KVM: nVMX: Fail VMLAUNCH and VMRESUME on shadow VMCS
Signed-off-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 44e2b82..f6ec898 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -11876,6 +11876,17 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch)
vmcs12 = get_vmcs12(vcpu);
+ /*
+ * Can't VMLAUNCH or VMRESUME a shadow VMCS. Despite the fact
+ * that there *is* a valid VMCS pointer, RFLAGS.CF is set
+ * rather than RFLAGS.ZF, and no error number is stored to the
+ * VM-instruction error field.
+ */
+ if (vmcs12->hdr.shadow_vmcs) {
+ nested_vmx_failInvalid(vcpu);
+ goto out;
+ }
+
if (enable_shadow_vmcs)
copy_shadow_to_vmcs12(vmx);