Index: head/sys/dev/hyperv/include/hyperv.h
===================================================================
--- head/sys/dev/hyperv/include/hyperv.h
+++ head/sys/dev/hyperv/include/hyperv.h
@@ -539,6 +539,7 @@
 
 typedef struct hv_vmbus_channel {
 	struct hv_device*		device;
+	device_t			ch_dev;
 	struct vmbus_softc		*vmbus_sc;
 	hv_vmbus_channel_state		state;
 	uint32_t			ch_flags;	/* VMBUS_CHAN_FLAG_ */
Index: head/sys/dev/hyperv/vmbus/hv_channel_mgmt.c
===================================================================
--- head/sys/dev/hyperv/vmbus/hv_channel_mgmt.c
+++ head/sys/dev/hyperv/vmbus/hv_channel_mgmt.c
@@ -163,6 +163,7 @@
 			 */
 			new_channel->primary_channel = channel;
 			new_channel->device = channel->device;
+			new_channel->ch_dev = channel->ch_dev;
 			mtx_lock(&channel->sc_lock);
 			TAILQ_INSERT_TAIL(&channel->sc_list_anchor,
 			    new_channel, sc_list_entry);
@@ -216,9 +217,12 @@
 	 * Add the new device to the bus. This will kick off device-driver
 	 * binding which eventually invokes the device driver's AddDevice()
 	 * method.
+	 *
+	 * NOTE:
+	 * Error is ignored here; don't have much to do if error really
+	 * happens.
 	 */
-	hv_vmbus_child_device_register(new_channel->vmbus_sc,
-	    new_channel->device);
+	hv_vmbus_child_device_register(new_channel);
 }
 
 void
@@ -365,8 +369,8 @@
 	struct hv_vmbus_channel *chan = xchan;
 
 	if (HV_VMBUS_CHAN_ISPRIMARY(chan)) {
-		/* Only primary channel owns the hv_device */
-		hv_vmbus_child_device_unregister(chan->device);
+		/* Only primary channel owns the device */
+		hv_vmbus_child_device_unregister(chan);
 		/* NOTE: DO NOT free primary channel for now */
 	} else {
 		struct vmbus_softc *sc = chan->vmbus_sc;
@@ -446,8 +450,8 @@
 	    TAILQ_REMOVE(&sc->vmbus_chlist, channel, ch_link);
 
 	    if (HV_VMBUS_CHAN_ISPRIMARY(channel)) {
-		/* Only primary channel owns the hv_device */
-		hv_vmbus_child_device_unregister(channel->device);
+		/* Only primary channel owns the device */
+		hv_vmbus_child_device_unregister(channel);
 	    }
 	    hv_vmbus_free_vmbus_channel(channel);
 	}
Index: head/sys/dev/hyperv/vmbus/hv_vmbus_priv.h
===================================================================
--- head/sys/dev/hyperv/vmbus/hv_vmbus_priv.h
+++ head/sys/dev/hyperv/vmbus/hv_vmbus_priv.h
@@ -215,9 +215,9 @@
 struct hv_device*	hv_vmbus_child_device_create(
 			    struct hv_vmbus_channel *channel);
 
-void			hv_vmbus_child_device_register(struct vmbus_softc *,
-					struct hv_device *child_dev);
+int			hv_vmbus_child_device_register(
+					struct hv_vmbus_channel *chan);
 int			hv_vmbus_child_device_unregister(
-					struct hv_device *child_dev);
+					struct hv_vmbus_channel *chan);
 
 #endif  /* __HYPERV_PRIV_H__ */
Index: head/sys/dev/hyperv/vmbus/vmbus.c
===================================================================
--- head/sys/dev/hyperv/vmbus/vmbus.c
+++ head/sys/dev/hyperv/vmbus/vmbus.c
@@ -989,18 +989,21 @@
 static int
 vmbus_child_pnpinfo_str(device_t dev, device_t child, char *buf, size_t buflen)
 {
-	struct hv_device *dev_ctx = device_get_ivars(child);
+	const struct hv_vmbus_channel *chan;
 	char guidbuf[HYPERV_GUID_STRLEN];
 
