RE: [virtio-comment] Re: [PATCH v10 04/10] admin: introduce virtio admin virtqueues

[Parav Pandit <parav@nvidia.com>]

> From: Michael S. Tsirkin <mst@redhat.com>
> Sent: Wednesday, March 8, 2023 4:09 PM
> 
> On Wed, Mar 08, 2023 at 10:58:59PM +0200, Max Gurtovoy wrote:
> > We have a non-spec prototypes for LM so please use our experience in
> > this area.
> 
> Don't see what the fuss is about.  Nothing will prevent your device from using a
> single queue if that is what you want.

I think the use case is not clear in the cover letter on how/when multiple aq are useful or will be used.

I agree with you on this single queue should be enough provided a single queue suffices below design aspects:

The design:
a. to have one aq to support multiple outstanding commands
b. ability to execute unrelated aq commands by device in parallel
c. driver to not issue related commands to the AQ (because they are executed out of order by the device)
(Assumption is IN_ORDER is not negotiated).

Above the actual use case requirements/expectations from the AQ.

The current version indicates that the device will execute commands in-order, hence multi-queue is needed to achieve parallelism - is not serving the purpose of "q" notion fully.
Or do I miss reading v10?