Re: [virtio-dev][RFC PATCH v1 2/2] virtio-gpu: add the ability to export resources

[David Stevens <stevensd@chromium.org>]

> ok but how is this then used? will there be more commands to pass
> this uuid to another device?

This is intended to be used with the virtio video device being
discussed here https://markmail.org/thread/ingyqlps4rbcuazh. I don't
have a specific patch for how that will work, but it will likely be an
extension to VIRTIO_VIDEO_T_RESOURCE_CREATE.

> > +The response contains a uuid which identifies the exported object created from
> > +the host private resource.
>
> Are the uuids as specified in rfc-4122? I guess we need to link to that spec then

I don't think it's terribly important to specify how the uuids are
generated, as long as they're actually unique. That being said, I'm
not opposed to defining them as rfc-4122 version 4 uuids. Although if
we do that, it should go in the patch that defines what exported
objects and uuids are in the context of virtio, not in the virtio-gpu
section.

> > Note that if the resource has an attached backing,
> > +modifications made to the host private resource through the exported object by
> > +other devices are not visible in the attached backing until they are
> > transferred
> > +into the backing.
> > +
>
> s/host/device/?

The virtio-gpu is based around "resources private to the host", to
quote the existing specification. I think consistency with that
language is important.

-David