Hmmm, actually, this work is handled by ```conn_finish```. And it is called in ```__call__```
As the follow : 
```        
        del self.client_hosts
        del self.server_syslibvirtd
        del self.server_libvirtdconf
        #restart libvirtd service on server
        try:
            utils_libvirtd.service_libvirtd_control(action='restart',
                                                    remote_ip=server_ip,
                                                    remote_user=server_user,
                                                    remote_pwd=server_pwd,)
        except utils_libvirtd.LibvirtdError, e:
            raise ConnServerRestartError(e)
```

The config file will be recovered in ```del xxx```, and then restart libvirtd to recover the env of remote side.

:)