> From: Jason Wang <jasowang@redhat.com>
> Sent: Tuesday, June 14, 2022 9:29 PM
> 
> Well, it's an example of how vDPA is implemented. I think we agree that for
> vDPA, vendors have the flexibility to implement their perferrable datapath.
>
Yes for the vdpa level and for the virtio level.

> >
> > I remember few months back, you acked in the weekly meeting that TC has
> approved the AQ direction.
> > And we are still in this circle of debating the AQ.
> 
> I think not. Just to make sure we are on the same page, the proposal here is
> for vDPA, and hope it can provide forward compatibility to virtio. So in the
> context of vDPA, admin virtqueue is not a must.
In context of vdpa over virtio, an efficient transport interface is needed.
If AQ is not much any other interface such as hundreds to thousands of registers is not must either.

AQ is one interface proposed with multiple benefits.
I haven’t seen any other alternatives that delivers all the benefits.
Only one I have seen is synchronous config registers.

If you let vendors progress, handful of sensible interfaces can exist, each with different characteristics.
How would we proceed from here?

On Fri, Jun 17, 2022 at 3:36 AM Parav Pandit <parav@nvidia.com> wrote:
>
>
> > From: Jason Wang <jasowang@redhat.com>
> > Sent: Tuesday, June 14, 2022 9:29 PM
> >
> > Well, it's an example of how vDPA is implemented. I think we agree that for
> > vDPA, vendors have the flexibility to implement their perferrable datapath.
> >
> Yes for the vdpa level and for the virtio level.
>
> > >
> > > I remember few months back, you acked in the weekly meeting that TC has
> > approved the AQ direction.
> > > And we are still in this circle of debating the AQ.
> >
> > I think not. Just to make sure we are on the same page, the proposal here is
> > for vDPA, and hope it can provide forward compatibility to virtio. So in the
> > context of vDPA, admin virtqueue is not a must.
> In context of vdpa over virtio, an efficient transport interface is needed.
> If AQ is not much any other interface such as hundreds to thousands of registers is not must either.
>
> AQ is one interface proposed with multiple benefits.
> I haven’t seen any other alternatives that delivers all the benefits.
> Only one I have seen is synchronous config registers.
>
> If you let vendors progress, handful of sensible interfaces can exist, each with different characteristics.
> How would we proceed from here?

I'm pretty fine with having admin virtqueue in the virtio spec. If you
remember, I've even submitted a proposal to use admin virtqueue as a
transport last year.

Let's just proceed in the virtio-dev list.

Thanks

> From: Jason Wang <jasowang@redhat.com>
> Sent: Thursday, June 16, 2022 9:15 PM
> 
> On Fri, Jun 17, 2022 at 3:36 AM Parav Pandit <parav@nvidia.com> wrote:
> >
> >
> > > From: Jason Wang <jasowang@redhat.com>
> > > Sent: Tuesday, June 14, 2022 9:29 PM
> > >
> > > Well, it's an example of how vDPA is implemented. I think we agree
> > > that for vDPA, vendors have the flexibility to implement their perferrable
> datapath.
> > >
> > Yes for the vdpa level and for the virtio level.
> >
> > > >
> > > > I remember few months back, you acked in the weekly meeting that
> > > > TC has
> > > approved the AQ direction.
> > > > And we are still in this circle of debating the AQ.
> > >
> > > I think not. Just to make sure we are on the same page, the proposal
> > > here is for vDPA, and hope it can provide forward compatibility to
> > > virtio. So in the context of vDPA, admin virtqueue is not a must.
> > In context of vdpa over virtio, an efficient transport interface is needed.
> > If AQ is not much any other interface such as hundreds to thousands of
> registers is not must either.
> >
> > AQ is one interface proposed with multiple benefits.
> > I haven’t seen any other alternatives that delivers all the benefits.
> > Only one I have seen is synchronous config registers.
> >
> > If you let vendors progress, handful of sensible interfaces can exist, each
> with different characteristics.
> > How would we proceed from here?
> 
> I'm pretty fine with having admin virtqueue in the virtio spec. If you
> remember, I've even submitted a proposal to use admin virtqueue as a
> transport last year.
> 
> Let's just proceed in the virtio-dev list.

o.k. thanks. I am aligned with your thoughts now.