On Tue, 17 Oct 2023 10:53:44 +0800, Jason Wang <[email protected]> wrote:
> On Mon, Oct 16, 2023 at 8:00 PM Xuan Zhuo <[email protected]> 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)?
Do you mean testpmd + DPDK + AF_XDP?
Yes. This is probably better because my tool does more work. That is not a
complete testing tool used by our business.
What I noticed is that the hotspot is the driver writing virtio desc. Because
the device is in busy mode. So there is race between driver and device.
So I modified the virtio core and lazily updated avail idx. Then pps can reach
10,000,000.
Thanks.
>
> 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
> >
>
_______________________________________________
Virtualization mailing list
[email protected]
https://lists.linuxfoundation.org/mailman/listinfo/virtualization
