[PATCH 3/3] KVM: nVMX: check for null vmcs12 when L1 does invept

[Bandan Das <bsd@redhat.com>]

Some L1 hypervisors such as Xen seem to be calling invept after
vmclear or before vmptrld on L2. In this case, proceed with
falling through and syncing roots as a case where
context wide invalidation can't be supported

Signed-off-by: Bandan Das <bsd@redhat.com>
---
 arch/x86/kvm/vmx.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index c707389..b407b3a 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -6435,8 +6435,9 @@ static int handle_invept(struct kvm_vcpu *vcpu)
 
 	switch (type) {
 	case VMX_EPT_EXTENT_CONTEXT:
-		if ((operand.eptp & eptp_mask) !=
-				(nested_ept_get_cr3(vcpu) & eptp_mask))
+		if (get_vmcs12(vcpu) &&
+		    ((operand.eptp & eptp_mask) != (nested_ept_get_cr3(vcpu) &
+						    eptp_mask)))
 			break;
 	case VMX_EPT_EXTENT_GLOBAL:
 		kvm_mmu_sync_roots(vcpu);
-- 
1.8.3.1