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@redhat.com>
Message-Id: <20210615090439.70926-1-thuth@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
This commit is contained in:
Thomas Huth 2021-06-15 11:04:39 +02:00 committed by Gerd Hoffmann
parent ddc717581c
commit 66c2207fd2
3 changed files with 41 additions and 10 deletions

View File

@ -1130,9 +1130,16 @@
#
##
{ 'enum' : 'DisplayType',
'data' : [ 'default', 'none', 'gtk', 'sdl',
'egl-headless', 'curses', 'cocoa',
'spice-app'] }
'data' : [
{ 'name': 'default' },
{ 'name': 'none' },
{ 'name': 'gtk', 'if': 'defined(CONFIG_GTK)' },
{ 'name': 'sdl', 'if': 'defined(CONFIG_SDL)' },
{ 'name': 'egl-headless',
'if': 'defined(CONFIG_OPENGL) && defined(CONFIG_GBM)' },
{ 'name': 'curses', 'if': 'defined(CONFIG_CURSES)' },
{ 'name': 'cocoa', 'if': 'defined(CONFIG_COCOA)' },
{ 'name': 'spice-app', 'if': 'defined(CONFIG_SPICE)'} ] }
##
# @DisplayOptions:
@ -1156,9 +1163,13 @@
'*show-cursor' : 'bool',
'*gl' : 'DisplayGLMode' },
'discriminator' : 'type',
'data' : { 'gtk' : 'DisplayGTK',
'curses' : 'DisplayCurses',
'egl-headless' : 'DisplayEGLHeadless'} }
'data' : {
'gtk': { 'type': 'DisplayGTK', 'if': 'defined(CONFIG_GTK)' },
'curses': { 'type': 'DisplayCurses', 'if': 'defined(CONFIG_CURSES)' },
'egl-headless': { 'type': 'DisplayEGLHeadless',
'if': 'defined(CONFIG_OPENGL) && defined(CONFIG_GBM)' }
}
}
##
# @query-display-options:

View File

@ -1068,6 +1068,7 @@ static void parse_display(const char *p)
* Not clear yet what happens to them long-term. Should
* replaced by something better or deprecated and dropped.
*/
#if defined(CONFIG_SDL)
dpy.type = DISPLAY_TYPE_SDL;
while (*opts) {
const char *nextopt;
@ -1131,6 +1132,10 @@ static void parse_display(const char *p)
}
opts = nextopt;
}
#else
error_report("SDL display supported is not available in this binary");
exit(1);
#endif
} else if (strstart(p, "vnc", &opts)) {
/*
* vnc isn't a (local) DisplayType but a protocol for remote
@ -1867,13 +1872,22 @@ static void qemu_apply_machine_options(void)
static void qemu_create_early_backends(void)
{
MachineClass *machine_class = MACHINE_GET_CLASS(current_machine);
#if defined(CONFIG_SDL)
const bool use_sdl = (dpy.type == DISPLAY_TYPE_SDL);
#else
const bool use_sdl = false;
#endif
#if defined(CONFIG_GTK)
const bool use_gtk = (dpy.type == DISPLAY_TYPE_GTK);
#else
const bool use_gtk = false;
#endif
if ((alt_grab || ctrl_grab) && dpy.type != DISPLAY_TYPE_SDL) {
if ((alt_grab || ctrl_grab) && !use_sdl) {
error_report("-alt-grab and -ctrl-grab are only valid "
"for SDL, ignoring option");
}
if (dpy.has_window_close &&
(dpy.type != DISPLAY_TYPE_GTK && dpy.type != DISPLAY_TYPE_SDL)) {
if (dpy.has_window_close && !use_gtk && !use_sdl) {
error_report("-no-quit is only valid for GTK and SDL, "
"ignoring option");
}

View File

@ -2370,13 +2370,19 @@ void qemu_display_register(QemuDisplay *ui)
bool qemu_display_find_default(DisplayOptions *opts)
{
static DisplayType prio[] = {
#if defined(CONFIG_GTK)
DISPLAY_TYPE_GTK,
#endif
#if defined(CONFIG_SDL)
DISPLAY_TYPE_SDL,
#endif
#if defined(CONFIG_COCOA)
DISPLAY_TYPE_COCOA
#endif
};
int i;
for (i = 0; i < ARRAY_SIZE(prio); i++) {
for (i = 0; i < (int)ARRAY_SIZE(prio); i++) {
if (dpys[prio[i]] == NULL) {
ui_module_load_one(DisplayType_str(prio[i]));
}