From: Chao Gao The core kernel registers a CPU hotplug callback to do VMX and TDX init and deinit while KVM registers a separate CPU offline callback to block offlining the last online CPU in a socket. Splitting TDX-related CPU hotplug handling across two components is odd and adds unnecessary complexity. Consolidate TDX-related CPU hotplug handling by integrating KVM's tdx_offline_cpu() to the one in the core kernel. Also move nr_configured_hkid to the core kernel because tdx_offline_cpu() references it. Since HKID allocation and free are handled in the core kernel, it's more natural to track used HKIDs there. Signed-off-by: Chao Gao Signed-off-by: Sean Christopherson --- arch/x86/kvm/vmx/tdx.c | 67 +------------------------------------ arch/x86/virt/vmx/tdx/tdx.c | 49 +++++++++++++++++++++++++-- 2 files changed, 47 insertions(+), 69 deletions(-) diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c index d0161dc3d184..d9dd6070baa0 100644 --- a/arch/x86/kvm/vmx/tdx.c +++ b/arch/x86/kvm/vmx/tdx.c @@ -59,8 +59,6 @@ module_param_named(tdx, enable_tdx, bool, 0444); #define TDX_SHARED_BIT_PWL_5 gpa_to_gfn(BIT_ULL(51)) #define TDX_SHARED_BIT_PWL_4 gpa_to_gfn(BIT_ULL(47)) -static enum cpuhp_state tdx_cpuhp_state __ro_after_init; - static const struct tdx_sys_info *tdx_sysinfo; void tdh_vp_rd_failed(struct vcpu_tdx *tdx, char *uclass, u32 field, u64 err) @@ -219,8 +217,6 @@ static int init_kvm_tdx_caps(const struct tdx_sys_info_td_conf *td_conf, */ static DEFINE_MUTEX(tdx_lock); -static atomic_t nr_configured_hkid; - static bool tdx_operand_busy(u64 err) { return (err & TDX_SEAMCALL_STATUS_MASK) == TDX_OPERAND_BUSY; @@ -268,7 +264,6 @@ static inline void tdx_hkid_free(struct kvm_tdx *kvm_tdx) { tdx_guest_keyid_free(kvm_tdx->hkid); kvm_tdx->hkid = -1; - atomic_dec(&nr_configured_hkid); misc_cg_uncharge(MISC_CG_RES_TDX, kvm_tdx->misc_cg, 1); put_misc_cg(kvm_tdx->misc_cg); kvm_tdx->misc_cg = NULL; @@ -2399,8 +2394,6 @@ static int __tdx_td_init(struct kvm *kvm, struct td_params *td_params, ret = -ENOMEM; - atomic_inc(&nr_configured_hkid); - tdr_page = alloc_page(GFP_KERNEL); if (!tdr_page) goto free_hkid; @@ -3302,51 +3295,10 @@ int tdx_gmem_max_mapping_level(struct kvm *kvm, kvm_pfn_t pfn, bool is_private) return PG_LEVEL_4K; } -static int tdx_online_cpu(unsigned int cpu) -{ - return 0; -} - -static int tdx_offline_cpu(unsigned int cpu) -{ - int i; - - /* No TD is running. Allow any cpu to be offline. */ - if (!atomic_read(&nr_configured_hkid)) - return 0; - - /* - * In order to reclaim TDX HKID, (i.e. when deleting guest TD), need to - * call TDH.PHYMEM.PAGE.WBINVD on all packages to program all memory - * controller with pconfig. If we have active TDX HKID, refuse to - * offline the last online cpu. - */ - for_each_online_cpu(i) { - /* - * Found another online cpu on the same package. - * Allow to offline. - */ - if (i != cpu && topology_physical_package_id(i) == - topology_physical_package_id(cpu)) - return 0; - } - - /* - * This is the last cpu of this package. Don't offline it. - * - * Because it's hard for human operator to understand the - * reason, warn it. - */ -#define MSG_ALLPKG_ONLINE \ - "TDX requires all packages to have an online CPU. Delete all TDs in order to offline all CPUs of a package.