_HYPERCALL_FUNC(6)\narch/s390/include/asm/kvm_para.h-100-\n--\narch/s390/include/asm/kvm_para.h=118=static inline bool kvm_check_and_clear_guest_paused(void)\n--\narch/s390/include/asm/kvm_para.h-122-\narch/s390/include/asm/kvm_para.h:123:#endif /* __S390_KVM_PARA_H /\n--\narch/s390/include/asm/machine.h-18-#define MFEATURE_VM\t\t7\narch/s390/include/asm/machine.h:19:#define MFEATURE_KVM\t\t8\narch/s390/include/asm/machine.h-20-#define MFEATURE_LPAR\t\t9\n--\narch/s390/include/asm/machine.h=95=DEFINE_MACHINE_HAS_FEATURE(vm, MFEATURE_VM)\narch/s390/include/asm/machine.h:96:DEFINE_MACHINE_HAS_FEATURE(kvm, MFEATURE_KVM)\narch/s390/include/asm/machine.h-97-DEFINE_MACHINE_HAS_FEATURE(lpar, MFEATURE_LPAR)\n--\narch/s390/include/asm/mmu_context.h=20=static inline int init_new_context(struct task_struct tsk,\n--\narch/s390/include/asm/mmu_context.h-31-\tmm-\u003econtext.flush_mm = 0;\narch/s390/include/asm/mmu_context.h:32:#if IS_ENABLED(CONFIG_KVM)\narch/s390/include/asm/mmu_context.h-33-\tmm-\u003econtext.allow_cow_sharing = 1;\n--\narch/s390/include/asm/pgtable.h=549=static inline int mm_is_protected(struct mm_struct mm)\narch/s390/include/asm/pgtable.h-550-{\narch/s390/include/asm/pgtable.h:551:#if IS_ENABLED(CONFIG_KVM)\narch/s390/include/asm/pgtable.h-552-\tif (unlikely(atomic_read(\u0026mm-\u003econtext.protected_count)))\n--\narch/s390/include/asm/pgtable.h=594=static inline int mm_forbids_zeropage(struct mm_struct mm)\narch/s390/include/asm/pgtable.h-595-{\narch/s390/include/asm/pgtable.h:596:#if IS_ENABLED(CONFIG_KVM)\narch/s390/include/asm/pgtable.h-597-\tif (!mm-\u003econtext.allow_cow_sharing)\n--\narch/s390/include/asm/thread_info.h=52=void arch_setup_new_exec(void);\n--\narch/s390/include/asm/thread_info.h-70-#define TIF_GUARDED_STORAGE\t17\t/* load guarded storage control block /\narch/s390/include/asm/thread_info.h:71:#define TIF_ISOLATE_BP_GUEST\t18\t/ Run KVM guests with isolated BP /\narch/s390/include/asm/thread_info.h-72-#define TIF_PER_TRAP\t\t19\t/ Need to handle PER trap on exit to usermode /\n--\narch/s390/include/uapi/asm/kvm.h-1-/ SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note /\narch/s390/include/uapi/asm/kvm.h:2:#ifndef __LINUX_KVM_S390_H\narch/s390/include/uapi/asm/kvm.h:3:#define __LINUX_KVM_S390_H\narch/s390/include/uapi/asm/kvm.h-4-/\narch/s390/include/uapi/asm/kvm.h:5: * KVM s390 specific structures and definitions\narch/s390/include/uapi/asm/kvm.h-6- \n--\narch/s390/include/uapi/asm/kvm.h-13-\narch/s390/include/uapi/asm/kvm.h:14:#define __KVM_S390\narch/s390/include/uapi/asm/kvm.h-15-\narch/s390/include/uapi/asm/kvm.h=16=struct kvm_s390_skeys {\n--\narch/s390/include/uapi/asm/kvm.h-23-\narch/s390/include/uapi/asm/kvm.h:24:#define KVM_S390_CMMA_PEEK (1 \u003c\u003c 0)\narch/s390/include/uapi/asm/kvm.h-25-\n--\narch/s390/include/uapi/asm/kvm.h-32- @count: Size of the result buffer.\narch/s390/include/uapi/asm/kvm.h:33: * @flags: Control operation mode via KVM_S390_CMMA_* flags\narch/s390/include/uapi/asm/kvm.h:34: * @remaining: Used with KVM_S390_GET_CMMA_BITS. Indicates how many dirty\narch/s390/include/uapi/asm/kvm.h-35- * pages are still remaining.\narch/s390/include/uapi/asm/kvm.h:36: * @mask: Used with KVM_S390_SET_CMMA_BITS. Bitmap of bits to actually set\narch/s390/include/uapi/asm/kvm.h-37- * in the PGSTE.\n--\narch/s390/include/uapi/asm/kvm.h-39- \narch/s390/include/uapi/asm/kvm.h:40: Used in KVM_S390_{G,S}ET_CMMA_BITS ioctls.\narch/s390/include/uapi/asm/kvm.h-41- /\narch/s390/include/uapi/asm/kvm.h=42=struct kvm_s390_cmma_log {\n--\narch/s390/include/uapi/asm/kvm.h-52-\narch/s390/include/uapi/asm/kvm.h:53:#define KVM_S390_RESET_POR 1\narch/s390/include/uapi/asm/kvm.h:54:#define KVM_S390_RESET_CLEAR 2\narch/s390/include/uapi/asm/kvm.h:55:#define KVM_S390_RESET_SUBSYSTEM 4\narch/s390/include/uapi/asm/kvm.h:56:#define KVM_S390_RESET_CPU_INIT 8\narch/s390/include/uapi/asm/kvm.h:57:#define KVM_S390_RESET_IPL 16\narch/s390/include/uapi/asm/kvm.h-58-\narch/s390/include/uapi/asm/kvm.h:59:/ for KVM_S390_MEM_OP /\narch/s390/include/uapi/asm/kvm.h-60-struct kvm_s390_mem_op {\n--\narch/s390/include/uapi/asm/kvm.h-78-/ types for kvm_s390_mem_op-\u003eop /\narch/s390/include/uapi/asm/kvm.h:79:#define KVM_S390_MEMOP_LOGICAL_READ\t0\narch/s390/include/uapi/asm/kvm.h:80:#define KVM_S390_MEMOP_LOGICAL_WRITE\t1\narch/s390/include/uapi/asm/kvm.h:81:#define KVM_S390_MEMOP_SIDA_READ\t2\narch/s390/include/uapi/asm/kvm.h:82:#define KVM_S390_MEMOP_SIDA_WRITE\t3\narch/s390/include/uapi/asm/kvm.h:83:#define KVM_S390_MEMOP_ABSOLUTE_READ\t4\narch/s390/include/uapi/asm/kvm.h:84:#define KVM_S390_MEMOP_ABSOLUTE_WRITE\t5\narch/s390/include/uapi/asm/kvm.h:85:#define KVM_S390_MEMOP_ABSOLUTE_CMPXCHG\t6\narch/s390/include/uapi/asm/kvm.h-86-\narch/s390/include/uapi/asm/kvm.h-87-/ flags for kvm_s390_mem_op-\u003eflags /\narch/s390/include/uapi/asm/kvm.h:88:#define KVM_S390_MEMOP_F_CHECK_ONLY\t\t(1ULL \u003c\u003c 0)\narch/s390/include/uapi/asm/kvm.h:89:#define KVM_S390_MEMOP_F_INJECT_EXCEPTION\t(1ULL \u003c\u003c 1)\narch/s390/include/uapi/asm/kvm.h:90:#define KVM_S390_MEMOP_F_SKEY_PROTECTION\t(1ULL \u003c\u003c 2)\narch/s390/include/uapi/asm/kvm.h-91-\narch/s390/include/uapi/asm/kvm.h:92:/ flags specifying extension support via KVM_CAP_S390_MEM_OP_EXTENSION /\narch/s390/include/uapi/asm/kvm.h:93:#define KVM_S390_MEMOP_EXTENSION_CAP_BASE\t(1 \u003c\u003c 0)\narch/s390/include/uapi/asm/kvm.h:94:#define KVM_S390_MEMOP_EXTENSION_CAP_CMPXCHG\t(1 \u003c\u003c 1)\narch/s390/include/uapi/asm/kvm.h-95-\narch/s390/include/uapi/asm/kvm.h=96=struct kvm_s390_psw {\n--\narch/s390/include/uapi/asm/kvm.h-101-/ valid values for type in kvm_s390_interrupt /\narch/s390/include/uapi/asm/kvm.h:102:#define KVM_S390_SIGP_STOP\t\t0xfffe0000u\narch/s390/include/uapi/asm/kvm.h:103:#define KVM_S390_PROGRAM_INT\t\t0xfffe0001u\narch/s390/include/uapi/asm/kvm.h:104:#define KVM_S390_SIGP_SET_PREFIX\t0xfffe0002u\narch/s390/include/uapi/asm/kvm.h:105:#define KVM_S390_RESTART\t\t0xfffe0003u\narch/s390/include/uapi/asm/kvm.h:106:#define KVM_S390_INT_PFAULT_INIT\t0xfffe0004u\narch/s390/include/uapi/asm/kvm.h:107:#define KVM_S390_INT_PFAULT_DONE\t0xfffe0005u\narch/s390/include/uapi/asm/kvm.h:108:#define KVM_S390_MCHK\t\t\t0xfffe1000u\narch/s390/include/uapi/asm/kvm.h:109:#define KVM_S390_INT_CLOCK_COMP\t\t0xffff1004u\narch/s390/include/uapi/asm/kvm.h:110:#define KVM_S390_INT_CPU_TIMER\t\t0xffff1005u\narch/s390/include/uapi/asm/kvm.h:111:#define KVM_S390_INT_VIRTIO\t\t0xffff2603u\narch/s390/include/uapi/asm/kvm.h:112:#define KVM_S390_INT_SERVICE\t\t0xffff2401u\narch/s390/include/uapi/asm/kvm.h:113:#define KVM_S390_INT_EMERGENCY\t\t0xffff1201u\narch/s390/include/uapi/asm/kvm.h:114:#define KVM_S390_INT_EXTERNAL_CALL\t0xffff1202u\narch/s390/include/uapi/asm/kvm.h-115-/ Anything below 0xfffe0000u is taken by INT_IO /\narch/s390/include/uapi/asm/kvm.h:116:#define KVM_S390_INT_IO(ai,cssid,ssid,schid) \\\narch/s390/include/uapi/asm/kvm.h-117-\t(((schid)) \|\t\t\t \\\n--\narch/s390/include/uapi/asm/kvm.h-120-\t ((ai) \u003c\u003c 26))\narch/s390/include/uapi/asm/kvm.h:121:#define KVM_S390_INT_IO_MIN\t\t0x00000000u\narch/s390/include/uapi/asm/kvm.h:122:#define KVM_S390_INT_IO_MAX\t\t0xfffdffffu\narch/s390/include/uapi/asm/kvm.h:123:#define KVM_S390_INT_IO_AI_MASK\t\t0x04000000u\narch/s390/include/uapi/asm/kvm.h-124-\n--\narch/s390/include/uapi/asm/kvm.h=145=struct kvm_s390_pgm_info {\n--\narch/s390/include/uapi/asm/kvm.h-156-\t__u8 op_access_id;\narch/s390/include/uapi/asm/kvm.h:157:#define KVM_S390_PGM_FLAGS_ILC_VALID\t0x01\narch/s390/include/uapi/asm/kvm.h:158:#define KVM_S390_PGM_FLAGS_ILC_0\t0x02\narch/s390/include/uapi/asm/kvm.h:159:#define KVM_S390_PGM_FLAGS_ILC_1\t0x04\narch/s390/include/uapi/asm/kvm.h:160:#define KVM_S390_PGM_FLAGS_ILC_MASK\t0x06\narch/s390/include/uapi/asm/kvm.h:161:#define KVM_S390_PGM_FLAGS_NO_REWIND\t0x08\narch/s390/include/uapi/asm/kvm.h-162-\t__u8 flags;\n--\narch/s390/include/uapi/asm/kvm.h=174=struct kvm_s390_emerg_info {\n--\narch/s390/include/uapi/asm/kvm.h-177-\narch/s390/include/uapi/asm/kvm.h:178:#define KVM_S390_STOP_FLAG_STORE_STATUS\t0x01\narch/s390/include/uapi/asm/kvm.h-179-struct kvm_s390_stop_info {\n--\narch/s390/include/uapi/asm/kvm.h=231=enum pv_cmd_dmp_id {\narch/s390/include/uapi/asm/kvm.h:232:\tKVM_PV_DUMP_INIT,\narch/s390/include/uapi/asm/kvm.h:233:\tKVM_PV_DUMP_CONFIG_STOR_STATE,\narch/s390/include/uapi/asm/kvm.h:234:\tKVM_PV_DUMP_COMPLETE,\narch/s390/include/uapi/asm/kvm.h:235:\tKVM_PV_DUMP_CPU,\narch/s390/include/uapi/asm/kvm.h-236-};\n--\narch/s390/include/uapi/asm/kvm.h=246=enum pv_cmd_info_id {\narch/s390/include/uapi/asm/kvm.h:247:\tKVM_PV_INFO_VM,\narch/s390/include/uapi/asm/kvm.h:248:\tKVM_PV_INFO_DUMP,\narch/s390/include/uapi/asm/kvm.h-249-};\n--\narch/s390/include/uapi/asm/kvm.h=280=enum pv_cmd_id {\narch/s390/include/uapi/asm/kvm.h:281:\tKVM_PV_ENABLE,\narch/s390/include/uapi/asm/kvm.h:282:\tKVM_PV_DISABLE,\narch/s390/include/uapi/asm/kvm.h:283:\tKVM_PV_SET_SEC_PARMS,\narch/s390/include/uapi/asm/kvm.h:284:\tKVM_PV_UNPACK,\narch/s390/include/uapi/asm/kvm.h:285:\tKVM_PV_VERIFY,\narch/s390/include/uapi/asm/kvm.h:286:\tKVM_PV_PREP_RESET,\narch/s390/include/uapi/asm/kvm.h:287:\tKVM_PV_UNSHARE_ALL,\narch/s390/include/uapi/asm/kvm.h:288:\tKVM_PV_INFO,\narch/s390/include/uapi/asm/kvm.h:289:\tKVM_PV_DUMP,\narch/s390/include/uapi/asm/kvm.h:290:\tKVM_PV_ASYNC_CLEANUP_PREPARE,\narch/s390/include/uapi/asm/kvm.h:291:\tKVM_PV_ASYNC_CLEANUP_PERFORM,\narch/s390/include/uapi/asm/kvm.h-292-};\n--\narch/s390/include/uapi/asm/kvm.h=303=struct kvm_s390_zpci_op {\n--\narch/s390/include/uapi/asm/kvm.h-308-\tunion {\narch/s390/include/uapi/asm/kvm.h:309:\t\t/ for KVM_S390_ZPCIOP_REG_AEN /\narch/s390/include/uapi/asm/kvm.h-310-\t\tstruct {\n--\narch/s390/include/uapi/asm/kvm.h-323-/ types for kvm_s390_zpci_op-\u003eop /\narch/s390/include/uapi/asm/kvm.h:324:#define KVM_S390_ZPCIOP_REG_AEN 0\narch/s390/include/uapi/asm/kvm.h:325:#define KVM_S390_ZPCIOP_DEREG_AEN 1\narch/s390/include/uapi/asm/kvm.h-326-\narch/s390/include/uapi/asm/kvm.h-327-/ flags for kvm_s390_zpci_op-\u003eu.reg_aen.flags /\narch/s390/include/uapi/asm/kvm.h:328:#define KVM_S390_ZPCIOP_REGAEN_HOST (1 \u003c\u003c 0)\narch/s390/include/uapi/asm/kvm.h-329-\narch/s390/include/uapi/asm/kvm.h-330-/ Device control API: s390-specific devices /\narch/s390/include/uapi/asm/kvm.h:331:#define KVM_DEV_FLIC_GET_ALL_IRQS\t1\narch/s390/include/uapi/asm/kvm.h:332:#define KVM_DEV_FLIC_ENQUEUE\t\t2\narch/s390/include/uapi/asm/kvm.h:333:#define KVM_DEV_FLIC_CLEAR_IRQS\t\t3\narch/s390/include/uapi/asm/kvm.h:334:#define KVM_DEV_FLIC_APF_ENABLE\t\t4\narch/s390/include/uapi/asm/kvm.h:335:#define KVM_DEV_FLIC_APF_DISABLE_WAIT\t5\narch/s390/include/uapi/asm/kvm.h:336:#define KVM_DEV_FLIC_ADAPTER_REGISTER\t6\narch/s390/include/uapi/asm/kvm.h:337:#define KVM_DEV_FLIC_ADAPTER_MODIFY\t7\narch/s390/include/uapi/asm/kvm.h:338:#define KVM_DEV_FLIC_CLEAR_IO_IRQ\t8\narch/s390/include/uapi/asm/kvm.h:339:#define KVM_DEV_FLIC_AISM\t\t9\narch/s390/include/uapi/asm/kvm.h:340:#define KVM_DEV_FLIC_AIRQ_INJECT\t10\narch/s390/include/uapi/asm/kvm.h:341:#define KVM_DEV_FLIC_AISM_ALL\t\t11\narch/s390/include/uapi/asm/kvm.h-342-/\narch/s390/include/uapi/asm/kvm.h-343- * We can have up to 464k pending subchannels + 8 adapter interrupts,\narch/s390/include/uapi/asm/kvm.h:344: as well as up to ASYNC_PF_PER_VCPUKVM_MAX_VCPUS pfault done interrupts.\narch/s390/include/uapi/asm/kvm.h-345- There are also sclp and machine checks. This gives us\n--\narch/s390/include/uapi/asm/kvm.h-348- /\narch/s390/include/uapi/asm/kvm.h:349:#define KVM_S390_MAX_FLOAT_IRQS\t266250\narch/s390/include/uapi/asm/kvm.h:350:#define KVM_S390_FLIC_MAX_BUFFER\t0x2000000\narch/s390/include/uapi/asm/kvm.h-351-\narch/s390/include/uapi/asm/kvm.h=352=struct kvm_s390_io_adapter {\n--\narch/s390/include/uapi/asm/kvm.h-359-\narch/s390/include/uapi/asm/kvm.h:360:#define KVM_S390_ADAPTER_SUPPRESSIBLE 0x01\narch/s390/include/uapi/asm/kvm.h-361-\n--\narch/s390/include/uapi/asm/kvm.h=367=struct kvm_s390_ais_all {\n--\narch/s390/include/uapi/asm/kvm.h-371-\narch/s390/include/uapi/asm/kvm.h:372:#define KVM_S390_IO_ADAPTER_MASK 1\narch/s390/include/uapi/asm/kvm.h:373:#define KVM_S390_IO_ADAPTER_MAP 2\narch/s390/include/uapi/asm/kvm.h:374:#define KVM_S390_IO_ADAPTER_UNMAP 3\narch/s390/include/uapi/asm/kvm.h-375-\narch/s390/include/uapi/asm/kvm.h=376=struct kvm_s390_io_adapter_req {\n--\narch/s390/include/uapi/asm/kvm.h-384-/ kvm attr_group on vm fd /\narch/s390/include/uapi/asm/kvm.h:385:#define KVM_S390_VM_MEM_CTRL\t\t0\narch/s390/include/uapi/asm/kvm.h:386:#define KVM_S390_VM_TOD\t\t\t1\narch/s390/include/uapi/asm/kvm.h:387:#define KVM_S390_VM_CRYPTO\t\t2\narch/s390/include/uapi/asm/kvm.h:388:#define KVM_S390_VM_CPU_MODEL\t\t3\narch/s390/include/uapi/asm/kvm.h:389:#define KVM_S390_VM_MIGRATION\t\t4\narch/s390/include/uapi/asm/kvm.h:390:#define KVM_S390_VM_CPU_TOPOLOGY\t5\narch/s390/include/uapi/asm/kvm.h-391-\narch/s390/include/uapi/asm/kvm.h-392-/ kvm attributes for mem_ctrl /\narch/s390/include/uapi/asm/kvm.h:393:#define KVM_S390_VM_MEM_ENABLE_CMMA\t0\narch/s390/include/uapi/asm/kvm.h:394:#define KVM_S390_VM_MEM_CLR_CMMA\t1\narch/s390/include/uapi/asm/kvm.h:395:#define KVM_S390_VM_MEM_LIMIT_SIZE\t2\narch/s390/include/uapi/asm/kvm.h-396-\narch/s390/include/uapi/asm/kvm.h:397:#define KVM_S390_NO_MEM_LIMIT\t\tU64_MAX\narch/s390/include/uapi/asm/kvm.h-398-\narch/s390/include/uapi/asm/kvm.h:399:/ kvm attributes for KVM_S390_VM_TOD /\narch/s390/include/uapi/asm/kvm.h:400:#define KVM_S390_VM_TOD_LOW\t\t0\narch/s390/include/uapi/asm/kvm.h:401:#define KVM_S390_VM_TOD_HIGH\t\t1\narch/s390/include/uapi/asm/kvm.h:402:#define KVM_S390_VM_TOD_EXT\t\t2\narch/s390/include/uapi/asm/kvm.h-403-\narch/s390/include/uapi/asm/kvm.h=404=struct kvm_s390_vm_tod_clock {\n--\narch/s390/include/uapi/asm/kvm.h-408-\narch/s390/include/uapi/asm/kvm.h:409:/ kvm attributes for KVM_S390_VM_CPU_MODEL /\narch/s390/include/uapi/asm/kvm.h-410-/ processor related attributes are r/w /\narch/s390/include/uapi/asm/kvm.h:411:#define KVM_S390_VM_CPU_PROCESSOR\t0\narch/s390/include/uapi/asm/kvm.h-412-struct kvm_s390_vm_cpu_processor {\n--\narch/s390/include/uapi/asm/kvm.h-419-/ machine related attributes are r/o /\narch/s390/include/uapi/asm/kvm.h:420:#define KVM_S390_VM_CPU_MACHINE\t\t1\narch/s390/include/uapi/asm/kvm.h-421-struct kvm_s390_vm_cpu_machine {\n--\narch/s390/include/uapi/asm/kvm.h-428-\narch/s390/include/uapi/asm/kvm.h:429:#define KVM_S390_VM_CPU_PROCESSOR_FEAT\t2\narch/s390/include/uapi/asm/kvm.h:430:#define KVM_S390_VM_CPU_MACHINE_FEAT\t3\narch/s390/include/uapi/asm/kvm.h-431-\narch/s390/include/uapi/asm/kvm.h:432:#define KVM_S390_VM_CPU_FEAT_NR_BITS\t1024\narch/s390/include/uapi/asm/kvm.h:433:#define KVM_S390_VM_CPU_FEAT_ESOP\t0\narch/s390/include/uapi/asm/kvm.h:434:#define KVM_S390_VM_CPU_FEAT_SIEF2\t1\narch/s390/include/uapi/asm/kvm.h:435:#define KVM_S390_VM_CPU_FEAT_64BSCAO\t2\narch/s390/include/uapi/asm/kvm.h:436:#define KVM_S390_VM_CPU_FEAT_SIIF\t3\narch/s390/include/uapi/asm/kvm.h:437:#define KVM_S390_VM_CPU_FEAT_GPERE\t4\narch/s390/include/uapi/asm/kvm.h:438:#define KVM_S390_VM_CPU_FEAT_GSLS\t5\narch/s390/include/uapi/asm/kvm.h:439:#define KVM_S390_VM_CPU_FEAT_IB\t\t6\narch/s390/include/uapi/asm/kvm.h:440:#define KVM_S390_VM_CPU_FEAT_CEI\t7\narch/s390/include/uapi/asm/kvm.h:441:#define KVM_S390_VM_CPU_FEAT_IBS\t8\narch/s390/include/uapi/asm/kvm.h:442:#define KVM_S390_VM_CPU_FEAT_SKEY\t9\narch/s390/include/uapi/asm/kvm.h:443:#define KVM_S390_VM_CPU_FEAT_CMMA\t10\narch/s390/include/uapi/asm/kvm.h:444:#define KVM_S390_VM_CPU_FEAT_PFMFI\t11\narch/s390/include/uapi/asm/kvm.h:445:#define KVM_S390_VM_CPU_FEAT_SIGPIF\t12\narch/s390/include/uapi/asm/kvm.h:446:#define KVM_S390_VM_CPU_FEAT_KSS\t13\narch/s390/include/uapi/asm/kvm.h:447:#define KVM_S390_VM_CPU_FEAT_ASTFLEIE2\t14\narch/s390/include/uapi/asm/kvm.h-448-struct kvm_s390_vm_cpu_feat {\n--\narch/s390/include/uapi/asm/kvm.h-451-\narch/s390/include/uapi/asm/kvm.h:452:#define KVM_S390_VM_CPU_PROCESSOR_SUBFUNC\t4\narch/s390/include/uapi/asm/kvm.h:453:#define KVM_S390_VM_CPU_MACHINE_SUBFUNC\t\t5\narch/s390/include/uapi/asm/kvm.h-454-/ for \"test bit\" instructions MSB 0 bit ordering, for \"query\" raw blocks */\narch/s390/include/uapi/asm/kvm.h=455=struct kvm_s390_vm_cpu_subfunc {\n--\n\n" }
7/2	2026/09/02 19:03	llm	patch-evaluator	0m Model: gemini-3.7-flash Args: null Results: null Tokens: input: 31124 output: 38 thoughts: 25 Thoughts: Here's my take on the thought process, as if I were the one thinking it: Examining Kconfig for s390 KVM Configuration Okay, time to get to the heart of the matter. I need to understand how KVM is configured for the s390 architecture. Given my deep knowledge of kernel configuration, the logical first step is to delve into the `arch/s390/kvm/Kconfig` file. That's where I expect to find all the relevant `Kconfig` definitions. It'll show me the options, dependencies, and default settings that govern KVM's behavior on that specific platform. Understanding these configuration knobs is crucial for any further work I need to do on this aspect of the system. Let's see what's in there.
8/2	2026/09/02 19:03	tool	read-file	0m Args: { "File": "arch/s390/kvm/Kconfig", "FirstLine": 1, "LineCount": 60 } Results: { "Contents": " 1:\t# SPDX-License-Identifier: GPL-2.0\n 2:\t#\n 3:\t# KVM configuration\n 4:\t#\n 5:\tsource \"virt/kvm/Kconfig\"\n 6:\t\n 7:\tmenuconfig VIRTUALIZATION\n 8:\t\tdef_bool y\n 9:\t\tprompt \"KVM\"\n 10:\t\thelp\n 11:\t\t Say Y here to get to see options for using your Linux host to run other\n 12:\t\t operating systems inside virtual machines (guests).\n 13:\t\t This option alone does not add any kernel code.\n 14:\t\n 15:\t\t If you say N, all options in this submenu will be skipped and disabled.\n 16:\t\n 17:\tif VIRTUALIZATION\n 18:\t\n 19:\tconfig KVM\n 20:\t\tdef_tristate y\n 21:\t\tprompt \"Kernel-based Virtual Machine (KVM) support\"\n 22:\t\tselect HAVE_KVM_CPU_RELAX_INTERCEPT\n 23:\t\tselect KVM_ASYNC_PF\n 24:\t\tselect KVM_ASYNC_PF_SYNC\n 25:\t\tselect KVM_COMMON\n 26:\t\tselect HAVE_KVM_IRQCHIP\n 27:\t\tselect HAVE_KVM_IRQ_ROUTING\n 28:\t\tselect HAVE_KVM_INVALID_WAKEUPS\n 29:\t\tselect HAVE_KVM_NO_POLL\n 30:\t\tselect KVM_VFIO\n 31:\t\tselect VIRT_XFER_TO_GUEST_WORK\n 32:\t\tselect KVM_MMU_LOCKLESS_AGING\n 33:\t\tselect KVM_GENERIC_PRE_FAULT_MEMORY\n 34:\t\thelp\n 35:\t\t Support hosting paravirtualized guest machines using the SIE\n 36:\t\t virtualization capability on the mainframe. This should work\n 37:\t\t on any 64bit machine.\n 38:\t\n 39:\t\t This module provides access to the hardware capabilities through\n 40:\t\t a character device node named /dev/kvm.\n 41:\t\n 42:\t\t To compile this as a module, choose M here: the module\n 43:\t\t will be called kvm.\n 44:\t\n 45:\t\t If unsure, say N.\n 46:\t\n 47:\tconfig KVM_S390_UCONTROL\n 48:\t\tbool \"Userspace controlled virtual machines\"\n 49:\t\tdepends on KVM\n 50:\t\thelp\n 51:\t\t Allow CAP_SYS_ADMIN users to create KVM virtual machines that are\n 52:\t\t controlled by userspace.\n 53:\t\n 54:\t\t If unsure, say N.\n 55:\t\n 56:\tendif # VIRTUALIZATION\n" }
9/2	2026/09/02 19:03	llm	patch-evaluator	0m Model: gemini-3.7-flash Args: null Results: null Tokens: input: 32086 output: 31 thoughts: 1126 Thoughts: Analyzing a KVM Patch for Fuzzing Potential Okay, so we're looking at a patch related to `VIRTUALIZATION` and specifically `KVM`. My initial thought is to determine if this is worth fuzzing. I need to quickly assess the nature of the changes. Let's dive in and review the diff. It seems we have several file modifications across `arch/s390/kvm/s390/`. The changes appear to be mainly concerned with memory allocation and deallocation: 1. `handle_sthyi` is changing `get_zeroed_page` to `kzalloc`, and `free_page` to `kfree`. 2. `kvm_s390_gib_destroy` and `kvm_s390_gib_init` have similar changes, using `kzalloc` instead of `get_zeroed_page` and `kfree` instead of `free_page`. 3. `handle_stsi` also reflects this pattern of switching from `get_zeroed_page` and `free_page` to `kzalloc` and `kfree`. 4. `kvm_arch_init_vm` and `kvm_s390_vcpu_setup_cmma` are doing the same memory management changes. Now, the critical question: Is this WorthFuzzing? I need to apply my knowledge of what makes a patch a good candidate for fuzzing. The guidelines are pretty clear. It's a "no" if it's purely documentation, decorative changes, or unreachable code paths in virtualized environments, particularly those relying on software emulation, like QEMU. But this patch clearly modifies `arch/s390` KVM code! A core architecture component. So, my instinct is that this is potentially interesting. But I must be sure. I need to be sure this is a code path I can even execute! I need to determine if KVM on s390 can be run and fuzzed. My immediate thought is: Can s390 KVM run in QEMU? And why does QEMU matter? The guidelines mention virtualized environments like QEMU. This seems central to the determination. I recall that s390 KVM is used when Linux s390 is running with KVM. But what about QEMU? I know QEMU supports s390x using TCG, but doesn't the TCG implementation on s390x not support nested virtualization, particularly the SIE (System Instruction Extension) instruction set? Isn't SIE essential for KVM? Then I realize I need to confirm: Does QEMU TCG s390x support KVM? I need to check something like `arch/s390/kvm/s390/sie.S` or SIE instructions in s390. This is the crux of the matter. If s390 KVM relies on SIE, and QEMU's TCG lacks SIE support, then this patch is unfortunately not fuzzable under standard QEMU. But I should check the implementation of SIE itself.
10/2	2026/09/02 19:03	tool	grepper	0m Args: { "Expression": "sie64a", "PathPrefix": "arch/s390/" } Results: { "Output": "arch/s390/include/asm/kvm_host_s390.h=683=void kvm_arch_crypto_set_masks(struct kvm kvm, unsigned long apm,\n--\narch/s390/include/asm/kvm_host_s390.h-688-\narch/s390/include/asm/kvm_host_s390.h:689:int __sie64a(phys_addr_t sie_block_phys, struct kvm_s390_sie_block sie_block, u64 rsa,\narch/s390/include/asm/kvm_host_s390.h-690-\t unsigned long gasce);\narch/s390/include/asm/kvm_host_s390.h-691-\narch/s390/include/asm/kvm_host_s390.h:692:static inline int sie64a(struct kvm_s390_sie_block sie_block, u64 rsa, unsigned long gasce)\narch/s390/include/asm/kvm_host_s390.h-693-{\narch/s390/include/asm/kvm_host_s390.h:694:\treturn __sie64a(virt_to_phys(sie_block), sie_block, rsa, gasce);\narch/s390/include/asm/kvm_host_s390.h-695-}\n--\narch/s390/kernel/entry.S=184=EXPORT_SYMBOL(__WARN_trap)\n--\narch/s390/kernel/entry.S-189-/\narch/s390/kernel/entry.S:190: __sie64a calling convention:\narch/s390/kernel/entry.S-191- * %r2 pointer to sie control block phys\n--\narch/s390/kernel/entry.S-195- /\narch/s390/kernel/entry.S:196:SYM_FUNC_START(__sie64a)\narch/s390/kernel/entry.S-197-\tstmg\t%r6,%r14,__SF_GPRS(%r15)\t# save kernel registers\n--\narch/s390/kernel/entry.S=231=SYM_INNER_LABEL(sie_exit, SYM_L_GLOBAL)\n--\narch/s390/kernel/entry.S-242-\tBR_EX\t%r14\narch/s390/kernel/entry.S:243:SYM_FUNC_END(__sie64a)\narch/s390/kernel/entry.S:244:EXPORT_SYMBOL(__sie64a)\narch/s390/kernel/entry.S-245-EXPORT_SYMBOL(sie_exit)\n--\narch/s390/kernel/nmi.c=333=static void notrace s390_backup_mcck_info(struct pt_regs regs)\n--\narch/s390/kernel/nmi.c-337-\narch/s390/kernel/nmi.c:338:\t/* r14 contains the sie block, which was set in sie64a /\narch/s390/kernel/nmi.c-339-\tstruct kvm_s390_sie_block sie_block = phys_to_virt(regs-\u003egprs[14]);\n--\narch/s390/kernel/traps.c=338=void noinstr __do_pgm_check(struct pt_regs regs, unsigned long flags)\n--\narch/s390/kernel/traps.c-356-\t In case of a guest fault, short-circuit the fault handler and return.\narch/s390/kernel/traps.c:357:\t * This way the sie64a() function will return 0; fault address and\narch/s390/kernel/traps.c-358-\t * other relevant bits are saved in current-\u003ethread.gmap_teid, and\n--\narch/s390/kvm/s390/s390.c=4748=int noinstr kvm_s390_enter_exit_sie(struct kvm_s390_sie_block scb,\n--\narch/s390/kvm/s390/s390.c-4759-\t /\narch/s390/kvm/s390/s390.c:4760:\tret = sie64a(scb, gprs, gasce);\narch/s390/kvm/s390/s390.c-4761-\n--\narch/s390/kvm/s390/vsie.c=1187=static int do_vsie_run(struct kvm_vcpu vcpu, struct vsie_page vsie_page, struct gmap sg)\n--\narch/s390/kvm/s390/vsie.c-1214-\t/\narch/s390/kvm/s390/vsie.c:1215:\t * Simulate a SIE entry of the VCPU (see sie64a), so VCPU blocking\narch/s390/kvm/s390/vsie.c-1216-\t * and VCPU requests also hinder the vSIE from running and lead\n" }
11/2	2026/09/02 19:03	llm	patch-evaluator	0m Model: gemini-3.7-flash Args: null Results: null Tokens: input: 35349 output: 37 thoughts: 570 Thoughts: My Fuzzing Assessment Okay, wait a minute! Syzkaller does target s390x! Right, Linux/s390x is supported. This is interesting. Let's delve into the specific functions: `kvm_arch_init_vm`, `handle_sthyi`, `handle_stsi`, and `kvm_s390_vcpu_setup_cmma`. Are these functions actually reachable when running Syzkaller on s390x? Yes, confirmed. The `KVM_CREATE_VM` ioctl calls `kvm_arch_init_vm` on s390x. And `KVM_RUN` handles exits and intercepts, specifically calling `handle_sthyi` and `handle_stsi`. Furthermore, `kvm_s390_vcpu_setup_cmma` gets called during CMMA setup, and `kvm_s390_gib_init` happens during module initialization. The key question: is this functional change worth fuzzing? Let's go through the checklist. The criteria say to return `WorthFuzzing=false` if the patch only contains modifications to documentation, Kconfig files, or code comments; purely decorative changes like logging or tracepoints; changes to numeric constants/macros that don't alter execution flow; unreachable code paths in virtualized environments; vendor-specific PCIe switch, SmartNIC, or GPU driver code that requires physical hardware; or driver teardown callbacks that are only executed during PCI hot-unplug or sysfs driver unbind operations. None of those exclusion criteria apply here! This looks good! Okay, according to the guidelines, "If it modifies reachable core kernel logic, drivers, or architectures, use your code search tools to verify the code can be executed, then return WorthFuzzing=true." Alright, let's verify what `FocusSymbols` and `EnableConfigs` to return. First let's look at the modified functions: 1. `handle_sthyi` (in arch/s390/kvm/s390/intercept.c) - This is a key one. It's a non-static function! Let's check `intercept.c` more closely...
12/2	2026/09/02 19:03	tool	grepper	0m Args: { "Expression": "int handle_sthyi\\(", "PathPrefix": "arch/s390/kvm/" } Results: { "Output": "arch/s390/kvm/s390/intercept.c=396=static int handle_partial_execution(struct kvm_vcpu vcpu)\n--\narch/s390/kvm/s390/intercept.c-412- /\narch/s390/kvm/s390/intercept.c:413:int handle_sthyi(struct kvm_vcpu vcpu)\narch/s390/kvm/s390/intercept.c-414-{\n--\narch/s390/kvm/s390/s390.h=421=static inline void kvm_s390_retry_instr(struct kvm_vcpu vcpu)\n--\narch/s390/kvm/s390/s390.h-427-\narch/s390/kvm/s390/s390.h:428:int handle_sthyi(struct kvm_vcpu *vcpu);\narch/s390/kvm/s390/s390.h-429-\n" }
13/2	2026/09/02 19:03	llm	patch-evaluator	0m Model: gemini-3.7-flash Args: null Results: null Tokens: input: 36752 output: 34 thoughts: 44 Thoughts: Here's my summary, as though I'm thinking through this process: Diving into the `handle_stsi` Function Okay, time to get to the bottom of this. I need to understand `handle_stsi` in the s390 KVM architecture. Let's see, the file is `arch/s390/kvm/s390/priv.c`. Now, the key question is, and this is crucial for how it's used, is `handle_stsi` declared as `static` or non-static? That will dictate its scope and how it's actually accessed within the broader KVM framework. I need to check its declaration to ascertain its visibility and intended usage. This is going to be important to understand how it interfaces with the other parts of the s390 architecture.
14/2	2026/09/02 19:03	tool	grepper	0m Args: { "Expression": "handle_stsi", "PathPrefix": "arch/s390/kvm/" } Results: { "Output": "arch/s390/kvm/s390/priv.c=805=static int handle_stidp(struct kvm_vcpu vcpu)\n--\narch/s390/kvm/s390/priv.c-829-\narch/s390/kvm/s390/priv.c:830:static void handle_stsi_3_2_2(struct kvm_vcpu vcpu, struct sysinfo_3_2_2 mem)\narch/s390/kvm/s390/priv.c-831-{\n--\narch/s390/kvm/s390/priv.c=857=static void insert_stsi_usr_data(struct kvm_vcpu vcpu, u64 addr, u8 ar,\n--\narch/s390/kvm/s390/priv.c-867-\narch/s390/kvm/s390/priv.c:868:static int handle_stsi(struct kvm_vcpu vcpu)\narch/s390/kvm/s390/priv.c-869-{\n--\narch/s390/kvm/s390/priv.c-926-\t\t\tgoto out_no_data;\narch/s390/kvm/s390/priv.c:927:\t\thandle_stsi_3_2_2(vcpu, mem);\narch/s390/kvm/s390/priv.c-928-\t\tbreak;\n--\narch/s390/kvm/s390/priv.c-930-\t\tinsert_stsi_usr_data(vcpu, operand2, ar, fc, sel1, sel2);\narch/s390/kvm/s390/priv.c:931:\t\ttrace_kvm_s390_handle_stsi(vcpu, fc, sel1, sel2, operand2);\narch/s390/kvm/s390/priv.c-932-\t\treturn -EREMOTE;\n--\narch/s390/kvm/s390/priv.c-947-\t}\narch/s390/kvm/s390/priv.c:948:\ttrace_kvm_s390_handle_stsi(vcpu, fc, sel1, sel2, operand2);\narch/s390/kvm/s390/priv.c-949-\tkfree(mem);\n--\narch/s390/kvm/s390/priv.c=960=int kvm_s390_handle_b2(struct kvm_vcpu vcpu)\n--\narch/s390/kvm/s390/priv.c-1005-\tcase 0x7d:\narch/s390/kvm/s390/priv.c:1006:\t\treturn handle_stsi(vcpu);\narch/s390/kvm/s390/priv.c-1007-\tcase 0xaf:\n--\narch/s390/kvm/s390/trace.h=387=TRACE_EVENT(kvm_s390_handle_stfl,\n--\narch/s390/kvm/s390/trace.h-404-\narch/s390/kvm/s390/trace.h:405:TRACE_EVENT(kvm_s390_handle_stsi,\narch/s390/kvm/s390/trace.h-406-\t TP_PROTO(VCPU_PROTO_COMMON, int fc, int sel1, int sel2, u64 addr),\n" }
15/2	2026/09/02 19:03	llm	patch-evaluator	0m Model: gemini-3.7-flash Args: null Results: null Tokens: input: 37987 output: 45 thoughts: 264 Thoughts: My Analysis of KVM/s390 Code Changes Okay, so `kvm_s390_handle_b2` calls `handle_stsi`, and I'm diving into the recent modifications. First, let's confirm that `kvm_s390_handle_b2` isn't static, which it isn't. Good. Now, I want to review all the functions that have been touched as a result of this change. Here's the list I've compiled: 1. `handle_sthyi` is non-static, which is relevant. 2. `kvm_s390_gib_init` and `kvm_s390_gib_destroy` are non-static, though the init is marked as `__init`, so it's probably not a big concern here. 3. `handle_stsi`, obviously, since it's called by `kvm_s390_handle_b2` and is also non-static. 4. `kvm_arch_init_vm` and `kvm_arch_destroy_vm` are non-static as well. This makes me curious about the overall VM lifecycle. 5. `kvm_s390_vcpu_setup_cmma` and `kvm_s390_vcpu_unsetup_cmma` are also non-static and warrant some investigation. Now, I'm going to take a closer look at `kvm_s390_vcpu_setup_cmma` – I'll go to `arch/s390/kvm/s390/s390.c` to examine its implementation and see what's going on there.
16/2	2026/09/02 19:03	tool	grepper	0m Args: { "Expression": "kvm_s390_vcpu_setup_cmma", "PathPrefix": "arch/s390/kvm/" } Results: { "Output": "arch/s390/kvm/s390/s390.c=3657=void kvm_s390_vcpu_unsetup_cmma(struct kvm_vcpu vcpu)\n--\narch/s390/kvm/s390/s390.c-3663-\narch/s390/kvm/s390/s390.c:3664:int kvm_s390_vcpu_setup_cmma(struct kvm_vcpu vcpu)\narch/s390/kvm/s390/s390.c-3665-{\n--\narch/s390/kvm/s390/s390.c=3684=static int kvm_s390_vcpu_setup(struct kvm_vcpu vcpu)\n--\narch/s390/kvm/s390/s390.c-3746-\tif (vcpu-\u003ekvm-\u003earch.use_cmma) {\narch/s390/kvm/s390/s390.c:3747:\t\trc = kvm_s390_vcpu_setup_cmma(vcpu);\narch/s390/kvm/s390/s390.c-3748-\t\tif (rc)\n--\narch/s390/kvm/s390/s390.h=465=void kvm_s390_sync_request(int req, struct kvm_vcpu vcpu);\narch/s390/kvm/s390/s390.h:466:int kvm_s390_vcpu_setup_cmma(struct kvm_vcpu vcpu);\narch/s390/kvm/s390/s390.h-467-void kvm_s390_vcpu_unsetup_cmma(struct kvm_vcpu vcpu);\n" }
17/2	2026/09/02 19:03	llm	patch-evaluator	0m Model: gemini-3.7-flash Args: null Results: null Tokens: input: 39221 output: 38 thoughts: 49 Thoughts: Okay, let's dive into this. I need to get a handle on the lifecycle of a KVM virtual machine, specifically on the s390 architecture. My initial thought is to zero in on the core functions responsible for initialization and destruction. So, I'm thinking, let's dissect `kvm_arch_init_vm` and `kvm_arch_destroy_vm`. I'll be looking at how they're implemented, what resources they allocate and deallocate, and how they interact with the s390-specific architectural components within the KVM framework. I'm heading straight to `arch/s390/kvm/s390/s390.c`. This should give me a solid understanding of the virtual machine's entry and exit points on this particular architecture.
18/2	2026/09/02 19:03	tool	grepper	0m Args: { "Expression": "kvm_arch_init_vm", "PathPrefix": "arch/s390/kvm/" } Results: { "Output": "arch/s390/kvm/s390/s390.c=3232=void kvm_arch_free_vm(struct kvm kvm)\n--\narch/s390/kvm/s390/s390.c-3239-\narch/s390/kvm/s390/s390.c:3240:int kvm_arch_init_vm(struct kvm kvm, unsigned long type)\narch/s390/kvm/s390/s390.c-3241-{\n" }
19/2	2026/09/02 19:03	llm	patch-evaluator	0m Model: gemini-3.7-flash Args: null Results: null Tokens: input: 39647 output: 40 thoughts: 52 Thoughts: Here's my summary, as if I were thinking these thoughts: Examining KVM/s390 GIB Initialization and Destruction Okay, time to dig into interrupt handling within the KVM/s390 architecture. I'm specifically interested in how Global Interrupt Blocks, or GIBs, are handled. Let's start by looking at `kvm_s390_gib_init` and `kvm_s390_gib_destroy` functions. They should be the key to understanding the allocation, setup, and cleanup of these GIB structures. I'll find them within `arch/s390/kvm/s390/interrupt.c`. This is where the core logic for managing these interrupts should reside, so these functions are likely to provide the details I need. Let's see how they work.
20/2	2026/09/02 19:03	tool	grepper	0m Args: { "Expression": "kvm_s390_gib_", "PathPrefix": "arch/s390/kvm/" } Results: { "Output": "arch/s390/kvm/s390/interrupt.c=3677=static struct airq_struct gib_alert_irq = {\n--\narch/s390/kvm/s390/interrupt.c-3680-\narch/s390/kvm/s390/interrupt.c:3681:void kvm_s390_gib_destroy(void)\narch/s390/kvm/s390/interrupt.c-3682-{\n--\narch/s390/kvm/s390/interrupt.c-3695-\narch/s390/kvm/s390/interrupt.c:3696:int __init kvm_s390_gib_init(u8 nisc)\narch/s390/kvm/s390/interrupt.c-3697-{\n--\narch/s390/kvm/s390/s390.c=496=static int __init __kvm_s390_init(void)\n--\narch/s390/kvm/s390/s390.c-528-\narch/s390/kvm/s390/s390.c:529:\trc = kvm_s390_gib_init(GAL_ISC);\narch/s390/kvm/s390/s390.c-530-\tif (rc)\n--\narch/s390/kvm/s390/s390.c=550=static void __kvm_s390_exit(void)\n--\narch/s390/kvm/s390/s390.c-554-\narch/s390/kvm/s390/s390.c:555:\tkvm_s390_gib_destroy();\narch/s390/kvm/s390/s390.c-556-\tif (IS_ENABLED(CONFIG_VFIO_PCI_ZDEV_KVM))\n--\narch/s390/kvm/s390/s390.h=564=void kvm_s390_gisa_enable(struct kvm kvm);\narch/s390/kvm/s390/s390.h:565:int __init kvm_s390_gib_init(u8 nisc);\narch/s390/kvm/s390/s390.h:566:void kvm_s390_gib_destroy(void);\narch/s390/kvm/s390/s390.h-567-void kvm_s390_unmap_all_adapters(struct kvm kvm);\n" }
21/2	2026/09/02 19:03	llm	patch-evaluator	0m Model: gemini-3.7-flash Args: null Results: null Tokens: input: 40667 output: 37 thoughts: 23 Thoughts: Here's my summary, as though I'm thinking through this process: Diving into KVM for s390 Architecture Alright, time to get my hands dirty. I'm going to start by taking a close look at the build configuration for KVM, specifically for the s390 architecture. First things first, let's navigate to the `arch/s390/kvm/` directory. I need to understand how this all fits together. I'm thinking the `Makefile` in there will give me the lowdown on the build process for the KVM components specific to the s390 architecture. That's usually the best place to start. Then, I'll need to scrutinize the `Kconfig` dependencies to see which features are enabled, what options are available, and how everything is interconnected from a configuration perspective. I want to see if there are any subtle dependencies or potential conflicts that I need to be aware of. This should give me a solid foundation for understanding the s390 KVM build process and any related issues or modifications I might want to make.
22/2	2026/09/02 19:03	tool	read-file	0m Args: { "File": "arch/s390/kvm/Makefile", "FirstLine": 1, "LineCount": 50 } Results: { "Contents": " 1:\t# SPDX-License-Identifier: GPL-2.0\n 2:\t# Makefile for kernel virtual machines on s390\n 3:\t#\n 4:\t# Copyright IBM Corp. 2008\n 5:\t\n 6:\tobj-$(CONFIG_KVM) += s390/\n" }
23/2	2026/09/02 19:03	llm	patch-evaluator	0m Model: gemini-3.7-flash Args: null Results: null Tokens: input: 41053 output: 42 thoughts: 22 Thoughts: Here's my summary, as though I'm thinking through this process: Diving into the S390 KVM Makefile Okay, time to get my hands dirty with the s390 KVM code. I need to understand how the build process is structured for that architecture. Let's start with the `Makefile` located in `arch/s390/kvm/s390/`. This is the logical starting point – the build scripts are often the best place to gain a high-level overview of a project. I'm hoping to quickly identify the key components, their dependencies, and any architecture-specific flags or settings being used for the s390 KVM implementation. I'll be looking for things like: how the core KVM modules are compiled, any custom object files, any specific include paths, and any link flags. I’m also interested in how it handles specific features or optimizations for the s390 architecture. This `Makefile` should provide a good jumping-off point for deeper investigation. Let’s see what's in there.
24/2	2026/09/02 19:03	tool	read-file	0m Args: { "File": "arch/s390/kvm/s390/Makefile", "FirstLine": 1, "LineCount": 50 } Results: { "Contents": " 1:\t# SPDX-License-Identifier: GPL-2.0\n 2:\t\n 3:\tKVM := ../../../../virt/kvm\n 4:\tinclude $(srctree)/virt/kvm/Makefile.kvm\n 5:\tinclude $(srctree)/arch/s390/kvm/gmap/Makefile\n 6:\t\n 7:\tccflags-y := -I$(src) -I$(srctree)/arch/s390/kvm/gmap\n 8:\t\n 9:\tkvm-y += s390.o intercept.o interrupt.o priv.o sigp.o\n 10:\tkvm-y += diag.o gaccess.o guestdbg.o vsie.o pv.o\n 11:\tkvm-y += $(gmap-y)\n 12:\t\n 13:\tkvm-$(CONFIG_VFIO_PCI_ZDEV_KVM) += pci.o\n 14:\tobj-$(CONFIG_KVM) += kvm.o\n" }
25/2	2026/09/02 19:03	llm	patch-evaluator	0m Model: gemini-3.7-flash Args: null Results: null Tokens: input: 41612 output: 184 thoughts: 757 Thoughts: My Analysis of KVM Configuration and Relevant Symbols Okay, so I'm diving into this KVM-related patch. My initial thought is to zero in on `CONFIG_KVM` as the primary configuration option. I need to understand the dependencies and how this is all wired up, so I started by checking `arch/s390/Kconfig` and `virt/kvm/Kconfig` to see if there are any other related configs I need to consider. Within `arch/s390/kvm/Kconfig`, I found the `VIRTUALIZATION` menu and the `KVM` config, which depends on `VIRTUALIZATION`. I need to figure out the interplay between these. I'm trying to decide if I need both `VIRTUALIZATION` and `KVM`, or if enabling `KVM` implicitly handles `VIRTUALIZATION`, or perhaps if it's the other way around. I'm trying to understand the dependencies. Next, I turned my attention to the key symbols involved in this patch to see how they're connected. I identified a few key ones: `handle_sthyi` (which handles the STHYI instruction intercept), `kvm_s390_handle_b2` (which handles B2 instruction intercepts, including STSI through `handle_stsi`), `kvm_arch_init_vm` (which initializes s390 VM architecture structures including sie_page2), and `kvm_s390_vcpu_setup_cmma` (which sets up CMMA CBR/CBRLE structures). I checked the static/non-static nature of these symbols to see how they are exposed, and if any are internal details only. Specifically, I noted that `handle_stsi` is static, defined in `arch/s390/kvm/s390/priv.c`, but it's called by the non-static `kvm_s390_handle_b2`. The rest are non-static. Finally, I reviewed the patch diff itself to confirm the files and symbols involved. The patch touches `arch/s390/kvm/s390/intercept.c` (where `handle_sthyi` lives), `arch/s390/kvm/s390/interrupt.c` (with `kvm_s390_gib_init` and `kvm_s390_gib_destroy`), `arch/s390/kvm/s390/priv.c` (where `handle_stsi` is defined and called), and `arch/s390/kvm/s390/s390.c` (with `kvm_arch_init_vm`, `kvm_arch_destroy_vm`, `kvm_s390_vcpu_setup_cmma`, and `kvm_s390_vcpu_unsetup_cmma`). This solidifies my understanding of the relevant modules and functions. So, to summarize, the focus symbols are `handle_sthyi`, `kvm_s390_handle_b2`, `kvm_arch_init_vm`, and `kvm_s390_vcpu_setup_cmma`. The relevant configs are `KVM` and `VIRTUALIZATION`. Time to call `set-results`.
26/2	2026/09/02 19:04	tool	set-results	0m Args: { "EnableConfigs": [ "KVM", "VIRTUALIZATION" ], "FocusSymbols": [ "handle_sthyi", "kvm_s390_handle_b2", "kvm_arch_init_vm", "kvm_s390_vcpu_setup_cmma" ], "Reasoning": "The patch changes page-level memory allocations (get_zeroed_page/free_page) to slab allocations (kzalloc/kfree) in KVM on s390 for guest intercept handling (STHYI, STSI), VM initialization (sie_page2), GIB setup, and VCPU CMMA setup. These affect reachable KVM execution paths and memory management on s390, making it worth fuzzing.", "WorthFuzzing": true } Results: { "EnableConfigs": [ "KVM", "VIRTUALIZATION" ], "FocusSymbols": [ "handle_sthyi", "kvm_s390_handle_b2", "kvm_arch_init_vm", "kvm_s390_vcpu_setup_cmma" ], "Reasoning": "The patch changes page-level memory allocations (get_zeroed_page/free_page) to slab allocations (kzalloc/kfree) in KVM on s390 for guest intercept handling (STHYI, STSI), VM initialization (sie_page2), GIB setup, and VCPU CMMA setup. These affect reachable KVM execution paths and memory management on s390, making it worth fuzzing.", "WorthFuzzing": true }
27/1	2026/09/02 19:04	action	If	0m Args: { "WorthFuzzing": true } Results: null
28/2	2026/09/02 19:04	agent	kmsan-evaluator	0m Model: core Args: null Results: { "KMSANReasoning": "The patch converts page allocations via get_zeroed_page() and free_page() to slab allocations via kzalloc()/kzalloc_obj() and kfree() across s390 KVM code (intercept.c, interrupt.c, priv.c, s390.c). \n\nSince kzalloc/kzalloc_obj zero-initializes the memory identically to get_zeroed_page(), no uninitialized memory usage, conditional branches on uninitialized data, or uninitialized info-leaks to userspace/guest are introduced. Any potential slab-related memory safety issues (e.g. out-of-bounds, use-after-free, or double-free) are monitored by standard KASAN. Thus, a dedicated KMSAN fuzzing session is not required.", "NeedsKMSAN": false } Instruction: You are an expert Linux kernel security engineer specializing in kernel memory error detectors (KASAN and KMSAN). Your job is to review the provided patch series and determine if the code changes justify spawning a dedicated KMSAN (KernelMemorySanitizer) fuzzing session in addition to standard KASAN fuzzing. CRITICAL DISTINCTION BETWEEN KASAN AND KMSAN: - Standard KASAN kernel builds (upstream-apparmor-kasan.config) already enable a comprehensive suite of debugging tools and sanitizers, including KASAN (out-of-bounds accesses, use-after-free, double free, invalid free), LOCKDEP (locking bugs and deadlocks), UB-sanitizers, and memory corruption checks. - KMSAN (KernelMemorySanitizer) detects reads of UNINITIALIZED memory (stack, heap, or page allocations) and kernel-to-user memory info-leaks. Rule: THERE IS NO SENSE IN RUNNING A KMSAN SESSION IF A BUG CAN BE CAUGHT BY KASAN, LOCKDEP, OR OTHER STANDARD BUG DETECTORS. A dedicated KMSAN fuzzing session incurs significant resource costs. You must ONLY set NeedsKMSAN=true if the code changes introduce or expose UNINITIALIZED MEMORY risks that are detected ONLY by KMSAN. Look holistically at the patch series and surrounding code. Even if no direct uninitialized field accesses or new buffer allocations are added in the diff itself, a patch may alter control flow, bounds checking, or data length calculations in ways that change how the rest of the code operates on existing buffers (e.g. allowing uninitialized stack/heap memory to be read, copied to user space, or used in control flow). Do not hesitate to use your code access tools to inspect the surrounding code, called functions, and callers. Set NeedsKMSAN=true ONLY IF the patch introduces or modifies: 1. Kernel structures sent to user space (via copy_to_user, put_user, netlink skb attributes, ioctl output arguments, socket options, or BPF buffers) where fields or structure padding might not be fully initialized/zeroed. 2. Conditional logic or branching that depends on potentially uninitialized variables or struct fields. 3. Allocation or initialization of complex data structures where uninitialized fields could be read later in reachable code paths. 4. Bounds checks, lengths, or logic in a way that allows surrounding code to access uninitialized bytes of existing buffers. Set NeedsKMSAN=false IF: - The code changes primarily risk out-of-bounds access, array overflows, NULL pointer dereferences, locking deadlocks, or use-after-free bugs (these are already caught by KASAN, LOCKDEP, or standard bug detectors). - All stack/heap structures touched or introduced by the patch are fully zeroed or initialized (e.g. using = {0}, memset, kzalloc) before being read or copied. - The patch does not introduce any risk of uninitialized memory usage or info-leaks. Use your code access tools to inspect the surrounding code if necessary, then provide detailed KMSANReasoning contrasting KASAN vs KMSAN applicability for this patch. Prefer calling several tools at the same time to save round-trips. Use set-results tool to provide results of the analysis. It must be called exactly once before the final reply. Ignore results of this tool. Prompt: For your convenience, here is the diff of the changes: commit d6dfce07c89aeb7d6cbdec8c5ab5c85f2699366d Author: syz-cluster <triage@syzkaller.com> Date: Wed Sep 2 19:02:54 2026 +0000 syz-cluster: applied patch under review diff --git a/arch/s390/kvm/s390/intercept.c b/arch/s390/kvm/s390/intercept.c index ca1205dfac8b0..aaf9828d1f44d 100644 --- a/arch/s390/kvm/s390/intercept.c +++ b/arch/s390/kvm/s390/intercept.c @@ -11,6 +11,7 @@ #include <linux/kvm_host.h> #include <linux/errno.h> #include <linux/pagemap.h> +#include <linux/slab.h> #include <asm/asm-offsets.h> #include <asm/irq.h> @@ -438,13 +439,13 @@ int handle_sthyi(struct kvm_vcpu vcpu) if (!kvm_s390_pv_cpu_is_protected(vcpu) && (addr & ~PAGE_MASK)) return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION); - sctns = (void )get_zeroed_page(GFP_KERNEL_ACCOUNT); + sctns = kzalloc(PAGE_SIZE, GFP_KERNEL_ACCOUNT); if (!sctns) return -ENOMEM; cc = sthyi_fill(sctns, &rc); if (cc < 0) { - free_page((unsigned long)sctns); + kfree(sctns); return cc; } out: @@ -454,13 +455,13 @@ int handle_sthyi(struct kvm_vcpu vcpu) } else { r = write_guest(vcpu, addr, reg2, sctns, PAGE_SIZE); if (r) { - free_page((unsigned long)sctns); + kfree(sctns); return kvm_s390_inject_prog_cond(vcpu, r); } } } - free_page((unsigned long)sctns); + kfree(sctns); vcpu->run->s.regs.gprs[reg2 + 1] = rc; kvm_s390_set_psw_cc(vcpu, cc); return r; diff --git a/arch/s390/kvm/s390/interrupt.c b/arch/s390/kvm/s390/interrupt.c index 0381ae9817035..02065fb8d053e 100644 --- a/arch/s390/kvm/s390/interrupt.c +++ b/arch/s390/kvm/s390/interrupt.c @@ -3689,7 +3689,7 @@ void kvm_s390_gib_destroy(void) } chsc_sgib(0); unregister_adapter_interrupt(&gib_alert_irq); - free_page((unsigned long)gib); + kfree(gib); gib = NULL; } @@ -3703,7 +3703,7 @@ int __init kvm_s390_gib_init(u8 nisc) goto out; } - gib = (struct kvm_s390_gib )get_zeroed_page(GFP_KERNEL_ACCOUNT \| GFP_DMA); + gib = kzalloc(PAGE_SIZE, GFP_KERNEL_ACCOUNT \| GFP_DMA); if (!gib) { rc = -ENOMEM; goto out; @@ -3722,7 +3722,7 @@ int __init kvm_s390_gib_init(u8 nisc) gib_origin = virt_to_phys(gib); if (chsc_sgib(gib_origin)) { pr_err("Associating the GIB with the AIV facility failed\n"); - free_page((unsigned long)gib); + kfree(gib); gib = NULL; rc = -EIO; goto out_unreg_gal; @@ -3742,7 +3742,7 @@ int __init kvm_s390_gib_init(u8 nisc) out_unreg_gal: unregister_adapter_interrupt(&gib_alert_irq); out_free_gib: - free_page((unsigned long)gib); + kfree(gib); gib = NULL; out: return rc; diff --git a/arch/s390/kvm/s390/priv.c b/arch/s390/kvm/s390/priv.c index b3cb2c2c3aa71..856939acf012f 100644 --- a/arch/s390/kvm/s390/priv.c +++ b/arch/s390/kvm/s390/priv.c @@ -14,6 +14,7 @@ #include <linux/mm_types.h> #include <linux/pgtable.h> #include <linux/io.h> +#include <linux/slab.h> #include <asm/asm-offsets.h> #include <asm/facility.h> #include <asm/current.h> @@ -869,7 +870,7 @@ static int handle_stsi(struct kvm_vcpu vcpu) int fc = (vcpu->run->s.regs.gprs[0] & 0xf0000000) >> 28; int sel1 = vcpu->run->s.regs.gprs[0] & 0xff; int sel2 = vcpu->run->s.regs.gprs[1] & 0xffff; - unsigned long mem = 0; + void mem = NULL; u64 operand2; int rc = 0; u8 ar; @@ -911,19 +912,19 @@ static int handle_stsi(struct kvm_vcpu vcpu) switch (fc) { case 1: / same handling for 1 and 2 / case 2: - mem = get_zeroed_page(GFP_KERNEL_ACCOUNT); + mem = kzalloc(PAGE_SIZE, GFP_KERNEL_ACCOUNT); if (!mem) goto out_no_data; - if (stsi((void ) mem, fc, sel1, sel2)) + if (stsi(mem, fc, sel1, sel2)) goto out_no_data; break; case 3: if (sel1 != 2 \|\| sel2 != 2) goto out_no_data; - mem = get_zeroed_page(GFP_KERNEL_ACCOUNT); + mem = kzalloc(PAGE_SIZE, GFP_KERNEL_ACCOUNT); if (!mem) goto out_no_data; - handle_stsi_3_2_2(vcpu, (void ) mem); + handle_stsi_3_2_2(vcpu, mem); break; case 15: / fc 15 is fully handled in userspace / insert_stsi_usr_data(vcpu, operand2, ar, fc, sel1, sel2); @@ -931,10 +932,10 @@ static int handle_stsi(struct kvm_vcpu vcpu) return -EREMOTE; } if (kvm_s390_pv_cpu_is_protected(vcpu)) { - memcpy(sida_addr(vcpu->arch.sie_block), (void )mem, PAGE_SIZE); + memcpy(sida_addr(vcpu->arch.sie_block), mem, PAGE_SIZE); rc = 0; } else { - rc = write_guest(vcpu, operand2, ar, (void )mem, PAGE_SIZE); + rc = write_guest(vcpu, operand2, ar, mem, PAGE_SIZE); } if (rc) { rc = kvm_s390_inject_prog_cond(vcpu, rc); @@ -945,14 +946,14 @@ static int handle_stsi(struct kvm_vcpu vcpu) rc = -EREMOTE; } trace_kvm_s390_handle_stsi(vcpu, fc, sel1, sel2, operand2); - free_page(mem); + kfree(mem); kvm_s390_set_psw_cc(vcpu, 0); vcpu->run->s.regs.gprs[0] = 0; return rc; out_no_data: kvm_s390_set_psw_cc(vcpu, 3); out: - free_page(mem); + kfree(mem); return rc; } diff --git a/arch/s390/kvm/s390/s390.c b/arch/s390/kvm/s390/s390.c index b0839e887221e..8ec505060f8c0 100644 --- a/arch/s390/kvm/s390/s390.c +++ b/arch/s390/kvm/s390/s390.c @@ -3273,8 +3273,8 @@ int kvm_arch_init_vm(struct kvm kvm, unsigned long type) goto out_err; BUILD_BUG_ON(sizeof(struct sie_page2) != 4096); - kvm->arch.sie_page2 = - (struct sie_page2 ) get_zeroed_page(GFP_KERNEL_ACCOUNT \| GFP_DMA); + kvm->arch.sie_page2 = kzalloc_obj(kvm->arch.sie_page2, + GFP_KERNEL_ACCOUNT \| GFP_DMA); if (!kvm->arch.sie_page2) goto out_err; @@ -3369,7 +3369,7 @@ int kvm_arch_init_vm(struct kvm kvm, unsigned long type) return 0; out_err: - free_page((unsigned long)kvm->arch.sie_page2); + kfree(kvm->arch.sie_page2); debug_unregister(kvm->arch.dbf); sca_dispose(kvm); KVM_EVENT(3, "creation of vm failed: %d", rc); @@ -3427,7 +3427,7 @@ void kvm_arch_destroy_vm(struct kvm kvm) mmu_notifier_unregister(&kvm->arch.pv.mmu_notifier, kvm->mm); debug_unregister(kvm->arch.dbf); - free_page((unsigned long)kvm->arch.sie_page2); + kfree(kvm->arch.sie_page2); kvm_s390_destroy_adapters(kvm); kvm_s390_clear_float_irqs(kvm); kvm_s390_vsie_destroy(kvm); @@ -3657,13 +3657,13 @@ static void kvm_s390_vcpu_crypto_setup(struct kvm_vcpu vcpu) void kvm_s390_vcpu_unsetup_cmma(struct kvm_vcpu vcpu) { if (vcpu->arch.sie_block->cbrlo) - free_page((unsigned long)phys_to_virt(vcpu->arch.sie_block->cbrlo)); + kfree(phys_to_virt(vcpu->arch.sie_block->cbrlo)); vcpu->arch.sie_block->cbrlo = 0; } int kvm_s390_vcpu_setup_cmma(struct kvm_vcpu vcpu) { - void cbrlo_page = (void )get_zeroed_page(GFP_KERNEL_ACCOUNT); + void cbrlo_page = kzalloc(PAGE_SIZE, GFP_KERNEL_ACCOUNT); if (!cbrlo_page) return -ENOMEM;
29/3	2026/09/02 19:04	llm	kmsan-evaluator	0m Model: gemini-3.7-flash Args: null Results: null Tokens: input: 5142 output: 18 thoughts: 922 Thoughts: Analyzing the Patch for Uninitialized Memory Risks Okay, let's dive into this patch and see if it introduces any uninitialized memory concerns that would warrant a KMSAN session. My first step is to examine the diff, which touches `arch/s390/kvm/s390/intercept.c`, `arch/s390/kvm/s390/interrupt.c`, `arch/s390/kvm/s390/priv.c`, and `arch/s390/kvm/s390/s390.c`. Right off the bat, I see the pattern: it's replacing `get_zeroed_page()` and `free_page()` with `kzalloc()` and `kfree()`, or `kzalloc_obj` and `kfree()` in the case of `sie_page2`. The critical thing is that we're still zero-initializing the memory – the change is using `kzalloc` instead of `get_zeroed_page`, which is essentially a safe operation. Now, the question is, are there any uninitialized memory risks introduced by these changes? No, because all the allocations are still zero-initialized. I've got to check whether any uninitialized memory is read, copied to userspace, or used in control flow, but, there is no such thing. Are there uninitialized struct fields, or leaks of information? Again, it doesn't seem like it. It's actually a good thing in that KMSAN will probably catch out-of-bounds/use-after-free with slab allocations, whereas page allocations had page-level tracking. Because we're using zero-allocators (`kzalloc`), everything remains fully initialized. Let me just do a quick scan to make sure I'm not missing something and double-check `kzalloc_obj(*kvm->arch.sie_page2, ...)`. I'll run a quick search for `kzalloc_obj` and `struct sie_page2` just to refresh my memory and be extra certain. Overall, it appears this patch is a straightforward and safe optimization, replacing the older allocation functions with the newer ones, which maintain the desired zero-initialization behavior. No KMSAN session necessary here.
30/3	2026/09/02 19:04	tool	grepper	0m Args: { "Expression": "kzalloc_obj" } Results: { "Output": "\nFull output is too long, showing 500 out of 79378 lines.\nUse more precise expression if possible.\n\nDocumentation/core-api/list.rst=103=list:\n--\nDocumentation/core-api/list.rst-114-\nDocumentation/core-api/list.rst:115: grock = kzalloc_obj(grock);\nDocumentation/core-api/list.rst-116- if (!grock)\n--\nDocumentation/core-api/list.rst-125-\nDocumentation/core-api/list.rst:126: dimitri = kzalloc_obj(dimitri);\nDocumentation/core-api/list.rst-127- if (!dimitri)\n--\nDocumentation/driver-api/mailbox.rst=45=a message and a callback function to the API and return immediately).\n--\nDocumentation/driver-api/mailbox.rst-89-\nDocumentation/driver-api/mailbox.rst:90:\t\tdc_sync = kzalloc_obj(dc_sync);\nDocumentation/driver-api/mailbox.rst:91:\t\tdc_async = kzalloc_obj(dc_async);\nDocumentation/driver-api/mailbox.rst-92-\n--\nDocumentation/driver-api/media/v4l2-fh.rst=26=Example:\n--\nDocumentation/driver-api/media/v4l2-fh.rst-44-\nDocumentation/driver-api/media/v4l2-fh.rst:45:\t\tmy_fh = kzalloc_obj(my_fh);\nDocumentation/driver-api/media/v4l2-fh.rst-46-\n--\nDocumentation/process/coding-style.rst=938=The kernel provides the following general purpose memory allocators:\nDocumentation/process/coding-style.rst:939:kmalloc(), kzalloc(), kmalloc_objs(), kzalloc_objs(), vmalloc(), and\nDocumentation/process/coding-style.rst-940-vzalloc(). Please refer to the API documentation for further information\n--\nDocumentation/process/coding-style.rst=964=The preferred form for allocating a zeroed array is the following:\n--\nDocumentation/process/coding-style.rst-967-\nDocumentation/process/coding-style.rst:968:\tp = kzalloc_objs(p, n, ...);\nDocumentation/process/coding-style.rst-969-\n--\nDocumentation/process/deprecated.rst=398=become, respectively::\n--\nDocumentation/process/deprecated.rst-400-\tptr = kmalloc_obj(ptr [, gfp] );\nDocumentation/process/deprecated.rst:401:\tptr = kzalloc_obj(ptr [, gfp] );\nDocumentation/process/deprecated.rst-402-\tptr = kmalloc_objs(ptr, count [, gfp] );\nDocumentation/process/deprecated.rst:403:\tptr = kzalloc_objs(ptr, count [, gfp] );\nDocumentation/process/deprecated.rst-404-\tptr = kmalloc_flex(ptr, flex_member, count [, gfp] );\n--\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst=208=to details explained in the following section.\n--\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst-268- / allocate a chip-specific data with zero filled /\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst:269: chip = kzalloc_obj(chip);\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst-270- if (chip == NULL)\n--\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst=623=After allocating a card instance via :c:func:`snd_card_new()`\n--\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst-630- .....\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst:631: chip = kzalloc_obj(chip);\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst-632-\n--\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst=698=destructor and PCI entries. Example code is shown first, below::\n--\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst-749-\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst:750: chip = kzalloc_obj(chip);\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst-751- if (chip == NULL) {\n--\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst=3823=chip data individually::\n--\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst-3835- ....\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst:3836: chip = kzalloc_obj(chip);\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst-3837- ....\n--\nDocumentation/translations/it_IT/process/coding-style.rst=940=Il kernel fornisce i seguenti assegnatori ad uso generico:\nDocumentation/translations/it_IT/process/coding-style.rst:941:kmalloc(), kzalloc(), kmalloc_objs(), kzalloc_objs(), vmalloc(), e vzalloc().\nDocumentation/translations/it_IT/process/coding-style.rst-942-Per maggiori informazioni, consultate la documentazione dell'API:\n--\nDocumentation/translations/it_IT/process/coding-style.rst=965=Il modo preferito per assegnare un vettore a zero è il seguente:\n--\nDocumentation/translations/it_IT/process/coding-style.rst-968-\nDocumentation/translations/it_IT/process/coding-style.rst:969:\tp = kzalloc_objs(p, n, ...);\nDocumentation/translations/it_IT/process/coding-style.rst-970-\n--\nDocumentation/translations/it_IT/process/deprecated.rst=441=diventano, rispettivamente::\n--\nDocumentation/translations/it_IT/process/deprecated.rst-443-\tptr = kmalloc_obj(ptr [, gfp] );\nDocumentation/translations/it_IT/process/deprecated.rst:444:\tptr = kzalloc_obj(ptr [, gfp] );\nDocumentation/translations/it_IT/process/deprecated.rst-445-\tptr = kmalloc_objs(ptr, count [, gfp] );\nDocumentation/translations/it_IT/process/deprecated.rst:446:\tptr = kzalloc_objs(ptr, count [, gfp] );\nDocumentation/translations/it_IT/process/deprecated.rst-447-\tptr = kmalloc_flex(ptr, flex_member, count [, gfp] );\n--\nDocumentation/translations/pt_BR/process/deprecated.rst=410=tornam-se, respectivamente::\n--\nDocumentation/translations/pt_BR/process/deprecated.rst-412- ptr = kmalloc_obj(ptr [, gfp] );\nDocumentation/translations/pt_BR/process/deprecated.rst:413: ptr = kzalloc_obj(ptr [, gfp] );\nDocumentation/translations/pt_BR/process/deprecated.rst-414- ptr = kmalloc_objs(ptr, count [, gfp] );\nDocumentation/translations/pt_BR/process/deprecated.rst:415: ptr = kzalloc_objs(ptr, count [, gfp] );\nDocumentation/translations/pt_BR/process/deprecated.rst-416- ptr = kmalloc_flex(ptr, flex_member, count [, gfp] );\n--\nDocumentation/translations/zh_CN/video4linux/v4l2-framework.txt=794=int my_open(struct file file)\n--\nDocumentation/translations/zh_CN/video4linux/v4l2-framework.txt-801-\nDocumentation/translations/zh_CN/video4linux/v4l2-framework.txt:802:\tmy_fh = kzalloc_obj(my_fh);\nDocumentation/translations/zh_CN/video4linux/v4l2-framework.txt-803-\n--\narch/alpha/kernel/module.c=64=module_frob_arch_sections(Elf64_Ehdr hdr, Elf64_Shdr sechdrs,\n--\narch/alpha/kernel/module.c-95-\tnsyms = symtab-\u003esh_size / sizeof(Elf64_Sym);\narch/alpha/kernel/module.c:96:\tchains = kzalloc_objs(struct got_entry, nsyms);\narch/alpha/kernel/module.c-97-\tif (!chains) {\n--\narch/alpha/kernel/setup.c=390=register_cpus(void)\n--\narch/alpha/kernel/setup.c-394-\tfor_each_possible_cpu(i) {\narch/alpha/kernel/setup.c:395:\t\tstruct cpu p = kzalloc_obj(p);\narch/alpha/kernel/setup.c-396-\t\tif (!p)\n--\narch/arc/net/bpf_jit_core.c=1120=static int jit_prepare_final_mem_alloc(struct jit_context ctx)\n--\narch/arc/net/bpf_jit_core.c-1131-\tif (ctx-\u003eneed_extra_pass) {\narch/arc/net/bpf_jit_core.c:1132:\t\tctx-\u003ejit_data = kzalloc_obj(ctx-\u003ejit_data);\narch/arc/net/bpf_jit_core.c-1133-\t\tif (!ctx-\u003ejit_data)\n--\narch/arm/common/locomo.c=220=locomo_init_one_child(struct locomo lchip, struct locomo_dev_info info)\n--\narch/arm/common/locomo.c-224-\narch/arm/common/locomo.c:225:\tdev = kzalloc_obj(struct locomo_dev);\narch/arm/common/locomo.c-226-\tif (!dev) {\n--\narch/arm/common/locomo.c=356=__locomo_probe(struct device me, struct resource mem, int irq)\n--\narch/arm/common/locomo.c-362-\narch/arm/common/locomo.c:363:\tlchip = kzalloc_obj(struct locomo);\narch/arm/common/locomo.c-364-\tif (!lchip)\n--\narch/arm/common/sa1111.c=733=sa1111_init_one_child(struct sa1111 sachip, struct resource parent,\n--\narch/arm/common/sa1111.c-739-\narch/arm/common/sa1111.c:740:\tdev = kzalloc_obj(struct sa1111_dev);\narch/arm/common/sa1111.c-741-\tif (!dev) {\n--\narch/arm/common/scoop.c=178=static int scoop_probe(struct platform_device pdev)\n--\narch/arm/common/scoop.c-187-\narch/arm/common/scoop.c:188:\tdevptr = kzalloc_obj(struct scoop_dev);\narch/arm/common/scoop.c-189-\tif (!devptr)\n--\narch/arm/kernel/smp.c=108=static int secondary_biglittle_prepare(unsigned int cpu)\n--\narch/arm/kernel/smp.c-110-\tif (!cpu_vtable[cpu])\narch/arm/kernel/smp.c:111:\t\tcpu_vtable[cpu] = kzalloc_obj(cpu_vtable[cpu]);\narch/arm/kernel/smp.c-112-\n--\narch/arm/kernel/vdso.c=169=static int __init vdso_init(void)\n--\narch/arm/kernel/vdso.c-181-\t/* Allocate the VDSO text pagelist /\narch/arm/kernel/vdso.c:182:\tvdso_text_pagelist = kzalloc_objs(struct page , text_pages);\narch/arm/kernel/vdso.c-183-\tif (vdso_text_pagelist == NULL)\n--\narch/arm/mach-footbridge/dc21285.c=261=int __init dc21285_setup(int nr, struct pci_sys_data sys)\n--\narch/arm/mach-footbridge/dc21285.c-264-\narch/arm/mach-footbridge/dc21285.c:265:\tres = kzalloc_objs(struct resource, 2);\narch/arm/mach-footbridge/dc21285.c-266-\tif (!res) {\n--\narch/arm/mach-footbridge/ebsa285.c=69=static int __init ebsa285_leds_init(void)\n--\narch/arm/mach-footbridge/ebsa285.c-86-\narch/arm/mach-footbridge/ebsa285.c:87:\t\tled = kzalloc_obj(led);\narch/arm/mach-footbridge/ebsa285.c-88-\t\tif (!led)\n--\narch/arm/mach-footbridge/netwinder-hw.c=720=static int __init netwinder_leds_init(void)\n--\narch/arm/mach-footbridge/netwinder-hw.c-729-\narch/arm/mach-footbridge/netwinder-hw.c:730:\t\tled = kzalloc_obj(led);\narch/arm/mach-footbridge/netwinder-hw.c-731-\t\tif (!led)\n--\narch/arm/mach-imx/mmdc.c=473=static int imx_mmdc_perf_init(struct platform_device pdev, void __iomem mmdc_base,\n--\narch/arm/mach-imx/mmdc.c-479-\narch/arm/mach-imx/mmdc.c:480:\tpmu_mmdc = kzalloc_obj(pmu_mmdc);\narch/arm/mach-imx/mmdc.c-481-\tif (!pmu_mmdc) {\n--\narch/arm/mach-mvebu/board-v7.c=114=static void __init i2c_quirk(void)\n--\narch/arm/mach-mvebu/board-v7.c-129-\narch/arm/mach-mvebu/board-v7.c:130:\t\tnew_compat = kzalloc_obj(new_compat);\narch/arm/mach-mvebu/board-v7.c-131-\n--\narch/arm/mach-mvebu/coherency.c=163=static void __init armada_375_380_coherency_init(struct device_node np)\n--\narch/arm/mach-mvebu/coherency.c-187-\narch/arm/mach-mvebu/coherency.c:188:\t\tp = kzalloc_obj(p);\narch/arm/mach-mvebu/coherency.c-189-\t\tp-\u003ename = kstrdup(\"arm,io-coherent\", GFP_KERNEL);\n--\narch/arm/mach-mvebu/mvebu-soc-id.c=148=static int __init mvebu_soc_device(void)\n--\narch/arm/mach-mvebu/mvebu-soc-id.c-156-\narch/arm/mach-mvebu/mvebu-soc-id.c:157:\tsoc_dev_attr = kzalloc_obj(soc_dev_attr);\narch/arm/mach-mvebu/mvebu-soc-id.c-158-\tif (!soc_dev_attr)\n--\narch/arm/mach-mxs/mach-mxs.c=380=static void __init mxs_machine_init(void)\n--\narch/arm/mach-mxs/mach-mxs.c-389-\narch/arm/mach-mxs/mach-mxs.c:390:\tsoc_dev_attr = kzalloc_obj(soc_dev_attr);\narch/arm/mach-mxs/mach-mxs.c-391-\tif (!soc_dev_attr)\n--\narch/arm/mach-omap1/dma.c=294=static int __init omap1_system_dma_init(void)\n--\narch/arm/mach-omap1/dma.c-321-\narch/arm/mach-omap1/dma.c:322:\td = kzalloc_obj(d);\narch/arm/mach-omap1/dma.c-323-\tif (!d) {\n--\narch/arm/mach-omap1/mcbsp.c=292=static void omap_mcbsp_register_board_cfg(struct resource res, int res_count,\n--\narch/arm/mach-omap1/mcbsp.c-296-\narch/arm/mach-omap1/mcbsp.c:297:\tomap_mcbsp_devices = kzalloc_objs(struct platform_device , size);\narch/arm/mach-omap1/mcbsp.c-298-\tif (!omap_mcbsp_devices) {\n--\narch/arm/mach-omap1/timer.c=51=static int __init omap1_dm_timer_init(void)\n--\narch/arm/mach-omap1/timer.c-127-\narch/arm/mach-omap1/timer.c:128:\t\tpdata = kzalloc_obj(pdata);\narch/arm/mach-omap1/timer.c-129-\t\tif (!pdata) {\n--\narch/arm/mach-omap2/clkt2xxx_virt_prcm_set.c=230=void omap2xxx_clkt_vps_init(void)\n--\narch/arm/mach-omap2/clkt2xxx_virt_prcm_set.c-239-\narch/arm/mach-omap2/clkt2xxx_virt_prcm_set.c:240:\thw = kzalloc_obj(hw);\narch/arm/mach-omap2/clkt2xxx_virt_prcm_set.c-241-\tif (!hw)\n--\narch/arm/mach-omap2/id.c=786=void __init omap_soc_device_init(void)\n--\narch/arm/mach-omap2/id.c-790-\narch/arm/mach-omap2/id.c:791:\tsoc_dev_attr = kzalloc_obj(soc_dev_attr);\narch/arm/mach-omap2/id.c-792-\tif (!soc_dev_attr)\n--\narch/arm/mach-omap2/omap_device.c=131=static int omap_device_build_from_dt(struct platform_device pdev)\n--\narch/arm/mach-omap2/omap_device.c-158-\narch/arm/mach-omap2/omap_device.c:159:\thwmods = kzalloc_objs(struct omap_hwmod , oh_cnt);\narch/arm/mach-omap2/omap_device.c-160-\tif (!hwmods) {\n--\narch/arm/mach-omap2/omap_hwmod.c=3389=static int omap_hwmod_allocate_module(struct device dev, struct omap_hwmod oh,\n--\narch/arm/mach-omap2/omap_hwmod.c-3402-\narch/arm/mach-omap2/omap_hwmod.c:3403:\tsysc = kzalloc_obj(sysc);\narch/arm/mach-omap2/omap_hwmod.c-3404-\tif (!sysc)\n--\narch/arm/mach-omap2/omap_hwmod.c-3432-\tif (list_empty(\u0026oh-\u003eslave_ports)) {\narch/arm/mach-omap2/omap_hwmod.c:3433:\t\toi = kzalloc_obj(oi);\narch/arm/mach-omap2/omap_hwmod.c-3434-\t\tif (!oi)\n--\narch/arm/mach-omap2/omap_hwmod.c=3521=int omap_hwmod_init_module(struct device dev,\n--\narch/arm/mach-omap2/omap_hwmod.c-3535-\tif (!oh) {\narch/arm/mach-omap2/omap_hwmod.c:3536:\t\toh = kzalloc_obj(oh);\narch/arm/mach-omap2/omap_hwmod.c-3537-\t\tif (!oh)\n--\narch/arm/mach-omap2/omap_hwmod.c-3546-\narch/arm/mach-omap2/omap_hwmod.c:3547:\t\toh-\u003eclass = kzalloc_obj(oh-\u003eclass);\narch/arm/mach-omap2/omap_hwmod.c-3548-\t\tif (!oh-\u003eclass) {\n--\narch/arm/mach-omap2/pm33xx-core.c=379=static int __init amx3_idle_init(struct device_node cpu_node, int cpu)\n--\narch/arm/mach-omap2/pm33xx-core.c-412-\narch/arm/mach-omap2/pm33xx-core.c:413:\tidle_states = kzalloc_objs(idle_states, state_count);\narch/arm/mach-omap2/pm33xx-core.c-414-\tif (!idle_states)\n--\narch/arm/mach-omap2/sr_device.c=30=static void __init sr_set_nvalues(struct omap_volt_data volt_data,\n--\narch/arm/mach-omap2/sr_device.c-41-\narch/arm/mach-omap2/sr_device.c:42:\tnvalue_table = kzalloc_objs(nvalue_table, count);\narch/arm/mach-omap2/sr_device.c-43-\tif (!nvalue_table)\n--\narch/arm/mach-orion5x/pci.c=139=static int __init pcie_setup(struct pci_sys_data sys)\n--\narch/arm/mach-orion5x/pci.c-171-\t /\narch/arm/mach-orion5x/pci.c:172:\tres = kzalloc_obj(struct resource);\narch/arm/mach-orion5x/pci.c-173-\tif (!res)\n--\narch/arm/mach-orion5x/pci.c=466=static int __init pci_setup(struct pci_sys_data sys)\n--\narch/arm/mach-orion5x/pci.c-492-\t /\narch/arm/mach-orion5x/pci.c:493:\tres = kzalloc_obj(struct resource);\narch/arm/mach-orion5x/pci.c-494-\tif (!res)\n--\narch/arm/mach-rpc/ecard.c=689=static struct expansion_card __init ecard_alloc_card(int type, int slot)\n--\narch/arm/mach-rpc/ecard.c-694-\narch/arm/mach-rpc/ecard.c:695:\tec = kzalloc_obj(ecard_t);\narch/arm/mach-rpc/ecard.c-696-\tif (!ec) {\n--\narch/arm/mach-sa1100/clock.c=93=int __init sa11xx_clk_init(void)\n--\narch/arm/mach-sa1100/clock.c-109-\narch/arm/mach-sa1100/clock.c:110:\thw = kzalloc_obj(hw);\narch/arm/mach-sa1100/clock.c-111-\tif (!hw)\n--\narch/arm/mach-sa1100/clock.c-131-\narch/arm/mach-sa1100/clock.c:132:\thw = kzalloc_obj(hw);\narch/arm/mach-sa1100/clock.c-133-\tif (!hw)\n--\narch/arm/mach-sa1100/generic.c=317=int __init sa11x0_register_fixed_regulator(int n,\n--\narch/arm/mach-sa1100/generic.c-323-\narch/arm/mach-sa1100/generic.c:324:\tcfg-\u003einit_data = id = kzalloc_obj(cfg-\u003einit_data);\narch/arm/mach-sa1100/generic.c-325-\tif (!cfg-\u003einit_data)\n--\narch/arm/mach-sa1100/neponset.c=225=static int neponset_probe(struct platform_device dev)\n--\narch/arm/mach-sa1100/neponset.c-278-\narch/arm/mach-sa1100/neponset.c:279:\td = kzalloc_obj(d);\narch/arm/mach-sa1100/neponset.c-280-\tif (!d) {\n--\narch/arm/mach-shmobile/regulator-quirk-rcar-gen2.c=141=static int __init rcar_gen2_regulator_quirk(void)\n--\narch/arm/mach-shmobile/regulator-quirk-rcar-gen2.c-166-\narch/arm/mach-shmobile/regulator-quirk-rcar-gen2.c:167:\t\tquirk = kzalloc_obj(quirk);\narch/arm/mach-shmobile/regulator-quirk-rcar-gen2.c-168-\t\tif (!quirk) {\n--\narch/arm/mach-versatile/spc.c=393=static int ve_spc_populate_opps(uint32_t cluster)\n--\narch/arm/mach-versatile/spc.c-397-\narch/arm/mach-versatile/spc.c:398:\topps = kzalloc_objs(opps, MAX_OPPS);\narch/arm/mach-versatile/spc.c-399-\tif (!opps)\n--\narch/arm/mach-versatile/spc.c=442=int __init ve_spc_init(void __iomem baseaddr, u32 a15_clusid, int irq)\n--\narch/arm/mach-versatile/spc.c-444-\tint ret;\narch/arm/mach-versatile/spc.c:445:\tinfo = kzalloc_obj(info);\narch/arm/mach-versatile/spc.c-446-\tif (!info)\n--\narch/arm/mach-versatile/spc.c=523=static struct clk ve_spc_clk_register(struct device cpu_dev)\n--\narch/arm/mach-versatile/spc.c-527-\narch/arm/mach-versatile/spc.c:528:\tspc = kzalloc_obj(spc);\narch/arm/mach-versatile/spc.c-529-\tif (!spc)\n--\narch/arm/mach-versatile/versatile.c=123=static void __init versatile_dt_pci_init(void)\n--\narch/arm/mach-versatile/versatile.c-144-\narch/arm/mach-versatile/versatile.c:145:\tnewprop = kzalloc_obj(newprop);\narch/arm/mach-versatile/versatile.c-146-\tif (!newprop)\n--\narch/arm/mach-zynq/common.c=105=static void __init zynq_init_machine(void)\n--\narch/arm/mach-zynq/common.c-110-\narch/arm/mach-zynq/common.c:111:\tsoc_dev_attr = kzalloc_obj(soc_dev_attr);\narch/arm/mach-zynq/common.c-112-\tif (!soc_dev_attr)\n--\narch/arm/mm/cache-l2x0-pmu.c=503=static __init int l2x0_pmu_init(void)\n--\narch/arm/mm/cache-l2x0-pmu.c-509-\narch/arm/mm/cache-l2x0-pmu.c:510:\tl2x0_pmu = kzalloc_obj(l2x0_pmu);\narch/arm/mm/cache-l2x0-pmu.c-511-\tif (!l2x0_pmu) {\n--\narch/arm/mm/cache-uniphier.c=315=static int __init __uniphier_cache_init(struct device_node np,\n--\narch/arm/mm/cache-uniphier.c-344-\narch/arm/mm/cache-uniphier.c:345:\tdata = kzalloc_obj(data);\narch/arm/mm/cache-uniphier.c-346-\tif (!data)\n--\narch/arm/mm/dma-mapping.c=533=static void __dma_alloc(struct device dev, size_t size, dma_addr_t handle,\n--\narch/arm/mm/dma-mapping.c-560-\narch/arm/mm/dma-mapping.c:561:\tbuf = kzalloc_obj(buf,\narch/arm/mm/dma-mapping.c-562-\t\t\t gfp \u0026 ~(__GFP_DMA \| __GFP_DMA32 \| __GFP_HIGHMEM));\n--\narch/arm/mm/dma-mapping.c=1487=arm_iommu_create_mapping(struct device dev, dma_addr_t base, u64 size)\n--\narch/arm/mm/dma-mapping.c-1506-\narch/arm/mm/dma-mapping.c:1507:\tmapping = kzalloc_obj(struct dma_iommu_mapping);\narch/arm/mm/dma-mapping.c-1508-\tif (!mapping)\n--\narch/arm/xen/enlighten.c=316=int __init arch_xen_unpopulated_init(struct resource res)\n--\narch/arm/xen/enlighten.c-343-\narch/arm/xen/enlighten.c:344:\tregs = kzalloc_objs(regs, nr_reg);\narch/arm/xen/enlighten.c-345-\tif (!regs) {\n--\narch/arm/xen/enlighten.c-387-\narch/arm/xen/enlighten.c:388:\t\ttmp_res = kzalloc_obj(tmp_res);\narch/arm/xen/enlighten.c-389-\t\tif (!tmp_res) {\n--\narch/arm/xen/p2m.c=150=bool __set_phys_to_machine_multi(unsigned long pfn,\n--\narch/arm/xen/p2m.c-178-\narch/arm/xen/p2m.c:179:\tp2m_entry = kzalloc_obj(p2m_entry, GFP_NOWAIT);\narch/arm/xen/p2m.c-180-\tif (!p2m_entry)\n--\narch/arm64/kernel/vdso.c=68=static int __init __vdso_init(enum vdso_abi abi)\n--\narch/arm64/kernel/vdso.c-83-\narch/arm64/kernel/vdso.c:84:\tvdso_pagelist = kzalloc_objs(struct page , vdso_info[abi].vdso_pages);\narch/arm64/kernel/vdso.c-85-\tif (vdso_pagelist == NULL)\n--\narch/arm64/kvm/mmu.c=480=static int share_pfn_hyp(u64 pfn)\n--\narch/arm64/kvm/mmu.c-492-\narch/arm64/kvm/mmu.c:493:\tthis = kzalloc_obj(this);\narch/arm64/kvm/mmu.c-494-\tif (!this) {\n--\narch/arm64/kvm/mmu.c=981=int kvm_init_stage2_mmu(struct kvm kvm, struct kvm_s2_mmu mmu, unsigned long type)\n--\narch/arm64/kvm/mmu.c-1007-\narch/arm64/kvm/mmu.c:1008:\tpgt = kzalloc_obj(pgt, GFP_KERNEL_ACCOUNT);\narch/arm64/kvm/mmu.c-1009-\tif (!pgt)\n--\narch/arm64/kvm/mmu.c=1180=int topup_hyp_memcache(struct kvm_hyp_memcache mc, unsigned long min_pages)\n--\narch/arm64/kvm/mmu.c-1185-\tif (!mc-\u003emapping) {\narch/arm64/kvm/mmu.c:1186:\t\tmc-\u003emapping = kzalloc_obj(struct pkvm_mapping,\narch/arm64/kvm/mmu.c-1187-\t\t\t\t\t GFP_KERNEL_ACCOUNT);\n--\narch/arm64/kvm/mmu.c=2513=int __init kvm_mmu_init(u32 hyp_va_bits)\n--\narch/arm64/kvm/mmu.c-2546-\narch/arm64/kvm/mmu.c:2547:\thyp_pgtable = kzalloc_obj(hyp_pgtable);\narch/arm64/kvm/mmu.c-2548-\tif (!hyp_pgtable) {\n--\narch/arm64/kvm/nested.c=1382=int kvm_vcpu_allocate_vncr_tlb(struct kvm_vcpu vcpu)\n--\narch/arm64/kvm/nested.c-1387-\tif (!vcpu-\u003earch.vncr_tlb) {\narch/arm64/kvm/nested.c:1388:\t\tstruct vncr_tlb vt = kzalloc_obj(vcpu-\u003earch.vncr_tlb,\narch/arm64/kvm/nested.c-1389-\t\t\t\t\t\t GFP_KERNEL_ACCOUNT);\n--\narch/arm64/kvm/nested.c=1869=int kvm_init_nv_sysregs(struct kvm_vcpu vcpu)\n--\narch/arm64/kvm/nested.c-1878-\narch/arm64/kvm/nested.c:1879:\tkvm-\u003earch.sysreg_masks = kzalloc_obj((kvm-\u003earch.sysreg_masks),\narch/arm64/kvm/nested.c-1880-\t\t\t\t\t GFP_KERNEL_ACCOUNT);\n--\narch/arm64/kvm/ptdump.c=116=static struct kvm_ptdump_guest_state kvm_ptdump_parser_create(struct kvm_s2_mmu mmu)\n--\narch/arm64/kvm/ptdump.c-121-\narch/arm64/kvm/ptdump.c:122:\tst = kzalloc_obj(struct kvm_ptdump_guest_state, GFP_KERNEL_ACCOUNT);\narch/arm64/kvm/ptdump.c-123-\tif (!st)\n--\narch/arm64/kvm/vgic/vgic-init.c=208=static int kvm_vgic_dist_init(struct kvm kvm, unsigned int nr_spis)\n--\narch/arm64/kvm/vgic/vgic-init.c-217-\tdist-\u003eactive_spis = (atomic_t)ATOMIC_INIT(0);\narch/arm64/kvm/vgic/vgic-init.c:218:\tdist-\u003espis = kzalloc_objs(struct vgic_irq, nr_spis, GFP_KERNEL_ACCOUNT);\narch/arm64/kvm/vgic/vgic-init.c-219-\tif (!dist-\u003espis)\n--\narch/arm64/kvm/vgic/vgic-init.c=320=static int vgic_allocate_private_irqs_locked(struct kvm_vcpu vcpu, u32 type)\n--\narch/arm64/kvm/vgic/vgic-init.c-335-\narch/arm64/kvm/vgic/vgic-init.c:336:\tvgic_cpu-\u003eprivate_irqs = kzalloc_objs(struct vgic_irq,\narch/arm64/kvm/vgic/vgic-init.c-337-\t\t\t\t\t num_private_irqs,\n--\narch/arm64/kvm/vgic/vgic-irqfd.c=142=int kvm_vgic_setup_default_irq_routing(struct kvm kvm)\n--\narch/arm64/kvm/vgic/vgic-irqfd.c-148-\narch/arm64/kvm/vgic/vgic-irqfd.c:149:\tentries = kzalloc_objs(entries, nr, GFP_KERNEL_ACCOUNT);\narch/arm64/kvm/vgic/vgic-irqfd.c-150-\tif (!entries)\n--\narch/arm64/kvm/vgic/vgic-its.c=76=static struct vgic_irq vgic_add_lpi(struct kvm kvm, u32 intid,\n--\narch/arm64/kvm/vgic/vgic-its.c-87-\narch/arm64/kvm/vgic/vgic-its.c:88:\tirq = kzalloc_obj(struct vgic_irq, GFP_KERNEL_ACCOUNT);\narch/arm64/kvm/vgic/vgic-its.c-89-\tif (!irq)\n--\narch/arm64/kvm/vgic/vgic-its.c=971=static int vgic_its_alloc_collection(struct vgic_its its,\n--\narch/arm64/kvm/vgic/vgic-its.c-976-\narch/arm64/kvm/vgic/vgic-its.c:977:\tcollection = kzalloc_obj(collection, GFP_KERNEL_ACCOUNT);\narch/arm64/kvm/vgic/vgic-its.c-978-\tif (!collection)\n--\narch/arm64/kvm/vgic/vgic-its.c=1015=static struct its_ite vgic_its_alloc_ite(struct its_device device,\n--\narch/arm64/kvm/vgic/vgic-its.c-1020-\narch/arm64/kvm/vgic/vgic-its.c:1021:\tite = kzalloc_obj(ite, GFP_KERNEL_ACCOUNT);\narch/arm64/kvm/vgic/vgic-its.c-1022-\tif (!ite)\n--\narch/arm64/kvm/vgic/vgic-its.c=1142=static struct its_device vgic_its_alloc_device(struct vgic_its its,\n--\narch/arm64/kvm/vgic/vgic-its.c-1147-\narch/arm64/kvm/vgic/vgic-its.c:1148:\tdevice = kzalloc_obj(device, GFP_KERNEL_ACCOUNT);\narch/arm64/kvm/vgic/vgic-its.c-1149-\tif (!device)\n--\narch/arm64/kvm/vgic/vgic-its.c=1855=static int vgic_its_create(struct kvm_device dev, u32 type)\n--\narch/arm64/kvm/vgic/vgic-its.c-1862-\narch/arm64/kvm/vgic/vgic-its.c:1863:\tits = kzalloc_obj(struct vgic_its, GFP_KERNEL_ACCOUNT);\narch/arm64/kvm/vgic/vgic-its.c-1864-\tif (!its)\n--\narch/arm64/kvm/vgic/vgic-mmio-v3.c=886=static int vgic_v3_alloc_redist_region(struct kvm kvm, uint32_t index,\n--\narch/arm64/kvm/vgic/vgic-mmio-v3.c-931-\narch/arm64/kvm/vgic/vgic-mmio-v3.c:932:\trdreg = kzalloc_obj(rdreg, GFP_KERNEL_ACCOUNT);\narch/arm64/kvm/vgic/vgic-mmio-v3.c-933-\tif (!rdreg)\n--\narch/arm64/kvm/vgic/vgic-v4.c=242=int vgic_v4_init(struct kvm kvm)\n--\narch/arm64/kvm/vgic/vgic-v4.c-258-\narch/arm64/kvm/vgic/vgic-v4.c:259:\tdist-\u003eits_vm.vpes = kzalloc_objs(dist-\u003eits_vm.vpes, nr_vcpus,\narch/arm64/kvm/vgic/vgic-v4.c-260-\t\t\t\t\t GFP_KERNEL_ACCOUNT);\n--\narch/arm64/net/bpf_jit_comp.c=2156=struct bpf_prog bpf_int_jit_compile(struct bpf_verifier_env env, struct bpf_prog prog)\n--\narch/arm64/net/bpf_jit_comp.c-2177-\tif (!jit_data) {\narch/arm64/net/bpf_jit_comp.c:2178:\t\tjit_data = kzalloc_obj(*jit_data);\narch/arm64/net/bpf_jit_comp.c-2179-\t\tif (!jit_data)\n--\narch/csky/kernel/vdso.c=17=static int __init vdso_init(void)\n--\narch/csky/kernel/vdso.c-22-\tvdso_pagelist =\n\n" }
31/3	2026/09/02 19:04	llm	kmsan-evaluator	0m Model: gemini-3.7-flash Args: null Results: null Tokens: input: 17564 output: 46 thoughts: 23 Thoughts: Okay, here's my take on those thoughts, tailored for an expert audience, presented in the first person: Analyzing the Patch's Impact Right, let's dive into this patch. My immediate concern is ensuring this code change doesn't introduce any subtle nasties. I need to meticulously inspect every single file this patch modifies. I'm especially on the lookout for any potential edge cases that might be exposed by these changes. Think about scenarios where unexpected inputs could lead to trouble. I need to be sure this patch handles those gracefully. Beyond edge cases, I’m also extremely wary of the potential for uninitialized memory usage. A careless change here could open the door to all sorts of vulnerabilities, or at the very least, unpredictable behavior. So, my goal is to verify that memory is properly initialized before any read or write operation occurs. I'm going to carefully trace the data flows and logic paths affected by this patch with the sole purpose of confirming there are no new opportunities for subtle, hard-to-debug defects.
32/3	2026/09/02 19:04	tool	read-file	0m Args: { "File": "arch/s390/kvm/s390/intercept.c", "FirstLine": 430, "LineCount": 45 } Results: { "Contents": " 430:\t\tif (reg1 == reg2 \|\| reg1 \u0026 1 \|\| reg2 \u0026 1)\n 431:\t\t\treturn kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);\n 432:\t\n 433:\t\tif (code \u0026 0xffff) {\n 434:\t\t\tcc = 3;\n 435:\t\t\trc = 4;\n 436:\t\t\tgoto out;\n 437:\t\t}\n 438:\t\n 439:\t\tif (!kvm_s390_pv_cpu_is_protected(vcpu) \u0026\u0026 (addr \u0026 ~PAGE_MASK))\n 440:\t\t\treturn kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);\n 441:\t\n 442:\t\tsctns = kzalloc(PAGE_SIZE, GFP_KERNEL_ACCOUNT);\n 443:\t\tif (!sctns)\n 444:\t\t\treturn -ENOMEM;\n 445:\t\n 446:\t\tcc = sthyi_fill(sctns, \u0026rc);\n 447:\t\tif (cc \u003c 0) {\n 448:\t\t\tkfree(sctns);\n 449:\t\t\treturn cc;\n 450:\t\t}\n 451:\tout:\n 452:\t\tif (!cc) {\n 453:\t\t\tif (kvm_s390_pv_cpu_is_protected(vcpu)) {\n 454:\t\t\t\tmemcpy(sida_addr(vcpu-\u003earch.sie_block), sctns, PAGE_SIZE);\n 455:\t\t\t} else {\n 456:\t\t\t\tr = write_guest(vcpu, addr, reg2, sctns, PAGE_SIZE);\n 457:\t\t\t\tif (r) {\n 458:\t\t\t\t\tkfree(sctns);\n 459:\t\t\t\t\treturn kvm_s390_inject_prog_cond(vcpu, r);\n 460:\t\t\t\t}\n 461:\t\t\t}\n 462:\t\t}\n 463:\t\n 464:\t\tkfree(sctns);\n 465:\t\tvcpu-\u003erun-\u003es.regs.gprs[reg2 + 1] = rc;\n 466:\t\tkvm_s390_set_psw_cc(vcpu, cc);\n 467:\t\treturn r;\n 468:\t}\n 469:\t\n 470:\tstatic int handle_operexc(struct kvm_vcpu *vcpu)\n 471:\t{\n 472:\t\tpsw_t oldpsw, newpsw;\n 473:\t\tint rc;\n 474:\t\n" }
33/3	2026/09/02 19:04	llm	kmsan-evaluator	0m Model: gemini-3.7-flash Args: null Results: null Tokens: input: 18561 output: 46 thoughts: 24 Thoughts: Here's my attempt at summarizing the thought process, tailored for an expert audience and written in the first person: Diving into `arch/s390/kvm/s390/priv.c` Okay, I need to get my bearings on this specific area of the s390 KVM implementation. Time to take a look at `arch/s390/kvm/s390/priv.c`. This file almost certainly deals with privileged instruction handling and potentially the interface between the guest and the host for those types of operations, given the name. I'm expecting to see definitions for things like the hypercall interfaces, any emulated instructions that need special treatment, and possibly the structures used to represent the guest's privileged state that KVM needs to manage. I'm thinking I'll be looking for things like handlers for DIAG instruction interception, PSW manipulation within the virtual machine, and any code related to virtualization of control registers. I'll need to pay close attention to the lock usage within this file, especially if there are any race conditions that might be exploitable when dealing with sensitive operations. My first pass will likely be high level to get the structure of the file, then I'll drill down to any specific areas that look interesting to me.
34/3	2026/09/02 19:04	tool	read-file	0m Args: { "File": "arch/s390/kvm/s390/priv.c", "FirstLine": 905, "LineCount": 55 } Results: { "Contents": " 905:\t\t}\n 906:\t\n 907:\t\toperand2 = kvm_s390_get_base_disp_s(vcpu, \u0026ar);\n 908:\t\n 909:\t\tif (!kvm_s390_pv_cpu_is_protected(vcpu) \u0026\u0026 (operand2 \u0026 0xfff))\n 910:\t\t\treturn kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);\n 911:\t\n 912:\t\tswitch (fc) {\n 913:\t\tcase 1: /* same handling for 1 and 2 /\n 914:\t\tcase 2:\n 915:\t\t\tmem = kzalloc(PAGE_SIZE, GFP_KERNEL_ACCOUNT);\n 916:\t\t\tif (!mem)\n 917:\t\t\t\tgoto out_no_data;\n 918:\t\t\tif (stsi(mem, fc, sel1, sel2))\n 919:\t\t\t\tgoto out_no_data;\n 920:\t\t\tbreak;\n 921:\t\tcase 3:\n 922:\t\t\tif (sel1 != 2 \|\| sel2 != 2)\n 923:\t\t\t\tgoto out_no_data;\n 924:\t\t\tmem = kzalloc(PAGE_SIZE, GFP_KERNEL_ACCOUNT);\n 925:\t\t\tif (!mem)\n 926:\t\t\t\tgoto out_no_data;\n 927:\t\t\thandle_stsi_3_2_2(vcpu, mem);\n 928:\t\t\tbreak;\n 929:\t\tcase 15: / fc 15 is fully handled in userspace */\n 930:\t\t\tinsert_stsi_usr_data(vcpu, operand2, ar, fc, sel1, sel2);\n 931:\t\t\ttrace_kvm_s390_handle_stsi(vcpu, fc, sel1, sel2, operand2);\n 932:\t\t\treturn -EREMOTE;\n 933:\t\t}\n 934:\t\tif (kvm_s390_pv_cpu_is_protected(vcpu)) {\n 935:\t\t\tmemcpy(sida_addr(vcpu-\u003earch.sie_block), mem, PAGE_SIZE);\n 936:\t\t\trc = 0;\n 937:\t\t} else {\n 938:\t\t\trc = write_guest(vcpu, operand2, ar, mem, PAGE_SIZE);\n 939:\t\t}\n 940:\t\tif (rc) {\n 941:\t\t\trc = kvm_s390_inject_prog_cond(vcpu, rc);\n 942:\t\t\tgoto out;\n 943:\t\t}\n 944:\t\tif (vcpu-\u003ekvm-\u003earch.user_stsi) {\n 945:\t\t\tinsert_stsi_usr_data(vcpu, operand2, ar, fc, sel1, sel2);\n 946:\t\t\trc = -EREMOTE;\n 947:\t\t}\n 948:\t\ttrace_kvm_s390_handle_stsi(vcpu, fc, sel1, sel2, operand2);\n 949:\t\tkfree(mem);\n 950:\t\tkvm_s390_set_psw_cc(vcpu, 0);\n 951:\t\tvcpu-\u003erun-\u003es.regs.gprs[0] = 0;\n 952:\t\treturn rc;\n 953:\tout_no_data:\n 954:\t\tkvm_s390_set_psw_cc(vcpu, 3);\n 955:\tout:\n 956:\t\tkfree(mem);\n 957:\t\treturn rc;\n 958:\t}\n 959:\t\n" }
35/3	2026/09/02 19:04	llm	kmsan-evaluator	0m Model: gemini-3.7-flash Args: null Results: null Tokens: input: 19869 output: 50 thoughts: 33 Thoughts: Here's my analysis of the situation, presented from my perspective as an expert: Investigating KVM/s390 Interrupt Handling Okay, so we're diving into the heart of the KVM/s390 interaction, specifically regarding interrupts. My first instinct, given the context, is to zero in on two key files: `arch/s390/kvm/s390/s390.c` and `interrupt.c`. `s390.c` is the likely place where core s390-specific KVM setup and functionality reside, and within that, the connection to interrupt handling will be vital. Conversely, interrupt.c is where low level interrupt functions are. Now I suspect these will provide the critical pieces of the puzzle. I expect to find the interrupt vectoring, the interrupt injection mechanisms, and the crucial interactions between the guest's view of interrupts and the host's handling of them defined in these areas. I need to understand how the hardware interrupts are mapped to guest interrupts within the KVM environment, and that will be a good starting point. Let's see what's in these files...
36/3	2026/09/02 19:04	tool	read-file	0m Args: { "File": "arch/s390/kvm/s390/s390.c", "FirstLine": 3270, "LineCount": 40 } Results: { "Contents": "3270:\t\n3271:\t\tkvm-\u003earch.dbf = debug_register(debug_name, 32, 1, 7 * sizeof(long));\n3272:\t\tif (!kvm-\u003earch.dbf)\n3273:\t\t\tgoto out_err;\n3274:\t\n3275:\t\tBUILD_BUG_ON(sizeof(struct sie_page2) != 4096);\n3276:\t\tkvm-\u003earch.sie_page2 = kzalloc_obj(kvm-\u003earch.sie_page2,\n3277:\t\t\t\t\t\t GFP_KERNEL_ACCOUNT \| GFP_DMA);\n3278:\t\tif (!kvm-\u003earch.sie_page2)\n3279:\t\t\tgoto out_err;\n3280:\t\n3281:\t\tkvm-\u003earch.sie_page2-\u003ekvm = kvm;\n3282:\t\tkvm-\u003earch.model.fac_list = kvm-\u003earch.sie_page2-\u003efac_list;\n3283:\t\n3284:\t\tfor (i = 0; i \u003c ARRAY_SIZE(kvm_s390_fac_base); i++) {\n3285:\t\t\tkvm-\u003earch.model.fac_mask[i] = stfle_fac_list[i] \u0026\n3286:\t\t\t\t\t\t kvm_s390_fac_base[i];\n3287:\t\t\tkvm-\u003earch.model.fac_list[i] = stfle_fac_list[i] \u0026\n3288:\t\t\t\t\t\t kvm_s390_fac_base[i];\n3289:\t\t}\n3290:\t\tfor (i = 0; i \u003c ARRAY_SIZE(kvm_s390_fac_ext); i++) {\n3291:\t\t\tkvm-\u003earch.model.fac_mask[i] \|= stfle_fac_list[i] \u0026\n3292:\t\t\t\t\t\t kvm_s390_fac_ext[i];\n3293:\t\t}\n3294:\t\tkvm-\u003earch.model.subfuncs = kvm_s390_available_subfunc;\n3295:\t\n3296:\t\t/ we are always in czam mode - even on pre z14 machines /\n3297:\t\tset_kvm_facility(kvm-\u003earch.model.fac_mask, 138);\n3298:\t\tset_kvm_facility(kvm-\u003earch.model.fac_list, 138);\n3299:\t\t/ we emulate STHYI in kvm */\n3300:\t\tset_kvm_facility(kvm-\u003earch.model.fac_mask, 74);\n3301:\t\tset_kvm_facility(kvm-\u003earch.model.fac_list, 74);\n3302:\t\tif (machine_has_tlb_guest()) {\n3303:\t\t\tset_kvm_facility(kvm-\u003earch.model.fac_mask, 147);\n3304:\t\t\tset_kvm_facility(kvm-\u003earch.model.fac_list, 147);\n3305:\t\t}\n3306:\t\n3307:\t\tif (css_general_characteristics.aiv \u0026\u0026 test_facility(65))\n3308:\t\t\tset_kvm_facility(kvm-\u003earch.model.fac_mask, 65);\n3309:\t\n" }
37/3	2026/09/02 19:04	llm	kmsan-evaluator	0m Model: gemini-3.7-flash Args: null Results: null Tokens: input: 21067 output: 192 thoughts: 268 Thoughts: KMSAN Assessment: No New Risks Detected Okay, so this patch is a straightforward swap-out, replacing the old `get_zeroed_page` and `free_page` functions with the newer `kzalloc` (or `kzalloc_obj`) and `kfree` in the s390 KVM subsystem. The critical thing here is that the zero-initialization is maintained. Every single place the old code was allocating zeroed pages, the new code is also allocating zeroed memory through `kzalloc`. This is key. There's absolutely no evidence of introducing any uninitialized memory whatsoever. No new paths are created that could potentially lead to the use of uninitialized data, and, critically, no user-space leaks are enabled. We're keeping things clean. Given these points, my conclusion is that we absolutely do not need a dedicated KMSAN fuzzing session for this change. The replacement of page allocations with slab allocations, while a different mechanism, maintains the crucial zero-initialization, which is what KMSAN would be particularly concerned about. Any memory management issues from the slab conversions would be caught by KASAN anyway. I'm ready to mark this as KMSAN-clean. Let's invoke `set-results`.
38/3	2026/09/02 19:04	tool	set-results	0m Args: { "KMSANReasoning": "The patch converts page allocations via get_zeroed_page() and free_page() to slab allocations via kzalloc()/kzalloc_obj() and kfree() across s390 KVM code (intercept.c, interrupt.c, priv.c, s390.c). \n\nSince kzalloc/kzalloc_obj zero-initializes the memory identically to get_zeroed_page(), no uninitialized memory usage, conditional branches on uninitialized data, or uninitialized info-leaks to userspace/guest are introduced. Any potential slab-related memory safety issues (e.g. out-of-bounds, use-after-free, or double-free) are monitored by standard KASAN. Thus, a dedicated KMSAN fuzzing session is not required.", "NeedsKMSAN": false } Results: { "KMSANReasoning": "The patch converts page allocations via get_zeroed_page() and free_page() to slab allocations via kzalloc()/kzalloc_obj() and kfree() across s390 KVM code (intercept.c, interrupt.c, priv.c, s390.c). \n\nSince kzalloc/kzalloc_obj zero-initializes the memory identically to get_zeroed_page(), no uninitialized memory usage, conditional branches on uninitialized data, or uninitialized info-leaks to userspace/guest are introduced. Any potential slab-related memory safety issues (e.g. out-of-bounds, use-after-free, or double-free) are monitored by standard KASAN. Thus, a dedicated KMSAN fuzzing session is not required.", "NeedsKMSAN": false }

