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

[Alon Levy]

----- Original Message -----
> On 11/20/12 10:07, Daniel P. Berrange wrote:
> > On Tue, Nov 20, 2012 at 08:50:09AM +0100, Gerd Hoffmann wrote:
> >> On 11/19/12 14:11, Alexander Larsson wrote:
> >>> This way you can easily tell from qemu if the guest is using
> >>> a qxl driver or not.
> >>
> >> Device properties are for configuration, not inspection.
> > 
> > Sounds like we need to expose something via the monitor to let
> > admin
> > apps discover if QXL has been enabled with SPICE vs plain VGA
> > compat
> > mode only.  This is useful for apps to know, so that they can tell
> > the user that something is wrong performance wise, if the OS is
> > expected to have QXL present but does not.
> 
> Adding this to "info spice" is an option.  This has been discussed in
> the past.  IIRC we didn't actually implement it as there was not
> clear
> whenever this is actually needed or whenever management will handle
> this
> using the guest agent anyway.  Alon?

The last patchset got derailed because it was big and not clear if it was 
required. As long as info spice is already qmp'ed then I think adding mode 
there makes perfect sense. A guest agent could provide the same information, 
but since qemu already has it it saves a round trip to the guest. And 
management already needs to handle both information from the guest and from the 
vm, so this isn't complicating management either.

> 
> cheers,
>   Gerd
> 
>