virtio-net: disable the hole mechanism for xdp

XDP core assumes that the frame_size of xdp_buff and the length of
the frag are PAGE_SIZE. The hole may cause the processing of xdp to
fail, so we disable the hole mechanism when xdp is set.

Signed-off-by: Heng Qi <hengqi@linux.alibaba.com>
Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 7723b2a..a3271d2 100644 (file)
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -1426,8 +1426,11 @@ static int add_recvbuf_mergeable(struct virtnet_info *vi,
                /* To avoid internal fragmentation, if there is very likely not
                 * enough space for another buffer, add the remaining space to
                 * the current buffer.
+                * XDP core assumes that frame_size of xdp_buff and the length
+                * of the frag are PAGE_SIZE, so we disable the hole mechanism.
                 */
-               len += hole;
+               if (!headroom)
+                       len += hole;
                alloc_frag->offset += hole;
        }