| Message ID | 20200302235709.27467-66-sean.j.christopherson@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: x86: Introduce KVM cpu caps | expand |
Sean Christopherson <sean.j.christopherson@intel.com> writes: > Set NRIPS in KVM capabilities if and only if nrips=true, which naturally > incorporates the boot_cpu_has() check, and set nrips_enabled only if the > KVM capability is enabled. > > Note, previously KVM would set nrips_enabled based purely on userspace > input, but at worst that would cause KVM to propagate garbage into L1, > i.e. userspace would simply be hosing its VM. > > Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> > --- > arch/x86/kvm/svm.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c > index 8e39dcd3160d..32d9c13ec6b9 100644 > --- a/arch/x86/kvm/svm.c > +++ b/arch/x86/kvm/svm.c > @@ -1377,7 +1377,7 @@ static __init void svm_set_cpu_caps(void) > if (nested) { > kvm_cpu_cap_set(X86_FEATURE_SVM); > > - if (boot_cpu_has(X86_FEATURE_NRIPS)) > + if (nrips) > kvm_cpu_cap_set(X86_FEATURE_NRIPS); > > if (npt_enabled) > @@ -6031,7 +6031,8 @@ static void svm_cpuid_update(struct kvm_vcpu *vcpu) > boot_cpu_has(X86_FEATURE_XSAVES); > > /* Update nrips enabled cache */ > - svm->nrips_enabled = !!guest_cpuid_has(&svm->vcpu, X86_FEATURE_NRIPS); > + svm->nrips_enabled = kvm_cpu_cap_has(X86_FEATURE_NRIPS) && > + guest_cpuid_has(&svm->vcpu, X86_FEATURE_NRIPS); > > if (!kvm_vcpu_apicv_active(vcpu)) > return; Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 8e39dcd3160d..32d9c13ec6b9 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -1377,7 +1377,7 @@ static __init void svm_set_cpu_caps(void) if (nested) { kvm_cpu_cap_set(X86_FEATURE_SVM); - if (boot_cpu_has(X86_FEATURE_NRIPS)) + if (nrips) kvm_cpu_cap_set(X86_FEATURE_NRIPS); if (npt_enabled) @@ -6031,7 +6031,8 @@ static void svm_cpuid_update(struct kvm_vcpu *vcpu) boot_cpu_has(X86_FEATURE_XSAVES); /* Update nrips enabled cache */ - svm->nrips_enabled = !!guest_cpuid_has(&svm->vcpu, X86_FEATURE_NRIPS); + svm->nrips_enabled = kvm_cpu_cap_has(X86_FEATURE_NRIPS) && + guest_cpuid_has(&svm->vcpu, X86_FEATURE_NRIPS); if (!kvm_vcpu_apicv_active(vcpu)) return;
Set NRIPS in KVM capabilities if and only if nrips=true, which naturally incorporates the boot_cpu_has() check, and set nrips_enabled only if the KVM capability is enabled. Note, previously KVM would set nrips_enabled based purely on userspace input, but at worst that would cause KVM to propagate garbage into L1, i.e. userspace would simply be hosing its VM. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> --- arch/x86/kvm/svm.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)