hv_netvsc: Add support for LRO/RSC in the vSwitch

LRO/RSC in the vSwitch is a feature available in Windows Server 2019
hosts and later. It reduces the per packet processing overhead by
coalescing multiple TCP segments when possible. This patch adds netvsc
driver support for this feature.

Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 13 insertions, 5 deletions

diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
index fe01e141c8f8..922054c1d544 100644
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c
@@ -542,6 +542,9 @@ static int negotiate_nvsp_ver(struct hv_device *device,
 		init_packet->msg.v2_msg.send_ndis_config.capability.teaming = 1;
 	}
 
+	if (nvsp_ver >= NVSP_PROTOCOL_VERSION_61)
+		init_packet->msg.v2_msg.send_ndis_config.capability.rsc = 1;
+
 	trace_nvsp_send(ndev, init_packet);
 
 	ret = vmbus_sendpacket(device->channel, init_packet,
@@ -1111,11 +1114,12 @@ static void enq_receive_complete(struct net_device *ndev,
 
 static int netvsc_receive(struct net_device *ndev,
 			  struct netvsc_device *net_device,
-			  struct vmbus_channel *channel,
+			  struct netvsc_channel *nvchan,
 			  const struct vmpacket_descriptor *desc,
 			  const struct nvsp_message *nvsp)
 {
 	struct net_device_context *net_device_ctx = netdev_priv(ndev);
+	struct vmbus_channel *channel = nvchan->channel;
 	const struct vmtransfer_page_packet_header *vmxferpage_packet
 		= container_of(desc, const struct vmtransfer_page_packet_header, d);
 	u16 q_idx = channel->offermsg.offer.sub_channel_index;
@@ -1150,6 +1154,7 @@ static int netvsc_receive(struct net_device *ndev,
 		int ret;
 
 		if (unlikely(offset + buflen > net_device->recv_buf_size)) {
+			nvchan->rsc.cnt = 0;
 			status = NVSP_STAT_FAIL;
 			netif_err(net_device_ctx, rx_err, ndev,
 				  "Packet offset:%u + len:%u too big\n",
@@ -1160,11 +1165,13 @@ static int netvsc_receive(struct net_device *ndev,
 
 		data = recv_buf + offset;
 
+		nvchan->rsc.is_last = (i == count - 1);
+
 		trace_rndis_recv(ndev, q_idx, data);
 
 		/* Pass it to the upper layer */
 		ret = rndis_filter_receive(ndev, net_device,
-					   channel, data, buflen);
+					   nvchan, data, buflen);
 
 		if (unlikely(ret != NVSP_STAT_SUCCESS))
 			status = NVSP_STAT_FAIL;
@@ -1223,12 +1230,13 @@ static  void netvsc_receive_inband(struct net_device *ndev,
 }
 
 static int netvsc_process_raw_pkt(struct hv_device *device,
-				  struct vmbus_channel *channel,
+				  struct netvsc_channel *nvchan,
 				  struct netvsc_device *net_device,
 				  struct net_device *ndev,
 				  const struct vmpacket_descriptor *desc,
 				  int budget)
 {
+	struct vmbus_channel *channel = nvchan->channel;
 	const struct nvsp_message *nvmsg = hv_pkt_data(desc);
 
 	trace_nvsp_recv(ndev, channel, nvmsg);
@@ -1240,7 +1248,7 @@ static int netvsc_process_raw_pkt(struct hv_device *device,
 		break;
 
 	case VM_PKT_DATA_USING_XFER_PAGES:
-		return netvsc_receive(ndev, net_device, channel,
+		return netvsc_receive(ndev, net_device, nvchan,
 				      desc, nvmsg);
 		break;
 
@@ -1284,7 +1292,7 @@ int netvsc_poll(struct napi_struct *napi, int budget)
 		nvchan->desc = hv_pkt_iter_first(channel);
 
 	while (nvchan->desc && work_done < budget) {
-		work_done += netvsc_process_raw_pkt(device, channel, net_device,
+		work_done += netvsc_process_raw_pkt(device, nvchan, net_device,
 						    ndev, nvchan->desc, budget);
 		nvchan->desc = hv_pkt_iter_next(channel, nvchan->desc);
 	}