* Peter Xu (pet...@redhat.com) wrote: > Switch the state until we try to start the VM on destination side. The > problem is that without doing this we may have a very small window that > we'll be in such a state: > > - dst VM is in postcopy-active state, > - main thread is handling MIG_CMD_PACKAGED message, which loads all the > device states, > - ram load thread is reading memory data from source. > > Then if we failed at this point when reading the migration stream we'll > also switch to postcopy-paused state, but that is not what we want. If > device states failed to load, we should fail the migration directly > instead of pause. > > Postponing the state switch to the point when we have already loaded the > devices' states and been ready to start running destination VM. > > Signed-off-by: Peter Xu <pet...@redhat.com>
If it's the only way, then this is OK; but I'd prefer you use a separate flag somewhere to let you know this, because this means that POSTCOPY_ACTIVE on the destination happens at a different point that it does on the source (and changing it on the source I think will break lots of things). Can't you use the PostcopyState value and check if it's in POSTCOPY_INCOMING_RUNNING? Dave > --- > migration/savevm.c | 10 ++++++++-- > 1 file changed, 8 insertions(+), 2 deletions(-) > > diff --git a/migration/savevm.c b/migration/savevm.c > index bc87b0e5b1..3bc792e320 100644 > --- a/migration/savevm.c > +++ b/migration/savevm.c > @@ -1584,8 +1584,6 @@ static void *postcopy_ram_listen_thread(void *opaque) > QEMUFile *f = mis->from_src_file; > int load_res; > > - migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE, > - MIGRATION_STATUS_POSTCOPY_ACTIVE); > qemu_sem_post(&mis->listen_thread_sem); > trace_postcopy_ram_listen_thread_start(); > > @@ -1748,6 +1746,14 @@ static int > loadvm_postcopy_handle_run(MigrationIncomingState *mis) > return -1; > } > > + /* > + * Declare that we are in postcopy now. We should already have > + * all the device states loaded ready when reach here, and also > + * the ram load thread running. > + */ > + migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE, > + MIGRATION_STATUS_POSTCOPY_ACTIVE); > + > data = g_new(HandleRunBhData, 1); > data->bh = qemu_bh_new(loadvm_postcopy_handle_run_bh, data); > qemu_bh_schedule(data->bh); > -- > 2.13.6 > -- Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
