netvsc: negotiate checksum and segmentation parameters

Redo how Hyper-V network driver negotiates offload features. Query the
host to determine offload settings, and use the result.

Also:
  * disable IPv4 header checksum offload (not used by Linux)
  * enable TSO only if host supports
  * enable UDP checksum offload if supported
  * don't advertise support for checksumming of non-IP protocols
  * adjust GSO maximum segment size
  * enable HIGHDMA
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/hyperv/hyperv_net.h

@@ -34,6 +34,7 @@
 
 #define NDIS_OBJECT_TYPE_RSS_CAPABILITIES 0x88
 #define NDIS_OBJECT_TYPE_RSS_PARAMETERS 0x89
+#define NDIS_OBJECT_TYPE_OFFLOAD	0xa7
 
 #define NDIS_RECEIVE_SCALE_CAPABILITIES_REVISION_2 2
 #define NDIS_RECEIVE_SCALE_PARAMETERS_REVISION_2 2
@@ -685,6 +686,7 @@ struct net_device_context {
 	struct work_struct work;
 	u32 msg_enable; /* debug level */
 
+	u32 tx_checksum_mask;
 	struct netvsc_stats __percpu *tx_stats;
 	struct netvsc_stats __percpu *rx_stats;
 
@@ -934,7 +936,7 @@ struct ndis_pkt_8021q_info {
 	};
 };
 
-struct ndis_oject_header {
+struct ndis_object_header {
 	u8 type;
 	u8 revision;
 	u16 size;
@@ -942,6 +944,9 @@ struct ndis_oject_header {
 
 #define NDIS_OBJECT_TYPE_DEFAULT	0x80
 #define NDIS_OFFLOAD_PARAMETERS_REVISION_3 3
+#define NDIS_OFFLOAD_PARAMETERS_REVISION_2 2
+#define NDIS_OFFLOAD_PARAMETERS_REVISION_1 1
+
 #define NDIS_OFFLOAD_PARAMETERS_NO_CHANGE 0
 #define NDIS_OFFLOAD_PARAMETERS_LSOV2_DISABLED 1
 #define NDIS_OFFLOAD_PARAMETERS_LSOV2_ENABLED  2
@@ -968,8 +973,135 @@ struct ndis_oject_header {
 #define OID_TCP_CONNECTION_OFFLOAD_HARDWARE_CAPABILITIES 0xFC01020F /* query */
 #define OID_OFFLOAD_ENCAPSULATION 0x0101010A /* set/query */
 
+/*
+ * OID_TCP_OFFLOAD_HARDWARE_CAPABILITIES
+ * ndis_type: NDIS_OBJTYPE_OFFLOAD
+ */
+
+#define	NDIS_OFFLOAD_ENCAP_NONE		0x0000
+#define	NDIS_OFFLOAD_ENCAP_NULL		0x0001
+#define	NDIS_OFFLOAD_ENCAP_8023		0x0002
+#define	NDIS_OFFLOAD_ENCAP_8023PQ	0x0004
+#define	NDIS_OFFLOAD_ENCAP_8023PQ_OOB	0x0008
+#define	NDIS_OFFLOAD_ENCAP_RFC1483	0x0010
+
+struct ndis_csum_offload {
+	u32	ip4_txenc;
+	u32	ip4_txcsum;
+#define	NDIS_TXCSUM_CAP_IP4OPT		0x001
+#define	NDIS_TXCSUM_CAP_TCP4OPT		0x004
+#define	NDIS_TXCSUM_CAP_TCP4		0x010
+#define	NDIS_TXCSUM_CAP_UDP4		0x040
+#define	NDIS_TXCSUM_CAP_IP4		0x100
+
+#define NDIS_TXCSUM_ALL_TCP4	(NDIS_TXCSUM_CAP_TCP4 | NDIS_TXCSUM_CAP_TCP4OPT)
+
+	u32	ip4_rxenc;
+	u32	ip4_rxcsum;
+#define	NDIS_RXCSUM_CAP_IP4OPT		0x001
+#define	NDIS_RXCSUM_CAP_TCP4OPT		0x004
+#define	NDIS_RXCSUM_CAP_TCP4		0x010
+#define	NDIS_RXCSUM_CAP_UDP4		0x040
+#define	NDIS_RXCSUM_CAP_IP4		0x100
+	u32	ip6_txenc;
+	u32	ip6_txcsum;
+#define	NDIS_TXCSUM_CAP_IP6EXT		0x001
+#define	NDIS_TXCSUM_CAP_TCP6OPT		0x004
+#define	NDIS_TXCSUM_CAP_TCP6		0x010
+#define	NDIS_TXCSUM_CAP_UDP6		0x040
+	u32	ip6_rxenc;
+	u32	ip6_rxcsum;
+#define	NDIS_RXCSUM_CAP_IP6EXT		0x001
+#define	NDIS_RXCSUM_CAP_TCP6OPT		0x004
+#define	NDIS_RXCSUM_CAP_TCP6		0x010
+#define	NDIS_RXCSUM_CAP_UDP6		0x040
+
+#define NDIS_TXCSUM_ALL_TCP6	(NDIS_TXCSUM_CAP_TCP6 |		\
+				 NDIS_TXCSUM_CAP_TCP6OPT |	\
+				 NDIS_TXCSUM_CAP_IP6EXT)
+};
+
+struct ndis_lsov1_offload {
+	u32	encap;
+	u32	maxsize;
+	u32	minsegs;
+	u32	opts;
+};
+
+struct ndis_ipsecv1_offload {
+	u32	encap;
+	u32	ah_esp;
+	u32	xport_tun;
+	u32	ip4_opts;
+	u32	flags;
+	u32	ip4_ah;
+	u32	ip4_esp;
+};
+
+struct ndis_lsov2_offload {
+	u32	ip4_encap;
+	u32	ip4_maxsz;
+	u32	ip4_minsg;
+	u32	ip6_encap;
+	u32	ip6_maxsz;
+	u32	ip6_minsg;
+	u32	ip6_opts;
+#define	NDIS_LSOV2_CAP_IP6EXT		0x001
+#define	NDIS_LSOV2_CAP_TCP6OPT		0x004
+
+#define NDIS_LSOV2_CAP_IP6		(NDIS_LSOV2_CAP_IP6EXT | \
+					 NDIS_LSOV2_CAP_TCP6OPT)
+};
+
+struct ndis_ipsecv2_offload {
+	u32	encap;
+	u16	ip6;
+	u16	ip4opt;
+	u16	ip6ext;
+	u16	ah;
+	u16	esp;
+	u16	ah_esp;
+	u16	xport;
+	u16	tun;
+	u16	xport_tun;
+	u16	lso;
+	u16	extseq;
+	u32	udp_esp;
+	u32	auth;
+	u32	crypto;
+	u32	sa_caps;
+};
+
+struct ndis_rsc_offload {
+	u16	ip4;
+	u16	ip6;
+};
+
+struct ndis_encap_offload {
+	u32	flags;
+	u32	maxhdr;
+};
+
+struct ndis_offload {
+	struct ndis_object_header	header;
+	struct ndis_csum_offload	csum;
+	struct ndis_lsov1_offload	lsov1;
+	struct ndis_ipsecv1_offload	ipsecv1;
+	struct ndis_lsov2_offload	lsov2;
+	u32				flags;
+	/* NDIS >= 6.1 */
+	struct ndis_ipsecv2_offload	ipsecv2;
+	/* NDIS >= 6.30 */
+	struct ndis_rsc_offload		rsc;
+	struct ndis_encap_offload	encap_gre;
+};
+
+#define	NDIS_OFFLOAD_SIZE		sizeof(struct ndis_offload)
+#define	NDIS_OFFLOAD_SIZE_6_0		offsetof(struct ndis_offload, ipsecv2)
+#define	NDIS_OFFLOAD_SIZE_6_1		offsetof(struct ndis_offload, rsc)
+
 struct ndis_offload_params {
-	struct ndis_oject_header header;
+	struct ndis_object_header header;
 	u8 ip_v4_csum;
 	u8 tcp_ip_v4_csum;
 	u8 udp_ip_v4_csum;
@@ -1296,15 +1428,10 @@ struct rndis_message {
 #define NDIS_PACKET_TYPE_FUNCTIONAL	0x00000400
 #define NDIS_PACKET_TYPE_MAC_FRAME	0x00000800
 
