Re: [PATCH net-next] net: mlx4: Add support for XDP_REDIRECT

Re: [PATCH net-next] net: mlx4: Add support for XDP_REDIRECT

[Joshua Roys]

Adding requested maintainers to CC.

On Thu, Sep 23, 2021 at 12:11 PM Joshua Roys <roysjosh@gmail.com> wrote:
>
> Signed-off-by: Joshua Roys <roysjosh@gmail.com>
> ---
>  drivers/net/ethernet/mellanox/mlx4/en_rx.c | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
>
> This is a pattern-match commit, based off of the mlx4 XDP_TX and other
> drivers' XDP_REDIRECT enablement patches. The goal was to get AF_XDP
> working in VPP and this was successful. Tested with a CX3.
>
> diff --git a/drivers/net/ethernet/mellanox/mlx4/en_rx.c b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
> index 7f6d3b82c29b..557d7daac2d3 100644
> --- a/drivers/net/ethernet/mellanox/mlx4/en_rx.c
> +++ b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
> @@ -669,6 +669,7 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
>         struct bpf_prog *xdp_prog;
>         int cq_ring = cq->ring;
>         bool doorbell_pending;
> +       bool xdp_redir_flush;
>         struct mlx4_cqe *cqe;
>         struct xdp_buff xdp;
>         int polled = 0;
> @@ -682,6 +683,7 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
>         xdp_prog = rcu_dereference_bh(ring->xdp_prog);
>         xdp_init_buff(&xdp, priv->frag_info[0].frag_stride, &ring->xdp_rxq);
>         doorbell_pending = false;
> +       xdp_redir_flush = false;
>
>         /* We assume a 1:1 mapping between CQEs and Rx descriptors, so Rx
>          * descriptor offset can be deduced from the CQE index instead of
> @@ -790,6 +792,14 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
>                         switch (act) {
>                         case XDP_PASS:
>                                 break;
> +                       case XDP_REDIRECT:
> +                               if (xdp_do_redirect(dev, &xdp, xdp_prog) >= 0) {
> +                                       xdp_redir_flush = true;
> +                                       frags[0].page = NULL;
> +                                       goto next;
> +                               }
> +                               trace_xdp_exception(dev, xdp_prog, act);
> +                               goto xdp_drop_no_cnt;
>                         case XDP_TX:
>                                 if (likely(!mlx4_en_xmit_frame(ring, frags, priv,
>                                                         length, cq_ring,
> @@ -897,6 +907,9 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
>                         break;
>         }
>
> +       if (xdp_redir_flush)
> +               xdp_do_flush();
> +
>         if (likely(polled)) {
>                 if (doorbell_pending) {
>                         priv->tx_cq[TX_XDP][cq_ring]->xdp_busy = true;
> --
> 2.31.1
>