summaryrefslogtreecommitdiff
path: root/arch
diff options
context:
space:
mode:
authorJim Mattson <jmattson@google.com>2017-05-24 10:49:25 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-07-21 07:42:24 +0200
commitfab777e70ca46898422f6b62de08f20d86952ed2 (patch)
tree60c7f67fbbca236418efc57685271594b4f6eaa4 /arch
parentbf7c2153561772f58b64b702babc733216be5193 (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>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kvm/cpuid.h8
-rw-r--r--arch/x86/kvm/vmx.c4
2 files changed, 10 insertions, 2 deletions
diff --git a/arch/x86/kvm/cpuid.h b/arch/x86/kvm/cpuid.h
index 35058c2c0eea..9368fecca3ee 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 04d8bde91ca0..e64cde7553c8 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2987,7 +2987,7 @@ 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;
@@ -3069,7 +3069,7 @@ 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;