Index: head/sys/dev/hyperv/vmbus/hv_et.c
===================================================================
--- head/sys/dev/hyperv/vmbus/hv_et.c
+++ head/sys/dev/hyperv/vmbus/hv_et.c
@@ -113,6 +113,9 @@
 static int
 vmbus_et_probe(device_t dev)
 {
+	if (resource_disabled(VMBUS_ET_NAME, 0))
+		return (ENXIO);
+
 	device_set_desc(dev, "Hyper-V event timer");
 
 	return (BUS_PROBE_NOWILDCARD);