| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <aWpPk6PrHuL+zdMr@lizhi-Precision-Tower-5810>
Date: Fri, 16 Jan 2026 09:47:47 -0500
From: Frank Li <Frank.li@....com>
To: Wei Fang <wei.fang@....com>
Cc: shenwei.wang@....com, xiaoning.wang@....com, andrew+netdev@...n.ch,
davem@...emloft.net, edumazet@...gle.com, kuba@...nel.org,
pabeni@...hat.com, ast@...nel.org, daniel@...earbox.net,
hawk@...nel.org, john.fastabend@...il.com, sdf@...ichev.me,
netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
imx@...ts.linux.dev, bpf@...r.kernel.org
Subject: Re: [PATCH v2 net-next 14/14] net: fec: add AF_XDP zero-copy support
On Fri, Jan 16, 2026 at 03:40:27PM +0800, Wei Fang wrote:
> Add AF_XDP zero-copy support for both TX and RX.
>
> For RX, instead of allocating buffers from the page pool, the buffers
> are allocated from xsk pool, so fec_alloc_rxq_buffers_zc() is added to
> allocate RX buffers from xsk pool. And fec_enet_rx_queue_xsk() is used
> to process the frames from the RX queue which is bound to the AF_XDP
> socket. Similar to the XDP copy mode, the zero-copy mode also supports
> XDP_TX, XDP_PASS, XDP_DROP and XDP_REDIRECT actions. In addition,
> fec_enet_xsk_tx_xmit() is similar to fec_enet_xdp_tx_xmit() and is used
> to handle XDP_TX action in zero-copy mode.
>
> For TX, there are two cases, one is the frames from the AF_XDP socket,
> so fec_enet_xsk_xmit() is added to directly transmit the frames from
> the socket and the buffer type is marked as FEC_TXBUF_T_XSK_XMIT. The
> other one is the frams from the RX queue (XDP_TX action), the buffer
> type is marked as FEC_TXBUF_T_XSK_TX. Therefore, fec_enet_tx_queue()
> could correctly clean the TX queue base on the buffer type.
>
> Also, some tests have been done on the i.MX93-EVK board with the xdpsock
> tool, the following are the results.
>
> Env: i.MX93 connects to a packet generator, the link speed is 1Gbps, and
> flow-control is off. The RX packet size is 64 bytes including FCS. Only
> one RX queue (CPU) is used to receive frames.
>
> 1. MAC swap L2 forwarding
> 1.1 Zero-copy mode
> root@...93evk:~# ./xdpsock -i eth0 -l -z
> sock0@...0:0 l2fwd xdp-drv
> pps pkts 1.00
> rx 414715 415455
> tx 414715 415455
>
> 1.2 Copy mode
> root@...93evk:~# ./xdpsock -i eth0 -l -c
> sock0@...0:0 l2fwd xdp-drv
> pps pkts 1.00
> rx 356396 356609
> tx 356396 356609
>
> 2. TX only
> 2.1 Zero-copy mode
> root@...93evk:~# ./xdpsock -i eth0 -t -s 64 -z
> sock0@...0:0 txonly xdp-drv
> pps pkts 1.00
> rx 0 0
> tx 1119573 1126720
>
> 2.2 Copy mode
> root@...93evk:~# ./xdpsock -i eth0 -t -s 64 -c
> sock0@...0:0 txonly xdp-drv
> pps pkts 1.00
> rx 0 0
> tx 406864 407616
>
> Signed-off-by: Wei Fang <wei.fang@....com>
> ---
> drivers/net/ethernet/freescale/fec.h | 13 +-
> drivers/net/ethernet/freescale/fec_main.c | 611 ++++++++++++++++++++--
> 2 files changed, 582 insertions(+), 42 deletions(-)
>
> diff --git a/drivers/net/ethernet/freescale/fec.h b/drivers/net/ethernet/freescale/fec.h
> index ad7aba1a8536..7176803146f3 100644
> --- a/drivers/net/ethernet/freescale/fec.h
> +++ b/drivers/net/ethernet/freescale/fec.h
...
> static int fec_enet_bpf(struct net_device *dev, struct netdev_bpf *bpf)
> {
> struct fec_enet_private *fep = netdev_priv(dev);
> bool is_run = netif_running(dev);
> struct bpf_prog *old_prog;
>
> + /* No need to support the SoCs that require to do the frame swap
> + * because the performance wouldn't be better than the skb mode.
> + */
> + if (fep->quirks & FEC_QUIRK_SWAP_FRAME)
> + return -EOPNOTSUPP;
> +
> switch (bpf->command) {
> case XDP_SETUP_PROG:
> - /* No need to support the SoCs that require to
> - * do the frame swap because the performance wouldn't be
> - * better than the skb mode.
> - */
> - if (fep->quirks & FEC_QUIRK_SWAP_FRAME)
> - return -EOPNOTSUPP;
> -
This part can be new patch.
Code itself look good, but I am not familar XDP's logic.
Frank
> if (!bpf->prog)
> xdp_features_clear_redirect_target(dev);
>
> @@ -3994,7 +4497,8 @@ static int fec_enet_bpf(struct net_device *dev, struct netdev_bpf *bpf)
> return 0;
>
> case XDP_SETUP_XSK_POOL:
> - return -EOPNOTSUPP;
> + return fec_setup_xsk_pool(dev, bpf->xsk.pool,
> + bpf->xsk.queue_id);
>
> default:
> return -EOPNOTSUPP;
> @@ -4143,6 +4647,29 @@ static int fec_enet_xdp_xmit(struct net_device *dev,
> return sent_frames;
> }
>
> +static int fec_enet_xsk_wakeup(struct net_device *ndev, u32 queue, u32 flags)
> +{
> + struct fec_enet_private *fep = netdev_priv(ndev);
> + struct fec_enet_priv_rx_q *rxq;
> +
> + if (!netif_running(ndev) || !netif_carrier_ok(ndev))
> + return -ENETDOWN;
> +
> + if (queue >= fep->num_rx_queues || queue >= fep->num_tx_queues)
> + return -ERANGE;
> +
> + rxq = fep->rx_queue[queue];
> + if (!rxq->xsk_pool)
> + return -EINVAL;
> +
> + if (!napi_if_scheduled_mark_missed(&fep->napi)) {
> + if (likely(napi_schedule_prep(&fep->napi)))
> + __napi_schedule(&fep->napi);
> + }
> +
> + return 0;
> +}
> +
> static int fec_hwtstamp_get(struct net_device *ndev,
> struct kernel_hwtstamp_config *config)
> {
> @@ -4205,6 +4732,7 @@ static const struct net_device_ops fec_netdev_ops = {
> .ndo_set_features = fec_set_features,
> .ndo_bpf = fec_enet_bpf,
> .ndo_xdp_xmit = fec_enet_xdp_xmit,
> + .ndo_xsk_wakeup = fec_enet_xsk_wakeup,
> .ndo_hwtstamp_get = fec_hwtstamp_get,
> .ndo_hwtstamp_set = fec_hwtstamp_set,
> };
> @@ -4332,7 +4860,8 @@ static int fec_enet_init(struct net_device *ndev)
>
> if (!(fep->quirks & FEC_QUIRK_SWAP_FRAME))
> ndev->xdp_features = NETDEV_XDP_ACT_BASIC |
> - NETDEV_XDP_ACT_REDIRECT;
> + NETDEV_XDP_ACT_REDIRECT |
> + NETDEV_XDP_ACT_XSK_ZEROCOPY;
>
> fec_restart(ndev);
>
> --
> 2.34.1
>
Powered by blists - more mailing lists