From: Sean Christopherson Date: Thu, 28 Nov 2024 01:34:12 +0000 (-0800) Subject: KVM: x86: Avoid double CPUID lookup when updating MWAIT at runtime X-Git-Tag: v6.14-rc1~94^2~4^2~23 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=963180ae06373c9b0d16c23491bf3bcafef1900b;p=thirdparty%2Fkernel%2Flinux.git KVM: x86: Avoid double CPUID lookup when updating MWAIT at runtime Move the handling of X86_FEATURE_MWAIT during CPUID runtime updates to utilize the lookup done for other CPUID.0x1 features. No functional change intended. Reviewed-by: Maxim Levitsky Reviewed-by: Binbin Wu Reviewed-by: Xiaoyao Li Link: https://lore.kernel.org/r/20241128013424.4096668-46-seanjc@google.com Signed-off-by: Sean Christopherson --- diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index b02f5098108ab..688c7c36c73bb 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -304,6 +304,11 @@ void kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu) cpuid_entry_change(best, X86_FEATURE_APIC, vcpu->arch.apic_base & MSR_IA32_APICBASE_ENABLE); + + if (!kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_MISC_ENABLE_NO_MWAIT)) + cpuid_entry_change(best, X86_FEATURE_MWAIT, + vcpu->arch.ia32_misc_enable_msr & + MSR_IA32_MISC_ENABLE_MWAIT); } best = kvm_find_cpuid_entry_index(vcpu, 7, 0); @@ -319,14 +324,6 @@ void kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu) if (best && (cpuid_entry_has(best, X86_FEATURE_XSAVES) || cpuid_entry_has(best, X86_FEATURE_XSAVEC))) best->ebx = xstate_required_size(vcpu->arch.xcr0, true); - - if (!kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_MISC_ENABLE_NO_MWAIT)) { - best = kvm_find_cpuid_entry(vcpu, 0x1); - if (best) - cpuid_entry_change(best, X86_FEATURE_MWAIT, - vcpu->arch.ia32_misc_enable_msr & - MSR_IA32_MISC_ENABLE_MWAIT); - } } EXPORT_SYMBOL_GPL(kvm_update_cpuid_runtime);