Index: head/sys/dev/hyperv/netvsc/hv_netvsc_drv_freebsd.c
===================================================================
--- head/sys/dev/hyperv/netvsc/hv_netvsc_drv_freebsd.c
+++ head/sys/dev/hyperv/netvsc/hv_netvsc_drv_freebsd.c
@@ -910,6 +910,7 @@
 	}
 
 	if (m_head->m_pkthdr.csum_flags & CSUM_TSO) {
+#if defined(INET6) || defined(INET)
 		rndis_tcp_tso_info *tso_info;	
 		struct ether_vlan_header *eh;
 		int ether_len;
@@ -929,8 +930,6 @@
 
 		tso_info = (rndis_tcp_tso_info *)((uint8_t *)rppi +
 		    rppi->per_packet_info_offset);
-		tso_info->lso_v2_xmit.type =
-		    RNDIS_TCP_LARGE_SEND_OFFLOAD_V2_TYPE;
 
 #ifdef INET
 		if (m_head->m_pkthdr.csum_flags & CSUM_IP_TSO) {
@@ -940,13 +939,12 @@
 			struct tcphdr *th =
 			    (struct tcphdr *)((caddr_t)ip + iph_len);
 
-			tso_info->lso_v2_xmit.ip_version =
-			    RNDIS_TCP_LARGE_SEND_OFFLOAD_IPV4;
 			ip->ip_len = 0;
 			ip->ip_sum = 0;
-
 			th->th_sum = in_pseudo(ip->ip_src.s_addr,
 			    ip->ip_dst.s_addr, htons(IPPROTO_TCP));
+			tso_info->value = NDIS_LSO2_INFO_MAKEIPV4(0,
+			    m_head->m_pkthdr.tso_segsz);
 		}
 #endif
 #if defined(INET6) && defined(INET)
@@ -958,14 +956,13 @@
 			    (m_head->m_data + ether_len);
 			struct tcphdr *th = (struct tcphdr *)(ip6 + 1);
 
-			tso_info->lso_v2_xmit.ip_version =
-			    RNDIS_TCP_LARGE_SEND_OFFLOAD_IPV6;
 			ip6->ip6_plen = 0;
 			th->th_sum = in6_cksum_pseudo(ip6, 0, IPPROTO_TCP, 0);
+			tso_info->value = NDIS_LSO2_INFO_MAKEIPV6(0,
+			    m_head->m_pkthdr.tso_segsz);
 		}
 #endif
-		tso_info->lso_v2_xmit.tcp_header_offset = 0;
-		tso_info->lso_v2_xmit.mss = m_head->m_pkthdr.tso_segsz;
+#endif	/* INET6 || INET */
 	} else if (m_head->m_pkthdr.csum_flags & txr->hn_csum_assist) {
 		rndis_tcp_ip_csum_info *csum_info;
 
Index: head/sys/dev/hyperv/netvsc/ndis.h
===================================================================
--- head/sys/dev/hyperv/netvsc/ndis.h
+++ head/sys/dev/hyperv/netvsc/ndis.h
@@ -231,4 +231,21 @@
 #define	NDIS_RXCSUM_INFO_TCPCS_INVAL	0x0080
 #define	NDIS_RXCSUM_INFO_IPCS_INVAL	0x0100
 
+/* LSOv2 */
+#define	NDIS_LSO2_INFO_MSS_MASK		0x000fffff
+#define	NDIS_LSO2_INFO_THOFF_MASK	0x3ff00000
+#define	NDIS_LSO2_INFO_ISLSO2		0x40000000
+#define	NDIS_LSO2_INFO_ISIPV6		0x80000000
+
+#define	NDIS_LSO2_INFO_MAKE(thoff, mss)				\
+	((((uint32_t)(mss)) & NDIS_LSO2_INFO_MSS_MASK) |	\
+	 ((((uint32_t)(thoff)) & 0x3ff) << 20) |		\
+	 NDIS_LSO2_INFO_ISLSO2)
+
+#define	NDIS_LSO2_INFO_MAKEIPV4(thoff, mss)			\
+	NDIS_LSO2_INFO_MAKE((thoff), (mss))
+
+#define	NDIS_LSO2_INFO_MAKEIPV6(thoff, mss)			\
+	(NDIS_LSO2_INFO_MAKE((thoff), (mss)) | NDIS_LSO2_INFO_ISIPV6)
+
 #endif	/* !_NET_NDIS_H_ */