Re: [PATCH v2 3/3] virtio: call ->vhost_reset_device() during reset

[Hanna Czenczek <hreitz@redhat.com>]

On 04.10.23 03:45, Stefan Hajnoczi wrote:
> vhost-user-scsi has a VirtioDeviceClass->reset() function that calls
> ->vhost_reset_device(). The other vhost devices don't notify the vhost
> device upon reset.
>
> Stateful vhost devices may need to handle device reset in order to free
> resources or prevent stale device state from interfering after reset.
>
> Call ->vhost_device_reset() from virtio_reset() so that that vhost
> devices are notified of device reset.
>
> This patch affects behavior as follows:
> - vhost-kernel: No change in behavior since ->vhost_reset_device() is
>    not implemented.
> - vhost-user: back-ends that negotiate
>    VHOST_USER_PROTOCOL_F_RESET_DEVICE now receive a
>    VHOST_USER_DEVICE_RESET message upon device reset. Otherwise there is
>    no change in behavior. DPDK, SPDK, libvhost-user, and the
>    vhost-user-backend crate do not negotiate
>    VHOST_USER_PROTOCOL_F_RESET_DEVICE automatically.
> - vhost-vdpa: an extra SET_STATUS 0 call is made during device reset.
>
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> ---
>   meson.build               |  1 +
>   include/hw/virtio/vhost.h | 10 ++++++++++
>   hw/scsi/vhost-user-scsi.c | 11 -----------
>   hw/virtio/vhost.c         |  9 +++++++++
>   hw/virtio/virtio.c        |  4 ++++
>   5 files changed, 24 insertions(+), 11 deletions(-)

Reviewed-by: Hanna Czenczek <hreitz@redhat.com>