Re: [PATCH v2 1/1] vhost: Fix last queue index of devices with no cvq

[Juan Quintela]

Eugenio Pérez <eperezma@redhat.com> wrote:
Y> The -1 assumes that all devices with no cvq have an spare vq allocated
> for them, but with no offer of VIRTIO_NET_F_CTRL_VQ. This is an invalid
> device by the standard, so just stick to the right number of device
> models.
>
> This is not a problem to vhost-net, but it is to vhost-vdpa, which
> device model trust to reach the last index to finish starting the
> device.
>
> Tested with vp_vdpa with host's vhost=on and vhost=off.
>
> Fixes: 049eb15b5fc9 ("vhost: record the last virtqueue index for the
> virtio device")
> Reviewed-by: Juan Quintela <quintela@redhat.com>
> Signed-off-by: Eugenio Pérez <eperezma@redhat.com>

Much clearer, thanks.