commit 4439af9f911ae0243ffe4e2dfc12bace49605d8b
author Jim Mattson <jmattson@google.com> Wed May 24 10:49:25 2017 -0700
committer Radim Krčmář <rkrcmar@redhat.com> Wed Jun 07 16:28:15 2017 +0200
tree 3062d9fd5f53b990277c43c01f06af6f0dafbbf0
parent a8b6fda38f80e75afa3b125c9e7f2550b579454b

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: 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>

arch/x86/kvm/vmx.c

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 577bb1d..a339e97 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;