display: add -display spice-app launching a Spice client

Add a new display backend that will configure Spice to allow a remote
client to control QEMU in a similar fashion as other QEMU display
backend/UI like GTK.

For this to work, it will set up Spice server with a unix socket, and
register a VC chardev that will be exposed as Spice ports. A QMP
monitor is also exposed as a Spice port, this allows the remote client
fuller qemu control and state handling.

- doesn't handle VC set_echo() - this doesn't seem a strong
  requirement, very few front-end use it
- spice options can be tweaked with other -spice arguments
- Windows support shouldn't be hard to do, but will probably use a TCP
  port instead
- we may want to watch the child process to quit automatically if it
  crashed

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Tested-by: Victor Toso <victortoso@redhat.com>
Message-id: 20190221110703.5775-12-marcandre.lureau@redhat.com

[ kraxel: squash incremental fix ]

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/qemu-options.hx b/qemu-options.hx
index 77bd98e20b..c843126ebd 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -1211,6 +1211,7 @@ STEXI
 ETEXI
 
 DEF("display", HAS_ARG, QEMU_OPTION_display,
+    "-display spice-app[,gl=on|off]\n"
     "-display sdl[,frame=on|off][,alt_grab=on|off][,ctrl_grab=on|off]\n"
     "            [,window_close=on|off][,gl=on|core|es|off]\n"
     "-display gtk[,grab_on_hover=on|off][,gl=on|off]|\n"
@@ -1262,6 +1263,10 @@ Start a VNC server on display <arg>
 @item egl-headless
 Offload all OpenGL operations to a local DRI device. For any graphical display,
 this display needs to be paired with either VNC or SPICE displays.
+@item spice-app
+Start QEMU as a Spice server and launch the default Spice client
+application. The Spice server will redirect the serial consoles and
+QEMU monitors. (Since 4.0)
 @end table
 ETEXI