From: Sean Christopherson Date: Wed, 6 Aug 2025 19:56:47 +0000 (-0700) Subject: KVM: x86: Use KVM_REQ_RECALC_INTERCEPTS to react to CPUID updates X-Git-Tag: v6.18-rc1~55^2~6^2~6 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=5a1a726e68ff256f564cf51ad21a96bceb4dd954;p=thirdparty%2Flinux.git KVM: x86: Use KVM_REQ_RECALC_INTERCEPTS to react to CPUID updates Defer recalculating MSR and instruction intercepts after a CPUID update via RECALC_INTERCEPTS to converge on RECALC_INTERCEPTS as the "official" mechanism for triggering recalcs. As a bonus, because KVM does a "recalc" during vCPU creation, and every functional VMM sets CPUID at least once, for all intents and purposes this saves at least one recalc. Tested-by: Xudong Hao Link: https://lore.kernel.org/r/20250806195706.1650976-26-seanjc@google.com Signed-off-by: Sean Christopherson --- diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index ad6cadf09930..efee08fad72e 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -448,6 +448,8 @@ void kvm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu) * adjustments to the reserved GPA bits. */ kvm_mmu_after_set_cpuid(vcpu); + + kvm_make_request(KVM_REQ_RECALC_INTERCEPTS, vcpu); } int cpuid_query_maxphyaddr(struct kvm_vcpu *vcpu) diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 711f160113d1..22c5e4ffa132 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -1225,7 +1225,7 @@ static void init_vmcb(struct kvm_vcpu *vcpu) svm_hv_init_vmcb(vmcb); - svm_recalc_intercepts(vcpu); + kvm_make_request(KVM_REQ_RECALC_INTERCEPTS, vcpu); vmcb_mark_all_dirty(vmcb); @@ -4478,8 +4478,6 @@ static void svm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu) if (sev_guest(vcpu->kvm)) sev_vcpu_after_set_cpuid(svm); - - svm_recalc_intercepts(vcpu); } static bool svm_has_wbinvd_exit(void) diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 68bec421f3fc..6b9523ca082c 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -7806,9 +7806,6 @@ void vmx_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu) vmx->msr_ia32_feature_control_valid_bits &= ~FEAT_CTL_SGX_LC_ENABLED; - /* Recalc MSR interception to account for feature changes. */ - vmx_recalc_intercepts(vcpu); - /* Refresh #PF interception to account for MAXPHYADDR changes. */ vmx_update_exception_bitmap(vcpu); }