-#define INFO_IPV4       2
-#define INFO_IPV6       4
-#define INFO_TCP        2
-#define INFO_UDP        4
-
 #define TRANSPORT_INFO_NOT_IP   0
-#define TRANSPORT_INFO_IPV4_TCP ((INFO_IPV4 << 16) | INFO_TCP)
-#define TRANSPORT_INFO_IPV4_UDP ((INFO_IPV4 << 16) | INFO_UDP)
-#define TRANSPORT_INFO_IPV6_TCP ((INFO_IPV6 << 16) | INFO_TCP)
-#define TRANSPORT_INFO_IPV6_UDP ((INFO_IPV6 << 16) | INFO_UDP)
+#define TRANSPORT_INFO_IPV4_TCP 0x01
+#define TRANSPORT_INFO_IPV4_UDP 0x02
+#define TRANSPORT_INFO_IPV6_TCP 0x10
+#define TRANSPORT_INFO_IPV6_UDP 0x20
 
 #endif /* _HYPERV_NET_H */

drivers/net/hyperv/netvsc_drv.c

@@ -42,14 +42,6 @@
 
 #define RING_SIZE_MIN 64
 #define LINKCHANGE_INT (2 * HZ)
-#define NETVSC_HW_FEATURES	(NETIF_F_RXCSUM | \
-				 NETIF_F_SG | \
-				 NETIF_F_TSO | \
-				 NETIF_F_TSO6 | \
-				 NETIF_F_HW_CSUM)
-
-/* Restrict GSO size to account for NVGRE */
-#define NETVSC_GSO_MAX_SIZE	62768
 
 static int ring_size = 128;
 module_param(ring_size, int, S_IRUGO);
@@ -323,33 +315,25 @@ static int netvsc_get_slots(struct sk_buff *skb)
 	return slots + frag_slots;
 }
 
-static u32 get_net_transport_info(struct sk_buff *skb, u32 *trans_off)
+static u32 net_checksum_info(struct sk_buff *skb)
 {
-	u32 ret_val = TRANSPORT_INFO_NOT_IP;
-
-	if ((eth_hdr(skb)->h_proto != htons(ETH_P_IP)) &&
-		(eth_hdr(skb)->h_proto != htons(ETH_P_IPV6))) {
-		goto not_ip;
-	}
+	if (skb->protocol == htons(ETH_P_IP)) {
+		struct iphdr *ip = ip_hdr(skb);
 
-	*trans_off = skb_transport_offset(skb);
-
-	if ((eth_hdr(skb)->h_proto == htons(ETH_P_IP))) {
-		struct iphdr *iphdr = ip_hdr(skb);
-
-		if (iphdr->protocol == IPPROTO_TCP)
-			ret_val = TRANSPORT_INFO_IPV4_TCP;
-		else if (iphdr->protocol == IPPROTO_UDP)
-			ret_val = TRANSPORT_INFO_IPV4_UDP;
+		if (ip->protocol == IPPROTO_TCP)
+			return TRANSPORT_INFO_IPV4_TCP;
+		else if (ip->protocol == IPPROTO_UDP)
+			return TRANSPORT_INFO_IPV4_UDP;
 	} else {
-		if (ipv6_hdr(skb)->nexthdr == IPPROTO_TCP)
-			ret_val = TRANSPORT_INFO_IPV6_TCP;
+		struct ipv6hdr *ip6 = ipv6_hdr(skb);
+
+		if (ip6->nexthdr == IPPROTO_TCP)
+			return TRANSPORT_INFO_IPV6_TCP;
 		else if (ipv6_hdr(skb)->nexthdr == IPPROTO_UDP)
-			ret_val = TRANSPORT_INFO_IPV6_UDP;
+			return TRANSPORT_INFO_IPV6_UDP;
 	}
 
-not_ip:
-	return ret_val;
+	return TRANSPORT_INFO_NOT_IP;
 }
 
 static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)
@@ -362,9 +346,6 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)
 	struct rndis_packet *rndis_pkt;
 	u32 rndis_msg_size;
 	struct rndis_per_packet_info *ppi;
-	struct ndis_tcp_ip_checksum_info *csum_info;
-	int  hdr_offset;
-	u32 net_trans_info;
 	u32 hash;
 	u32 skb_length;
 	struct hv_page_buffer page_buf[MAX_PAGE_BUFFER_COUNT];
@@ -445,13 +426,7 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)
 				VLAN_PRIO_SHIFT;
 	}
 
