At Mon, 23 Apr 2012 02:20:49 -0400, Christoph Hellwig wrote: > > On Fri, Apr 20, 2012 at 12:55:33PM -0700, MORITA Kazutaka wrote: > > At Fri, 20 Apr 2012 15:15:38 -0400, > > Christoph Hellwig wrote: > > > > > > On Fri, Apr 20, 2012 at 09:25:52AM +0000, Huxinwei wrote: > > > > What if the old code from qemu connects to the latest sheepdog with basic data structure changed ? > > > > Will it destroy our precious data ? > > > > > > > > Btw: It seems that we don't have version defined for client-server communication. Is that right ? > > > > > > Seems like it doesn't exist, but really should. But even with > > > > SD_PROTO_VER is the protocol version number between client and server. > > It is checked when the VDI is opened. > > I know that part, but it doesn't really help to negotiate optional > protocol features between client and gateway. For that the client would > have to send a bitmap of supported features to the gateway, and the > gateway would respond with which bits it supports. Similar to how e.g. > the virtio feature negotiation works. Agreed. Looks better than incrementing SD_PROTO_VER blindly since the negotiation allows us to support different version of QEMUs easily. Thanks, Kazutaka |