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

[Xuan Zhuo]

On Tue, 16 Aug 2022 02:14:10 -0400, "Michael S. Tsirkin" <mst@redhat.com> wrote:
> On Tue, Aug 16, 2022 at 09:06:12AM +0800, Kangjie Xu wrote:
> > 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.
>
> legacy mode testing?


legacy does not support vq reset.

Thanks.

>
> > 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.
> >
> > 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(-)
> >
> > --
> > 2.32.0
>