-	net_trans_info = get_net_transport_info(skb, &hdr_offset);
-
-	/*
-	 * Setup the sendside checksum offload only if this is not a
-	 * GSO packet.
-	 */
-	if ((net_trans_info & (INFO_TCP | INFO_UDP)) && skb_is_gso(skb)) {
+	if (skb_is_gso(skb)) {
 		struct ndis_tcp_lso_info *lso_info;
 
 		rndis_msg_size += NDIS_LSO_PPI_SIZE;
@@ -462,7 +437,7 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)
 							ppi->ppi_offset);
 
 		lso_info->lso_v2_transmit.type = NDIS_TCP_LARGE_SEND_OFFLOAD_V2_TYPE;
-		if (net_trans_info & (INFO_IPV4 << 16)) {
+		if (skb->protocol == htons(ETH_P_IP)) {
 			lso_info->lso_v2_transmit.ip_version =
 				NDIS_TCP_LARGE_SEND_OFFLOAD_IPV4;
 			ip_hdr(skb)->tot_len = 0;
@@ -478,10 +453,12 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)
 				~csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
 						 &ipv6_hdr(skb)->daddr, 0, IPPROTO_TCP, 0);
 		}
-		lso_info->lso_v2_transmit.tcp_header_offset = hdr_offset;
+		lso_info->lso_v2_transmit.tcp_header_offset = skb_transport_offset(skb);
 		lso_info->lso_v2_transmit.mss = skb_shinfo(skb)->gso_size;
 	} else if (skb->ip_summed == CHECKSUM_PARTIAL) {
-		if (net_trans_info & INFO_TCP) {
+		if (net_checksum_info(skb) & net_device_ctx->tx_checksum_mask) {
+			struct ndis_tcp_ip_checksum_info *csum_info;
+
 			rndis_msg_size += NDIS_CSUM_PPI_SIZE;
 			ppi = init_ppi_data(rndis_msg, NDIS_CSUM_PPI_SIZE,
 					    TCPIP_CHKSUM_PKTINFO);
@@ -489,15 +466,25 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)
 			csum_info = (struct ndis_tcp_ip_checksum_info *)((void *)ppi +
 									 ppi->ppi_offset);
 
-			if (net_trans_info & (INFO_IPV4 << 16))
+			csum_info->transmit.tcp_header_offset = skb_transport_offset(skb);
+
+			if (skb->protocol == htons(ETH_P_IP)) {
 				csum_info->transmit.is_ipv4 = 1;
+
+				if (ip_hdr(skb)->protocol == IPPROTO_TCP)
+					csum_info->transmit.tcp_checksum = 1;
 				else
+					csum_info->transmit.udp_checksum = 1;
+			} else {
 				csum_info->transmit.is_ipv6 = 1;
 
+				if (ipv6_hdr(skb)->nexthdr == IPPROTO_TCP)
 					csum_info->transmit.tcp_checksum = 1;
-			csum_info->transmit.tcp_header_offset = hdr_offset;
+				else
+					csum_info->transmit.udp_checksum = 1;
+			}
 		} else {
-			/* UDP checksum (and other) offload is not supported. */
+			/* Can't do offload of this type of checksum */
 			if (skb_checksum_help(skb))
 				goto drop;
 		}
@@ -1372,10 +1359,6 @@ static int netvsc_probe(struct hv_device *dev,
 	INIT_LIST_HEAD(&net_device_ctx->reconfig_events);
 
 	net->netdev_ops = &device_ops;
-
-	net->hw_features = NETVSC_HW_FEATURES;
-	net->features = NETVSC_HW_FEATURES | NETIF_F_HW_VLAN_CTAG_TX;
-
 	net->ethtool_ops = &ethtool_ops;
 	SET_NETDEV_DEV(net, &dev->device);
 
@@ -1395,10 +1378,15 @@ static int netvsc_probe(struct hv_device *dev,
 	}
 	memcpy(net->dev_addr, device_info.mac_adr, ETH_ALEN);
 
+	/* hw_features computed in rndis_filter_device_add */
+	net->features = net->hw_features |
+		NETIF_F_HIGHDMA | NETIF_F_SG |
+		NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_CTAG_RX;
+	net->vlan_features = net->features;
+
 	nvdev = net_device_ctx->nvdev;
 	netif_set_real_num_tx_queues(net, nvdev->num_chn);
 	netif_set_real_num_rx_queues(net, nvdev->num_chn);
-	netif_set_gso_max_size(net, NETVSC_GSO_MAX_SIZE);
 
