@@ -102,6 +102,7 @@ static int migration_maybe_pause(MigrationState *s,
int new_state);
static void migrate_fd_cancel(MigrationState *s);
static bool close_return_path_on_source(MigrationState *s);
+static void migration_completion_end(MigrationState *s);
static void migration_downtime_start(MigrationState *s)
{
@@ -2746,8 +2747,7 @@ static void migration_completion(MigrationState *s)
migrate_set_state(&s->state, MIGRATION_STATUS_ACTIVE,
MIGRATION_STATUS_COLO);
} else {
- migrate_set_state(&s->state, current_active_state,
- MIGRATION_STATUS_COMPLETED);
+ migration_completion_end(s);
}
return;
@@ -2784,8 +2784,7 @@ static void bg_migration_completion(MigrationState *s)
goto fail;
}
- migrate_set_state(&s->state, current_active_state,
- MIGRATION_STATUS_COMPLETED);
+ migration_completion_end(s);
return;
fail:
@@ -2987,18 +2986,28 @@ static MigThrError migration_detect_error(MigrationState *s)
}
}
-static void migration_calculate_complete(MigrationState *s)
+static void migration_completion_end(MigrationState *s)
{
uint64_t bytes = migration_transferred_bytes();
int64_t end_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
int64_t transfer_time;
+ /*
+ * Take the BQL here so that query-migrate on the QMP thread sees:
+ * - atomic update of s->total_time and s->mbps;
+ * - correct ordering of s->mbps update vs. s->state;
+ */
+ bql_lock();
migration_downtime_end(s);
s->total_time = end_time - s->start_time;
transfer_time = s->total_time - s->setup_time;
if (transfer_time) {
s->mbps = ((double) bytes * 8.0) / transfer_time / 1000;
}
+
+ migrate_set_state(&s->state, s->state,
+ MIGRATION_STATUS_COMPLETED);
+ bql_unlock();
}
static void update_iteration_initial_status(MigrationState *s)
@@ -3145,7 +3154,6 @@ static void migration_iteration_finish(MigrationState *s)
bql_lock();
switch (s->state) {
case MIGRATION_STATUS_COMPLETED:
- migration_calculate_complete(s);
runstate_set(RUN_STATE_POSTMIGRATE);
break;
case MIGRATION_STATUS_COLO:
@@ -3189,9 +3197,6 @@ static void bg_migration_iteration_finish(MigrationState *s)
bql_lock();
switch (s->state) {
case MIGRATION_STATUS_COMPLETED:
- migration_calculate_complete(s);
- break;
-
case MIGRATION_STATUS_ACTIVE:
case MIGRATION_STATUS_FAILED:
case MIGRATION_STATUS_CANCELLED:
The QMP command query_migrate might see incorrect throughput numbers if it runs after we've set the migration completion status but before migration_calculate_complete() has updated s->total_time and s->mbps. The migration status would show COMPLETED, but the throughput value would be the one from the last iteration and not the one from the whole migration. This will usually be a larger value due to the time period being smaller (one iteration). Move migration_calculate_complete() earlier so that the status MIGRATION_STATUS_COMPLETED is only emitted after the final counters update. Keep everything under the BQL so the QMP thread sees the updates as atomic. Rename migration_calculate_complete to migration_completion_end to reflect its new purpose of also updating s->state. Signed-off-by: Fabiano Rosas <farosas@suse.de> --- v2: - improved comments; - took the suggestion of creating a new function but used 'end' instead of 'finalize' to avoid possible confusion with QOM. CI run: https://gitlab.com/farosas/qemu/-/pipelines/1191024660 --- migration/migration.c | 23 ++++++++++++++--------- 1 file changed, 14 insertions(+), 9 deletions(-)