\n" - pr_warn_ratelimited(MSG_ALLPKG_ONLINE); - return -EBUSY; -} - static int __init __tdx_bringup(void) { const struct tdx_sys_info_td_conf *td_conf; - int r, i; + int i; for (i = 0; i < ARRAY_SIZE(tdx_uret_msrs); i++) { /* @@ -3414,23 +3366,7 @@ static int __init __tdx_bringup(void) if (misc_cg_set_capacity(MISC_CG_RES_TDX, tdx_get_nr_guest_keyids())) return -EINVAL; - /* - * TDX-specific cpuhp callback to disallow offlining the last CPU in a - * packing while KVM is running one or more TDs. Reclaiming HKIDs - * requires doing PAGE.WBINVD on every package, i.e. offlining all CPUs - * of a package would prevent reclaiming the HKID. - */ - r = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "kvm/cpu/tdx:online", - tdx_online_cpu, tdx_offline_cpu); - if (r < 0) - goto err_cpuhup; - - tdx_cpuhp_state = r; return 0; - -err_cpuhup: - misc_cg_set_capacity(MISC_CG_RES_TDX, 0); - return r; } int __init tdx_bringup(void) @@ -3486,7 +3422,6 @@ void tdx_cleanup(void) return; misc_cg_set_capacity(MISC_CG_RES_TDX, 0); - cpuhp_remove_state(tdx_cpuhp_state); } void __init tdx_hardware_setup(void) diff --git a/arch/x86/virt/vmx/tdx/tdx.c b/arch/x86/virt/vmx/tdx/tdx.c index d49645797fe4..5cf008bffa94 100644 --- a/arch/x86/virt/vmx/tdx/tdx.c +++ b/arch/x86/virt/vmx/tdx/tdx.c @@ -58,6 +58,8 @@ static LIST_HEAD(tdx_memlist); static struct tdx_sys_info tdx_sysinfo __ro_after_init; static bool tdx_module_initialized __ro_after_init; +static atomic_t nr_configured_hkid; + typedef void (*sc_err_func_t)(u64 fn, u64 err, struct tdx_module_args *args); static inline void seamcall_err(u64 fn, u64 err, struct tdx_module_args *args) @@ -190,6 +192,40 @@ static int tdx_online_cpu(unsigned int cpu) static int tdx_offline_cpu(unsigned int cpu) { + int i; + + /* No TD is running. Allow any cpu to be offline. */ + if (!atomic_read(&nr_configured_hkid)) + goto done; + + /* + * In order to reclaim TDX HKID, (i.e. when deleting guest TD), need to + * call TDH.PHYMEM.PAGE.WBINVD on all packages to program all memory + * controller with pconfig. If we have active TDX HKID, refuse to + * offline the last online cpu. + */ + for_each_online_cpu(i) { + /* + * Found another online cpu on the same package. + * Allow to offline. + */ + if (i != cpu && topology_physical_package_id(i) == + topology_physical_package_id(cpu)) + goto done; + } + + /* + * This is the last cpu of this package. Don't offline it. + * + * Because it's hard for human operator to understand the + * reason, warn it. + */ +#define MSG_ALLPKG_ONLINE \ + "TDX requires all packages to have an online CPU. Delete all TDs in order to offline all CPUs of a package.\n" + pr_warn_ratelimited(MSG_ALLPKG_ONLINE); + return -EBUSY; + +done: x86_virt_put_cpu(X86_FEATURE_VMX); return 0; } @@ -1506,15 +1542,22 @@ EXPORT_SYMBOL_GPL(tdx_get_nr_guest_keyids); int tdx_guest_keyid_alloc(void) { - return ida_alloc_range(&tdx_guest_keyid_pool, tdx_guest_keyid_start, - tdx_guest_keyid_start + tdx_nr_guest_keyids - 1, - GFP_KERNEL); + int ret; + + ret = ida_alloc_range(&tdx_guest_keyid_pool, tdx_guest_keyid_start, + tdx_guest_keyid_start + tdx_nr_guest_keyids - 1, + GFP_KERNEL); + if (ret >= 0) + atomic_inc(&nr_configured_hkid); + + return ret; } EXPORT_SYMBOL_GPL(tdx_guest_keyid_alloc); void tdx_guest_keyid_free(unsigned int keyid) { ida_free(&tdx_guest_keyid_pool, keyid); + atomic_dec(&nr_configured_hkid); } EXPORT_SYMBOL_GPL(tdx_guest_keyid_free); -- 2.52.0.223.gf5cc29aaa4-goog