ui: add "-display help", gtk refresh rate.

-----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2.0.22 (GNU/Linux)
 
 iQIcBAABAgAGBQJeHZFqAAoJEEy22O7T6HE4NlIQAM7GOsC8jrKVvs9q/NuyBClo
 x9WZ+Kb3OQNXXaLwjjBi9w6nRRA/E/GlFaj7yz1UYjEbrxm8VGDBtJZ91zN61jNz
 ZV017Ittcd7V594KMoVYxrsw4Nm3gt6Kux/WnL+ewR8dY6hy9zrJ3272Mq0xhd/y
 uC0c2b1TcS3eKikW6fL/0yAyxwCiPhcyw6sWxz6Igzg2J3zAsRJ0ZIsBff/7BhOa
 ZlC2E3m1s+6JYo1Zm7/hgbktExuImePoZHF6+VxX/ZJ6kONzvTiPeVZ4USGVreJm
 4JCIqhIsgmtiDQSgxeJDGzCnxMKTmuOdtVPM3V/2TaepxE5MOgUe7VQrHlNNiP2m
 6cCyvzH/mv+fncpn4Yh1xw14xkgyWzcG+XPod4oppGqbXWcyepsdHjIVW7JYhEPw
 7XM6RMzO4jjHjanVLofK752tbil+ci7MuLSttVmvCHBQ1kQObYOM3Ix+2kMwFNDP
 g8/r11ICZebrHn6EPFDvjU0+t/sCyBSsENLZFSa4FlOMPS8KzL8LpES1UB7i6xWN
 pejN8RReR7Mbr7OfFhSZLAKBkbRIvbk/6xPEXVC6aFk/fIJYB48nhEseTZ6JGEOi
 Ew0+twJOmSg1t1TZmWsJVZ8uenfqDzPNe2z2AMZ3RA2HAs+ntoCSM8wcLdmwE+o+
 vgpKU/B0geRFDdjWfm2w
 =bUTa
 -----END PGP SIGNATURE-----

Merge remote-tracking branch 'remotes/kraxel/tags/ui-20200114-pull-request' into staging

ui: add "-display help", gtk refresh rate.

# gpg: Signature made Tue 14 Jan 2020 10:01:14 GMT
# gpg:                using RSA key 4CB6D8EED3E87138
# gpg: Good signature from "Gerd Hoffmann (work) <kraxel@redhat.com>" [full]
# gpg:                 aka "Gerd Hoffmann <gerd@kraxel.org>" [full]
# gpg:                 aka "Gerd Hoffmann (private) <kraxel@gmail.com>" [full]
# Primary key fingerprint: A032 8CFF B93A 17A7 9901  FE7D 4CB6 D8EE D3E8 7138

* remotes/kraxel/tags/ui-20200114-pull-request:
  display/gtk: get proper refreshrate
  ui: Print available display backends with '-display help'

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

include/ui/console.h

@@ -442,6 +442,7 @@ void qemu_display_register(QemuDisplay *ui);
 bool qemu_display_find_default(DisplayOptions *opts);
 void qemu_display_early_init(DisplayOptions *opts);
 void qemu_display_init(DisplayState *ds, DisplayOptions *opts);
+void qemu_display_help(void);
 
 /* vnc.c */
 void vnc_display_init(const char *id, Error **errp);

include/ui/gtk.h

@@ -28,6 +28,8 @@
 #include "ui/egl-context.h"
 #endif
 
+#define MILLISEC_PER_SEC 1000000
+
 typedef struct GtkDisplayState GtkDisplayState;
 
 typedef struct VirtualGfxConsole {

qemu-options.hx

@@ -1669,7 +1669,8 @@ STEXI
 @item -display @var{type}
 @findex -display
 Select type of display to use. This option is a replacement for the
-old style -sdl/-curses/... options. Valid values for @var{type} are
+old style -sdl/-curses/... options. Use @code{-display help} to list
+the available display types. Valid values for @var{type} are
 @table @option
 @item sdl
 Display video output via SDL (usually in a separate graphics

ui/console.c

@@ -2333,6 +2333,21 @@ void qemu_display_init(DisplayState *ds, DisplayOptions *opts)
     dpys[opts->type]->init(ds, opts);
 }
 
+void qemu_display_help(void)
+{
+    int idx;
+
+    printf("Available display backend types:\n");
+    for (idx = DISPLAY_TYPE_NONE; idx < DISPLAY_TYPE__MAX; idx++) {
+        if (!dpys[idx]) {
+            ui_module_load_one(DisplayType_str(idx));
+        }
+        if (dpys[idx]) {
+            printf("%s\n",  DisplayType_str(dpys[idx]->type));
+        }
+    }
+}
+
 void qemu_chr_parse_vc(QemuOpts *opts, ChardevBackend *backend, Error **errp)
 {
     int val;

ui/gtk.c

@@ -1966,6 +1966,11 @@ static GSList *gd_vc_gfx_init(GtkDisplayState *s, VirtualConsole *vc,
                               GSList *group, GtkWidget *view_menu)
 {
     bool zoom_to_fit = false;
+    int refresh_rate_millihz;
+
+    GdkDisplay *dpy = gtk_widget_get_display(s->window);
+    GdkWindow *win = gtk_widget_get_window(s->window);
+    GdkMonitor *monitor = gdk_display_get_monitor_at_window(dpy, win);
 
     vc->label = qemu_console_get_label(con);
     vc->s = s;
@@ -2026,6 +2031,12 @@ static GSList *gd_vc_gfx_init(GtkDisplayState *s, VirtualConsole *vc,
 
     vc->gfx.kbd = qkbd_state_init(con);
     vc->gfx.dcl.con = con;
+
+    refresh_rate_millihz = gdk_monitor_get_refresh_rate(monitor);
+    if (refresh_rate_millihz) {
+        vc->gfx.dcl.update_interval = MILLISEC_PER_SEC / refresh_rate_millihz;
+    }
+
     register_displaychangelistener(&vc->gfx.dcl);
 
     gd_connect_vc_gfx_signals(vc);

vl.c

@@ -1869,6 +1869,11 @@ static void parse_display(const char *p)
 {
     const char *opts;
 
+    if (is_help_option(p)) {
+        qemu_display_help();
+        exit(0);
+    }
+
     if (strstart(p, "sdl", &opts)) {
         /*
          * sdl DisplayType needs hand-crafted parser instead of