Re: [PATCH v2] ui: Make the DisplayType enum entries conditional

Libvirt's "domcapabilities" command has a way to state whether certain graphic frontends are available in QEMU or not. Originally, libvirt looked at the "--help" output of the QEMU binary to determine whether SDL was available or not (by looking for the "-sdl" parameter in the help text), but since libvirt stopped doing this analysis of the help text, the detection of SDL is currently broken, see: https://bugzilla.redhat.com/show_bug.cgi?id=1790902 QEMU should provide a way via the QMP interface instead. A simple way, without introducing additional commands, is to make the DisplayType enum entries conditional, so that the enum only contains the entries if the corresponding CONFIG_xxx switches have been set. This of course only gives an indication which possibilities have been enabled during compile-time of QEMU (and does not take into account whether modules are later available or not for example - for this we'd need a separate command), but anyway, this should already be good enough for the above bug ticket, and it's a good idea anyway to make the QMP interface conditional here, so let's simply do it. Signed-off-by: Thomas Huth <thuth(a)redhat.com&gt;