Re: [PATCH 0/2] Fix expected set_vq_state behavior on vdpa_sim

From: Michael S. Tsirkin
Date: Fri Jan 27 2023 - 05:54:39 EST


On Wed, Jan 18, 2023 at 05:43:57PM +0100, Eugenio Pérez wrote:
> The use of set_vq_state is to indicate vdpa device the state of a virtqueue.
> In the case of split, it means the avail_idx. This is mandatory for use
> cases like live migration.
>
> However, vdpa_sim reset the vq state at vdpasim_queue_ready since it calls
> vringh_init_iotlb.
>
> Also, to starting from an used_idx different than 0 is needed in use cases like
> virtual machine migration. Not doing so and letting the caller set an avail
> idx different than 0 causes destination device to try to use old buffers that
> source driver already recover and are not available anymore.
>
> This series fixes both problems allowing to migrate to a vdpa_sim_net device.

Jason problems you pointed out are all consmetic do you ack
the patchset? Or expect another revision?

> Eugenio Pérez (2):
> vdpa_sim: not reset state in vdpasim_queue_ready
> vringh: fetch used_idx from vring at vringh_init_iotlb
>
> drivers/vdpa/vdpa_sim/vdpa_sim.c | 2 ++
> drivers/vhost/vringh.c | 25 +++++++++++++++++++++++--
> 2 files changed, 25 insertions(+), 2 deletions(-)
>
> --
> 2.31.1
>