Resending, email didn't reach the list (used wrong sender email)
On Tue, 20 Sep 2016 10:29:43 +0200 Jesper Dangaard Brouer <net...@brouer.com>
wrote:
> On Mon, 19 Sep 2016 16:58:58 +0300 Tariq Toukan <tar...@mellanox.com> wrote:
>
> > + act = bpf_prog_run_xdp(prog, &xdp);
> > + switch (act) {
> > + case XDP_PASS:
> > + return false;
> > + case XDP_TX:
> > + consumed = mlx5e_xmit_xdp_frame(&rq->channel->xdp_sq, di,
> > + MLX5_RX_HEADROOM,
> > + len);
> > + rq->stats.xdp_tx += consumed;
> > + return consumed;
> > + default:
> > + bpf_warn_invalid_xdp_action(act);
> > + return false;
>
> This looks wrong. According to the specification[1] and comment in the
> code /include/uapi/linux/bpf.h: "Unknown return codes will result in
> packet drop"
>
> > + case XDP_ABORTED:
>
> It is not clearly defined, but I believe XDP_ABORTED should also result
> in a warning (calling bpf_warn_invalid_xdp_action(act)).
>
>
> > + case XDP_DROP:
> > + rq->stats.xdp_drop++;
> > + mlx5e_page_release(rq, di, true);
> > + return true;
> > + }
>
>
> I've started documenting XDP[2], as this patch clearly shows there is a
> need to have a specification, given already the second driver
> supporting XDP gets these details wrong.
>
> [1]
> https://prototype-kernel.readthedocs.io/en/latest/networking/XDP/implementation/xdp_actions.html#xdp-aborted
>
> [2]
> https://prototype-kernel.readthedocs.io/en/latest/networking/XDP/index.html
>
--
Best regards,
Jesper Dangaard Brouer
MSc.CS, Principal Kernel Engineer at Red Hat
Author of http://www.iptv-analyzer.org
LinkedIn: http://www.linkedin.com/in/brouer
