On Tue, 2024-01-16 at 14:28 +0800, Xuan Zhuo wrote: > This is first part of virtio-net support AF_XDP zero copy. For future submissions, unless explcitly requested otherwise, please wait for a series being processed before posting the follow-ups. Otherwise any change requested to earlier patches could possibly/likely need changing (and reposting) all the following. > > The whole patch set > http://lore.kernel.org/all/20231229073108.57778-1-xuanzhuo@xxxxxxxxxxxxxxxxx > > > ## 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: 5959955552 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. ## 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
