Re: [PATCH net] virtio-net: drop the multi-buffer XDP packet in zerocopy
From: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Date: 2025-06-13 01:51:23
Also in:
bpf, lkml, stable, virtualization
On Tue, 3 Jun 2025 22:06:13 +0700, Bui Quang Minh [off-list ref] 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@vger.kernel.org
Signed-off-by: Bui Quang Minh <redacted>Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
quoted hunk ↗ jump to hunk
--- 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; 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