Introduce -display argument

This patch introduces a -display argument which consolidates the
setting of the display mode. Valid options are:
sdl/curses/default
Signed-off-by: NJes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

qemu-options.hx

@@ -590,6 +590,28 @@ STEXI
 @table @option
 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\n"
+    "                select display type\n", QEMU_ARCH_ALL)
+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
+@table @option
+@item sdl
+Display video output via SDL (usually in a separate graphics
+window; see the SDL documentation for other possibilities).
+@item curses
+Display video output via curses. For graphics device models which
+support a text mode, QEMU can display this output using a
+curses/ncurses interface. Nothing is displayed when the graphics
+device is in graphical mode or if the graphics device does not support
+a text mode. Generally only the VGA device models support text mode.
+@end table
+ETEXI
+
 DEF("nographic", 0, QEMU_OPTION_nographic,
     "-nographic      disable graphical output and redirect serial I/Os to console\n",
     QEMU_ARCH_ALL)

vl.c

@@ -1555,6 +1555,78 @@ static void select_vgahw (const char *p)
     }
 }
 
+static DisplayType select_display(const char *p)
+{
+    const char *opts;
+    DisplayType display = DT_DEFAULT;
+
+    if (strstart(p, "sdl", &opts)) {
+#ifdef CONFIG_SDL
+        display = DT_SDL;
+        while (*opts) {
+            const char *nextopt;
+
+            if (strstart(opts, ",frame=", &nextopt)) {
+                opts = nextopt;
+                if (strstart(opts, "on", &nextopt)) {
+                    no_frame = 0;
+                } else if (strstart(opts, "off", &nextopt)) {
+                    no_frame = 1;
+                } else {
+                    goto invalid_display;
+                }
+            } else if (strstart(opts, ",alt_grab=", &nextopt)) {
+                opts = nextopt;
+                if (strstart(opts, "on", &nextopt)) {
+                    alt_grab = 1;
+                } else if (strstart(opts, "off", &nextopt)) {
+                    alt_grab = 0;
+                } else {
+                    goto invalid_display;
+                }
+            } else if (strstart(opts, ",ctrl_grab=", &nextopt)) {
+                opts = nextopt;
+                if (strstart(opts, "on", &nextopt)) {
+                    ctrl_grab = 1;
+                } else if (strstart(opts, "off", &nextopt)) {
+                    ctrl_grab = 0;
+                } else {
+                    goto invalid_display;
+                }
+            } else if (strstart(opts, ",window_close=", &nextopt)) {
+                opts = nextopt;
+                if (strstart(opts, "on", &nextopt)) {
+                    no_quit = 0;
+                } else if (strstart(opts, "off", &nextopt)) {
+                    no_quit = 1;
+                } else {
+                    goto invalid_display;
+                }
+            } else {
+                goto invalid_display;
+            }
+            opts = nextopt;
+        }
+#else
+        fprintf(stderr, "SDL support is disabled\n");
+        exit(1);
+#endif
+    } else if (strstart(p, "curses", &opts)) {
+#ifdef CONFIG_CURSES
+        display = DT_CURSES;
+#else
+        fprintf(stderr, "Curses support is disabled\n");
+        exit(1);
+#endif
+    } else {
+    invalid_display:
+        fprintf(stderr, "Unknown display type: %s\n", p);
+        exit(1);
+    }
+
+    return display;
+}
+
 static int balloon_parse(const char *arg)
 {
     QemuOpts *opts;
@@ -2153,6 +2225,9 @@ int main(int argc, char **argv, char **envp)
                 }
                 numa_add(optarg);
                 break;
+            case QEMU_OPTION_display:
+                display_type = select_display(optarg);
+                break;
             case QEMU_OPTION_nographic:
                 display_type = DT_NOGRAPHIC;
                 break;