Index: head/sys/dev/hyperv/vmbus/hv_channel.c
===================================================================
--- head/sys/dev/hyperv/vmbus/hv_channel.c
+++ head/sys/dev/hyperv/vmbus/hv_channel.c
@@ -637,8 +637,8 @@
 
 	pkt.cp_hdr.cph_type = type;
 	pkt.cp_hdr.cph_flags = flags;
-	pkt.cp_hdr.cph_data_ofs = hlen >> VMBUS_CHANPKT_SIZE_SHIFT;
-	pkt.cp_hdr.cph_len = pad_pktlen >> VMBUS_CHANPKT_SIZE_SHIFT;
+	pkt.cp_hdr.cph_hlen = hlen >> VMBUS_CHANPKT_SIZE_SHIFT;
+	pkt.cp_hdr.cph_tlen = pad_pktlen >> VMBUS_CHANPKT_SIZE_SHIFT;
 	pkt.cp_hdr.cph_xactid = xactid;
 
 	iov[0].iov_base = &pkt;
@@ -673,8 +673,8 @@
 
 	pkt.cp_hdr.cph_type = VMBUS_CHANPKT_TYPE_GPA;
 	pkt.cp_hdr.cph_flags = VMBUS_CHANPKT_FLAG_RC;
-	pkt.cp_hdr.cph_data_ofs = hlen >> VMBUS_CHANPKT_SIZE_SHIFT;
-	pkt.cp_hdr.cph_len = pad_pktlen >> VMBUS_CHANPKT_SIZE_SHIFT;
+	pkt.cp_hdr.cph_hlen = hlen >> VMBUS_CHANPKT_SIZE_SHIFT;
+	pkt.cp_hdr.cph_tlen = pad_pktlen >> VMBUS_CHANPKT_SIZE_SHIFT;
 	pkt.cp_hdr.cph_xactid = xactid;
 	pkt.cp_rsvd = 0;
 	pkt.cp_gpa_cnt = sglen;
@@ -715,8 +715,8 @@
 
 	pkt.cp_hdr.cph_type = VMBUS_CHANPKT_TYPE_GPA;
 	pkt.cp_hdr.cph_flags = VMBUS_CHANPKT_FLAG_RC;
-	pkt.cp_hdr.cph_data_ofs = hlen >> VMBUS_CHANPKT_SIZE_SHIFT;
-	pkt.cp_hdr.cph_len = pad_pktlen >> VMBUS_CHANPKT_SIZE_SHIFT;
+	pkt.cp_hdr.cph_hlen = hlen >> VMBUS_CHANPKT_SIZE_SHIFT;
+	pkt.cp_hdr.cph_tlen = pad_pktlen >> VMBUS_CHANPKT_SIZE_SHIFT;
 	pkt.cp_hdr.cph_xactid = xactid;
 	pkt.cp_rsvd = 0;
 	pkt.cp_range_cnt = 1;
Index: head/sys/dev/hyperv/vmbus/vmbus_reg.h
===================================================================
--- head/sys/dev/hyperv/vmbus/vmbus_reg.h
+++ head/sys/dev/hyperv/vmbus/vmbus_reg.h
@@ -117,8 +117,8 @@
 
 struct vmbus_chanpkt_hdr {
 	uint16_t	cph_type;
-	uint16_t	cph_data_ofs;	/* in 8 bytes */
-	uint16_t	cph_len;	/* in 8 bytes */
+	uint16_t	cph_hlen;	/* header len, in 8 bytes */
+	uint16_t	cph_tlen;	/* total len, in 8 bytes */
 	uint16_t	cph_flags;
 	uint64_t	cph_xactid;
 } __packed;