> This set of patches is related to the reverse execution and deterministic > replay of qemu execution. It includes recording and replaying of serial > devices > and block devices operations. > > With these patches one can record and deterministically replay behavior > of the system with connected disk drives and serial communication ports > (e.g., telnet terminal). > > Patches for deterministic replay of the block devices intercept calls of > bdrv coroutine functions at the top of block drivers stack. > To record and replay block operations the drive must be configured > as following: > -drive file=disk.qcow,if=none,id=img-direct > -drive driver=blkreplay,if=none,image=img-direct,id=img-blkreplay > -device ide-hd,drive=img-blkreplay
Thanks for the great feature. A couple of questions: * Is it possible to enable/disable recording when QEMU is already running? I.e. is it ok to call replay_configure() or replay_enable() from the monitor? Would it be possible to replay such a log? * Currently, when running QEMU with the above drive configuration (even w/o icount), savevm command doesn't seem to work correctly, and subsequent loavm crashes QEMU. Is it just a bug or this feature doesn't support snapshots? * The replaying is much slower than the original scenario. Is it affected by icount shift? What shift values would allow "real time" speed? Thanks!
