[PATCH v2 2/9] virtio_net: set up xdp for multi buffer packets

Heng Qi
2022-12-20T14:15:00Z

When the xdp program sets xdp.frags, which means it can process
multi-buffer packets over larger MTU, so we continue to support xdp.
But for single-buffer xdp, we should keep checking for MTU.

Signed-off-by: Heng Qi <hengqi@linux.alibaba.com>
Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
---
drivers/net/virtio_net.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 443aa7b8f0ad..c5c4e9db4ed3 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -3095,8 +3095,8 @@ static int virtnet_xdp_set(struct net_device *dev, struct bpf_prog *prog,
return -EINVAL;
}

- if (dev->mtu > max_sz) {
- NL_SET_ERR_MSG_MOD(extack, "MTU too large to enable XDP");
+ if (prog && !prog->aux->xdp_has_frags && dev->mtu > max_sz) {
+ NL_SET_ERR_MSG_MOD(extack, "MTU too large to enable XDP without frags");
netdev_warn(dev, "XDP requires MTU less than %lu\n", max_sz);
return -EINVAL;
}
--
2.19.1.6.gb485710b