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Diffstat (limited to 'migration/migration.c')
-rw-r--r--migration/migration.c99
1 files changed, 93 insertions, 6 deletions
diff --git a/migration/migration.c b/migration/migration.c
index 02ebd6c9d1..8392cf467d 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -2245,6 +2245,80 @@ bool migrate_colo_enabled(void)
return s->enabled_capabilities[MIGRATION_CAPABILITY_X_COLO];
}
+typedef enum MigThrError {
+ /* No error detected */
+ MIG_THR_ERR_NONE = 0,
+ /* Detected error, but resumed successfully */
+ MIG_THR_ERR_RECOVERED = 1,
+ /* Detected fatal error, need to exit */
+ MIG_THR_ERR_FATAL = 2,
+} MigThrError;
+
+/*
+ * We don't return until we are in a safe state to continue current
+ * postcopy migration. Returns MIG_THR_ERR_RECOVERED if recovered, or
+ * MIG_THR_ERR_FATAL if unrecovery failure happened.
+ */
+static MigThrError postcopy_pause(MigrationState *s)
+{
+ assert(s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE);
+ migrate_set_state(&s->state, MIGRATION_STATUS_POSTCOPY_ACTIVE,
+ MIGRATION_STATUS_POSTCOPY_PAUSED);
+
+ /* Current channel is possibly broken. Release it. */
+ assert(s->to_dst_file);
+ qemu_file_shutdown(s->to_dst_file);
+ qemu_fclose(s->to_dst_file);
+ s->to_dst_file = NULL;
+
+ error_report("Detected IO failure for postcopy. "
+ "Migration paused.");
+
+ /*
+ * We wait until things fixed up. Then someone will setup the
+ * status back for us.
+ */
+ while (s->state == MIGRATION_STATUS_POSTCOPY_PAUSED) {
+ qemu_sem_wait(&s->postcopy_pause_sem);
+ }
+
+ trace_postcopy_pause_continued();
+
+ return MIG_THR_ERR_RECOVERED;
+}
+
+static MigThrError migration_detect_error(MigrationState *s)
+{
+ int ret;
+
+ /* Try to detect any file errors */
+ ret = qemu_file_get_error(s->to_dst_file);
+
+ if (!ret) {
+ /* Everything is fine */
+ return MIG_THR_ERR_NONE;
+ }
+
+ if (s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE && ret == -EIO) {
+ /*
+ * For postcopy, we allow the network to be down for a
+ * while. After that, it can be continued by a
+ * recovery phase.
+ */
+ return postcopy_pause(s);
+ } else {
+ /*
+ * For precopy (or postcopy with error outside IO), we fail
+ * with no time.
+ */
+ migrate_set_state(&s->state, s->state, MIGRATION_STATUS_FAILED);
+ trace_migration_thread_file_err();
+
+ /* Time to stop the migration, now. */
+ return MIG_THR_ERR_FATAL;
+ }
+}
+
static void migration_calculate_complete(MigrationState *s)
{
uint64_t bytes = qemu_ftell(s->to_dst_file);
@@ -2401,6 +2475,7 @@ static void *migration_thread(void *opaque)
{
MigrationState *s = opaque;
int64_t setup_start = qemu_clock_get_ms(QEMU_CLOCK_HOST);
+ MigThrError thr_error;
rcu_register_thread();
@@ -2450,13 +2525,22 @@ static void *migration_thread(void *opaque)
}
}
- if (qemu_file_get_error(s->to_dst_file)) {
- if (migration_is_setup_or_active(s->state)) {
- migrate_set_state(&s->state, s->state,
- MIGRATION_STATUS_FAILED);
- }
- trace_migration_thread_file_err();
+ /*
+ * Try to detect any kind of failures, and see whether we
+ * should stop the migration now.
+ */
+ thr_error = migration_detect_error(s);
+ if (thr_error == MIG_THR_ERR_FATAL) {
+ /* Stop migration */
break;
+ } else if (thr_error == MIG_THR_ERR_RECOVERED) {
+ /*
+ * Just recovered from a e.g. network failure, reset all
+ * the local variables. This is important to avoid
+ * breaking transferred_bytes and bandwidth calculation
+ */
+ s->iteration_start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
+ s->iteration_initial_bytes = 0;
}
current_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
@@ -2614,6 +2698,7 @@ static void migration_instance_finalize(Object *obj)
g_free(params->tls_hostname);
g_free(params->tls_creds);
qemu_sem_destroy(&ms->pause_sem);
+ qemu_sem_destroy(&ms->postcopy_pause_sem);
error_free(ms->error);
}
@@ -2643,6 +2728,8 @@ static void migration_instance_init(Object *obj)
params->has_x_multifd_channels = true;
params->has_x_multifd_page_count = true;
params->has_xbzrle_cache_size = true;
+
+ qemu_sem_init(&ms->postcopy_pause_sem, 0);
}
/*