On Thu, May 30, 2019 at 07:14:14PM +0200, Hannes Reinecke wrote: >> Is this really required? I would think that a non-zero value for >> shost->nr_reserved_cmds means the same thing in practice. >> ; > My implementation actually allows for per-device reserved tags (eg for > virtio). But some drivers require to use internal commands prior to any > device setup, so they have to use a separate reserved command queue just to > be able to allocate tags. Why would virtio-scsi need per-device reserved commands? It currently uses a global mempool to allocate the reset commands.