[RFC QEMU PATCH] ui: Make the DisplayType enum entries conditional

[Gerd Hoffmann]

  Hi,

> > The #if CONFIG_SDL approach will not work because qemu will continue to
> > report sdl as supported even when the sdl module is not installed any
> > more.
> 
> I guess we'd need a separate QMP command to fix that, which tries to load
> the modules first when being called? Something similar to what is being done
> in qemu_display_help() ?

That would work, yes.

> That's certainly doable, too, just a little bit more complex...

Alternative idea: turn QemuDisplay into an ObjectClass, then it'll be
visible in qom introspection.  Likewise a bit more complex ...

> do we want that?  Or is the quick-n-easy way via the schema good
> enough for most use cases?

Would be better than nothing, but I'd prefer something which works
properly with modular qemu ...

> (I'm not that familiar with "virsh domcapabilities" ... is there any
> real usage for the <graphics> section or is this rather cosmetical?)

Management apps can use that info to avoid building unsupported
configurations.  Also you'll get a nice "$foo is not supported" error
from libvirt instead of libvirt dumping qemu stderr ;)

take care,
  Gerd