 	/* MTU range: 68 - 1500 or 65521 */
 	net->min_mtu = NETVSC_MTU_MIN;

drivers/net/hyperv/rndis_filter.c

@@ -485,7 +485,35 @@ static int rndis_filter_query_device(struct rndis_device *dev, u32 oid,
 	query->info_buflen = 0;
 	query->dev_vc_handle = 0;
 
-	if (oid == OID_GEN_RECEIVE_SCALE_CAPABILITIES) {
+	if (oid == OID_TCP_OFFLOAD_HARDWARE_CAPABILITIES) {
+		struct net_device_context *ndevctx = netdev_priv(dev->ndev);
+		struct netvsc_device *nvdev = ndevctx->nvdev;
+		struct ndis_offload *hwcaps;
+		u32 nvsp_version = nvdev->nvsp_version;
+		u8 ndis_rev;
+		size_t size;
+
+		if (nvsp_version >= NVSP_PROTOCOL_VERSION_5) {
+			ndis_rev = NDIS_OFFLOAD_PARAMETERS_REVISION_3;
+			size = NDIS_OFFLOAD_SIZE;
+		} else if (nvsp_version >= NVSP_PROTOCOL_VERSION_4) {
+			ndis_rev = NDIS_OFFLOAD_PARAMETERS_REVISION_2;
+			size = NDIS_OFFLOAD_SIZE_6_1;
+		} else {
+			ndis_rev = NDIS_OFFLOAD_PARAMETERS_REVISION_1;
+			size = NDIS_OFFLOAD_SIZE_6_0;
+		}
+
+		request->request_msg.msg_len += size;
+		query->info_buflen = size;
+		hwcaps = (struct ndis_offload *)
+			((unsigned long)query + query->info_buf_offset);
+
+		hwcaps->header.type = NDIS_OBJECT_TYPE_OFFLOAD;
+		hwcaps->header.revision = ndis_rev;
+		hwcaps->header.size = size;
+
+	} else if (oid == OID_GEN_RECEIVE_SCALE_CAPABILITIES) {
 		struct ndis_recv_scale_cap *cap;
 
 		request->request_msg.msg_len +=
@@ -526,6 +554,44 @@ static int rndis_filter_query_device(struct rndis_device *dev, u32 oid,
 	return ret;
 }
 
+/* Get the hardware offload capabilities */
+static int
+rndis_query_hwcaps(struct rndis_device *dev, struct ndis_offload *caps)
+{
+	u32 caps_len = sizeof(*caps);
+	int ret;
+
+	memset(caps, 0, sizeof(*caps));
+
+	ret = rndis_filter_query_device(dev,
+					OID_TCP_OFFLOAD_HARDWARE_CAPABILITIES,
+					caps, &caps_len);
+	if (ret)
+		return ret;
+
+	if (caps->header.type != NDIS_OBJECT_TYPE_OFFLOAD) {
+		netdev_warn(dev->ndev, "invalid NDIS objtype %#x\n",
+			    caps->header.type);
+		return -EINVAL;
+	}
+
+	if (caps->header.revision < NDIS_OFFLOAD_PARAMETERS_REVISION_1) {
+		netdev_warn(dev->ndev, "invalid NDIS objrev %x\n",
+			    caps->header.revision);
+		return -EINVAL;
+	}
+
+	if (caps->header.size > caps_len ||
+	    caps->header.size < NDIS_OFFLOAD_SIZE_6_0) {
+		netdev_warn(dev->ndev,
+			    "invalid NDIS objsize %u, data size %u\n",
+			    caps->header.size, caps_len);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 static int rndis_filter_query_device_mac(struct rndis_device *dev)
 {
 	u32 size = ETH_ALEN;
@@ -974,10 +1040,12 @@ int rndis_filter_device_add(struct hv_device *dev,
 	struct netvsc_device *net_device;
 	struct rndis_device *rndis_device;
 	struct netvsc_device_info *device_info = additional_info;
+	struct ndis_offload hwcaps;
 	struct ndis_offload_params offloads;
 	struct nvsp_message *init_packet;
 	struct ndis_recv_scale_cap rsscap;
 	u32 rsscap_size = sizeof(struct ndis_recv_scale_cap);
+	unsigned int gso_max_size = GSO_MAX_SIZE;
 	u32 mtu, size;
 	u32 num_rss_qs;
 	u32 sc_delta;
@@ -1034,19 +1102,65 @@ int rndis_filter_device_add(struct hv_device *dev,
 
 	memcpy(device_info->mac_adr, rndis_device->hw_mac_adr, ETH_ALEN);
 
-	/* Turn on the offloads; the host supports all of the relevant
-	 * offloads.
-	 */
+	/* Find HW offload capabilities */
+	ret = rndis_query_hwcaps(rndis_device, &hwcaps);
+	if (ret != 0) {
+		rndis_filter_device_remove(dev);
+		return ret;
+	}
+
+	/* A value of zero means "no change"; now turn on what we want. */
 	memset(&offloads, 0, sizeof(struct ndis_offload_params));
-	/* A value of zero means "no change"; now turn on what we
-	 * want.
-	 */
-	offloads.ip_v4_csum = NDIS_OFFLOAD_PARAMETERS_TX_RX_ENABLED;
+
+	/* Linux does not care about IP checksum, always does in kernel */
+	offloads.ip_v4_csum = NDIS_OFFLOAD_PARAMETERS_TX_RX_DISABLED;
+
+	/* Compute tx offload settings based on hw capabilities */
+	net->hw_features = NETIF_F_RXCSUM;
+
+	if ((hwcaps.csum.ip4_txcsum & NDIS_TXCSUM_ALL_TCP4) == NDIS_TXCSUM_ALL_TCP4) {
+		/* Can checksum TCP */
+		net->hw_features |= NETIF_F_IP_CSUM;
+		net_device_ctx->tx_checksum_mask |= TRANSPORT_INFO_IPV4_TCP;
+
 		offloads.tcp_ip_v4_csum = NDIS_OFFLOAD_PARAMETERS_TX_RX_ENABLED;
+
+		if (hwcaps.lsov2.ip4_encap & NDIS_OFFLOAD_ENCAP_8023) {
+			offloads.lso_v2_ipv4 = NDIS_OFFLOAD_PARAMETERS_LSOV2_ENABLED;
+			net->hw_features |= NETIF_F_TSO;
+
+			if (hwcaps.lsov2.ip4_maxsz < gso_max_size)
+				gso_max_size = hwcaps.lsov2.ip4_maxsz;
+		}
+
+		if (hwcaps.csum.ip4_txcsum & NDIS_TXCSUM_CAP_UDP4) {
 			offloads.udp_ip_v4_csum = NDIS_OFFLOAD_PARAMETERS_TX_RX_ENABLED;
+			net_device_ctx->tx_checksum_mask |= TRANSPORT_INFO_IPV4_UDP;
+		}
+	}
+
+	if ((hwcaps.csum.ip6_txcsum & NDIS_TXCSUM_ALL_TCP6) == NDIS_TXCSUM_ALL_TCP6) {
+		net->hw_features |= NETIF_F_IPV6_CSUM;
+
 		offloads.tcp_ip_v6_csum = NDIS_OFFLOAD_PARAMETERS_TX_RX_ENABLED;
+		net_device_ctx->tx_checksum_mask |= TRANSPORT_INFO_IPV6_TCP;
+
+		if ((hwcaps.lsov2.ip6_encap & NDIS_OFFLOAD_ENCAP_8023) &&
+		    (hwcaps.lsov2.ip6_opts & NDIS_LSOV2_CAP_IP6) == NDIS_LSOV2_CAP_IP6) {
+			offloads.lso_v2_ipv6 = NDIS_OFFLOAD_PARAMETERS_LSOV2_ENABLED;
+			net->hw_features |= NETIF_F_TSO6;
+
+			if (hwcaps.lsov2.ip6_maxsz < gso_max_size)
+				gso_max_size = hwcaps.lsov2.ip6_maxsz;
+		}
+
+		if (hwcaps.csum.ip6_txcsum & NDIS_TXCSUM_CAP_UDP6) {
 			offloads.udp_ip_v6_csum = NDIS_OFFLOAD_PARAMETERS_TX_RX_ENABLED;
-	offloads.lso_v2_ipv4 = NDIS_OFFLOAD_PARAMETERS_LSOV2_ENABLED;
+			net_device_ctx->tx_checksum_mask |= TRANSPORT_INFO_IPV6_UDP;
+		}
+	}
+
+	netif_set_gso_max_size(net, gso_max_size);
 
 	ret = rndis_filter_set_offload_params(net, &offloads);
 	if (ret)