Re: [Qemu-devel] [PATCH] qxl: Export "mode" as a property

[Alexander Larsson <alexl@redhat.com>]

On tis, 2012-11-20 at 11:17 +0100, Gerd Hoffmann wrote:
>   Hi,
> 
> > I'm working on a kind of "troubleshooting log" option for gnome-boxes
> > which wants to record all these kinds of data so that a helpdesk or a
> > developer can help figuring out a problem with a guest.
> 
> Understood.
> 
> > Knowing if a qxl
> > driver is in use is an important piece of information. Additionally it
> > would be very nice if the driver could report a version string that I
> > could query (same for virtio driver, etc).
> 
> Guest driver version information isn't available.

I know that, but it would be possible to add code to the driver to
register a version string.

> For QXL we could track which features are in use by the driver (i.e.
> whenever it uses sync/async io ports, ...) which might be good enougth
> for trouble shooting.

Might be useful for qxl developers, but not very useful to e.g. a
helpdesk employee trying to solve an issue for a user, as its kinda
low-level. Having the version string would be very nice here.

> For virtio it should be likewise easy to figure which device features
> the guest has activated.
> 
> If you also wanna have this for non-qxl devices (which makes sense
> indeed) going the "info spice" route doesn't make that much sense
> though.  It is probably more useful to add an (optional) "report device
> state" callback to devices which then returns this info in some useful
> format (qdict?), then wind this up as monitor command.

Sure, that would work too, as long as i can enumerate the devices and
get the data in a machine parsable format. Properties are already that,
although I realize that mixing configuration and monitoring in the same
set might be problematic.