migration: MigrationEvent for notifiers
Passing MigrationState to notifiers is unsound because they could access
unstable migration state internals or even modify the state. Instead, pass
the minimal info needed in a new MigrationEvent struct, which could be
extended in the future if needed.
Suggested-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/1708622920-68779-5-git-send-email-steven.sistare@oracle.com
Signed-off-by: Peter Xu <peterx@redhat.com>
diff --git a/include/migration/misc.h b/include/migration/misc.h
index b62e351..9e4abae 100644
--- a/include/migration/misc.h
+++ b/include/migration/misc.h
@@ -60,10 +60,31 @@
void migration_shutdown(void);
bool migration_is_idle(void);
bool migration_is_active(MigrationState *);
+
+typedef enum MigrationEventType {
+ MIG_EVENT_PRECOPY_SETUP,
+ MIG_EVENT_PRECOPY_DONE,
+ MIG_EVENT_PRECOPY_FAILED,
+ MIG_EVENT_MAX
+} MigrationEventType;
+
+typedef struct MigrationEvent {
+ MigrationEventType type;
+} MigrationEvent;
+
+/*
+ * Register the notifier @notify to be called when a migration event occurs
+ * for MIG_MODE_NORMAL, as specified by the MigrationEvent passed to @func.
+ * Notifiers may receive events in any of the following orders:
+ * - MIG_EVENT_PRECOPY_SETUP -> MIG_EVENT_PRECOPY_DONE
+ * - MIG_EVENT_PRECOPY_SETUP -> MIG_EVENT_PRECOPY_FAILED
+ * - MIG_EVENT_PRECOPY_FAILED
+ */
void migration_add_notifier(NotifierWithReturn *notify,
NotifierWithReturnFunc func);
+
void migration_remove_notifier(NotifierWithReturn *notify);
-void migration_call_notifiers(MigrationState *s);
+void migration_call_notifiers(MigrationState *s, MigrationEventType type);
bool migration_in_setup(MigrationState *);
bool migration_has_finished(MigrationState *);
bool migration_has_failed(MigrationState *);