{
  "EnableConfigs": [
    "KVM",
    "VIRTUALIZATION"
  ],
  "FocusSymbols": [
    "handle_sthyi",
    "kvm_s390_handle_b2",
    "kvm_arch_init_vm",
    "kvm_s390_vcpu_setup_cmma"
  ],
  "KMSANReasoning": "The patch converts page allocations via get_zeroed_page() and free_page() to slab allocations via kzalloc()/kzalloc_obj() and kfree() across s390 KVM code (intercept.c, interrupt.c, priv.c, s390.c). \n\nSince kzalloc/kzalloc_obj zero-initializes the memory identically to get_zeroed_page(), no uninitialized memory usage, conditional branches on uninitialized data, or uninitialized info-leaks to userspace/guest are introduced. Any potential slab-related memory safety issues (e.g. out-of-bounds, use-after-free, or double-free) are monitored by standard KASAN. Thus, a dedicated KMSAN fuzzing session is not required.",
  "NeedsKMSAN": false,
  "Reasoning": "The patch changes page-level memory allocations (get_zeroed_page/free_page) to slab allocations (kzalloc/kfree) in KVM on s390 for guest intercept handling (STHYI, STSI), VM initialization (sie_page2), GIB setup, and VCPU CMMA setup. These affect reachable KVM execution paths and memory management on s390, making it worth fuzzing.",
  "WorthFuzzing": true
}

