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>
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;
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;
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;