1 files changed, 58 insertions, 3 deletions

diff --git a/migration/migration.c b/migration/migration.c
index f498ab84f2..2766d2f586 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -1006,6 +1006,16 @@ static void migrate_fd_cancel(MigrationState *s)
     if (s->state == MIGRATION_STATUS_CANCELLING && f) {
         qemu_file_shutdown(f);
     }
+    if (s->state == MIGRATION_STATUS_CANCELLING && s->block_inactive) {
+        Error *local_err = NULL;
+
+        bdrv_invalidate_cache_all(&local_err);
+        if (local_err) {
+            error_report_err(local_err);
+        } else {
+            s->block_inactive = false;
+        }
+    }
 }
 
 void add_migration_state_change_notifier(Notifier *notify)
@@ -1044,6 +1054,31 @@ bool migration_in_postcopy_after_devices(MigrationState *s)
     return migration_in_postcopy(s) && s->postcopy_after_devices;
 }
 
+bool migration_is_idle(MigrationState *s)
+{
+    if (!s) {
+        s = migrate_get_current();
+    }
+
+    switch (s->state) {
+    case MIGRATION_STATUS_NONE:
+    case MIGRATION_STATUS_CANCELLED:
+    case MIGRATION_STATUS_COMPLETED:
+    case MIGRATION_STATUS_FAILED:
+        return true;
+    case MIGRATION_STATUS_SETUP:
+    case MIGRATION_STATUS_CANCELLING:
+    case MIGRATION_STATUS_ACTIVE:
+    case MIGRATION_STATUS_POSTCOPY_ACTIVE:
+    case MIGRATION_STATUS_COLO:
+        return false;
+    case MIGRATION_STATUS__MAX:
+        g_assert_not_reached();
+    }
+
+    return false;
+}
+
 MigrationState *migrate_init(const MigrationParams *params)
 {
     MigrationState *s = migrate_get_current();
@@ -1086,9 +1121,24 @@ MigrationState *migrate_init(const MigrationParams *params)
 
 static GSList *migration_blockers;
 
-void migrate_add_blocker(Error *reason)
+int migrate_add_blocker(Error *reason, Error **errp)
 {
-    migration_blockers = g_slist_prepend(migration_blockers, reason);
+    if (only_migratable) {
+        error_propagate(errp, error_copy(reason));
+        error_prepend(errp, "disallowing migration blocker "
+                          "(--only_migratable) for: ");
+        return -EACCES;
+    }
+
+    if (migration_is_idle(NULL)) {
+        migration_blockers = g_slist_prepend(migration_blockers, reason);
+        return 0;
+    }
+
+    error_propagate(errp, error_copy(reason));
+    error_prepend(errp, "disallowing migration blocker (migration in "
+                      "progress) for: ");
+    return -EBUSY;
 }
 
 void migrate_del_blocker(Error *reason)
@@ -1705,6 +1755,7 @@ static void migration_completion(MigrationState *s, int current_active_state,
             if (ret >= 0) {
                 qemu_file_set_rate_limit(s->to_dst_file, INT64_MAX);
                 qemu_savevm_state_complete_precopy(s->to_dst_file, false);
+                s->block_inactive = true;
             }
         }
         qemu_mutex_unlock_iothread();
@@ -1755,10 +1806,14 @@ fail_invalidate:
     if (s->state == MIGRATION_STATUS_ACTIVE) {
         Error *local_err = NULL;
 
+        qemu_mutex_lock_iothread();
         bdrv_invalidate_cache_all(&local_err);
         if (local_err) {
             error_report_err(local_err);
+        } else {
+            s->block_inactive = false;
         }
+        qemu_mutex_unlock_iothread();
     }
 
 fail:
@@ -1969,7 +2024,7 @@ void migrate_fd_connect(MigrationState *s)
     }
 
     migrate_compress_threads_create();
-    qemu_thread_create(&s->thread, "migration", migration_thread, s,
+    qemu_thread_create(&s->thread, "live_migration", migration_thread, s,
                        QEMU_THREAD_JOINABLE);
     s->migration_thread_running = true;
 }