This prepares ground for the changes coming next which add an Error**
argument to the .save_setup() handler. Callers of qemu_savevm_state_setup()
now handle the error and fail earlier setting the migration state from
MIGRATION_STATUS_SETUP to MIGRATION_STATUS_FAILED.
Since the previous behavior was to ignore errors at this step of
migration, this change should be examined closely to check that
cleanups are still correctly done.
Signed-off-by: Cédric Le Goater <c...@redhat.com>
---
Changes in v3:
- Set migration state to MIGRATION_STATUS_FAILED
- Fixed error handling to be done under lock in bg_migration_thread()
- Made sure an error is always set in case of failure in
qemu_savevm_state_setup()
migration/savevm.h | 2 +-
migration/migration.c | 27 ++++++++++++++++++++++++---
migration/savevm.c | 24 ++++++++++++++----------
3 files changed, 39 insertions(+), 14 deletions(-)
diff --git a/migration/savevm.h b/migration/savevm.h
index
74669733dd63a080b765866c703234a5c4939223..9ec96a995c93a42aad621595f0ed58596c532328
100644
--- a/migration/savevm.h
+++ b/migration/savevm.h
@@ -32,7 +32,7 @@
bool qemu_savevm_state_blocked(Error **errp);
void qemu_savevm_non_migratable_list(strList **reasons);
int qemu_savevm_state_prepare(Error **errp);
-void qemu_savevm_state_setup(QEMUFile *f);
+int qemu_savevm_state_setup(QEMUFile *f, Error **errp);
bool qemu_savevm_state_guest_unplug_pending(void);
int qemu_savevm_state_resume_prepare(MigrationState *s);
void qemu_savevm_state_header(QEMUFile *f);
diff --git a/migration/migration.c b/migration/migration.c
index
bab68bcbef33edc9a78c2f4ebeccee690f4b1786..ff2d4bf9d153444d58d21f761071fe811034ea86
100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -3360,6 +3360,8 @@ static void *migration_thread(void *opaque)
int64_t setup_start = qemu_clock_get_ms(QEMU_CLOCK_HOST);
MigThrError thr_error;
bool urgent = false;
+ Error *local_err = NULL;
+ int ret;
thread = migration_threads_add("live_migration", qemu_get_thread_id());
@@ -3403,9 +3405,17 @@ static void *migration_thread(void *opaque)
}
bql_lock();
- qemu_savevm_state_setup(s->to_dst_file);
+ ret = qemu_savevm_state_setup(s->to_dst_file, &local_err);
bql_unlock();
+ if (ret) {
+ migrate_set_error(s, local_err);
+ error_free(local_err);
+ migrate_set_state(&s->state, MIGRATION_STATUS_SETUP,
+ MIGRATION_STATUS_FAILED);
+ goto out;
+ }
+
qemu_savevm_wait_unplug(s, MIGRATION_STATUS_SETUP,
MIGRATION_STATUS_ACTIVE);
@@ -3482,6 +3492,9 @@ static void *bg_migration_thread(void *opaque)
MigThrError thr_error;
QEMUFile *fb;
bool early_fail = true;
+ bool setup_fail = true;
+ Error *local_err = NULL;
+ int ret;
rcu_register_thread();
object_ref(OBJECT(s));
@@ -3515,9 +3528,16 @@ static void *bg_migration_thread(void *opaque)
bql_lock();
qemu_savevm_state_header(s->to_dst_file);
- qemu_savevm_state_setup(s->to_dst_file);
+ ret = qemu_savevm_state_setup(s->to_dst_file, &local_err);
+ if (ret) {
+ migrate_set_error(s, local_err);
+ error_free(local_err);
+ goto fail;
+ }
bql_unlock();
+ setup_fail = false;
+
qemu_savevm_wait_unplug(s, MIGRATION_STATUS_SETUP,
MIGRATION_STATUS_ACTIVE);
@@ -3584,7 +3604,8 @@ static void *bg_migration_thread(void *opaque)
fail:
if (early_fail) {
- migrate_set_state(&s->state, MIGRATION_STATUS_ACTIVE,
+ migrate_set_state(&s->state,
+ setup_fail ? MIGRATION_STATUS_SETUP : MIGRATION_STATUS_ACTIVE,
MIGRATION_STATUS_FAILED);
bql_unlock();
}
diff --git a/migration/savevm.c b/migration/savevm.c
index
e400706e61e06d2d1d03a11aed14f30a243833f2..3ae4328b95d554cb4855f96989f8685daf4b8407
100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1309,11 +1309,11 @@ int qemu_savevm_state_prepare(Error **errp)
return 0;
}
-void qemu_savevm_state_setup(QEMUFile *f)
+int qemu_savevm_state_setup(QEMUFile *f, Error **errp)
{
+ ERRP_GUARD();
MigrationState *ms = migrate_get_current();
SaveStateEntry *se;
- Error *local_err = NULL;
int ret = 0;
json_writer_int64(ms->vmdesc, "page_size", qemu_target_page_size());
@@ -1322,10 +1322,9 @@ void qemu_savevm_state_setup(QEMUFile *f)
trace_savevm_state_setup();
QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
if (se->vmsd && se->vmsd->early_setup) {
- ret = vmstate_save(f, se, ms->vmdesc, &local_err);
+ ret = vmstate_save(f, se, ms->vmdesc, errp);
if (ret) {
- migrate_set_error(ms, local_err);
- error_report_err(local_err);
+ migrate_set_error(ms, *errp);
qemu_file_set_error(f, ret);
break;
}
@@ -1345,18 +1344,19 @@ void qemu_savevm_state_setup(QEMUFile *f)
ret = se->ops->save_setup(f, se->opaque);
save_section_footer(f, se);
if (ret < 0) {
+ error_setg(errp, "failed to setup SaveStateEntry with id(name): "
+ "%d(%s): %d", se->section_id, se->idstr, ret);
qemu_file_set_error(f, ret);
break;
}
}
if (ret) {
- return;
+ return ret;
}
- if (precopy_notify(PRECOPY_NOTIFY_SETUP, &local_err)) {
- error_report_err(local_err);
- }
+ /* TODO: Should we check that errp is set in case of failure ? */
+ return precopy_notify(PRECOPY_NOTIFY_SETUP, errp);
}
int qemu_savevm_state_resume_prepare(MigrationState *s)
@@ -1727,7 +1727,10 @@ static int qemu_savevm_state(QEMUFile *f, Error **errp)
ms->to_dst_file = f;
qemu_savevm_state_header(f);
- qemu_savevm_state_setup(f);
+ ret = qemu_savevm_state_setup(f, errp);
+ if (ret) {
+ goto cleanup;
+ }
while (qemu_file_get_error(f) == 0) {
if (qemu_savevm_state_iterate(f, false) > 0) {
@@ -1743,6 +1746,7 @@ static int qemu_savevm_state(QEMUFile *f, Error **errp)
if (ret != 0) {
error_setg_errno(errp, -ret, "Error while writing VM state");
}
+cleanup:
qemu_savevm_state_cleanup();
if (ret != 0) {
--
2.44.0
