From patchwork Wed Mar 6 13:34:25 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?C=C3=A9dric_Le_Goater?= X-Patchwork-Id: 13584082 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 6D36EC5475B for ; Wed, 6 Mar 2024 13:38:01 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rhrQo-0008JO-Fc; Wed, 06 Mar 2024 08:35:38 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rhrQk-0008IX-3D for qemu-devel@nongnu.org; Wed, 06 Mar 2024 08:35:34 -0500 Received: from mail.ozlabs.org ([2404:9400:2221:ea00::3] helo=gandalf.ozlabs.org) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rhrQi-0005ZV-38 for qemu-devel@nongnu.org; Wed, 06 Mar 2024 08:35:33 -0500 Received: from gandalf.ozlabs.org (gandalf.ozlabs.org [150.107.74.76]) by gandalf.ozlabs.org (Postfix) with ESMTP id 4TqYN20v6Nz4wyk; Thu, 7 Mar 2024 00:35:30 +1100 (AEDT) Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mail.ozlabs.org (Postfix) with ESMTPSA id 4TqYMy6d6Jz4wcF; Thu, 7 Mar 2024 00:35:26 +1100 (AEDT) From: =?utf-8?q?C=C3=A9dric_Le_Goater?= To: qemu-devel@nongnu.org Cc: Peter Xu , Fabiano Rosas , Alex Williamson , Avihai Horon , =?utf-8?q?Philippe_Mathieu-Daud=C3=A9?= , Markus Armbruster , Prasad Pandit , =?utf-8?q?C=C3=A9dric_Le_Goater?= Subject: [PATCH v4 10/25] migration: Add Error** argument to qemu_savevm_state_setup() Date: Wed, 6 Mar 2024 14:34:25 +0100 Message-ID: <20240306133441.2351700-11-clg@redhat.com> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240306133441.2351700-1-clg@redhat.com> References: <20240306133441.2351700-1-clg@redhat.com> MIME-Version: 1.0 Received-SPF: pass client-ip=2404:9400:2221:ea00::3; envelope-from=SRS0=yBjJ=KM=redhat.com=clg@ozlabs.org; helo=gandalf.ozlabs.org X-Spam_score_int: -39 X-Spam_score: -4.0 X-Spam_bar: ---- X-Spam_report: (-4.0 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.25, RCVD_IN_DNSWL_MED=-2.3, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org 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. In qemu_savevm_state(), move the cleanup to preserve the error reported by .save_setup() handlers. 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 Reviewed-by: Fabiano Rosas Signed-off-by: Cédric Le Goater --- Changes in v4: - Merged cleanup change in qemu_savevm_state() 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 | 26 +++++++++++++++----------- 3 files changed, 40 insertions(+), 15 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 a49fcd53ee19df1ce0182bc99d7e064968f0317b..6d1544224e96f5edfe56939a9c8395d88ef29581 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -3408,6 +3408,8 @@ 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()); @@ -3451,9 +3453,17 @@ 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); @@ -3530,6 +3540,9 @@ 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)); @@ -3563,9 +3576,16 @@ 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); @@ -3632,7 +3652,8 @@ 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 ee31ffb5e88cea723039c754c30ce2c8a0ef35f3..63fdbb5ad7d4dbfaef1d2094350bf302cc677602 100644 --- a/migration/savevm.c +++ b/migration/savevm.c @@ -1310,11 +1310,11 @@ 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()); @@ -1323,10 +1323,9 @@ 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; } @@ -1346,18 +1345,19 @@ 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) @@ -1728,7 +1728,10 @@ 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) { @@ -1741,10 +1744,11 @@ static int qemu_savevm_state(QEMUFile *f, Error **errp) qemu_savevm_state_complete_precopy(f, false, false); ret = qemu_file_get_error(f); } - qemu_savevm_state_cleanup(); if (ret != 0) { error_setg_errno(errp, -ret, "Error while writing VM state"); } +cleanup: + qemu_savevm_state_cleanup(); if (ret != 0) { status = MIGRATION_STATUS_FAILED;