On 05/29/2018 09:11 AM, Jim Mattson wrote:
Disallow changes to the VMX capability MSRs while the vCPU is in VMX
operation. Although this does break the existing API, it helps to
avoid some potentially tricky situations for which there is no
architected behavior.
Signed-off-by: Jim Mattson <jmattson@xxxxxxxxxx>
---
arch/x86/kvm/vmx.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index e50beb76d846..5ea57442fef9 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -3538,6 +3538,13 @@ static int vmx_set_vmx_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 data)
{
struct vcpu_vmx *vmx = to_vmx(vcpu);
+ /*
+ * Don't allow changes to the VMX capability MSRs while the vCPU
+ * is in VMX operation.
+ */
+ if (vmx->nested.vmxon)
+ return -EBUSY;
+
switch (msr_index) {
case MSR_IA32_VMX_BASIC:
return vmx_restore_vmx_basic(vmx, data);
This check can be placed right in vmx_set_msr():
if (!nested_vmx_allowed(vcpu) ||
(vmx->nested.vmxon))
return 1;
Other than that,
Reviewed-by: Krish Sadhukhan <krish.sadhukhan@xxxxxxxxxx>
