From patchwork Tue Mar 18 12:38:42 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Prasad Pandit X-Patchwork-Id: 14020901 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 4D8ACC28B28 for ; Tue, 18 Mar 2025 12:40:41 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1tuWEV-0002xb-3s; Tue, 18 Mar 2025 08:39:47 -0400 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 1tuWEB-0002Vo-Ie for qemu-devel@nongnu.org; Tue, 18 Mar 2025 08:39:32 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tuWE3-0007RS-Vg for qemu-devel@nongnu.org; Tue, 18 Mar 2025 08:39:26 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1742301558; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ErArQjU6eRsmzNZuSCyF39RPNl6ZM8cjudxvqH6TEE4=; b=R0seA4QG/aw29pQwwVvYVzeYQmQMDRL6zRQgd3W4ycmWkm08rKiJjtyRGM0DKd+w/gfvs/ N/dRVEKknUZJ6Wh4aCZN+OevkDA+JuixLXsSkXpjTaw8Sfi7CpaoB78Ouz5zLVFfyM698d 1M8Vf6giMhKp6hIw8bmspSRM0FCWM6E= Received: from mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-250-0TZhBk8UPM28C2zlyioUbg-1; Tue, 18 Mar 2025 08:39:14 -0400 X-MC-Unique: 0TZhBk8UPM28C2zlyioUbg-1 X-Mimecast-MFC-AGG-ID: 0TZhBk8UPM28C2zlyioUbg_1742301553 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 6DC7918009B1; Tue, 18 Mar 2025 12:39:13 +0000 (UTC) Received: from kaapi.redhat.com (unknown [10.74.16.234]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id C6E9E1800946; Tue, 18 Mar 2025 12:39:09 +0000 (UTC) From: Prasad Pandit To: qemu-devel@nongnu.org Cc: peterx@redhat.com, farosas@suse.de, berrange@redhat.com, Prasad Pandit Subject: [PATCH v8 3/7] migration: enable multifd and postcopy together Date: Tue, 18 Mar 2025 18:08:42 +0530 Message-ID: <20250318123846.1370312-4-ppandit@redhat.com> In-Reply-To: <20250318123846.1370312-1-ppandit@redhat.com> References: <20250318123846.1370312-1-ppandit@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 Received-SPF: pass client-ip=170.10.133.124; envelope-from=ppandit@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -23 X-Spam_score: -2.4 X-Spam_bar: -- X-Spam_report: (-2.4 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.332, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=0.001, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 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 From: Prasad Pandit Enable Multifd and Postcopy migration together. The migration_ioc_process_incoming() routine checks magic value sent on each channel and helps to properly setup multifd and postcopy channels. The Precopy and Multifd threads work during the initial guest RAM transfer. When migration moves to the Postcopy phase, the multifd threads cease to send data on multifd channels and Postcopy threads on the destination request/pull data from the source side. Signed-off-by: Prasad Pandit --- migration/multifd-nocomp.c | 3 ++- migration/multifd.c | 7 +++++++ migration/options.c | 5 ----- migration/ram.c | 7 +++---- 4 files changed, 12 insertions(+), 10 deletions(-) v8: - Separate this patch out from earlier patch-2. v7: - https://lore.kernel.org/qemu-devel/20250228121749.553184-1-ppandit@redhat.com/T/#t diff --git a/migration/multifd-nocomp.c b/migration/multifd-nocomp.c index ffe75256c9..02f8bf8ce8 100644 --- a/migration/multifd-nocomp.c +++ b/migration/multifd-nocomp.c @@ -17,6 +17,7 @@ #include "migration-stats.h" #include "multifd.h" #include "options.h" +#include "migration.h" #include "qapi/error.h" #include "qemu/cutils.h" #include "qemu/error-report.h" @@ -399,7 +400,7 @@ int multifd_ram_flush_and_sync(QEMUFile *f) MultiFDSyncReq req; int ret; - if (!migrate_multifd()) { + if (!migrate_multifd() || migration_in_postcopy()) { return 0; } diff --git a/migration/multifd.c b/migration/multifd.c index 6139cabe44..074d16d07d 100644 --- a/migration/multifd.c +++ b/migration/multifd.c @@ -1379,6 +1379,13 @@ static void *multifd_recv_thread(void *opaque) } if (has_data) { + /* + * multifd thread should not be active and receive data + * when migration is in the Postcopy phase. Two threads + * writing the same memory area could easily corrupt + * the guest state. + */ + assert(!migration_in_postcopy()); if (is_device_state) { assert(use_packets); ret = multifd_device_state_recv(p, &local_err); diff --git a/migration/options.c b/migration/options.c index b0ac2ea408..48aa6076de 100644 --- a/migration/options.c +++ b/migration/options.c @@ -491,11 +491,6 @@ bool migrate_caps_check(bool *old_caps, bool *new_caps, Error **errp) error_setg(errp, "Postcopy is not compatible with ignore-shared"); return false; } - - if (new_caps[MIGRATION_CAPABILITY_MULTIFD]) { - error_setg(errp, "Postcopy is not yet compatible with multifd"); - return false; - } } if (new_caps[MIGRATION_CAPABILITY_BACKGROUND_SNAPSHOT]) { diff --git a/migration/ram.c b/migration/ram.c index 424df6d9f1..6fd88cbf2a 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -1297,7 +1297,7 @@ static int find_dirty_block(RAMState *rs, PageSearchStatus *pss) pss->page = 0; pss->block = QLIST_NEXT_RCU(pss->block, next); if (!pss->block) { - if (multifd_ram_sync_per_round()) { + if (multifd_ram_sync_per_round() && !migration_in_postcopy()) { QEMUFile *f = rs->pss[RAM_CHANNEL_PRECOPY].pss_channel; int ret = multifd_ram_flush_and_sync(f); if (ret < 0) { @@ -1976,9 +1976,8 @@ static int ram_save_target_page(RAMState *rs, PageSearchStatus *pss) } } - if (migrate_multifd()) { - RAMBlock *block = pss->block; - return ram_save_multifd_page(block, offset); + if (migrate_multifd() && !migration_in_postcopy()) { + return ram_save_multifd_page(pss->block, offset); } return ram_save_page(rs, pss);