Thomas Huth <thuth@xxxxxxxxxx> writes: > 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. The simplest > 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. Unfortunately, this > only works for sdl, cocoa and spice, since gtk, egl-headless and curses > are hard-wired in the "data" section of the DisplayOptions, and thus > unfortunately always have to be defined. Here: { 'union' : 'DisplayOptions', 'base' : { 'type' : 'DisplayType', '*full-screen' : 'bool', '*window-close' : 'bool', '*show-cursor' : 'bool', '*gl' : 'DisplayGLMode' }, 'discriminator' : 'type', 'data' : { 'gtk' : 'DisplayGTK', 'curses' : 'DisplayCurses', 'egl-headless' : 'DisplayEGLHeadless'} } Flat union branches can be made conditional like so: 'data' : { 'gtk' : { 'type': 'DisplayGTK', 'if': 'defined(CONFIG_GTK)' }, Then you should be able to make the corresponding enum value conditional, too.
