On Tue, Aug 08, 2017 at 09:02:54AM +0200, Juan Quintela wrote: > "Dr. David Alan Gilbert (git)" <dgilb...@redhat.com> wrote: > > From: "Dr. David Alan Gilbert" <dgilb...@redhat.com> > > > > There's a race if someone does a 'stop' near the end of migrate; > > the migration process goes through two runstates: > > 'finish migrate' > > 'postmigrate' > > > > If the user issues a 'stop' between the two we end up with invalid > > state transitions. > > Add the transitions as valid. > > > > Signed-off-by: Dr. David Alan Gilbert <dgilb...@redhat.com> > > Reviewed-by: Juan Quintela <quint...@redhat.com> > > To answer Peter question: > > int vm_stop(RunState state) > { > .... we don't care about this case .... > > return do_vm_stop(state); > } > > static int do_vm_stop(RunState state) > { > int ret = 0; > > if (runstate_is_running()) { > cpu_disable_ticks(); > pause_all_vcpus(); > runstate_set(state); > vm_state_notify(0, state); > qapi_event_send_stop(&error_abort); > } > > bdrv_drain_all(); > replay_disable_events(); > ret = bdrv_flush_all(); > > return ret; > } > > > int runstate_is_running(void) > { > return runstate_check(RUN_STATE_RUNNING); > } > > > So, "stop" only changes states when we are in RUNNING state. > The idea was that after migration, the only valid command (as in the > film "it should do something")is "run".
Thanks for the details. :) -- Peter Xu