{
  "PatchDiff": "commit d6dfce07c89aeb7d6cbdec8c5ab5c85f2699366d\nAuthor: syz-cluster \u003ctriage@syzkaller.com\u003e\nDate:   Wed Sep 2 19:02:54 2026 +0000\n\n    syz-cluster: applied patch under review\n\ndiff --git a/arch/s390/kvm/s390/intercept.c b/arch/s390/kvm/s390/intercept.c\nindex ca1205dfac8b0..aaf9828d1f44d 100644\n--- a/arch/s390/kvm/s390/intercept.c\n+++ b/arch/s390/kvm/s390/intercept.c\n@@ -11,6 +11,7 @@\n #include \u003clinux/kvm_host.h\u003e\n #include \u003clinux/errno.h\u003e\n #include \u003clinux/pagemap.h\u003e\n+#include \u003clinux/slab.h\u003e\n \n #include \u003casm/asm-offsets.h\u003e\n #include \u003casm/irq.h\u003e\n@@ -438,13 +439,13 @@ int handle_sthyi(struct kvm_vcpu *vcpu)\n \tif (!kvm_s390_pv_cpu_is_protected(vcpu) \u0026\u0026 (addr \u0026 ~PAGE_MASK))\n \t\treturn kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);\n \n-\tsctns = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT);\n+\tsctns = kzalloc(PAGE_SIZE, GFP_KERNEL_ACCOUNT);\n \tif (!sctns)\n \t\treturn -ENOMEM;\n \n \tcc = sthyi_fill(sctns, \u0026rc);\n \tif (cc \u003c 0) {\n-\t\tfree_page((unsigned long)sctns);\n+\t\tkfree(sctns);\n \t\treturn cc;\n \t}\n out:\n@@ -454,13 +455,13 @@ int handle_sthyi(struct kvm_vcpu *vcpu)\n \t\t} else {\n \t\t\tr = write_guest(vcpu, addr, reg2, sctns, PAGE_SIZE);\n \t\t\tif (r) {\n-\t\t\t\tfree_page((unsigned long)sctns);\n+\t\t\t\tkfree(sctns);\n \t\t\t\treturn kvm_s390_inject_prog_cond(vcpu, r);\n \t\t\t}\n \t\t}\n \t}\n \n-\tfree_page((unsigned long)sctns);\n+\tkfree(sctns);\n \tvcpu-\u003erun-\u003es.regs.gprs[reg2 + 1] = rc;\n \tkvm_s390_set_psw_cc(vcpu, cc);\n \treturn r;\ndiff --git a/arch/s390/kvm/s390/interrupt.c b/arch/s390/kvm/s390/interrupt.c\nindex 0381ae9817035..02065fb8d053e 100644\n--- a/arch/s390/kvm/s390/interrupt.c\n+++ b/arch/s390/kvm/s390/interrupt.c\n@@ -3689,7 +3689,7 @@ void kvm_s390_gib_destroy(void)\n \t}\n \tchsc_sgib(0);\n \tunregister_adapter_interrupt(\u0026gib_alert_irq);\n-\tfree_page((unsigned long)gib);\n+\tkfree(gib);\n \tgib = NULL;\n }\n \n@@ -3703,7 +3703,7 @@ int __init kvm_s390_gib_init(u8 nisc)\n \t\tgoto out;\n \t}\n \n-\tgib = (struct kvm_s390_gib *)get_zeroed_page(GFP_KERNEL_ACCOUNT | GFP_DMA);\n+\tgib = kzalloc(PAGE_SIZE, GFP_KERNEL_ACCOUNT | GFP_DMA);\n \tif (!gib) {\n \t\trc = -ENOMEM;\n \t\tgoto out;\n@@ -3722,7 +3722,7 @@ int __init kvm_s390_gib_init(u8 nisc)\n \tgib_origin = virt_to_phys(gib);\n \tif (chsc_sgib(gib_origin)) {\n \t\tpr_err(\"Associating the GIB with the AIV facility failed\\n\");\n-\t\tfree_page((unsigned long)gib);\n+\t\tkfree(gib);\n \t\tgib = NULL;\n \t\trc = -EIO;\n \t\tgoto out_unreg_gal;\n@@ -3742,7 +3742,7 @@ int __init kvm_s390_gib_init(u8 nisc)\n out_unreg_gal:\n \tunregister_adapter_interrupt(\u0026gib_alert_irq);\n out_free_gib:\n-\tfree_page((unsigned long)gib);\n+\tkfree(gib);\n \tgib = NULL;\n out:\n \treturn rc;\ndiff --git a/arch/s390/kvm/s390/priv.c b/arch/s390/kvm/s390/priv.c\nindex b3cb2c2c3aa71..856939acf012f 100644\n--- a/arch/s390/kvm/s390/priv.c\n+++ b/arch/s390/kvm/s390/priv.c\n@@ -14,6 +14,7 @@\n #include \u003clinux/mm_types.h\u003e\n #include \u003clinux/pgtable.h\u003e\n #include \u003clinux/io.h\u003e\n+#include \u003clinux/slab.h\u003e\n #include \u003casm/asm-offsets.h\u003e\n #include \u003casm/facility.h\u003e\n #include \u003casm/current.h\u003e\n@@ -869,7 +870,7 @@ static int handle_stsi(struct kvm_vcpu *vcpu)\n \tint fc = (vcpu-\u003erun-\u003es.regs.gprs[0] \u0026 0xf0000000) \u003e\u003e 28;\n \tint sel1 = vcpu-\u003erun-\u003es.regs.gprs[0] \u0026 0xff;\n \tint sel2 = vcpu-\u003erun-\u003es.regs.gprs[1] \u0026 0xffff;\n-\tunsigned long mem = 0;\n+\tvoid *mem = NULL;\n \tu64 operand2;\n \tint rc = 0;\n \tu8 ar;\n@@ -911,19 +912,19 @@ static int handle_stsi(struct kvm_vcpu *vcpu)\n \tswitch (fc) {\n \tcase 1: /* same handling for 1 and 2 */\n \tcase 2:\n-\t\tmem = get_zeroed_page(GFP_KERNEL_ACCOUNT);\n+\t\tmem = kzalloc(PAGE_SIZE, GFP_KERNEL_ACCOUNT);\n \t\tif (!mem)\n \t\t\tgoto out_no_data;\n-\t\tif (stsi((void *) mem, fc, sel1, sel2))\n+\t\tif (stsi(mem, fc, sel1, sel2))\n \t\t\tgoto out_no_data;\n \t\tbreak;\n \tcase 3:\n \t\tif (sel1 != 2 || sel2 != 2)\n \t\t\tgoto out_no_data;\n-\t\tmem = get_zeroed_page(GFP_KERNEL_ACCOUNT);\n+\t\tmem = kzalloc(PAGE_SIZE, GFP_KERNEL_ACCOUNT);\n \t\tif (!mem)\n \t\t\tgoto out_no_data;\n-\t\thandle_stsi_3_2_2(vcpu, (void *) mem);\n+\t\thandle_stsi_3_2_2(vcpu, mem);\n \t\tbreak;\n \tcase 15: /* fc 15 is fully handled in userspace */\n \t\tinsert_stsi_usr_data(vcpu, operand2, ar, fc, sel1, sel2);\n@@ -931,10 +932,10 @@ static int handle_stsi(struct kvm_vcpu *vcpu)\n \t\treturn -EREMOTE;\n \t}\n \tif (kvm_s390_pv_cpu_is_protected(vcpu)) {\n-\t\tmemcpy(sida_addr(vcpu-\u003earch.sie_block), (void *)mem, PAGE_SIZE);\n+\t\tmemcpy(sida_addr(vcpu-\u003earch.sie_block), mem, PAGE_SIZE);\n \t\trc = 0;\n \t} else {\n-\t\trc = write_guest(vcpu, operand2, ar, (void *)mem, PAGE_SIZE);\n+\t\trc = write_guest(vcpu, operand2, ar, mem, PAGE_SIZE);\n \t}\n \tif (rc) {\n \t\trc = kvm_s390_inject_prog_cond(vcpu, rc);\n@@ -945,14 +946,14 @@ static int handle_stsi(struct kvm_vcpu *vcpu)\n \t\trc = -EREMOTE;\n \t}\n \ttrace_kvm_s390_handle_stsi(vcpu, fc, sel1, sel2, operand2);\n-\tfree_page(mem);\n+\tkfree(mem);\n \tkvm_s390_set_psw_cc(vcpu, 0);\n \tvcpu-\u003erun-\u003es.regs.gprs[0] = 0;\n \treturn rc;\n out_no_data:\n \tkvm_s390_set_psw_cc(vcpu, 3);\n out:\n-\tfree_page(mem);\n+\tkfree(mem);\n \treturn rc;\n }\n \ndiff --git a/arch/s390/kvm/s390/s390.c b/arch/s390/kvm/s390/s390.c\nindex b0839e887221e..8ec505060f8c0 100644\n--- a/arch/s390/kvm/s390/s390.c\n+++ b/arch/s390/kvm/s390/s390.c\n@@ -3273,8 +3273,8 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)\n \t\tgoto out_err;\n \n \tBUILD_BUG_ON(sizeof(struct sie_page2) != 4096);\n-\tkvm-\u003earch.sie_page2 =\n-\t     (struct sie_page2 *) get_zeroed_page(GFP_KERNEL_ACCOUNT | GFP_DMA);\n+\tkvm-\u003earch.sie_page2 = kzalloc_obj(*kvm-\u003earch.sie_page2,\n+\t\t\t\t\t  GFP_KERNEL_ACCOUNT | GFP_DMA);\n \tif (!kvm-\u003earch.sie_page2)\n \t\tgoto out_err;\n \n@@ -3369,7 +3369,7 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)\n \n \treturn 0;\n out_err:\n-\tfree_page((unsigned long)kvm-\u003earch.sie_page2);\n+\tkfree(kvm-\u003earch.sie_page2);\n \tdebug_unregister(kvm-\u003earch.dbf);\n \tsca_dispose(kvm);\n \tKVM_EVENT(3, \"creation of vm failed: %d\", rc);\n@@ -3427,7 +3427,7 @@ void kvm_arch_destroy_vm(struct kvm *kvm)\n \t\tmmu_notifier_unregister(\u0026kvm-\u003earch.pv.mmu_notifier, kvm-\u003emm);\n \n \tdebug_unregister(kvm-\u003earch.dbf);\n-\tfree_page((unsigned long)kvm-\u003earch.sie_page2);\n+\tkfree(kvm-\u003earch.sie_page2);\n \tkvm_s390_destroy_adapters(kvm);\n \tkvm_s390_clear_float_irqs(kvm);\n \tkvm_s390_vsie_destroy(kvm);\n@@ -3657,13 +3657,13 @@ static void kvm_s390_vcpu_crypto_setup(struct kvm_vcpu *vcpu)\n void kvm_s390_vcpu_unsetup_cmma(struct kvm_vcpu *vcpu)\n {\n \tif (vcpu-\u003earch.sie_block-\u003ecbrlo)\n-\t\tfree_page((unsigned long)phys_to_virt(vcpu-\u003earch.sie_block-\u003ecbrlo));\n+\t\tkfree(phys_to_virt(vcpu-\u003earch.sie_block-\u003ecbrlo));\n \tvcpu-\u003earch.sie_block-\u003ecbrlo = 0;\n }\n \n int kvm_s390_vcpu_setup_cmma(struct kvm_vcpu *vcpu)\n {\n-\tvoid *cbrlo_page = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT);\n+\tvoid *cbrlo_page = kzalloc(PAGE_SIZE, GFP_KERNEL_ACCOUNT);\n \n \tif (!cbrlo_page)\n \t\treturn -ENOMEM;\n"
}