-	if (dev_ctx == NULL)
+	if (device_get_ivars(child) == NULL) {
+		/* Event timer device, which does not belong to a channel */
 		return (0);
+	}
+	chan = vmbus_get_channel(child);
 
 	strlcat(buf, "classid=", buflen);
-	hyperv_guid2str(&dev_ctx->class_id, guidbuf, sizeof(guidbuf));
+	hyperv_guid2str(&chan->ch_guid_type, guidbuf, sizeof(guidbuf));
 	strlcat(buf, guidbuf, buflen);
 
 	strlcat(buf, " deviceid=", buflen);
-	hyperv_guid2str(&dev_ctx->device_id, guidbuf, sizeof(guidbuf));
+	hyperv_guid2str(&chan->ch_guid_inst, guidbuf, sizeof(guidbuf));
 	strlcat(buf, guidbuf, buflen);
 
 	return (0);
@@ -1023,40 +1026,48 @@
 	return (child_dev);
 }
 
-void
-hv_vmbus_child_device_register(struct vmbus_softc *sc,
-    struct hv_device *child_dev)
+int
+hv_vmbus_child_device_register(struct hv_vmbus_channel *chan)
 {
-	device_t child, parent;
-
-	parent = sc->vmbus_dev;
-	if (bootverbose) {
-		char name[HYPERV_GUID_STRLEN];
-
-		hyperv_guid2str(&child_dev->class_id, name, sizeof(name));
-		device_printf(parent, "add device, classid: %s\n", name);
+	struct vmbus_softc *sc = chan->vmbus_sc;
+	device_t parent = sc->vmbus_dev;
+	int error = 0;
+
+	chan->ch_dev = device_add_child(parent, NULL, -1);
+	if (chan->ch_dev == NULL) {
+		device_printf(parent, "device_add_child for chan%u failed\n",
+		    chan->ch_id);
+		error = ENXIO;
+		goto done;
 	}
+	chan->device->device = chan->ch_dev;
+	device_set_ivars(chan->ch_dev, chan->device);
 
-	child = device_add_child(parent, NULL, -1);
-	child_dev->device = child;
-	device_set_ivars(child, child_dev);
-
-	/* New device was added to vmbus */
+done:
+	/* New device has been/should be added to vmbus. */
 	vmbus_scan_newdev(sc);
+	return error;
 }
 
 int
-hv_vmbus_child_device_unregister(struct hv_device *child_dev)
+hv_vmbus_child_device_unregister(struct hv_vmbus_channel *chan)
 {
-	int ret = 0;
+	int error;
+
+	if (chan->ch_dev == NULL) {
+		/* Failed to add a device. */
+		return 0;
+	}
+
 	/*
 	 * XXXKYS: Ensure that this is the opposite of
 	 * device_add_child()
 	 */
 	mtx_lock(&Giant);
-	ret = device_delete_child(vmbus_get_device(), child_dev->device);
+	error = device_delete_child(chan->vmbus_sc->vmbus_dev, chan->ch_dev);
 	mtx_unlock(&Giant);
-	return(ret);
+
+	return error;
 }
 
 static int
@@ -1082,9 +1093,9 @@
 static int
 vmbus_probe_guid_method(device_t bus, device_t dev, const struct hv_guid *guid)
 {
-	struct hv_device *hv_dev = device_get_ivars(dev);
+	const struct hv_vmbus_channel *chan = vmbus_get_channel(dev);
 
-	if (memcmp(&hv_dev->class_id, guid, sizeof(struct hv_guid)) == 0)
+	if (memcmp(&chan->ch_guid_type, guid, sizeof(struct hv_guid)) == 0)
 		return 0;
 	return ENXIO;
 }