Re: [PATCH 00/24] Support VIRTIO_F_RING_RESET for virtio-net, vhost-user, vhost-kernel in virtio pci-modern

[Jason Wang]

在 2022/8/16 09:06, Kangjie Xu 写道:
> The virtio queue reset function has already been defined in the virtio spec 1.2.
> The relevant virtio spec information is here:
>
>      https://github.com/oasis-tcs/virtio-spec/issues/124
>      https://github.com/oasis-tcs/virtio-spec/issues/139
>
> This patch set is to support this function in QEMU. It consists of several 
> parts:
> 1. Patches 1-7 are the basic interfaces for vq reset in virtio and virtio-pci.
> 2. Patches 8-12 support vq stop and vq restart for vhost-kernel.
> 3. Patches 13-19 support vq stop and vq restart for vhost-user.
> 4. Patches 20-22 support vq reset and re-enable for virtio-net.
> 5. Patches 23-24 enable the vq reset feature for vhost-kernel and vhost-user.
>
> The process of virtqueue reset can be concluded as:
> 1. The virtqueue is disabled when VIRTIO_PCI_COMMON_Q_RESET is written.
> 2. Then the virtqueue can be optionally restarted(re-enabled).
>
> Since this patch set involves multiple modules and seems a bit messy, we 
> briefly describe the
> calling process for different modes below.
> virtio-net:
> 1. VIRTIO_PCI_COMMON_Q_RESET is written [virtio-pci]
>      -> virtio_queue_reset() [virtio]
>          -> virtio_net_queue_reset() [virtio-net]
>          -> __virtio_queue_reset()
> 2. VIRTIO_PCI_COMMON_Q_ENABLE is written [virtio-pci]
>      -> set enabled, reset status of vq.
>
> vhost-kernel:
> 1. VIRTIO_PCI_COMMON_Q_RESET is written [virtio-pci]
>      -> virtio_queue_reset() [virtio]
>          -> virtio_net_queue_reset() [virtio-net]
>              -> vhost_net_virtqueue_stop() [vhost-net]
>                  -> vhost_net_set_backend() [vhost]
>                  -> vhost_dev_virtqueue_stop()
>                      -> vhost_virtqueue_unmap()
>          -> __virtio_queue_reset()
> 2. VIRTIO_PCI_COMMON_Q_ENABLE is written [virtio-pci]
>      -> virtio_queue_enable() [virtio]
>          -> virtio_net_queue_enable() [virtio-net]
>              -> vhost_net_virtqueue_restart() [vhost-net]
>                  -> vhost_dev_virtqueue_restart() [vhost]
>                      -> vhost_virtqueue_start()
>                  -> vhost_net_set_backend()
>      -> set enabled, reset status of vq.
>
> vhost-user:
> 1. VIRTIO_PCI_COMMON_Q_RESET is written [virtio-pci]
>      -> virtio_queue_reset() [virtio]
>          -> virtio_net_queue_reset() [virtio-net]
>              -> vhost_net_virtqueue_stop() [vhost-net]
>                  -> vhost_dev_virtqueue_stop() [vhost]
>                      -> vhost_user_reset_vring() [vhost-user]
>                          -> send VHOST_USER_RESET_VRING to the device
>                      -> vhost_virtqueue_unmap()
>          -> __virtio_queue_reset()
> 2. VIRTIO_PCI_COMMON_Q_ENABLE is written [virtio-pci]
>      -> virtio_queue_enable() [virtio]
>          -> virtio_net_queue_enable() [virtio-net]
>              -> vhost_net_virtqueue_restart() [vhost-net]
>                  -> vhost_dev_virtqueue_restart() [vhost]
>                      -> vhost_virtqueue_start()
>                      -> vhost_user_set_single_vring_enable [vhost-user]
>                          -> send VHOST_USER_SET_VRING_ENABLE to the device
>      -> set enabled, reset status of vq.
>
>
> Test environment:
>      Host: 5.19.0-rc3 (With vq reset support)
>      Qemu: QEMU emulator version 7.0.50
>      Guest: 5.19.0-rc3 (With vq reset support)
>      DPDK: 22.07-rc1 (With vq reset support)
>      Test Cmd: ethtool -g eth1; ethtool -G eth1 rx $1 tx $2; ethtool -g eth1;
>
>      The drvier can resize the virtio queue, then virtio queue reset function 
> should
>      be triggered.
>
>      The default is split mode, modify Qemu virtio-net to add PACKED feature to
>      test packed mode.
>
> Guest Kernel Patch:
>      
> https://lore.kernel.org/bpf/20220801063902.129329-1-xuanzhuo@linux.alibaba.com/
>
> DPDK Patch:
>      
> https://github.com/middaywords/dpdk/compare/72206323a5dd3182b13f61b25a64abdddfee595c...eabadfac7953da66bc10ffb8284b490d09bb7ec7
>
> Host Kernel Patch:
>      
> https://github.com/middaywords/linux/commit/19a91e0d7167b2031e46078c6215c213b89cb2c3
>
> Looking forward to your review and comments. Thanks.


