On Tue, 2024-01-16 at 17:42 +0800, Xuan Zhuo wrote:
> This is the third part of virtio-net support AF_XDP zero copy.
>
> The whole patch set
> http://lore.kernel.org/all/20231229073108.57778-1-xuanz...@linux.alibaba.com
>
> ## 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).
> Host CPU: Intel(R) Xeon(R) Platinum 8163 CPU @ 2.50GHz
>
> ### virtio PMD in guest with testpmd
>
> testpmd> show port stats all
>
> NIC statistics for port 0
> RX-packets: 19531092064 RX-missed: 0 RX-bytes: 1093741155584
> RX-errors: 0
> RX-nombuf: 0
> TX-packets: 595992 TX-errors: 0 TX-bytes: 371030645664
>
>
> Throughput (since last show)
> Rx-pps: 8861574 Rx-bps: 3969985208
> Tx-pps: 8861493 Tx-bps: 3969962736
>
>
> ### AF_XDP PMD in guest with testpmd
>
> testpmd> show port stats all
>
> NIC statistics for port 0
> RX-packets: 68152727 RX-missed: 0 RX-bytes: 3816552712
> RX-errors: 0
> RX-nombuf: 0
> TX-packets: 68114967 TX-errors: 33216 TX-bytes: 3814438152
>
> Throughput (since last show)
> Rx-pps: 6333196 Rx-bps: 2837272088
> Tx-pps: 6333227 Tx-bps: 2837285936
>
>
> But AF_XDP consumes more CPU for tx and rx napi(100% and 86%).
>
> ## maintain
>
> I am currently a reviewer for virtio-net. I commit to maintain AF_XDP support
> in
> virtio-net.
>
> Please review.
>
> Thanks.
For future submission it would be better if you split this series in
smaller chunks: the maximum size allowed is 15 patches.
## Form letter - net-next-closed
The merge window for v6.8 has begun and we have already posted our pull
request. Therefore net-next is closed for new drivers, features, code
refactoring and optimizations. We are currently accepting bug fixes
only.
Please repost when net-next reopens after January 22nd.
RFC patches sent for review only are obviously welcome at any time.
See:
https://www.kernel.org/doc/html/next/process/maintainer-netdev.html#development-cycle
--
pw-bot: defer