{
  "EnableConfigs": [
    "KVM",
    "VIRTUALIZATION"
  ],
  "FocusSymbols": [
    "handle_sthyi",
    "kvm_s390_handle_b2",
    "kvm_arch_init_vm",
    "kvm_s390_vcpu_setup_cmma"
  ],
  "Reasoning": "The patch changes page-level memory allocations (get_zeroed_page/free_page) to slab allocations (kzalloc/kfree) in KVM on s390 for guest intercept handling (STHYI, STSI), VM initialization (sie_page2), GIB setup, and VCPU CMMA setup. These affect reachable KVM execution paths and memory management on s390, making it worth fuzzing.",
  "WorthFuzzing": true
}

You are an expert Linux kernel maintainer.
Your job is to review a provided patch series and determine
if it makes functional changes to the kernel that should be fuzzed.

IMPORTANT: The changes have ALREADY been applied and committed as the HEAD commit in
your workspace. Do NOT rely on your internal knowledge of the kernel. You must actively
use your code access tools to examine the actual source code and confirm any assumptions.

Return WorthFuzzing=false if the patch only contains:
- Modifications to Documentation/, Kconfig files, or code comments.
- Purely decorative changes, such as logging (e.g., pr_err, printk) or tracepoints.
- Changes to numeric constants or macros that do not functionally alter execution flow.
- Code paths that are impossible to reach in virtualized environments like GCE or QEMU,
  even when utilizing software-emulated hardware (e.g., usb gadget, mac80211_hwsim).
- Code in vendor-specific PCIe switch, SmartNIC, or GPU drivers (e.g., mlxsw, pds_core, qed,
  ionic, amdgpu) that require physical PCIe hardware cards not emulated in standard QEMU.
- Driver .remove, .shutdown, or pci_unregister_driver teardown callbacks (e.g., igb_remove)
  that are executed only during PCI hot-unplug or sysfs driver unbind operations.

If it modifies reachable core kernel logic, drivers, or architectures, use your code search
tools to verify the code can be executed, then return WorthFuzzing=true.

When returning WorthFuzzing=true, you MUST ALSO:
1. Extract any specific kernel functions that should be heavily fuzzed into FocusSymbols.
   Avoid listing generic hot-path functions to prevent skewed test distributions.
   Prefer non-static, non-inlined API entrypoint functions over internal static helper functions
   (which are inlined by the compiler and do not have distinct symbol addresses).
2. Identify any specific CONFIG_ options required to properly test this new/modified feature.
   Go and look into the Kconfig files and check for ifdefs around the code, do not make assumptions.
   Also check "depends on" lines in Kconfig to include any non-standard parent subsystem configs
   needed for Kbuild to compile the code statically into vmlinux. List them in the EnableConfigs
   output array, and DO NOT add a 'CONFIG_' prefix (e.g., return "NET_IPV4" instead of "CONFIG_NET_IPV4").
Prefer calling several tools at the same time to save round-trips.


Use set-results tool to provide results of the analysis.
It must be called exactly once before the final reply.
Ignore results of this tool.

For your convenience, here is the diff of the changes:
commit d6dfce07c89aeb7d6cbdec8c5ab5c85f2699366d
Author: syz-cluster <triage@syzkaller.com>
Date:   Wed Sep 2 19:02:54 2026 +0000

    syz-cluster: applied patch under review

diff --git a/arch/s390/kvm/s390/intercept.c b/arch/s390/kvm/s390/intercept.c
index ca1205dfac8b0..aaf9828d1f44d 100644
--- a/arch/s390/kvm/s390/intercept.c
+++ b/arch/s390/kvm/s390/intercept.c
@@ -11,6 +11,7 @@
 #include <linux/kvm_host.h>
 #include <linux/errno.h>
 #include <linux/pagemap.h>
+#include <linux/slab.h>
 
 #include <asm/asm-offsets.h>
 #include <asm/irq.h>
@@ -438,13 +439,13 @@ int handle_sthyi(struct kvm_vcpu *vcpu)
 	if (!kvm_s390_pv_cpu_is_protected(vcpu) && (addr & ~PAGE_MASK))
 		return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
 
-	sctns = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT);
+	sctns = kzalloc(PAGE_SIZE, GFP_KERNEL_ACCOUNT);
 	if (!sctns)
 		return -ENOMEM;
 
 	cc = sthyi_fill(sctns, &rc);
 	if (cc < 0) {
-		free_page((unsigned long)sctns);
+		kfree(sctns);
 		return cc;
 	}
 out:
@@ -454,13 +455,13 @@ int handle_sthyi(struct kvm_vcpu *vcpu)
 		} else {
 			r = write_guest(vcpu, addr, reg2, sctns, PAGE_SIZE);
 			if (r) {
-				free_page((unsigned long)sctns);
+				kfree(sctns);
 				return kvm_s390_inject_prog_cond(vcpu, r);
 			}
 		}
 	}
 
-	free_page((unsigned long)sctns);
+	kfree(sctns);
 	vcpu->run->s.regs.gprs[reg2 + 1] = rc;
 	kvm_s390_set_psw_cc(vcpu, cc);
 	return r;
diff --git a/arch/s390/kvm/s390/interrupt.c b/arch/s390/kvm/s390/interrupt.c
index 0381ae9817035..02065fb8d053e 100644
--- a/arch/s390/kvm/s390/interrupt.c
+++ b/arch/s390/kvm/s390/interrupt.c
@@ -3689,7 +3689,7 @@ void kvm_s390_gib_destroy(void)
 	}
 	chsc_sgib(0);
 	unregister_adapter_interrupt(&gib_alert_irq);
-	free_page((unsigned long)gib);
+	kfree(gib);
 	gib = NULL;
 }
 
@@ -3703,7 +3703,7 @@ int __init kvm_s390_gib_init(u8 nisc)
 		goto out;
 	}
 
-	gib = (struct kvm_s390_gib *)get_zeroed_page(GFP_KERNEL_ACCOUNT | GFP_DMA);
+	gib = kzalloc(PAGE_SIZE, GFP_KERNEL_ACCOUNT | GFP_DMA);
 	if (!gib) {
 		rc = -ENOMEM;
 		goto out;
@@ -3722,7 +3722,7 @@ int __init kvm_s390_gib_init(u8 nisc)
 	gib_origin = virt_to_phys(gib);
 	if (chsc_sgib(gib_origin)) {
 		pr_err("Associating the GIB with the AIV facility failed\n");
-		free_page((unsigned long)gib);
+		kfree(gib);
 		gib = NULL;
 		rc = -EIO;
 		goto out_unreg_gal;
@@ -3742,7 +3742,7 @@ int __init kvm_s390_gib_init(u8 nisc)
 out_unreg_gal:
 	unregister_adapter_interrupt(&gib_alert_irq);
 out_free_gib:
-	free_page((unsigned long)gib);
+	kfree(gib);
 	gib = NULL;
 out:
 	return rc;
diff --git a/arch/s390/kvm/s390/priv.c b/arch/s390/kvm/s390/priv.c
index b3cb2c2c3aa71..856939acf012f 100644
--- a/arch/s390/kvm/s390/priv.c
+++ b/arch/s390/kvm/s390/priv.c
@@ -14,6 +14,7 @@
 #include <linux/mm_types.h>
 #include <linux/pgtable.h>
 #include <linux/io.h>
+#include <linux/slab.h>
 #include <asm/asm-offsets.h>
 #include <asm/facility.h>
 #include <asm/current.h>
@@ -869,7 +870,7 @@ static int handle_stsi(struct kvm_vcpu *vcpu)
 	int fc = (vcpu->run->s.regs.gprs[0] & 0xf0000000) >> 28;
 	int sel1 = vcpu->run->s.regs.gprs[0] & 0xff;
 	int sel2 = vcpu->run->s.regs.gprs[1] & 0xffff;
-	unsigned long mem = 0;
+	void *mem = NULL;
 	u64 operand2;
 	int rc = 0;
 	u8 ar;
@@ -911,19 +912,19 @@ static int handle_stsi(struct kvm_vcpu *vcpu)
 	switch (fc) {
 	case 1: /* same handling for 1 and 2 */
 	case 2:
-		mem = get_zeroed_page(GFP_KERNEL_ACCOUNT);
+		mem = kzalloc(PAGE_SIZE, GFP_KERNEL_ACCOUNT);
 		if (!mem)
 			goto out_no_data;
-		if (stsi((void *) mem, fc, sel1, sel2))
+		if (stsi(mem, fc, sel1, sel2))
 			goto out_no_data;
 		break;
 	case 3:
 		if (sel1 != 2 || sel2 != 2)
 			goto out_no_data;
-		mem = get_zeroed_page(GFP_KERNEL_ACCOUNT);
+		mem = kzalloc(PAGE_SIZE, GFP_KERNEL_ACCOUNT);
 		if (!mem)
 			goto out_no_data;
-		handle_stsi_3_2_2(vcpu, (void *) mem);
+		handle_stsi_3_2_2(vcpu, mem);
 		break;
 	case 15: /* fc 15 is fully handled in userspace */
 		insert_stsi_usr_data(vcpu, operand2, ar, fc, sel1, sel2);
@@ -931,10 +932,10 @@ static int handle_stsi(struct kvm_vcpu *vcpu)
 		return -EREMOTE;
 	}
 	if (kvm_s390_pv_cpu_is_protected(vcpu)) {
-		memcpy(sida_addr(vcpu->arch.sie_block), (void *)mem, PAGE_SIZE);
+		memcpy(sida_addr(vcpu->arch.sie_block), mem, PAGE_SIZE);
 		rc = 0;
 	} else {
-		rc = write_guest(vcpu, operand2, ar, (void *)mem, PAGE_SIZE);
+		rc = write_guest(vcpu, operand2, ar, mem, PAGE_SIZE);
 	}
 	if (rc) {
 		rc = kvm_s390_inject_prog_cond(vcpu, rc);
@@ -945,14 +946,14 @@ static int handle_stsi(struct kvm_vcpu *vcpu)
 		rc = -EREMOTE;
 	}
 	trace_kvm_s390_handle_stsi(vcpu, fc, sel1, sel2, operand2);
-	free_page(mem);
+	kfree(mem);
 	kvm_s390_set_psw_cc(vcpu, 0);
 	vcpu->run->s.regs.gprs[0] = 0;
 	return rc;
 out_no_data:
 	kvm_s390_set_psw_cc(vcpu, 3);
 out:
-	free_page(mem);
+	kfree(mem);
 	return rc;
 }
 
diff --git a/arch/s390/kvm/s390/s390.c b/arch/s390/kvm/s390/s390.c
index b0839e887221e..8ec505060f8c0 100644
--- a/arch/s390/kvm/s390/s390.c
+++ b/arch/s390/kvm/s390/s390.c
@@ -3273,8 +3273,8 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
 		goto out_err;
 
 	BUILD_BUG_ON(sizeof(struct sie_page2) != 4096);
-	kvm->arch.sie_page2 =
-	     (struct sie_page2 *) get_zeroed_page(GFP_KERNEL_ACCOUNT | GFP_DMA);
+	kvm->arch.sie_page2 = kzalloc_obj(*kvm->arch.sie_page2,
+					  GFP_KERNEL_ACCOUNT | GFP_DMA);
 	if (!kvm->arch.sie_page2)
 		goto out_err;
 
@@ -3369,7 +3369,7 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
 
 	return 0;
 out_err:
-	free_page((unsigned long)kvm->arch.sie_page2);
+	kfree(kvm->arch.sie_page2);
 	debug_unregister(kvm->arch.dbf);
 	sca_dispose(kvm);
 	KVM_EVENT(3, "creation of vm failed: %d", rc);
@@ -3427,7 +3427,7 @@ void kvm_arch_destroy_vm(struct kvm *kvm)
 		mmu_notifier_unregister(&kvm->arch.pv.mmu_notifier, kvm->mm);
 
 	debug_unregister(kvm->arch.dbf);
-	free_page((unsigned long)kvm->arch.sie_page2);
+	kfree(kvm->arch.sie_page2);
 	kvm_s390_destroy_adapters(kvm);
 	kvm_s390_clear_float_irqs(kvm);
 	kvm_s390_vsie_destroy(kvm);
@@ -3657,13 +3657,13 @@ static void kvm_s390_vcpu_crypto_setup(struct kvm_vcpu *vcpu)
 void kvm_s390_vcpu_unsetup_cmma(struct kvm_vcpu *vcpu)
 {
 	if (vcpu->arch.sie_block->cbrlo)
-		free_page((unsigned long)phys_to_virt(vcpu->arch.sie_block->cbrlo));
+		kfree(phys_to_virt(vcpu->arch.sie_block->cbrlo));
 	vcpu->arch.sie_block->cbrlo = 0;
 }
 
 int kvm_s390_vcpu_setup_cmma(struct kvm_vcpu *vcpu)
 {
-	void *cbrlo_page = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT);
+	void *cbrlo_page = kzalloc(PAGE_SIZE, GFP_KERNEL_ACCOUNT);
 
 	if (!cbrlo_page)
 		return -ENOMEM;

							input: 5145
							output: 31
							thoughts: 1061

**Patch Analysis: s390 KVM Memory Allocation**

Okay, let's dive into this patch and determine its fuzzing potential. The core of this change seems to involve swapping `get_zeroed_page` and `free_page` with `kzalloc` and `kfree` within the s390 KVM code. Specifically, I'm seeing it in `intercept.c`, `interrupt.c`, `priv.c`, and `s390.c`.

Aha, hold on. This is interesting. `get_zeroed_page` is a direct buddy allocator call, grabbing a single page. `kzalloc(PAGE_SIZE, ...)` uses the slab allocator, effectively a `kmalloc-4k` allocation. I'm seeing this with `GFP_KERNEL_ACCOUNT | GFP_DMA` flags in calls like `kvm_s390_gib_init` and `kvm_arch_init_vm`, which then utilize `virt_to_phys` to get the physical address. And similar logic in `kvm_s390_vcpu_setup_cmma` and `kvm_s390_vcpu_unsetup_cmma`.

The slab allocator is indeed page-aligned (4096-byte slab objects). So, the question is *why* this change? Is this purely refactoring, a cleanup, or does it *actually* alter behavior? Is it an optimization aimed at slab allocation, or some subtle semantic change? Let me double-check the instruction for deciding if the patch is worth fuzzing.

Right, so modifications to documentation, Kconfig, comments, purely decorative changes like logging, constant changes without functional impact, unreachable code in virtualized environments, specific hardware-dependent drivers, and tear-down callbacks are all out.

Now, let's consider s390 KVM. Can this be effectively fuzzed, or run within QEMU? Yes, s390 KVM is the KVM hypervisor on the s390x architecture, I know that. But, can it be fuzz tested? QEMU emulates s390x (qemu-system-s390x), but I think KVM inside QEMU on s390x likely needs nested KVM or actual hardware. Syzkaller definitely fuzzes s390x Linux kernels; does it also test s390 KVM if it runs on s390x? Or is it only TCG?

The real question is whether this is adding or modifying logic, or if this is just a mechanical replacement of the allocation routines. What was the motivation for this change? I'm going to dig into the git log and maybe search the tree for context to see what the author was thinking.

