Re: [PATCH v6 1/5] Introduce device group

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

I feel some of my latest review opened some questions that I don't have
good answers for and might have felt a bit rambling.
So to focus the discussion:

On Sun, Jul 31, 2022 at 06:43:50PM +0300, Max Gurtovoy wrote:
> +A device can be a member of one or more device groups.

Presumably this is so we can e.g. create subfunctions inside a VF.
A VF now is a member of a SRIOV and SIOV type groups and we
can use type to distinguish between these.

We should probably be explicit that each of these groups has to
have a distinct group type then.

And this raises the question: different types have different
capabilities. So let's say admin queue is used to both
control features for SRIOV VFs and to create SIOV SFs.
I guess we'll have a feature bit to say "command to create
SIOV SFs is supported" but how do we say that this command
is only supported for VFs not SFs?

Do we just make features list a superset of what is supported and simply
say in the spec which commands are legal with which group types?


Jason Cornelia what do you think?



> +\item Self type (group identifier = 0) - this group has only one device in the group. Each virtio device is a member of at least one device group, the Self type group.

Presumably, this is here so we can send commands that refer to the
device itself as opposed to a group member (e.g. to
PF as opposed to VF). Is that right?

It's handy but again the problem here is, this refers to
device as part of which group? Let's just drop this type?


-- 
MST