From 183bdd161c2b773a62f01d1c030f5a3a5b7c33b5 Mon Sep 17 00:00:00 2001 From: Binbin Wu Date: Wed, 13 Sep 2023 20:42:24 +0800 Subject: [PATCH] KVM: x86: Use KVM-governed feature framework to track "LAM enabled" Use the governed feature framework to track if Linear Address Masking (LAM) is "enabled", i.e. if LAM can be used by the guest. Using the framework to avoid the relative expensive call guest_cpuid_has() during cr3 and vmexit handling paths for LAM. No functional change intended. Signed-off-by: Binbin Wu Tested-by: Xuelian Guo Link: https://lore.kernel.org/r/20230913124227.12574-14-binbin.wu@linux.intel.com Signed-off-by: Sean Christopherson --- arch/x86/kvm/cpuid.h | 3 +-- arch/x86/kvm/governed_features.h | 1 + arch/x86/kvm/mmu.h | 3 +-- arch/x86/kvm/vmx/vmx.c | 1 + 4 files changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/x86/kvm/cpuid.h b/arch/x86/kvm/cpuid.h index e4bd59c15a2ca..856e3037e74f3 100644 --- a/arch/x86/kvm/cpuid.h +++ b/arch/x86/kvm/cpuid.h @@ -276,8 +276,7 @@ static __always_inline bool guest_can_use(struct kvm_vcpu *vcpu, static inline bool kvm_vcpu_is_legal_cr3(struct kvm_vcpu *vcpu, unsigned long cr3) { - if (kvm_cpu_cap_has(X86_FEATURE_LAM) && - guest_cpuid_has(vcpu, X86_FEATURE_LAM)) + if (guest_can_use(vcpu, X86_FEATURE_LAM)) cr3 &= ~(X86_CR3_LAM_U48 | X86_CR3_LAM_U57); return kvm_vcpu_is_legal_gpa(vcpu, cr3); diff --git a/arch/x86/kvm/governed_features.h b/arch/x86/kvm/governed_features.h index 423a73395c102..ad463b1ed4e4a 100644 --- a/arch/x86/kvm/governed_features.h +++ b/arch/x86/kvm/governed_features.h @@ -16,6 +16,7 @@ KVM_GOVERNED_X86_FEATURE(PAUSEFILTER) KVM_GOVERNED_X86_FEATURE(PFTHRESHOLD) KVM_GOVERNED_X86_FEATURE(VGIF) KVM_GOVERNED_X86_FEATURE(VNMI) +KVM_GOVERNED_X86_FEATURE(LAM) #undef KVM_GOVERNED_X86_FEATURE #undef KVM_GOVERNED_FEATURE diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h index 580e2414b88c7..60f21bb4c27b1 100644 --- a/arch/x86/kvm/mmu.h +++ b/arch/x86/kvm/mmu.h @@ -148,8 +148,7 @@ static inline unsigned long kvm_get_active_pcid(struct kvm_vcpu *vcpu) static inline unsigned long kvm_get_active_cr3_lam_bits(struct kvm_vcpu *vcpu) { - if (!kvm_cpu_cap_has(X86_FEATURE_LAM) || - !guest_cpuid_has(vcpu, X86_FEATURE_LAM)) + if (!guest_can_use(vcpu, X86_FEATURE_LAM)) return 0; return kvm_read_cr3(vcpu) & (X86_CR3_LAM_U48 | X86_CR3_LAM_U57); diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 3825ab316be9f..d30df9b3fe3e5 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -7763,6 +7763,7 @@ static void vmx_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu) kvm_governed_feature_check_and_set(vcpu, X86_FEATURE_XSAVES); kvm_governed_feature_check_and_set(vcpu, X86_FEATURE_VMX); + kvm_governed_feature_check_and_set(vcpu, X86_FEATURE_LAM); vmx_setup_uret_msrs(vmx);