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

[Parav Pandit <parav@nvidia.com>]

> From: Eugenio Perez Martin <eperezma@redhat.com>
> Sent: Thursday, June 8, 2023 7:54 AM

> > Yes, I have read it few times and every time I concluded that:
> > it does not say that it must be done before DRIVER_OK and cannot be done
> after DRIVER_OK.
> >
> 
> I also read it this way to be honest. From a POV, to allow it if a device does not
> handle it could be considered a fix, rather than an addition.
> 
> 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.
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.

> 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.