drivers/virtio: Add support for IPv4/TSO

When the host indicates support for TSO, enable it and accept large
packets when the corresponding uknetbuf flag is set.

Signed-off-by: Marco Schlumpp <marco@unikraft.io>

diff --git a/plat/drivers/virtio/virtio_net.c b/plat/drivers/virtio/virtio_net.c
index fb0e6b4134776e7f944c24d1d8193415f069e77a..ab93f79a1f2b06db33ad503b6432aa5f1ee91221 100644 (file)
--- a/plat/drivers/virtio/virtio_net.c
+++ b/plat/drivers/virtio/virtio_net.c
@@ -385,7 +385,11 @@ static int virtio_netdev_xmit(struct uk_netdev *dev,
                vhdr->csum_start   = pkt->csum_start - header_sz;
                vhdr->csum_offset  = pkt->csum_offset;
        }
-       vhdr->gso_type = VIRTIO_NET_HDR_GSO_NONE;
+       if (pkt->flags & UK_NETBUF_F_GSO_TCPV4) {
+               vhdr->gso_type     = VIRTIO_NET_HDR_GSO_TCPV4;
+               vhdr->hdr_len      = pkt->header_len;
+               vhdr->gso_size     = pkt->gso_size;
+       }
 
        /**
         * Prepare the sglist and enqueue the buffer to the virtio-ring.
@@ -413,17 +417,19 @@ static int virtio_netdev_xmit(struct uk_netdev *dev,
        if (pkt->next) {
                rc = uk_sglist_append_netbuf(&queue->sg, pkt->next);
                if (unlikely(rc != 0)) {
-                       uk_pr_err("Failed to append to the sg list\n");
+                       uk_pr_err("Failed to append to the sg list: %d\n", rc);
                        goto err_remove_vhdr;
                }
        }
 
-       total_len = uk_sglist_length(&queue->sg);
-       if (unlikely(total_len > VIRTIO_PKT_BUFFER_LEN)) {
-               uk_pr_err("Packet size too big: %lu, max:%u\n",
-                         total_len, VIRTIO_PKT_BUFFER_LEN);
-               rc = -ENOTSUP;
-               goto err_remove_vhdr;
+       if (!(pkt->flags & UK_NETBUF_F_GSO_TCPV4)) {
+               total_len = uk_sglist_length(&queue->sg);
+               if (unlikely(total_len > VIRTIO_PKT_BUFFER_LEN)) {
+                       uk_pr_err("Packet size too big: %lu, max:%u\n",
+                                 total_len, VIRTIO_PKT_BUFFER_LEN);
+                       rc = -ENOTSUP;
+                       goto err_remove_vhdr;
+               }
        }
 
        /**
@@ -922,6 +928,16 @@ static int virtio_netdev_feature_negotiate(struct uk_netdev *n)
                VIRTIO_FEATURE_SET(drv_features, VIRTIO_NET_F_GUEST_CSUM);
        }
 
+       /**
+        * TCP Segmentation Offload
+        * NOTE: This enables sending and receiving of packets marked with
+        *       VIRTIO_NET_HDR_GSO_TCPV4
+        */
+       if (VIRTIO_FEATURE_HAS(host_features, VIRTIO_NET_F_GSO))
+               VIRTIO_FEATURE_SET(drv_features, VIRTIO_NET_F_GSO);
+       if (VIRTIO_FEATURE_HAS(host_features, VIRTIO_NET_F_HOST_TSO4))
+               VIRTIO_FEATURE_SET(drv_features, VIRTIO_NET_F_HOST_TSO4);
+
        /**
         * Announce our enabled driver features back to the backend device
         */
@@ -1119,9 +1135,15 @@ static void virtio_net_info_get(struct uk_netdev *dev,
        dev_info->nb_encap_tx = sizeof(struct virtio_net_hdr_padded);
        dev_info->nb_encap_rx = sizeof(struct virtio_net_hdr_padded);
        dev_info->ioalign = sizeof(void *); /* word size alignment */
+
        dev_info->features = UK_NETDEV_F_RXQ_INTR
                | (VIRTIO_FEATURE_HAS(vndev->vdev->features, VIRTIO_NET_F_CSUM)
-                  ? UK_NETDEV_F_PARTIAL_CSUM : 0);
+                  ? UK_NETDEV_F_PARTIAL_CSUM : 0)
+               | ((VIRTIO_FEATURE_HAS(vndev->vdev->features,
+                                      VIRTIO_NET_F_HOST_TSO4)
+                   || VIRTIO_FEATURE_HAS(vndev->vdev->features,
+                                         VIRTIO_NET_F_GSO))
+                  ? UK_NETDEV_F_TSO4 : 0);
 }
 
 static int virtio_net_start(struct uk_netdev *n)