[PATCH v2 0/6] Support VIRTIO_F_RING_RESET for vhost-user in virtio pci-modern

[Kangjie Xu <kangjie.xu@linux.alibaba.com>]

This patch set is based on the patch set that supports VIRTIO_F_RING_RESET for vhost-kernel:
    https://lore.kernel.org/qemu-devel/cover.1662916759.git.kangjie.xu@linux.alibaba.com/

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

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).

The detailed process is listed below:
1. VIRTIO_PCI_COMMON_Q_RESET is written [virtio-pci]
    -> virtio_queue_reset() [virtio]
        -> virtio_net_queue_reset() [virtio-net]
            -> vhost_net_virtqueue_reset() [vhost-net]
                -> vhost_virtqueue_stop()
        -> __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_virtqueue_start()
                -> vhost_user_set_vring_enable [vhost-user]
                    -> send VHOST_USER_SET_VRING_ENABLE to the device
    -> set enabled, reset status of vq.

changelog:
  1. Reuse the vhost_virtqueue_stop() when resetting a vq.

Test environment:
    Qemu: QEMU emulator version 7.1.50
    Guest: 5.19.0-rc3 (With vq reset support)
    DPDK: 22.11-rc0 (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...080d9d5a6bba8ff8dce5186e2c6cb35cabef77c9

Kangjie Xu (6):
  net: virtio: rename vhost_set_vring_enable to vhost_set_dev_enable
  vhost-user: add op to enable or disable a single vring
  vhost-net: vhost-user: update vhost_net_virtqueue_reset()
  vhost-net: vhost-user: update vhost_net_virtqueue_restart()
  virtio-net: vhost-user: update queue_reset and queue_enable
  vhost: vhost-user: enable vq reset feature

 backends/cryptodev-vhost.c        | 12 ++++++------
 hw/net/vhost_net-stub.c           |  2 +-
 hw/net/vhost_net.c                | 15 +++++++++++----
 hw/net/virtio-net.c               | 10 ++++++----
 hw/virtio/vhost-user.c            | 27 +++++++++++++++++++--------
 include/hw/virtio/vhost-backend.h |  5 ++++-
 include/net/vhost_net.h           |  2 +-
 7 files changed, 48 insertions(+), 25 deletions(-)

-- 
2.32.0