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authorHaozhong Zhang <haozhong.zhang@intel.com>2017-07-04 10:27:41 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-07-21 07:45:00 +0200
commit3ed43caedf69a6fd417bdda174eb8fa06b3b5dab (patch)
tree937e369116c4a28eebc10f013e3e910c1b10844c
parent6ffa92ffaed817cea7625ebf9c7f217e293923be (diff)
kvm: vmx: allow host to access guest MSR_IA32_BNDCFGS
commit 691bd4340bef49cf7e5855d06cf24444b5bf2d85 upstream. 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. Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-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 a2dd5a5ee472..b12391119ce8 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2812,7 +2812,8 @@ 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;
@@ -2889,7 +2890,8 @@ 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))