From patchwork Tue Dec 5 06:52:52 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Xu X-Patchwork-Id: 844596 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=2001:4830:134:3::11; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3yrXbk6sXnz9sBZ for ; Tue, 5 Dec 2017 17:56:50 +1100 (AEDT) Received: from localhost ([::1]:46838 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eM79t-0001vb-2g for incoming@patchwork.ozlabs.org; Tue, 05 Dec 2017 01:56:49 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51192) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eM77D-0008Oo-2O for qemu-devel@nongnu.org; Tue, 05 Dec 2017 01:54:04 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eM779-0003fu-PW for qemu-devel@nongnu.org; Tue, 05 Dec 2017 01:54:03 -0500 Received: from mx1.redhat.com ([209.132.183.28]:51402) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1eM779-0003fO-HG for qemu-devel@nongnu.org; Tue, 05 Dec 2017 01:53:59 -0500 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 9D0D181DF5; Tue, 5 Dec 2017 06:53:58 +0000 (UTC) Received: from xz-mi.nay.redhat.com (dhcp-14-111.nay.redhat.com [10.66.14.111]) by smtp.corp.redhat.com (Postfix) with ESMTP id 396F562461; Tue, 5 Dec 2017 06:53:55 +0000 (UTC) From: Peter Xu To: qemu-devel@nongnu.org Date: Tue, 5 Dec 2017 14:52:52 +0800 Message-Id: <20171205065307.21853-14-peterx@redhat.com> In-Reply-To: <20171205065307.21853-1-peterx@redhat.com> References: <20171205065307.21853-1-peterx@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.25]); Tue, 05 Dec 2017 06:53:58 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v5 13/28] migration: new state "postcopy-recover" X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Andrea Arcangeli , Juan Quintela , Alexey Perevalov , peterx@redhat.com, "Dr . David Alan Gilbert" Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" Introducing new migration state "postcopy-recover". If a migration procedure is paused and the connection is rebuilt afterward successfully, we'll switch the source VM state from "postcopy-paused" to the new state "postcopy-recover", then we'll do the resume logic in the migration thread (along with the return path thread). This patch only do the state switch on source side. Another following up patch will handle the state switching on destination side using the same status bit. Reviewed-by: Dr. David Alan Gilbert Signed-off-by: Peter Xu --- migration/migration.c | 76 ++++++++++++++++++++++++++++++++++++++------------- qapi/migration.json | 4 ++- 2 files changed, 60 insertions(+), 20 deletions(-) diff --git a/migration/migration.c b/migration/migration.c index a061691fe5..e00f4d0ad0 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -554,6 +554,7 @@ static bool migration_is_setup_or_active(int state) case MIGRATION_STATUS_ACTIVE: case MIGRATION_STATUS_POSTCOPY_ACTIVE: case MIGRATION_STATUS_POSTCOPY_PAUSED: + case MIGRATION_STATUS_POSTCOPY_RECOVER: case MIGRATION_STATUS_SETUP: case MIGRATION_STATUS_PRE_SWITCHOVER: case MIGRATION_STATUS_DEVICE: @@ -634,6 +635,7 @@ MigrationInfo *qmp_query_migrate(Error **errp) case MIGRATION_STATUS_PRE_SWITCHOVER: case MIGRATION_STATUS_DEVICE: case MIGRATION_STATUS_POSTCOPY_PAUSED: + case MIGRATION_STATUS_POSTCOPY_RECOVER: /* TODO add some postcopy stats */ info->has_status = true; info->has_total_time = true; @@ -2250,6 +2252,13 @@ typedef enum MigThrError { MIG_THR_ERR_FATAL = 2, } MigThrError; +/* Return zero if success, or <0 for error */ +static int postcopy_do_resume(MigrationState *s) +{ + /* TODO: do the resume logic */ + return 0; +} + /* * We don't return until we are in a safe state to continue current * postcopy migration. Returns MIG_THR_ERR_RECOVERED if recovered, or @@ -2258,29 +2267,55 @@ typedef enum MigThrError { 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; + while (true) { + migrate_set_state(&s->state, s->state, + MIGRATION_STATUS_POSTCOPY_PAUSED); - error_report("Detected IO failure for postcopy. " - "Migration 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; - /* - * 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); - } + 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(); + if (s->state == MIGRATION_STATUS_POSTCOPY_RECOVER) { + /* Woken up by a recover procedure. Give it a shot */ + + /* + * Firstly, let's wake up the return path now, with a new + * return path channel. + */ + qemu_sem_post(&s->postcopy_pause_rp_sem); - return MIG_THR_ERR_RECOVERED; + /* Do the resume logic */ + if (postcopy_do_resume(s) == 0) { + /* Let's continue! */ + trace_postcopy_pause_continued(); + return MIG_THR_ERR_RECOVERED; + } else { + /* + * Something wrong happened during the recovery, let's + * pause again. Pause is always better than throwing + * data away. + */ + continue; + } + } else { + /* This is not right... Time to quit. */ + return MIG_THR_ERR_FATAL; + } + } } static MigThrError migration_detect_error(MigrationState *s) @@ -2545,7 +2580,10 @@ void migrate_fd_connect(MigrationState *s) } if (resume) { - /* TODO: do the resume logic */ + /* Wakeup the main migration thread to do the recovery */ + migrate_set_state(&s->state, MIGRATION_STATUS_POSTCOPY_PAUSED, + MIGRATION_STATUS_POSTCOPY_RECOVER); + qemu_sem_post(&s->postcopy_pause_sem); return; } diff --git a/qapi/migration.json b/qapi/migration.json index 2ea12fcad4..5dfac0681d 100644 --- a/qapi/migration.json +++ b/qapi/migration.json @@ -91,6 +91,8 @@ # # @postcopy-paused: during postcopy but paused. (since 2.12) # +# @postcopy-recover: trying to recover from a paused postcopy. (since 2.11) +# # @completed: migration is finished. # # @failed: some error occurred during migration process. @@ -109,7 +111,7 @@ { 'enum': 'MigrationStatus', 'data': [ 'none', 'setup', 'cancelling', 'cancelled', 'active', 'postcopy-active', 'postcopy-paused', - 'completed', 'failed', 'colo', + 'postcopy-recover', 'completed', 'failed', 'colo', 'pre-switchover', 'device' ] } ##