KVM: SVM: Check for nested vmrun intercept before emulating vmrun

This patch lets the nested vmrun fail if the L1 hypervisor
has not intercepted vmrun. This fixes the "vmrun intercept
check" unit test.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 116e034..a0e5c7e 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -2014,6 +2014,14 @@
 	return true;
 }
 
+static bool nested_vmcb_checks(struct vmcb *vmcb)
+{
+	if ((vmcb->control.intercept & (1ULL << INTERCEPT_VMRUN)) == 0)
+		return false;
+
+	return true;
+}
+
 static bool nested_svm_vmrun(struct vcpu_svm *svm)
 {
 	struct vmcb *nested_vmcb;
@@ -2028,6 +2036,17 @@
 	if (!nested_vmcb)
 		return false;
 
+	if (!nested_vmcb_checks(nested_vmcb)) {
+		nested_vmcb->control.exit_code    = SVM_EXIT_ERR;
+		nested_vmcb->control.exit_code_hi = 0;
+		nested_vmcb->control.exit_info_1  = 0;
+		nested_vmcb->control.exit_info_2  = 0;
+
+		nested_svm_unmap(page);
+
+		return false;
+	}
+
 	trace_kvm_nested_vmrun(svm->vmcb->save.rip - 3, vmcb_gpa,
 			       nested_vmcb->save.rip,
 			       nested_vmcb->control.int_ctl,