RE: [virtio] RE: [virtio-comment] proposal: use admin command (and aq) of the device to query config space

[Parav Pandit <parav@nvidia.com>]

> From: Michael S. Tsirkin <mst@redhat.com>
> Sent: Wednesday, August 2, 2023 4:56 PM
> 
> On Wed, Aug 02, 2023 at 09:57:47AM +0000, Parav Pandit wrote:
> > > If you care about admin
> > > virtqueue then device configuration space is not the only thing that
> > > can be "ever growing", common_cfg is another one.
> > The idea is to do minimal bootstrap work from the common config space and
> switch to the queue.
> > So common config shouldnât be growing either other than minimal bootstrap
> functionality.
> > Hence, common config also to be available via dma command.
> 
> That is more like a new transport. I thought this proposal is focusing on device
> specific config - let's get a handle on that first?
> "common config" is a pci transport specific thing.

Sure, device config is the real pain point we are trying to solve first.

Using cvq for those devices who has it seems the most optimal approach.
If we liberate ourselves from single monolithic config space structure and move to query device capabilities, resources, configuration, at functionality level, life is lot easier.
What are your thoughts?