From 9535435795983caa31070b8b642539b5a658dc2f Mon Sep 17 00:00:00 2001 From: Arun Menon Date: Thu, 18 Sep 2025 20:53:24 +0530 Subject: [PATCH] migration: push Error **errp into qemu_loadvm_state() MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit This is an incremental step in converting vmstate loading code to report error via Error objects instead of directly printing it to console/monitor. It is ensured that qemu_loadvm_state() must report an error in errp, in case of failure. When postcopy live migration runs, the device states are loaded by both the qemu coroutine process_incoming_migration_co() and the postcopy_ram_listen_thread(). Therefore, it is important that the coroutine also reports the error in case of failure, with error_report_err(). Otherwise, the source qemu will not display any errors before going into the postcopy pause state. Suggested-by: Akihiko Odaki Reviewed-by: Marc-André Lureau Reviewed-by: Fabiano Rosas Signed-off-by: Arun Menon Tested-by: Fabiano Rosas Reviewed-by: Akihiko Odaki Link: https://lore.kernel.org/r/20250918-propagate_tpm_error-v14-7-36f11a6fb9d3@redhat.com Signed-off-by: Peter Xu --- migration/migration.c | 14 ++++++++++++-- migration/savevm.c | 30 ++++++++++++++++++------------ migration/savevm.h | 2 +- 3 files changed, 31 insertions(+), 15 deletions(-) diff --git a/migration/migration.c b/migration/migration.c index e1ac4d73c2b..cba2a393555 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -881,7 +881,7 @@ process_incoming_migration_co(void *opaque) MIGRATION_STATUS_ACTIVE); mis->loadvm_co = qemu_coroutine_self(); - ret = qemu_loadvm_state(mis->from_src_file); + ret = qemu_loadvm_state(mis->from_src_file, &local_err); mis->loadvm_co = NULL; trace_vmstate_downtime_checkpoint("dst-precopy-loadvm-completed"); @@ -908,7 +908,8 @@ process_incoming_migration_co(void *opaque) } if (ret < 0) { - error_setg(&local_err, "load of migration failed: %s", strerror(-ret)); + error_prepend(&local_err, "load of migration failed: %s: ", + strerror(-ret)); goto fail; } @@ -935,6 +936,15 @@ fail: } exit(EXIT_FAILURE); + } else { + /* + * Report the error here in case that QEMU abruptly exits + * when postcopy is enabled. + */ + WITH_QEMU_LOCK_GUARD(&s->error_mutex) { + error_report_err(s->error); + s->error = NULL; + } } out: /* Pairs with the refcount taken in qmp_migrate_incoming() */ diff --git a/migration/savevm.c b/migration/savevm.c index 5e54651652e..88116ed278a 100644 --- a/migration/savevm.c +++ b/migration/savevm.c @@ -3159,28 +3159,24 @@ out: return ret; } -int qemu_loadvm_state(QEMUFile *f) +int qemu_loadvm_state(QEMUFile *f, Error **errp) { MigrationState *s = migrate_get_current(); MigrationIncomingState *mis = migration_incoming_get_current(); - Error *local_err = NULL; int ret; - if (qemu_savevm_state_blocked(&local_err)) { - error_report_err(local_err); + if (qemu_savevm_state_blocked(errp)) { return -EINVAL; } qemu_loadvm_thread_pool_create(mis); - ret = qemu_loadvm_state_header(f, &local_err); + ret = qemu_loadvm_state_header(f, errp); if (ret) { - error_report_err(local_err); return ret; } - if (qemu_loadvm_state_setup(f, &local_err) != 0) { - error_report_err(local_err); + if (qemu_loadvm_state_setup(f, errp) != 0) { return -EINVAL; } @@ -3191,6 +3187,9 @@ int qemu_loadvm_state(QEMUFile *f) cpu_synchronize_all_pre_loadvm(); ret = qemu_loadvm_state_main(f, mis); + if (ret < 0) { + error_setg(errp, "Load VM state failed: %d", ret); + } qemu_event_set(&mis->main_thread_load_event); trace_qemu_loadvm_state_post_main(ret); @@ -3208,8 +3207,15 @@ int qemu_loadvm_state(QEMUFile *f) if (migrate_has_error(migrate_get_current()) || !qemu_loadvm_thread_pool_wait(s, mis)) { ret = -EINVAL; + error_setg(errp, + "Error while loading vmstate"); } else { ret = qemu_file_get_error(f); + if (ret < 0) { + error_setg(errp, + "Error while loading vmstate: stream error: %d", + ret); + } } } /* @@ -3474,6 +3480,7 @@ void qmp_xen_save_devices_state(const char *filename, bool has_live, bool live, void qmp_xen_load_devices_state(const char *filename, Error **errp) { + ERRP_GUARD(); QEMUFile *f; QIOChannelFile *ioc; int ret; @@ -3495,10 +3502,10 @@ void qmp_xen_load_devices_state(const char *filename, Error **errp) f = qemu_file_new_input(QIO_CHANNEL(ioc)); object_unref(OBJECT(ioc)); - ret = qemu_loadvm_state(f); + ret = qemu_loadvm_state(f, errp); qemu_fclose(f); if (ret < 0) { - error_setg(errp, "loading Xen device state failed"); + error_prepend(errp, "loading Xen device state failed: "); } migration_incoming_state_destroy(); } @@ -3569,13 +3576,12 @@ bool load_snapshot(const char *name, const char *vmstate, ret = -EINVAL; goto err_drain; } - ret = qemu_loadvm_state(f); + ret = qemu_loadvm_state(f, errp); migration_incoming_state_destroy(); bdrv_drain_all_end(); if (ret < 0) { - error_setg(errp, "Error %d while loading VM state", ret); return false; } diff --git a/migration/savevm.h b/migration/savevm.h index 2d5e9c71668..b80770b7461 100644 --- a/migration/savevm.h +++ b/migration/savevm.h @@ -64,7 +64,7 @@ void qemu_savevm_send_colo_enable(QEMUFile *f); void qemu_savevm_live_state(QEMUFile *f); int qemu_save_device_state(QEMUFile *f); -int qemu_loadvm_state(QEMUFile *f); +int qemu_loadvm_state(QEMUFile *f, Error **errp); void qemu_loadvm_state_cleanup(MigrationIncomingState *mis); int qemu_loadvm_state_main(QEMUFile *f, MigrationIncomingState *mis); int qemu_load_device_state(QEMUFile *f); -- 2.47.3