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

[Stefan Hajnoczi]

On Tue, 3 Oct 2023 at 17:01, Michael S. Tsirkin <mst@redhat.com> wrote:
>
> 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

Sorry about that, will fix.

Stefan

> >  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
>
>