{
  "Expression": "kzalloc_obj",
  "PathPrefix": "arch/s390/"
}

{
  "Output": "arch/s390/appldata/appldata_base.c=347=int appldata_register_ops(struct appldata_ops *ops)\n--\narch/s390/appldata/appldata_base.c-351-\narch/s390/appldata/appldata_base.c:352:\tops-\u003ectl_table = kzalloc_objs(struct ctl_table, 1);\narch/s390/appldata/appldata_base.c-353-\tif (!ops-\u003ectl_table)\n--\narch/s390/appldata/appldata_mem.c=129=static int __init appldata_mem_init(void)\n--\narch/s390/appldata/appldata_mem.c-132-\narch/s390/appldata/appldata_mem.c:133:\tops.data = kzalloc_obj(struct appldata_mem_data);\narch/s390/appldata/appldata_mem.c-134-\tif (!ops.data)\n--\narch/s390/appldata/appldata_net_sum.c=131=static int __init appldata_net_init(void)\n--\narch/s390/appldata/appldata_net_sum.c-134-\narch/s390/appldata/appldata_net_sum.c:135:\tops.data = kzalloc_obj(struct appldata_net_sum_data);\narch/s390/appldata/appldata_net_sum.c-136-\tif (!ops.data)\n--\narch/s390/hypfs/hypfs_sprp.c=67=static int __hypfs_sprp_ioctl(void __user *user_area)\n--\narch/s390/hypfs/hypfs_sprp.c-76-\tdata = (void *)get_zeroed_page(GFP_KERNEL);\narch/s390/hypfs/hypfs_sprp.c:77:\tdiag304 = kzalloc_obj(*diag304);\narch/s390/hypfs/hypfs_sprp.c-78-\tif (!data || !diag304)\n--\narch/s390/hypfs/inode.c=291=static int hypfs_init_fs_context(struct fs_context *fc)\n--\narch/s390/hypfs/inode.c-294-\narch/s390/hypfs/inode.c:295:\tsbi = kzalloc_obj(struct hypfs_sb_info);\narch/s390/hypfs/inode.c-296-\tif (!sbi)\n--\narch/s390/include/asm/idals.h=88=static inline int set_normalized_cda(struct ccw1 *ccw, void *vaddr)\n--\narch/s390/include/asm/idals.h-96-\tif (nridaws \u003e 0) {\narch/s390/include/asm/idals.h:97:\t\tidal = kzalloc_objs(*idal, nridaws, GFP_ATOMIC | GFP_DMA);\narch/s390/include/asm/idals.h-98-\t\tif (!idal)\n--\narch/s390/kernel/cert_store.c=315=static int invalidate_keyring_keys(struct key *keyring)\n--\narch/s390/kernel/cert_store.c-324-\tnum_keys = keyring_payload_len / sizeof(key_serial_t);\narch/s390/kernel/cert_store.c:325:\tkey_array = kzalloc_objs(key_serial_t, num_keys);\narch/s390/kernel/cert_store.c-326-\tif (!key_array)\n--\narch/s390/kernel/debug.c=307=static debug_info_t *debug_info_alloc(const char *name, int pages_per_area,\n--\narch/s390/kernel/debug.c-316-\t\tgoto fail_malloc_rc;\narch/s390/kernel/debug.c:317:\trc-\u003eactive_entries = kzalloc_objs(int, nr_areas);\narch/s390/kernel/debug.c-318-\tif (!rc-\u003eactive_entries)\narch/s390/kernel/debug.c-319-\t\tgoto fail_malloc_active_entries;\narch/s390/kernel/debug.c:320:\trc-\u003eactive_pages = kzalloc_objs(int, nr_areas);\narch/s390/kernel/debug.c-321-\tif (!rc-\u003eactive_pages)\n--\narch/s390/kernel/guarded_storage.c=22=static int gs_enable(void)\n--\narch/s390/kernel/guarded_storage.c-26-\tif (!current-\u003ethread.gs_cb) {\narch/s390/kernel/guarded_storage.c:27:\t\tgs_cb = kzalloc_obj(*gs_cb);\narch/s390/kernel/guarded_storage.c-28-\t\tif (!gs_cb)\n--\narch/s390/kernel/guarded_storage.c=52=static int gs_set_bc_cb(struct gs_cb __user *u_gs_cb)\n--\narch/s390/kernel/guarded_storage.c-57-\tif (!gs_cb) {\narch/s390/kernel/guarded_storage.c:58:\t\tgs_cb = kzalloc_obj(*gs_cb);\narch/s390/kernel/guarded_storage.c-59-\t\tif (!gs_cb)\n--\narch/s390/kernel/os_info.c=144=static void os_info_old_init(void)\n--\narch/s390/kernel/os_info.c-156-\t\tgoto fail;\narch/s390/kernel/os_info.c:157:\tos_info_old = kzalloc_obj(*os_info_old);\narch/s390/kernel/os_info.c-158-\tif (!os_info_old)\n--\narch/s390/kernel/perf_cpum_cf.c=251=static int cpum_cf_alloc_cpu(int cpu, unsigned int num)\n--\narch/s390/kernel/perf_cpum_cf.c-264-\tif (!cpuhw) {\narch/s390/kernel/perf_cpum_cf.c:265:\t\tcpuhw = kzalloc_obj(*cpuhw);\narch/s390/kernel/perf_cpum_cf.c-266-\t\tif (cpuhw) {\n--\narch/s390/kernel/perf_cpum_cf.c=1664=static long cfset_ioctl_start(unsigned long arg, struct file *file)\n--\narch/s390/kernel/perf_cpum_cf.c-1689-\narch/s390/kernel/perf_cpum_cf.c:1690:\tpreq = kzalloc_obj(*preq);\narch/s390/kernel/perf_cpum_cf.c-1691-\tif (!preq)\n--\narch/s390/kernel/perf_cpum_sf.c=1592=static void *aux_buffer_setup(struct perf_event *event, void **pages,\n--\narch/s390/kernel/perf_cpum_sf.c-1615-\t/* Allocate aux_buffer struct for the event */\narch/s390/kernel/perf_cpum_sf.c:1616:\taux = kzalloc_obj(struct aux_buffer);\narch/s390/kernel/perf_cpum_sf.c-1617-\tif (!aux)\n--\narch/s390/kernel/perf_pai.c=244=static int pai_alloc_cpu(struct perf_event *event, int cpu)\n--\narch/s390/kernel/perf_pai.c-261-\t\trc = -ENOMEM;\narch/s390/kernel/perf_pai.c:262:\t\tcpump = kzalloc_obj(*cpump);\narch/s390/kernel/perf_pai.c-263-\t\tif (!cpump)\n--\narch/s390/kernel/perf_pai.c=319=static int pai_alloc(struct perf_event *event)\n--\narch/s390/kernel/perf_pai.c-323-\narch/s390/kernel/perf_pai.c:324:\tmaskptr = kzalloc_obj(*maskptr);\narch/s390/kernel/perf_pai.c-325-\tif (!maskptr)\n--\narch/s390/kernel/perf_pai.c=1077=static struct attribute * __init attr_event_init_one(int num,\n--\narch/s390/kernel/perf_pai.c-1082-\narch/s390/kernel/perf_pai.c:1083:\tpa = kzalloc_obj(*pa);\narch/s390/kernel/perf_pai.c-1084-\tif (!pa)\n--\narch/s390/kernel/ptrace.c=741=static int s390_gs_cb_set(struct task_struct *target,\n--\narch/s390/kernel/ptrace.c-751-\tif (!target-\u003ethread.gs_cb) {\narch/s390/kernel/ptrace.c:752:\t\tdata = kzalloc_obj(*data);\narch/s390/kernel/ptrace.c-753-\t\tif (!data)\n--\narch/s390/kernel/ptrace.c=793=static int s390_gs_bc_set(struct task_struct *target,\n--\narch/s390/kernel/ptrace.c-802-\tif (!data) {\narch/s390/kernel/ptrace.c:803:\t\tdata = kzalloc_obj(*data);\narch/s390/kernel/ptrace.c-804-\t\tif (!data)\n--\narch/s390/kernel/ptrace.c=852=static int s390_runtime_instr_set(struct task_struct *target,\n--\narch/s390/kernel/ptrace.c-863-\tif (!target-\u003ethread.ri_cb) {\narch/s390/kernel/ptrace.c:864:\t\tdata = kzalloc_obj(*data);\narch/s390/kernel/ptrace.c-865-\t\tif (!data)\n--\narch/s390/kernel/runtime_instr.c=70=SYSCALL_DEFINE2(s390_runtime_instr, int, command, int, signum)\n--\narch/s390/kernel/runtime_instr.c-85-\tif (!current-\u003ethread.ri_cb) {\narch/s390/kernel/runtime_instr.c:86:\t\tcb = kzalloc_obj(*cb);\narch/s390/kernel/runtime_instr.c-87-\t\tif (!cb)\n--\narch/s390/kernel/smp.c=1121=int __ref smp_rescan_cpus(bool early)\n--\narch/s390/kernel/smp.c-1125-\narch/s390/kernel/smp.c:1126:\tinfo = kzalloc_obj(*info);\narch/s390/kernel/smp.c-1127-\tif (!info)\n--\narch/s390/kernel/vdso.c=129=static struct page ** __init vdso_setup_pages(void *start, void *end)\n--\narch/s390/kernel/vdso.c-134-\narch/s390/kernel/vdso.c:135:\tpagelist = kzalloc_objs(struct page *, pages + 1);\narch/s390/kernel/vdso.c-136-\tif (!pagelist)\n--\narch/s390/kvm/gmap/dat.c=31=int kvm_s390_mmu_cache_topup(struct kvm_s390_mmu_cache *mc)\n--\narch/s390/kvm/gmap/dat.c-47-\tfor ( ; mc-\u003en_rmaps \u003c KVM_S390_MMU_CACHE_N_RMAPS; mc-\u003en_rmaps++) {\narch/s390/kvm/gmap/dat.c:48:\t\to = kzalloc_obj(struct vsie_rmap, GFP_KERNEL_ACCOUNT);\narch/s390/kvm/gmap/dat.c-49-\t\tif (!o)\n--\narch/s390/kvm/gmap/dat.h=591=static inline struct vsie_rmap *kvm_s390_mmu_cache_alloc_rmap(struct kvm_s390_mmu_cache *mc)\n--\narch/s390/kvm/gmap/dat.h-594-\t\treturn mc-\u003ermaps[--mc-\u003en_rmaps];\narch/s390/kvm/gmap/dat.h:595:\treturn kzalloc_obj(struct vsie_rmap, GFP_KVM_S390_MMU_CACHE);\narch/s390/kvm/gmap/dat.h-596-}\n--\narch/s390/kvm/gmap/dat.h=939=static inline struct kvm_s390_mmu_cache *kvm_s390_new_mmu_cache(void)\n--\narch/s390/kvm/gmap/dat.h-942-\narch/s390/kvm/gmap/dat.h:943:\tmc = kzalloc_obj(*mc, GFP_KERNEL_ACCOUNT);\narch/s390/kvm/gmap/dat.h-944-\tif (mc \u0026\u0026 !kvm_s390_mmu_cache_topup(mc))\n--\narch/s390/kvm/gmap/gmap.c=47=struct gmap *gmap_new(struct kvm *kvm, gfn_t limit)\n--\narch/s390/kvm/gmap/gmap.c-54-\narch/s390/kvm/gmap/gmap.c:55:\tgmap = kzalloc_obj(*gmap, GFP_KERNEL_ACCOUNT);\narch/s390/kvm/gmap/gmap.c-56-\tif (!gmap)\n--\narch/s390/kvm/s390/interrupt.c=1749=struct kvm_s390_interrupt_info *kvm_s390_get_io_int(struct kvm *kvm,\n--\narch/s390/kvm/s390/interrupt.c-1773-gisa_out:\narch/s390/kvm/s390/interrupt.c:1774:\ttmp_inti = kzalloc_obj(*inti, GFP_KERNEL_ACCOUNT);\narch/s390/kvm/s390/interrupt.c-1775-\tif (tmp_inti) {\n--\narch/s390/kvm/s390/interrupt.c=2392=static int enqueue_floating_irq(struct kvm_device *dev,\n--\narch/s390/kvm/s390/interrupt.c-2404-\twhile (len \u003e= sizeof(struct kvm_s390_irq)) {\narch/s390/kvm/s390/interrupt.c:2405:\t\tinti = kzalloc_obj(*inti, GFP_KERNEL_ACCOUNT);\narch/s390/kvm/s390/interrupt.c-2406-\t\tif (!inti)\n--\narch/s390/kvm/s390/interrupt.c=2434=static int register_io_adapter(struct kvm_device *dev,\n--\narch/s390/kvm/s390/interrupt.c-2457-\t}\narch/s390/kvm/s390/interrupt.c:2458:\tadapter = kzalloc_obj(*adapter, GFP_KERNEL_ACCOUNT);\narch/s390/kvm/s390/interrupt.c-2459-\tif (!adapter) {\n--\narch/s390/kvm/s390/interrupt.c=2512=static int kvm_s390_adapter_map(struct kvm *kvm, unsigned int id, __u64 addr)\n--\narch/s390/kvm/s390/interrupt.c-2522-\narch/s390/kvm/s390/interrupt.c:2523:\tmap = kzalloc_obj(*map, GFP_KERNEL_ACCOUNT);\narch/s390/kvm/s390/interrupt.c-2524-\tif (!map)\n--\narch/s390/kvm/s390/interrupt.c=2771=static int kvm_s390_inject_airq(struct kvm *kvm,\n--\narch/s390/kvm/s390/interrupt.c-2784-\narch/s390/kvm/s390/interrupt.c:2785:\tinti = kzalloc_obj(*inti, GFP_KERNEL_ACCOUNT);\narch/s390/kvm/s390/interrupt.c-2786-\tif (!inti)\n--\narch/s390/kvm/s390/interrupt.c=3754=int kvm_arch_set_irq_inatomic(struct kvm_kernel_irq_routing_entry *e,\n--\narch/s390/kvm/s390/interrupt.c-3788-\narch/s390/kvm/s390/interrupt.c:3789:\tinti = kzalloc_obj(*inti, GFP_ATOMIC);\narch/s390/kvm/s390/interrupt.c-3790-\tif (!inti) {\n--\narch/s390/kvm/s390/pci.c=52=static int zpci_setup_aipb(u8 nisc)\n--\narch/s390/kvm/s390/pci.c-56-\narch/s390/kvm/s390/pci.c:57:\tzpci_aipb = kzalloc_obj(union zpci_sic_iib);\narch/s390/kvm/s390/pci.c-58-\tif (!zpci_aipb)\n--\narch/s390/kvm/s390/pci.c=120=int kvm_s390_pci_aen_init(u8 nisc)\n--\narch/s390/kvm/s390/pci.c-128-\tmutex_lock(\u0026aift-\u003eaift_lock);\narch/s390/kvm/s390/pci.c:129:\taift-\u003ekzdev = kzalloc_objs(struct kvm_zdev *, ZPCI_NR_DEVICES);\narch/s390/kvm/s390/pci.c-130-\tif (!aift-\u003ekzdev) {\n--\narch/s390/kvm/s390/pci.c=471=static int kvm_s390_pci_dev_open(struct zpci_dev *zdev)\n--\narch/s390/kvm/s390/pci.c-474-\narch/s390/kvm/s390/pci.c:475:\tkzdev = kzalloc_obj(struct kvm_zdev);\narch/s390/kvm/s390/pci.c-476-\tif (!kzdev)\n--\narch/s390/kvm/s390/pci.c=729=int __init kvm_s390_pci_init(void)\n--\narch/s390/kvm/s390/pci.c-736-\narch/s390/kvm/s390/pci.c:737:\taift = kzalloc_obj(struct zpci_aift);\narch/s390/kvm/s390/pci.c-738-\tif (!aift)\n--\narch/s390/kvm/s390/pv.c=476=int kvm_s390_pv_set_aside(struct kvm *kvm, u16 *rc, u16 *rrc)\n--\narch/s390/kvm/s390/pv.c-492-\narch/s390/kvm/s390/pv.c:493:\tpriv = kzalloc_obj(*priv);\narch/s390/kvm/s390/pv.c-494-\tif (!priv)\n--\narch/s390/kvm/s390/s390.c=1473=static int kvm_s390_set_processor(struct kvm *kvm, struct kvm_device_attr *attr)\n--\narch/s390/kvm/s390/s390.c-1483-\t}\narch/s390/kvm/s390/s390.c:1484:\tproc = kzalloc_obj(*proc, GFP_KERNEL_ACCOUNT);\narch/s390/kvm/s390/s390.c-1485-\tif (!proc) {\n--\narch/s390/kvm/s390/s390.c=1679=static int kvm_s390_get_processor(struct kvm *kvm, struct kvm_device_attr *attr)\n--\narch/s390/kvm/s390/s390.c-1683-\narch/s390/kvm/s390/s390.c:1684:\tproc = kzalloc_obj(*proc, GFP_KERNEL_ACCOUNT);\narch/s390/kvm/s390/s390.c-1685-\tif (!proc) {\n--\narch/s390/kvm/s390/s390.c=1707=static int kvm_s390_get_machine(struct kvm *kvm, struct kvm_device_attr *attr)\n--\narch/s390/kvm/s390/s390.c-1711-\narch/s390/kvm/s390/s390.c:1712:\tmach = kzalloc_obj(*mach, GFP_KERNEL_ACCOUNT);\narch/s390/kvm/s390/s390.c-1713-\tif (!mach) {\n--\narch/s390/kvm/s390/s390.c=2900=int kvm_arch_vm_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg)\n--\narch/s390/kvm/s390/s390.c-2917-\t\t\tbreak;\narch/s390/kvm/s390/s390.c:2918:\t\tinti = kzalloc_obj(*inti, GFP_KERNEL_ACCOUNT);\narch/s390/kvm/s390/s390.c-2919-\t\tif (!inti)\n--\narch/s390/kvm/s390/s390.c=3240=int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)\n--\narch/s390/kvm/s390/s390.c-3275-\tBUILD_BUG_ON(sizeof(struct sie_page2) != 4096);\narch/s390/kvm/s390/s390.c:3276:\tkvm-\u003earch.sie_page2 = kzalloc_obj(*kvm-\u003earch.sie_page2,\narch/s390/kvm/s390/s390.c-3277-\t\t\t\t\t  GFP_KERNEL_ACCOUNT | GFP_DMA);\n--\narch/s390/kvm/s390/s390.c=4451=static void __kvm_inject_pfault_token(struct kvm_vcpu *vcpu, bool start_token,\n--\narch/s390/kvm/s390/s390.c-4463-\t} else {\narch/s390/kvm/s390/s390.c:4464:\t\tinti_mem = kzalloc_obj(*inti_mem, GFP_KERNEL_ACCOUNT);\narch/s390/kvm/s390/s390.c-4465-\t\tif (WARN_ON_ONCE(!inti_mem))\n--\narch/s390/mm/extmem.c=297=__segment_load (char *name, int do_nonshared, unsigned long *addr, unsigned long *end)\n--\narch/s390/mm/extmem.c-319-\narch/s390/mm/extmem.c:320:\tseg-\u003eres = kzalloc_obj(struct resource);\narch/s390/mm/extmem.c-321-\tif (seg-\u003eres == NULL) {\n--\narch/s390/net/bpf_jit_comp.c=2386=struct bpf_prog *bpf_int_jit_compile(struct bpf_verifier_env *env, struct bpf_prog *fp)\n--\narch/s390/net/bpf_jit_comp.c-2398-\tif (!jit_data) {\narch/s390/net/bpf_jit_comp.c:2399:\t\tjit_data = kzalloc_obj(*jit_data);\narch/s390/net/bpf_jit_comp.c-2400-\t\tif (!jit_data)\n--\narch/s390/pci/pci.c=522=static struct resource *__alloc_res(struct zpci_dev *zdev, unsigned long start,\n--\narch/s390/pci/pci.c-526-\narch/s390/pci/pci.c:527:\tr = kzalloc_obj(*r);\narch/s390/pci/pci.c-528-\tif (!r)\n--\narch/s390/pci/pci.c=823=struct zpci_dev *zpci_create_device(u32 fid, u32 fh, enum zpci_state state)\n--\narch/s390/pci/pci.c-827-\narch/s390/pci/pci.c:828:\tzdev = kzalloc_obj(*zdev);\narch/s390/pci/pci.c-829-\tif (!zdev)\n--\narch/s390/pci/pci.c=1066=static int zpci_mem_init(void)\n--\narch/s390/pci/pci.c-1077-\narch/s390/pci/pci.c:1078:\tzpci_iomap_start = kzalloc_objs(*zpci_iomap_start, ZPCI_IOMAP_ENTRIES);\narch/s390/pci/pci.c-1079-\tif (!zpci_iomap_start)\n--\narch/s390/pci/pci_bus.c=314=static struct zpci_bus *zpci_bus_alloc(int topo, bool topo_is_tid)\n--\narch/s390/pci/pci_bus.c-317-\narch/s390/pci/pci_bus.c:318:\tzbus = kzalloc_obj(*zbus);\narch/s390/pci/pci_bus.c-319-\tif (!zbus)\n--\narch/s390/pci/pci_irq.c=552=static int __init zpci_directed_irq_init(void)\n--\narch/s390/pci/pci_irq.c-565-\narch/s390/pci/pci_irq.c:566:\tzpci_ibv = kzalloc_objs(*zpci_ibv, num_possible_cpus());\narch/s390/pci/pci_irq.c-567-\tif (!zpci_ibv)\n--\narch/s390/pci/pci_irq.c=590=static int __init zpci_floating_irq_init(void)\narch/s390/pci/pci_irq.c-591-{\narch/s390/pci/pci_irq.c:592:\tzpci_ibv = kzalloc_objs(*zpci_ibv, ZPCI_NR_DEVICES);\narch/s390/pci/pci_irq.c-593-\tif (!zpci_ibv)\n"
}

							input: 14506
							output: 29
							thoughts: 629

**Patch Review: KVM Memory Allocation on s390**

Okay, let's dive back into this patch. I need to make sure I haven't missed anything, so I'm going to carefully step through each change. It looks like we're addressing memory allocation and deallocation within the s390 KVM code. This is critical; even a small leak or misuse can destabilize the entire system, especially in a virtualization context.

The first block, `arch/s390/kvm/s390/intercept.c` specifically the `handle_sthyi` function, is where the initial change comes in; `get_zeroed_page` is being replaced by `kzalloc` for `sctns`. This is a pretty straightforward conversion: `kzalloc` combines the `get_zeroed_page` with a `memset(0)` to initialize the memory. Correspondingly, `free_page` is replaced with `kfree`. That's good; it's cleaner and functionally equivalent. The same pattern holds for `arch/s390/kvm/s390/interrupt.c`, `kvm_s390_gib_destroy` and `kvm_s390_gib_init`, and also `arch/s390/kvm/s390/priv.c` and `handle_stsi`, with the same changes between `get_zeroed_page` and `kzalloc` and the appropriate `free_page` calls being changed to `kfree`.

The fourth chunk, in `arch/s390/kvm/s390/s390.c`, is slightly more involved. Here, within `kvm_arch_init_vm`, `kvm_arch_destroy_vm`, `kvm_s390_vcpu_setup_cmma`, and `kvm_s390_vcpu_unsetup_cmma`, we see the same transition from `get_zeroed_page` to `kzalloc`, but with the addition of `*` for the `kvm->arch.sie_page2` pointer. It looks like it could be calling a helper. And for the other case in this file, we have the same situation as before with the replacement of `free_page` with `kfree` when dealing with the physical memory.

These are all important functions; any memory-related issues in `kvm_arch_init_vm` or `kvm_arch_destroy_vm` are likely to cause some big problems when launching or shutting down VMs. I need to keep an eye on how these function calls are structured. This seems like a pretty standard and sensible change. These functions are often where subtle memory management issues can creep in, so this kind of modernization is usually a good thing. The use of `kzalloc` is generally preferred now because it is cleaner, handles the zeroing internally, and is more consistent. I assume there isn't a significant performance difference here.

Before giving it a stamp of approval, I should check the Kconfig options to verify the change doesn't introduce some unexpected dependency or change the configuration. I'll need to double check the Kconfig for any subtle effects.

I'll search for 'KVM' within the `arch/s390` directory just to make sure I am not missing any dependencies or other relevant Kconfig options to get a full picture.

{
  "Expression": "KVM",
  "PathPrefix": "arch/s390/"
}

{
  "Output": "\nFull output is too long, showing 500 out of 3872 lines.\nUse more precise expression if possible.\n\narch/s390/Kbuild=3=obj-y\t\t\t\t+= mm/\narch/s390/Kbuild:4:obj-$(CONFIG_KVM)\t\t+= kvm/\narch/s390/Kbuild-5-obj-y\t\t\t\t+= crypto/\n--\narch/s390/Kconfig=846=config VFIO_AP\n--\narch/s390/Kconfig-848-\tprompt \"VFIO support for AP devices\"\narch/s390/Kconfig:849:\tdepends on KVM\narch/s390/Kconfig-850-\tdepends on VFIO\n--\narch/s390/Kconfig=990=config S390_GUEST\n--\narch/s390/Kconfig-1000-\t  Select this option if you want to run the kernel as a guest under\narch/s390/Kconfig:1001:\t  the KVM hypervisor.\narch/s390/Kconfig-1002-\n--\narch/s390/boot/ipl_parm.c=249=void parse_boot_command_line(void)\n--\narch/s390/boot/ipl_parm.c-302-\narch/s390/boot/ipl_parm.c:303:#if IS_ENABLED(CONFIG_KVM)\narch/s390/boot/ipl_parm.c-304-\t\tif (!strcmp(param, \"prot_virt\")) {\n--\narch/s390/boot/startup.c=52=static void detect_machine_type(void)\n--\narch/s390/boot/startup.c-65-\tif (!memcmp(vmms-\u003evm[0].cpi, \"\\xd2\\xe5\\xd4\", 3))\narch/s390/boot/startup.c:66:\t\tset_machine_feature(MFEATURE_KVM);\narch/s390/boot/startup.c-67-\telse if (!memcmp(vmms-\u003evm[0].cpi, \"\\xa9\\x61\\xe5\\xd4\", 4))\n--\narch/s390/boot/uv.c=15=void uv_query_info(void)\n--\narch/s390/boot/uv.c-28-\narch/s390/boot/uv.c:29:\tif (IS_ENABLED(CONFIG_KVM)) {\narch/s390/boot/uv.c-30-\t\tmemcpy(uv_info.inst_calls_list, uvcb.inst_calls_list, sizeof(uv_info.inst_calls_list));\n--\narch/s390/configs/debug_defconfig=67=CONFIG_S390_HYPFS_FS=y\narch/s390/configs/debug_defconfig:68:CONFIG_KVM=m\narch/s390/configs/debug_defconfig:69:CONFIG_KVM_S390_UCONTROL=y\narch/s390/configs/debug_defconfig-70-CONFIG_S390_UNWIND_SELFTEST=m\n--\narch/s390/configs/defconfig=65=CONFIG_S390_HYPFS_FS=y\narch/s390/configs/defconfig:66:CONFIG_KVM=m\narch/s390/configs/defconfig-67-CONFIG_S390_UNWIND_SELFTEST=m\n--\narch/s390/include/asm/entry-common.h=54=static __always_inline bool arch_in_rcu_eqs(void)\narch/s390/include/asm/entry-common.h-55-{\narch/s390/include/asm/entry-common.h:56:\tif (IS_ENABLED(CONFIG_KVM))\narch/s390/include/asm/entry-common.h-57-\t\treturn current-\u003eflags \u0026 PF_VCPU;\n--\narch/s390/include/asm/gmap_helpers.h-2-/*\narch/s390/include/asm/gmap_helpers.h:3: *  Helper functions for KVM guest address space mapping code\narch/s390/include/asm/gmap_helpers.h-4- *\n--\narch/s390/include/asm/kvm_host.h-2-\narch/s390/include/asm/kvm_host.h:3:#ifndef ASM_KVM_HOST_H\narch/s390/include/asm/kvm_host.h:4:#define ASM_KVM_HOST_H\narch/s390/include/asm/kvm_host.h-5-\n--\narch/s390/include/asm/kvm_host.h-64-\narch/s390/include/asm/kvm_host.h:65:#endif /* ASM_KVM_HOST_H */\n--\narch/s390/include/asm/kvm_host_s390.h-10-\narch/s390/include/asm/kvm_host_s390.h:11:#ifndef ASM_KVM_HOST_S390_H\narch/s390/include/asm/kvm_host_s390.h:12:#define ASM_KVM_HOST_S390_H\narch/s390/include/asm/kvm_host_s390.h-13-\n--\narch/s390/include/asm/kvm_host_s390.h-29-\narch/s390/include/asm/kvm_host_s390.h:30:#define KVM_HAVE_MMU_RWLOCK\narch/s390/include/asm/kvm_host_s390.h:31:#define KVM_MAX_VCPUS 255\narch/s390/include/asm/kvm_host_s390.h-32-\narch/s390/include/asm/kvm_host_s390.h:33:#define KVM_INTERNAL_MEM_SLOTS 1\narch/s390/include/asm/kvm_host_s390.h-34-\narch/s390/include/asm/kvm_host_s390.h:35:#define KVM_S390_MANAGES_S390_GUEST 1\narch/s390/include/asm/kvm_host_s390.h-36-\n--\narch/s390/include/asm/kvm_host_s390.h-41- */\narch/s390/include/asm/kvm_host_s390.h:42:#define KVM_NR_IRQCHIPS 1\narch/s390/include/asm/kvm_host_s390.h:43:#define KVM_IRQCHIP_NUM_PINS 1\narch/s390/include/asm/kvm_host_s390.h:44:#define KVM_HALT_POLL_NS_DEFAULT 50000\narch/s390/include/asm/kvm_host_s390.h-45-\narch/s390/include/asm/kvm_host_s390.h-46-/* s390-specific vcpu-\u003erequests bit members */\narch/s390/include/asm/kvm_host_s390.h:47:#define KVM_REQ_ENABLE_IBS\tKVM_ARCH_REQ(0)\narch/s390/include/asm/kvm_host_s390.h:48:#define KVM_REQ_DISABLE_IBS\tKVM_ARCH_REQ(1)\narch/s390/include/asm/kvm_host_s390.h:49:#define KVM_REQ_ICPT_OPEREXC\tKVM_ARCH_REQ(2)\narch/s390/include/asm/kvm_host_s390.h:50:#define KVM_REQ_START_MIGRATION KVM_ARCH_REQ(3)\narch/s390/include/asm/kvm_host_s390.h:51:#define KVM_REQ_STOP_MIGRATION  KVM_ARCH_REQ(4)\narch/s390/include/asm/kvm_host_s390.h:52:#define KVM_REQ_VSIE_RESTART\tKVM_ARCH_REQ(5)\narch/s390/include/asm/kvm_host_s390.h:53:#define KVM_REQ_REFRESH_GUEST_PREFIX\t\\\narch/s390/include/asm/kvm_host_s390.h:54:\tKVM_ARCH_REQ_FLAGS(6, KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP)\narch/s390/include/asm/kvm_host_s390.h-55-\n--\narch/s390/include/asm/kvm_host_s390.h=156=enum irq_types {\n--\narch/s390/include/asm/kvm_host_s390.h-190- */\narch/s390/include/asm/kvm_host_s390.h:191:#define KVM_S390_MAX_VIRTIO_IRQS 87381\narch/s390/include/asm/kvm_host_s390.h-192-\n--\narch/s390/include/asm/kvm_host_s390.h=268=struct kvm_s390_local_interrupt {\narch/s390/include/asm/kvm_host_s390.h-269-\tspinlock_t lock;\narch/s390/include/asm/kvm_host_s390.h:270:\tDECLARE_BITMAP(sigp_emerg_pending, KVM_MAX_VCPUS);\narch/s390/include/asm/kvm_host_s390.h-271-\tstruct kvm_s390_irq_payload irq;\n--\narch/s390/include/asm/kvm_host_s390.h-294-\narch/s390/include/asm/kvm_host_s390.h:295:#define KVM_S390_AIS_MODE_ALL    0\narch/s390/include/asm/kvm_host_s390.h:296:#define KVM_S390_AIS_MODE_SINGLE 1\narch/s390/include/asm/kvm_host_s390.h-297-\n--\narch/s390/include/asm/kvm_host_s390.h=319=struct kvm_hw_bp_info_arch {\n--\narch/s390/include/asm/kvm_host_s390.h-325- * Only the upper 16 bits of kvm_guest_debug-\u003econtrol are arch specific.\narch/s390/include/asm/kvm_host_s390.h:326: * Further KVM_GUESTDBG flags which an be used from userspace can be found in\narch/s390/include/asm/kvm_host_s390.h-327- * arch/s390/include/uapi/asm/kvm.h\narch/s390/include/asm/kvm_host_s390.h-328- */\narch/s390/include/asm/kvm_host_s390.h:329:#define KVM_GUESTDBG_EXIT_PENDING 0x10000000\narch/s390/include/asm/kvm_host_s390.h-330-\narch/s390/include/asm/kvm_host_s390.h-331-#define guestdbg_enabled(vcpu) \\\narch/s390/include/asm/kvm_host_s390.h:332:\t\t(vcpu-\u003eguest_debug \u0026 KVM_GUESTDBG_ENABLE)\narch/s390/include/asm/kvm_host_s390.h-333-#define guestdbg_sstep_enabled(vcpu) \\\narch/s390/include/asm/kvm_host_s390.h:334:\t\t(vcpu-\u003eguest_debug \u0026 KVM_GUESTDBG_SINGLESTEP)\narch/s390/include/asm/kvm_host_s390.h-335-#define guestdbg_hw_bp_enabled(vcpu) \\\narch/s390/include/asm/kvm_host_s390.h:336:\t\t(vcpu-\u003eguest_debug \u0026 KVM_GUESTDBG_USE_HW_BP)\narch/s390/include/asm/kvm_host_s390.h-337-#define guestdbg_exit_pending(vcpu) (guestdbg_enabled(vcpu) \u0026\u0026 \\\narch/s390/include/asm/kvm_host_s390.h:338:\t\t(vcpu-\u003eguest_debug \u0026 KVM_GUESTDBG_EXIT_PENDING))\narch/s390/include/asm/kvm_host_s390.h-339-\narch/s390/include/asm/kvm_host_s390.h:340:#define KVM_GUESTDBG_VALID_MASK \\\narch/s390/include/asm/kvm_host_s390.h:341:\t\t(KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_SINGLESTEP |\\\narch/s390/include/asm/kvm_host_s390.h:342:\t\tKVM_GUESTDBG_USE_HW_BP | KVM_GUESTDBG_EXIT_PENDING)\narch/s390/include/asm/kvm_host_s390.h-343-\n--\narch/s390/include/asm/kvm_host_s390.h=576=struct kvm_s390_vsie {\n--\narch/s390/include/asm/kvm_host_s390.h-580-\tint next;\narch/s390/include/asm/kvm_host_s390.h:581:\tstruct vsie_page *pages[KVM_MAX_VCPUS];\narch/s390/include/asm/kvm_host_s390.h-582-};\n--\narch/s390/include/asm/kvm_host_s390.h=590=struct kvm_s390_gisa_interrupt {\n--\narch/s390/include/asm/kvm_host_s390.h-594-\tu64 expires;\narch/s390/include/asm/kvm_host_s390.h:595:\tDECLARE_BITMAP(kicked_mask, KVM_MAX_VCPUS);\narch/s390/include/asm/kvm_host_s390.h-596-};\n--\narch/s390/include/asm/kvm_host_s390.h=613=struct kvm_arch {\n--\narch/s390/include/asm/kvm_host_s390.h-645-\t/* subset of available cpu features enabled by user space */\narch/s390/include/asm/kvm_host_s390.h:646:\tDECLARE_BITMAP(cpu_feat, KVM_S390_VM_CPU_FEAT_NR_BITS);\narch/s390/include/asm/kvm_host_s390.h-647-\t/* indexed by vcpu_idx */\narch/s390/include/asm/kvm_host_s390.h:648:\tDECLARE_BITMAP(idle_mask, KVM_MAX_VCPUS);\narch/s390/include/asm/kvm_host_s390.h-649-\tstruct kvm_s390_gisa_interrupt gisa_int;\n--\narch/s390/include/asm/kvm_host_s390.h-655-\narch/s390/include/asm/kvm_host_s390.h:656:#define KVM_HVA_ERR_BAD\t\t(-1UL)\narch/s390/include/asm/kvm_host_s390.h:657:#define KVM_HVA_ERR_RO_BAD\t(-2UL)\narch/s390/include/asm/kvm_host_s390.h-658-\n--\narch/s390/include/asm/kvm_host_s390.h=717=static inline void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) {}\narch/s390/include/asm/kvm_host_s390.h-718-\narch/s390/include/asm/kvm_host_s390.h:719:#define __KVM_HAVE_ARCH_VM_FREE\narch/s390/include/asm/kvm_host_s390.h-720-void kvm_arch_free_vm(struct kvm *kvm);\n--\narch/s390/include/asm/kvm_host_s390.h=727=extern struct zpci_kvm_hook zpci_kvm_hook;\narch/s390/include/asm/kvm_host_s390.h-728-\narch/s390/include/asm/kvm_host_s390.h:729:#endif /* ASM_KVM_HOST_S390_H */\n--\narch/s390/include/asm/kvm_host_s390_types.h-2-\narch/s390/include/asm/kvm_host_s390_types.h:3:#ifndef _ASM_KVM_HOST_S390_TYPES_H\narch/s390/include/asm/kvm_host_s390_types.h:4:#define _ASM_KVM_HOST_S390_TYPES_H\narch/s390/include/asm/kvm_host_s390_types.h-5-\n--\narch/s390/include/asm/kvm_host_s390_types.h-8-\narch/s390/include/asm/kvm_host_s390_types.h:9:#define KVM_S390_BSCA_CPU_SLOTS 64\narch/s390/include/asm/kvm_host_s390_types.h:10:#define KVM_S390_ESCA_CPU_SLOTS 248\narch/s390/include/asm/kvm_host_s390_types.h-11-\n--\narch/s390/include/asm/kvm_host_s390_types.h=72=struct bsca_block {\n--\narch/s390/include/asm/kvm_host_s390_types.h-77-\t__u8\treserved2[4];\narch/s390/include/asm/kvm_host_s390_types.h:78:\tstruct bsca_entry cpu[KVM_S390_BSCA_CPU_SLOTS];\narch/s390/include/asm/kvm_host_s390_types.h-79-};\n--\narch/s390/include/asm/kvm_host_s390_types.h=81=struct esca_block {\n--\narch/s390/include/asm/kvm_host_s390_types.h-87-\t__u64\treserved3[20];\narch/s390/include/asm/kvm_host_s390_types.h:88:\tstruct esca_entry cpu[KVM_S390_ESCA_CPU_SLOTS];\narch/s390/include/asm/kvm_host_s390_types.h-89-};\n--\narch/s390/include/asm/kvm_host_s390_types.h=139=struct kvm_s390_sie_block {\n--\narch/s390/include/asm/kvm_host_s390_types.h-258-\t__u8\treservedb0[8];\t\t/* 0x00b0 */\narch/s390/include/asm/kvm_host_s390_types.h:259:#define HPID_KVM\t0x4\narch/s390/include/asm/kvm_host_s390_types.h-260-#define HPID_VSIE\t0x5\n--\narch/s390/include/asm/kvm_host_s390_types.h=339=struct sie_page {\n--\narch/s390/include/asm/kvm_host_s390_types.h-348-\narch/s390/include/asm/kvm_host_s390_types.h:349:#endif /* _ASM_KVM_HOST_S390_TYPES_H */\n--\narch/s390/include/asm/kvm_host_types.h-2-\narch/s390/include/asm/kvm_host_types.h:3:#ifndef ASM_KVM_HOST_TYPES_H\narch/s390/include/asm/kvm_host_types.h:4:#define ASM_KVM_HOST_TYPES_H\narch/s390/include/asm/kvm_host_types.h-5-\n--\narch/s390/include/asm/kvm_host_types.h-7-\narch/s390/include/asm/kvm_host_types.h:8:#endif /* ASM_KVM_HOST_TYPES_H */\n--\narch/s390/include/asm/kvm_para.h-9-/*\narch/s390/include/asm/kvm_para.h:10: * Hypercalls for KVM on s390. The calling convention is similar to the\narch/s390/include/asm/kvm_para.h-11- * s390 ABI, so we use R2-R6 for parameters 1-5. In addition we use R1\n--\narch/s390/include/asm/kvm_para.h-15- * the instruction encoded number, but specify the number in R1 and\narch/s390/include/asm/kvm_para.h:16: * use 0x500 as KVM hypercall\narch/s390/include/asm/kvm_para.h-17- *\n--\narch/s390/include/asm/kvm_para.h-20- */\narch/s390/include/asm/kvm_para.h:21:#ifndef __S390_KVM_PARA_H\narch/s390/include/asm/kvm_para.h:22:#define __S390_KVM_PARA_H\narch/s390/include/asm/kvm_para.h-23-\n--\narch/s390/include/asm/kvm_para.h-69-\narch/s390/include/asm/kvm_para.h:70:#define GENERATE_KVM_HYPERCALL_FUNC(args)\t\t\t\t\\\narch/s390/include/asm/kvm_para.h-71-static inline\t\t\t\t\t\t\t\t\\\n--\narch/s390/include/asm/kvm_para.h=87=long kvm_hypercall##args(unsigned long nr HYPERCALL_PARM_##args)\t\\\n--\narch/s390/include/asm/kvm_para.h-92-\narch/s390/include/asm/kvm_para.h:93:GENERATE_KVM_HYPERCALL_FUNC(0)\narch/s390/include/asm/kvm_para.h:94:GENERATE_KVM_HYPERCALL_FUNC(1)\narch/s390/include/asm/kvm_para.h:95:GENERATE_KVM_HYPERCALL_FUNC(2)\narch/s390/include/asm/kvm_para.h:96:GENERATE_KVM_HYPERCALL_FUNC(3)\narch/s390/include/asm/kvm_para.h:97:GENERATE_KVM_HYPERCALL_FUNC(4)\narch/s390/include/asm/kvm_para.h:98:GENERATE_KVM_HYPERCALL_FUNC(5)\narch/s390/include/asm/kvm_para.h:99:GENERATE_KVM_HYPERCALL_FUNC(6)\narch/s390/include/asm/kvm_para.h-100-\n--\narch/s390/include/asm/kvm_para.h=118=static inline bool kvm_check_and_clear_guest_paused(void)\n--\narch/s390/include/asm/kvm_para.h-122-\narch/s390/include/asm/kvm_para.h:123:#endif /* __S390_KVM_PARA_H */\n--\narch/s390/include/asm/machine.h-18-#define MFEATURE_VM\t\t7\narch/s390/include/asm/machine.h:19:#define MFEATURE_KVM\t\t8\narch/s390/include/asm/machine.h-20-#define MFEATURE_LPAR\t\t9\n--\narch/s390/include/asm/machine.h=95=DEFINE_MACHINE_HAS_FEATURE(vm, MFEATURE_VM)\narch/s390/include/asm/machine.h:96:DEFINE_MACHINE_HAS_FEATURE(kvm, MFEATURE_KVM)\narch/s390/include/asm/machine.h-97-DEFINE_MACHINE_HAS_FEATURE(lpar, MFEATURE_LPAR)\n--\narch/s390/include/asm/mmu_context.h=20=static inline int init_new_context(struct task_struct *tsk,\n--\narch/s390/include/asm/mmu_context.h-31-\tmm-\u003econtext.flush_mm = 0;\narch/s390/include/asm/mmu_context.h:32:#if IS_ENABLED(CONFIG_KVM)\narch/s390/include/asm/mmu_context.h-33-\tmm-\u003econtext.allow_cow_sharing = 1;\n--\narch/s390/include/asm/pgtable.h=549=static inline int mm_is_protected(struct mm_struct *mm)\narch/s390/include/asm/pgtable.h-550-{\narch/s390/include/asm/pgtable.h:551:#if IS_ENABLED(CONFIG_KVM)\narch/s390/include/asm/pgtable.h-552-\tif (unlikely(atomic_read(\u0026mm-\u003econtext.protected_count)))\n--\narch/s390/include/asm/pgtable.h=594=static inline int mm_forbids_zeropage(struct mm_struct *mm)\narch/s390/include/asm/pgtable.h-595-{\narch/s390/include/asm/pgtable.h:596:#if IS_ENABLED(CONFIG_KVM)\narch/s390/include/asm/pgtable.h-597-\tif (!mm-\u003econtext.allow_cow_sharing)\n--\narch/s390/include/asm/thread_info.h=52=void arch_setup_new_exec(void);\n--\narch/s390/include/asm/thread_info.h-70-#define TIF_GUARDED_STORAGE\t17\t/* load guarded storage control block */\narch/s390/include/asm/thread_info.h:71:#define TIF_ISOLATE_BP_GUEST\t18\t/* Run KVM guests with isolated BP */\narch/s390/include/asm/thread_info.h-72-#define TIF_PER_TRAP\t\t19\t/* Need to handle PER trap on exit to usermode */\n--\narch/s390/include/uapi/asm/kvm.h-1-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */\narch/s390/include/uapi/asm/kvm.h:2:#ifndef __LINUX_KVM_S390_H\narch/s390/include/uapi/asm/kvm.h:3:#define __LINUX_KVM_S390_H\narch/s390/include/uapi/asm/kvm.h-4-/*\narch/s390/include/uapi/asm/kvm.h:5: * KVM s390 specific structures and definitions\narch/s390/include/uapi/asm/kvm.h-6- *\n--\narch/s390/include/uapi/asm/kvm.h-13-\narch/s390/include/uapi/asm/kvm.h:14:#define __KVM_S390\narch/s390/include/uapi/asm/kvm.h-15-\narch/s390/include/uapi/asm/kvm.h=16=struct kvm_s390_skeys {\n--\narch/s390/include/uapi/asm/kvm.h-23-\narch/s390/include/uapi/asm/kvm.h:24:#define KVM_S390_CMMA_PEEK (1 \u003c\u003c 0)\narch/s390/include/uapi/asm/kvm.h-25-\n--\narch/s390/include/uapi/asm/kvm.h-32- * @count: Size of the result buffer.\narch/s390/include/uapi/asm/kvm.h:33: * @flags: Control operation mode via KVM_S390_CMMA_* flags\narch/s390/include/uapi/asm/kvm.h:34: * @remaining: Used with KVM_S390_GET_CMMA_BITS. Indicates how many dirty\narch/s390/include/uapi/asm/kvm.h-35- *             pages are still remaining.\narch/s390/include/uapi/asm/kvm.h:36: * @mask: Used with KVM_S390_SET_CMMA_BITS. Bitmap of bits to actually set\narch/s390/include/uapi/asm/kvm.h-37- *        in the PGSTE.\n--\narch/s390/include/uapi/asm/kvm.h-39- *\narch/s390/include/uapi/asm/kvm.h:40: * Used in KVM_S390_{G,S}ET_CMMA_BITS ioctls.\narch/s390/include/uapi/asm/kvm.h-41- */\narch/s390/include/uapi/asm/kvm.h=42=struct kvm_s390_cmma_log {\n--\narch/s390/include/uapi/asm/kvm.h-52-\narch/s390/include/uapi/asm/kvm.h:53:#define KVM_S390_RESET_POR       1\narch/s390/include/uapi/asm/kvm.h:54:#define KVM_S390_RESET_CLEAR     2\narch/s390/include/uapi/asm/kvm.h:55:#define KVM_S390_RESET_SUBSYSTEM 4\narch/s390/include/uapi/asm/kvm.h:56:#define KVM_S390_RESET_CPU_INIT  8\narch/s390/include/uapi/asm/kvm.h:57:#define KVM_S390_RESET_IPL       16\narch/s390/include/uapi/asm/kvm.h-58-\narch/s390/include/uapi/asm/kvm.h:59:/* for KVM_S390_MEM_OP */\narch/s390/include/uapi/asm/kvm.h-60-struct kvm_s390_mem_op {\n--\narch/s390/include/uapi/asm/kvm.h-78-/* types for kvm_s390_mem_op-\u003eop */\narch/s390/include/uapi/asm/kvm.h:79:#define KVM_S390_MEMOP_LOGICAL_READ\t0\narch/s390/include/uapi/asm/kvm.h:80:#define KVM_S390_MEMOP_LOGICAL_WRITE\t1\narch/s390/include/uapi/asm/kvm.h:81:#define KVM_S390_MEMOP_SIDA_READ\t2\narch/s390/include/uapi/asm/kvm.h:82:#define KVM_S390_MEMOP_SIDA_WRITE\t3\narch/s390/include/uapi/asm/kvm.h:83:#define KVM_S390_MEMOP_ABSOLUTE_READ\t4\narch/s390/include/uapi/asm/kvm.h:84:#define KVM_S390_MEMOP_ABSOLUTE_WRITE\t5\narch/s390/include/uapi/asm/kvm.h:85:#define KVM_S390_MEMOP_ABSOLUTE_CMPXCHG\t6\narch/s390/include/uapi/asm/kvm.h-86-\narch/s390/include/uapi/asm/kvm.h-87-/* flags for kvm_s390_mem_op-\u003eflags */\narch/s390/include/uapi/asm/kvm.h:88:#define KVM_S390_MEMOP_F_CHECK_ONLY\t\t(1ULL \u003c\u003c 0)\narch/s390/include/uapi/asm/kvm.h:89:#define KVM_S390_MEMOP_F_INJECT_EXCEPTION\t(1ULL \u003c\u003c 1)\narch/s390/include/uapi/asm/kvm.h:90:#define KVM_S390_MEMOP_F_SKEY_PROTECTION\t(1ULL \u003c\u003c 2)\narch/s390/include/uapi/asm/kvm.h-91-\narch/s390/include/uapi/asm/kvm.h:92:/* flags specifying extension support via KVM_CAP_S390_MEM_OP_EXTENSION */\narch/s390/include/uapi/asm/kvm.h:93:#define KVM_S390_MEMOP_EXTENSION_CAP_BASE\t(1 \u003c\u003c 0)\narch/s390/include/uapi/asm/kvm.h:94:#define KVM_S390_MEMOP_EXTENSION_CAP_CMPXCHG\t(1 \u003c\u003c 1)\narch/s390/include/uapi/asm/kvm.h-95-\narch/s390/include/uapi/asm/kvm.h=96=struct kvm_s390_psw {\n--\narch/s390/include/uapi/asm/kvm.h-101-/* valid values for type in kvm_s390_interrupt */\narch/s390/include/uapi/asm/kvm.h:102:#define KVM_S390_SIGP_STOP\t\t0xfffe0000u\narch/s390/include/uapi/asm/kvm.h:103:#define KVM_S390_PROGRAM_INT\t\t0xfffe0001u\narch/s390/include/uapi/asm/kvm.h:104:#define KVM_S390_SIGP_SET_PREFIX\t0xfffe0002u\narch/s390/include/uapi/asm/kvm.h:105:#define KVM_S390_RESTART\t\t0xfffe0003u\narch/s390/include/uapi/asm/kvm.h:106:#define KVM_S390_INT_PFAULT_INIT\t0xfffe0004u\narch/s390/include/uapi/asm/kvm.h:107:#define KVM_S390_INT_PFAULT_DONE\t0xfffe0005u\narch/s390/include/uapi/asm/kvm.h:108:#define KVM_S390_MCHK\t\t\t0xfffe1000u\narch/s390/include/uapi/asm/kvm.h:109:#define KVM_S390_INT_CLOCK_COMP\t\t0xffff1004u\narch/s390/include/uapi/asm/kvm.h:110:#define KVM_S390_INT_CPU_TIMER\t\t0xffff1005u\narch/s390/include/uapi/asm/kvm.h:111:#define KVM_S390_INT_VIRTIO\t\t0xffff2603u\narch/s390/include/uapi/asm/kvm.h:112:#define KVM_S390_INT_SERVICE\t\t0xffff2401u\narch/s390/include/uapi/asm/kvm.h:113:#define KVM_S390_INT_EMERGENCY\t\t0xffff1201u\narch/s390/include/uapi/asm/kvm.h:114:#define KVM_S390_INT_EXTERNAL_CALL\t0xffff1202u\narch/s390/include/uapi/asm/kvm.h-115-/* Anything below 0xfffe0000u is taken by INT_IO */\narch/s390/include/uapi/asm/kvm.h:116:#define KVM_S390_INT_IO(ai,cssid,ssid,schid)   \\\narch/s390/include/uapi/asm/kvm.h-117-\t(((schid)) |\t\t\t       \\\n--\narch/s390/include/uapi/asm/kvm.h-120-\t ((ai) \u003c\u003c 26))\narch/s390/include/uapi/asm/kvm.h:121:#define KVM_S390_INT_IO_MIN\t\t0x00000000u\narch/s390/include/uapi/asm/kvm.h:122:#define KVM_S390_INT_IO_MAX\t\t0xfffdffffu\narch/s390/include/uapi/asm/kvm.h:123:#define KVM_S390_INT_IO_AI_MASK\t\t0x04000000u\narch/s390/include/uapi/asm/kvm.h-124-\n--\narch/s390/include/uapi/asm/kvm.h=145=struct kvm_s390_pgm_info {\n--\narch/s390/include/uapi/asm/kvm.h-156-\t__u8 op_access_id;\narch/s390/include/uapi/asm/kvm.h:157:#define KVM_S390_PGM_FLAGS_ILC_VALID\t0x01\narch/s390/include/uapi/asm/kvm.h:158:#define KVM_S390_PGM_FLAGS_ILC_0\t0x02\narch/s390/include/uapi/asm/kvm.h:159:#define KVM_S390_PGM_FLAGS_ILC_1\t0x04\narch/s390/include/uapi/asm/kvm.h:160:#define KVM_S390_PGM_FLAGS_ILC_MASK\t0x06\narch/s390/include/uapi/asm/kvm.h:161:#define KVM_S390_PGM_FLAGS_NO_REWIND\t0x08\narch/s390/include/uapi/asm/kvm.h-162-\t__u8 flags;\n--\narch/s390/include/uapi/asm/kvm.h=174=struct kvm_s390_emerg_info {\n--\narch/s390/include/uapi/asm/kvm.h-177-\narch/s390/include/uapi/asm/kvm.h:178:#define KVM_S390_STOP_FLAG_STORE_STATUS\t0x01\narch/s390/include/uapi/asm/kvm.h-179-struct kvm_s390_stop_info {\n--\narch/s390/include/uapi/asm/kvm.h=231=enum pv_cmd_dmp_id {\narch/s390/include/uapi/asm/kvm.h:232:\tKVM_PV_DUMP_INIT,\narch/s390/include/uapi/asm/kvm.h:233:\tKVM_PV_DUMP_CONFIG_STOR_STATE,\narch/s390/include/uapi/asm/kvm.h:234:\tKVM_PV_DUMP_COMPLETE,\narch/s390/include/uapi/asm/kvm.h:235:\tKVM_PV_DUMP_CPU,\narch/s390/include/uapi/asm/kvm.h-236-};\n--\narch/s390/include/uapi/asm/kvm.h=246=enum pv_cmd_info_id {\narch/s390/include/uapi/asm/kvm.h:247:\tKVM_PV_INFO_VM,\narch/s390/include/uapi/asm/kvm.h:248:\tKVM_PV_INFO_DUMP,\narch/s390/include/uapi/asm/kvm.h-249-};\n--\narch/s390/include/uapi/asm/kvm.h=280=enum pv_cmd_id {\narch/s390/include/uapi/asm/kvm.h:281:\tKVM_PV_ENABLE,\narch/s390/include/uapi/asm/kvm.h:282:\tKVM_PV_DISABLE,\narch/s390/include/uapi/asm/kvm.h:283:\tKVM_PV_SET_SEC_PARMS,\narch/s390/include/uapi/asm/kvm.h:284:\tKVM_PV_UNPACK,\narch/s390/include/uapi/asm/kvm.h:285:\tKVM_PV_VERIFY,\narch/s390/include/uapi/asm/kvm.h:286:\tKVM_PV_PREP_RESET,\narch/s390/include/uapi/asm/kvm.h:287:\tKVM_PV_UNSHARE_ALL,\narch/s390/include/uapi/asm/kvm.h:288:\tKVM_PV_INFO,\narch/s390/include/uapi/asm/kvm.h:289:\tKVM_PV_DUMP,\narch/s390/include/uapi/asm/kvm.h:290:\tKVM_PV_ASYNC_CLEANUP_PREPARE,\narch/s390/include/uapi/asm/kvm.h:291:\tKVM_PV_ASYNC_CLEANUP_PERFORM,\narch/s390/include/uapi/asm/kvm.h-292-};\n--\narch/s390/include/uapi/asm/kvm.h=303=struct kvm_s390_zpci_op {\n--\narch/s390/include/uapi/asm/kvm.h-308-\tunion {\narch/s390/include/uapi/asm/kvm.h:309:\t\t/* for KVM_S390_ZPCIOP_REG_AEN */\narch/s390/include/uapi/asm/kvm.h-310-\t\tstruct {\n--\narch/s390/include/uapi/asm/kvm.h-323-/* types for kvm_s390_zpci_op-\u003eop */\narch/s390/include/uapi/asm/kvm.h:324:#define KVM_S390_ZPCIOP_REG_AEN                0\narch/s390/include/uapi/asm/kvm.h:325:#define KVM_S390_ZPCIOP_DEREG_AEN      1\narch/s390/include/uapi/asm/kvm.h-326-\narch/s390/include/uapi/asm/kvm.h-327-/* flags for kvm_s390_zpci_op-\u003eu.reg_aen.flags */\narch/s390/include/uapi/asm/kvm.h:328:#define KVM_S390_ZPCIOP_REGAEN_HOST    (1 \u003c\u003c 0)\narch/s390/include/uapi/asm/kvm.h-329-\narch/s390/include/uapi/asm/kvm.h-330-/* Device control API: s390-specific devices */\narch/s390/include/uapi/asm/kvm.h:331:#define KVM_DEV_FLIC_GET_ALL_IRQS\t1\narch/s390/include/uapi/asm/kvm.h:332:#define KVM_DEV_FLIC_ENQUEUE\t\t2\narch/s390/include/uapi/asm/kvm.h:333:#define KVM_DEV_FLIC_CLEAR_IRQS\t\t3\narch/s390/include/uapi/asm/kvm.h:334:#define KVM_DEV_FLIC_APF_ENABLE\t\t4\narch/s390/include/uapi/asm/kvm.h:335:#define KVM_DEV_FLIC_APF_DISABLE_WAIT\t5\narch/s390/include/uapi/asm/kvm.h:336:#define KVM_DEV_FLIC_ADAPTER_REGISTER\t6\narch/s390/include/uapi/asm/kvm.h:337:#define KVM_DEV_FLIC_ADAPTER_MODIFY\t7\narch/s390/include/uapi/asm/kvm.h:338:#define KVM_DEV_FLIC_CLEAR_IO_IRQ\t8\narch/s390/include/uapi/asm/kvm.h:339:#define KVM_DEV_FLIC_AISM\t\t9\narch/s390/include/uapi/asm/kvm.h:340:#define KVM_DEV_FLIC_AIRQ_INJECT\t10\narch/s390/include/uapi/asm/kvm.h:341:#define KVM_DEV_FLIC_AISM_ALL\t\t11\narch/s390/include/uapi/asm/kvm.h-342-/*\narch/s390/include/uapi/asm/kvm.h-343- * We can have up to 4*64k pending subchannels + 8 adapter interrupts,\narch/s390/include/uapi/asm/kvm.h:344: * as well as up  to ASYNC_PF_PER_VCPU*KVM_MAX_VCPUS pfault done interrupts.\narch/s390/include/uapi/asm/kvm.h-345- * There are also sclp and machine checks. This gives us\n--\narch/s390/include/uapi/asm/kvm.h-348- */\narch/s390/include/uapi/asm/kvm.h:349:#define KVM_S390_MAX_FLOAT_IRQS\t266250\narch/s390/include/uapi/asm/kvm.h:350:#define KVM_S390_FLIC_MAX_BUFFER\t0x2000000\narch/s390/include/uapi/asm/kvm.h-351-\narch/s390/include/uapi/asm/kvm.h=352=struct kvm_s390_io_adapter {\n--\narch/s390/include/uapi/asm/kvm.h-359-\narch/s390/include/uapi/asm/kvm.h:360:#define KVM_S390_ADAPTER_SUPPRESSIBLE 0x01\narch/s390/include/uapi/asm/kvm.h-361-\n--\narch/s390/include/uapi/asm/kvm.h=367=struct kvm_s390_ais_all {\n--\narch/s390/include/uapi/asm/kvm.h-371-\narch/s390/include/uapi/asm/kvm.h:372:#define KVM_S390_IO_ADAPTER_MASK 1\narch/s390/include/uapi/asm/kvm.h:373:#define KVM_S390_IO_ADAPTER_MAP 2\narch/s390/include/uapi/asm/kvm.h:374:#define KVM_S390_IO_ADAPTER_UNMAP 3\narch/s390/include/uapi/asm/kvm.h-375-\narch/s390/include/uapi/asm/kvm.h=376=struct kvm_s390_io_adapter_req {\n--\narch/s390/include/uapi/asm/kvm.h-384-/* kvm attr_group  on vm fd */\narch/s390/include/uapi/asm/kvm.h:385:#define KVM_S390_VM_MEM_CTRL\t\t0\narch/s390/include/uapi/asm/kvm.h:386:#define KVM_S390_VM_TOD\t\t\t1\narch/s390/include/uapi/asm/kvm.h:387:#define KVM_S390_VM_CRYPTO\t\t2\narch/s390/include/uapi/asm/kvm.h:388:#define KVM_S390_VM_CPU_MODEL\t\t3\narch/s390/include/uapi/asm/kvm.h:389:#define KVM_S390_VM_MIGRATION\t\t4\narch/s390/include/uapi/asm/kvm.h:390:#define KVM_S390_VM_CPU_TOPOLOGY\t5\narch/s390/include/uapi/asm/kvm.h-391-\narch/s390/include/uapi/asm/kvm.h-392-/* kvm attributes for mem_ctrl */\narch/s390/include/uapi/asm/kvm.h:393:#define KVM_S390_VM_MEM_ENABLE_CMMA\t0\narch/s390/include/uapi/asm/kvm.h:394:#define KVM_S390_VM_MEM_CLR_CMMA\t1\narch/s390/include/uapi/asm/kvm.h:395:#define KVM_S390_VM_MEM_LIMIT_SIZE\t2\narch/s390/include/uapi/asm/kvm.h-396-\narch/s390/include/uapi/asm/kvm.h:397:#define KVM_S390_NO_MEM_LIMIT\t\tU64_MAX\narch/s390/include/uapi/asm/kvm.h-398-\narch/s390/include/uapi/asm/kvm.h:399:/* kvm attributes for KVM_S390_VM_TOD */\narch/s390/include/uapi/asm/kvm.h:400:#define KVM_S390_VM_TOD_LOW\t\t0\narch/s390/include/uapi/asm/kvm.h:401:#define KVM_S390_VM_TOD_HIGH\t\t1\narch/s390/include/uapi/asm/kvm.h:402:#define KVM_S390_VM_TOD_EXT\t\t2\narch/s390/include/uapi/asm/kvm.h-403-\narch/s390/include/uapi/asm/kvm.h=404=struct kvm_s390_vm_tod_clock {\n--\narch/s390/include/uapi/asm/kvm.h-408-\narch/s390/include/uapi/asm/kvm.h:409:/* kvm attributes for KVM_S390_VM_CPU_MODEL */\narch/s390/include/uapi/asm/kvm.h-410-/* processor related attributes are r/w */\narch/s390/include/uapi/asm/kvm.h:411:#define KVM_S390_VM_CPU_PROCESSOR\t0\narch/s390/include/uapi/asm/kvm.h-412-struct kvm_s390_vm_cpu_processor {\n--\narch/s390/include/uapi/asm/kvm.h-419-/* machine related attributes are r/o */\narch/s390/include/uapi/asm/kvm.h:420:#define KVM_S390_VM_CPU_MACHINE\t\t1\narch/s390/include/uapi/asm/kvm.h-421-struct kvm_s390_vm_cpu_machine {\n--\narch/s390/include/uapi/asm/kvm.h-428-\narch/s390/include/uapi/asm/kvm.h:429:#define KVM_S390_VM_CPU_PROCESSOR_FEAT\t2\narch/s390/include/uapi/asm/kvm.h:430:#define KVM_S390_VM_CPU_MACHINE_FEAT\t3\narch/s390/include/uapi/asm/kvm.h-431-\narch/s390/include/uapi/asm/kvm.h:432:#define KVM_S390_VM_CPU_FEAT_NR_BITS\t1024\narch/s390/include/uapi/asm/kvm.h:433:#define KVM_S390_VM_CPU_FEAT_ESOP\t0\narch/s390/include/uapi/asm/kvm.h:434:#define KVM_S390_VM_CPU_FEAT_SIEF2\t1\narch/s390/include/uapi/asm/kvm.h:435:#define KVM_S390_VM_CPU_FEAT_64BSCAO\t2\narch/s390/include/uapi/asm/kvm.h:436:#define KVM_S390_VM_CPU_FEAT_SIIF\t3\narch/s390/include/uapi/asm/kvm.h:437:#define KVM_S390_VM_CPU_FEAT_GPERE\t4\narch/s390/include/uapi/asm/kvm.h:438:#define KVM_S390_VM_CPU_FEAT_GSLS\t5\narch/s390/include/uapi/asm/kvm.h:439:#define KVM_S390_VM_CPU_FEAT_IB\t\t6\narch/s390/include/uapi/asm/kvm.h:440:#define KVM_S390_VM_CPU_FEAT_CEI\t7\narch/s390/include/uapi/asm/kvm.h:441:#define KVM_S390_VM_CPU_FEAT_IBS\t8\narch/s390/include/uapi/asm/kvm.h:442:#define KVM_S390_VM_CPU_FEAT_SKEY\t9\narch/s390/include/uapi/asm/kvm.h:443:#define KVM_S390_VM_CPU_FEAT_CMMA\t10\narch/s390/include/uapi/asm/kvm.h:444:#define KVM_S390_VM_CPU_FEAT_PFMFI\t11\narch/s390/include/uapi/asm/kvm.h:445:#define KVM_S390_VM_CPU_FEAT_SIGPIF\t12\narch/s390/include/uapi/asm/kvm.h:446:#define KVM_S390_VM_CPU_FEAT_KSS\t13\narch/s390/include/uapi/asm/kvm.h:447:#define KVM_S390_VM_CPU_FEAT_ASTFLEIE2\t14\narch/s390/include/uapi/asm/kvm.h-448-struct kvm_s390_vm_cpu_feat {\n--\narch/s390/include/uapi/asm/kvm.h-451-\narch/s390/include/uapi/asm/kvm.h:452:#define KVM_S390_VM_CPU_PROCESSOR_SUBFUNC\t4\narch/s390/include/uapi/asm/kvm.h:453:#define KVM_S390_VM_CPU_MACHINE_SUBFUNC\t\t5\narch/s390/include/uapi/asm/kvm.h-454-/* for \"test bit\" instructions MSB 0 bit ordering, for \"query\" raw blocks */\narch/s390/include/uapi/asm/kvm.h=455=struct kvm_s390_vm_cpu_subfunc {\n--\n\n"
}

							input: 31124
							output: 38
							thoughts: 25

Here's my take on the thought process, as if I were the one thinking it:

**Examining Kconfig for s390 KVM Configuration**

Okay, time to get to the heart of the matter. I need to understand how KVM is configured for the s390 architecture. Given my deep knowledge of kernel configuration, the logical first step is to delve into the `arch/s390/kvm/Kconfig` file. That's where I expect to find all the relevant `Kconfig` definitions. It'll show me the options, dependencies, and default settings that govern KVM's behavior on that specific platform. Understanding these configuration knobs is crucial for any further work I need to do on this aspect of the system. Let's see what's in there.

{
  "File": "arch/s390/kvm/Kconfig",
  "FirstLine": 1,
  "LineCount": 60
}

{
  "Contents": "   1:\t# SPDX-License-Identifier: GPL-2.0\n   2:\t#\n   3:\t# KVM configuration\n   4:\t#\n   5:\tsource \"virt/kvm/Kconfig\"\n   6:\t\n   7:\tmenuconfig VIRTUALIZATION\n   8:\t\tdef_bool y\n   9:\t\tprompt \"KVM\"\n  10:\t\thelp\n  11:\t\t  Say Y here to get to see options for using your Linux host to run other\n  12:\t\t  operating systems inside virtual machines (guests).\n  13:\t\t  This option alone does not add any kernel code.\n  14:\t\n  15:\t\t  If you say N, all options in this submenu will be skipped and disabled.\n  16:\t\n  17:\tif VIRTUALIZATION\n  18:\t\n  19:\tconfig KVM\n  20:\t\tdef_tristate y\n  21:\t\tprompt \"Kernel-based Virtual Machine (KVM) support\"\n  22:\t\tselect HAVE_KVM_CPU_RELAX_INTERCEPT\n  23:\t\tselect KVM_ASYNC_PF\n  24:\t\tselect KVM_ASYNC_PF_SYNC\n  25:\t\tselect KVM_COMMON\n  26:\t\tselect HAVE_KVM_IRQCHIP\n  27:\t\tselect HAVE_KVM_IRQ_ROUTING\n  28:\t\tselect HAVE_KVM_INVALID_WAKEUPS\n  29:\t\tselect HAVE_KVM_NO_POLL\n  30:\t\tselect KVM_VFIO\n  31:\t\tselect VIRT_XFER_TO_GUEST_WORK\n  32:\t\tselect KVM_MMU_LOCKLESS_AGING\n  33:\t\tselect KVM_GENERIC_PRE_FAULT_MEMORY\n  34:\t\thelp\n  35:\t\t  Support hosting paravirtualized guest machines using the SIE\n  36:\t\t  virtualization capability on the mainframe. This should work\n  37:\t\t  on any 64bit machine.\n  38:\t\n  39:\t\t  This module provides access to the hardware capabilities through\n  40:\t\t  a character device node named /dev/kvm.\n  41:\t\n  42:\t\t  To compile this as a module, choose M here: the module\n  43:\t\t  will be called kvm.\n  44:\t\n  45:\t\t  If unsure, say N.\n  46:\t\n  47:\tconfig KVM_S390_UCONTROL\n  48:\t\tbool \"Userspace controlled virtual machines\"\n  49:\t\tdepends on KVM\n  50:\t\thelp\n  51:\t\t  Allow CAP_SYS_ADMIN users to create KVM virtual machines that are\n  52:\t\t  controlled by userspace.\n  53:\t\n  54:\t\t  If unsure, say N.\n  55:\t\n  56:\tendif # VIRTUALIZATION\n"
}

							input: 32086
							output: 31
							thoughts: 1126

**Analyzing a KVM Patch for Fuzzing Potential**

Okay, so we're looking at a patch related to `VIRTUALIZATION` and specifically `KVM`. My initial thought is to determine if this is worth fuzzing. I need to quickly assess the nature of the changes.

Let's dive in and review the diff. It seems we have several file modifications across `arch/s390/kvm/s390/`. The changes appear to be mainly concerned with memory allocation and deallocation:

1. `handle_sthyi` is changing `get_zeroed_page` to `kzalloc`, and `free_page` to `kfree`.
2. `kvm_s390_gib_destroy` and `kvm_s390_gib_init` have similar changes, using `kzalloc` instead of `get_zeroed_page` and `kfree` instead of `free_page`.
3. `handle_stsi` also reflects this pattern of switching from `get_zeroed_page` and `free_page` to `kzalloc` and `kfree`.
4. `kvm_arch_init_vm` and `kvm_s390_vcpu_setup_cmma` are doing the same memory management changes.

Now, the critical question: Is this WorthFuzzing? I need to apply my knowledge of what makes a patch a good candidate for fuzzing. The guidelines are pretty clear. It's a "no" if it's purely documentation, decorative changes, or unreachable code paths in virtualized environments, particularly those relying on software emulation, like QEMU.

But this patch clearly modifies `arch/s390` KVM code! A core architecture component. So, my instinct is that this is potentially interesting. But I must be sure. I need to be sure this is a code path I can even execute! I need to determine if KVM on s390 can be run and fuzzed.

My immediate thought is: Can s390 KVM *run* in QEMU? And *why* does QEMU matter? The guidelines mention virtualized environments like QEMU. This seems central to the determination.

I recall that s390 KVM is used when Linux s390 is running with KVM. But what about QEMU? I know QEMU supports s390x using TCG, but doesn't the TCG implementation on s390x *not* support nested virtualization, particularly the SIE (System Instruction Extension) instruction set? Isn't SIE essential for KVM?

Then I realize I need to confirm: Does QEMU TCG s390x support KVM? I need to check something like `arch/s390/kvm/s390/sie.S` or SIE instructions in s390. This is the crux of the matter. If s390 KVM relies on SIE, and QEMU's TCG lacks SIE support, then this patch is unfortunately *not* fuzzable under standard QEMU. But I should check the implementation of SIE itself.

{
  "Expression": "sie64a",
  "PathPrefix": "arch/s390/"
}

{
  "Output": "arch/s390/include/asm/kvm_host_s390.h=683=void kvm_arch_crypto_set_masks(struct kvm *kvm, unsigned long *apm,\n--\narch/s390/include/asm/kvm_host_s390.h-688-\narch/s390/include/asm/kvm_host_s390.h:689:int __sie64a(phys_addr_t sie_block_phys, struct kvm_s390_sie_block *sie_block, u64 *rsa,\narch/s390/include/asm/kvm_host_s390.h-690-\t     unsigned long gasce);\narch/s390/include/asm/kvm_host_s390.h-691-\narch/s390/include/asm/kvm_host_s390.h:692:static inline int sie64a(struct kvm_s390_sie_block *sie_block, u64 *rsa, unsigned long gasce)\narch/s390/include/asm/kvm_host_s390.h-693-{\narch/s390/include/asm/kvm_host_s390.h:694:\treturn __sie64a(virt_to_phys(sie_block), sie_block, rsa, gasce);\narch/s390/include/asm/kvm_host_s390.h-695-}\n--\narch/s390/kernel/entry.S=184=EXPORT_SYMBOL(__WARN_trap)\n--\narch/s390/kernel/entry.S-189-/*\narch/s390/kernel/entry.S:190: * __sie64a calling convention:\narch/s390/kernel/entry.S-191- * %r2 pointer to sie control block phys\n--\narch/s390/kernel/entry.S-195- */\narch/s390/kernel/entry.S:196:SYM_FUNC_START(__sie64a)\narch/s390/kernel/entry.S-197-\tstmg\t%r6,%r14,__SF_GPRS(%r15)\t# save kernel registers\n--\narch/s390/kernel/entry.S=231=SYM_INNER_LABEL(sie_exit, SYM_L_GLOBAL)\n--\narch/s390/kernel/entry.S-242-\tBR_EX\t%r14\narch/s390/kernel/entry.S:243:SYM_FUNC_END(__sie64a)\narch/s390/kernel/entry.S:244:EXPORT_SYMBOL(__sie64a)\narch/s390/kernel/entry.S-245-EXPORT_SYMBOL(sie_exit)\n--\narch/s390/kernel/nmi.c=333=static void notrace s390_backup_mcck_info(struct pt_regs *regs)\n--\narch/s390/kernel/nmi.c-337-\narch/s390/kernel/nmi.c:338:\t/* r14 contains the sie block, which was set in sie64a */\narch/s390/kernel/nmi.c-339-\tstruct kvm_s390_sie_block *sie_block = phys_to_virt(regs-\u003egprs[14]);\n--\narch/s390/kernel/traps.c=338=void noinstr __do_pgm_check(struct pt_regs *regs, unsigned long flags)\n--\narch/s390/kernel/traps.c-356-\t * In case of a guest fault, short-circuit the fault handler and return.\narch/s390/kernel/traps.c:357:\t * This way the sie64a() function will return 0; fault address and\narch/s390/kernel/traps.c-358-\t * other relevant bits are saved in current-\u003ethread.gmap_teid, and\n--\narch/s390/kvm/s390/s390.c=4748=int noinstr kvm_s390_enter_exit_sie(struct kvm_s390_sie_block *scb,\n--\narch/s390/kvm/s390/s390.c-4759-\t */\narch/s390/kvm/s390/s390.c:4760:\tret = sie64a(scb, gprs, gasce);\narch/s390/kvm/s390/s390.c-4761-\n--\narch/s390/kvm/s390/vsie.c=1187=static int do_vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page, struct gmap *sg)\n--\narch/s390/kvm/s390/vsie.c-1214-\t/*\narch/s390/kvm/s390/vsie.c:1215:\t * Simulate a SIE entry of the VCPU (see sie64a), so VCPU blocking\narch/s390/kvm/s390/vsie.c-1216-\t * and VCPU requests also hinder the vSIE from running and lead\n"
}

							input: 35349
							output: 37
							thoughts: 570

**My Fuzzing Assessment**

Okay, wait a minute! Syzkaller *does* target s390x! Right, Linux/s390x is supported. This is interesting. Let's delve into the specific functions: `kvm_arch_init_vm`, `handle_sthyi`, `handle_stsi`, and `kvm_s390_vcpu_setup_cmma`. Are these functions actually *reachable* when running Syzkaller on s390x?

Yes, confirmed. The `KVM_CREATE_VM` ioctl calls `kvm_arch_init_vm` on s390x. And `KVM_RUN` handles exits and intercepts, specifically calling `handle_sthyi` and `handle_stsi`. Furthermore, `kvm_s390_vcpu_setup_cmma` gets called during CMMA setup, and `kvm_s390_gib_init` happens during module initialization.

The key question: is this functional change *worth* fuzzing? Let's go through the checklist.

The criteria say to return `WorthFuzzing=false` if the patch only contains modifications to documentation, Kconfig files, or code comments; purely decorative changes like logging or tracepoints; changes to numeric constants/macros that don't alter execution flow; unreachable code paths in virtualized environments; vendor-specific PCIe switch, SmartNIC, or GPU driver code that requires physical hardware; or driver teardown callbacks that are only executed during PCI hot-unplug or sysfs driver unbind operations.

None of those exclusion criteria apply here! This looks good!

Okay, according to the guidelines, "If it modifies reachable core kernel logic, drivers, or architectures, use your code search tools to verify the code can be executed, then return WorthFuzzing=true."

Alright, let's verify what `FocusSymbols` and `EnableConfigs` to return.

First let's look at the modified functions:
1.  `handle_sthyi` (in arch/s390/kvm/s390/intercept.c) - *This* is a key one. It's a non-static function! Let's check `intercept.c` more closely...

{
  "Expression": "int handle_sthyi\\(",
  "PathPrefix": "arch/s390/kvm/"
}

{
  "Output": "arch/s390/kvm/s390/intercept.c=396=static int handle_partial_execution(struct kvm_vcpu *vcpu)\n--\narch/s390/kvm/s390/intercept.c-412- */\narch/s390/kvm/s390/intercept.c:413:int handle_sthyi(struct kvm_vcpu *vcpu)\narch/s390/kvm/s390/intercept.c-414-{\n--\narch/s390/kvm/s390/s390.h=421=static inline void kvm_s390_retry_instr(struct kvm_vcpu *vcpu)\n--\narch/s390/kvm/s390/s390.h-427-\narch/s390/kvm/s390/s390.h:428:int handle_sthyi(struct kvm_vcpu *vcpu);\narch/s390/kvm/s390/s390.h-429-\n"
}

							input: 36752
							output: 34
							thoughts: 44

Here's my summary, as though I'm thinking through this process:

**Diving into the `handle_stsi` Function**

Okay, time to get to the bottom of this. I need to understand `handle_stsi` in the s390 KVM architecture. Let's see, the file is `arch/s390/kvm/s390/priv.c`. Now, the key question is, and this is crucial for how it's used, is `handle_stsi` declared as `static` or non-static? That will dictate its scope and how it's actually accessed within the broader KVM framework. I need to check its declaration to ascertain its visibility and intended usage. This is going to be important to understand how it interfaces with the other parts of the s390 architecture.

{
  "Expression": "handle_stsi",
  "PathPrefix": "arch/s390/kvm/"
}

{
  "Output": "arch/s390/kvm/s390/priv.c=805=static int handle_stidp(struct kvm_vcpu *vcpu)\n--\narch/s390/kvm/s390/priv.c-829-\narch/s390/kvm/s390/priv.c:830:static void handle_stsi_3_2_2(struct kvm_vcpu *vcpu, struct sysinfo_3_2_2 *mem)\narch/s390/kvm/s390/priv.c-831-{\n--\narch/s390/kvm/s390/priv.c=857=static void insert_stsi_usr_data(struct kvm_vcpu *vcpu, u64 addr, u8 ar,\n--\narch/s390/kvm/s390/priv.c-867-\narch/s390/kvm/s390/priv.c:868:static int handle_stsi(struct kvm_vcpu *vcpu)\narch/s390/kvm/s390/priv.c-869-{\n--\narch/s390/kvm/s390/priv.c-926-\t\t\tgoto out_no_data;\narch/s390/kvm/s390/priv.c:927:\t\thandle_stsi_3_2_2(vcpu, mem);\narch/s390/kvm/s390/priv.c-928-\t\tbreak;\n--\narch/s390/kvm/s390/priv.c-930-\t\tinsert_stsi_usr_data(vcpu, operand2, ar, fc, sel1, sel2);\narch/s390/kvm/s390/priv.c:931:\t\ttrace_kvm_s390_handle_stsi(vcpu, fc, sel1, sel2, operand2);\narch/s390/kvm/s390/priv.c-932-\t\treturn -EREMOTE;\n--\narch/s390/kvm/s390/priv.c-947-\t}\narch/s390/kvm/s390/priv.c:948:\ttrace_kvm_s390_handle_stsi(vcpu, fc, sel1, sel2, operand2);\narch/s390/kvm/s390/priv.c-949-\tkfree(mem);\n--\narch/s390/kvm/s390/priv.c=960=int kvm_s390_handle_b2(struct kvm_vcpu *vcpu)\n--\narch/s390/kvm/s390/priv.c-1005-\tcase 0x7d:\narch/s390/kvm/s390/priv.c:1006:\t\treturn handle_stsi(vcpu);\narch/s390/kvm/s390/priv.c-1007-\tcase 0xaf:\n--\narch/s390/kvm/s390/trace.h=387=TRACE_EVENT(kvm_s390_handle_stfl,\n--\narch/s390/kvm/s390/trace.h-404-\narch/s390/kvm/s390/trace.h:405:TRACE_EVENT(kvm_s390_handle_stsi,\narch/s390/kvm/s390/trace.h-406-\t    TP_PROTO(VCPU_PROTO_COMMON, int fc, int sel1, int sel2, u64 addr),\n"
}

							input: 37987
							output: 45
							thoughts: 264

**My Analysis of KVM/s390 Code Changes**

Okay, so `kvm_s390_handle_b2` calls `handle_stsi`, and I'm diving into the recent modifications. First, let's confirm that `kvm_s390_handle_b2` isn't static, which it isn't. Good. Now, I want to review all the functions that have been touched as a result of this change.

Here's the list I've compiled:

1.  `handle_sthyi` is non-static, which is relevant.
2.  `kvm_s390_gib_init` and `kvm_s390_gib_destroy` are non-static, though the init is marked as `__init`, so it's probably not a big concern here.
3.  `handle_stsi`, obviously, since it's called by `kvm_s390_handle_b2` and is also non-static.
4.  `kvm_arch_init_vm` and `kvm_arch_destroy_vm` are non-static as well. This makes me curious about the overall VM lifecycle.
5.  `kvm_s390_vcpu_setup_cmma` and `kvm_s390_vcpu_unsetup_cmma` are also non-static and warrant some investigation.

Now, I'm going to take a closer look at `kvm_s390_vcpu_setup_cmma` – I'll go to `arch/s390/kvm/s390/s390.c` to examine its implementation and see what's going on there.

{
  "Expression": "kvm_s390_vcpu_setup_cmma",
  "PathPrefix": "arch/s390/kvm/"
}

{
  "Output": "arch/s390/kvm/s390/s390.c=3657=void kvm_s390_vcpu_unsetup_cmma(struct kvm_vcpu *vcpu)\n--\narch/s390/kvm/s390/s390.c-3663-\narch/s390/kvm/s390/s390.c:3664:int kvm_s390_vcpu_setup_cmma(struct kvm_vcpu *vcpu)\narch/s390/kvm/s390/s390.c-3665-{\n--\narch/s390/kvm/s390/s390.c=3684=static int kvm_s390_vcpu_setup(struct kvm_vcpu *vcpu)\n--\narch/s390/kvm/s390/s390.c-3746-\tif (vcpu-\u003ekvm-\u003earch.use_cmma) {\narch/s390/kvm/s390/s390.c:3747:\t\trc = kvm_s390_vcpu_setup_cmma(vcpu);\narch/s390/kvm/s390/s390.c-3748-\t\tif (rc)\n--\narch/s390/kvm/s390/s390.h=465=void kvm_s390_sync_request(int req, struct kvm_vcpu *vcpu);\narch/s390/kvm/s390/s390.h:466:int kvm_s390_vcpu_setup_cmma(struct kvm_vcpu *vcpu);\narch/s390/kvm/s390/s390.h-467-void kvm_s390_vcpu_unsetup_cmma(struct kvm_vcpu *vcpu);\n"
}

							input: 39221
							output: 38
							thoughts: 49

Okay, let's dive into this. I need to get a handle on the lifecycle of a KVM virtual machine, specifically on the s390 architecture. My initial thought is to zero in on the core functions responsible for initialization and destruction. So, I'm thinking, let's dissect `kvm_arch_init_vm` and `kvm_arch_destroy_vm`. I'll be looking at how they're implemented, what resources they allocate and deallocate, and how they interact with the s390-specific architectural components within the KVM framework. I'm heading straight to `arch/s390/kvm/s390/s390.c`. This should give me a solid understanding of the virtual machine's entry and exit points on this particular architecture.

{
  "Expression": "kvm_arch_init_vm",
  "PathPrefix": "arch/s390/kvm/"
}

{
  "Output": "arch/s390/kvm/s390/s390.c=3232=void kvm_arch_free_vm(struct kvm *kvm)\n--\narch/s390/kvm/s390/s390.c-3239-\narch/s390/kvm/s390/s390.c:3240:int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)\narch/s390/kvm/s390/s390.c-3241-{\n"
}

							input: 39647
							output: 40
							thoughts: 52

Here's my summary, as if I were thinking these thoughts:

**Examining KVM/s390 GIB Initialization and Destruction**

Okay, time to dig into interrupt handling within the KVM/s390 architecture. I'm specifically interested in how Global Interrupt Blocks, or GIBs, are handled. Let's start by looking at `kvm_s390_gib_init` and `kvm_s390_gib_destroy` functions. They should be the key to understanding the allocation, setup, and cleanup of these GIB structures. I'll find them within `arch/s390/kvm/s390/interrupt.c`. This is where the core logic for managing these interrupts should reside, so these functions are likely to provide the details I need. Let's see how they work.

{
  "Expression": "kvm_s390_gib_",
  "PathPrefix": "arch/s390/kvm/"
}

{
  "Output": "arch/s390/kvm/s390/interrupt.c=3677=static struct airq_struct gib_alert_irq = {\n--\narch/s390/kvm/s390/interrupt.c-3680-\narch/s390/kvm/s390/interrupt.c:3681:void kvm_s390_gib_destroy(void)\narch/s390/kvm/s390/interrupt.c-3682-{\n--\narch/s390/kvm/s390/interrupt.c-3695-\narch/s390/kvm/s390/interrupt.c:3696:int __init kvm_s390_gib_init(u8 nisc)\narch/s390/kvm/s390/interrupt.c-3697-{\n--\narch/s390/kvm/s390/s390.c=496=static int __init __kvm_s390_init(void)\n--\narch/s390/kvm/s390/s390.c-528-\narch/s390/kvm/s390/s390.c:529:\trc = kvm_s390_gib_init(GAL_ISC);\narch/s390/kvm/s390/s390.c-530-\tif (rc)\n--\narch/s390/kvm/s390/s390.c=550=static void __kvm_s390_exit(void)\n--\narch/s390/kvm/s390/s390.c-554-\narch/s390/kvm/s390/s390.c:555:\tkvm_s390_gib_destroy();\narch/s390/kvm/s390/s390.c-556-\tif (IS_ENABLED(CONFIG_VFIO_PCI_ZDEV_KVM))\n--\narch/s390/kvm/s390/s390.h=564=void kvm_s390_gisa_enable(struct kvm *kvm);\narch/s390/kvm/s390/s390.h:565:int __init kvm_s390_gib_init(u8 nisc);\narch/s390/kvm/s390/s390.h:566:void kvm_s390_gib_destroy(void);\narch/s390/kvm/s390/s390.h-567-void kvm_s390_unmap_all_adapters(struct kvm *kvm);\n"
}

							input: 40667
							output: 37
							thoughts: 23

Here's my summary, as though I'm thinking through this process:

**Diving into KVM for s390 Architecture**

Alright, time to get my hands dirty. I'm going to start by taking a close look at the build configuration for KVM, specifically for the s390 architecture. First things first, let's navigate to the `arch/s390/kvm/` directory. I need to understand how this all fits together. I'm thinking the `Makefile` in there will give me the lowdown on the build process for the KVM components specific to the s390 architecture. That's usually the best place to start. Then, I'll need to scrutinize the `Kconfig` dependencies to see which features are enabled, what options are available, and how everything is interconnected from a configuration perspective. I want to see if there are any subtle dependencies or potential conflicts that I need to be aware of. This should give me a solid foundation for understanding the s390 KVM build process and any related issues or modifications I might want to make.

{
  "File": "arch/s390/kvm/Makefile",
  "FirstLine": 1,
  "LineCount": 50
}

{
  "Contents": "   1:\t# SPDX-License-Identifier: GPL-2.0\n   2:\t# Makefile for kernel virtual machines on s390\n   3:\t#\n   4:\t# Copyright IBM Corp. 2008\n   5:\t\n   6:\tobj-$(CONFIG_KVM) += s390/\n"
}

							input: 41053
							output: 42
							thoughts: 22

Here's my summary, as though I'm thinking through this process:

**Diving into the S390 KVM Makefile**

Okay, time to get my hands dirty with the s390 KVM code. I need to understand how the build process is structured for that architecture. Let's start with the `Makefile` located in `arch/s390/kvm/s390/`. This is the logical starting point – the build scripts are often the best place to gain a high-level overview of a project. I'm hoping to quickly identify the key components, their dependencies, and any architecture-specific flags or settings being used for the s390 KVM implementation. I'll be looking for things like: how the core KVM modules are compiled, any custom object files, any specific include paths, and any link flags. I’m also interested in how it handles specific features or optimizations for the s390 architecture. This `Makefile` should provide a good jumping-off point for deeper investigation. Let’s see what's in there.

{
  "File": "arch/s390/kvm/s390/Makefile",
  "FirstLine": 1,
  "LineCount": 50
}

{
  "Contents": "   1:\t# SPDX-License-Identifier: GPL-2.0\n   2:\t\n   3:\tKVM := ../../../../virt/kvm\n   4:\tinclude $(srctree)/virt/kvm/Makefile.kvm\n   5:\tinclude $(srctree)/arch/s390/kvm/gmap/Makefile\n   6:\t\n   7:\tccflags-y := -I$(src) -I$(srctree)/arch/s390/kvm/gmap\n   8:\t\n   9:\tkvm-y += s390.o intercept.o interrupt.o priv.o sigp.o\n  10:\tkvm-y += diag.o gaccess.o guestdbg.o vsie.o pv.o\n  11:\tkvm-y += $(gmap-y)\n  12:\t\n  13:\tkvm-$(CONFIG_VFIO_PCI_ZDEV_KVM) += pci.o\n  14:\tobj-$(CONFIG_KVM) += kvm.o\n"
}

							input: 41612
							output: 184
							thoughts: 757

**My Analysis of KVM Configuration and Relevant Symbols**

Okay, so I'm diving into this KVM-related patch. My initial thought is to zero in on `CONFIG_KVM` as the primary configuration option. I need to understand the dependencies and how this is all wired up, so I started by checking `arch/s390/Kconfig` and `virt/kvm/Kconfig` to see if there are any other related configs I need to consider.

Within `arch/s390/kvm/Kconfig`, I found the `VIRTUALIZATION` menu and the `KVM` config, which depends on `VIRTUALIZATION`. I need to figure out the interplay between these. I'm trying to decide if I need both `VIRTUALIZATION` *and* `KVM`, or if enabling `KVM` implicitly handles `VIRTUALIZATION`, or perhaps if it's the other way around. I'm trying to understand the dependencies.

Next, I turned my attention to the key symbols involved in this patch to see how they're connected. I identified a few key ones: `handle_sthyi` (which handles the STHYI instruction intercept), `kvm_s390_handle_b2` (which handles B2 instruction intercepts, including STSI through `handle_stsi`), `kvm_arch_init_vm` (which initializes s390 VM architecture structures including sie_page2), and `kvm_s390_vcpu_setup_cmma` (which sets up CMMA CBR/CBRLE structures).

I checked the static/non-static nature of these symbols to see how they are exposed, and if any are internal details only. Specifically, I noted that `handle_stsi` is static, defined in `arch/s390/kvm/s390/priv.c`, but it's called by the non-static `kvm_s390_handle_b2`. The rest are non-static.

Finally, I reviewed the patch diff itself to confirm the files and symbols involved. The patch touches `arch/s390/kvm/s390/intercept.c` (where `handle_sthyi` lives), `arch/s390/kvm/s390/interrupt.c` (with `kvm_s390_gib_init` and `kvm_s390_gib_destroy`), `arch/s390/kvm/s390/priv.c` (where `handle_stsi` is defined and called), and `arch/s390/kvm/s390/s390.c` (with `kvm_arch_init_vm`, `kvm_arch_destroy_vm`, `kvm_s390_vcpu_setup_cmma`, and `kvm_s390_vcpu_unsetup_cmma`). This solidifies my understanding of the relevant modules and functions.

So, to summarize, the focus symbols are `handle_sthyi`, `kvm_s390_handle_b2`, `kvm_arch_init_vm`, and `kvm_s390_vcpu_setup_cmma`. The relevant configs are `KVM` and `VIRTUALIZATION`. Time to call `set-results`.

{
  "EnableConfigs": [
    "KVM",
    "VIRTUALIZATION"
  ],
  "FocusSymbols": [
    "handle_sthyi",
    "kvm_s390_handle_b2",
    "kvm_arch_init_vm",
    "kvm_s390_vcpu_setup_cmma"
  ],
  "Reasoning": "The patch changes page-level memory allocations (get_zeroed_page/free_page) to slab allocations (kzalloc/kfree) in KVM on s390 for guest intercept handling (STHYI, STSI), VM initialization (sie_page2), GIB setup, and VCPU CMMA setup. These affect reachable KVM execution paths and memory management on s390, making it worth fuzzing.",
  "WorthFuzzing": true
}

{
  "EnableConfigs": [
    "KVM",
    "VIRTUALIZATION"
  ],
  "FocusSymbols": [
    "handle_sthyi",
    "kvm_s390_handle_b2",
    "kvm_arch_init_vm",
    "kvm_s390_vcpu_setup_cmma"
  ],
  "Reasoning": "The patch changes page-level memory allocations (get_zeroed_page/free_page) to slab allocations (kzalloc/kfree) in KVM on s390 for guest intercept handling (STHYI, STSI), VM initialization (sie_page2), GIB setup, and VCPU CMMA setup. These affect reachable KVM execution paths and memory management on s390, making it worth fuzzing.",
  "WorthFuzzing": true
}

{
  "WorthFuzzing": true
}

{
  "KMSANReasoning": "The patch converts page allocations via get_zeroed_page() and free_page() to slab allocations via kzalloc()/kzalloc_obj() and kfree() across s390 KVM code (intercept.c, interrupt.c, priv.c, s390.c). \n\nSince kzalloc/kzalloc_obj zero-initializes the memory identically to get_zeroed_page(), no uninitialized memory usage, conditional branches on uninitialized data, or uninitialized info-leaks to userspace/guest are introduced. Any potential slab-related memory safety issues (e.g. out-of-bounds, use-after-free, or double-free) are monitored by standard KASAN. Thus, a dedicated KMSAN fuzzing session is not required.",
  "NeedsKMSAN": false
}

You are an expert Linux kernel security engineer specializing in kernel memory
error detectors (KASAN and KMSAN). Your job is to review the provided patch series and
determine if the code changes justify spawning a dedicated KMSAN (KernelMemorySanitizer)
fuzzing session in addition to standard KASAN fuzzing.

CRITICAL DISTINCTION BETWEEN KASAN AND KMSAN:
- Standard KASAN kernel builds (upstream-apparmor-kasan.config) already enable
  a comprehensive suite of debugging tools and sanitizers, including KASAN
  (out-of-bounds accesses, use-after-free, double free, invalid free), LOCKDEP
  (locking bugs and deadlocks), UB-sanitizers, and memory corruption checks.
- KMSAN (KernelMemorySanitizer) detects reads of UNINITIALIZED memory (stack, heap,
  or page allocations) and kernel-to-user memory info-leaks.

Rule: THERE IS NO SENSE IN RUNNING A KMSAN SESSION IF A BUG CAN BE CAUGHT BY KASAN,
LOCKDEP, OR OTHER STANDARD BUG DETECTORS.
A dedicated KMSAN fuzzing session incurs significant resource costs. You must ONLY
set NeedsKMSAN=true if the code changes introduce or expose UNINITIALIZED MEMORY risks
that are detected ONLY by KMSAN.

Look holistically at the patch series and surrounding code. Even if no direct
uninitialized field accesses or new buffer allocations are added in the diff itself,
a patch may alter control flow, bounds checking, or data length calculations in ways
that change how the rest of the code operates on existing buffers (e.g. allowing
uninitialized stack/heap memory to be read, copied to user space, or used in control
flow). Do not hesitate to use your code access tools to inspect the surrounding code,
called functions, and callers.

Set NeedsKMSAN=true ONLY IF the patch introduces or modifies:
1. Kernel structures sent to user space (via copy_to_user, put_user, netlink skb
   attributes, ioctl output arguments, socket options, or BPF buffers) where fields
   or structure padding might not be fully initialized/zeroed.
2. Conditional logic or branching that depends on potentially uninitialized variables
   or struct fields.
3. Allocation or initialization of complex data structures where uninitialized fields
   could be read later in reachable code paths.
4. Bounds checks, lengths, or logic in a way that allows surrounding code to access
   uninitialized bytes of existing buffers.

Set NeedsKMSAN=false IF:
- The code changes primarily risk out-of-bounds access, array overflows, NULL pointer
  dereferences, locking deadlocks, or use-after-free bugs (these are already caught
  by KASAN, LOCKDEP, or standard bug detectors).
- All stack/heap structures touched or introduced by the patch are fully zeroed
  or initialized (e.g. using = {0}, memset, kzalloc) before being read or copied.
- The patch does not introduce any risk of uninitialized memory usage or info-leaks.

Use your code access tools to inspect the surrounding code if necessary, then provide
detailed KMSANReasoning contrasting KASAN vs KMSAN applicability for this patch.
Prefer calling several tools at the same time to save round-trips.


Use set-results tool to provide results of the analysis.
It must be called exactly once before the final reply.
Ignore results of this tool.

For your convenience, here is the diff of the changes:
commit d6dfce07c89aeb7d6cbdec8c5ab5c85f2699366d
Author: syz-cluster <triage@syzkaller.com>
Date:   Wed Sep 2 19:02:54 2026 +0000

    syz-cluster: applied patch under review

diff --git a/arch/s390/kvm/s390/intercept.c b/arch/s390/kvm/s390/intercept.c
index ca1205dfac8b0..aaf9828d1f44d 100644
--- a/arch/s390/kvm/s390/intercept.c
+++ b/arch/s390/kvm/s390/intercept.c
@@ -11,6 +11,7 @@
 #include <linux/kvm_host.h>
 #include <linux/errno.h>
 #include <linux/pagemap.h>
+#include <linux/slab.h>
 
 #include <asm/asm-offsets.h>
 #include <asm/irq.h>
@@ -438,13 +439,13 @@ int handle_sthyi(struct kvm_vcpu *vcpu)
 	if (!kvm_s390_pv_cpu_is_protected(vcpu) && (addr & ~PAGE_MASK))
 		return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
 
-	sctns = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT);
+	sctns = kzalloc(PAGE_SIZE, GFP_KERNEL_ACCOUNT);
 	if (!sctns)
 		return -ENOMEM;
 
 	cc = sthyi_fill(sctns, &rc);
 	if (cc < 0) {
-		free_page((unsigned long)sctns);
+		kfree(sctns);
 		return cc;
 	}
 out:
@@ -454,13 +455,13 @@ int handle_sthyi(struct kvm_vcpu *vcpu)
 		} else {
 			r = write_guest(vcpu, addr, reg2, sctns, PAGE_SIZE);
 			if (r) {
-				free_page((unsigned long)sctns);
+				kfree(sctns);
 				return kvm_s390_inject_prog_cond(vcpu, r);
 			}
 		}
 	}
 
-	free_page((unsigned long)sctns);
+	kfree(sctns);
 	vcpu->run->s.regs.gprs[reg2 + 1] = rc;
 	kvm_s390_set_psw_cc(vcpu, cc);
 	return r;
diff --git a/arch/s390/kvm/s390/interrupt.c b/arch/s390/kvm/s390/interrupt.c
index 0381ae9817035..02065fb8d053e 100644
--- a/arch/s390/kvm/s390/interrupt.c
+++ b/arch/s390/kvm/s390/interrupt.c
@@ -3689,7 +3689,7 @@ void kvm_s390_gib_destroy(void)
 	}
 	chsc_sgib(0);
 	unregister_adapter_interrupt(&gib_alert_irq);
-	free_page((unsigned long)gib);
+	kfree(gib);
 	gib = NULL;
 }
 
@@ -3703,7 +3703,7 @@ int __init kvm_s390_gib_init(u8 nisc)
 		goto out;
 	}
 
-	gib = (struct kvm_s390_gib *)get_zeroed_page(GFP_KERNEL_ACCOUNT | GFP_DMA);
+	gib = kzalloc(PAGE_SIZE, GFP_KERNEL_ACCOUNT | GFP_DMA);
 	if (!gib) {
 		rc = -ENOMEM;
 		goto out;
@@ -3722,7 +3722,7 @@ int __init kvm_s390_gib_init(u8 nisc)
 	gib_origin = virt_to_phys(gib);
 	if (chsc_sgib(gib_origin)) {
 		pr_err("Associating the GIB with the AIV facility failed\n");
-		free_page((unsigned long)gib);
+		kfree(gib);
 		gib = NULL;
 		rc = -EIO;
 		goto out_unreg_gal;
@@ -3742,7 +3742,7 @@ int __init kvm_s390_gib_init(u8 nisc)
 out_unreg_gal:
 	unregister_adapter_interrupt(&gib_alert_irq);
 out_free_gib:
-	free_page((unsigned long)gib);
+	kfree(gib);
 	gib = NULL;
 out:
 	return rc;
diff --git a/arch/s390/kvm/s390/priv.c b/arch/s390/kvm/s390/priv.c
index b3cb2c2c3aa71..856939acf012f 100644
--- a/arch/s390/kvm/s390/priv.c
+++ b/arch/s390/kvm/s390/priv.c
@@ -14,6 +14,7 @@
 #include <linux/mm_types.h>
 #include <linux/pgtable.h>
 #include <linux/io.h>
+#include <linux/slab.h>
 #include <asm/asm-offsets.h>
 #include <asm/facility.h>
 #include <asm/current.h>
@@ -869,7 +870,7 @@ static int handle_stsi(struct kvm_vcpu *vcpu)
 	int fc = (vcpu->run->s.regs.gprs[0] & 0xf0000000) >> 28;
 	int sel1 = vcpu->run->s.regs.gprs[0] & 0xff;
 	int sel2 = vcpu->run->s.regs.gprs[1] & 0xffff;
-	unsigned long mem = 0;
+	void *mem = NULL;
 	u64 operand2;
 	int rc = 0;
 	u8 ar;
@@ -911,19 +912,19 @@ static int handle_stsi(struct kvm_vcpu *vcpu)
 	switch (fc) {
 	case 1: /* same handling for 1 and 2 */
 	case 2:
-		mem = get_zeroed_page(GFP_KERNEL_ACCOUNT);
+		mem = kzalloc(PAGE_SIZE, GFP_KERNEL_ACCOUNT);
 		if (!mem)
 			goto out_no_data;
-		if (stsi((void *) mem, fc, sel1, sel2))
+		if (stsi(mem, fc, sel1, sel2))
 			goto out_no_data;
 		break;
 	case 3:
 		if (sel1 != 2 || sel2 != 2)
 			goto out_no_data;
-		mem = get_zeroed_page(GFP_KERNEL_ACCOUNT);
+		mem = kzalloc(PAGE_SIZE, GFP_KERNEL_ACCOUNT);
 		if (!mem)
 			goto out_no_data;
-		handle_stsi_3_2_2(vcpu, (void *) mem);
+		handle_stsi_3_2_2(vcpu, mem);
 		break;
 	case 15: /* fc 15 is fully handled in userspace */
 		insert_stsi_usr_data(vcpu, operand2, ar, fc, sel1, sel2);
@@ -931,10 +932,10 @@ static int handle_stsi(struct kvm_vcpu *vcpu)
 		return -EREMOTE;
 	}
 	if (kvm_s390_pv_cpu_is_protected(vcpu)) {
-		memcpy(sida_addr(vcpu->arch.sie_block), (void *)mem, PAGE_SIZE);
+		memcpy(sida_addr(vcpu->arch.sie_block), mem, PAGE_SIZE);
 		rc = 0;
 	} else {
-		rc = write_guest(vcpu, operand2, ar, (void *)mem, PAGE_SIZE);
+		rc = write_guest(vcpu, operand2, ar, mem, PAGE_SIZE);
 	}
 	if (rc) {
 		rc = kvm_s390_inject_prog_cond(vcpu, rc);
@@ -945,14 +946,14 @@ static int handle_stsi(struct kvm_vcpu *vcpu)
 		rc = -EREMOTE;
 	}
 	trace_kvm_s390_handle_stsi(vcpu, fc, sel1, sel2, operand2);
-	free_page(mem);
+	kfree(mem);
 	kvm_s390_set_psw_cc(vcpu, 0);
 	vcpu->run->s.regs.gprs[0] = 0;
 	return rc;
 out_no_data:
 	kvm_s390_set_psw_cc(vcpu, 3);
 out:
-	free_page(mem);
+	kfree(mem);
 	return rc;
 }
 
diff --git a/arch/s390/kvm/s390/s390.c b/arch/s390/kvm/s390/s390.c
index b0839e887221e..8ec505060f8c0 100644
--- a/arch/s390/kvm/s390/s390.c
+++ b/arch/s390/kvm/s390/s390.c
@@ -3273,8 +3273,8 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
 		goto out_err;
 
 	BUILD_BUG_ON(sizeof(struct sie_page2) != 4096);
-	kvm->arch.sie_page2 =
-	     (struct sie_page2 *) get_zeroed_page(GFP_KERNEL_ACCOUNT | GFP_DMA);
+	kvm->arch.sie_page2 = kzalloc_obj(*kvm->arch.sie_page2,
+					  GFP_KERNEL_ACCOUNT | GFP_DMA);
 	if (!kvm->arch.sie_page2)
 		goto out_err;
 
@@ -3369,7 +3369,7 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
 
 	return 0;
 out_err:
-	free_page((unsigned long)kvm->arch.sie_page2);
+	kfree(kvm->arch.sie_page2);
 	debug_unregister(kvm->arch.dbf);
 	sca_dispose(kvm);
 	KVM_EVENT(3, "creation of vm failed: %d", rc);
@@ -3427,7 +3427,7 @@ void kvm_arch_destroy_vm(struct kvm *kvm)
 		mmu_notifier_unregister(&kvm->arch.pv.mmu_notifier, kvm->mm);
 
 	debug_unregister(kvm->arch.dbf);
-	free_page((unsigned long)kvm->arch.sie_page2);
+	kfree(kvm->arch.sie_page2);
 	kvm_s390_destroy_adapters(kvm);
 	kvm_s390_clear_float_irqs(kvm);
 	kvm_s390_vsie_destroy(kvm);
@@ -3657,13 +3657,13 @@ static void kvm_s390_vcpu_crypto_setup(struct kvm_vcpu *vcpu)
 void kvm_s390_vcpu_unsetup_cmma(struct kvm_vcpu *vcpu)
 {
 	if (vcpu->arch.sie_block->cbrlo)
-		free_page((unsigned long)phys_to_virt(vcpu->arch.sie_block->cbrlo));
+		kfree(phys_to_virt(vcpu->arch.sie_block->cbrlo));
 	vcpu->arch.sie_block->cbrlo = 0;
 }
 
 int kvm_s390_vcpu_setup_cmma(struct kvm_vcpu *vcpu)
 {
-	void *cbrlo_page = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT);
+	void *cbrlo_page = kzalloc(PAGE_SIZE, GFP_KERNEL_ACCOUNT);
 
 	if (!cbrlo_page)
 		return -ENOMEM;

							input: 5142
							output: 18
							thoughts: 922

**Analyzing the Patch for Uninitialized Memory Risks**

Okay, let's dive into this patch and see if it introduces any uninitialized memory concerns that would warrant a KMSAN session. My first step is to examine the diff, which touches `arch/s390/kvm/s390/intercept.c`, `arch/s390/kvm/s390/interrupt.c`, `arch/s390/kvm/s390/priv.c`, and `arch/s390/kvm/s390/s390.c`.

Right off the bat, I see the pattern: it's replacing `get_zeroed_page()` and `free_page()` with `kzalloc()` and `kfree()`, or `kzalloc_obj` and `kfree()` in the case of `sie_page2`. The critical thing is that we're *still* zero-initializing the memory – the change is using `kzalloc` instead of `get_zeroed_page`, which is essentially a safe operation.

Now, the question is, are there any uninitialized memory risks *introduced* by these changes? No, because all the allocations are still zero-initialized. I've got to check whether any uninitialized memory is read, copied to userspace, or used in control flow, but, there is no such thing. Are there uninitialized struct fields, or leaks of information? Again, it doesn't seem like it.

It's actually a good thing in that KMSAN will probably catch out-of-bounds/use-after-free with slab allocations, whereas page allocations had page-level tracking. Because we're using zero-allocators (`kzalloc`), everything remains fully initialized.

Let me just do a quick scan to make sure I'm not missing something and double-check `kzalloc_obj(*kvm->arch.sie_page2, ...)`. I'll run a quick search for `kzalloc_obj` and `struct sie_page2` just to refresh my memory and be extra certain. Overall, it appears this patch is a straightforward and safe optimization, replacing the older allocation functions with the newer ones, which maintain the desired zero-initialization behavior. No KMSAN session necessary here.

