RE: [virtio-comment] RE: [PATCH 1/2] virtio: introduce selective queue enabling

[Parav Pandit <parav@nvidia.com>]

> From: Michael S. Tsirkin <mst@redhat.com>
> Sent: Thursday, June 8, 2023 11:06 AM

> > > I'm assuming we need to modify the standard just because it was not
> > > explicitly allowed. To explicitly allow it before DRIVER_OK was not
> > > needed because it was already widespread.
> > >
> > It was explicit enough that queues can be enabled after DRIVER_OK.
> 
> Weird, there's spec text saying they can't.
> 
So far no one cited that text here. :)
You pointed to the general initialization section but it doesnt specify.

> > And queue reset is the perfect example showed that.
> > Who ever implements the device should be ready to handle queue_enable
> writes after DRIVER_OK stage, it is really that simple.
> > There is no need of new feature bit.
> 
> Hard to change the past, we didn't ask people to do it.
> 
> > > It would be great for me if we agree the device must support it, but
> > > maybe it is just too late for that.
> > Device must support it. There is nothing late about it.
> > And if you are considering LM flow, then for sure it is not late because LM is
> just not fully baked.
> 
> Considering regular use, no LM.

_RESET is the existing feature bit that allows one to enable queues after DRIVER_OK.