diff options
| author |   Sean Christopherson <sean.j.christopherson@intel.com> | 2019-12-10 14:44:15 -0800 |
|---|---|---|
| committer |   Paolo Bonzini <pbonzini@redhat.com> | 2020-01-21 13:58:10 +0100 |
| commit | 96be4e069c938e4a5fc7125de7e1cc7089b1adef (patch) | |
| tree | 954b6bced81f4878ee3412394684286b0361006e | |
| parent | KVM: x86: Ensure all logical CPUs have consistent reserved cr4 bits (diff) | |
| download | linux-dev-96be4e069c938e4a5fc7125de7e1cc7089b1adef.tar.xz linux-dev-96be4e069c938e4a5fc7125de7e1cc7089b1adef.zip | |
KVM: x86: Drop special XSAVE handling from guest_cpuid_has()
Now that KVM prevents setting host-reserved CR4 bits, drop the dedicated
XSAVE check in guest_cpuid_has() in favor of open coding similar checks
in the SVM/VMX XSAVES enabling flows.
Note, checking boot_cpu_has(X86_FEATURE_XSAVE) in the XSAVES flows is
technically redundant with respect to the CR4 reserved bit checks, e.g.
XSAVES #UDs if CR4.OSXSAVE=0 and arch.xsaves_enabled is consumed if and
only if CR4.OXSAVE=1 in guest. Keep (add?) the explicit boot_cpu_has()
checks to help document KVM's usage of arch.xsaves_enabled.
No functional change intended.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | arch/x86/kvm/cpuid.h | 4 | ||||
| -rw-r--r-- | arch/x86/kvm/svm.c | 1 | ||||
| -rw-r--r-- | arch/x86/kvm/vmx/vmx.c | 1 |
3 files changed, 2 insertions, 4 deletions
diff --git a/arch/x86/kvm/cpuid.h b/arch/x86/kvm/cpuid.h index d78a61408243..b82ae4d3dc71 100644 --- a/arch/x86/kvm/cpuid.h +++ b/arch/x86/kvm/cpuid.h @@ -93,10 +93,6 @@ static __always_inline bool guest_cpuid_has(struct kvm_vcpu *vcpu, unsigned x86_ { int *reg; - if (x86_feature == X86_FEATURE_XSAVE && - !static_cpu_has(X86_FEATURE_XSAVE)) - return false; - reg = guest_cpuid_get_register(vcpu, x86_feature); if (!reg) return false; diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 9583ae7ae218..d399eb7bbff3 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -5917,6 +5917,7 @@ static void svm_cpuid_update(struct kvm_vcpu *vcpu) struct vcpu_svm *svm = to_svm(vcpu); vcpu->arch.xsaves_enabled = guest_cpuid_has(vcpu, X86_FEATURE_XSAVE) && + boot_cpu_has(X86_FEATURE_XSAVE) && boot_cpu_has(X86_FEATURE_XSAVES); /* Update nrips enabled cache */ diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 857dd0898e5f..3e732d092c40 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -4049,6 +4049,7 @@ static void vmx_compute_secondary_exec_control(struct vcpu_vmx *vmx) if (vmx_xsaves_supported()) { /* Exposing XSAVES only when XSAVE is exposed */ bool xsaves_enabled = + boot_cpu_has(X86_FEATURE_XSAVE) && guest_cpuid_has(vcpu, X86_FEATURE_XSAVE) && guest_cpuid_has(vcpu, X86_FEATURE_XSAVES); |