On Tue, Jun 3, 2025 at 11:07 PM Bui Quang Minh <minhquangbui99@xxxxxxxxx> wrote:
>
> 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. This commit instead returns
> XDP_DROP in that case.
>
> Fixes: 99c861b44eb1 ("virtio_net: xsk: rx: support recv merge mode")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Bui Quang Minh <minhquangbui99@xxxxxxxxx>
> ---
> 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 e53ba600605a..4c35324d6e5b 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -1309,9 +1309,14 @@ static struct sk_buff *virtnet_receive_xsk_merge(struct net_device *dev, struct
> ret = XDP_PASS;
It would be simpler to just assign XDP_DROP here?
Or if you wish to stick to the way, we can simply remove this assignment.
> 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_DROP;
> + }
> rcu_read_unlock();
>
> switch (ret) {
> --
> 2.43.0
>
Thanks
