KVM: nVMX: do not leak PML full vmexit to L1

commit ab007cc9 upstream.

The PML feature is not exposed to guests so we should not be forwarding
the vmexit either.

This commit fixes BSOD 0x20001 (HYPERVISOR_ERROR) when running Hyper-V
enabled Windows Server 2016 in L1 on hardware that supports PML.

Fixes: 843e4330 ("KVM: VMX: Add PML support in VMX")
Signed-off-by: Ladi Prosek <lprosek@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

arch/x86/kvm/vmx.c

@@ -7838,6 +7838,9 @@ static bool nested_vmx_exit_handled(struct kvm_vcpu *vcpu)
 		return nested_cpu_has2(vmcs12, SECONDARY_EXEC_XSAVES);
 	case EXIT_REASON_PCOMMIT:
 		return nested_cpu_has2(vmcs12, SECONDARY_EXEC_PCOMMIT);
+	case EXIT_REASON_PML_FULL:
+		/* We don't expose PML support to L1. */
+		return false;
 	default:
 		return true;
 	}