## 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 ## maintain I am currently a reviewer for virtio-net. I commit to maintain AF_XDP support in virtio-net. Please review. Thanks. Xuan Zhuo (22): virtio_ring: virtqueue_set_dma_premapped support disable virtio_ring: introduce virtqueue_dma_[un]map_page_attrs 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: virtnet_poll_tx support rescheduled 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} | 644 +++++++++----------- drivers/net/virtio/virtio_net.h | 360 +++++++++++ drivers/net/virtio/xsk.c | 545 +++++++++++++++++ drivers/net/virtio/xsk.h | 32 + drivers/virtio/virtio_ring.c | 63 +- include/linux/virtio.h | 9 +- 11 files changed, 1315 insertions(+), 371 deletions(-) create mode 100644 drivers/net/virtio/Kconfig create mode 100644 drivers/net/virtio/Makefile rename drivers/net/{virtio_net.c => virtio/main.c} (92%) 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
