On Mon, Jul 24, 2023 at 05:21:37PM +0000, Raphael Norwitz wrote: > Very excited to see this. High level looks good modulo a few small things. > > My major concern is around existing vhost-user-scsi backends which don’t > support VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD. IMO we should hide the > reconnect behavior behind a VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD check. We > may want to do the same for vhost-user-blk. > > The question is then what happens if the check is false. IIUC without an > inflight FD, if a device processes requests out of order, it’s not safe to > continue execution on reconnect, as there’s no way for the backend to know > how to replay IO. Should we permanently wedge the device or have QEMU fail > out? May be nice to have a toggle for this.
No, device itself can store the state somewhere. And if it wants to, it can check VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD and fail reconnect. -- MST
