Index: head/sys/dev/hyperv/include/hyperv.h
===================================================================
--- head/sys/dev/hyperv/include/hyperv.h
+++ head/sys/dev/hyperv/include/hyperv.h
@@ -632,6 +632,9 @@
 	TAILQ_ENTRY(hv_vmbus_channel)	ch_link;
 	uint32_t			ch_subidx;	/* subchan index */
 
+	struct hv_guid			ch_guid_type;
+	struct hv_guid			ch_guid_inst;
+
 	struct sysctl_ctx_list		ch_sysctl_ctx;
 } hv_vmbus_channel;
 
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
@@ -127,11 +127,9 @@
 	}
 
 	TAILQ_FOREACH(channel, &sc->vmbus_chlist, ch_link) {
-		if (memcmp(&channel->offer_msg.offer.interface_type,
-		    &new_channel->offer_msg.offer.interface_type,
+		if (memcmp(&channel->ch_guid_type, &new_channel->ch_guid_type,
 		    sizeof(hv_guid)) == 0 &&
-		    memcmp(&channel->offer_msg.offer.interface_instance,
-		    &new_channel->offer_msg.offer.interface_instance,
+		    memcmp(&channel->ch_guid_inst, &new_channel->ch_guid_inst,
 		    sizeof(hv_guid)) == 0)
 			break;
 	}
@@ -212,9 +210,7 @@
 	 * (We need to set the device field before calling
 	 * hv_vmbus_child_device_add())
 	 */
-	new_channel->device = hv_vmbus_child_device_create(
-	    new_channel->offer_msg.offer.interface_type,
-	    new_channel->offer_msg.offer.interface_instance, new_channel);
+	new_channel->device = hv_vmbus_child_device_create(new_channel);
 
 	/*
 	 * Add the new device to the bus. This will kick off device-driver
@@ -296,6 +292,8 @@
 	new_channel->ch_subidx = offer->offer.sub_channel_index;
 	if (offer->monitor_allocated)
 		new_channel->ch_flags |= VMBUS_CHAN_FLAG_HASMNF;
+	new_channel->ch_guid_type = offer->offer.interface_type;
+	new_channel->ch_guid_inst = offer->offer.interface_instance;
 
 	/*
 	 * By default we setup state to enable batched
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
@@ -213,9 +213,7 @@
 			    struct vmbus_softc *);
 
 struct hv_device*	hv_vmbus_child_device_create(
-				hv_guid			device_type,
-				hv_guid			device_instance,
-				hv_vmbus_channel	*channel);
+			    struct hv_vmbus_channel *channel);
 
 void			hv_vmbus_child_device_register(struct vmbus_softc *,
 					struct hv_device *child_dev);
Index: head/sys/dev/hyperv/vmbus/vmbus.c
===================================================================
--- head/sys/dev/hyperv/vmbus/vmbus.c
+++ head/sys/dev/hyperv/vmbus/vmbus.c
@@ -1017,8 +1017,7 @@
 }
 
 struct hv_device *
-hv_vmbus_child_device_create(hv_guid type, hv_guid instance,
-    hv_vmbus_channel *channel)
+hv_vmbus_child_device_create(struct hv_vmbus_channel *channel)
 {
 	hv_device *child_dev;
 
@@ -1028,8 +1027,8 @@
 	child_dev = malloc(sizeof(hv_device), M_DEVBUF, M_WAITOK | M_ZERO);
 
 	child_dev->channel = channel;
-	memcpy(&child_dev->class_id, &type, sizeof(hv_guid));
-	memcpy(&child_dev->device_id, &instance, sizeof(hv_guid));
+	child_dev->class_id = channel->ch_guid_type;
+	child_dev->device_id = channel->ch_guid_inst;
 
 	return (child_dev);
 }