3 files changed, 37 insertions, 2 deletions

diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h
index 13010b4dae5b..d18f711d0b0c 100644
--- a/drivers/net/hyperv/hyperv_net.h
+++ b/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
  */
diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index 6f39baa67a5f..31e55fba7cad 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -398,7 +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;
 
@@ -438,6 +461,7 @@ do_send:
 
         ret = netvsc_send(net_device_ctx->device_ctx, packet);
 
+drop:
         if (ret == 0) {
                 net->stats.tx_bytes += skb->len;
                 net->stats.tx_packets++;
diff --git a/drivers/net/hyperv/rndis_filter.c b/drivers/net/hyperv/rndis_filter.c
index 4a37e3db9e32..143a98caf618 100644
--- a/drivers/net/hyperv/rndis_filter.c
+++ b/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;
                 }