I suggest to split vhost-user part into another series since:

1) vhost-net kernel is ready for this future

2) vhost-user probably requires some extensions of the current protocol

Then it can speed up the merging and reduce the rebasing of a huge series.

Thanks


> Kangjie Xu (19):
>    virtio: introduce virtio_queue_enable()
>    virtio: core: vq reset feature negotation support
>    virtio-pci: support queue enable
>    vhost: extract the logic of unmapping the vrings and desc
>    vhost: introduce vhost_dev_virtqueue_stop()
>    vhost: introduce vhost_dev_virtqueue_restart()
>    vhost-net: vhost-kernel: introduce vhost_net_virtqueue_stop()
>    vhost-net: vhost-kernel: introduce vhost_net_virtqueue_restart()
>    docs: vhost-user: add VHOST_USER_RESET_VRING message
>    vhost-user: introduce vhost_reset_vring() interface
>    vhost-user: add op to enable or disable a single vring
>    vhost: vhost-user: update vhost_dev_virtqueue_stop()
>    vhost: vhost-user: update vhost_dev_virtqueue_restart()
>    vhost-net: vhost-user: update vhost_net_virtqueue_stop()
>    vhost-net: vhost-user: update vhost_net_virtqueue_restart()
>    virtio-net: introduce flush_or_purge_queued_packets()
>    virtio-net: support queue_enable
>    vhost: vhost-kernel: enable vq reset feature
>    vhost: vhost-user: enable vq reset feature
>
> Xuan Zhuo (5):
>    virtio: sync relevant definitions with linux
>    virtio: introduce __virtio_queue_reset()
>    virtio: introduce virtio_queue_reset()
>    virtio-pci: support queue reset
>    virtio-net: support queue reset
>
>   docs/interop/vhost-user.rst                   | 10 +++
>   hw/core/machine.c                             |  1 +
>   hw/net/vhost_net.c                            | 79 +++++++++++++++++++
>   hw/net/virtio-net.c                           | 58 ++++++++++++--
>   hw/virtio/vhost-user.c                        | 67 ++++++++++++++--
>   hw/virtio/vhost.c                             | 79 +++++++++++++++++--
>   hw/virtio/virtio-pci.c                        | 20 +++++
>   hw/virtio/virtio.c                            | 62 +++++++++++----
>   include/hw/virtio/vhost-backend.h             |  6 ++
>   include/hw/virtio/vhost.h                     |  5 ++
>   include/hw/virtio/virtio-pci.h                |  1 +
>   include/hw/virtio/virtio.h                    |  8 +-
>   include/net/vhost_net.h                       |  4 +
>   .../standard-headers/linux/virtio_config.h    |  5 ++
>   include/standard-headers/linux/virtio_pci.h   |  2 +
>   15 files changed, 371 insertions(+), 36 deletions(-)