Merge branch 'hyperv'

K. Y. Srinivasan says:

====================
Fix issues with Heper-V network offload code

WS2008 R2 does not support udp checksum offload. Furthermore, ws2012 and
ws2012 r2 have issues offloading udp checksum from Linux guests.
This patch-set addresses these issues as well as other bug fixes.
Please apply.

In this version, I have addressed the comment from David Miller with reagards
to COWing the skb prior to modifying the header (patch 3/3).
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/hyperv/hyperv_net.h

@@ -747,6 +747,7 @@ struct ndis_oject_header {
 #define NDIS_TCP_LARGE_SEND_OFFLOAD_IPV4	0
 #define NDIS_TCP_LARGE_SEND_OFFLOAD_IPV6	1
 
+#define VERSION_4_OFFLOAD_SIZE			22
 /*
  * New offload OIDs for NDIS 6
  */

drivers/net/hyperv/netvsc.c

@@ -344,7 +344,7 @@ static int netvsc_connect_vsp(struct hv_device *device)
 	memset(init_packet, 0, sizeof(struct nvsp_message));
 
 	if (net_device->nvsp_version <= NVSP_PROTOCOL_VERSION_4)
-		ndis_version = 0x00050001;
+		ndis_version = 0x00060001;
 	else
 		ndis_version = 0x0006001e;
 

drivers/net/hyperv/netvsc_drv.c

@@ -319,7 +319,9 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)
 	packet = kzalloc(sizeof(struct hv_netvsc_packet) +
 			 (num_data_pgs * sizeof(struct hv_page_buffer)) +
 			 sizeof(struct rndis_message) +
-			 NDIS_VLAN_PPI_SIZE, GFP_ATOMIC);
+			 NDIS_VLAN_PPI_SIZE +
+			 NDIS_CSUM_PPI_SIZE +
+			 NDIS_LSO_PPI_SIZE, GFP_ATOMIC);
 	if (!packet) {
 		/* out of memory, drop packet */
 		netdev_err(net, "unable to allocate hv_netvsc_packet\n");
@@ -396,7 +398,30 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)
 		csum_info->transmit.tcp_checksum = 1;
 		csum_info->transmit.tcp_header_offset = hdr_offset;
 	} else if (net_trans_info & INFO_UDP) {
-		csum_info->transmit.udp_checksum = 1;
+		/* UDP checksum offload is not supported on ws2008r2.
+		 * Furthermore, on ws2012 and ws2012r2, there are some
+		 * issues with udp checksum offload from Linux guests.
+		 * (these are host issues).
+		 * For now compute the checksum here.
+		 */
+		struct udphdr *uh;
+		u16 udp_len;
+
+		ret = skb_cow_head(skb, 0);
+		if (ret)
+			goto drop;
+
+		uh = udp_hdr(skb);
+		udp_len = ntohs(uh->len);
+		uh->check = 0;
+		uh->check = csum_tcpudp_magic(ip_hdr(skb)->saddr,
+					      ip_hdr(skb)->daddr,
+					      udp_len, IPPROTO_UDP,
+					      csum_partial(uh, udp_len, 0));
+		if (uh->check == 0)
+			uh->check = CSUM_MANGLED_0;
+
+		csum_info->transmit.udp_checksum = 0;
 	}
 	goto do_send;
 
@@ -436,6 +461,7 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)
 
 	ret = netvsc_send(net_device_ctx->device_ctx, packet);
 
+drop:
 	if (ret == 0) {
 		net->stats.tx_bytes += skb->len;
 		net->stats.tx_packets++;

drivers/net/hyperv/rndis_filter.c

@@ -641,6 +641,16 @@ int rndis_filter_set_offload_params(struct hv_device *hdev,
 	struct rndis_set_complete *set_complete;
 	u32 extlen = sizeof(struct ndis_offload_params);
 	int ret, t;
+	u32 vsp_version = nvdev->nvsp_version;
+
+	if (vsp_version <= NVSP_PROTOCOL_VERSION_4) {
+		extlen = VERSION_4_OFFLOAD_SIZE;
+		/* On NVSP_PROTOCOL_VERSION_4 and below, we do not support
+		 * UDP checksum offload.
+		 */
+		req_offloads->udp_ip_v4_csum = 0;
+		req_offloads->udp_ip_v6_csum = 0;
+	}
 
 	request = get_rndis_request(rdev, RNDIS_MSG_SET,
 		RNDIS_MESSAGE_SIZE(struct rndis_set_request) + extlen);
@@ -674,7 +684,7 @@ int rndis_filter_set_offload_params(struct hv_device *hdev,
 	} else {
 		set_complete = &request->response_msg.msg.set_complete;
 		if (set_complete->status != RNDIS_STATUS_SUCCESS) {
-			netdev_err(ndev, "Fail to set MAC on host side:0x%x\n",
+			netdev_err(ndev, "Fail to set offload on host side:0x%x\n",
 				   set_complete->status);
 			ret = -EINVAL;
 		}