Re: [Qemu-devel] [PATCH COLO-Frame v12 05/38] migration: Add state records for migration incoming

[Dr. David Alan Gilbert]

* zhanghailiang (address@hidden) wrote:
> For migration destination, we also need to know its state,
> we will use it in COLO.
> 
> Here we add a new member 'state' for MigrationIncomingState,
> and also use migrate_set_state() to modify its value.
> 
> Signed-off-by: zhanghailiang <address@hidden>
> Reviewed-by: Dr. David Alan Gilbert <address@hidden>

Actually note there is a bug here; see below

> ---
> v11:
> - Split exporting migrate_set_state() part into a new patch (Juan's 
> suggestion)
> 
> Signed-off-by: zhanghailiang <address@hidden>
> ---
>  include/migration/migration.h |  1 +
>  migration/migration.c         | 14 +++++++++-----
>  2 files changed, 10 insertions(+), 5 deletions(-)
> 
> diff --git a/include/migration/migration.h b/include/migration/migration.h
> index 4b19e80..99dfa92 100644
> --- a/include/migration/migration.h
> +++ b/include/migration/migration.h
> @@ -105,6 +105,7 @@ struct MigrationIncomingState {
>      QemuMutex rp_mutex;    /* We send replies from multiple threads */
>      void     *postcopy_tmp_page;
>  
> +    int state;
>      /* See savevm.c */
>      LoadStateEntry_Head loadvm_handlers;
>  };
> diff --git a/migration/migration.c b/migration/migration.c
> index c9cd80d..d58ce98 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -112,6 +112,7 @@ MigrationIncomingState 
> *migration_incoming_state_new(QEMUFile* f)
>  {
>      mis_current = g_new0(MigrationIncomingState, 1);
>      mis_current->from_src_file = f;
> +    mis_current->state = MIGRATION_STATUS_NONE;
>      QLIST_INIT(&mis_current->loadvm_handlers);
>      qemu_mutex_init(&mis_current->rp_mutex);
>      qemu_event_init(&mis_current->main_thread_load_event, false);
> @@ -332,8 +333,8 @@ static void process_incoming_migration_co(void *opaque)
>  
>      mis = migration_incoming_state_new(f);
>      postcopy_state_set(POSTCOPY_INCOMING_NONE);
> -    migrate_generate_event(MIGRATION_STATUS_ACTIVE);
> -
> +    migrate_set_state(&mis->state, MIGRATION_STATUS_NONE,
> +                      MIGRATION_STATUS_ACTIVE);
>      ret = qemu_loadvm_state(f);
>  
>      ps = postcopy_state_get();
> @@ -362,7 +363,8 @@ static void process_incoming_migration_co(void *opaque)
>      migration_incoming_state_destroy();

We're freeing mis now - we can't use the state later!

>  
>      if (ret < 0) {
> -        migrate_generate_event(MIGRATION_STATUS_FAILED);
> +        migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE,
> +                          MIGRATION_STATUS_FAILED);
>          error_report("load of migration failed: %s", strerror(-ret));
>          migrate_decompress_threads_join();
>          exit(EXIT_FAILURE);
> @@ -371,7 +373,8 @@ static void process_incoming_migration_co(void *opaque)
>      /* Make sure all file formats flush their mutable metadata */
>      bdrv_invalidate_cache_all(&local_err);
>      if (local_err) {
> -        migrate_generate_event(MIGRATION_STATUS_FAILED);
> +        migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE,
> +                          MIGRATION_STATUS_FAILED);
>          error_report_err(local_err);
>          migrate_decompress_threads_join();
>          exit(EXIT_FAILURE);
> @@ -403,7 +406,8 @@ static void process_incoming_migration_co(void *opaque)
>       * observer sees this event they might start to prod at the VM assuming
>       * it's ready to use.
>       */
> -    migrate_generate_event(MIGRATION_STATUS_COMPLETED);
> +    migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE,
> +                      MIGRATION_STATUS_COMPLETED);

So I moved the migration_incoming_state_destroy()  to here in my world.

Dave

>  }
>  
>  void process_incoming_migration(QEMUFile *f)
> -- 
> 1.8.3.1
> 
> 
--
Dr. David Alan Gilbert / address@hidden / Manchester, UK