Re: [Qemu-devel] [RFC v2 31/33] migration: store listen task tag

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

* Peter Xu (peterx@redhat.com) wrote:
> Store the task tag for migration types: tcp/unix/fd/exec in current
> MigrationIncomingState struct.
> 
> For defered migration, no need to store task tag since there is no task
> running in the main loop at all. For RDMA, let's mark it as todo.
> 
> Signed-off-by: Peter Xu <peterx@redhat.com>

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

> ---
>  migration/migration.c | 22 ++++++++++++++++++----
>  migration/migration.h |  2 ++
>  2 files changed, 20 insertions(+), 4 deletions(-)
> 
> diff --git a/migration/migration.c b/migration/migration.c
> index c9b7085..daf356b 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -171,6 +171,7 @@ void migration_incoming_state_destroy(void)
>          mis->from_src_file = NULL;
>      }
>  
> +    mis->listen_task_tag = 0;
>      qemu_event_destroy(&mis->main_thread_load_event);
>  }
>  
> @@ -265,25 +266,31 @@ int migrate_send_rp_req_pages(MigrationIncomingState *mis, const char *rbname,
>  void qemu_start_incoming_migration(const char *uri, Error **errp)
>  {
>      const char *p;
> +    guint task_tag = 0;
> +    MigrationIncomingState *mis = migration_incoming_get_current();
>  
>      qapi_event_send_migration(MIGRATION_STATUS_SETUP, &error_abort);
>      if (!strcmp(uri, "defer")) {
>          deferred_incoming_migration(errp);
>      } else if (strstart(uri, "tcp:", &p)) {
> -        tcp_start_incoming_migration(p, errp);
> +        task_tag = tcp_start_incoming_migration(p, errp);
>  #ifdef CONFIG_RDMA
>      } else if (strstart(uri, "rdma:", &p)) {
> +        /* TODO: store task tag for RDMA migrations */
>          rdma_start_incoming_migration(p, errp);
>  #endif
>      } else if (strstart(uri, "exec:", &p)) {
> -        exec_start_incoming_migration(p, errp);
> +        task_tag = exec_start_incoming_migration(p, errp);
>      } else if (strstart(uri, "unix:", &p)) {
> -        unix_start_incoming_migration(p, errp);
> +        task_tag = unix_start_incoming_migration(p, errp);
>      } else if (strstart(uri, "fd:", &p)) {
> -        fd_start_incoming_migration(p, errp);
> +        task_tag = fd_start_incoming_migration(p, errp);
>      } else {
>          error_setg(errp, "unknown migration protocol: %s", uri);
> +        return;
>      }
> +
> +    mis->listen_task_tag = task_tag;
>  }
>  
>  static void process_incoming_migration_bh(void *opaque)
> @@ -422,6 +429,13 @@ void migration_fd_process_incoming(QEMUFile *f)
>          co = qemu_coroutine_create(process_incoming_migration_co, f);
>          qemu_coroutine_enter(co);
>      }
> +
> +    /*
> +     * When reach here, we should not need the listening port any
> +     * more. We'll detach the listening task soon, let's reset the
> +     * listen task tag.
> +     */
> +    mis->listen_task_tag = 0;
>  }
>  
>  /*
> diff --git a/migration/migration.h b/migration/migration.h
> index d041369..1f4faef 100644
> --- a/migration/migration.h
> +++ b/migration/migration.h
> @@ -26,6 +26,8 @@
>  /* State for the incoming migration */
>  struct MigrationIncomingState {
>      QEMUFile *from_src_file;
> +    /* Task tag for incoming listen port. Valid when >0. */
> +    guint listen_task_tag;
>  
>      /*
>       * Free at the start of the main state load, set as the main thread finishes
> -- 
> 2.7.4
> 
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK