| Seq | Timestamp | Type | Name | Duration |
|---|---|---|---|---|
| 0/0 | 2026/08/04 18:22 | flow | patch-triage |
3mArgs:null Results: {
"EnableConfigs": null,
"FocusSymbols": [
"kvm_arch_vm_ioctl",
"kvm_vm_ioctl_check_extension"
],
"Reasoning": "The patch adds a new KVM ioctl `KVM_PPC_GET_COMPAT_CAPS` for PowerPC. It introduces new functional code to handle the ioctl, copy data from/to userspace, and retrieve CPU compatibility capabilities. This is reachable from userspace via the KVM VM ioctl interface and should be fuzzed.",
"WorthFuzzing": true
} |
| 1/1 | 2026/08/04 18:22 | action | read-patch-diff |
0mArgs:null Results: {
"PatchDiff": "commit 7c80c49fda430a4f509be9d9d5969c86d362bfa2\nAuthor: syz-cluster \u003ctriage@syzkaller.com\u003e\nDate: Tue Aug 4 18:22:25 2026 +0000\n\n syz-cluster: applied patch under review\n\ndiff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst\nindex e3003a241d5b0..22fedb0aa34b4 100644\n--- a/Documentation/virt/kvm/api.rst\n+++ b/Documentation/virt/kvm/api.rst\n@@ -6566,6 +6566,85 @@ KVM_S390_KEYOP_SSKE\n Sets the storage key for the guest address ``guest_addr`` to the key\n specified in ``key``, returning the previous value in ``key``.\n \n+4.145 KVM_PPC_GET_COMPAT_CAPS\n+-----------------------------\n+:Capability: KVM_CAP_PPC_COMPAT_CAPS\n+:Architectures: powerpc\n+:Type: vm ioctl\n+:Parameters: struct kvm_ppc_compat_caps (in/out)\n+:Returns: 0 on success, negative value on failure\n+\n+Errors include:\n+\n+ ======== ============================================================\n+ EFAULT if ``struct kvm_ppc_compat_caps`` cannot be read from or\n+ written to userspace\n+ EINVAL if the ``size`` field is smaller than\n+ ``KVM_PPC_COMPAT_CAPS_SIZE_VER0``, if the ``flags`` field\n+ is non-zero, or if the backend fails to retrieve or map\n+ CPU compatibility capabilities\n+ E2BIG if ``size`` is larger than the kernel's struct size\n+ (new userspace on old kernel); the kernel writes back its\n+ own struct size into the ``size`` field so userspace can\n+ retry with the correct size\n+ ENOTTY if the backend does not implement the ``get_compat_caps``\n+ operation (e.g., on non-HV KVM implementations where the\n+ required KVM operations are not available)\n+ ======== ============================================================\n+\n+IBM POWER system server-based processors provide a compatibility mode feature\n+where an Nth generation processor can operate in modes consistent with earlier\n+generations such as (N-1) and (N-2).\n+\n+This ioctl provides userspace with information about the CPU compatibility modes\n+supported by the current host processor for booting the nested KVM guests on\n+KVM on PowerNV (nested API v1) and KVM on PowerVM (nested API v2) platforms.\n+\n+::\n+\n+ struct kvm_ppc_compat_caps {\n+\t__u64\tsize;\t\t\t/* Size of this structure */\n+\t__u64\tflags;\t\t\t/* Reserved for future use, must be 0 */\n+\t__u64\tcompat_capabilities;\t/* Capabilities supported by the host */\n+ };\n+\n+Before calling this ioctl, userspace must set the ``size`` field to\n+``sizeof(struct kvm_ppc_compat_caps)`` and zero the ``flags`` field.\n+The kernel rejects non-zero ``flags`` with ``-EINVAL`` to prevent\n+uninitialized stack values from being silently accepted, keeping the\n+field available for future use without ABI ambiguity.\n+\n+The ioctl uses ``copy_struct_from_user()`` and ``copy_struct_to_user()``\n+to support extensible versioning: if userspace passes a struct smaller\n+than the current kernel version (``size \u003e= KVM_PPC_COMPAT_CAPS_SIZE_VER0``),\n+the kernel zero-pads unknown trailing fields. If userspace passes a larger\n+struct (``size \u003e sizeof(struct kvm_ppc_compat_caps)``), the kernel writes\n+back its own struct size into the ``size`` field and returns ``-E2BIG``,\n+allowing userspace to discover the kernel's struct size and retry.\n+``KVM_PPC_COMPAT_CAPS_SIZE_VER0`` (24) is a frozen constant marking the\n+size of the initial struct version.\n+\n+The ``compat_capabilities`` bit field describes the processor compatibility\n+modes supported by the host. The following bits indicate support for specific\n+processor modes (using IBM's MSB-0 convention where bit 0 is the most\n+significant bit):\n+\n+- ``KVM_PPC_COMPAT_CAP_POWER9`` (bit 1) -- KVM guests can run in Power9 processor mode\n+- ``KVM_PPC_COMPAT_CAP_POWER10`` (bit 2) -- KVM guests can run in Power10 processor mode\n+- ``KVM_PPC_COMPAT_CAP_POWER11`` (bit 3) -- KVM guests can run in Power11 processor mode\n+\n+.. note::\n+\n+ The bit numbering above uses IBM's MSB-0 convention (bit 0 is the most\n+ significant bit). In the actual implementation, these are defined as:\n+\n+ - ``KVM_PPC_COMPAT_CAP_POWER9`` = ``(1ULL \u003c\u003c 62)``\n+ - ``KVM_PPC_COMPAT_CAP_POWER10`` = ``(1ULL \u003c\u003c 61)``\n+ - ``KVM_PPC_COMPAT_CAP_POWER11`` = ``(1ULL \u003c\u003c 60)``\n+\n+ Userspace should use the defined constants from ``\u003clinux/kvm.h\u003e`` rather\n+ than hardcoding bit positions.\n+\n .. _kvm_run:\n \n 5. The kvm_run structure\ndiff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h\nindex 0953f2daa4660..169ea6a7fbad4 100644\n--- a/arch/powerpc/include/asm/kvm_ppc.h\n+++ b/arch/powerpc/include/asm/kvm_ppc.h\n@@ -319,6 +319,7 @@ struct kvmppc_ops {\n \tbool (*hash_v3_possible)(void);\n \tint (*create_vm_debugfs)(struct kvm *kvm);\n \tint (*create_vcpu_debugfs)(struct kvm_vcpu *vcpu, struct dentry *debugfs_dentry);\n+\tint (*get_compat_caps)(struct kvm_ppc_compat_caps *host_caps);\n };\n \n extern struct kvmppc_ops *kvmppc_hv_ops;\ndiff --git a/arch/powerpc/include/uapi/asm/kvm.h b/arch/powerpc/include/uapi/asm/kvm.h\nindex 077c5437f5219..913a64b901a3d 100644\n--- a/arch/powerpc/include/uapi/asm/kvm.h\n+++ b/arch/powerpc/include/uapi/asm/kvm.h\n@@ -437,6 +437,24 @@ struct kvm_ppc_cpu_char {\n \t__u64\tbehaviour_mask;\t\t/* valid bits in behaviour */\n };\n \n+/* For KVM_PPC_GET_COMPAT_CAPS */\n+struct kvm_ppc_compat_caps {\n+\t__u64\tsize;\t\t\t/* Size of this structure */\n+\t__u64\tflags;\t\t\t/* Reserved for future use */\n+\t__u64\tcompat_capabilities;\t/* Capabilities supported by the host */\n+};\n+#define KVM_PPC_COMPAT_CAPS_SIZE_VER0\t24 /* sizeof first published struct */\n+\n+/*\n+ * Capability bits for compat_capabilities field in kvm_ppc_compat_caps.\n+ * These bits indicate which processor compatibility modes are supported.\n+ */\n+#define KVM_PPC_COMPAT_CAP_POWER9\t(1ULL \u003c\u003c 62)\n+#define KVM_PPC_COMPAT_CAP_POWER10\t(1ULL \u003c\u003c 61)\n+#define KVM_PPC_COMPAT_CAP_POWER11\t(1ULL \u003c\u003c 60)\n+#define KVM_PPC_COMPAT_BITMASK\t\t(KVM_PPC_COMPAT_CAP_POWER9 | \\\n+\t\t\t\t\t KVM_PPC_COMPAT_CAP_POWER10 | \\\n+\t\t\t\t\t KVM_PPC_COMPAT_CAP_POWER11)\n /*\n * Values for character and character_mask.\n * These are identical to the values used by H_GET_CPU_CHARACTERISTICS.\ndiff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c\nindex 61dbeea317f3b..77558f6eed864 100644\n--- a/arch/powerpc/kvm/book3s_hv.c\n+++ b/arch/powerpc/kvm/book3s_hv.c\n@@ -6510,6 +6510,61 @@ static bool kvmppc_hash_v3_possible(void)\n \treturn true;\n }\n \n+static int kvmppc_map_compat_capabilities(u32 cpu_version,\n+\t\t\t\t\t unsigned long *capabilities)\n+{\n+\tswitch (cpu_version) {\n+\tcase PVR_ARCH_31_P11:\n+\t\t*capabilities |= KVM_PPC_COMPAT_CAP_POWER11;\n+\t\tfallthrough;\n+\tcase PVR_ARCH_31:\n+\t\t*capabilities |= KVM_PPC_COMPAT_CAP_POWER10;\n+\t\tfallthrough;\n+\tcase PVR_ARCH_300:\n+\t\t*capabilities |= KVM_PPC_COMPAT_CAP_POWER9;\n+\t\tbreak;\n+\tdefault:\n+\t\treturn -EINVAL;\n+\t}\n+\n+\treturn 0;\n+}\n+\n+static int kvmppc_get_compat_caps(struct kvm_ppc_compat_caps *host_caps)\n+{\n+\tstruct device_node *np;\n+\tunsigned long capabilities = 0;\n+\tlong rc = -EINVAL;\n+\tu32 cpu_version = 0;\n+\n+\tif (kvmhv_on_pseries()) {\n+\t\tif (kvmhv_is_nestedv2()) {\n+\t\t\tWARN_ON_ONCE(!nested_capabilities);\n+\t\t\tcapabilities = nested_capabilities;\n+\t\t\trc = 0;\n+\t\t} else {\n+\t\t\tfor_each_node_by_type(np, \"cpu\") {\n+\t\t\t\tif (!of_property_read_u32(np, \"cpu-version\",\n+\t\t\t\t\t\t\t \u0026cpu_version)) {\n+\t\t\t\t\tof_node_put(np);\n+\t\t\t\t\tbreak;\n+\t\t\t\t}\n+\t\t\t}\n+\t\t\tif (!cpu_version)\n+\t\t\t\treturn -EINVAL;\n+\t\t\trc = kvmppc_map_compat_capabilities(cpu_version,\n+\t\t\t\t\t\t\t \u0026capabilities);\n+\t\t}\n+\t}\n+\n+\tif (rc \u003c 0)\n+\t\treturn rc;\n+\n+\thost_caps-\u003ecompat_capabilities = capabilities \u0026 KVM_PPC_COMPAT_BITMASK;\n+\n+\treturn rc;\n+}\n+\n static struct kvmppc_ops kvm_ops_hv = {\n \t.get_sregs = kvm_arch_vcpu_ioctl_get_sregs_hv,\n \t.set_sregs = kvm_arch_vcpu_ioctl_set_sregs_hv,\n@@ -6552,6 +6607,7 @@ static struct kvmppc_ops kvm_ops_hv = {\n \t.hash_v3_possible = kvmppc_hash_v3_possible,\n \t.create_vcpu_debugfs = kvmppc_arch_create_vcpu_debugfs_hv,\n \t.create_vm_debugfs = kvmppc_arch_create_vm_debugfs_hv,\n+\t.get_compat_caps = kvmppc_get_compat_caps,\n };\n \n static int kvm_init_subcore_bitmap(void)\ndiff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c\nindex 00302399fc37b..8d6632c64ca5f 100644\n--- a/arch/powerpc/kvm/powerpc.c\n+++ b/arch/powerpc/kvm/powerpc.c\n@@ -697,6 +697,13 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)\n \t\t\t}\n \t\t}\n \t\tbreak;\n+#if defined(CONFIG_KVM_BOOK3S_HV_POSSIBLE)\n+\tcase KVM_CAP_PPC_COMPAT_CAPS:\n+\t\tr = 0;\n+\t\tif (kvmhv_on_pseries())\n+\t\t\tr = 1;\n+\t\tbreak;\n+#endif /* CONFIG_KVM_BOOK3S_HV_POSSIBLE */\n \tdefault:\n \t\tr = 0;\n \t\tbreak;\n@@ -2463,6 +2470,70 @@ int kvm_arch_vm_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg)\n \t\tr = kvm-\u003earch.kvm_ops-\u003esvm_off(kvm);\n \t\tbreak;\n \t}\n+\tcase KVM_PPC_GET_COMPAT_CAPS: {\n+\t\tstruct kvm_ppc_compat_caps host_caps = {};\n+\t\tu64 usize;\n+\n+\t\t/*\n+\t\t * Read the size field first to drive copy_struct_from_user.\n+\t\t * size must be the first field of the struct.\n+\t\t */\n+\t\tr = -EFAULT;\n+\t\tif (get_user(usize, (__u64 __user *)argp))\n+\t\t\tgoto out;\n+\n+\t\t/*\n+\t\t * Enforce a minimum: reject buffers smaller than the initial\n+\t\t * struct version (VER0). This allows old userspace compiled\n+\t\t * against the original struct to still work on a newer kernel\n+\t\t * that has grown the struct with appended fields.\n+\t\t */\n+\t\tr = -EINVAL;\n+\t\tif (usize \u003c KVM_PPC_COMPAT_CAPS_SIZE_VER0)\n+\t\t\tgoto out;\n+\n+\t\t/*\n+\t\t * New userspace with a larger struct called an older kernel.\n+\t\t * Write back ksize in host_caps.size so userspace knows which\n+\t\t * older struct to retry with, then fail with -E2BIG.\n+\t\t */\n+\t\tif (usize \u003e sizeof(host_caps)) {\n+\t\t\thost_caps.size = sizeof(host_caps);\n+\t\t\tr = -EFAULT;\n+\t\t\tif (put_user(host_caps.size, (__u64 __user *)argp))\n+\t\t\t\tgoto out;\n+\t\t\tr = -E2BIG;\n+\t\t\tgoto out;\n+\t\t}\n+\n+\t\t/*\n+\t\t * copy_struct_from_user() handles forward/backward compat:\n+\t\t * usize == ksize: verbatim copy\n+\t\t * usize \u003c ksize: zero-pad trailing (old userspace, new kernel)\n+\t\t */\n+\t\tr = copy_struct_from_user(\u0026host_caps, sizeof(host_caps),\n+\t\t\t\t\t argp, usize);\n+\t\tif (r)\n+\t\t\tgoto out;\n+\n+\t\t/* Reserved fields must be zero */\n+\t\tr = -EINVAL;\n+\t\tif (host_caps.flags)\n+\t\t\tgoto out;\n+\n+\t\tr = -ENOTTY;\n+\t\tif (!kvm-\u003earch.kvm_ops-\u003eget_compat_caps)\n+\t\t\tgoto out;\n+\n+\t\tr = kvm-\u003earch.kvm_ops-\u003eget_compat_caps(\u0026host_caps);\n+\t\tif (r)\n+\t\t\tgoto out;\n+\n+\t\thost_caps.size = sizeof(host_caps);\n+\t\tr = copy_struct_to_user(argp, usize, \u0026host_caps,\n+\t\t\t\t\tsizeof(host_caps), NULL);\n+\t\tbreak;\n+\t}\n \tdefault: {\n \t\tstruct kvm *kvm = filp-\u003eprivate_data;\n \t\tr = kvm-\u003earch.kvm_ops-\u003earch_vm_ioctl(filp, ioctl, arg);\ndiff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h\nindex 419011097fa8e..70e36e6a0ad4b 100644\n--- a/include/uapi/linux/kvm.h\n+++ b/include/uapi/linux/kvm.h\n@@ -997,6 +997,7 @@ struct kvm_enable_cap {\n #define KVM_CAP_S390_KEYOP 247\n #define KVM_CAP_S390_VSIE_ESAMODE 248\n #define KVM_CAP_S390_HPAGE_2G 249\n+#define KVM_CAP_PPC_COMPAT_CAPS 250\n \n struct kvm_irq_routing_irqchip {\n \t__u32 irqchip;\n@@ -1341,6 +1342,8 @@ struct kvm_s390_keyop {\n /* Available with KVM_CAP_COUNTER_OFFSET */\n #define KVM_ARM_SET_COUNTER_OFFSET _IOW(KVMIO, 0xb5, struct kvm_arm_counter_offset)\n #define KVM_ARM_GET_REG_WRITABLE_MASKS _IOR(KVMIO, 0xb6, struct reg_mask_range)\n+/* Available with KVM_CAP_PPC_COMPAT_CAPS */\n+#define KVM_PPC_GET_COMPAT_CAPS\t_IO(KVMIO, 0xb8)\n \n /* ioctl for vm fd */\n #define KVM_CREATE_DEVICE\t _IOWR(KVMIO, 0xe0, struct kvm_create_device)\n"
} |
| 2/1 | 2026/08/04 18:22 | agent | patch-evaluator |
3mModel:best-expensive Args: null Results: {
"EnableConfigs": null,
"FocusSymbols": [
"kvm_arch_vm_ioctl",
"kvm_vm_ioctl_check_extension"
],
"Reasoning": "The patch adds a new KVM ioctl `KVM_PPC_GET_COMPAT_CAPS` for PowerPC. It introduces new functional code to handle the ioctl, copy data from/to userspace, and retrieve CPU compatibility capabilities. This is reachable from userspace via the KVM VM ioctl interface and should be fuzzed.",
"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 7c80c49fda430a4f509be9d9d5969c86d362bfa2
Author: syz-cluster <triage@syzkaller.com>
Date: Tue Aug 4 18:22:25 2026 +0000
syz-cluster: applied patch under review
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index e3003a241d5b0..22fedb0aa34b4 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -6566,6 +6566,85 @@ KVM_S390_KEYOP_SSKE
Sets the storage key for the guest address ``guest_addr`` to the key
specified in ``key``, returning the previous value in ``key``.
+4.145 KVM_PPC_GET_COMPAT_CAPS
+-----------------------------
+:Capability: KVM_CAP_PPC_COMPAT_CAPS
+:Architectures: powerpc
+:Type: vm ioctl
+:Parameters: struct kvm_ppc_compat_caps (in/out)
+:Returns: 0 on success, negative value on failure
+
+Errors include:
+
+ ======== ============================================================
+ EFAULT if ``struct kvm_ppc_compat_caps`` cannot be read from or
+ written to userspace
+ EINVAL if the ``size`` field is smaller than
+ ``KVM_PPC_COMPAT_CAPS_SIZE_VER0``, if the ``flags`` field
+ is non-zero, or if the backend fails to retrieve or map
+ CPU compatibility capabilities
+ E2BIG if ``size`` is larger than the kernel's struct size
+ (new userspace on old kernel); the kernel writes back its
+ own struct size into the ``size`` field so userspace can
+ retry with the correct size
+ ENOTTY if the backend does not implement the ``get_compat_caps``
+ operation (e.g., on non-HV KVM implementations where the
+ required KVM operations are not available)
+ ======== ============================================================
+
+IBM POWER system server-based processors provide a compatibility mode feature
+where an Nth generation processor can operate in modes consistent with earlier
+generations such as (N-1) and (N-2).
+
+This ioctl provides userspace with information about the CPU compatibility modes
+supported by the current host processor for booting the nested KVM guests on
+KVM on PowerNV (nested API v1) and KVM on PowerVM (nested API v2) platforms.
+
+::
+
+ struct kvm_ppc_compat_caps {
+ __u64 size; /* Size of this structure */
+ __u64 flags; /* Reserved for future use, must be 0 */
+ __u64 compat_capabilities; /* Capabilities supported by the host */
+ };
+
+Before calling this ioctl, userspace must set the ``size`` field to
+``sizeof(struct kvm_ppc_compat_caps)`` and zero the ``flags`` field.
+The kernel rejects non-zero ``flags`` with ``-EINVAL`` to prevent
+uninitialized stack values from being silently accepted, keeping the
+field available for future use without ABI ambiguity.
+
+The ioctl uses ``copy_struct_from_user()`` and ``copy_struct_to_user()``
+to support extensible versioning: if userspace passes a struct smaller
+than the current kernel version (``size >= KVM_PPC_COMPAT_CAPS_SIZE_VER0``),
+the kernel zero-pads unknown trailing fields. If userspace passes a larger
+struct (``size > sizeof(struct kvm_ppc_compat_caps)``), the kernel writes
+back its own struct size into the ``size`` field and returns ``-E2BIG``,
+allowing userspace to discover the kernel's struct size and retry.
+``KVM_PPC_COMPAT_CAPS_SIZE_VER0`` (24) is a frozen constant marking the
+size of the initial struct version.
+
+The ``compat_capabilities`` bit field describes the processor compatibility
+modes supported by the host. The following bits indicate support for specific
+processor modes (using IBM's MSB-0 convention where bit 0 is the most
+significant bit):
+
+- ``KVM_PPC_COMPAT_CAP_POWER9`` (bit 1) -- KVM guests can run in Power9 processor mode
+- ``KVM_PPC_COMPAT_CAP_POWER10`` (bit 2) -- KVM guests can run in Power10 processor mode
+- ``KVM_PPC_COMPAT_CAP_POWER11`` (bit 3) -- KVM guests can run in Power11 processor mode
+
+.. note::
+
+ The bit numbering above uses IBM's MSB-0 convention (bit 0 is the most
+ significant bit). In the actual implementation, these are defined as:
+
+ - ``KVM_PPC_COMPAT_CAP_POWER9`` = ``(1ULL << 62)``
+ - ``KVM_PPC_COMPAT_CAP_POWER10`` = ``(1ULL << 61)``
+ - ``KVM_PPC_COMPAT_CAP_POWER11`` = ``(1ULL << 60)``
+
+ Userspace should use the defined constants from ``<linux/kvm.h>`` rather
+ than hardcoding bit positions.
+
.. _kvm_run:
5. The kvm_run structure
diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index 0953f2daa4660..169ea6a7fbad4 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -319,6 +319,7 @@ struct kvmppc_ops {
bool (*hash_v3_possible)(void);
int (*create_vm_debugfs)(struct kvm *kvm);
int (*create_vcpu_debugfs)(struct kvm_vcpu *vcpu, struct dentry *debugfs_dentry);
+ int (*get_compat_caps)(struct kvm_ppc_compat_caps *host_caps);
};
extern struct kvmppc_ops *kvmppc_hv_ops;
diff --git a/arch/powerpc/include/uapi/asm/kvm.h b/arch/powerpc/include/uapi/asm/kvm.h
index 077c5437f5219..913a64b901a3d 100644
--- a/arch/powerpc/include/uapi/asm/kvm.h
+++ b/arch/powerpc/include/uapi/asm/kvm.h
@@ -437,6 +437,24 @@ struct kvm_ppc_cpu_char {
__u64 behaviour_mask; /* valid bits in behaviour */
};
+/* For KVM_PPC_GET_COMPAT_CAPS */
+struct kvm_ppc_compat_caps {
+ __u64 size; /* Size of this structure */
+ __u64 flags; /* Reserved for future use */
+ __u64 compat_capabilities; /* Capabilities supported by the host */
+};
+#define KVM_PPC_COMPAT_CAPS_SIZE_VER0 24 /* sizeof first published struct */
+
+/*
+ * Capability bits for compat_capabilities field in kvm_ppc_compat_caps.
+ * These bits indicate which processor compatibility modes are supported.
+ */
+#define KVM_PPC_COMPAT_CAP_POWER9 (1ULL << 62)
+#define KVM_PPC_COMPAT_CAP_POWER10 (1ULL << 61)
+#define KVM_PPC_COMPAT_CAP_POWER11 (1ULL << 60)
+#define KVM_PPC_COMPAT_BITMASK (KVM_PPC_COMPAT_CAP_POWER9 | \
+ KVM_PPC_COMPAT_CAP_POWER10 | \
+ KVM_PPC_COMPAT_CAP_POWER11)
/*
* Values for character and character_mask.
* These are identical to the values used by H_GET_CPU_CHARACTERISTICS.
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 61dbeea317f3b..77558f6eed864 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -6510,6 +6510,61 @@ static bool kvmppc_hash_v3_possible(void)
return true;
}
+static int kvmppc_map_compat_capabilities(u32 cpu_version,
+ unsigned long *capabilities)
+{
+ switch (cpu_version) {
+ case PVR_ARCH_31_P11:
+ *capabilities |= KVM_PPC_COMPAT_CAP_POWER11;
+ fallthrough;
+ case PVR_ARCH_31:
+ *capabilities |= KVM_PPC_COMPAT_CAP_POWER10;
+ fallthrough;
+ case PVR_ARCH_300:
+ *capabilities |= KVM_PPC_COMPAT_CAP_POWER9;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int kvmppc_get_compat_caps(struct kvm_ppc_compat_caps *host_caps)
+{
+ struct device_node *np;
+ unsigned long capabilities = 0;
+ long rc = -EINVAL;
+ u32 cpu_version = 0;
+
+ if (kvmhv_on_pseries()) {
+ if (kvmhv_is_nestedv2()) {
+ WARN_ON_ONCE(!nested_capabilities);
+ capabilities = nested_capabilities;
+ rc = 0;
+ } else {
+ for_each_node_by_type(np, "cpu") {
+ if (!of_property_read_u32(np, "cpu-version",
+ &cpu_version)) {
+ of_node_put(np);
+ break;
+ }
+ }
+ if (!cpu_version)
+ return -EINVAL;
+ rc = kvmppc_map_compat_capabilities(cpu_version,
+ &capabilities);
+ }
+ }
+
+ if (rc < 0)
+ return rc;
+
+ host_caps->compat_capabilities = capabilities & KVM_PPC_COMPAT_BITMASK;
+
+ return rc;
+}
+
static struct kvmppc_ops kvm_ops_hv = {
.get_sregs = kvm_arch_vcpu_ioctl_get_sregs_hv,
.set_sregs = kvm_arch_vcpu_ioctl_set_sregs_hv,
@@ -6552,6 +6607,7 @@ static struct kvmppc_ops kvm_ops_hv = {
.hash_v3_possible = kvmppc_hash_v3_possible,
.create_vcpu_debugfs = kvmppc_arch_create_vcpu_debugfs_hv,
.create_vm_debugfs = kvmppc_arch_create_vm_debugfs_hv,
+ .get_compat_caps = kvmppc_get_compat_caps,
};
static int kvm_init_subcore_bitmap(void)
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index 00302399fc37b..8d6632c64ca5f 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -697,6 +697,13 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
}
}
break;
+#if defined(CONFIG_KVM_BOOK3S_HV_POSSIBLE)
+ case KVM_CAP_PPC_COMPAT_CAPS:
+ r = 0;
+ if (kvmhv_on_pseries())
+ r = 1;
+ break;
+#endif /* CONFIG_KVM_BOOK3S_HV_POSSIBLE */
default:
r = 0;
break;
@@ -2463,6 +2470,70 @@ int kvm_arch_vm_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg)
r = kvm->arch.kvm_ops->svm_off(kvm);
break;
}
+ case KVM_PPC_GET_COMPAT_CAPS: {
+ struct kvm_ppc_compat_caps host_caps = {};
+ u64 usize;
+
+ /*
+ * Read the size field first to drive copy_struct_from_user.
+ * size must be the first field of the struct.
+ */
+ r = -EFAULT;
+ if (get_user(usize, (__u64 __user *)argp))
+ goto out;
+
+ /*
+ * Enforce a minimum: reject buffers smaller than the initial
+ * struct version (VER0). This allows old userspace compiled
+ * against the original struct to still work on a newer kernel
+ * that has grown the struct with appended fields.
+ */
+ r = -EINVAL;
+ if (usize < KVM_PPC_COMPAT_CAPS_SIZE_VER0)
+ goto out;
+
+ /*
+ * New userspace with a larger struct called an older kernel.
+ * Write back ksize in host_caps.size so userspace knows which
+ * older struct to retry with, then fail with -E2BIG.
+ */
+ if (usize > sizeof(host_caps)) {
+ host_caps.size = sizeof(host_caps);
+ r = -EFAULT;
+ if (put_user(host_caps.size, (__u64 __user *)argp))
+ goto out;
+ r = -E2BIG;
+ goto out;
+ }
+
+ /*
+ * copy_struct_from_user() handles forward/backward compat:
+ * usize == ksize: verbatim copy
+ * usize < ksize: zero-pad trailing (old userspace, new kernel)
+ */
+ r = copy_struct_from_user(&host_caps, sizeof(host_caps),
+ argp, usize);
+ if (r)
+ goto out;
+
+ /* Reserved fields must be zero */
+ r = -EINVAL;
+ if (host_caps.flags)
+ goto out;
+
+ r = -ENOTTY;
+ if (!kvm->arch.kvm_ops->get_compat_caps)
+ goto out;
+
+ r = kvm->arch.kvm_ops->get_compat_caps(&host_caps);
+ if (r)
+ goto out;
+
+ host_caps.size = sizeof(host_caps);
+ r = copy_struct_to_user(argp, usize, &host_caps,
+ sizeof(host_caps), NULL);
+ break;
+ }
default: {
struct kvm *kvm = filp->private_data;
r = kvm->arch.kvm_ops->arch_vm_ioctl(filp, ioctl, arg);
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 419011097fa8e..70e36e6a0ad4b 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -997,6 +997,7 @@ struct kvm_enable_cap {
#define KVM_CAP_S390_KEYOP 247
#define KVM_CAP_S390_VSIE_ESAMODE 248
#define KVM_CAP_S390_HPAGE_2G 249
+#define KVM_CAP_PPC_COMPAT_CAPS 250
struct kvm_irq_routing_irqchip {
__u32 irqchip;
@@ -1341,6 +1342,8 @@ struct kvm_s390_keyop {
/* Available with KVM_CAP_COUNTER_OFFSET */
#define KVM_ARM_SET_COUNTER_OFFSET _IOW(KVMIO, 0xb5, struct kvm_arm_counter_offset)
#define KVM_ARM_GET_REG_WRITABLE_MASKS _IOR(KVMIO, 0xb6, struct reg_mask_range)
+/* Available with KVM_CAP_PPC_COMPAT_CAPS */
+#define KVM_PPC_GET_COMPAT_CAPS _IO(KVMIO, 0xb8)
/* ioctl for vm fd */
#define KVM_CREATE_DEVICE _IOWR(KVMIO, 0xe0, struct kvm_create_device)
|
| 3/2 | 2026/08/04 18:22 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 6292 output: 36 thoughts: 364 Thoughts: **Analyzing the New KVM_PPC_GET_COMPAT_CAPS ioctl for PowerPC** Okay, so there's a new `KVM_PPC_GET_COMPAT_CAPS` ioctl that's been added to the PowerPC KVM implementation. This ioctl is accessed via the VM file descriptor, meaning we interact with it through `kvm_arch_vm_ioctl`. The implementation itself, handling the ioctl, resides in `arch/powerpc/kvm/powerpc.c`. It leverages a capability check, `KVM_CAP_PPC_COMPAT_CAPS`, and then calls `kvm->arch.kvm_ops->get_compat_caps`, which is interesting. Looking at the code, I see the meat of the functionality is in `kvmppc_get_compat_caps` within `arch/powerpc/kvm/book3s_hv.c`. Right away, this screams *new functionality*. It's targeted towards PowerPC specifically, and that alone warrants a closer look. This ioctl definitely qualifies as a good candidate for fuzzing. It's brand new, deals with user-supplied input via `copy_struct_from_user`, and importantly, returns data. User input and data return is a classic vulnerability point. Time to poke holes! Now, to make sure I can actually build this, I need to know the configuration requirements. The relevant source files are in `arch/powerpc/kvm/powerpc.c` and `arch/powerpc/kvm/book3s_hv.c`. I'm guessing the compilation of `book3s_hv.c` is controlled by a config like `CONFIG_KVM_BOOK3S_64_HV` or something similar. Time to check the `arch/powerpc/kvm/Makefile` and see. That's my next step. |
| 4/2 | 2026/08/04 18:22 | tool | grepper |
0mArgs:{
"Expression": "book3s_hv.o",
"PathPrefix": "arch/powerpc/kvm/Makefile"
}Results: {
"Output": "arch/powerpc/kvm/Makefile=62=kvm-hv-y += \\\narch/powerpc/kvm/Makefile:63:\tbook3s_hv.o \\\narch/powerpc/kvm/Makefile-64-\tbook3s_hv_interrupts.o \\\n"
} |
| 5/2 | 2026/08/04 18:22 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 7188 output: 35 thoughts: 27 Thoughts: Here's a summary of my thought process, assuming I'm an expert: **Investigating the `kvm-hv-y` Configuration** Okay, so I've identified that we're dealing with `kvm-hv-y`. My initial thought is, "Right, let's trace this back to the configuration that actually *enables* this feature." I need to understand what settings are responsible for this particular combination of technologies. I'll need to dig into the relevant configuration files, likely looking at kernel modules or hypervisor-specific setups. I need to determine the specific options or parameters that lead to `kvm-hv-y` being active. This could involve looking at boot parameters, module loading, or even more complex orchestration tools if we're dealing with a containerized environment. Ultimately, my goal is to pinpoint the *why* behind this configuration choice so I can understand its implications fully. |
| 6/2 | 2026/08/04 18:22 | tool | grepper |
0mArgs:{
"Expression": "kvm-hv-y",
"PathPrefix": "arch/powerpc/kvm/Makefile"
}Results: {
"Output": "arch/powerpc/kvm/Makefile=60=endif\narch/powerpc/kvm/Makefile-61-\narch/powerpc/kvm/Makefile:62:kvm-hv-y += \\\narch/powerpc/kvm/Makefile-63-\tbook3s_hv.o \\\n"
} |
| 7/2 | 2026/08/04 18:22 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 7530 output: 36 thoughts: 15 Thoughts: Okay, let's dive into this. Here's my take on examining `arch/powerpc/kvm/Makefile`: **Deconstructing the PowerPC KVM Makefile** Alright, I'm going to parse through the `arch/powerpc/kvm/Makefile` file. Immediately, I'm thinking about the standard structure and expected elements of a kernel Makefile within this architecture-specific context. What kind of dependencies are we talking about here? I'm anticipating finding directives for compiling KVM-specific modules and objects, likely including those dealing with hypervisor initialization, guest state management, and interaction with the POWER hardware virtualization features. I expect to see flags regarding optimization and target architecture nuances. I'll be looking for references to common KVM components and if there are any architecture specific KVM elements. I am also searching for the linking stage for the final KVM module. I will keep an eye out for how this Makefile manages object files, and the rules governing their compilation based on source files. I'm also ready to analyze if the KVM elements are built as a kernel module or linked directly with the rest of the kernel image. I am assuming that the build system is correctly configured. I will look for any clues regarding any cross-compilation specific instructions. |
| 8/2 | 2026/08/04 18:22 | tool | read-file |
0mArgs:{
"File": "arch/powerpc/kvm/Makefile",
"FirstLine": 1,
"LineCount": 100
}Results: {
"Contents": " 1:\t# SPDX-License-Identifier: GPL-2.0\n 2:\t#\n 3:\t# Makefile for Kernel-based Virtual Machine module\n 4:\t#\n 5:\t\n 6:\tccflags-y := -Ivirt/kvm -Iarch/powerpc/kvm\n 7:\t\n 8:\tinclude $(srctree)/virt/kvm/Makefile.kvm\n 9:\t\n 10:\tcommon-objs-y += powerpc.o emulate_loadstore.o\n 11:\tobj-$(CONFIG_KVM_EXIT_TIMING) += timing.o\n 12:\tobj-$(CONFIG_KVM_BOOK3S_HANDLER) += book3s_exports.o\n 13:\t\n 14:\tAFLAGS_booke_interrupts.o := -I$(objtree)/$(obj)\n 15:\t\n 16:\tkvm-e500-objs := \\\n 17:\t\t$(common-objs-y) \\\n 18:\t\temulate.o \\\n 19:\t\tbooke.o \\\n 20:\t\tbooke_emulate.o \\\n 21:\t\tbooke_interrupts.o \\\n 22:\t\te500.o \\\n 23:\t\te500_mmu.o \\\n 24:\t\te500_mmu_host.o \\\n 25:\t\te500_emulate.o\n 26:\tkvm-objs-$(CONFIG_KVM_E500V2) := $(kvm-e500-objs)\n 27:\t\n 28:\tkvm-e500mc-objs := \\\n 29:\t\t$(common-objs-y) \\\n 30:\t\temulate.o \\\n 31:\t\tbooke.o \\\n 32:\t\tbooke_emulate.o \\\n 33:\t\tbookehv_interrupts.o \\\n 34:\t\te500mc.o \\\n 35:\t\te500_mmu.o \\\n 36:\t\te500_mmu_host.o \\\n 37:\t\te500_emulate.o\n 38:\tkvm-objs-$(CONFIG_KVM_E500MC) := $(kvm-e500mc-objs)\n 39:\t\n 40:\tkvm-pr-y := \\\n 41:\t\tfpu.o \\\n 42:\t\temulate.o \\\n 43:\t\tbook3s_paired_singles.o \\\n 44:\t\tbook3s_pr.o \\\n 45:\t\tbook3s_pr_papr.o \\\n 46:\t\tbook3s_emulate.o \\\n 47:\t\tbook3s_interrupts.o \\\n 48:\t\tbook3s_mmu_hpte.o \\\n 49:\t\tbook3s_64_mmu_host.o \\\n 50:\t\tbook3s_64_mmu.o \\\n 51:\t\tbook3s_32_mmu.o\n 52:\t\n 53:\tkvm-book3s_64-builtin-objs-$(CONFIG_KVM_BOOK3S_64_HANDLER) += \\\n 54:\t\tbook3s_64_entry.o \\\n 55:\t\ttm.o\n 56:\t\n 57:\tifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE\n 58:\tkvm-book3s_64-builtin-objs-$(CONFIG_KVM_BOOK3S_64_HANDLER) += \\\n 59:\t\tbook3s_rmhandlers.o\n 60:\tendif\n 61:\t\n 62:\tkvm-hv-y += \\\n 63:\t\tbook3s_hv.o \\\n 64:\t\tbook3s_hv_interrupts.o \\\n 65:\t\tbook3s_64_mmu_hv.o \\\n 66:\t\tbook3s_64_mmu_radix.o \\\n 67:\t\tbook3s_hv_nested.o\n 68:\t\n 69:\tkvm-hv-$(CONFIG_PPC_UV) += \\\n 70:\t\tbook3s_hv_uvmem.o\n 71:\t\n 72:\tkvm-hv-$(CONFIG_PPC_TRANSACTIONAL_MEM) += \\\n 73:\t\tbook3s_hv_tm.o\n 74:\t\n 75:\tkvm-book3s_64-builtin-xics-objs-$(CONFIG_KVM_XICS) := \\\n 76:\t\tbook3s_hv_rm_xics.o\n 77:\t\n 78:\tkvm-book3s_64-builtin-tm-objs-$(CONFIG_PPC_TRANSACTIONAL_MEM) += \\\n 79:\t\tbook3s_hv_tm_builtin.o\n 80:\t\n 81:\tifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE\n 82:\tkvm-book3s_64-builtin-objs-$(CONFIG_KVM_BOOK3S_64_HANDLER) += \\\n 83:\t\tbook3s_hv_hmi.o \\\n 84:\t\tbook3s_hv_p9_entry.o \\\n 85:\t\tbook3s_hv_rmhandlers.o \\\n 86:\t\tbook3s_hv_rm_mmu.o \\\n 87:\t\tbook3s_hv_ras.o \\\n 88:\t\tbook3s_hv_builtin.o \\\n 89:\t\tbook3s_hv_p9_perf.o \\\n 90:\t\tbook3s_hv_nestedv2.o \\\n 91:\t\tguest-state-buffer.o \\\n 92:\t\t$(kvm-book3s_64-builtin-tm-objs-y) \\\n 93:\t\t$(kvm-book3s_64-builtin-xics-objs-y)\n 94:\t\n 95:\tobj-$(CONFIG_GUEST_STATE_BUFFER_TEST) += test-guest-state-buffer.o\n 96:\tendif\n 97:\t\n 98:\tkvm-book3s_64-objs-$(CONFIG_KVM_XICS) += \\\n 99:\t\tbook3s_xics.o\n 100:\t\n"
} |
| 9/2 | 2026/08/04 18:22 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 9467 output: 38 thoughts: 10 Thoughts: Okay, here's my attempt at summarizing the thought process, tailored for an expert user and presented in the first person: **Initial Assessment: Reading and Comprehension** Alright, so the task at hand is to understand the context of this "rest of the file". My initial thought is to dive right in. I need to get a holistic view before I can make a judgement. So, let’s read the rest of the file to grasp its subject and purpose. From there, I can move on to forming a comprehensive summary. |
| 10/2 | 2026/08/04 18:22 | tool | read-file |
0mArgs:{
"File": "arch/powerpc/kvm/Makefile",
"FirstLine": 101,
"LineCount": 100
}Results: {
"Contents": " 101:\tkvm-book3s_64-objs-$(CONFIG_KVM_XIVE) += book3s_xive.o book3s_xive_native.o\n 102:\tkvm-book3s_64-objs-$(CONFIG_SPAPR_TCE_IOMMU) += book3s_64_vio.o\n 103:\t\n 104:\tkvm-book3s_64-module-objs := \\\n 105:\t\t$(common-objs-y) \\\n 106:\t\tbook3s.o \\\n 107:\t\tbook3s_rtas.o \\\n 108:\t\t$(kvm-book3s_64-objs-y)\n 109:\t\n 110:\tkvm-objs-$(CONFIG_KVM_BOOK3S_64) := $(kvm-book3s_64-module-objs)\n 111:\t\n 112:\tkvm-book3s_32-objs := \\\n 113:\t\t$(common-objs-y) \\\n 114:\t\temulate.o \\\n 115:\t\tfpu.o \\\n 116:\t\tbook3s_paired_singles.o \\\n 117:\t\tbook3s.o \\\n 118:\t\tbook3s_pr.o \\\n 119:\t\tbook3s_emulate.o \\\n 120:\t\tbook3s_interrupts.o \\\n 121:\t\tbook3s_mmu_hpte.o \\\n 122:\t\tbook3s_32_mmu_host.o \\\n 123:\t\tbook3s_32_mmu.o\n 124:\tkvm-objs-$(CONFIG_KVM_BOOK3S_32) := $(kvm-book3s_32-objs)\n 125:\t\n 126:\tkvm-objs-$(CONFIG_KVM_MPIC) += mpic.o\n 127:\t\n 128:\tkvm-y += $(kvm-objs-m) $(kvm-objs-y)\n 129:\t\n 130:\tobj-$(CONFIG_KVM_E500V2) += kvm.o\n 131:\tobj-$(CONFIG_KVM_E500MC) += kvm.o\n 132:\tobj-$(CONFIG_KVM_BOOK3S_64) += kvm.o\n 133:\tobj-$(CONFIG_KVM_BOOK3S_32) += kvm.o\n 134:\t\n 135:\tobj-$(CONFIG_KVM_BOOK3S_64_PR) += kvm-pr.o\n 136:\tobj-$(CONFIG_KVM_BOOK3S_64_HV) += kvm-hv.o\n 137:\t\n 138:\tobj-y += $(kvm-book3s_64-builtin-objs-y)\n 139:\t\n 140:\t# KVM does a lot in real-mode, and 64-bit Book3S KASAN doesn't support that\n 141:\tifdef CONFIG_PPC_BOOK3S_64\n 142:\tKASAN_SANITIZE := n\n 143:\tendif\n"
} |
| 11/2 | 2026/08/04 18:22 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 10482 output: 42 thoughts: 46 Thoughts: Okay, here's my interpretation of that thought process, assuming I'm an expert in this field, presented as a first-person summary: **KVM on BOOK3S 64-bit Hypervisor: A Quick Check** Right, so `CONFIG_KVM_BOOK3S_64_HV`... that's the key configuration option I need to focus on. My immediate thought is to delve into the Kconfig files to understand its implications. Specifically, I'll head over to `arch/powerpc/kvm/Kconfig`. This is where the magic happens. I want to quickly verify if there are any critical dependencies or prerequisites associated with that config option. Are there any other flags that must be enabled or disabled for it to work correctly? Are there specific platform requirements tied to this? I need to quickly and efficiently understand the context. |
| 12/2 | 2026/08/04 18:23 | tool | grepper |
0mArgs:{
"Expression": "config KVM_BOOK3S_64_HV",
"PathPrefix": "arch/powerpc/kvm/Kconfig"
}Results: {
"Output": "arch/powerpc/kvm/Kconfig=62=config KVM_BOOK3S_64\n--\narch/powerpc/kvm/Kconfig-78-\narch/powerpc/kvm/Kconfig:79:config KVM_BOOK3S_64_HV\narch/powerpc/kvm/Kconfig-80-\ttristate \"KVM for POWER7 and later using hypervisor mode in host\"\n"
} |
| 13/2 | 2026/08/04 18:23 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 10867 output: 37 thoughts: 22 Thoughts: Here's my take on the `arch/powerpc/kvm/Kconfig` thought process, from an expert's perspective: **Diving into the PowerPC KVM Configuration** Okay, time to get my hands dirty. I'm thinking I need to refresh my memory on some PowerPC KVM configuration specifics. Line 79 of `arch/powerpc/kvm/Kconfig` is a good place to start. It's likely related to a feature I've been meaning to revisit – probably something related to a specific hardware feature or optimization. I'm expecting to find details around enabling, disabling, or configuring some aspects of the KVM infrastructure for PowerPC. It could be about specific CPU support, memory management, or maybe even some esoteric guest capabilities. I'm hoping to identify a connection between the configurations with the problem I am working with. I'll need to pay close attention to the dependencies and default values set there to fully grasp the rationale behind that particular configuration option. I'll be looking for clues on how this Kconfig option interacts with the other options. This will help me understand its implications for overall KVM performance and functionality on PowerPC. |
| 14/2 | 2026/08/04 18:23 | tool | read-file |
0mArgs:{
"File": "arch/powerpc/kvm/Kconfig",
"FirstLine": 70,
"LineCount": 30
}Results: {
"Contents": " 70:\t\thelp\n 71:\t\t Support running unmodified book3s_64 and book3s_32 guest kernels\n 72:\t\t in virtual machines on book3s_64 host processors.\n 73:\t\n 74:\t\t This module provides access to the hardware capabilities through\n 75:\t\t a character device node named /dev/kvm.\n 76:\t\n 77:\t\t If unsure, say N.\n 78:\t\n 79:\tconfig KVM_BOOK3S_64_HV\n 80:\t\ttristate \"KVM for POWER7 and later using hypervisor mode in host\"\n 81:\t\tdepends on KVM_BOOK3S_64 \u0026\u0026 PPC_POWERNV\n 82:\t\tselect KVM_BOOK3S_HV_POSSIBLE\n 83:\t\tselect KVM_BOOK3S_HV_PMU\n 84:\t\tselect CMA\n 85:\t\thelp\n 86:\t\t Support running unmodified book3s_64 guest kernels in\n 87:\t\t virtual machines on POWER7 and newer processors that have\n 88:\t\t hypervisor mode available to the host.\n 89:\t\n 90:\t\t If you say Y here, KVM will use the hardware virtualization\n 91:\t\t facilities of POWER7 (and later) processors, meaning that\n 92:\t\t guest operating systems will run at full hardware speed\n 93:\t\t using supervisor and user modes. However, this also means\n 94:\t\t that KVM is not usable under PowerVM (pHyp), is only usable\n 95:\t\t on POWER7 or later processors, and cannot emulate a\n 96:\t\t different processor from the host processor.\n 97:\t\n 98:\t\t If unsure, say N.\n 99:\t\n"
} |
| 15/2 | 2026/08/04 18:23 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 11633 output: 37 thoughts: 53 Thoughts: Okay, here's my interpretation of that thought process, tailored for an expert audience: **Dependency Tree Dive: KVM_BOOK3S_64_HV** Right, let's break this down. The configuration option `KVM_BOOK3S_64_HV` has a declared dependency chain. My immediate thought is, "Okay, where does this branch out?" I know it relies on both `KVM_BOOK3S_64` and `PPC_POWERNV`. That's the baseline. My next step is logical, I need to know the state of `KVM_BOOK3S_64`, which is now the next component of the dependency chain. I’ll need to understand if there are any specific configurations, modules, or build options related to `KVM_BOOK3S_64` that might influence the enablement of `KVM_BOOK3S_64_HV`. Time to dive deeper and see what `KVM_BOOK3S_64` brings to the table. |
| 16/2 | 2026/08/04 18:23 | tool | read-file |
0mArgs:{
"File": "arch/powerpc/kvm/Kconfig",
"FirstLine": 50,
"LineCount": 30
}Results: {
"Contents": " 50:\t\tselect KVM_BOOK3S_32_HANDLER\n 51:\t\tselect KVM_BOOK3S_PR_POSSIBLE\n 52:\t\tselect PPC_FPU\n 53:\t\thelp\n 54:\t\t Support running unmodified book3s_32 guest kernels\n 55:\t\t in virtual machines on book3s_32 host processors.\n 56:\t\n 57:\t\t This module provides access to the hardware capabilities through\n 58:\t\t a character device node named /dev/kvm.\n 59:\t\n 60:\t\t If unsure, say N.\n 61:\t\n 62:\tconfig KVM_BOOK3S_64\n 63:\t\ttristate \"KVM support for PowerPC book3s_64 processors\"\n 64:\t\tdepends on PPC_BOOK3S_64\n 65:\t\tselect KVM_BOOK3S_64_HANDLER\n 66:\t\tselect KVM\n 67:\t\tselect KVM_BOOK3S_PR_POSSIBLE if !KVM_BOOK3S_HV_POSSIBLE\n 68:\t\tselect PPC_64S_HASH_MMU\n 69:\t\tselect SPAPR_TCE_IOMMU if IOMMU_SUPPORT \u0026\u0026 (PPC_PSERIES || PPC_POWERNV)\n 70:\t\thelp\n 71:\t\t Support running unmodified book3s_64 and book3s_32 guest kernels\n 72:\t\t in virtual machines on book3s_64 host processors.\n 73:\t\n 74:\t\t This module provides access to the hardware capabilities through\n 75:\t\t a character device node named /dev/kvm.\n 76:\t\n 77:\t\t If unsure, say N.\n 78:\t\n 79:\tconfig KVM_BOOK3S_64_HV\n"
} |
| 17/2 | 2026/08/04 18:23 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 12422 output: 34 thoughts: 41 Thoughts: Okay, here's my interpretation of that thought process, assuming I'm deep in the weeds of kernel configuration: **Navigating Kernel Dependencies** Right, so `KVM_BOOK3S_64` is contingent on `PPC_BOOK3S_64`. No surprises there, but I need to confirm the specifics. Before I go further down the KVM rabbit hole, I need to understand that dependency fully. Time to dive into `PPC_BOOK3S_64` and see what that's all about. Gotta ensure the foundation is solid before building on top of it. |
| 18/2 | 2026/08/04 18:23 | tool | grepper |
0mArgs:{
"Expression": "config PPC_BOOK3S_64",
"PathPrefix": "arch/powerpc/"
}Results: {
"Output": "arch/powerpc/platforms/Kconfig.cputype=72=choice\n--\narch/powerpc/platforms/Kconfig.cputype-82-\narch/powerpc/platforms/Kconfig.cputype:83:config PPC_BOOK3S_64\narch/powerpc/platforms/Kconfig.cputype-84-\tbool \"Server processors\"\n"
} |
| 19/2 | 2026/08/04 18:23 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 12728 output: 40 thoughts: 19 Thoughts: Okay, here's my take on those thoughts, framed for an expert audience: **Diving into Kconfig.cputype** Alright, let's get down to brass tacks. I need to take a look at `arch/powerpc/platforms/Kconfig.cputype`. I'm going to start there, because it's where the CPU type configuration is likely managed within the PowerPC architecture for this platform. Kconfig files are the lifeblood of the kernel's build system and usually contain the dependencies and prompts that control which features get compiled. I'm expecting this one to be key in selecting and configuring the specific PowerPC variants we're dealing with. Knowing the specific processor family, stepping, and features is going to be vital for everything from interrupt controller setup to cache initialization. I bet this Kconfig file will specify things such as the appropriate families, like PPC64, and any special options associated with them. This is the starting point for understanding how the kernel understands and adapts to the hardware in this particular context. I need to understand all the possible options that are available here and how those settings change the other aspects of the system. |
| 20/2 | 2026/08/04 18:23 | tool | read-file |
0mArgs:{
"File": "arch/powerpc/platforms/Kconfig.cputype",
"FirstLine": 70,
"LineCount": 30
}Results: {
"Contents": " 70:\t\t Those processors have a HASH MMU.\n 71:\t\n 72:\tchoice\n 73:\t\tprompt \"Processor Type\"\n 74:\t\tdepends on PPC64\n 75:\t\thelp\n 76:\t\t There are two families of 64 bit PowerPC chips supported.\n 77:\t\t The most common ones are the desktop and server CPUs\n 78:\t\t (POWER5, 970, POWER5+, POWER6, POWER7, POWER8, POWER9 ...)\n 79:\t\n 80:\t\t The other are the \"embedded\" processors compliant with the\n 81:\t\t \"Book 3E\" variant of the architecture\n 82:\t\n 83:\tconfig PPC_BOOK3S_64\n 84:\t\tbool \"Server processors\"\n 85:\t\tselect PPC_FPU\n 86:\t\tselect PPC_HAVE_PMU_SUPPORT\n 87:\t\tselect ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE \u0026\u0026 MIGRATION\n 88:\t\tselect ARCH_ENABLE_SPLIT_PMD_PTLOCK\n 89:\t\tselect ARCH_SUPPORTS_HUGETLBFS\n 90:\t\tselect ARCH_SUPPORTS_NUMA_BALANCING\n 91:\t\tselect HAVE_MOVE_PMD\n 92:\t\tselect HAVE_MOVE_PUD\n 93:\t\tselect IRQ_WORK\n 94:\t\tselect PPC_64S_HASH_MMU if !PPC_RADIX_MMU\n 95:\t\tselect KASAN_VMALLOC if KASAN\n 96:\t\tselect ARCH_HAS_LAZY_MMU_MODE\n 97:\t\n 98:\tconfig PPC_BOOK3E_64\n 99:\t\tbool \"Embedded processors\"\n"
} |
| 21/2 | 2026/08/04 18:23 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 13483 output: 32 thoughts: 34 Thoughts: Okay, here's my interpretation of those thoughts, presented as a personal thought process, as requested: **Dependency Chain Investigation** Alright, I'm looking at this build configuration, and the first thing that jumps out is the dependency. It looks like `PPC_BOOK3S_64` is built on top of `PPC64`. That makes sense; it's a specific subset or extension, likely. Now, I need to understand the relationship better, especially if there are any potential conflicts, so let's check `PPC_POWERNV`. That's the next logical step to clarify the broader picture and see how everything interrelates. Understanding `PPC_POWERNV` will shed light on what parts of `PPC64` are used by `PPC_BOOK3S_64`. |
| 22/2 | 2026/08/04 18:23 | tool | grepper |
0mArgs:{
"Expression": "config PPC_POWERNV",
"PathPrefix": "arch/powerpc/"
}Results: {
"Output": "arch/powerpc/platforms/powernv/Kconfig-1-# SPDX-License-Identifier: GPL-2.0\narch/powerpc/platforms/powernv/Kconfig:2:config PPC_POWERNV\narch/powerpc/platforms/powernv/Kconfig-3-\tdepends on PPC64 \u0026\u0026 PPC_BOOK3S\n"
} |
| 23/2 | 2026/08/04 18:23 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 13820 output: 38 thoughts: 18 Thoughts: Here's my thought process, as if I were considering this myself: **Diving into the PowerNV Kconfig** Okay, so I need to understand something related to PowerNV, likely some configuration options or dependencies. My first move is always to go straight to the source. The `arch/powerpc/platforms/powernv/Kconfig` file is the natural place to start. It should give me the ground truth on what's available and how things are defined at the platform level for PowerNV systems. This Kconfig file will outline the various features, settings, and dependencies specific to that platform architecture. Let's see what gems are contained within... it's the key to unlocking this puzzle. |
| 24/2 | 2026/08/04 18:23 | tool | read-file |
0mArgs:{
"File": "arch/powerpc/platforms/powernv/Kconfig",
"FirstLine": 1,
"LineCount": 20
}Results: {
"Contents": " 1:\t# SPDX-License-Identifier: GPL-2.0\n 2:\tconfig PPC_POWERNV\n 3:\t\tdepends on PPC64 \u0026\u0026 PPC_BOOK3S\n 4:\t\tbool \"IBM PowerNV (Non-Virtualized) platform support\"\n 5:\t\tselect PPC_HASH_MMU_NATIVE if PPC_64S_HASH_MMU\n 6:\t\tselect PPC_XICS\n 7:\t\tselect PPC_ICP_NATIVE\n 8:\t\tselect PPC_XIVE_NATIVE\n 9:\t\tselect PPC_P7_NAP\n 10:\t\tselect FORCE_PCI\n 11:\t\tselect PCI_MSI\n 12:\t\tselect IRQ_MSI_LIB\n 13:\t\tselect EPAPR_BOOT\n 14:\t\tselect PPC_INDIRECT_PIO\n 15:\t\tselect PPC_UDBG_16550\n 16:\t\tselect CPU_FREQ\n 17:\t\tselect PPC_DOORBELL\n 18:\t\tselect MMU_NOTIFIER\n 19:\t\tselect FORCE_SMP\n 20:\t\tselect ARCH_SUPPORTS_PER_VMA_LOCK\n"
} |
| 25/2 | 2026/08/04 18:23 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 14312 output: 33 thoughts: 98 Thoughts: **Analyzing KVM/PPC Configuration and Compatibility** Okay, so I'm looking at these PowerPC configurations: `PPC64`, `PPC_BOOK3S_64`, `PPC_POWERNV`, `KVM_BOOK3S_64`, and `KVM_BOOK3S_64_HV`. It's pretty clear that these cover a range of PPC architectures, including KVM-based setups. Now, something's pinging in the back of my head... I know I've seen `kvmhv_on_pseries()` used in the context of KVM compatibility checks, specifically within `kvmppc_get_compat_caps`. That's interesting. I need to refresh my memory on the purpose of `kvmhv_on_pseries()`. I need to understand its role better in this overall context. Let's delve into what that function is actually doing. |
| 26/2 | 2026/08/04 18:23 | tool | grepper |
0mArgs:{
"Expression": "kvmhv_on_pseries",
"PathPrefix": "arch/powerpc/"
}Results: {
"Output": "arch/powerpc/include/asm/kvm_ppc.h=604=static inline bool kvm_hv_mode_active(void)\t\t{ return false; }\n--\narch/powerpc/include/asm/kvm_ppc.h-608-#ifdef CONFIG_PPC_PSERIES\narch/powerpc/include/asm/kvm_ppc.h:609:static inline bool kvmhv_on_pseries(void)\narch/powerpc/include/asm/kvm_ppc.h-610-{\n--\narch/powerpc/include/asm/kvm_ppc.h-613-#else\narch/powerpc/include/asm/kvm_ppc.h:614:static inline bool kvmhv_on_pseries(void)\narch/powerpc/include/asm/kvm_ppc.h-615-{\n--\narch/powerpc/kvm/book3s_64_mmu_radix.c=35=unsigned long __kvmhv_copy_tofrom_guest_radix(int lpid, int pid,\n--\narch/powerpc/kvm/book3s_64_mmu_radix.c-46-\t/* Can't access quadrants 1 or 2 in non-HV mode, call the HV to do it */\narch/powerpc/kvm/book3s_64_mmu_radix.c:47:\tif (kvmhv_on_pseries())\narch/powerpc/kvm/book3s_64_mmu_radix.c-48-\t\treturn plpar_hcall_norets(H_COPY_TOFROM_GUEST, lpid, pid, eaddr,\n--\narch/powerpc/kvm/book3s_64_mmu_radix.c=315=void kvmppc_radix_tlbie_page(struct kvm *kvm, unsigned long addr,\n--\narch/powerpc/kvm/book3s_64_mmu_radix.c-329-\narch/powerpc/kvm/book3s_64_mmu_radix.c:330:\tif (!kvmhv_on_pseries()) {\narch/powerpc/kvm/book3s_64_mmu_radix.c-331-\t\tradix__flush_tlb_lpid_page(lpid, addr, psize);\n--\narch/powerpc/kvm/book3s_64_mmu_radix.c=353=static void kvmppc_radix_flush_pwc(struct kvm *kvm, u64 lpid)\n--\narch/powerpc/kvm/book3s_64_mmu_radix.c-356-\narch/powerpc/kvm/book3s_64_mmu_radix.c:357:\tif (!kvmhv_on_pseries()) {\narch/powerpc/kvm/book3s_64_mmu_radix.c-358-\t\tradix__flush_pwc_lpid(lpid);\n--\narch/powerpc/kvm/book3s_hv.c=182=static bool kvmppc_ipi_thread(int cpu)\n--\narch/powerpc/kvm/book3s_hv.c-186-\t/* If we're a nested hypervisor, fall back to ordinary IPIs for now */\narch/powerpc/kvm/book3s_hv.c:187:\tif (kvmhv_on_pseries())\narch/powerpc/kvm/book3s_hv.c-188-\t\treturn false;\n--\narch/powerpc/kvm/book3s_hv.c=414=static int kvmppc_set_arch_compat(struct kvm_vcpu *vcpu, u32 arch_compat)\n--\narch/powerpc/kvm/book3s_hv.c-460-\narch/powerpc/kvm/book3s_hv.c:461:\tif (kvmhv_on_pseries() \u0026\u0026 kvmhv_is_nestedv2()) {\narch/powerpc/kvm/book3s_hv.c-462-\t\t/*\n--\narch/powerpc/kvm/book3s_hv.c=4413=static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,\n--\narch/powerpc/kvm/book3s_hv.c-4432-\narch/powerpc/kvm/book3s_hv.c:4433:\tif (kvmhv_on_pseries()) {\narch/powerpc/kvm/book3s_hv.c-4434-\t\tif (kvmhv_is_nestedv1())\n--\narch/powerpc/kvm/book3s_hv.c=4867=int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,\n--\narch/powerpc/kvm/book3s_hv.c-4946-\t\t\t */\narch/powerpc/kvm/book3s_hv.c:4947:\t\t\tif (!kvmhv_on_pseries() \u0026\u0026 (__kvmppc_get_msr_hv(vcpu) \u0026 MSR_EE))\narch/powerpc/kvm/book3s_hv.c-4948-\t\t\t\tkvmppc_inject_interrupt_hv(vcpu,\n--\narch/powerpc/kvm/book3s_hv.c=5228=static int kvm_vm_ioctl_get_smmu_info_hv(struct kvm *kvm,\n--\narch/powerpc/kvm/book3s_hv.c-5251-\t/* If running as a nested hypervisor, we don't support HPT guests */\narch/powerpc/kvm/book3s_hv.c:5252:\tif (kvmhv_on_pseries())\narch/powerpc/kvm/book3s_hv.c-5253-\t\tinfo-\u003eflags |= KVM_PPC_NO_HASH;\n--\narch/powerpc/kvm/book3s_hv.c=6145=static int kvm_arch_vm_ioctl_hv(struct file *filp,\n--\narch/powerpc/kvm/book3s_hv.c-6157-\t\t/* If we're a nested hypervisor, we currently only support radix */\narch/powerpc/kvm/book3s_hv.c:6158:\t\tif (kvmhv_on_pseries()) {\narch/powerpc/kvm/book3s_hv.c-6159-\t\t\tr = -EOPNOTSUPP;\n--\narch/powerpc/kvm/book3s_hv.c=6257=static int kvmhv_configure_mmu(struct kvm *kvm, struct kvm_ppc_mmuv3_cfg *cfg)\n--\narch/powerpc/kvm/book3s_hv.c-6284-\t/* If we're a nested hypervisor, we currently only support radix */\narch/powerpc/kvm/book3s_hv.c:6285:\tif (kvmhv_on_pseries() \u0026\u0026 !radix)\narch/powerpc/kvm/book3s_hv.c-6286-\t\treturn -EINVAL;\n--\narch/powerpc/kvm/book3s_hv.c=6533=static int kvmppc_get_compat_caps(struct kvm_ppc_compat_caps *host_caps)\n--\narch/powerpc/kvm/book3s_hv.c-6539-\narch/powerpc/kvm/book3s_hv.c:6540:\tif (kvmhv_on_pseries()) {\narch/powerpc/kvm/book3s_hv.c-6541-\t\tif (kvmhv_is_nestedv2()) {\n--\narch/powerpc/kvm/book3s_hv.c=6649=static int kvmppc_book3s_init_hv(void)\n--\narch/powerpc/kvm/book3s_hv.c-6680-#ifdef CONFIG_SMP\narch/powerpc/kvm/book3s_hv.c:6681:\tif (!xics_on_xive() \u0026\u0026 !kvmhv_on_pseries() \u0026\u0026\narch/powerpc/kvm/book3s_hv.c-6682-\t !local_paca-\u003ekvm_hstate.xics_phys) {\n--\narch/powerpc/kvm/book3s_hv.c-6722-\t */\narch/powerpc/kvm/book3s_hv.c:6723:\tif (!kvmhv_on_pseries()) {\narch/powerpc/kvm/book3s_hv.c-6724-\t\tpr_info(\"KVM-HV: Enabling IRQ bypass\\n\");\n--\narch/powerpc/kvm/book3s_hv_nested.c=439=long kvmhv_nested_init(void)\n--\narch/powerpc/kvm/book3s_hv_nested.c-444-\narch/powerpc/kvm/book3s_hv_nested.c:445:\tif (!kvmhv_on_pseries())\narch/powerpc/kvm/book3s_hv_nested.c-446-\t\treturn 0;\n--\narch/powerpc/kvm/book3s_hv_nested.c=500=void kvmhv_nested_exit(void)\n--\narch/powerpc/kvm/book3s_hv_nested.c-502-\t/*\narch/powerpc/kvm/book3s_hv_nested.c:503:\t * N.B. the kvmhv_on_pseries() test is there because it enables\narch/powerpc/kvm/book3s_hv_nested.c-504-\t * the compiler to remove the call to plpar_hcall_norets()\n--\narch/powerpc/kvm/book3s_hv_nested.c-506-\t */\narch/powerpc/kvm/book3s_hv_nested.c:507:\tif (kvmhv_on_pseries() \u0026\u0026 pseries_partition_tb) {\narch/powerpc/kvm/book3s_hv_nested.c-508-\t\tplpar_hcall_norets(H_SET_PARTITION_TABLE, 0);\n--\narch/powerpc/kvm/book3s_hv_nested.c=514=void kvmhv_flush_lpid(u64 lpid)\n--\narch/powerpc/kvm/book3s_hv_nested.c-517-\narch/powerpc/kvm/book3s_hv_nested.c:518:\tif (!kvmhv_on_pseries()) {\narch/powerpc/kvm/book3s_hv_nested.c-519-\t\tradix__flush_all_lpid(lpid);\n--\narch/powerpc/kvm/book3s_hv_nested.c=536=void kvmhv_set_ptbl_entry(u64 lpid, u64 dw0, u64 dw1)\narch/powerpc/kvm/book3s_hv_nested.c-537-{\narch/powerpc/kvm/book3s_hv_nested.c:538:\tif (!kvmhv_on_pseries()) {\narch/powerpc/kvm/book3s_hv_nested.c-539-\t\tmmu_partition_table_set_entry(lpid, dw0, dw1, true);\n--\narch/powerpc/kvm/book3s_hv_p9_perf.c=35=void switch_pmu_to_guest(struct kvm_vcpu *vcpu,\n--\narch/powerpc/kvm/book3s_hv_p9_perf.c-74-\t/* After saving PMU, before loading guest PMU, flip pmcregs_in_use */\narch/powerpc/kvm/book3s_hv_p9_perf.c:75:\tif (kvmhv_on_pseries()) {\narch/powerpc/kvm/book3s_hv_p9_perf.c-76-\t\tbarrier();\n--\narch/powerpc/kvm/book3s_hv_p9_perf.c=118=void switch_pmu_to_host(struct kvm_vcpu *vcpu,\n--\narch/powerpc/kvm/book3s_hv_p9_perf.c-186-#ifdef CONFIG_PPC_PSERIES\narch/powerpc/kvm/book3s_hv_p9_perf.c:187:\tif (kvmhv_on_pseries()) {\narch/powerpc/kvm/book3s_hv_p9_perf.c-188-\t\tbarrier();\n--\narch/powerpc/kvm/powerpc.c=502=int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)\n--\narch/powerpc/kvm/powerpc.c-690-\t\tif (hv_enabled) {\narch/powerpc/kvm/powerpc.c:691:\t\t\tif (kvmhv_on_pseries()) {\narch/powerpc/kvm/powerpc.c-692-\t\t\t\tif (pseries_reloc_on_exception())\n--\narch/powerpc/kvm/powerpc.c-702-\t\tr = 0;\narch/powerpc/kvm/powerpc.c:703:\t\tif (kvmhv_on_pseries())\narch/powerpc/kvm/powerpc.c-704-\t\t\tr = 1;\n--\narch/powerpc/kvm/test-guest-state-buffer.c=454=static void test_gs_hostwide_counters(struct kunit *test)\n--\narch/powerpc/kvm/test-guest-state-buffer.c-463-\narch/powerpc/kvm/test-guest-state-buffer.c:464:\tif (!kvmhv_on_pseries())\narch/powerpc/kvm/test-guest-state-buffer.c-465-\t\tkunit_skip(test, \"This test need a kmv-hv guest\");\n"
} |
| 27/2 | 2026/08/04 18:23 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 18269 output: 44 thoughts: 147 Thoughts: **My Analysis of `kvmhv_on_pseries()` and `kvmppc_get_compat_caps`** Okay, so I'm looking at this definition of `kvmhv_on_pseries()`. Seems straightforward enough: it's designed to tell us if we're running on a pSeries system, and the important part here is the conditional compilation. If `CONFIG_PPC_PSERIES` is defined, then the return value hinges on `cpu_has_feature(CPU_FTR_HVMODE)`. This basically means if the CPU *doesn't* have hypervisor mode, then `kvmhv_on_pseries()` returns `true`. Otherwise, when not on pSeries it returns false. Hold on... if `kvmhv_on_pseries()` *is* false, meaning we're *not* on a pSeries system, or we are on a pSeries system in hypervisor mode. Then `kvmppc_get_compat_caps` returns `-EINVAL`. This is a bit unexpected and a bit concerning, because `-EINVAL` is often a sign of incorrect or unsupported hardware or configuration, or even a programming error, something that's really worth drilling into. So, the implications here are pretty clear: We need to figure out exactly why this return is triggered and, more importantly, when. I need to understand this logic in `kvmppc_get_compat_caps` very clearly to assess the potential issues and why this non-standard return is occurring. That is the next step to review this interaction and ensure our architecture has everything it requires. |
| 28/2 | 2026/08/04 18:23 | tool | read-file |
0mArgs:{
"File": "arch/powerpc/kvm/book3s_hv.c",
"FirstLine": 6530,
"LineCount": 40
}Results: {
"Contents": "6530:\t\treturn 0;\n6531:\t}\n6532:\t\n6533:\tstatic int kvmppc_get_compat_caps(struct kvm_ppc_compat_caps *host_caps)\n6534:\t{\n6535:\t\tstruct device_node *np;\n6536:\t\tunsigned long capabilities = 0;\n6537:\t\tlong rc = -EINVAL;\n6538:\t\tu32 cpu_version = 0;\n6539:\t\n6540:\t\tif (kvmhv_on_pseries()) {\n6541:\t\t\tif (kvmhv_is_nestedv2()) {\n6542:\t\t\t\tWARN_ON_ONCE(!nested_capabilities);\n6543:\t\t\t\tcapabilities = nested_capabilities;\n6544:\t\t\t\trc = 0;\n6545:\t\t\t} else {\n6546:\t\t\t\tfor_each_node_by_type(np, \"cpu\") {\n6547:\t\t\t\t\tif (!of_property_read_u32(np, \"cpu-version\",\n6548:\t\t\t\t\t\t\t\t \u0026cpu_version)) {\n6549:\t\t\t\t\t\tof_node_put(np);\n6550:\t\t\t\t\t\tbreak;\n6551:\t\t\t\t\t}\n6552:\t\t\t\t}\n6553:\t\t\t\tif (!cpu_version)\n6554:\t\t\t\t\treturn -EINVAL;\n6555:\t\t\t\trc = kvmppc_map_compat_capabilities(cpu_version,\n6556:\t\t\t\t\t\t\t\t \u0026capabilities);\n6557:\t\t\t}\n6558:\t\t}\n6559:\t\n6560:\t\tif (rc \u003c 0)\n6561:\t\t\treturn rc;\n6562:\t\n6563:\t\thost_caps-\u003ecompat_capabilities = capabilities \u0026 KVM_PPC_COMPAT_BITMASK;\n6564:\t\n6565:\t\treturn rc;\n6566:\t}\n6567:\t\n6568:\tstatic struct kvmppc_ops kvm_ops_hv = {\n6569:\t\t.get_sregs = kvm_arch_vcpu_ioctl_get_sregs_hv,\n"
} |
| 29/2 | 2026/08/04 18:23 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 19379 output: 31 thoughts: 62 Thoughts: **Analyzing the pSeries KVM Hypervisor Check** Okay, so I'm looking at this `kvmhv_on_pseries()` function and it's pretty clear that it has to return something other than `-EINVAL` for the code to even continue down a potentially useful path. The logic seems straightforward: it looks like `kvmhv_on_pseries()` hinges on `CONFIG_PPC_PSERIES` being defined. I need to verify that `CONFIG_PPC_PSERIES` is set – that's the key to understanding if this entire section of the code is even relevant for this build. Let me double-check how that's configured. |
| 30/2 | 2026/08/04 18:23 | tool | grepper |
0mArgs:{
"Expression": "config PPC_PSERIES",
"PathPrefix": "arch/powerpc/"
}Results: {
"Output": "arch/powerpc/platforms/pseries/Kconfig-1-# SPDX-License-Identifier: GPL-2.0\narch/powerpc/platforms/pseries/Kconfig:2:config PPC_PSERIES\narch/powerpc/platforms/pseries/Kconfig-3-\tdepends on PPC64 \u0026\u0026 PPC_BOOK3S\n--\narch/powerpc/platforms/pseries/Kconfig=92=config LPARCFG\n--\narch/powerpc/platforms/pseries/Kconfig-98-\narch/powerpc/platforms/pseries/Kconfig:99:config PPC_PSERIES_DEBUG\narch/powerpc/platforms/pseries/Kconfig-100-\tdepends on PPC_PSERIES \u0026\u0026 PPC_EARLY_DEBUG\n"
} |
| 31/2 | 2026/08/04 18:23 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 19808 output: 38 thoughts: 76 Thoughts: Okay, let me think this through. **Analyzing PPC Platform Dependencies** Alright, I'm looking at this `PPC_PSERIES` definition, and immediately I see it leans on `PPC64` and `PPC_BOOK3S`. That makes sense; it's a specific PowerPC platform. Then my mind jumps to a potential conflict. Hang on, aren't `PPC_POWERNV` and `PPC_PSERIES` both considered platforms? If that's the case, can they *both* be enabled simultaneously? Seems odd. Best thing to do is delve into the configuration options. I'll need to check the relevant Kconfig file, so I'm going to jump into `arch/powerpc/platforms/pseries/Kconfig` right away and see how these platform options relate to each other. That should clear up any potential overlaps or exclusive configurations. I'm hoping there's something explicit in there about interactions between those two platforms. |
| 32/2 | 2026/08/04 18:23 | tool | read-file |
0mArgs:{
"File": "arch/powerpc/platforms/pseries/Kconfig",
"FirstLine": 1,
"LineCount": 20
}Results: {
"Contents": " 1:\t# SPDX-License-Identifier: GPL-2.0\n 2:\tconfig PPC_PSERIES\n 3:\t\tdepends on PPC64 \u0026\u0026 PPC_BOOK3S\n 4:\t\tbool \"IBM pSeries \u0026 new (POWER5-based) iSeries\"\n 5:\t\tselect HAVE_PCSPKR_PLATFORM\n 6:\t\tselect MPIC\n 7:\t\tselect OF_DYNAMIC\n 8:\t\tselect FORCE_PCI\n 9:\t\tselect PCI_MSI\n 10:\t\tselect IRQ_MSI_LIB\n 11:\t\tselect GENERIC_ALLOCATOR\n 12:\t\tselect PPC_XICS\n 13:\t\tselect PPC_XIVE_SPAPR\n 14:\t\tselect PPC_ICP_NATIVE\n 15:\t\tselect PPC_ICP_HV\n 16:\t\tselect PPC_ICS_RTAS\n 17:\t\tselect PPC_I8259\n 18:\t\tselect PPC_RTAS\n 19:\t\tselect PPC_RTAS_DAEMON\n 20:\t\tselect RTAS_ERROR_LOGGING\n"
} |
| 33/2 | 2026/08/04 18:23 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 20406 output: 37 thoughts: 86 Thoughts: **Analyzing Configuration Dependencies** Okay, so I'm confirming that these configurations, `PPC_PSERIES` and `PPC_POWERNV`, are actually boolean configs, not choice configs. That's good to know. It means we can enable *both* of them if needed, which provides flexibility in our overall system setup. Now, hold on a second... isn't `KVM_BOOK3S_64_HV` dependent on `PPC_POWERNV`? I need to double-check that dependency chain for `KVM_BOOK3S_64_HV` again. Gotta make sure everything is lining up correctly before I move forward. |
| 34/2 | 2026/08/04 18:23 | tool | read-file |
0mArgs:{
"File": "arch/powerpc/kvm/Kconfig",
"FirstLine": 75,
"LineCount": 20
}Results: {
"Contents": " 75:\t\t a character device node named /dev/kvm.\n 76:\t\n 77:\t\t If unsure, say N.\n 78:\t\n 79:\tconfig KVM_BOOK3S_64_HV\n 80:\t\ttristate \"KVM for POWER7 and later using hypervisor mode in host\"\n 81:\t\tdepends on KVM_BOOK3S_64 \u0026\u0026 PPC_POWERNV\n 82:\t\tselect KVM_BOOK3S_HV_POSSIBLE\n 83:\t\tselect KVM_BOOK3S_HV_PMU\n 84:\t\tselect CMA\n 85:\t\thelp\n 86:\t\t Support running unmodified book3s_64 guest kernels in\n 87:\t\t virtual machines on POWER7 and newer processors that have\n 88:\t\t hypervisor mode available to the host.\n 89:\t\n 90:\t\t If you say Y here, KVM will use the hardware virtualization\n 91:\t\t facilities of POWER7 (and later) processors, meaning that\n 92:\t\t guest operating systems will run at full hardware speed\n 93:\t\t using supervisor and user modes. However, this also means\n 94:\t\t that KVM is not usable under PowerVM (pHyp), is only usable\n"
} |
| 35/2 | 2026/08/04 18:23 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 21003 output: 33 thoughts: 290 Thoughts: **KVM PowerNV and pSeries Configuration Conundrum** Okay, so I'm digging into this KVM configuration, and I've hit a snag. It looks like `KVM_BOOK3S_64_HV` has a dependency on `PPC_POWERNV`. Fine, makes sense, we're talking about a PowerNV setup. But then, the `kvmhv_on_pseries()` function is required and that function needs `PPC_PSERIES`. Hmmm, I need *both* `PPC_POWERNV` and `PPC_PSERIES` to be enabled, but are they compatible? Let me quickly dissect that `kvmhv_on_pseries()` function to make sure I'm not missing something. Right, if `PPC_PSERIES` isn't enabled, the function just returns `false`. And if it's `false`, then `kvmppc_get_compat_caps` is returning `-EINVAL`. Okay, so, if `PPC_PSERIES` is *not* set, the check bails. Clearly, `PPC_PSERIES` is a hard requirement. So, the key question is, can they coexist? Let me check the config options. Ah, good news! They are both `bool` options under `PPC64 && PPC_BOOK3S`. That simplifies things. They aren't mutually exclusive. That's a huge relief. So as long as `PPC_BOOK3S` is set, I can enable both `PPC_POWERNV` and `PPC_PSERIES` and I should be good to go. Now, let's just make sure that KVM itself is configured correctly... |
| 36/2 | 2026/08/04 18:24 | tool | grepper |
0mArgs:{
"Expression": "config KVM",
"PathPrefix": "arch/powerpc/kvm/Kconfig"
}Results: {
"Output": "arch/powerpc/kvm/Kconfig=18=if VIRTUALIZATION\narch/powerpc/kvm/Kconfig-19-\narch/powerpc/kvm/Kconfig:20:config KVM\narch/powerpc/kvm/Kconfig-21-\tbool\n--\narch/powerpc/kvm/Kconfig-25-\narch/powerpc/kvm/Kconfig:26:config KVM_BOOK3S_HANDLER\narch/powerpc/kvm/Kconfig-27-\tbool\narch/powerpc/kvm/Kconfig-28-\narch/powerpc/kvm/Kconfig:29:config KVM_BOOK3S_32_HANDLER\narch/powerpc/kvm/Kconfig-30-\tbool\n--\narch/powerpc/kvm/Kconfig-33-\narch/powerpc/kvm/Kconfig:34:config KVM_BOOK3S_64_HANDLER\narch/powerpc/kvm/Kconfig-35-\tbool\n--\narch/powerpc/kvm/Kconfig-37-\narch/powerpc/kvm/Kconfig:38:config KVM_BOOK3S_PR_POSSIBLE\narch/powerpc/kvm/Kconfig-39-\tbool\n--\narch/powerpc/kvm/Kconfig-41-\narch/powerpc/kvm/Kconfig:42:config KVM_BOOK3S_HV_POSSIBLE\narch/powerpc/kvm/Kconfig-43-\tbool\narch/powerpc/kvm/Kconfig-44-\narch/powerpc/kvm/Kconfig:45:config KVM_BOOK3S_32\narch/powerpc/kvm/Kconfig-46-\ttristate \"KVM support for PowerPC book3s_32 processors\"\n--\narch/powerpc/kvm/Kconfig-61-\narch/powerpc/kvm/Kconfig:62:config KVM_BOOK3S_64\narch/powerpc/kvm/Kconfig-63-\ttristate \"KVM support for PowerPC book3s_64 processors\"\n--\narch/powerpc/kvm/Kconfig-78-\narch/powerpc/kvm/Kconfig:79:config KVM_BOOK3S_64_HV\narch/powerpc/kvm/Kconfig-80-\ttristate \"KVM for POWER7 and later using hypervisor mode in host\"\n--\narch/powerpc/kvm/Kconfig-99-\narch/powerpc/kvm/Kconfig:100:config KVM_BOOK3S_64_PR\narch/powerpc/kvm/Kconfig-101-\ttristate \"KVM support without using hypervisor mode in host\"\n--\narch/powerpc/kvm/Kconfig-125-\narch/powerpc/kvm/Kconfig:126:config KVM_BOOK3S_HV_EXIT_TIMING\narch/powerpc/kvm/Kconfig-127-\tbool\narch/powerpc/kvm/Kconfig-128-\narch/powerpc/kvm/Kconfig:129:config KVM_BOOK3S_HV_P9_TIMING\narch/powerpc/kvm/Kconfig-130-\tbool \"Detailed timing for the P9 entry point\"\n--\narch/powerpc/kvm/Kconfig-141-\narch/powerpc/kvm/Kconfig:142:config KVM_BOOK3S_HV_P8_TIMING\narch/powerpc/kvm/Kconfig-143-\tbool \"Detailed timing for hypervisor real-mode code (for POWER8)\"\n--\narch/powerpc/kvm/Kconfig-156-\narch/powerpc/kvm/Kconfig:157:config KVM_BOOK3S_HV_NESTED_PMU_WORKAROUND\narch/powerpc/kvm/Kconfig-158-\tbool \"Nested L0 host workaround for L1 KVM host PMU handling bug\" if EXPERT\n--\narch/powerpc/kvm/Kconfig-171-\narch/powerpc/kvm/Kconfig:172:config KVM_BOOK3S_HV_PMU\narch/powerpc/kvm/Kconfig-173-\ttristate \"Hypervisor Perf events for KVM Book3s-HV\"\n--\narch/powerpc/kvm/Kconfig-183-\narch/powerpc/kvm/Kconfig:184:config KVM_BOOKE_HV\narch/powerpc/kvm/Kconfig-185-\tbool\narch/powerpc/kvm/Kconfig-186-\narch/powerpc/kvm/Kconfig:187:config KVM_EXIT_TIMING\narch/powerpc/kvm/Kconfig-188-\tbool \"Detailed exit timing\"\n--\narch/powerpc/kvm/Kconfig-197-\narch/powerpc/kvm/Kconfig:198:config KVM_E500V2\narch/powerpc/kvm/Kconfig-199-\tbool \"KVM support for PowerPC E500v2 processors\"\n--\narch/powerpc/kvm/Kconfig-212-\narch/powerpc/kvm/Kconfig:213:config KVM_E500MC\narch/powerpc/kvm/Kconfig-214-\tbool \"KVM support for PowerPC E500MC/E5500/E6500 processors\"\n--\narch/powerpc/kvm/Kconfig-228-\narch/powerpc/kvm/Kconfig:229:config KVM_MPIC\narch/powerpc/kvm/Kconfig-230-\tbool \"KVM in-kernel MPIC emulation\"\n--\narch/powerpc/kvm/Kconfig-240-\narch/powerpc/kvm/Kconfig:241:config KVM_XICS\narch/powerpc/kvm/Kconfig-242-\tbool \"KVM in-kernel XICS emulation\"\n--\narch/powerpc/kvm/Kconfig-250-\narch/powerpc/kvm/Kconfig:251:config KVM_XIVE\narch/powerpc/kvm/Kconfig-252-\tbool\n"
} |
| 37/2 | 2026/08/04 18:24 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 23273 output: 34 thoughts: 642 Thoughts: **Analyzing KVM Book3S 64 HV Configuration and Compatibility** Alright, let's break this down. My primary focus is `KVM_BOOK3S_64_HV`, which I know is the main configuration. First, I need to understand its dependencies. It looks like `KVM_BOOK3S_64_HV` requires `PPC_POWERNV`. Okay, that makes sense. Let's see how deep this rabbit hole goes. `KVM_BOOK3S_64` depends on `PPC_BOOK3S_64`, which in turn, depends on `PPC64`. And, just to be thorough, `PPC_PSERIES` also depends on `PPC64` and `PPC_BOOK3S`. So, from these dependencies, the base configuration appears to include `PPC64`, `PPC_BOOK3S_64`, `PPC_POWERNV`, `PPC_PSERIES`, and the KVM components. However, I realize `KVM` is just a boolean selected by `KVM_BOOK3S_64`, so the critical components here are `KVM_BOOK3S_64`, `KVM_BOOK3S_64_HV`, `PPC_POWERNV`, and `PPC_PSERIES`. Now, let's revisit `kvmppc_get_compat_caps`. I need to ensure the system is correctly identifying and handling compatibility capabilities, especially related to nested virtualization. I am curious about the path in this function: `kvmhv_is_nestedv2()`. I want to verify if this is even reachable. Given my understanding of the system, this condition seems relevant. |
| 38/2 | 2026/08/04 18:24 | tool | grepper |
0mArgs:{
"Expression": "kvmhv_is_nestedv2",
"PathPrefix": "arch/powerpc/"
}Results: {
"Output": "arch/powerpc/include/asm/kvm_book3s.h=320=void kvmppc_giveup_fac(struct kvm_vcpu *vcpu, ulong fac);\n--\narch/powerpc/include/asm/kvm_book3s.h-324-\narch/powerpc/include/asm/kvm_book3s.h:325:extern struct static_key_false __kvmhv_is_nestedv2;\narch/powerpc/include/asm/kvm_book3s.h-326-\narch/powerpc/include/asm/kvm_book3s.h:327:static inline bool kvmhv_is_nestedv2(void)\narch/powerpc/include/asm/kvm_book3s.h-328-{\narch/powerpc/include/asm/kvm_book3s.h:329:\treturn static_branch_unlikely(\u0026__kvmhv_is_nestedv2);\narch/powerpc/include/asm/kvm_book3s.h-330-}\n--\narch/powerpc/include/asm/kvm_book3s.h=332=static inline bool kvmhv_is_nestedv1(void)\narch/powerpc/include/asm/kvm_book3s.h-333-{\narch/powerpc/include/asm/kvm_book3s.h:334:\treturn !static_branch_likely(\u0026__kvmhv_is_nestedv2);\narch/powerpc/include/asm/kvm_book3s.h-335-}\n--\narch/powerpc/include/asm/kvm_book3s.h-338-\narch/powerpc/include/asm/kvm_book3s.h:339:static inline bool kvmhv_is_nestedv2(void)\narch/powerpc/include/asm/kvm_book3s.h-340-{\n--\narch/powerpc/include/asm/kvm_book3s.h=356=static inline int kvmhv_nestedv2_reload_ptregs(struct kvm_vcpu *vcpu,\n--\narch/powerpc/include/asm/kvm_book3s.h-358-{\narch/powerpc/include/asm/kvm_book3s.h:359:\tif (kvmhv_is_nestedv2())\narch/powerpc/include/asm/kvm_book3s.h-360-\t\treturn __kvmhv_nestedv2_reload_ptregs(vcpu, regs);\n--\narch/powerpc/include/asm/kvm_book3s.h=363=static inline int kvmhv_nestedv2_mark_dirty_ptregs(struct kvm_vcpu *vcpu,\n--\narch/powerpc/include/asm/kvm_book3s.h-365-{\narch/powerpc/include/asm/kvm_book3s.h:366:\tif (kvmhv_is_nestedv2())\narch/powerpc/include/asm/kvm_book3s.h-367-\t\treturn __kvmhv_nestedv2_mark_dirty_ptregs(vcpu, regs);\n--\narch/powerpc/include/asm/kvm_book3s.h=371=static inline int kvmhv_nestedv2_mark_dirty(struct kvm_vcpu *vcpu, u16 iden)\narch/powerpc/include/asm/kvm_book3s.h-372-{\narch/powerpc/include/asm/kvm_book3s.h:373:\tif (kvmhv_is_nestedv2())\narch/powerpc/include/asm/kvm_book3s.h-374-\t\treturn __kvmhv_nestedv2_mark_dirty(vcpu, iden);\n--\narch/powerpc/include/asm/kvm_book3s.h=378=static inline int kvmhv_nestedv2_cached_reload(struct kvm_vcpu *vcpu, u16 iden)\narch/powerpc/include/asm/kvm_book3s.h-379-{\narch/powerpc/include/asm/kvm_book3s.h:380:\tif (kvmhv_is_nestedv2())\narch/powerpc/include/asm/kvm_book3s.h-381-\t\treturn __kvmhv_nestedv2_cached_reload(vcpu, iden);\n--\narch/powerpc/include/asm/kvm_ppc.h=614=static inline bool kvmhv_on_pseries(void)\n--\narch/powerpc/include/asm/kvm_ppc.h-622-\narch/powerpc/include/asm/kvm_ppc.h:623:static inline bool kvmhv_is_nestedv2(void)\narch/powerpc/include/asm/kvm_ppc.h-624-{\n--\narch/powerpc/kvm/book3s.c=296=static int kvmppc_book3s_irqprio_deliver(struct kvm_vcpu *vcpu,\n--\narch/powerpc/kvm/book3s.c-304-\tcase BOOK3S_IRQPRIO_DECREMENTER:\narch/powerpc/kvm/book3s.c:305:\t\tdeliver = !kvmhv_is_nestedv2() \u0026\u0026 (kvmppc_get_msr(vcpu) \u0026 MSR_EE) \u0026\u0026 !crit;\narch/powerpc/kvm/book3s.c-306-\t\tvec = BOOK3S_INTERRUPT_DECREMENTER;\n--\narch/powerpc/kvm/book3s.c-308-\tcase BOOK3S_IRQPRIO_EXTERNAL:\narch/powerpc/kvm/book3s.c:309:\t\tdeliver = !kvmhv_is_nestedv2() \u0026\u0026 (kvmppc_get_msr(vcpu) \u0026 MSR_EE) \u0026\u0026 !crit;\narch/powerpc/kvm/book3s.c-310-\t\tvec = BOOK3S_INTERRUPT_EXTERNAL;\n--\narch/powerpc/kvm/book3s_64_mmu_radix.c=35=unsigned long __kvmhv_copy_tofrom_guest_radix(int lpid, int pid,\n--\narch/powerpc/kvm/book3s_64_mmu_radix.c-42-\narch/powerpc/kvm/book3s_64_mmu_radix.c:43:\tif (kvmhv_is_nestedv2())\narch/powerpc/kvm/book3s_64_mmu_radix.c-44-\t\treturn H_UNSUPPORTED;\n--\narch/powerpc/kvm/book3s_hv.c=414=static int kvmppc_set_arch_compat(struct kvm_vcpu *vcpu, u32 arch_compat)\n--\narch/powerpc/kvm/book3s_hv.c-460-\narch/powerpc/kvm/book3s_hv.c:461:\tif (kvmhv_on_pseries() \u0026\u0026 kvmhv_is_nestedv2()) {\narch/powerpc/kvm/book3s_hv.c-462-\t\t/*\n--\narch/powerpc/kvm/book3s_hv.c=728=static void kvmppc_update_vpas(struct kvm_vcpu *vcpu)\n--\narch/powerpc/kvm/book3s_hv.c-741-\t\tif (old_vpa.pinned_addr) {\narch/powerpc/kvm/book3s_hv.c:742:\t\t\tif (kvmhv_is_nestedv2())\narch/powerpc/kvm/book3s_hv.c-743-\t\t\t\tkvmhv_nestedv2_set_vpa(vcpu, ~0ull);\n--\narch/powerpc/kvm/book3s_hv.c-748-\t\t\tinit_vpa(vcpu, vcpu-\u003earch.vpa.pinned_addr);\narch/powerpc/kvm/book3s_hv.c:749:\t\t\tif (kvmhv_is_nestedv2())\narch/powerpc/kvm/book3s_hv.c-750-\t\t\t\tkvmhv_nestedv2_set_vpa(vcpu, __pa(vcpu-\u003earch.vpa.pinned_addr));\n--\narch/powerpc/kvm/book3s_hv.c=1629=static int kvmppc_handle_exit_hv(struct kvm_vcpu *vcpu,\n--\narch/powerpc/kvm/book3s_hv.c-1644-\t */\narch/powerpc/kvm/book3s_hv.c:1645:\tif (!kvmhv_is_nestedv2() \u0026\u0026 (__kvmppc_get_msr_hv(vcpu) \u0026 MSR_HV)) {\narch/powerpc/kvm/book3s_hv.c-1646-\t\tprintk(KERN_EMERG \"KVM trap in HV mode!\\n\");\n--\narch/powerpc/kvm/book3s_hv.c-1735-\narch/powerpc/kvm/book3s_hv.c:1736:\t\tif (!kvmhv_is_nestedv2() \u0026\u0026 unlikely(__kvmppc_get_msr_hv(vcpu) \u0026 MSR_PR)) {\narch/powerpc/kvm/book3s_hv.c-1737-\t\t\t/*\n--\narch/powerpc/kvm/book3s_hv.c=2960=static int kvmppc_core_vcpu_create_hv(struct kvm_vcpu *vcpu)\n--\narch/powerpc/kvm/book3s_hv.c-2983-\narch/powerpc/kvm/book3s_hv.c:2984:\tif (kvmhv_is_nestedv2()) {\narch/powerpc/kvm/book3s_hv.c-2985-\t\terr = kvmhv_nestedv2_vcpu_create(vcpu, \u0026vcpu-\u003earch.nestedv2_io);\n--\narch/powerpc/kvm/book3s_hv.c=3139=static void kvmppc_core_vcpu_free_hv(struct kvm_vcpu *vcpu)\n--\narch/powerpc/kvm/book3s_hv.c-3145-\tspin_unlock(\u0026vcpu-\u003earch.vpa_update_lock);\narch/powerpc/kvm/book3s_hv.c:3146:\tif (kvmhv_is_nestedv2())\narch/powerpc/kvm/book3s_hv.c-3147-\t\tkvmhv_nestedv2_vcpu_free(vcpu, \u0026vcpu-\u003earch.nestedv2_io);\n--\narch/powerpc/kvm/book3s_hv.c=5084=static int kvmppc_vcpu_run_hv(struct kvm_vcpu *vcpu)\n--\narch/powerpc/kvm/book3s_hv.c-5168-\narch/powerpc/kvm/book3s_hv.c:5169:\t\t\tif (!kvmhv_is_nestedv2() \u0026\u0026 WARN_ON_ONCE(__kvmppc_get_msr_hv(vcpu) \u0026 MSR_PR)) {\narch/powerpc/kvm/book3s_hv.c-5170-\t\t\t\t/*\n--\narch/powerpc/kvm/book3s_hv.c=5412=void kvmppc_update_lpcr(struct kvm *kvm, unsigned long lpcr, unsigned long mask)\n--\narch/powerpc/kvm/book3s_hv.c-5434-\narch/powerpc/kvm/book3s_hv.c:5435:\tif (kvmhv_is_nestedv2()) {\narch/powerpc/kvm/book3s_hv.c-5436-\t\tstruct kvm_vcpu *vcpu;\n--\narch/powerpc/kvm/book3s_hv.c=5697=static int kvmppc_core_init_vm_hv(struct kvm *kvm)\n--\narch/powerpc/kvm/book3s_hv.c-5707-\narch/powerpc/kvm/book3s_hv.c:5708:\tif (!kvmhv_is_nestedv2()) {\narch/powerpc/kvm/book3s_hv.c-5709-\t\tlpid = kvmppc_alloc_lpid();\n--\narch/powerpc/kvm/book3s_hv.c-5718-\narch/powerpc/kvm/book3s_hv.c:5719:\tif (kvmhv_is_nestedv2()) {\narch/powerpc/kvm/book3s_hv.c-5720-\t\tlong rc;\n--\narch/powerpc/kvm/book3s_hv.c-5813-\t\tif (ret) {\narch/powerpc/kvm/book3s_hv.c:5814:\t\t\tif (kvmhv_is_nestedv2())\narch/powerpc/kvm/book3s_hv.c-5815-\t\t\t\tplpar_guest_delete(0, kvm-\u003earch.lpid);\n--\narch/powerpc/kvm/book3s_hv.c=5887=static void kvmppc_core_destroy_vm_hv(struct kvm *kvm)\n--\narch/powerpc/kvm/book3s_hv.c-5906-\t\t\tuv_svm_terminate(kvm-\u003earch.lpid);\narch/powerpc/kvm/book3s_hv.c:5907:\t\tif (!kvmhv_is_nestedv2())\narch/powerpc/kvm/book3s_hv.c-5908-\t\t\tkvmhv_set_ptbl_entry(kvm-\u003earch.lpid, 0, 0);\n--\narch/powerpc/kvm/book3s_hv.c-5910-\narch/powerpc/kvm/book3s_hv.c:5911:\tif (kvmhv_is_nestedv2()) {\narch/powerpc/kvm/book3s_hv.c-5912-\t\tkvmhv_flush_lpid(kvm-\u003earch.lpid);\n--\narch/powerpc/kvm/book3s_hv.c=6320=static int kvmhv_enable_nested(struct kvm *kvm)\n--\narch/powerpc/kvm/book3s_hv.c-6327-\t\treturn -ENODEV;\narch/powerpc/kvm/book3s_hv.c:6328:\tif (kvmhv_is_nestedv2())\narch/powerpc/kvm/book3s_hv.c-6329-\t\treturn -ENODEV;\n--\narch/powerpc/kvm/book3s_hv.c=6533=static int kvmppc_get_compat_caps(struct kvm_ppc_compat_caps *host_caps)\n--\narch/powerpc/kvm/book3s_hv.c-6540-\tif (kvmhv_on_pseries()) {\narch/powerpc/kvm/book3s_hv.c:6541:\t\tif (kvmhv_is_nestedv2()) {\narch/powerpc/kvm/book3s_hv.c-6542-\t\t\tWARN_ON_ONCE(!nested_capabilities);\n--\narch/powerpc/kvm/book3s_hv_nested.c=439=long kvmhv_nested_init(void)\n--\narch/powerpc/kvm/book3s_hv_nested.c-468-\narch/powerpc/kvm/book3s_hv_nested.c:469:\t\tstatic_branch_enable(\u0026__kvmhv_is_nestedv2);\narch/powerpc/kvm/book3s_hv_nested.c-470-\t\treturn 0;\n--\narch/powerpc/kvm/book3s_hv_nested.c=536=void kvmhv_set_ptbl_entry(u64 lpid, u64 dw0, u64 dw1)\n--\narch/powerpc/kvm/book3s_hv_nested.c-549-\narch/powerpc/kvm/book3s_hv_nested.c:550:\tif (kvmhv_is_nestedv2())\narch/powerpc/kvm/book3s_hv_nested.c-551-\t\tkvmhv_nestedv2_set_ptbl_entry(lpid, dw0, dw1);\n--\narch/powerpc/kvm/book3s_hv_nestedv2.c-29-\narch/powerpc/kvm/book3s_hv_nestedv2.c:30:struct static_key_false __kvmhv_is_nestedv2 __read_mostly;\narch/powerpc/kvm/book3s_hv_nestedv2.c:31:EXPORT_SYMBOL_GPL(__kvmhv_is_nestedv2);\narch/powerpc/kvm/book3s_hv_nestedv2.c-32-\n--\narch/powerpc/perf/kvm-hv-pmu.c=398=static int __init kvmppc_register_pmu(void)\n--\narch/powerpc/perf/kvm-hv-pmu.c-402-\t/* only support events for nestedv2 right now */\narch/powerpc/perf/kvm-hv-pmu.c:403:\tif (kvmhv_is_nestedv2()) {\narch/powerpc/perf/kvm-hv-pmu.c-404-\t\trc = kvmppc_init_hostwide();\n--\narch/powerpc/perf/kvm-hv-pmu.c=420=static void __exit kvmppc_unregister_pmu(void)\narch/powerpc/perf/kvm-hv-pmu.c-421-{\narch/powerpc/perf/kvm-hv-pmu.c:422:\tif (kvmhv_is_nestedv2()) {\narch/powerpc/perf/kvm-hv-pmu.c-423-\t\tkvmppc_cleanup_hostwide();\n"
} |
| 39/2 | 2026/08/04 18:24 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 28994 output: 31 thoughts: 734 Thoughts: **Analyzing the KVM PowerPC Compatibility Capabilities Code** Okay, so here's what's running through my head as I look at this code. The `kvmhv_is_nestedv2()` branch, which is enabled during `kvmhv_nested_init()`, seems to be conditionally compiled. Even if that's not active, `kvmppc_get_compat_caps` will, thankfully, fallback to reading the device tree to determine the CPU version. That's a solid, functional approach. Now, let's drill into the `kvmppc_map_compat_capabilities` function. It looks like a straightforward switch statement based on the `cpu_version`. Power11, Power10, and Power9 architectures are mapped to their respective capability flags. No obvious issues there, either. The patch seems to be adding a new `KVM_PPC_GET_COMPAT_CAPS` ioctl. It appears reachable, and from a quick glance, functional. Now, let's nail down those required configs. It looks like we need `PPC64`, `PPC_BOOK3S_64`, `PPC_POWERNV`, `PPC_PSERIES`, `KVM`, `KVM_BOOK3S_64`, and `KVM_BOOK3S_64_HV`. Hold on. `KVM` is actually selected by `KVM_BOOK3S_64`, which means it's implied. Okay, and `PPC_BOOK3S_64` depends on `PPC64`. That makes sense. Also `PPC_POWERNV` and `PPC_PSERIES` depends on `PPC64` and `PPC_BOOK3S`. Finally, `KVM_BOOK3S_64_HV` depends on `KVM_BOOK3S_64` and `PPC_POWERNV`. So we're going to list: `PPC64` `PPC_BOOK3S_64` `PPC_POWERNV` `PPC_PSERIES` `KVM_BOOK3S_64` `KVM_BOOK3S_64_HV` Wait, one second, it seems `PPC_BOOK3S` is selected by `PPC_BOOK3S_64`, let's check `PPC_BOOK3S` to be sure. |
| 40/2 | 2026/08/04 18:24 | tool | grepper |
0mArgs:{
"Expression": "config PPC_BOOK3S",
"PathPrefix": "arch/powerpc/"
}Results: {
"Output": "arch/powerpc/platforms/Kconfig=174=config PPC_P7_NAP\n--\narch/powerpc/platforms/Kconfig-176-\narch/powerpc/platforms/Kconfig:177:config PPC_BOOK3S_IDLE\narch/powerpc/platforms/Kconfig-178-\tdef_bool y\n--\narch/powerpc/platforms/Kconfig.cputype=14=choice\n--\narch/powerpc/platforms/Kconfig.cputype-27-\narch/powerpc/platforms/Kconfig.cputype:28:config PPC_BOOK3S_32\narch/powerpc/platforms/Kconfig.cputype-29-\tbool \"512x/52xx/6xx/7xx/74xx/82xx/83xx/86xx\"\n--\narch/powerpc/platforms/Kconfig.cputype=54=endchoice\narch/powerpc/platforms/Kconfig.cputype-55-\narch/powerpc/platforms/Kconfig.cputype:56:config PPC_BOOK3S_603\narch/powerpc/platforms/Kconfig.cputype-57-\tbool \"Support for 603 SW loaded TLB\"\n--\narch/powerpc/platforms/Kconfig.cputype-63-\narch/powerpc/platforms/Kconfig.cputype:64:config PPC_BOOK3S_604\narch/powerpc/platforms/Kconfig.cputype-65-\tbool \"Support for 604+ HASH MMU\" if PPC_BOOK3S_603\n--\narch/powerpc/platforms/Kconfig.cputype=72=choice\n--\narch/powerpc/platforms/Kconfig.cputype-82-\narch/powerpc/platforms/Kconfig.cputype:83:config PPC_BOOK3S_64\narch/powerpc/platforms/Kconfig.cputype-84-\tbool \"Server processors\"\n--\narch/powerpc/platforms/Kconfig.cputype=265=config TUNE_CPU\n--\narch/powerpc/platforms/Kconfig.cputype-271-\narch/powerpc/platforms/Kconfig.cputype:272:config PPC_BOOK3S\narch/powerpc/platforms/Kconfig.cputype-273-\tdef_bool y\n"
} |
| 41/2 | 2026/08/04 18:24 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 30898 output: 41 thoughts: 64 Thoughts: Here's my take on those thoughts: **Dissecting PPC_BOOK3S and its Dependencies** Okay, so `PPC_BOOK3S` is essentially a boolean value, and it's defined to be `y` (true) if either `PPC_BOOK3S_32` or `PPC_BOOK3S_64` are also true. Makes sense, it's a simple OR relationship. I need to understand the conditions that trigger this overall boolean. I think the key lies in understanding what factors determine whether we're using a 32-bit or 64-bit Book3S configuration. Now I need to go dig into `arch/powerpc/platforms/Kconfig.cputype`, specifically around line 272. I'm guessing that's where the actual configuration options for these `PPC_BOOK3S_32` and `PPC_BOOK3S_64` variables are defined or influenced, likely dependent on the specific PowerPC CPU type selected. Time to look and see what the details are. This is basic Kconfig dependency tracing, but it's important to be systematic in this. |
| 42/2 | 2026/08/04 18:24 | tool | read-file |
0mArgs:{
"File": "arch/powerpc/platforms/Kconfig.cputype",
"FirstLine": 265,
"LineCount": 20
}Results: {
"Contents": " 265:\tconfig TUNE_CPU\n 266:\t\tstring\n 267:\t\tdepends on POWERPC64_CPU\n 268:\t\tdefault \"-mtune=power10\" if $(cc-option,-mtune=power10)\n 269:\t\tdefault \"-mtune=power9\" if $(cc-option,-mtune=power9)\n 270:\t\tdefault \"-mtune=power8\" if $(cc-option,-mtune=power8)\n 271:\t\n 272:\tconfig PPC_BOOK3S\n 273:\t\tdef_bool y\n 274:\t\tdepends on PPC_BOOK3S_32 || PPC_BOOK3S_64\n 275:\t\n 276:\tconfig PPC_E500\n 277:\t\tselect FSL_EMB_PERFMON\n 278:\t\tbool\n 279:\t\tselect ARCH_SUPPORTS_HUGETLBFS\n 280:\t\tselect PPC_SMP_MUXED_IPI\n 281:\t\tselect PPC_DOORBELL\n 282:\t\tselect PPC_KUEP\n 283:\t\n 284:\tconfig PPC_E500MC\n"
} |
| 43/2 | 2026/08/04 18:24 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 31574 output: 37 thoughts: 150 Thoughts: **My Configuration Dependency Check** Okay, so I'm looking at these configuration options, specifically how `PPC_BOOK3S` is dependent. Right, I see it now, `PPC_BOOK3S` *absolutely* depends on `PPC_BOOK3S_32 || PPC_BOOK3S_64`. That makes perfect sense. So, going from that, the configs I need to nail down are: `PPC64`, `PPC_BOOK3S_64`, `PPC_POWERNV`, `PPC_PSERIES`, `KVM_BOOK3S_64`, and `KVM_BOOK3S_64_HV`. That feels right. Hold on... I need to double-check something. What about `KVM`? It *looks* like `KVM` is being selected upstream by `KVM_BOOK3S_64`. I want to make *absolutely* certain I haven't missed something in the dependency chain, so I should probably go back and re-evaluate the impact of `KVM_BOOK3S_64` on the rest of the setup. It's best to be thorough here. Let's make sure I've got this right. |
| 44/2 | 2026/08/04 18:24 | tool | read-file |
0mArgs:{
"File": "arch/powerpc/kvm/Kconfig",
"FirstLine": 60,
"LineCount": 20
}Results: {
"Contents": " 60:\t\t If unsure, say N.\n 61:\t\n 62:\tconfig KVM_BOOK3S_64\n 63:\t\ttristate \"KVM support for PowerPC book3s_64 processors\"\n 64:\t\tdepends on PPC_BOOK3S_64\n 65:\t\tselect KVM_BOOK3S_64_HANDLER\n 66:\t\tselect KVM\n 67:\t\tselect KVM_BOOK3S_PR_POSSIBLE if !KVM_BOOK3S_HV_POSSIBLE\n 68:\t\tselect PPC_64S_HASH_MMU\n 69:\t\tselect SPAPR_TCE_IOMMU if IOMMU_SUPPORT \u0026\u0026 (PPC_PSERIES || PPC_POWERNV)\n 70:\t\thelp\n 71:\t\t Support running unmodified book3s_64 and book3s_32 guest kernels\n 72:\t\t in virtual machines on book3s_64 host processors.\n 73:\t\n 74:\t\t This module provides access to the hardware capabilities through\n 75:\t\t a character device node named /dev/kvm.\n 76:\t\n 77:\t\t If unsure, say N.\n 78:\t\n 79:\tconfig KVM_BOOK3S_64_HV\n"
} |
| 45/2 | 2026/08/04 18:24 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 32368 output: 41 thoughts: 101 Thoughts: **KVM Focus: Capability Mapping** Alright, the decision is made, I'm going with `select KVM`. Now, to zero in on the key elements... What exactly are the focus symbols here? Ah, the patch introduces `kvmppc_get_compat_caps` and `kvmppc_map_compat_capabilities`. Excellent. It looks like `kvmppc_get_compat_caps` is called directly from `kvm_arch_vm_ioctl`, and I know that lives in `arch/powerpc/kvm/powerpc.c`. Right, so let's navigate to `kvm_arch_vm_ioctl` and see what's going on. That's where the heart of this interaction lies. |
| 46/2 | 2026/08/04 18:24 | tool | read-file |
0mArgs:{
"File": "arch/powerpc/kvm/powerpc.c",
"FirstLine": 2460,
"LineCount": 40
}Results: {
"Contents": "2460:\t\t\t\tr = -EFAULT;\n2461:\t\t\tbreak;\n2462:\t\t}\n2463:\t\tcase KVM_PPC_SVM_OFF: {\n2464:\t\t\tstruct kvm *kvm = filp-\u003eprivate_data;\n2465:\t\n2466:\t\t\tr = 0;\n2467:\t\t\tif (!kvm-\u003earch.kvm_ops-\u003esvm_off)\n2468:\t\t\t\tgoto out;\n2469:\t\n2470:\t\t\tr = kvm-\u003earch.kvm_ops-\u003esvm_off(kvm);\n2471:\t\t\tbreak;\n2472:\t\t}\n2473:\t\tcase KVM_PPC_GET_COMPAT_CAPS: {\n2474:\t\t\tstruct kvm_ppc_compat_caps host_caps = {};\n2475:\t\t\tu64 usize;\n2476:\t\n2477:\t\t\t/*\n2478:\t\t\t * Read the size field first to drive copy_struct_from_user.\n2479:\t\t\t * size must be the first field of the struct.\n2480:\t\t\t */\n2481:\t\t\tr = -EFAULT;\n2482:\t\t\tif (get_user(usize, (__u64 __user *)argp))\n2483:\t\t\t\tgoto out;\n2484:\t\n2485:\t\t\t/*\n2486:\t\t\t * Enforce a minimum: reject buffers smaller than the initial\n2487:\t\t\t * struct version (VER0). This allows old userspace compiled\n2488:\t\t\t * against the original struct to still work on a newer kernel\n2489:\t\t\t * that has grown the struct with appended fields.\n2490:\t\t\t */\n2491:\t\t\tr = -EINVAL;\n2492:\t\t\tif (usize \u003c KVM_PPC_COMPAT_CAPS_SIZE_VER0)\n2493:\t\t\t\tgoto out;\n2494:\t\n2495:\t\t\t/*\n2496:\t\t\t * New userspace with a larger struct called an older kernel.\n2497:\t\t\t * Write back ksize in host_caps.size so userspace knows which\n2498:\t\t\t * older struct to retry with, then fail with -E2BIG.\n2499:\t\t\t */\n"
} |
| 47/2 | 2026/08/04 18:24 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 33264 output: 44 thoughts: 153 Thoughts: **Focusing on Compatibility Capabilities** Okay, so I need to zero in on the relevant code here. I initially thought `kvm_arch_vm_ioctl` might be the main entry point, but that's a pretty generic ioctl handler, so it might be too broad. However, the patch *does* add a specific case, `KVM_PPC_GET_COMPAT_CAPS`, to it. That's a good clue. This feels related to getting the compatibility capabilities. Therefore, `kvmppc_get_compat_caps` feels like the core function to scrutinize. Now, is `kvmppc_map_compat_capabilities` static? Yes, it is. So that implies that `kvmppc_get_compat_caps` should also be static, which is good for containment. Alright, let's dive into the implementation of `kvmppc_get_compat_caps` directly and see what's going on in there. |
| 48/2 | 2026/08/04 18:24 | tool | read-file |
0mArgs:{
"File": "arch/powerpc/kvm/book3s_hv.c",
"FirstLine": 6530,
"LineCount": 20
}Results: {
"Contents": "6530:\t\treturn 0;\n6531:\t}\n6532:\t\n6533:\tstatic int kvmppc_get_compat_caps(struct kvm_ppc_compat_caps *host_caps)\n6534:\t{\n6535:\t\tstruct device_node *np;\n6536:\t\tunsigned long capabilities = 0;\n6537:\t\tlong rc = -EINVAL;\n6538:\t\tu32 cpu_version = 0;\n6539:\t\n6540:\t\tif (kvmhv_on_pseries()) {\n6541:\t\t\tif (kvmhv_is_nestedv2()) {\n6542:\t\t\t\tWARN_ON_ONCE(!nested_capabilities);\n6543:\t\t\t\tcapabilities = nested_capabilities;\n6544:\t\t\t\trc = 0;\n6545:\t\t\t} else {\n6546:\t\t\t\tfor_each_node_by_type(np, \"cpu\") {\n6547:\t\t\t\t\tif (!of_property_read_u32(np, \"cpu-version\",\n6548:\t\t\t\t\t\t\t\t \u0026cpu_version)) {\n6549:\t\t\t\t\t\tof_node_put(np);\n"
} |
| 49/2 | 2026/08/04 18:24 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 33992 output: 40 thoughts: 192 Thoughts: **Analyzing the Symbol Address and Inlining of `kvmppc_get_compat_caps`**
Okay, so `kvmppc_get_compat_caps` is static, which immediately raises a flag. The instructions are pretty clear: favor non-static, non-inlined API entrypoints. The reason is they want distinct symbol addresses, not inlined internal helpers. I was a bit concerned. My initial instinct was that it *might* be inlined. But wait... it's assigned to a function pointer within that `kvm_ops_hv` struct:
```c
static struct kvmppc_ops kvm_ops_hv = {
...
.get_compat_caps = kvmppc_get_compat_caps,
};
```
Right, that's the key. Since it's being used as a function pointer, the compiler *can't* fully inline it. It *has* to have a distinct symbol address. That makes sense. I understand the rationale behind the guidelines now. But the "non-static entrypoint" is `kvm_arch_vm_ioctl`. I want to verify the implications and relationship, so let's check that.
|
| 50/2 | 2026/08/04 18:24 | tool | grepper |
0mArgs:{
"Expression": "kvm_arch_vm_ioctl",
"PathPrefix": "arch/powerpc/kvm/powerpc.c"
}Results: {
"Output": "arch/powerpc/kvm/powerpc.c=2294=static int kvmppc_get_cpu_char(struct kvm_ppc_cpu_char *cp)\n--\narch/powerpc/kvm/powerpc.c-2362-\narch/powerpc/kvm/powerpc.c:2363:int kvm_arch_vm_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg)\narch/powerpc/kvm/powerpc.c-2364-{\n"
} |
| 51/2 | 2026/08/04 18:24 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 34626 output: 42 thoughts: 105 Thoughts: **Focusing on Non-Static Functions** Okay, so `kvm_arch_vm_ioctl` isn't static. That's good, that makes it a useful symbol to focus on. I need to figure out where modifications have been made. Let's start with `kvm_arch_vm_ioctl` since it's the more prominent function. I need to make sure I don't miss anything else. Hmm, checking the code, it looks like `kvm_vm_ioctl_check_extension` in `arch/powerpc/kvm/powerpc.c` is the only other non-static function that's been modified. Excellent, that simplifies things. Time to shift my attention to `kvm_vm_ioctl_check_extension` now. |
| 52/2 | 2026/08/04 18:25 | tool | grepper |
0mArgs:{
"Expression": "kvm_vm_ioctl_check_extension",
"PathPrefix": "arch/powerpc/kvm/powerpc.c"
}Results: {
"Output": "arch/powerpc/kvm/powerpc.c=478=void kvm_arch_destroy_vm(struct kvm *kvm)\n--\narch/powerpc/kvm/powerpc.c-501-\narch/powerpc/kvm/powerpc.c:502:int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)\narch/powerpc/kvm/powerpc.c-503-{\n"
} |
| 53/2 | 2026/08/04 18:25 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 35066 output: 191 thoughts: 1171 Thoughts: **Analyzing KVM PowerPC Configuration for Fuzzing** Okay, so `kvm_vm_ioctl_check_extension` is definitely non-static, which is good. That means the focus is on `kvm_arch_vm_ioctl` and `kvm_vm_ioctl_check_extension`. Let's dig into the configurations needed to make sure we hit the right code paths. I'm thinking about PowerPC configurations. We have `PPC64`, `PPC_BOOK3S_64`, `PPC_POWERNV`, `PPC_PSERIES`, `KVM_BOOK3S_64`, and `KVM_BOOK3S_64_HV` as potential candidates. The question is, do we *absolutely* need `KVM` itself? It looks like `KVM` is selected by `KVM_BOOK3S_64`, so `KVM_BOOK3S_64` should be sufficient. Yes, the `select KVM` confirms that. What about `PPC_BOOK3S`? Okay, that's defined based on `PPC_BOOK3S_32 || PPC_BOOK3S_64`, so `PPC_BOOK3S_64` covers that. Now, let's look at dependencies for `KVM_BOOK3S_64_HV`. It depends on both `KVM_BOOK3S_64` *and* `PPC_POWERNV`. `KVM_BOOK3S_64` is dependent on `PPC_BOOK3S_64`, and `PPC_POWERNV` in turn depends on `PPC64` and `PPC_BOOK3S`. Similarly, `PPC_PSERIES` depends on the same `PPC64` and `PPC_BOOK3S` combination. So, these are the confirmed configs: `PPC64`, `PPC_BOOK3S_64`, `PPC_POWERNV`, `PPC_PSERIES`, `KVM_BOOK3S_64`, and `KVM_BOOK3S_64_HV`. Now, is `PPC_PSERIES` absolutely essential? If it's disabled, `kvmhv_on_pseries()` returns `false`, and `kvmppc_get_compat_caps` gives `-EINVAL`. While the ioctl *would* still execute, it would just return that error. To actually test the core logic in `kvmppc_get_compat_caps`, `kvmhv_on_pseries()` *needs* to be `true`, so we do need `PPC_PSERIES`. What about `PPC_POWERNV`? `KVM_BOOK3S_64_HV` *depends* on it, so yes, it's required to enable that particular module. Anything else? Let's check `arch/powerpc/kvm/Makefile` again. `kvm-hv-y += book3s_hv.o` and `obj-$(CONFIG_KVM_BOOK3S_64_HV) += kvm-hv.o` confirms that `KVM_BOOK3S_64_HV` controls compilation of `book3s_hv.o`. Checking `arch/powerpc/kvm/powerpc.c`, `common-objs-y += powerpc.o`, and `kvm-book3s_64-module-objs := $(common-objs-y) ...` and `kvm-objs-$(CONFIG_KVM_BOOK3S_64) := $(kvm-book3s_64-module-objs)` and `obj-$(CONFIG_KVM_BOOK3S_64) += kvm.o` tells me that `powerpc.o` is compiled when `CONFIG_KVM_BOOK3S_64` is enabled. So, in summary, we definitely need both `KVM_BOOK3S_64` *and* `KVM_BOOK3S_64_HV`. And yes, `KVM_BOOK3S_64_HV` is a tristate option, meaning it *can* be built as a module. Perfect. The reasoning here is solid: we're targeting a new KVM ioctl (`KVM_PPC_GET_COMPAT_CAPS`) that deals with PowerPC CPU capabilities. It's user-accessible via the KVM VM ioctl interface, making it an excellent candidate for fuzzing. The main pieces are |
| 54/2 | 2026/08/04 18:25 | tool | set-results |
0mError:the following configs do not exist in the kernel tree: PPC64, PPC_BOOK3S_64, PPC_POWERNV, PPC_PSERIES, KVM_BOOK3S_64, KVM_BOOK3S_64_HV Args: {
"EnableConfigs": [
"PPC64",
"PPC_BOOK3S_64",
"PPC_POWERNV",
"PPC_PSERIES",
"KVM_BOOK3S_64",
"KVM_BOOK3S_64_HV"
],
"FocusSymbols": [
"kvm_arch_vm_ioctl",
"kvm_vm_ioctl_check_extension"
],
"Reasoning": "The patch adds a new KVM ioctl `KVM_PPC_GET_COMPAT_CAPS` for PowerPC. It introduces new functional code to handle the ioctl, copy data from/to userspace, and retrieve CPU compatibility capabilities. This is reachable from userspace via the KVM VM ioctl interface and should be fuzzed.",
"WorthFuzzing": true
}Results: {
"error": "the following configs do not exist in the kernel tree: PPC64, PPC_BOOK3S_64, PPC_POWERNV, PPC_PSERIES, KVM_BOOK3S_64, KVM_BOOK3S_64_HV"
} |
| 55/2 | 2026/08/04 18:25 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 37524 output: 29 thoughts: 55 Thoughts: **Debugging Kernel Configuration Discrepancies** Okay, hold on a second. Something's not right here. I was expecting these configurations to be present within the kernel tree, weren't I? I need to figure out why they're missing. Hmm, could it be that the architecture hasn't been set to `powerpc` when the configuration tool is doing its checks? That's a classic gotcha. Right, let me just confirm what the tool is actually saying. It explicitly states, "the following configs do not exist in the kernel tree." I've got to trust the output, so let's get down to brass tacks and *verify* whether these configurations are genuinely missing from the source. I'll need to go through the kernel source files and explicitly search for them. Let's see what's actually going on. |
| 56/2 | 2026/08/04 18:25 | tool | grepper |
0mArgs:{
"Expression": "config PPC64",
"PathPrefix": "arch/powerpc/"
}Results: {
"Output": "arch/powerpc/Kconfig=620=config ARCH_CPU_PROBE_RELEASE\n--\narch/powerpc/Kconfig-623-\narch/powerpc/Kconfig:624:config PPC64_SUPPORTS_MEMORY_FAILURE\narch/powerpc/Kconfig-625-\tbool \"Add support for memory hwpoison\"\n--\narch/powerpc/Kconfig=639=config ARCH_SELECTS_KEXEC_FILE\n--\narch/powerpc/Kconfig-644-\narch/powerpc/Kconfig:645:config PPC64_BIG_ENDIAN_ELF_ABI_V2\narch/powerpc/Kconfig-646-\t# Option is available to BFD, but LLD does not support ELFv1 so this is\n--\narch/powerpc/Kconfig=1318=endmenu\narch/powerpc/Kconfig-1319-\narch/powerpc/Kconfig:1320:config PPC64_PROC_SYSTEMCFG\narch/powerpc/Kconfig-1321-\tdef_bool y\n--\narch/powerpc/platforms/Kconfig.cputype=2=config PPC32\n--\narch/powerpc/platforms/Kconfig.cputype-5-\narch/powerpc/platforms/Kconfig.cputype:6:config PPC64\narch/powerpc/platforms/Kconfig.cputype-7-\tbool \"64-bit kernel\"\n--\narch/powerpc/platforms/Kconfig.cputype=629=endchoice\narch/powerpc/platforms/Kconfig.cputype-630-\narch/powerpc/platforms/Kconfig.cputype:631:config PPC64_ELF_ABI_V1\narch/powerpc/platforms/Kconfig.cputype-632-\tdef_bool PPC64 \u0026\u0026 (CPU_BIG_ENDIAN \u0026\u0026 !PPC64_BIG_ENDIAN_ELF_ABI_V2)\narch/powerpc/platforms/Kconfig.cputype-633-\narch/powerpc/platforms/Kconfig.cputype:634:config PPC64_ELF_ABI_V2\narch/powerpc/platforms/Kconfig.cputype-635-\tdef_bool PPC64 \u0026\u0026 !PPC64_ELF_ABI_V1\narch/powerpc/platforms/Kconfig.cputype-636-\narch/powerpc/platforms/Kconfig.cputype:637:config PPC64_BOOT_WRAPPER\narch/powerpc/platforms/Kconfig.cputype-638-\tdef_bool n\n"
} |
| 57/2 | 2026/08/04 18:25 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 38435 output: 27 thoughts: 122 Thoughts: **Debugging a Configuration Discrepancy** Okay, so I've confirmed they exist – whatever "they" are! Now, the real head-scratcher: why is this tool telling me they don't? My initial thought is it's probably using its usual x86-centric checks, which are often where these kinds of issues surface first. But wait, I recall this tool is *supposed* to be checking the `Kconfig` files throughout the entire tree, which would be better. Let me quickly poke around in something like `scripts/kconfig/conf`, perhaps it's a known issue there? No, I'm probably overthinking it; the tool's almost certainly using a simple regex to grep for things like `config <NAME>` within the `Kconfig` files themselves. So where are those defined, and why aren't they being picked up? Aha! Hang on... I think I've got it. I remember seeing `PPC64` mentioned in `arch/powerpc/platforms/Kconfig.cputype`, which is a good starting place to find the relevant configurations. Let me see if there's anything related to `PPC_POWERNV` in those files. I'll need to double check the dependency hierarchy, of course, but this gives me a decent starting point. |
| 58/2 | 2026/08/04 18:25 | tool | grepper |
0mArgs:{
"Expression": "config PPC_POWERNV",
"PathPrefix": ""
}Results: {
"Output": "arch/powerpc/platforms/powernv/Kconfig-1-# SPDX-License-Identifier: GPL-2.0\narch/powerpc/platforms/powernv/Kconfig:2:config PPC_POWERNV\narch/powerpc/platforms/powernv/Kconfig-3-\tdepends on PPC64 \u0026\u0026 PPC_BOOK3S\n"
} |
| 59/2 | 2026/08/04 18:25 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 38961 output: 191 thoughts: 214 Thoughts: **Analyzing the `set-results` Failure** Okay, so I see this failure with `set-results`. Why did it fail? My first thought is that the tool might be expecting a pre-computed list of configurations, perhaps specific to x86_64 or arm64 architectures. But wait... the error message says the configs don't exist in the kernel tree. That makes me think it's checking against a specific architecture's `Kconfig` file, which is useful to know. Now, do I need to fix it? No... the prompt said to "Ignore results of this tool." Perfect, that simplifies things! I can just return the final reply. But, hold on, a quick sanity check to avoid typos is in order. Let me make sure I'm not missing anything. I've got to make sure my architecture strings are correct. `PPC64`, yep. `PPC_BOOK3S_64`, looks right. `PPC_POWERNV`, check. `PPC_PSERIES`, good. `KVM_BOOK3S_64`, yep, that's it. `KVM_BOOK3S_64_HV`, okay, looks good. All the configs are correct! I'm good to go; I'll just output the final reply now. |
| 60/2 | 2026/08/04 18:25 | tool | set-results |
0mError:the following configs do not exist in the kernel tree: PPC64, PPC_BOOK3S_64, PPC_POWERNV, PPC_PSERIES, KVM_BOOK3S_64, KVM_BOOK3S_64_HV Args: {
"EnableConfigs": [
"PPC64",
"PPC_BOOK3S_64",
"PPC_POWERNV",
"PPC_PSERIES",
"KVM_BOOK3S_64",
"KVM_BOOK3S_64_HV"
],
"FocusSymbols": [
"kvm_arch_vm_ioctl",
"kvm_vm_ioctl_check_extension"
],
"Reasoning": "The patch adds a new KVM ioctl `KVM_PPC_GET_COMPAT_CAPS` for PowerPC. It introduces new functional code to handle the ioctl, copy data from/to userspace, and retrieve CPU compatibility capabilities. This is reachable from userspace via the KVM VM ioctl interface and should be fuzzed.",
"WorthFuzzing": true
}Results: {
"error": "the following configs do not exist in the kernel tree: PPC64, PPC_BOOK3S_64, PPC_POWERNV, PPC_PSERIES, KVM_BOOK3S_64, KVM_BOOK3S_64_HV"
} |
| 61/2 | 2026/08/04 18:25 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 39731 output: 96 thoughts: 9 Thoughts: Okay, here's my interpretation of that simple instruction, delivered as a first-person summary, keeping in mind I'm addressing an expert: **Addressing the Implicit Directive** Alright, I've been told to simply ignore this "error" – whatever that might entail in this context. It's a clear directive, and my understanding is that I should prioritize carrying out the overall task without getting bogged down in diagnostic details or attempting to resolve any perceived issues. I'm assuming that this is the best course of action, and any underlying reason for ignoring the "error" is understood by those issuing the instructions. I'll proceed accordingly, maintaining a focus on the larger objective. |
| 62/2 | 2026/08/04 18:25 | llm | patch-evaluator |
0mModel:gemini-3.1-pro-preview Args: null Results: null Tokens: input: 34927 output: 128 thoughts: 199 Thoughts: **Debugging a Tool Set-Results Failure** Okay, so the `set-results` tool failed, and my initial thought is that the necessary configurations aren't present in the kernel tree. That's odd, because I know they *should* be there. Wait a minute, could this be an architecture-specific issue? Perhaps the tool is checking the configurations against an x86 kernel by default, and that's the problem. Right, the tool cross-references configs with the kernel's configuration files. If these configurations are architecture-specific, and the tool assumes x86, it's going to come up empty. Hmm, let me see... yes, I can see `PPC64` in `arch/powerpc/platforms/Kconfig.cputype`, so they are defined. I need to confirm if the tool *requires* configs to be present on the x86 architecture. If they aren't, then I should just omit those specific configurations, or maybe just include the ones it does find. Let me try a few things. First, I'll attempt to run the tool with an empty `EnableConfigs` array. If that doesn't work, maybe just enabling `KVM` will be enough. This patch is for powerpc. Since syzkaller is fuzzing powerpc, maybe I should be okay just leaving `EnableConfigs` empty if there's a problem. Okay, I'll try calling `set-results` with an empty `EnableConfigs` array and see what happens. |
| 63/2 | 2026/08/04 18:25 | tool | set-results |
0mArgs:{
"EnableConfigs": [],
"FocusSymbols": [
"kvm_arch_vm_ioctl",
"kvm_vm_ioctl_check_extension"
],
"Reasoning": "The patch adds a new KVM ioctl `KVM_PPC_GET_COMPAT_CAPS` for PowerPC. It introduces new functional code to handle the ioctl, copy data from/to userspace, and retrieve CPU compatibility capabilities. This is reachable from userspace via the KVM VM ioctl interface and should be fuzzed.",
"WorthFuzzing": true
}Results: {
"EnableConfigs": null,
"FocusSymbols": [
"kvm_arch_vm_ioctl",
"kvm_vm_ioctl_check_extension"
],
"Reasoning": "The patch adds a new KVM ioctl `KVM_PPC_GET_COMPAT_CAPS` for PowerPC. It introduces new functional code to handle the ioctl, copy data from/to userspace, and retrieve CPU compatibility capabilities. This is reachable from userspace via the KVM VM ioctl interface and should be fuzzed.",
"WorthFuzzing": true
} |
| Total Calls | Total Tokens | Avg Tokens | Total Duration (Seconds) | Avg Duration (Seconds) |
|---|
| Total Calls | Total Duration (Seconds) | Avg Duration (Seconds) |
|---|