Re: [virtio-comment] Re: [PATCH 0/3] Rename queue index to queue number

["Michael S. Tsirkin" <mst@redhat.com>]

On Fri, Mar 03, 2023 at 04:38:02PM +0100, Halil Pasic wrote:
> On Thu, 2 Mar 2023 16:12:48 +0000
> Parav Pandit <parav@nvidia.com> wrote:
> 
> > > >
> > > > is the index same as vq number? or something different?  
> > > 
> > > It is something different. The full paragraph sound like this
> > > 
> > > """
> > > Field \field{unclassified_queue} contains the 0-based index of the receive
> > > virtqueue to place unclassified packets in. Index 0 corresponds to receiveq1.
> > > """  
> > With vqn it can be as simply written as.
> > Field \field{unclassified_queue} contains the receive virtqueue number to use for unclassified incoming packets.
> > 
> > Similarly rss description can be simplified.
> 
> But that would change the semantics of the interface (and the ABI). And
> we really should refrain from that.
> 
> We could also say 
> 
> Field \field{unclassified_queue} contains the 0-based index of the receive
> virtqueue to place unclassified packets in. Index N corresponds to receiveqN
> and thus to virtqueue index 2N.
> Provided that we decide to change the naming of the receive queues so
> that receiveqN becomes receiveqN-1, and provided that we go with the
> virtqueue index and not with the virtqueue number wording.

This has a decent chance to confuse a lot of people.
E.g. if someone wrote "receiveq1" in their code comments,
now this suddenly refers to a different queue.

> We could also just drop the name and just say that it corresponds to the
> virtqueue index 2N like Michael has pointed out. But I would prefer the
> former.
> 
> Regards,
> Halil

I proposed virtqueue number not virtqueue index because we
said index in the past to mean N+1.
Or even better some new term.

-- 
MST