2 files changed, 34 insertions, 9 deletions

diff --git a/sys/dev/hyperv/utilities/vmbus_icreg.h b/sys/dev/hyperv/utilities/vmbus_icreg.h
index fea74f020b95..e962102d13dd 100644
--- a/sys/dev/hyperv/utilities/vmbus_icreg.h
+++ b/sys/dev/hyperv/utilities/vmbus_icreg.h
@@ -114,8 +114,17 @@ struct vmbus_icmsg_timesync {
 	struct vmbus_icmsg_hdr	ic_hdr;
 	uint64_t		ic_hvtime;
 	uint64_t		ic_vmtime;
+	uint64_t		ic_rtt;
+	uint8_t			ic_tsflags;	/* VMBUS_ICMSG_TS_FLAG_ */
+} __packed;
+
+/* VMBUS_ICMSG_TYPE_TIMESYNC, MSGVER4 */
+struct vmbus_icmsg_timesync4 {
+	struct vmbus_icmsg_hdr	ic_hdr;
+	uint64_t		ic_hvtime;
 	uint64_t		ic_sent_tc;
 	uint8_t			ic_tsflags;	/* VMBUS_ICMSG_TS_FLAG_ */
+	uint8_t			ic_rsvd[5];
 } __packed;
 
 #define VMBUS_ICMSG_TS_FLAG_SYNC	0x01
diff --git a/sys/dev/hyperv/utilities/vmbus_timesync.c b/sys/dev/hyperv/utilities/vmbus_timesync.c
index 89e6b4768e25..d00e1e41ea09 100644
--- a/sys/dev/hyperv/utilities/vmbus_timesync.c
+++ b/sys/dev/hyperv/utilities/vmbus_timesync.c
@@ -48,8 +48,11 @@ __FBSDID("$FreeBSD$");
 #define VMBUS_TIMESYNC_MSGVER		\
 	VMBUS_IC_VERSION(VMBUS_TIMESYNC_MSGVER_MAJOR, 0)
 
+#define VMBUS_TIMESYNC_MSGVER4(sc)	\
+	VMBUS_ICVER_LE(VMBUS_IC_VERSION(4, 0), (sc)->ic_msgver)
+
 #define VMBUS_TIMESYNC_DORTT(sc)	\
-	((sc)->ic_msgver >= VMBUS_IC_VERSION(4, 0) && \
+	(VMBUS_TIMESYNC_MSGVER4((sc)) &&\
 	 (hyperv_features & CPUID_HV_MSR_TIME_REFCNT))
 
 static int			vmbus_timesync_probe(device_t);
@@ -174,7 +177,6 @@ vmbus_timesync_cb(struct vmbus_channel *chan, void *xsc)
 {
 	struct vmbus_ic_softc *sc = xsc;
 	struct vmbus_icmsg_hdr *hdr;
-	const struct vmbus_icmsg_timesync *msg;
 	int dlen, error;
 	uint64_t xactid;
 	void *data;
@@ -209,14 +211,28 @@ vmbus_timesync_cb(struct vmbus_channel *chan, void *xsc)
 		break;
 
 	case VMBUS_ICMSG_TYPE_TIMESYNC:
-		if (dlen < sizeof(*msg)) {
-			device_printf(sc->ic_dev, "invalid timesync len %d\n",
-			    dlen);
-			return;
+		if (VMBUS_TIMESYNC_MSGVER4(sc)) {
+			const struct vmbus_icmsg_timesync4 *msg4;
+
+			if (dlen < sizeof(*msg4)) {
+				device_printf(sc->ic_dev, "invalid timesync4 "
+				    "len %d\n", dlen);
+				return;
+			}
+			msg4 = data;
+			vmbus_timesync(sc, msg4->ic_hvtime, msg4->ic_sent_tc,
+			    msg4->ic_tsflags);
+		} else {
+			const struct vmbus_icmsg_timesync *msg;
+
+			if (dlen < sizeof(*msg)) {
+				device_printf(sc->ic_dev, "invalid timesync "
+				    "len %d\n", dlen);
+				return;
+			}
+			msg = data;
+			vmbus_timesync(sc, msg->ic_hvtime, 0, msg->ic_tsflags);
 		}
-		msg = data;
-		vmbus_timesync(sc, msg->ic_hvtime, msg->ic_sent_tc,
-		    msg->ic_tsflags);
 		break;
 
 	default: