Index: head/sys/dev/hyperv/include/vmbus.h
===================================================================
--- head/sys/dev/hyperv/include/vmbus.h
+++ head/sys/dev/hyperv/include/vmbus.h
@@ -117,6 +117,7 @@
 
 struct vmbus_channel;
 struct hyperv_guid;
+struct task;
 
 typedef void	(*vmbus_chan_callback_t)(struct vmbus_channel *, void *);
 
@@ -134,6 +135,8 @@
 		    int udlen, vmbus_chan_callback_t cb, void *cbarg);
 void		vmbus_chan_close(struct vmbus_channel *chan);
 void		vmbus_chan_intr_drain(struct vmbus_channel *chan);
+void		vmbus_chan_run_task(struct vmbus_channel *chan,
+		    struct task *task);
 
 int		vmbus_chan_gpadl_connect(struct vmbus_channel *chan,
 		    bus_addr_t paddr, int size, uint32_t *gpadl);
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
@@ -1713,3 +1713,11 @@
 
 	return (vmbus_rxbr_empty(&chan->ch_rxbr));
 }
+
+void
+vmbus_chan_run_task(struct vmbus_channel *chan, struct task *task)
+{
+
+	taskqueue_enqueue(chan->ch_tq, task);
+	taskqueue_drain(chan->ch_tq, task);
+}