1 files changed, 39 insertions, 5 deletions

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index ce37a7e9541c..0886b8a2d92d 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -55,6 +55,9 @@ struct virtnet_info
         struct tasklet_struct tasklet;
         bool free_in_tasklet;
 
+        /* I like... big packets and I cannot lie! */
+        bool big_packets;
+
         /* Receive & send queues. */
         struct sk_buff_head recv;
         struct sk_buff_head send;
@@ -89,6 +92,7 @@ static void receive_skb(struct net_device *dev, struct sk_buff *skb,
                         unsigned len)
 {
         struct virtio_net_hdr *hdr = skb_vnet_hdr(skb);
+        int err;
 
         if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) {
                 pr_debug("%s: short packet %i\n", dev->name, len);
@@ -96,10 +100,14 @@ static void receive_skb(struct net_device *dev, struct sk_buff *skb,
                 goto drop;
         }
         len -= sizeof(struct virtio_net_hdr);
-        BUG_ON(len > MAX_PACKET_LEN);
-
-        skb_trim(skb, len);
 
+        err = pskb_trim(skb, len);
+        if (err) {
+                pr_debug("%s: pskb_trim failed %i %d\n", dev->name, len, err);
+                dev->stats.rx_dropped++;
+                goto drop;
+        }
+        skb->truesize += skb->data_len;
         dev->stats.rx_bytes += skb->len;
         dev->stats.rx_packets++;
 
@@ -161,7 +169,7 @@ static void try_fill_recv(struct virtnet_info *vi)
 {
         struct sk_buff *skb;
         struct scatterlist sg[2+MAX_SKB_FRAGS];
-        int num, err;
+        int num, err, i;
 
         sg_init_table(sg, 2+MAX_SKB_FRAGS);
         for (;;) {
@@ -171,6 +179,24 @@ static void try_fill_recv(struct virtnet_info *vi)
 
                 skb_put(skb, MAX_PACKET_LEN);
                 vnet_hdr_to_sg(sg, skb);
+
+                if (vi->big_packets) {
+                        for (i = 0; i < MAX_SKB_FRAGS; i++) {
+                                skb_frag_t *f = &skb_shinfo(skb)->frags[i];
+                                f->page = alloc_page(GFP_ATOMIC);
+                                if (!f->page)
+                                        break;
+
+                                f->page_offset = 0;
+                                f->size = PAGE_SIZE;
+
+                                skb->data_len += PAGE_SIZE;
+                                skb->len += PAGE_SIZE;
+
+                                skb_shinfo(skb)->nr_frags++;
+                        }
+                }
+
                 num = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1;
                 skb_queue_head(&vi->recv, skb);
 
@@ -485,6 +511,12 @@ static int virtnet_probe(struct virtio_device *vdev)
          * the timer. */
         vi->free_in_tasklet = virtio_has_feature(vdev,VIRTIO_F_NOTIFY_ON_EMPTY);
 
+        /* If we can receive ANY GSO packets, we must allocate large ones. */
+        if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4)
+            || virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6)
+            || virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN))
+                vi->big_packets = true;
+
         /* We expect two virtqueues, receive then send. */
         vi->rvq = vdev->config->find_vq(vdev, 0, skb_recv_done);
         if (IS_ERR(vi->rvq)) {
@@ -571,7 +603,9 @@ static unsigned int features[] = {
         VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM,
         VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC,
         VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6,
-        VIRTIO_NET_F_HOST_ECN, VIRTIO_F_NOTIFY_ON_EMPTY,
+        VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6,
+        VIRTIO_NET_F_GUEST_ECN, /* We don't yet handle UFO input. */
+        VIRTIO_F_NOTIFY_ON_EMPTY,
 };
 
 static struct virtio_driver virtio_net = {