In virtio-net, we have not yet supported multi-buffer XDP packet in zerocopy mode when there is a binding XDP program. However, in that case, when receiving multi-buffer XDP packet, we skip the XDP program and return XDP_PASS. As a result, the packet is passed to normal network stack which is an incorrect behavior (e.g. a XDP program for packet count is installed, multi-buffer XDP packet arrives and does go through XDP program. As a result, the packet count does not increase but the packet is still received from network stack).This commit instead returns XDP_ABORTED in that case.

Fixes: 99c861b44eb1 ("virtio_net: xsk: rx: support recv merge mode") Cc: stable@vger.kernel.org Acked-by: Jason Wang jasowang@redhat.com Reviewed-by: Xuan Zhuo xuanzhuo@linux.alibaba.com Signed-off-by: Bui Quang Minh minhquangbui99@gmail.com --- Changes in v2: - Return XDP_ABORTED instead of XDP_DROP, make clearer explanation in commit message --- drivers/net/virtio_net.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index a757cbcab87f..8e8a179aaa49 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -1379,9 +1379,14 @@ static struct sk_buff *virtnet_receive_xsk_merge(struct net_device *dev, struct ret = XDP_PASS; rcu_read_lock(); prog = rcu_dereference(rq->xdp_prog); - /* TODO: support multi buffer. */ - if (prog && num_buf == 1) - ret = virtnet_xdp_handler(prog, xdp, dev, xdp_xmit, stats); + if (prog) { + /* TODO: support multi buffer. */ + if (num_buf == 1) + ret = virtnet_xdp_handler(prog, xdp, dev, xdp_xmit, + stats); + else + ret = XDP_ABORTED; + } rcu_read_unlock();

switch (ret) {