From: Avihai Horon <[email protected]> migration_completion_precopy() doesn't propagate errors to migration core which leads to error information loss. Fix that.
This prepares for a follow-up where migration_switchover_start() can fail on switchover-ack and still report a useful error. Reviewed-by: Philippe Mathieu-Daudé <[email protected]> Reviewed-by: Peter Xu <[email protected]> Signed-off-by: Avihai Horon <[email protected]> Reviewed-by: Cédric Le Goater <[email protected]> Link: https://lore.kernel.org/qemu-devel/[email protected] [ clg: error_prepend adjustment in qemu_savevm_state_complete_precopy() ] Signed-off-by: Cédric Le Goater <[email protected]> --- migration/savevm.h | 2 +- migration/migration.c | 13 ++++++++----- migration/savevm.c | 29 +++++++++++++++++------------ 3 files changed, 26 insertions(+), 18 deletions(-) diff --git a/migration/savevm.h b/migration/savevm.h index 96fdf96d4ef6f7fd174f50e8c1402f0b6d6b9e1f..b6bb4fa977fae84ed121b0668cdefdf49e3d9c67 100644 --- a/migration/savevm.h +++ b/migration/savevm.h @@ -44,7 +44,7 @@ void qemu_savevm_state_header(QEMUFile *f); int qemu_savevm_state_iterate(QEMUFile *f, bool postcopy); void qemu_savevm_state_cleanup(void); void qemu_savevm_state_complete_postcopy(QEMUFile *f); -int qemu_savevm_state_complete_precopy(MigrationState *s); +int qemu_savevm_state_complete_precopy(MigrationState *s, Error **errp); void qemu_savevm_query_pending(MigPendingData *pending, bool exact); int qemu_savevm_state_complete_precopy_iterable(QEMUFile *f, bool in_postcopy); bool qemu_savevm_state_postcopy_prepare(QEMUFile *f, Error **errp); diff --git a/migration/migration.c b/migration/migration.c index 278cad502aebca133dd5fd41363980f9bf9ad496..0f9e891cf85c8e5074f7f9800515e244fa413fa2 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -2814,7 +2814,7 @@ static bool migration_switchover_start(MigrationState *s, Error **errp) return true; } -static int migration_completion_precopy(MigrationState *s) +static int migration_completion_precopy(MigrationState *s, Error **errp) { int ret; @@ -2823,16 +2823,17 @@ static int migration_completion_precopy(MigrationState *s) if (!migrate_mode_is_cpr()) { ret = migration_stop_vm(s, RUN_STATE_FINISH_MIGRATE); if (ret < 0) { + error_setg_errno(errp, -ret, "Failed to stop the VM"); goto out_unlock; } } - if (!migration_switchover_start(s, NULL)) { + if (!migration_switchover_start(s, errp)) { ret = -EFAULT; goto out_unlock; } - ret = qemu_savevm_state_complete_precopy(s); + ret = qemu_savevm_state_complete_precopy(s, errp); out_unlock: bql_unlock(); return ret; @@ -2869,7 +2870,7 @@ static void migration_completion(MigrationState *s) Error *local_err = NULL; if (s->state == MIGRATION_STATUS_ACTIVE) { - ret = migration_completion_precopy(s); + ret = migration_completion_precopy(s, &local_err); } else if (s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE) { migration_completion_postcopy(s); } else { @@ -2900,7 +2901,9 @@ static void migration_completion(MigrationState *s) return; fail: - if (qemu_file_get_error_obj(s->to_dst_file, &local_err)) { + if (local_err) { + migrate_error_propagate(s, local_err); + } else if (qemu_file_get_error_obj(s->to_dst_file, &local_err)) { migrate_error_propagate(s, local_err); } else if (ret) { error_setg_errno(&local_err, -ret, "Error in migration completion"); diff --git a/migration/savevm.c b/migration/savevm.c index 23adaf9dd9263b8dafe808f0637724fe4a5482b2..7e2a0c2b4a7470d9c2159eac1d18ae891740fe3e 100644 --- a/migration/savevm.c +++ b/migration/savevm.c @@ -1771,28 +1771,34 @@ int qemu_savevm_state_non_iterable(QEMUFile *f, Error **errp) return 0; } -int qemu_savevm_state_complete_precopy(MigrationState *s) +int qemu_savevm_state_complete_precopy(MigrationState *s, Error **errp) { + ERRP_GUARD(); QEMUFile *f = s->to_dst_file; - Error *local_err = NULL; int ret; ret = qemu_savevm_state_complete_precopy_iterable(f, false); if (ret) { + qemu_file_get_error_obj(f, errp); + error_prepend(errp, "Failed to save iterable device state: "); return ret; } - /* TODO: pass error upper */ - ret = qemu_savevm_state_non_iterable(f, &local_err); + ret = qemu_savevm_state_non_iterable(f, errp); if (ret) { - migrate_error_propagate(s, error_copy(local_err)); - error_report_err(local_err); return ret; } qemu_savevm_state_end_precopy(s, f); - return qemu_fflush(f); + ret = qemu_fflush(f); + if (ret) { + qemu_file_get_error_obj(f, errp); + error_prepend(errp, "Failed to flush QEMUFile: "); + return ret; + } + + return 0; } void qemu_savevm_query_pending(MigPendingData *pending, bool exact) @@ -1874,13 +1880,12 @@ static int qemu_savevm_state(QEMUFile *f, Error **errp) } ret = qemu_file_get_error(f); - if (ret == 0) { - qemu_savevm_state_complete_precopy(ms); - ret = qemu_file_get_error(f); - } - if (ret != 0) { + if (ret) { error_setg_errno(errp, -ret, "Error while writing VM state"); + goto cleanup; } + + ret = qemu_savevm_state_complete_precopy(ms, errp); cleanup: qemu_savevm_state_cleanup(); -- 2.54.0
