On Thu, 09/29 09:47, Paolo Bonzini wrote: > > > On 29/09/2016 05:05, Fam Zheng wrote: > > > So whether we can move a certain BB from some context to another depends > > > on what the frontend supports, I don't think there is a generic answer > > > we can implement here in the generic BB code. NBD for instance allows > > > any movement; but devices probably only allow movements they have > > > initiated themselves (e.g. dataplane will allow exactly what you > > > describe here with that assertion, and any other device will probably > > > not allow anything but the main loop). > > > > Indeed, you make me think this should be an op blocker (that applies on > > whole > > graph). > > The concept of a BDS or BB's AioContext is going to disappear sooner or > later, take this into account to decide how much effort to put into > fixing this.
Taking one step back, the whole thing is so broken considering the node reference. Currently, even this is possible: -drive file=null-co://,if=virtio,id=d0 \ -drive file.file=d0,driver=raw,file.driver=raw,if=virtio AioContext is actually a factor to make it worse. Maybe we should instead think about some generic protection mechanism? Is this in the scope of new op blocker? Fam