3 files changed, 30 insertions, 0 deletions

diff --git a/sys/dev/hyperv/include/vmbus.h b/sys/dev/hyperv/include/vmbus.h
index 090f9b1fcd93..50f3148d35d7 100644
--- a/sys/dev/hyperv/include/vmbus.h
+++ b/sys/dev/hyperv/include/vmbus.h
@@ -173,5 +173,7 @@ const struct hyperv_guid *
 		vmbus_chan_guid_inst(const struct vmbus_channel *chan);
 int		vmbus_chan_prplist_nelem(int br_size, int prpcnt_max,
 		    int dlen_max);
+bool		vmbus_chan_rx_empty(const struct vmbus_channel *chan);
+bool		vmbus_chan_tx_empty(const struct vmbus_channel *chan);
 
 #endif	/* !_VMBUS_H_ */
diff --git a/sys/dev/hyperv/vmbus/vmbus_brvar.h b/sys/dev/hyperv/vmbus/vmbus_brvar.h
index bd967f6e869b..cbec3ebdd501 100644
--- a/sys/dev/hyperv/vmbus/vmbus_brvar.h
+++ b/sys/dev/hyperv/vmbus/vmbus_brvar.h
@@ -83,6 +83,20 @@ vmbus_txbr_maxpktsz(const struct vmbus_txbr *tbr)
 	return (tbr->txbr_dsize - sizeof(uint64_t) - 1);
 }
 
+static __inline bool
+vmbus_txbr_empty(const struct vmbus_txbr *tbr)
+{
+
+	return (tbr->txbr_windex == tbr->txbr_rindex ? true : false);
+}
+
+static __inline bool
+vmbus_rxbr_empty(const struct vmbus_rxbr *rbr)
+{
+
+	return (rbr->rxbr_windex == rbr->rxbr_rindex ? true : false);
+}
+
 static __inline int
 vmbus_br_nelem(int br_size, int elem_size)
 {
diff --git a/sys/dev/hyperv/vmbus/vmbus_chan.c b/sys/dev/hyperv/vmbus/vmbus_chan.c
index 1cd9d3719de1..68a80d38790e 100644
--- a/sys/dev/hyperv/vmbus/vmbus_chan.c
+++ b/sys/dev/hyperv/vmbus/vmbus_chan.c
@@ -1692,3 +1692,17 @@ vmbus_chan_prplist_nelem(int br_size, int prpcnt_max, int dlen_max)
 
 	return (vmbus_br_nelem(br_size, elem_size));
 }
+
+bool
+vmbus_chan_tx_empty(const struct vmbus_channel *chan)
+{
+
+	return (vmbus_txbr_empty(&chan->ch_txbr));
+}
+
+bool
+vmbus_chan_rx_empty(const struct vmbus_channel *chan)
+{
+
+	return (vmbus_rxbr_empty(&chan->ch_rxbr));
+}