Re: [PATCH 0/3] vhost: clean up device reset

["Michael S. Tsirkin" <mst@redhat.com>]

On Wed, Sep 27, 2023 at 03:27:34PM -0400, Stefan Hajnoczi wrote:
> Stateful vhost devices may need to free resources or clear device state upon
> device reset. The vhost-user protocol has a VHOST_USER_RESET_DEVICE message for
> this and vDPA has SET_STATUS 0, but only QEMU's vhost-user-scsi device actually
> implements this today.
> 
> This patch series performs device reset across all device types. When
> virtio_reset() is called, the associated vhost_dev's ->vhost_reset_device() is
> called. vhost-user-scsi's one-off implementation is obsoleted and removed.
> 
> This patch affects behavior as follows:
> - vhost-kernel: no change in behavior. No ioctl calls are made.
> - 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.
> 
> I have tested this series with vhost-net (kernel), vhost-user-blk, and
> vhost-user-fs (both Rust and legacy C).
> 
> Stefan Hajnoczi (3):
>   vhost-user: do not send RESET_OWNER on device reset
>   vhost-backend: remove vhost_kernel_reset_device()
>   virtio: call ->vhost_reset_device() during reset

Build failure:
https://gitlab.com/mstredhat/qemu/-/jobs/5215049540


>  include/hw/virtio/vhost.h |  3 +++
>  hw/scsi/vhost-user-scsi.c | 20 --------------------
>  hw/virtio/vhost-backend.c |  6 ------
>  hw/virtio/vhost-user.c    | 13 +++++++++----
>  hw/virtio/vhost.c         |  9 +++++++++
>  hw/virtio/virtio.c        |  4 ++++
>  6 files changed, 25 insertions(+), 30 deletions(-)
> 
> -- 
> 2.41.0