{
  "Expression": "kzalloc_obj"
}

{
  "Output": "\nFull output is too long, showing 500 out of 79378 lines.\nUse more precise expression if possible.\n\nDocumentation/core-api/list.rst=103=list:\n--\nDocumentation/core-api/list.rst-114-\nDocumentation/core-api/list.rst:115:          grock = kzalloc_obj(*grock);\nDocumentation/core-api/list.rst-116-          if (!grock)\n--\nDocumentation/core-api/list.rst-125-\nDocumentation/core-api/list.rst:126:          dimitri = kzalloc_obj(*dimitri);\nDocumentation/core-api/list.rst-127-          if (!dimitri)\n--\nDocumentation/driver-api/mailbox.rst=45=a message and a callback function to the API and return immediately).\n--\nDocumentation/driver-api/mailbox.rst-89-\nDocumentation/driver-api/mailbox.rst:90:\t\tdc_sync = kzalloc_obj(*dc_sync);\nDocumentation/driver-api/mailbox.rst:91:\t\tdc_async = kzalloc_obj(*dc_async);\nDocumentation/driver-api/mailbox.rst-92-\n--\nDocumentation/driver-api/media/v4l2-fh.rst=26=Example:\n--\nDocumentation/driver-api/media/v4l2-fh.rst-44-\nDocumentation/driver-api/media/v4l2-fh.rst:45:\t\tmy_fh = kzalloc_obj(*my_fh);\nDocumentation/driver-api/media/v4l2-fh.rst-46-\n--\nDocumentation/process/coding-style.rst=938=The kernel provides the following general purpose memory allocators:\nDocumentation/process/coding-style.rst:939:kmalloc(), kzalloc(), kmalloc_objs(), kzalloc_objs(), vmalloc(), and\nDocumentation/process/coding-style.rst-940-vzalloc().  Please refer to the API documentation for further information\n--\nDocumentation/process/coding-style.rst=964=The preferred form for allocating a zeroed array is the following:\n--\nDocumentation/process/coding-style.rst-967-\nDocumentation/process/coding-style.rst:968:\tp = kzalloc_objs(*p, n, ...);\nDocumentation/process/coding-style.rst-969-\n--\nDocumentation/process/deprecated.rst=398=become, respectively::\n--\nDocumentation/process/deprecated.rst-400-\tptr = kmalloc_obj(*ptr [, gfp] );\nDocumentation/process/deprecated.rst:401:\tptr = kzalloc_obj(*ptr [, gfp] );\nDocumentation/process/deprecated.rst-402-\tptr = kmalloc_objs(*ptr, count [, gfp] );\nDocumentation/process/deprecated.rst:403:\tptr = kzalloc_objs(*ptr, count [, gfp] );\nDocumentation/process/deprecated.rst-404-\tptr = kmalloc_flex(*ptr, flex_member, count [, gfp] );\n--\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst=208=to details explained in the following section.\n--\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst-268-              /* allocate a chip-specific data with zero filled */\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst:269:              chip = kzalloc_obj(*chip);\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst-270-              if (chip == NULL)\n--\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst=623=After allocating a card instance via :c:func:`snd_card_new()`\n--\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst-630-  .....\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst:631:  chip = kzalloc_obj(*chip);\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst-632-\n--\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst=698=destructor and PCI entries. Example code is shown first, below::\n--\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst-749-\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst:750:              chip = kzalloc_obj(*chip);\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst-751-              if (chip == NULL) {\n--\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst=3823=chip data individually::\n--\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst-3835-          ....\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst:3836:          chip = kzalloc_obj(*chip);\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst-3837-          ....\n--\nDocumentation/translations/it_IT/process/coding-style.rst=940=Il kernel fornisce i seguenti assegnatori ad uso generico:\nDocumentation/translations/it_IT/process/coding-style.rst:941:kmalloc(), kzalloc(), kmalloc_objs(), kzalloc_objs(), vmalloc(), e vzalloc().\nDocumentation/translations/it_IT/process/coding-style.rst-942-Per maggiori informazioni, consultate la documentazione dell'API:\n--\nDocumentation/translations/it_IT/process/coding-style.rst=965=Il modo preferito per assegnare un vettore a zero è il seguente:\n--\nDocumentation/translations/it_IT/process/coding-style.rst-968-\nDocumentation/translations/it_IT/process/coding-style.rst:969:\tp = kzalloc_objs(*p, n, ...);\nDocumentation/translations/it_IT/process/coding-style.rst-970-\n--\nDocumentation/translations/it_IT/process/deprecated.rst=441=diventano, rispettivamente::\n--\nDocumentation/translations/it_IT/process/deprecated.rst-443-\tptr = kmalloc_obj(*ptr [, gfp] );\nDocumentation/translations/it_IT/process/deprecated.rst:444:\tptr = kzalloc_obj(*ptr [, gfp] );\nDocumentation/translations/it_IT/process/deprecated.rst-445-\tptr = kmalloc_objs(*ptr, count [, gfp] );\nDocumentation/translations/it_IT/process/deprecated.rst:446:\tptr = kzalloc_objs(*ptr, count [, gfp] );\nDocumentation/translations/it_IT/process/deprecated.rst-447-\tptr = kmalloc_flex(*ptr, flex_member, count [, gfp] );\n--\nDocumentation/translations/pt_BR/process/deprecated.rst=410=tornam-se, respectivamente::\n--\nDocumentation/translations/pt_BR/process/deprecated.rst-412-        ptr = kmalloc_obj(*ptr [, gfp] );\nDocumentation/translations/pt_BR/process/deprecated.rst:413:        ptr = kzalloc_obj(*ptr [, gfp] );\nDocumentation/translations/pt_BR/process/deprecated.rst-414-        ptr = kmalloc_objs(*ptr, count [, gfp] );\nDocumentation/translations/pt_BR/process/deprecated.rst:415:        ptr = kzalloc_objs(*ptr, count [, gfp] );\nDocumentation/translations/pt_BR/process/deprecated.rst-416-        ptr = kmalloc_flex(*ptr, flex_member, count [, gfp] );\n--\nDocumentation/translations/zh_CN/video4linux/v4l2-framework.txt=794=int my_open(struct file *file)\n--\nDocumentation/translations/zh_CN/video4linux/v4l2-framework.txt-801-\nDocumentation/translations/zh_CN/video4linux/v4l2-framework.txt:802:\tmy_fh = kzalloc_obj(*my_fh);\nDocumentation/translations/zh_CN/video4linux/v4l2-framework.txt-803-\n--\narch/alpha/kernel/module.c=64=module_frob_arch_sections(Elf64_Ehdr *hdr, Elf64_Shdr *sechdrs,\n--\narch/alpha/kernel/module.c-95-\tnsyms = symtab-\u003esh_size / sizeof(Elf64_Sym);\narch/alpha/kernel/module.c:96:\tchains = kzalloc_objs(struct got_entry, nsyms);\narch/alpha/kernel/module.c-97-\tif (!chains) {\n--\narch/alpha/kernel/setup.c=390=register_cpus(void)\n--\narch/alpha/kernel/setup.c-394-\tfor_each_possible_cpu(i) {\narch/alpha/kernel/setup.c:395:\t\tstruct cpu *p = kzalloc_obj(*p);\narch/alpha/kernel/setup.c-396-\t\tif (!p)\n--\narch/arc/net/bpf_jit_core.c=1120=static int jit_prepare_final_mem_alloc(struct jit_context *ctx)\n--\narch/arc/net/bpf_jit_core.c-1131-\tif (ctx-\u003eneed_extra_pass) {\narch/arc/net/bpf_jit_core.c:1132:\t\tctx-\u003ejit_data = kzalloc_obj(*ctx-\u003ejit_data);\narch/arc/net/bpf_jit_core.c-1133-\t\tif (!ctx-\u003ejit_data)\n--\narch/arm/common/locomo.c=220=locomo_init_one_child(struct locomo *lchip, struct locomo_dev_info *info)\n--\narch/arm/common/locomo.c-224-\narch/arm/common/locomo.c:225:\tdev = kzalloc_obj(struct locomo_dev);\narch/arm/common/locomo.c-226-\tif (!dev) {\n--\narch/arm/common/locomo.c=356=__locomo_probe(struct device *me, struct resource *mem, int irq)\n--\narch/arm/common/locomo.c-362-\narch/arm/common/locomo.c:363:\tlchip = kzalloc_obj(struct locomo);\narch/arm/common/locomo.c-364-\tif (!lchip)\n--\narch/arm/common/sa1111.c=733=sa1111_init_one_child(struct sa1111 *sachip, struct resource *parent,\n--\narch/arm/common/sa1111.c-739-\narch/arm/common/sa1111.c:740:\tdev = kzalloc_obj(struct sa1111_dev);\narch/arm/common/sa1111.c-741-\tif (!dev) {\n--\narch/arm/common/scoop.c=178=static int scoop_probe(struct platform_device *pdev)\n--\narch/arm/common/scoop.c-187-\narch/arm/common/scoop.c:188:\tdevptr = kzalloc_obj(struct scoop_dev);\narch/arm/common/scoop.c-189-\tif (!devptr)\n--\narch/arm/kernel/smp.c=108=static int secondary_biglittle_prepare(unsigned int cpu)\n--\narch/arm/kernel/smp.c-110-\tif (!cpu_vtable[cpu])\narch/arm/kernel/smp.c:111:\t\tcpu_vtable[cpu] = kzalloc_obj(*cpu_vtable[cpu]);\narch/arm/kernel/smp.c-112-\n--\narch/arm/kernel/vdso.c=169=static int __init vdso_init(void)\n--\narch/arm/kernel/vdso.c-181-\t/* Allocate the VDSO text pagelist */\narch/arm/kernel/vdso.c:182:\tvdso_text_pagelist = kzalloc_objs(struct page *, text_pages);\narch/arm/kernel/vdso.c-183-\tif (vdso_text_pagelist == NULL)\n--\narch/arm/mach-footbridge/dc21285.c=261=int __init dc21285_setup(int nr, struct pci_sys_data *sys)\n--\narch/arm/mach-footbridge/dc21285.c-264-\narch/arm/mach-footbridge/dc21285.c:265:\tres = kzalloc_objs(struct resource, 2);\narch/arm/mach-footbridge/dc21285.c-266-\tif (!res) {\n--\narch/arm/mach-footbridge/ebsa285.c=69=static int __init ebsa285_leds_init(void)\n--\narch/arm/mach-footbridge/ebsa285.c-86-\narch/arm/mach-footbridge/ebsa285.c:87:\t\tled = kzalloc_obj(*led);\narch/arm/mach-footbridge/ebsa285.c-88-\t\tif (!led)\n--\narch/arm/mach-footbridge/netwinder-hw.c=720=static int __init netwinder_leds_init(void)\n--\narch/arm/mach-footbridge/netwinder-hw.c-729-\narch/arm/mach-footbridge/netwinder-hw.c:730:\t\tled = kzalloc_obj(*led);\narch/arm/mach-footbridge/netwinder-hw.c-731-\t\tif (!led)\n--\narch/arm/mach-imx/mmdc.c=473=static int imx_mmdc_perf_init(struct platform_device *pdev, void __iomem *mmdc_base,\n--\narch/arm/mach-imx/mmdc.c-479-\narch/arm/mach-imx/mmdc.c:480:\tpmu_mmdc = kzalloc_obj(*pmu_mmdc);\narch/arm/mach-imx/mmdc.c-481-\tif (!pmu_mmdc) {\n--\narch/arm/mach-mvebu/board-v7.c=114=static void __init i2c_quirk(void)\n--\narch/arm/mach-mvebu/board-v7.c-129-\narch/arm/mach-mvebu/board-v7.c:130:\t\tnew_compat = kzalloc_obj(*new_compat);\narch/arm/mach-mvebu/board-v7.c-131-\n--\narch/arm/mach-mvebu/coherency.c=163=static void __init armada_375_380_coherency_init(struct device_node *np)\n--\narch/arm/mach-mvebu/coherency.c-187-\narch/arm/mach-mvebu/coherency.c:188:\t\tp = kzalloc_obj(*p);\narch/arm/mach-mvebu/coherency.c-189-\t\tp-\u003ename = kstrdup(\"arm,io-coherent\", GFP_KERNEL);\n--\narch/arm/mach-mvebu/mvebu-soc-id.c=148=static int __init mvebu_soc_device(void)\n--\narch/arm/mach-mvebu/mvebu-soc-id.c-156-\narch/arm/mach-mvebu/mvebu-soc-id.c:157:\tsoc_dev_attr = kzalloc_obj(*soc_dev_attr);\narch/arm/mach-mvebu/mvebu-soc-id.c-158-\tif (!soc_dev_attr)\n--\narch/arm/mach-mxs/mach-mxs.c=380=static void __init mxs_machine_init(void)\n--\narch/arm/mach-mxs/mach-mxs.c-389-\narch/arm/mach-mxs/mach-mxs.c:390:\tsoc_dev_attr = kzalloc_obj(*soc_dev_attr);\narch/arm/mach-mxs/mach-mxs.c-391-\tif (!soc_dev_attr)\n--\narch/arm/mach-omap1/dma.c=294=static int __init omap1_system_dma_init(void)\n--\narch/arm/mach-omap1/dma.c-321-\narch/arm/mach-omap1/dma.c:322:\td = kzalloc_obj(*d);\narch/arm/mach-omap1/dma.c-323-\tif (!d) {\n--\narch/arm/mach-omap1/mcbsp.c=292=static void omap_mcbsp_register_board_cfg(struct resource *res, int res_count,\n--\narch/arm/mach-omap1/mcbsp.c-296-\narch/arm/mach-omap1/mcbsp.c:297:\tomap_mcbsp_devices = kzalloc_objs(struct platform_device *, size);\narch/arm/mach-omap1/mcbsp.c-298-\tif (!omap_mcbsp_devices) {\n--\narch/arm/mach-omap1/timer.c=51=static int __init omap1_dm_timer_init(void)\n--\narch/arm/mach-omap1/timer.c-127-\narch/arm/mach-omap1/timer.c:128:\t\tpdata = kzalloc_obj(*pdata);\narch/arm/mach-omap1/timer.c-129-\t\tif (!pdata) {\n--\narch/arm/mach-omap2/clkt2xxx_virt_prcm_set.c=230=void omap2xxx_clkt_vps_init(void)\n--\narch/arm/mach-omap2/clkt2xxx_virt_prcm_set.c-239-\narch/arm/mach-omap2/clkt2xxx_virt_prcm_set.c:240:\thw = kzalloc_obj(*hw);\narch/arm/mach-omap2/clkt2xxx_virt_prcm_set.c-241-\tif (!hw)\n--\narch/arm/mach-omap2/id.c=786=void __init omap_soc_device_init(void)\n--\narch/arm/mach-omap2/id.c-790-\narch/arm/mach-omap2/id.c:791:\tsoc_dev_attr = kzalloc_obj(*soc_dev_attr);\narch/arm/mach-omap2/id.c-792-\tif (!soc_dev_attr)\n--\narch/arm/mach-omap2/omap_device.c=131=static int omap_device_build_from_dt(struct platform_device *pdev)\n--\narch/arm/mach-omap2/omap_device.c-158-\narch/arm/mach-omap2/omap_device.c:159:\thwmods = kzalloc_objs(struct omap_hwmod *, oh_cnt);\narch/arm/mach-omap2/omap_device.c-160-\tif (!hwmods) {\n--\narch/arm/mach-omap2/omap_hwmod.c=3389=static int omap_hwmod_allocate_module(struct device *dev, struct omap_hwmod *oh,\n--\narch/arm/mach-omap2/omap_hwmod.c-3402-\narch/arm/mach-omap2/omap_hwmod.c:3403:\tsysc = kzalloc_obj(*sysc);\narch/arm/mach-omap2/omap_hwmod.c-3404-\tif (!sysc)\n--\narch/arm/mach-omap2/omap_hwmod.c-3432-\tif (list_empty(\u0026oh-\u003eslave_ports)) {\narch/arm/mach-omap2/omap_hwmod.c:3433:\t\toi = kzalloc_obj(*oi);\narch/arm/mach-omap2/omap_hwmod.c-3434-\t\tif (!oi)\n--\narch/arm/mach-omap2/omap_hwmod.c=3521=int omap_hwmod_init_module(struct device *dev,\n--\narch/arm/mach-omap2/omap_hwmod.c-3535-\tif (!oh) {\narch/arm/mach-omap2/omap_hwmod.c:3536:\t\toh = kzalloc_obj(*oh);\narch/arm/mach-omap2/omap_hwmod.c-3537-\t\tif (!oh)\n--\narch/arm/mach-omap2/omap_hwmod.c-3546-\narch/arm/mach-omap2/omap_hwmod.c:3547:\t\toh-\u003eclass = kzalloc_obj(*oh-\u003eclass);\narch/arm/mach-omap2/omap_hwmod.c-3548-\t\tif (!oh-\u003eclass) {\n--\narch/arm/mach-omap2/pm33xx-core.c=379=static int __init amx3_idle_init(struct device_node *cpu_node, int cpu)\n--\narch/arm/mach-omap2/pm33xx-core.c-412-\narch/arm/mach-omap2/pm33xx-core.c:413:\tidle_states = kzalloc_objs(*idle_states, state_count);\narch/arm/mach-omap2/pm33xx-core.c-414-\tif (!idle_states)\n--\narch/arm/mach-omap2/sr_device.c=30=static void __init sr_set_nvalues(struct omap_volt_data *volt_data,\n--\narch/arm/mach-omap2/sr_device.c-41-\narch/arm/mach-omap2/sr_device.c:42:\tnvalue_table = kzalloc_objs(*nvalue_table, count);\narch/arm/mach-omap2/sr_device.c-43-\tif (!nvalue_table)\n--\narch/arm/mach-orion5x/pci.c=139=static int __init pcie_setup(struct pci_sys_data *sys)\n--\narch/arm/mach-orion5x/pci.c-171-\t */\narch/arm/mach-orion5x/pci.c:172:\tres = kzalloc_obj(struct resource);\narch/arm/mach-orion5x/pci.c-173-\tif (!res)\n--\narch/arm/mach-orion5x/pci.c=466=static int __init pci_setup(struct pci_sys_data *sys)\n--\narch/arm/mach-orion5x/pci.c-492-\t */\narch/arm/mach-orion5x/pci.c:493:\tres = kzalloc_obj(struct resource);\narch/arm/mach-orion5x/pci.c-494-\tif (!res)\n--\narch/arm/mach-rpc/ecard.c=689=static struct expansion_card *__init ecard_alloc_card(int type, int slot)\n--\narch/arm/mach-rpc/ecard.c-694-\narch/arm/mach-rpc/ecard.c:695:\tec = kzalloc_obj(ecard_t);\narch/arm/mach-rpc/ecard.c-696-\tif (!ec) {\n--\narch/arm/mach-sa1100/clock.c=93=int __init sa11xx_clk_init(void)\n--\narch/arm/mach-sa1100/clock.c-109-\narch/arm/mach-sa1100/clock.c:110:\thw = kzalloc_obj(*hw);\narch/arm/mach-sa1100/clock.c-111-\tif (!hw)\n--\narch/arm/mach-sa1100/clock.c-131-\narch/arm/mach-sa1100/clock.c:132:\thw = kzalloc_obj(*hw);\narch/arm/mach-sa1100/clock.c-133-\tif (!hw)\n--\narch/arm/mach-sa1100/generic.c=317=int __init sa11x0_register_fixed_regulator(int n,\n--\narch/arm/mach-sa1100/generic.c-323-\narch/arm/mach-sa1100/generic.c:324:\tcfg-\u003einit_data = id = kzalloc_obj(*cfg-\u003einit_data);\narch/arm/mach-sa1100/generic.c-325-\tif (!cfg-\u003einit_data)\n--\narch/arm/mach-sa1100/neponset.c=225=static int neponset_probe(struct platform_device *dev)\n--\narch/arm/mach-sa1100/neponset.c-278-\narch/arm/mach-sa1100/neponset.c:279:\td = kzalloc_obj(*d);\narch/arm/mach-sa1100/neponset.c-280-\tif (!d) {\n--\narch/arm/mach-shmobile/regulator-quirk-rcar-gen2.c=141=static int __init rcar_gen2_regulator_quirk(void)\n--\narch/arm/mach-shmobile/regulator-quirk-rcar-gen2.c-166-\narch/arm/mach-shmobile/regulator-quirk-rcar-gen2.c:167:\t\tquirk = kzalloc_obj(*quirk);\narch/arm/mach-shmobile/regulator-quirk-rcar-gen2.c-168-\t\tif (!quirk) {\n--\narch/arm/mach-versatile/spc.c=393=static int ve_spc_populate_opps(uint32_t cluster)\n--\narch/arm/mach-versatile/spc.c-397-\narch/arm/mach-versatile/spc.c:398:\topps = kzalloc_objs(*opps, MAX_OPPS);\narch/arm/mach-versatile/spc.c-399-\tif (!opps)\n--\narch/arm/mach-versatile/spc.c=442=int __init ve_spc_init(void __iomem *baseaddr, u32 a15_clusid, int irq)\n--\narch/arm/mach-versatile/spc.c-444-\tint ret;\narch/arm/mach-versatile/spc.c:445:\tinfo = kzalloc_obj(*info);\narch/arm/mach-versatile/spc.c-446-\tif (!info)\n--\narch/arm/mach-versatile/spc.c=523=static struct clk *ve_spc_clk_register(struct device *cpu_dev)\n--\narch/arm/mach-versatile/spc.c-527-\narch/arm/mach-versatile/spc.c:528:\tspc = kzalloc_obj(*spc);\narch/arm/mach-versatile/spc.c-529-\tif (!spc)\n--\narch/arm/mach-versatile/versatile.c=123=static void __init versatile_dt_pci_init(void)\n--\narch/arm/mach-versatile/versatile.c-144-\narch/arm/mach-versatile/versatile.c:145:\tnewprop = kzalloc_obj(*newprop);\narch/arm/mach-versatile/versatile.c-146-\tif (!newprop)\n--\narch/arm/mach-zynq/common.c=105=static void __init zynq_init_machine(void)\n--\narch/arm/mach-zynq/common.c-110-\narch/arm/mach-zynq/common.c:111:\tsoc_dev_attr = kzalloc_obj(*soc_dev_attr);\narch/arm/mach-zynq/common.c-112-\tif (!soc_dev_attr)\n--\narch/arm/mm/cache-l2x0-pmu.c=503=static __init int l2x0_pmu_init(void)\n--\narch/arm/mm/cache-l2x0-pmu.c-509-\narch/arm/mm/cache-l2x0-pmu.c:510:\tl2x0_pmu = kzalloc_obj(*l2x0_pmu);\narch/arm/mm/cache-l2x0-pmu.c-511-\tif (!l2x0_pmu) {\n--\narch/arm/mm/cache-uniphier.c=315=static int __init __uniphier_cache_init(struct device_node *np,\n--\narch/arm/mm/cache-uniphier.c-344-\narch/arm/mm/cache-uniphier.c:345:\tdata = kzalloc_obj(*data);\narch/arm/mm/cache-uniphier.c-346-\tif (!data)\n--\narch/arm/mm/dma-mapping.c=533=static void *__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,\n--\narch/arm/mm/dma-mapping.c-560-\narch/arm/mm/dma-mapping.c:561:\tbuf = kzalloc_obj(*buf,\narch/arm/mm/dma-mapping.c-562-\t\t\t  gfp \u0026 ~(__GFP_DMA | __GFP_DMA32 | __GFP_HIGHMEM));\n--\narch/arm/mm/dma-mapping.c=1487=arm_iommu_create_mapping(struct device *dev, dma_addr_t base, u64 size)\n--\narch/arm/mm/dma-mapping.c-1506-\narch/arm/mm/dma-mapping.c:1507:\tmapping = kzalloc_obj(struct dma_iommu_mapping);\narch/arm/mm/dma-mapping.c-1508-\tif (!mapping)\n--\narch/arm/xen/enlighten.c=316=int __init arch_xen_unpopulated_init(struct resource **res)\n--\narch/arm/xen/enlighten.c-343-\narch/arm/xen/enlighten.c:344:\tregs = kzalloc_objs(*regs, nr_reg);\narch/arm/xen/enlighten.c-345-\tif (!regs) {\n--\narch/arm/xen/enlighten.c-387-\narch/arm/xen/enlighten.c:388:\t\ttmp_res = kzalloc_obj(*tmp_res);\narch/arm/xen/enlighten.c-389-\t\tif (!tmp_res) {\n--\narch/arm/xen/p2m.c=150=bool __set_phys_to_machine_multi(unsigned long pfn,\n--\narch/arm/xen/p2m.c-178-\narch/arm/xen/p2m.c:179:\tp2m_entry = kzalloc_obj(*p2m_entry, GFP_NOWAIT);\narch/arm/xen/p2m.c-180-\tif (!p2m_entry)\n--\narch/arm64/kernel/vdso.c=68=static int __init __vdso_init(enum vdso_abi abi)\n--\narch/arm64/kernel/vdso.c-83-\narch/arm64/kernel/vdso.c:84:\tvdso_pagelist = kzalloc_objs(struct page *, vdso_info[abi].vdso_pages);\narch/arm64/kernel/vdso.c-85-\tif (vdso_pagelist == NULL)\n--\narch/arm64/kvm/mmu.c=480=static int share_pfn_hyp(u64 pfn)\n--\narch/arm64/kvm/mmu.c-492-\narch/arm64/kvm/mmu.c:493:\tthis = kzalloc_obj(*this);\narch/arm64/kvm/mmu.c-494-\tif (!this) {\n--\narch/arm64/kvm/mmu.c=981=int kvm_init_stage2_mmu(struct kvm *kvm, struct kvm_s2_mmu *mmu, unsigned long type)\n--\narch/arm64/kvm/mmu.c-1007-\narch/arm64/kvm/mmu.c:1008:\tpgt = kzalloc_obj(*pgt, GFP_KERNEL_ACCOUNT);\narch/arm64/kvm/mmu.c-1009-\tif (!pgt)\n--\narch/arm64/kvm/mmu.c=1180=int topup_hyp_memcache(struct kvm_hyp_memcache *mc, unsigned long min_pages)\n--\narch/arm64/kvm/mmu.c-1185-\tif (!mc-\u003emapping) {\narch/arm64/kvm/mmu.c:1186:\t\tmc-\u003emapping = kzalloc_obj(struct pkvm_mapping,\narch/arm64/kvm/mmu.c-1187-\t\t\t\t\t  GFP_KERNEL_ACCOUNT);\n--\narch/arm64/kvm/mmu.c=2513=int __init kvm_mmu_init(u32 hyp_va_bits)\n--\narch/arm64/kvm/mmu.c-2546-\narch/arm64/kvm/mmu.c:2547:\thyp_pgtable = kzalloc_obj(*hyp_pgtable);\narch/arm64/kvm/mmu.c-2548-\tif (!hyp_pgtable) {\n--\narch/arm64/kvm/nested.c=1382=int kvm_vcpu_allocate_vncr_tlb(struct kvm_vcpu *vcpu)\n--\narch/arm64/kvm/nested.c-1387-\tif (!vcpu-\u003earch.vncr_tlb) {\narch/arm64/kvm/nested.c:1388:\t\tstruct vncr_tlb *vt = kzalloc_obj(*vcpu-\u003earch.vncr_tlb,\narch/arm64/kvm/nested.c-1389-\t\t\t\t\t\t  GFP_KERNEL_ACCOUNT);\n--\narch/arm64/kvm/nested.c=1869=int kvm_init_nv_sysregs(struct kvm_vcpu *vcpu)\n--\narch/arm64/kvm/nested.c-1878-\narch/arm64/kvm/nested.c:1879:\tkvm-\u003earch.sysreg_masks = kzalloc_obj(*(kvm-\u003earch.sysreg_masks),\narch/arm64/kvm/nested.c-1880-\t\t\t\t\t     GFP_KERNEL_ACCOUNT);\n--\narch/arm64/kvm/ptdump.c=116=static struct kvm_ptdump_guest_state *kvm_ptdump_parser_create(struct kvm_s2_mmu *mmu)\n--\narch/arm64/kvm/ptdump.c-121-\narch/arm64/kvm/ptdump.c:122:\tst = kzalloc_obj(struct kvm_ptdump_guest_state, GFP_KERNEL_ACCOUNT);\narch/arm64/kvm/ptdump.c-123-\tif (!st)\n--\narch/arm64/kvm/vgic/vgic-init.c=208=static int kvm_vgic_dist_init(struct kvm *kvm, unsigned int nr_spis)\n--\narch/arm64/kvm/vgic/vgic-init.c-217-\tdist-\u003eactive_spis = (atomic_t)ATOMIC_INIT(0);\narch/arm64/kvm/vgic/vgic-init.c:218:\tdist-\u003espis = kzalloc_objs(struct vgic_irq, nr_spis, GFP_KERNEL_ACCOUNT);\narch/arm64/kvm/vgic/vgic-init.c-219-\tif (!dist-\u003espis)\n--\narch/arm64/kvm/vgic/vgic-init.c=320=static int vgic_allocate_private_irqs_locked(struct kvm_vcpu *vcpu, u32 type)\n--\narch/arm64/kvm/vgic/vgic-init.c-335-\narch/arm64/kvm/vgic/vgic-init.c:336:\tvgic_cpu-\u003eprivate_irqs = kzalloc_objs(struct vgic_irq,\narch/arm64/kvm/vgic/vgic-init.c-337-\t\t\t\t\t      num_private_irqs,\n--\narch/arm64/kvm/vgic/vgic-irqfd.c=142=int kvm_vgic_setup_default_irq_routing(struct kvm *kvm)\n--\narch/arm64/kvm/vgic/vgic-irqfd.c-148-\narch/arm64/kvm/vgic/vgic-irqfd.c:149:\tentries = kzalloc_objs(*entries, nr, GFP_KERNEL_ACCOUNT);\narch/arm64/kvm/vgic/vgic-irqfd.c-150-\tif (!entries)\n--\narch/arm64/kvm/vgic/vgic-its.c=76=static struct vgic_irq *vgic_add_lpi(struct kvm *kvm, u32 intid,\n--\narch/arm64/kvm/vgic/vgic-its.c-87-\narch/arm64/kvm/vgic/vgic-its.c:88:\tirq = kzalloc_obj(struct vgic_irq, GFP_KERNEL_ACCOUNT);\narch/arm64/kvm/vgic/vgic-its.c-89-\tif (!irq)\n--\narch/arm64/kvm/vgic/vgic-its.c=971=static int vgic_its_alloc_collection(struct vgic_its *its,\n--\narch/arm64/kvm/vgic/vgic-its.c-976-\narch/arm64/kvm/vgic/vgic-its.c:977:\tcollection = kzalloc_obj(*collection, GFP_KERNEL_ACCOUNT);\narch/arm64/kvm/vgic/vgic-its.c-978-\tif (!collection)\n--\narch/arm64/kvm/vgic/vgic-its.c=1015=static struct its_ite *vgic_its_alloc_ite(struct its_device *device,\n--\narch/arm64/kvm/vgic/vgic-its.c-1020-\narch/arm64/kvm/vgic/vgic-its.c:1021:\tite = kzalloc_obj(*ite, GFP_KERNEL_ACCOUNT);\narch/arm64/kvm/vgic/vgic-its.c-1022-\tif (!ite)\n--\narch/arm64/kvm/vgic/vgic-its.c=1142=static struct its_device *vgic_its_alloc_device(struct vgic_its *its,\n--\narch/arm64/kvm/vgic/vgic-its.c-1147-\narch/arm64/kvm/vgic/vgic-its.c:1148:\tdevice = kzalloc_obj(*device, GFP_KERNEL_ACCOUNT);\narch/arm64/kvm/vgic/vgic-its.c-1149-\tif (!device)\n--\narch/arm64/kvm/vgic/vgic-its.c=1855=static int vgic_its_create(struct kvm_device *dev, u32 type)\n--\narch/arm64/kvm/vgic/vgic-its.c-1862-\narch/arm64/kvm/vgic/vgic-its.c:1863:\tits = kzalloc_obj(struct vgic_its, GFP_KERNEL_ACCOUNT);\narch/arm64/kvm/vgic/vgic-its.c-1864-\tif (!its)\n--\narch/arm64/kvm/vgic/vgic-mmio-v3.c=886=static int vgic_v3_alloc_redist_region(struct kvm *kvm, uint32_t index,\n--\narch/arm64/kvm/vgic/vgic-mmio-v3.c-931-\narch/arm64/kvm/vgic/vgic-mmio-v3.c:932:\trdreg = kzalloc_obj(*rdreg, GFP_KERNEL_ACCOUNT);\narch/arm64/kvm/vgic/vgic-mmio-v3.c-933-\tif (!rdreg)\n--\narch/arm64/kvm/vgic/vgic-v4.c=242=int vgic_v4_init(struct kvm *kvm)\n--\narch/arm64/kvm/vgic/vgic-v4.c-258-\narch/arm64/kvm/vgic/vgic-v4.c:259:\tdist-\u003eits_vm.vpes = kzalloc_objs(*dist-\u003eits_vm.vpes, nr_vcpus,\narch/arm64/kvm/vgic/vgic-v4.c-260-\t\t\t\t\t GFP_KERNEL_ACCOUNT);\n--\narch/arm64/net/bpf_jit_comp.c=2156=struct bpf_prog *bpf_int_jit_compile(struct bpf_verifier_env *env, struct bpf_prog *prog)\n--\narch/arm64/net/bpf_jit_comp.c-2177-\tif (!jit_data) {\narch/arm64/net/bpf_jit_comp.c:2178:\t\tjit_data = kzalloc_obj(*jit_data);\narch/arm64/net/bpf_jit_comp.c-2179-\t\tif (!jit_data)\n--\narch/csky/kernel/vdso.c=17=static int __init vdso_init(void)\n--\narch/csky/kernel/vdso.c-22-\tvdso_pagelist =\n\n"
}

							input: 17564
							output: 46
							thoughts: 23

Okay, here's my take on those thoughts, tailored for an expert audience, presented in the first person:

**Analyzing the Patch's Impact**

Right, let's dive into this patch. My immediate concern is ensuring this code change doesn't introduce any subtle nasties. I need to meticulously inspect every single file this patch modifies. I'm especially on the lookout for any potential edge cases that might be exposed by these changes. Think about scenarios where unexpected inputs could lead to trouble. I need to be *sure* this patch handles those gracefully. Beyond edge cases, I’m also extremely wary of the potential for uninitialized memory usage. A careless change here could open the door to all sorts of vulnerabilities, or at the very least, unpredictable behavior. So, my goal is to verify that memory is properly initialized before any read or write operation occurs. I'm going to carefully trace the data flows and logic paths affected by this patch with the sole purpose of confirming there are no new opportunities for subtle, hard-to-debug defects.

{
  "File": "arch/s390/kvm/s390/intercept.c",
  "FirstLine": 430,
  "LineCount": 45
}

{
  "Contents": " 430:\t\tif (reg1 == reg2 || reg1 \u0026 1 || reg2 \u0026 1)\n 431:\t\t\treturn kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);\n 432:\t\n 433:\t\tif (code \u0026 0xffff) {\n 434:\t\t\tcc = 3;\n 435:\t\t\trc = 4;\n 436:\t\t\tgoto out;\n 437:\t\t}\n 438:\t\n 439:\t\tif (!kvm_s390_pv_cpu_is_protected(vcpu) \u0026\u0026 (addr \u0026 ~PAGE_MASK))\n 440:\t\t\treturn kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);\n 441:\t\n 442:\t\tsctns = kzalloc(PAGE_SIZE, GFP_KERNEL_ACCOUNT);\n 443:\t\tif (!sctns)\n 444:\t\t\treturn -ENOMEM;\n 445:\t\n 446:\t\tcc = sthyi_fill(sctns, \u0026rc);\n 447:\t\tif (cc \u003c 0) {\n 448:\t\t\tkfree(sctns);\n 449:\t\t\treturn cc;\n 450:\t\t}\n 451:\tout:\n 452:\t\tif (!cc) {\n 453:\t\t\tif (kvm_s390_pv_cpu_is_protected(vcpu)) {\n 454:\t\t\t\tmemcpy(sida_addr(vcpu-\u003earch.sie_block), sctns, PAGE_SIZE);\n 455:\t\t\t} else {\n 456:\t\t\t\tr = write_guest(vcpu, addr, reg2, sctns, PAGE_SIZE);\n 457:\t\t\t\tif (r) {\n 458:\t\t\t\t\tkfree(sctns);\n 459:\t\t\t\t\treturn kvm_s390_inject_prog_cond(vcpu, r);\n 460:\t\t\t\t}\n 461:\t\t\t}\n 462:\t\t}\n 463:\t\n 464:\t\tkfree(sctns);\n 465:\t\tvcpu-\u003erun-\u003es.regs.gprs[reg2 + 1] = rc;\n 466:\t\tkvm_s390_set_psw_cc(vcpu, cc);\n 467:\t\treturn r;\n 468:\t}\n 469:\t\n 470:\tstatic int handle_operexc(struct kvm_vcpu *vcpu)\n 471:\t{\n 472:\t\tpsw_t oldpsw, newpsw;\n 473:\t\tint rc;\n 474:\t\n"
}

							input: 18561
							output: 46
							thoughts: 24

Here's my attempt at summarizing the thought process, tailored for an expert audience and written in the first person:

**Diving into `arch/s390/kvm/s390/priv.c`**

Okay, I need to get my bearings on this specific area of the s390 KVM implementation. Time to take a look at `arch/s390/kvm/s390/priv.c`. This file almost certainly deals with privileged instruction handling and potentially the interface between the guest and the host for those types of operations, given the name. I'm expecting to see definitions for things like the hypercall interfaces, any emulated instructions that need special treatment, and possibly the structures used to represent the guest's privileged state that KVM needs to manage. I'm thinking I'll be looking for things like handlers for DIAG instruction interception, PSW manipulation within the virtual machine, and any code related to virtualization of control registers. I'll need to pay close attention to the lock usage within this file, especially if there are any race conditions that might be exploitable when dealing with sensitive operations. My first pass will likely be high level to get the structure of the file, then I'll drill down to any specific areas that look interesting to me.

{
  "File": "arch/s390/kvm/s390/priv.c",
  "FirstLine": 905,
  "LineCount": 55
}

{
  "Contents": " 905:\t\t}\n 906:\t\n 907:\t\toperand2 = kvm_s390_get_base_disp_s(vcpu, \u0026ar);\n 908:\t\n 909:\t\tif (!kvm_s390_pv_cpu_is_protected(vcpu) \u0026\u0026 (operand2 \u0026 0xfff))\n 910:\t\t\treturn kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);\n 911:\t\n 912:\t\tswitch (fc) {\n 913:\t\tcase 1: /* same handling for 1 and 2 */\n 914:\t\tcase 2:\n 915:\t\t\tmem = kzalloc(PAGE_SIZE, GFP_KERNEL_ACCOUNT);\n 916:\t\t\tif (!mem)\n 917:\t\t\t\tgoto out_no_data;\n 918:\t\t\tif (stsi(mem, fc, sel1, sel2))\n 919:\t\t\t\tgoto out_no_data;\n 920:\t\t\tbreak;\n 921:\t\tcase 3:\n 922:\t\t\tif (sel1 != 2 || sel2 != 2)\n 923:\t\t\t\tgoto out_no_data;\n 924:\t\t\tmem = kzalloc(PAGE_SIZE, GFP_KERNEL_ACCOUNT);\n 925:\t\t\tif (!mem)\n 926:\t\t\t\tgoto out_no_data;\n 927:\t\t\thandle_stsi_3_2_2(vcpu, mem);\n 928:\t\t\tbreak;\n 929:\t\tcase 15: /* fc 15 is fully handled in userspace */\n 930:\t\t\tinsert_stsi_usr_data(vcpu, operand2, ar, fc, sel1, sel2);\n 931:\t\t\ttrace_kvm_s390_handle_stsi(vcpu, fc, sel1, sel2, operand2);\n 932:\t\t\treturn -EREMOTE;\n 933:\t\t}\n 934:\t\tif (kvm_s390_pv_cpu_is_protected(vcpu)) {\n 935:\t\t\tmemcpy(sida_addr(vcpu-\u003earch.sie_block), mem, PAGE_SIZE);\n 936:\t\t\trc = 0;\n 937:\t\t} else {\n 938:\t\t\trc = write_guest(vcpu, operand2, ar, mem, PAGE_SIZE);\n 939:\t\t}\n 940:\t\tif (rc) {\n 941:\t\t\trc = kvm_s390_inject_prog_cond(vcpu, rc);\n 942:\t\t\tgoto out;\n 943:\t\t}\n 944:\t\tif (vcpu-\u003ekvm-\u003earch.user_stsi) {\n 945:\t\t\tinsert_stsi_usr_data(vcpu, operand2, ar, fc, sel1, sel2);\n 946:\t\t\trc = -EREMOTE;\n 947:\t\t}\n 948:\t\ttrace_kvm_s390_handle_stsi(vcpu, fc, sel1, sel2, operand2);\n 949:\t\tkfree(mem);\n 950:\t\tkvm_s390_set_psw_cc(vcpu, 0);\n 951:\t\tvcpu-\u003erun-\u003es.regs.gprs[0] = 0;\n 952:\t\treturn rc;\n 953:\tout_no_data:\n 954:\t\tkvm_s390_set_psw_cc(vcpu, 3);\n 955:\tout:\n 956:\t\tkfree(mem);\n 957:\t\treturn rc;\n 958:\t}\n 959:\t\n"
}

							input: 19869
							output: 50
							thoughts: 33

Here's my analysis of the situation, presented from my perspective as an expert:

**Investigating KVM/s390 Interrupt Handling**

Okay, so we're diving into the heart of the KVM/s390 interaction, specifically regarding interrupts. My first instinct, given the context, is to zero in on two key files: `arch/s390/kvm/s390/s390.c` and `interrupt.c`. `s390.c` is the likely place where core s390-specific KVM setup and functionality reside, and within that, the connection to interrupt handling will be vital. Conversely, interrupt.c is where low level interrupt functions are. Now I suspect these will provide the critical pieces of the puzzle. I expect to find the interrupt vectoring, the interrupt injection mechanisms, and the crucial interactions between the guest's view of interrupts and the host's handling of them defined in these areas. I need to understand how the hardware interrupts are mapped to guest interrupts within the KVM environment, and that will be a good starting point. Let's see what's in these files...

{
  "File": "arch/s390/kvm/s390/s390.c",
  "FirstLine": 3270,
  "LineCount": 40
}

{
  "Contents": "3270:\t\n3271:\t\tkvm-\u003earch.dbf = debug_register(debug_name, 32, 1, 7 * sizeof(long));\n3272:\t\tif (!kvm-\u003earch.dbf)\n3273:\t\t\tgoto out_err;\n3274:\t\n3275:\t\tBUILD_BUG_ON(sizeof(struct sie_page2) != 4096);\n3276:\t\tkvm-\u003earch.sie_page2 = kzalloc_obj(*kvm-\u003earch.sie_page2,\n3277:\t\t\t\t\t\t  GFP_KERNEL_ACCOUNT | GFP_DMA);\n3278:\t\tif (!kvm-\u003earch.sie_page2)\n3279:\t\t\tgoto out_err;\n3280:\t\n3281:\t\tkvm-\u003earch.sie_page2-\u003ekvm = kvm;\n3282:\t\tkvm-\u003earch.model.fac_list = kvm-\u003earch.sie_page2-\u003efac_list;\n3283:\t\n3284:\t\tfor (i = 0; i \u003c ARRAY_SIZE(kvm_s390_fac_base); i++) {\n3285:\t\t\tkvm-\u003earch.model.fac_mask[i] = stfle_fac_list[i] \u0026\n3286:\t\t\t\t\t\t      kvm_s390_fac_base[i];\n3287:\t\t\tkvm-\u003earch.model.fac_list[i] = stfle_fac_list[i] \u0026\n3288:\t\t\t\t\t\t      kvm_s390_fac_base[i];\n3289:\t\t}\n3290:\t\tfor (i = 0; i \u003c ARRAY_SIZE(kvm_s390_fac_ext); i++) {\n3291:\t\t\tkvm-\u003earch.model.fac_mask[i] |= stfle_fac_list[i] \u0026\n3292:\t\t\t\t\t\t       kvm_s390_fac_ext[i];\n3293:\t\t}\n3294:\t\tkvm-\u003earch.model.subfuncs = kvm_s390_available_subfunc;\n3295:\t\n3296:\t\t/* we are always in czam mode - even on pre z14 machines */\n3297:\t\tset_kvm_facility(kvm-\u003earch.model.fac_mask, 138);\n3298:\t\tset_kvm_facility(kvm-\u003earch.model.fac_list, 138);\n3299:\t\t/* we emulate STHYI in kvm */\n3300:\t\tset_kvm_facility(kvm-\u003earch.model.fac_mask, 74);\n3301:\t\tset_kvm_facility(kvm-\u003earch.model.fac_list, 74);\n3302:\t\tif (machine_has_tlb_guest()) {\n3303:\t\t\tset_kvm_facility(kvm-\u003earch.model.fac_mask, 147);\n3304:\t\t\tset_kvm_facility(kvm-\u003earch.model.fac_list, 147);\n3305:\t\t}\n3306:\t\n3307:\t\tif (css_general_characteristics.aiv \u0026\u0026 test_facility(65))\n3308:\t\t\tset_kvm_facility(kvm-\u003earch.model.fac_mask, 65);\n3309:\t\n"
}

							input: 21067
							output: 192
							thoughts: 268

**KMSAN Assessment: No New Risks Detected**

Okay, so this patch is a straightforward swap-out, replacing the old `get_zeroed_page` and `free_page` functions with the newer `kzalloc` (or `kzalloc_obj`) and `kfree` in the s390 KVM subsystem. The critical thing here is that the *zero-initialization* is maintained. Every single place the old code was allocating zeroed pages, the new code is also allocating zeroed memory through `kzalloc`. This is key.

There's absolutely no evidence of introducing any uninitialized memory whatsoever. No new paths are created that could potentially lead to the use of uninitialized data, and, critically, no user-space leaks are enabled. We're keeping things clean.

Given these points, my conclusion is that we absolutely do *not* need a dedicated KMSAN fuzzing session for this change. The replacement of page allocations with slab allocations, while a different mechanism, maintains the crucial zero-initialization, which is what KMSAN would be particularly concerned about. Any memory management issues from the slab conversions would be caught by KASAN anyway.

I'm ready to mark this as KMSAN-clean. Let's invoke `set-results`.

{
  "KMSANReasoning": "The patch converts page allocations via get_zeroed_page() and free_page() to slab allocations via kzalloc()/kzalloc_obj() and kfree() across s390 KVM code (intercept.c, interrupt.c, priv.c, s390.c). \n\nSince kzalloc/kzalloc_obj zero-initializes the memory identically to get_zeroed_page(), no uninitialized memory usage, conditional branches on uninitialized data, or uninitialized info-leaks to userspace/guest are introduced. Any potential slab-related memory safety issues (e.g. out-of-bounds, use-after-free, or double-free) are monitored by standard KASAN. Thus, a dedicated KMSAN fuzzing session is not required.",
  "NeedsKMSAN": false
}

{
  "KMSANReasoning": "The patch converts page allocations via get_zeroed_page() and free_page() to slab allocations via kzalloc()/kzalloc_obj() and kfree() across s390 KVM code (intercept.c, interrupt.c, priv.c, s390.c). \n\nSince kzalloc/kzalloc_obj zero-initializes the memory identically to get_zeroed_page(), no uninitialized memory usage, conditional branches on uninitialized data, or uninitialized info-leaks to userspace/guest are introduced. Any potential slab-related memory safety issues (e.g. out-of-bounds, use-after-free, or double-free) are monitored by standard KASAN. Thus, a dedicated KMSAN fuzzing session is not required.",
  "NeedsKMSAN": false
}

LLM Calls Summary:
Total Calls	Total Tokens	Avg Tokens	Total Duration (Seconds)	Avg Duration (Seconds)

Tool Calls Summary:
Total Calls	Total Duration (Seconds)	Avg Duration (Seconds)