diff options
| author | Jim Mattson <jmattson@google.com> | 2017-05-24 10:49:25 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-07-21 06:59:13 +0200 |
| commit | 2fcf9884f004cf3c994ab112b473fe520689cfd3 (patch) | |
| tree | 879712782681fc6266922272a90c55407893d05a | |
| parent | 09ae0c8639447300c5875edf5a304dd829650897 (diff) | |
kvm: x86: Guest BNDCFGS requires guest MPX support
commit 4439af9f911ae0243ffe4e2dfc12bace49605d8b upstream.
The BNDCFGS MSR should only be exposed to the guest if the guest
supports MPX. (cf. the TSC_AUX MSR and RDTSCP.)
Fixes: 0dd376e709975779 ("KVM: x86: add MSR_IA32_BNDCFGS to msrs_to_save")
Change-Id: I3ad7c01bda616715137ceac878f3fa7e66b6b387
Signed-off-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/x86/kvm/cpuid.h | 8 | ||||
| -rw-r--r-- | arch/x86/kvm/vmx.c | 4 |
2 files changed, 10 insertions, 2 deletions
diff --git a/arch/x86/kvm/cpuid.h b/arch/x86/kvm/cpuid.h index a6fd40aade7c..da6728383052 100644 --- a/arch/x86/kvm/cpuid.h +++ b/arch/x86/kvm/cpuid.h @@ -144,6 +144,14 @@ static inline bool guest_cpuid_has_rtm(struct kvm_vcpu *vcpu) return best && (best->ebx & bit(X86_FEATURE_RTM)); } +static inline bool guest_cpuid_has_mpx(struct kvm_vcpu *vcpu) +{ + struct kvm_cpuid_entry2 *best; + + best = kvm_find_cpuid_entry(vcpu, 7, 0); + return best && (best->ebx & bit(X86_FEATURE_MPX)); +} + static inline bool guest_cpuid_has_rdtscp(struct kvm_vcpu *vcpu) { struct kvm_cpuid_entry2 *best; diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 8e14d2f31b1d..e37ee1b2c05f 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -3195,7 +3195,7 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) msr_info->data = vmcs_readl(GUEST_SYSENTER_ESP); break; case MSR_IA32_BNDCFGS: - if (!kvm_mpx_supported()) + if (!kvm_mpx_supported() || !guest_cpuid_has_mpx(vcpu)) return 1; msr_info->data = vmcs_read64(GUEST_BNDCFGS); break; @@ -3277,7 +3277,7 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) vmcs_writel(GUEST_SYSENTER_ESP, data); break; case MSR_IA32_BNDCFGS: - if (!kvm_mpx_supported()) + if (!kvm_mpx_supported() || !guest_cpuid_has_mpx(vcpu)) return 1; vmcs_write64(GUEST_BNDCFGS, data); break; |