On 2018/09/10 17:24, Ilias Apalodimas wrote:
> Add basic AF_XDP support without zero-copy
>
> Signed-off-by: Ilias Apalodimas <ilias.apalodi...@linaro.org>
> ---
...
> @@ -707,6 +731,26 @@ static int netsec_process_rx(struct netsec_priv *priv,
> int budget)
> if (unlikely(!buf_addr))
> break;
>
> + if (xdp_prog) {
> + xdp_result = netsec_run_xdp(desc, priv, xdp_prog,
> + pkt_len);
> + if (xdp_result != NETSEC_XDP_PASS) {
> + xdp_flush |= xdp_result & NETSEC_XDP_REDIR;
> +
> + dma_unmap_single_attrs(priv->dev,
> + desc->dma_addr,
> + desc->len, DMA_TO_DEVICE,
> + DMA_ATTR_SKIP_CPU_SYNC);
> +
> + desc->len = desc_len;
> + desc->dma_addr = dma_handle;
> + desc->addr = buf_addr;
> + netsec_rx_fill(priv, idx, 1);
> + nsetsec_adv_desc(&dring->tail);
> + }
> + continue;
Continue even on XDP_PASS? Is this really correct?
Also seems there is no handling of adjust_head/tail for XDP_PASS case.
> + }
> +
> skb = build_skb(desc->addr, desc->len);
> if (unlikely(!skb)) {
> dma_unmap_single(priv->dev, dma_handle, desc_len,
> @@ -740,6 +784,9 @@ static int netsec_process_rx(struct netsec_priv *priv,
> int budget)
> nsetsec_adv_desc(&dring->tail);
> }
>
> + if (xdp_flush & NETSEC_XDP_REDIR)
> + xdp_do_flush_map();
> +
> return done;
> }
...
> +static u32 netsec_run_xdp(struct netsec_desc *desc, struct netsec_priv *priv,
> + struct bpf_prog *prog, u16 len)
> +
> +{
> + struct netsec_desc_ring *dring = &priv->desc_ring[NETSEC_RING_RX];
> + struct xdp_buff xdp;
> + u32 ret = NETSEC_XDP_PASS;
> + int err;
> + u32 act;
> +
> + xdp.data_hard_start = desc->addr;
> + xdp.data = desc->addr;
There is no headroom. REDIRECT using devmap/cpumap will fail due to
this. Generally we need XDP_PACKET_HEADROOM.
> + xdp_set_data_meta_invalid(&xdp);
> + xdp.data_end = xdp.data + len;
> + xdp.rxq = &dring->xdp_rxq;
> +
> + rcu_read_lock();
> + act = bpf_prog_run_xdp(prog, &xdp);
> +
> + switch (act) {
> + case XDP_PASS:
> + ret = NETSEC_XDP_PASS;
> + break;
> + case XDP_TX:
> + ret = netsec_xmit_xdp(priv, &xdp, desc);
> + break;
> + case XDP_REDIRECT:
> + err = xdp_do_redirect(priv->ndev, &xdp, prog);
> + if (!err) {
> + ret = NETSEC_XDP_REDIR;
> + } else {
> + ret = NETSEC_XDP_CONSUMED;
> + xdp_return_buff(&xdp);
> + }
> + break;
> + default:
> + bpf_warn_invalid_xdp_action(act);
> + /* fall through */
> + case XDP_ABORTED:
> + trace_xdp_exception(priv->ndev, prog, act);
> + /* fall through -- handle aborts by dropping packet */
> + case XDP_DROP:
> + ret = NETSEC_XDP_CONSUMED;
> + break;
> + }
> +
> + rcu_read_unlock();
> +
> + return ret;
> +}
> +
> +static int netsec_xdp_setup(struct netsec_priv *priv, struct bpf_prog *prog)
> +{
> + struct net_device *dev = priv->ndev;
> + struct bpf_prog *old_prog;
> +
> + /* For now just support only the usual MTU sized frames */
> + if (prog && dev->mtu > 1500) {
> + netdev_warn(dev, "Jumbo frames not yet supported with XDP\n");
Why not using extack?
> + return -EOPNOTSUPP;
> + }
> +
--
Toshiaki Makita
