[PATCH net-next v1 00/19] virtio-net: support AF_XDP zero copy

Jason Wang
Tue, 17 Oct 2023 02:53:44 -0000

On Mon, Oct 16, 2023 at 8:00?PM Xuan Zhuo <xuanzhuo at linux.alibaba.com>
wrote:
>
> ## AF_XDP
>
> XDP socket(AF_XDP) is an excellent bypass kernel network framework. The
zero
> copy feature of xsk (XDP socket) needs to be supported by the driver. The
> performance of zero copy is very good. mlx5 and intel ixgbe already support
> this feature, This patch set allows virtio-net to support xsk's
zerocopy xmit
> feature.
>
> At present, we have completed some preparation:
>
> 1. vq-reset (virtio spec and kernel code)
> 2. virtio-core premapped dma
> 3. virtio-net xdp refactor
>
> So it is time for Virtio-Net to complete the support for the XDP Socket
> Zerocopy.
>
> Virtio-net can not increase the queue num at will, so xsk shares the queue
with
> kernel.
>
> On the other hand, Virtio-Net does not support generate interrupt from
driver
> manually, so when we wakeup tx xmit, we used some tips. If the CPU run by
TX
> NAPI last time is other CPUs, use IPI to wake up NAPI on the remote CPU. If
it
> is also the local CPU, then we wake up napi directly.
>
> This patch set includes some refactor to the virtio-net to let that to
support
> AF_XDP.
>
> ## performance
>
> ENV: Qemu with vhost-user(polling mode).
>
> Sockperf: https://github.com/Mellanox/sockperf
> I use this tool to send udp packet by kernel syscall.
>
> xmit command: sockperf tp -i 10.0.3.1 -t 1000
>
> I write a tool that sends udp packets or recvs udp packets by AF_XDP.
>
>                   | Guest APP CPU |Guest Softirq CPU | UDP PPS
> ------------------|---------------|------------------|------------
> xmit by syscall   |   100%        |                  |   676,915
> xmit by xsk       |   59.1%       |   100%           | 5,447,168
> recv by syscall   |   60%         |   100%           |   932,288
> recv by xsk       |   35.7%       |   100%           | 3,343,168

Any chance we can get a testpmd result (which I guess should be better
than PPS above)?

Thanks

>
> ## maintain
>
> I am currently a reviewer for virtio-net. I commit to maintain AF_XDP
support in
> virtio-net.
>
> Please review.
>
> Thanks.
>
> v1:
>     1. remove two virtio commits. Push this patchset to net-next
>     2. squash "virtio_net: virtnet_poll_tx support rescheduled"
to xsk: support tx
>     3. fix some warnings
>
> Xuan Zhuo (19):
>   virtio_net: rename free_old_xmit_skbs to free_old_xmit
>   virtio_net: unify the code for recycling the xmit ptr
>   virtio_net: independent directory
>   virtio_net: move to virtio_net.h
>   virtio_net: add prefix virtnet to all struct/api inside virtio_net.h
>   virtio_net: separate virtnet_rx_resize()
>   virtio_net: separate virtnet_tx_resize()
>   virtio_net: sq support premapped mode
>   virtio_net: xsk: bind/unbind xsk
>   virtio_net: xsk: prevent disable tx napi
>   virtio_net: xsk: tx: support tx
>   virtio_net: xsk: tx: support wakeup
>   virtio_net: xsk: tx: virtnet_free_old_xmit() distinguishes xsk buffer
>   virtio_net: xsk: tx: virtnet_sq_free_unused_buf() check xsk buffer
>   virtio_net: xsk: rx: introduce add_recvbuf_xsk()
>   virtio_net: xsk: rx: introduce receive_xsk() to recv xsk buffer
>   virtio_net: xsk: rx: virtnet_rq_free_unused_buf() check xsk buffer
>   virtio_net: update tx timeout record
>   virtio_net: xdp_features add NETDEV_XDP_ACT_XSK_ZEROCOPY
>
>  MAINTAINERS                                 |   2 +-
>  drivers/net/Kconfig                         |   8 +-
>  drivers/net/Makefile                        |   2 +-
>  drivers/net/virtio/Kconfig                  |  13 +
>  drivers/net/virtio/Makefile                 |   8 +
>  drivers/net/{virtio_net.c => virtio/main.c} | 652 +++++++++-----------
>  drivers/net/virtio/virtio_net.h             | 359 +++++++++++
>  drivers/net/virtio/xsk.c                    | 545 ++++++++++++++++
>  drivers/net/virtio/xsk.h                    |  32 +
>  9 files changed, 1247 insertions(+), 374 deletions(-)
>  create mode 100644 drivers/net/virtio/Kconfig
>  create mode 100644 drivers/net/virtio/Makefile
>  rename drivers/net/{virtio_net.c => virtio/main.c} (91%)
>  create mode 100644 drivers/net/virtio/virtio_net.h
>  create mode 100644 drivers/net/virtio/xsk.c
>  create mode 100644 drivers/net/virtio/xsk.h
>
> --
> 2.32.0.3.g01195cf9f
>