gtk: Allow to activate grab-on-hover from the command line

diff --git a/include/ui/console.h b/include/ui/console.h
index 98edf41..13420c1 100644
--- a/include/ui/console.h
+++ b/include/ui/console.h
@@ -339,6 +339,6 @@  int index_from_keycode(int code);
 
 /* gtk.c */
 void early_gtk_display_init(void);
-void gtk_display_init(DisplayState *ds, bool full_screen);
+void gtk_display_init(DisplayState *ds, bool full_screen, bool grab_on_hover);
 
 #endif
diff --git a/qemu-options.hx b/qemu-options.hx
index 5dc8b75..2cb11b5 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -809,6 +809,7 @@  ETEXI
 DEF("display", HAS_ARG, QEMU_OPTION_display,
     "-display sdl[,frame=on|off][,alt_grab=on|off][,ctrl_grab=on|off]\n"
     "            [,window_close=on|off]|curses|none|\n"
+    "            gtk[,grab_on_hover=on|off]|\n"
     "            vnc=<display>[,<optargs>]\n"
     "                select display type\n", QEMU_ARCH_ALL)
 STEXI
@@ -832,6 +833,10 @@  graphics card, but its output will not be displayed to the QEMU
 user. This option differs from the -nographic option in that it
 only affects what is done with video output; -nographic also changes
 the destination of the serial and parallel port data.
+@item gtk
+Display video output in a GTK window. This interface provides drop-down
+menus and other UI elements to configure and control the VM during
+runtime.
 @item vnc
 Start a VNC server on display <arg>
 @end table
diff --git a/ui/gtk.c b/ui/gtk.c
index b5f4f0b..43883b7 100644
--- a/ui/gtk.c
+++ b/ui/gtk.c
@@ -1443,7 +1443,7 @@  static const DisplayChangeListenerOps dcl_ops = {
     .dpy_cursor_define = gd_cursor_define,
 };
 
-void gtk_display_init(DisplayState *ds, bool full_screen)
+void gtk_display_init(DisplayState *ds, bool full_screen, bool grab_on_hover)
 {
     GtkDisplayState *s = g_malloc0(sizeof(*s));
     char *filename;
@@ -1522,6 +1522,9 @@  void gtk_display_init(DisplayState *ds, bool full_screen)
     if (full_screen) {
         gtk_menu_item_activate(GTK_MENU_ITEM(s->full_screen_item));
     }
+    if (grab_on_hover) {
+        gtk_menu_item_activate(GTK_MENU_ITEM(s->grab_on_hover_item));
+    }
 
     register_displaychangelistener(&s->dcl);
 
diff --git a/vl.c b/vl.c
index 4ad15b8..7b1b02b 100644
--- a/vl.c
+++ b/vl.c
@@ -201,6 +201,7 @@  int vga_interface_type = VGA_NONE;
 static int full_screen = 0;
 static int no_frame = 0;
 int no_quit = 0;
+static bool grab_on_hover;
 CharDriverState *serial_hds[MAX_SERIAL_PORTS];
 CharDriverState *parallel_hds[MAX_PARALLEL_PORTS];
 CharDriverState *virtcon_hds[MAX_VIRTIO_CONSOLES];
@@ -2222,6 +2223,25 @@  static DisplayType select_display(const char *p)
     } else if (strstart(p, "gtk", &opts)) {
 #ifdef CONFIG_GTK
         display = DT_GTK;
+        while (*opts) {
+            const char *nextopt;
+
+            if (strstart(opts, ",grab_on_hover=", &nextopt)) {
+                opts = nextopt;
+                if (strstart(opts, "on", &nextopt)) {
+                    grab_on_hover = true;
+                } else if (strstart(opts, "off", &nextopt)) {
+                    grab_on_hover = false;
+                } else {
+                    goto invalid_gtk_args;
+                }
+            } else {
+            invalid_gtk_args:
+                fprintf(stderr, "Invalid GTK option string: %s\n", p);
+                exit(1);
+            }
+            opts = nextopt;
+        }
 #else
         fprintf(stderr, "GTK support is disabled\n");
         exit(1);
@@ -4284,7 +4304,7 @@  int main(int argc, char **argv, char **envp)
 #endif
 #if defined(CONFIG_GTK)
     case DT_GTK:
-        gtk_display_init(ds, full_screen);
+        gtk_display_init(ds, full_screen, grab_on_hover);
         break;
 #endif
     default: