[libvirt] Exposing qemu support for SDL via capabilities

[Adam Litke <agl us ibm com>]

Hi all,

In order to nicely support domains that use qemu's SDL support,
libvirt-cim is looking for a way to confirm if the underlying qemu
emulator can support SDL.  Libvirt already knows this information
internally.  It seems to me that the best way to provide this
information is by reporting it as a guest feature via the capabilities
API call.  I was thinking the node '/capabilities/guest/features/sdl'
could be added when qemu supports SDL.

Is this a good idea?

-- 
Adam Litke
IBM Linux Technology Center