OpenStack中VNC协议实现多屏共享（多屏不踢访问）

  <devices>
    <graphics type=‘sdl‘ display=‘:0.0‘/>
    <graphics type=‘vnc‘ port=‘5904‘ sharePolicy=‘allow-exclusive‘>
      <listen type=‘address‘ address=‘1.2.3.4‘/>
    </graphics>
    <graphics type=‘rdp‘ autoport=‘yes‘ multiUser=‘yes‘ />
    <graphics type=‘desktop‘ fullscreen=‘yes‘/>
    <graphics type=‘spice‘>
      <listen type=‘network‘ network=‘rednet‘/>
    </graphics>
  </devices>

class LibvirtConfigGuestGraphics(LibvirtConfigGuestDevice):
 
    def __init__(self, **kwargs):
        super(LibvirtConfigGuestGraphics, self).__init__(root_name="graphics",
                                                         **kwargs)
 
        self.type = "vnc"
        self.autoport = True
        self.keymap = None
        self.listen = None
        self.sharePolicy = "ignore"
        #test code compress
        #self.image_compression = "auto_glz"
        #self.streaming_mode = "filter"
 
    def format_dom(self):
        dev = super(LibvirtConfigGuestGraphics, self).format_dom()
 
        dev.set("type", self.type)
        if self.autoport:
            dev.set("autoport", "yes")
        else:
            dev.set("autoport", "no")
        if self.keymap:
            dev.set("keymap", self.keymap)
        if self.listen:
            dev.set("listen", self.listen)
 
        dev.set("sharePolicy", "ignore")
        #test code compress
        #self.type == "spice"
 
        #drv_image = etree.Element("image")
        #drv_image.set("compression", self.image_compression)
        #dev.append(drv_image)

        # NB some versions of libvirt support both SPICE and VNC
        # at the same time. We‘re not trying to second guess which
        # those versions are. We‘ll just let libvirt report the
        # errors appropriately if the user enables both.
        add_video_driver = False
        if ((CONF.vnc_enabled and
             CONF.libvirt.virt_type not in (‘lxc‘, ‘uml‘))):
            graphics = vconfig.LibvirtConfigGuestGraphics()
            graphics.type = "vnc"
            graphics.keymap = CONF.vnc_keymap
            graphics.listen = CONF.vncserver_listen
 
            graphics.sharePolicy = "ignore"
 
            guest.add_device(graphics)
            add_video_driver = True