Commit 4439af9f authored by Jim Mattson's avatar Jim Mattson Committed by Radim Krčmář

kvm: x86: Guest BNDCFGS requires guest MPX support

The BNDCFGS MSR should only be exposed to the guest if the guest
supports MPX. (cf. the TSC_AUX MSR and RDTSCP.)

Fixes: 0dd376e7 ("KVM: x86: add MSR_IA32_BNDCFGS to msrs_to_save")
Change-Id: I3ad7c01bda616715137ceac878f3fa7e66b6b387
Signed-off-by: default avatarJim Mattson <jmattson@google.com>
Signed-off-by: default avatarRadim Krčmář <rkrcmar@redhat.com>
parent a8b6fda3
...@@ -144,6 +144,14 @@ static inline bool guest_cpuid_has_rtm(struct kvm_vcpu *vcpu) ...@@ -144,6 +144,14 @@ static inline bool guest_cpuid_has_rtm(struct kvm_vcpu *vcpu)
return best && (best->ebx & bit(X86_FEATURE_RTM)); 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) static inline bool guest_cpuid_has_rdtscp(struct kvm_vcpu *vcpu)
{ {
struct kvm_cpuid_entry2 *best; struct kvm_cpuid_entry2 *best;
......
...@@ -3195,7 +3195,7 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) ...@@ -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); msr_info->data = vmcs_readl(GUEST_SYSENTER_ESP);
break; break;
case MSR_IA32_BNDCFGS: case MSR_IA32_BNDCFGS:
if (!kvm_mpx_supported()) if (!kvm_mpx_supported() || !guest_cpuid_has_mpx(vcpu))
return 1; return 1;
msr_info->data = vmcs_read64(GUEST_BNDCFGS); msr_info->data = vmcs_read64(GUEST_BNDCFGS);
break; break;
...@@ -3277,7 +3277,7 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) ...@@ -3277,7 +3277,7 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
vmcs_writel(GUEST_SYSENTER_ESP, data); vmcs_writel(GUEST_SYSENTER_ESP, data);
break; break;
case MSR_IA32_BNDCFGS: case MSR_IA32_BNDCFGS:
if (!kvm_mpx_supported()) if (!kvm_mpx_supported() || !guest_cpuid_has_mpx(vcpu))
return 1; return 1;
vmcs_write64(GUEST_BNDCFGS, data); vmcs_write64(GUEST_BNDCFGS, data);
break; break;
......
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