Index: head/sys/dev/hyperv/include/hyperv.h
===================================================================
--- head/sys/dev/hyperv/include/hyperv.h
+++ head/sys/dev/hyperv/include/hyperv.h
@@ -113,7 +113,9 @@
 	uint32_t		ring_data_size;	/* ring_size */
 } hv_vmbus_ring_buffer_info;
 
-typedef void	(*vmbus_chan_callback_t)(void *);
+struct hv_vmbus_channel;
+
+typedef void	(*vmbus_chan_callback_t)(struct hv_vmbus_channel *, void *);
 
 typedef struct hv_vmbus_channel {
 	device_t			ch_dev;
Index: head/sys/dev/hyperv/netvsc/hv_net_vsc.c
===================================================================
--- head/sys/dev/hyperv/netvsc/hv_net_vsc.c
+++ head/sys/dev/hyperv/netvsc/hv_net_vsc.c
@@ -57,7 +57,7 @@
 /*
  * Forward declarations
  */
-static void hv_nv_on_channel_callback(void *xchan);
+static void hv_nv_on_channel_callback(struct hv_vmbus_channel *chan, void *arg);
 static int  hv_nv_init_send_buffer_with_net_vsp(struct hn_softc *sc);
 static int  hv_nv_init_rx_buffer_with_net_vsp(struct hn_softc *);
 static int  hv_nv_destroy_send_buffer(netvsc_dev *net_dev);
@@ -647,7 +647,7 @@
 	chan->ch_dev_rdbuf = malloc(NETVSC_PACKET_SIZE, M_NETVSC, M_WAITOK);
 	vmbus_chan_open(chan, NETVSC_DEVICE_RING_BUFFER_SIZE,
 	    NETVSC_DEVICE_RING_BUFFER_SIZE, NULL, 0,
-	    hv_nv_on_channel_callback, chan);
+	    hv_nv_on_channel_callback, NULL);
 }
 
 /*
@@ -677,7 +677,7 @@
 	 */
 	ret = vmbus_chan_open(chan,
 	    NETVSC_DEVICE_RING_BUFFER_SIZE, NETVSC_DEVICE_RING_BUFFER_SIZE,
-	    NULL, 0, hv_nv_on_channel_callback, chan);
+	    NULL, 0, hv_nv_on_channel_callback, NULL);
 	if (ret != 0) {
 		free(chan->ch_dev_rdbuf, M_NETVSC);
 		goto cleanup;
@@ -973,9 +973,8 @@
  * Net VSC on channel callback
  */
 static void
-hv_nv_on_channel_callback(void *xchan)
+hv_nv_on_channel_callback(struct hv_vmbus_channel *chan, void *arg __unused)
 {
-	struct hv_vmbus_channel *chan = xchan;
 	device_t dev = chan->ch_dev;
 	struct hn_softc *sc = device_get_softc(dev);
 	netvsc_dev *net_dev;
Index: head/sys/dev/hyperv/storvsc/hv_storvsc_drv_freebsd.c
===================================================================
--- head/sys/dev/hyperv/storvsc/hv_storvsc_drv_freebsd.c
+++ head/sys/dev/hyperv/storvsc/hv_storvsc_drv_freebsd.c
@@ -274,7 +274,7 @@
 static void storvsc_free_request(struct storvsc_softc *sc, struct hv_storvsc_request *reqp);
 static enum hv_storage_type storvsc_get_storage_type(device_t dev);
 static void hv_storvsc_rescan_target(struct storvsc_softc *sc);
-static void hv_storvsc_on_channel_callback(void *xchan);
+static void hv_storvsc_on_channel_callback(struct hv_vmbus_channel *chan, void *xsc);
 static void hv_storvsc_on_iocompletion( struct storvsc_softc *sc,
 					struct vstor_packet *vstor_packet,
 					struct hv_storvsc_request *request);
@@ -316,15 +316,13 @@
 
 	memset(&props, 0, sizeof(props));
 
-	new_channel->ch_dev_priv1 = sc;
 	vmbus_chan_cpu_rr(new_channel);
 	ret = vmbus_chan_open(new_channel,
 	    sc->hs_drv_props->drv_ringbuffer_size,
   	    sc->hs_drv_props->drv_ringbuffer_size,
 	    (void *)&props,
 	    sizeof(struct vmstor_chan_props),
-	    hv_storvsc_on_channel_callback,
-	    new_channel);
+	    hv_storvsc_on_channel_callback, sc);
 }
 
 /**
@@ -575,7 +573,6 @@
 	/*
 	 * Open the channel
 	 */
-	KASSERT(sc->hs_chan->ch_dev_priv1 == sc, ("invalid chan priv1"));
 	vmbus_chan_cpu_rr(sc->hs_chan);
 	ret = vmbus_chan_open(
 		sc->hs_chan,
@@ -583,8 +580,7 @@
 		sc->hs_drv_props->drv_ringbuffer_size,
 		(void *)&props,
 		sizeof(struct vmstor_chan_props),
-		hv_storvsc_on_channel_callback,
-		sc->hs_chan);
+		hv_storvsc_on_channel_callback, sc);
 
 	if (ret != 0) {
 		return ret;
@@ -769,11 +765,10 @@
 }
 
 static void
-hv_storvsc_on_channel_callback(void *xchan)
+hv_storvsc_on_channel_callback(struct hv_vmbus_channel *channel, void *xsc)
 {
 	int ret = 0;
-	hv_vmbus_channel *channel = xchan;
-	struct storvsc_softc *sc = channel->ch_dev_priv1;
+	struct storvsc_softc *sc = xsc;
 	uint32_t bytes_recvd;
 	uint64_t request_id;
 	uint8_t packet[roundup2(sizeof(struct vstor_packet), 8)];
@@ -915,7 +910,6 @@
 
 	sc = device_get_softc(dev);
 	sc->hs_chan = vmbus_get_channel(dev);
-	sc->hs_chan->ch_dev_priv1 = sc;
 
 	stor_type = storvsc_get_storage_type(dev);
 
@@ -1265,7 +1259,7 @@
 
 	mtx_assert(&sc->hs_lock, MA_OWNED);
 	mtx_unlock(&sc->hs_lock);
-	hv_storvsc_on_channel_callback(sc->hs_chan);
+	hv_storvsc_on_channel_callback(sc->hs_chan, sc);
 	mtx_lock(&sc->hs_lock);
 }
 
Index: head/sys/dev/hyperv/utilities/hv_heartbeat.c
===================================================================
--- head/sys/dev/hyperv/utilities/hv_heartbeat.c
+++ head/sys/dev/hyperv/utilities/hv_heartbeat.c
@@ -49,10 +49,9 @@
  * Process heartbeat message
  */
 static void
-hv_heartbeat_cb(void *context)
+hv_heartbeat_cb(struct hv_vmbus_channel *channel, void *context)
 {
 	uint8_t*		buf;
-	hv_vmbus_channel*	channel;
 	int			recvlen;
 	uint64_t		requestid;
 	int			ret;
@@ -63,7 +62,6 @@
 
 	softc = (hv_util_sc*)context;
 	buf = softc->receive_buffer;
-	channel = softc->channel;
 
 	recvlen = PAGE_SIZE;
 	ret = vmbus_chan_recv(channel, buf, &recvlen, &requestid);
Index: head/sys/dev/hyperv/utilities/hv_kvp.c
===================================================================
--- head/sys/dev/hyperv/utilities/hv_kvp.c
+++ head/sys/dev/hyperv/utilities/hv_kvp.c
@@ -121,6 +121,7 @@
  */
 typedef struct hv_kvp_sc {
 	struct hv_util_sc	util_sc;
+	device_t		dev;
 
 	/* Unless specified the pending mutex should be
 	 * used to alter the values of the following parameters:
@@ -576,7 +577,7 @@
 	hv_icmsg_hdrp->status = error;
 	hv_icmsg_hdrp->icflags = HV_ICMSGHDRFLAG_TRANSACTION | HV_ICMSGHDRFLAG_RESPONSE;
 
-	error = vmbus_chan_send(sc->util_sc.channel,
+	error = vmbus_chan_send(vmbus_get_channel(sc->dev),
 	    VMBUS_CHANPKT_TYPE_INBAND, 0, sc->rcv_buf, sc->host_msg_len,
 	    sc->host_msg_id);
 	if (error)
@@ -625,7 +626,7 @@
 
 	sc = (hv_kvp_sc*)context;
 	kvp_buf = sc->util_sc.receive_buffer;
-	channel = sc->util_sc.channel;
+	channel = vmbus_get_channel(sc->dev);
 
 	recvlen = 2 * PAGE_SIZE;
 	ret = vmbus_chan_recv(channel, kvp_buf, &recvlen, &requestid);
@@ -709,7 +710,7 @@
  * Callback routine that gets called whenever there is a message from host
  */
 static void
-hv_kvp_callback(void *context)
+hv_kvp_callback(struct hv_vmbus_channel *chan __unused, void *context)
 {
 	hv_kvp_sc *sc = (hv_kvp_sc*)context;
 	/*
@@ -813,7 +814,7 @@
 	if (sc->register_done == false) {
 		if (sc->daemon_kvp_msg.kvp_hdr.operation == HV_KVP_OP_REGISTER) {
 			sc->register_done = true;
-			hv_kvp_callback(dev->si_drv1);
+			hv_kvp_callback(vmbus_get_channel(sc->dev), dev->si_drv1);
 		}
 		else {
 			hv_kvp_log_info("%s, KVP Registration Failed\n", __func__);
@@ -891,6 +892,7 @@
 	hv_kvp_sc *sc = (hv_kvp_sc*)device_get_softc(dev);
 
 	sc->util_sc.callback = hv_kvp_callback;
+	sc->dev = dev;
 	sema_init(&sc->dev_sema, 0, "hv_kvp device semaphore");
 	mtx_init(&sc->pending_mutex, "hv-kvp pending mutex",
 		NULL, MTX_DEF);
Index: head/sys/dev/hyperv/utilities/hv_shutdown.c
===================================================================
--- head/sys/dev/hyperv/utilities/hv_shutdown.c
+++ head/sys/dev/hyperv/utilities/hv_shutdown.c
@@ -53,10 +53,9 @@
  * Shutdown
  */
 static void
-hv_shutdown_cb(void *context)
+hv_shutdown_cb(struct hv_vmbus_channel *channel, void *context)
 {
 	uint8_t*			buf;
-	hv_vmbus_channel*		channel;
 	uint8_t				execute_shutdown = 0;
 	hv_vmbus_icmsg_hdr*		icmsghdrp;
 	uint32_t			recv_len;
@@ -67,7 +66,6 @@
 
 	softc = (hv_util_sc*)context;
 	buf = softc->receive_buffer;
-	channel = softc->channel;
 
 	recv_len = PAGE_SIZE;
 	ret = vmbus_chan_recv(channel, buf, &recv_len, &request_id);
Index: head/sys/dev/hyperv/utilities/hv_timesync.c
===================================================================
--- head/sys/dev/hyperv/utilities/hv_timesync.c
+++ head/sys/dev/hyperv/utilities/hv_timesync.c
@@ -130,9 +130,8 @@
  * Time Sync Channel message handler
  */
 static void
-hv_timesync_cb(void *context)
+hv_timesync_cb(struct hv_vmbus_channel *channel, void *context)
 {
-	hv_vmbus_channel*	channel;
 	hv_vmbus_icmsg_hdr*	icmsghdrp;
 	uint32_t		recvlen;
 	uint64_t		requestId;
@@ -142,7 +141,6 @@
 	hv_timesync_sc		*softc;
 
 	softc = (hv_timesync_sc*)context;
-	channel = softc->util_sc.channel;
 	time_buf = softc->util_sc.receive_buffer;
 
 	recvlen = PAGE_SIZE;
Index: head/sys/dev/hyperv/utilities/hv_util.h
===================================================================
--- head/sys/dev/hyperv/utilities/hv_util.h
+++ head/sys/dev/hyperv/utilities/hv_util.h
@@ -39,9 +39,7 @@
 	/*
 	 * function to process Hyper-V messages
 	 */
-	void (*callback)(void *);
-
-	struct hv_vmbus_channel	*channel;
+	void (*callback)(struct hv_vmbus_channel *, void *);
 	uint8_t			*receive_buffer;
 } hv_util_sc;
 
Index: head/sys/dev/hyperv/utilities/hv_util.c
===================================================================
--- head/sys/dev/hyperv/utilities/hv_util.c
+++ head/sys/dev/hyperv/utilities/hv_util.c
@@ -77,12 +77,13 @@
 hv_util_attach(device_t dev)
 {
 	struct hv_util_sc*	softc;
+	struct hv_vmbus_channel *chan;
 	int			ret;
 
 	softc = device_get_softc(dev);
-	softc->channel = vmbus_get_channel(dev);
 	softc->receive_buffer =
 		malloc(4 * PAGE_SIZE, M_DEVBUF, M_WAITOK | M_ZERO);
+	chan = vmbus_get_channel(dev);
 
 	/*
 	 * These services are not performance critical and do not need
@@ -91,11 +92,10 @@
 	 * Turn off batched reading for all util drivers before we open the
 	 * channel.
 	 */
-	vmbus_chan_set_readbatch(softc->channel, false);
+	vmbus_chan_set_readbatch(chan, false);
 
-	ret = vmbus_chan_open(softc->channel, 4 * PAGE_SIZE,
-			4 * PAGE_SIZE, NULL, 0,
-			softc->callback, softc);
+	ret = vmbus_chan_open(chan, 4 * PAGE_SIZE, 4 * PAGE_SIZE, NULL, 0,
+	    softc->callback, softc);
 
 	if (ret)
 		goto error0;
@@ -112,7 +112,7 @@
 {
 	struct hv_util_sc *sc = device_get_softc(dev);
 
-	vmbus_chan_close(sc->channel);
+	vmbus_chan_close(vmbus_get_channel(dev));
 	free(sc->receive_buffer, M_DEVBUF);
 
 	return (0);
Index: head/sys/dev/hyperv/vmbus/vmbus_chan.c
===================================================================
--- head/sys/dev/hyperv/vmbus/vmbus_chan.c
+++ head/sys/dev/hyperv/vmbus/vmbus_chan.c
@@ -801,7 +801,7 @@
 	for (;;) {
 		uint32_t left;
 
-		cb(cbarg);
+		cb(chan, cbarg);
 
 		left = hv_ring_buffer_read_end(&chan->ch_rxbr);
 		if (left == 0) {
@@ -817,7 +817,7 @@
 {
 	struct hv_vmbus_channel *chan = xchan;
 
-	chan->ch_cb(chan->ch_cbarg);
+	chan->ch_cb(chan, chan->ch_cbarg);
 }
 
 static __inline void