xenfb: activate input handlers for raw pointer devices

If the frontend requests raw pointers, the input handlers must be
activated to have the input events delivered to the xenfb backend.
Without activation, the input events are delivered to handlers
registered earlier, which would be the emulated USB tablet or
emulated PS/2 mouse.
HVM xen_kbdfront can incorrectly scale absolute coordinates when
the display resolution is not 800x600.

Signed-off-by: Owen Smith <owen.smith@citrix.com>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>

hw/display/xenfb.c

@@ -387,6 +387,11 @@ static void input_connected(struct XenDevice *xendev)
     in->qkbd = qemu_input_handler_register((DeviceState *)in, &xenfb_keyboard);
     in->qmou = qemu_input_handler_register((DeviceState *)in,
                in->abs_pointer_wanted ? &xenfb_abs_mouse : &xenfb_rel_mouse);
+
+    if (in->raw_pointer_wanted) {
+        qemu_input_handler_activate(in->qkbd);
+        qemu_input_handler_activate(in->qmou);
+    }
 }
 
 static void input_disconnect(struct XenDevice *xendev)