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authorHaozhong Zhang <haozhong.zhang@intel.com>2017-07-04 10:27:41 +0800
committerPaolo Bonzini <pbonzini@redhat.com>2017-07-04 11:30:52 +0200
commit691bd4340bef49cf7e5855d06cf24444b5bf2d85 (patch)
tree3bf7758961af0effa9ba9e13d92e2e62f803a89a
parent995f00a619584e65e53eff372d9b73b121a7bad5 (diff)
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kvm: vmx: allow host to access guest MSR_IA32_BNDCFGS
It's easier for host applications, such as QEMU, if they can always access guest MSR_IA32_BNDCFGS in VMCS, even though MPX is disabled in guest cpuid. Cc: stable@vger.kernel.org Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
-rw-r--r--arch/x86/kvm/vmx.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index fb0471268a14..b4cfdcfdc1c1 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -3196,7 +3196,8 @@ 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() || !guest_cpuid_has_mpx(vcpu))
+ if (!kvm_mpx_supported() ||
+ (!msr_info->host_initiated && !guest_cpuid_has_mpx(vcpu)))
return 1;
msr_info->data = vmcs_read64(GUEST_BNDCFGS);
break;
@@ -3278,7 +3279,8 @@ 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() || !guest_cpuid_has_mpx(vcpu))
+ if (!kvm_mpx_supported() ||
+ (!msr_info->host_initiated && !guest_cpuid_has_mpx(vcpu)))
return 1;
if (is_noncanonical_address(data & PAGE_MASK) ||
(data & MSR_IA32_BNDCFGS_RSVD))