Am 07.07.2015 um 15:08 schrieb Juan Quintela: > This includes a new section that for now just stores the current qemu state. > > Right now, there are only one way to control what is the state of the > target after migration. > > - If you run the target qemu with -S, it would start stopped. > - If you run the target qemu without -S, it would run just after migration > finishes. > > The problem here is what happens if we start the target without -S and > there happens one error during migration that puts current state as > -EIO. Migration would ends (notice that the error happend doing block > IO, network IO, i.e. nothing related with migration), and when > migration finish, we would just "continue" running on destination, > probably hanging the guest/corruption data, whatever. > > Signed-off-by: Juan Quintela <quint...@redhat.com> > Reviewed-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
This is bisected to cause a regression on s390. A guest restarts (booting) after managedsave/start instead of continuing. Do you have any idea what might be wrong? > --- > include/migration/migration.h | 1 + > migration/migration.c | 105 > +++++++++++++++++++++++++++++++++++++++--- > trace-events | 3 ++ > vl.c | 1 + > 4 files changed, 103 insertions(+), 7 deletions(-) > > diff --git a/include/migration/migration.h b/include/migration/migration.h > index afba233..86df6cc 100644 > --- a/include/migration/migration.h > +++ b/include/migration/migration.h > @@ -197,4 +197,5 @@ size_t ram_control_save_page(QEMUFile *f, ram_addr_t > block_offset, > > void ram_mig_init(void); > void savevm_skip_section_footers(void); > +void register_global_state(void); > #endif > diff --git a/migration/migration.c b/migration/migration.c > index c6ac08a..5e436f7 100644 > --- a/migration/migration.c > +++ b/migration/migration.c > @@ -26,6 +26,7 @@ > #include "qemu/thread.h" > #include "qmp-commands.h" > #include "trace.h" > +#include "qapi/util.h" > > #define MAX_THROTTLE (32 << 20) /* Migration speed throttling */ > > @@ -97,6 +98,83 @@ void migration_incoming_state_destroy(void) > mis_current = NULL; > } > > + > +typedef struct { > + uint32_t size; > + uint8_t runstate[100]; > +} GlobalState; > + > +static GlobalState global_state; > + > +static int global_state_store(void) > +{ > + if (!runstate_store((char *)global_state.runstate, > + sizeof(global_state.runstate))) { > + error_report("runstate name too big: %s", global_state.runstate); > + trace_migrate_state_too_big(); > + return -EINVAL; > + } > + return 0; > +} > + > +static char *global_state_get_runstate(void) > +{ > + return (char *)global_state.runstate; > +} > + > +static int global_state_post_load(void *opaque, int version_id) > +{ > + GlobalState *s = opaque; > + int ret = 0; > + char *runstate = (char *)s->runstate; > + > + trace_migrate_global_state_post_load(runstate); > + > + if (strcmp(runstate, "running") != 0) { > + Error *local_err = NULL; > + int r = qapi_enum_parse(RunState_lookup, runstate, RUN_STATE_MAX, > + -1, &local_err); > + > + if (r == -1) { > + if (local_err) { > + error_report_err(local_err); > + } > + return -EINVAL; > + } > + ret = vm_stop_force_state(r); > + } > + > + return ret; > +} > + > +static void global_state_pre_save(void *opaque) > +{ > + GlobalState *s = opaque; > + > + trace_migrate_global_state_pre_save((char *)s->runstate); > + s->size = strlen((char *)s->runstate) + 1; > +} > + > +static const VMStateDescription vmstate_globalstate = { > + .name = "globalstate", > + .version_id = 1, > + .minimum_version_id = 1, > + .post_load = global_state_post_load, > + .pre_save = global_state_pre_save, > + .fields = (VMStateField[]) { > + VMSTATE_UINT32(size, GlobalState), > + VMSTATE_BUFFER(runstate, GlobalState), > + VMSTATE_END_OF_LIST() > + }, > +}; > + > +void register_global_state(void) > +{ > + /* We would use it independently that we receive it */ > + strcpy((char *)&global_state.runstate, ""); > + vmstate_register(NULL, 0, &vmstate_globalstate, &global_state); > +} > + > /* > * Called on -incoming with a defer: uri. > * The migration can be started later after any parameters have been > @@ -164,10 +242,20 @@ static void process_incoming_migration_co(void *opaque) > exit(EXIT_FAILURE); > } > > - if (autostart) { > + /* runstate == "" means that we haven't received it through the > + * wire, so we obey autostart. runstate == runing means that we > + * need to run it, we need to make sure that we do it after > + * everything else has finished. Every other state change is done > + * at the post_load function */ > + > + if (strcmp(global_state_get_runstate(), "running") == 0) { > vm_start(); > - } else { > - runstate_set(RUN_STATE_PAUSED); > + } else if (strcmp(global_state_get_runstate(), "") == 0) { > + if (autostart) { > + vm_start(); > + } else { > + runstate_set(RUN_STATE_PAUSED); > + } > } > migrate_decompress_threads_join(); > } > @@ -793,10 +881,13 @@ static void *migration_thread(void *opaque) > qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER); > old_vm_running = runstate_is_running(); > > - ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE); > - if (ret >= 0) { > - qemu_file_set_rate_limit(s->file, INT64_MAX); > - qemu_savevm_state_complete(s->file); > + ret = global_state_store(); > + if (!ret) { > + ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE); > + if (ret >= 0) { > + qemu_file_set_rate_limit(s->file, INT64_MAX); > + qemu_savevm_state_complete(s->file); > + } > } > qemu_mutex_unlock_iothread(); > > diff --git a/trace-events b/trace-events > index a38dd2e..c0111d0 100644 > --- a/trace-events > +++ b/trace-events > @@ -1403,6 +1403,9 @@ migrate_fd_error(void) "" > migrate_fd_cancel(void) "" > migrate_pending(uint64_t size, uint64_t max) "pending size %" PRIu64 " max > %" PRIu64 > migrate_transferred(uint64_t tranferred, uint64_t time_spent, double > bandwidth, uint64_t size) "transferred %" PRIu64 " time_spent %" PRIu64 " > bandwidth %g max_size %" PRId64 > +migrate_state_too_big(void) "" > +migrate_global_state_post_load(const char *state) "loaded state: %s" > +migrate_global_state_pre_save(const char *state) "saved state: %s" > > # migration/rdma.c > qemu_rdma_accept_incoming_migration(void) "" > diff --git a/vl.c b/vl.c > index 19a8737..cfa6133 100644 > --- a/vl.c > +++ b/vl.c > @@ -4624,6 +4624,7 @@ int main(int argc, char **argv, char **envp) > return 0; > } > > + register_global_state(); > if (incoming) { > Error *local_err = NULL; > qemu_start_incoming_migration(incoming, &local_err); >