From patchwork Fri Jan 10 12:13:57 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fabiano Rosas X-Patchwork-Id: 13934386 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 270E7E77188 for ; Fri, 10 Jan 2025 12:19:40 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1tWDuO-0001Qu-2g; Fri, 10 Jan 2025 07:14:36 -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 1tWDuM-0001QU-BH; Fri, 10 Jan 2025 07:14:34 -0500 Received: from smtp-out2.suse.de ([195.135.223.131]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1tWDuK-0003Kc-Hz; Fri, 10 Jan 2025 07:14:34 -0500 Received: from imap1.dmz-prg2.suse.org (unknown [10.150.64.97]) (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 smtp-out2.suse.de (Postfix) with ESMTPS id C0C9C1F396; Fri, 10 Jan 2025 12:14:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1736511270; h=from:from:reply-to: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=IGIX6eUopLSHhRjZ/6kJyKQKELSW97bPyG9/vdYLRjs=; b=VHelm+b3zFchBfe9Xfp75FNBRIfXCAFLfUqM0ZHLX4ySK7cnVSOd1FvsyLMfxeflafxISQ EYnPHpkV6qdI+Oxq1ks2L5/Zebttm8K5Ht/SzMd/kMGmPlBatBI5+rWRGSgppwr1UprQPs m+irrVwDCywU0sDK2B8/AOUH1uZaeGA= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1736511270; h=from:from:reply-to: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=IGIX6eUopLSHhRjZ/6kJyKQKELSW97bPyG9/vdYLRjs=; b=B7Q8usH30kScucf5lyoJbCce8NZBSwC33zTJhfq2koQqYNYzpC2j4pf+9SG3+4ArtvfB3C ARjFQh+MaH3Kv9CQ== Authentication-Results: smtp-out2.suse.de; none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1736511270; h=from:from:reply-to: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=IGIX6eUopLSHhRjZ/6kJyKQKELSW97bPyG9/vdYLRjs=; b=VHelm+b3zFchBfe9Xfp75FNBRIfXCAFLfUqM0ZHLX4ySK7cnVSOd1FvsyLMfxeflafxISQ EYnPHpkV6qdI+Oxq1ks2L5/Zebttm8K5Ht/SzMd/kMGmPlBatBI5+rWRGSgppwr1UprQPs m+irrVwDCywU0sDK2B8/AOUH1uZaeGA= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1736511270; h=from:from:reply-to: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=IGIX6eUopLSHhRjZ/6kJyKQKELSW97bPyG9/vdYLRjs=; b=B7Q8usH30kScucf5lyoJbCce8NZBSwC33zTJhfq2koQqYNYzpC2j4pf+9SG3+4ArtvfB3C ARjFQh+MaH3Kv9CQ== Received: from imap1.dmz-prg2.suse.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 imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id 8523C13A86; Fri, 10 Jan 2025 12:14:29 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id cLGeEiUPgWdURwAAD6G6ig (envelope-from ); Fri, 10 Jan 2025 12:14:29 +0000 From: Fabiano Rosas To: qemu-devel@nongnu.org Cc: Peter Xu , qemu-stable@nongnu.org Subject: [PULL 09/25] migration/multifd: Fix compat with QEMU < 9.0 Date: Fri, 10 Jan 2025 09:13:57 -0300 Message-Id: <20250110121413.12336-10-farosas@suse.de> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20250110121413.12336-1-farosas@suse.de> References: <20250110121413.12336-1-farosas@suse.de> MIME-Version: 1.0 X-Spamd-Result: default: False [-2.80 / 50.00]; BAYES_HAM(-3.00)[99.99%]; MID_CONTAINS_FROM(1.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000]; R_MISSING_CHARSET(0.50)[]; NEURAL_HAM_SHORT(-0.20)[-1.000]; MIME_GOOD(-0.10)[text/plain]; MIME_TRACE(0.00)[0:+]; TO_DN_SOME(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; ARC_NA(0.00)[]; DKIM_SIGNED(0.00)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; FUZZY_BLOCKED(0.00)[rspamd.com]; FROM_EQ_ENVFROM(0.00)[]; FROM_HAS_DN(0.00)[]; RCPT_COUNT_THREE(0.00)[3]; RCVD_COUNT_TWO(0.00)[2]; TO_MATCH_ENVRCPT_ALL(0.00)[]; DBL_BLOCKED_OPENRESOLVER(0.00)[suse.de:email,suse.de:mid]; RCVD_TLS_ALL(0.00)[] Received-SPF: pass client-ip=195.135.223.131; envelope-from=farosas@suse.de; helo=smtp-out2.suse.de X-Spam_score_int: -43 X-Spam_score: -4.4 X-Spam_bar: ---- X-Spam_report: (-4.4 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_MED=-2.3, 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 Commit f5f48a7891 ("migration/multifd: Separate SYNC request with normal jobs") changed the multifd source side to stop sending data along with the MULTIFD_FLAG_SYNC, effectively introducing the concept of a SYNC-only packet. Relying on that, commit d7e58f412c ("migration/multifd: Don't send ram data during SYNC") later came along and skipped reading data from SYNC packets. In a versions timeline like this: 8.2 f5f48a7 9.0 9.1 d7e58f41 9.2 The issue arises that QEMUs < 9.0 still send data along with SYNC, but QEMUs > 9.1 don't gather that data anymore. This leads to various kinds of migration failures due to desync/missing data. Stop checking for a SYNC packet on the destination and unconditionally unfill the packet. >From now on: old -> new: the source sends data + sync, destination reads normally new -> new: source sends only sync, destination reads zeros new -> old: source sends only sync, destination reads zeros CC: qemu-stable@nongnu.org Fixes: d7e58f412c ("migration/multifd: Don't send ram data during SYNC") Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2720 Reviewed-by: Peter Xu Signed-off-by: Fabiano Rosas Message-Id: <20241213160120.23880-2-farosas@suse.de> Signed-off-by: Fabiano Rosas --- migration/multifd.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/migration/multifd.c b/migration/multifd.c index 64e0ac2488..ab73d6d984 100644 --- a/migration/multifd.c +++ b/migration/multifd.c @@ -252,9 +252,8 @@ static int multifd_recv_unfill_packet(MultiFDRecvParams *p, Error **errp) p->packet_num = be64_to_cpu(packet->packet_num); p->packets_recved++; - if (!(p->flags & MULTIFD_FLAG_SYNC)) { - ret = multifd_ram_unfill_packet(p, errp); - } + /* Always unfill, old QEMUs (<9.0) send data along with SYNC */ + ret = multifd_ram_unfill_packet(p, errp); trace_multifd_recv_unfill(p->id, p->packet_num, p->flags, p->next_packet_size); @@ -1156,9 +1155,13 @@ static void *multifd_recv_thread(void *opaque) flags = p->flags; /* recv methods don't know how to handle the SYNC flag */ p->flags &= ~MULTIFD_FLAG_SYNC; - if (!(flags & MULTIFD_FLAG_SYNC)) { - has_data = p->normal_num || p->zero_num; - } + + /* + * Even if it's a SYNC packet, this needs to be set + * because older QEMUs (<9.0) still send data along with + * the SYNC packet. + */ + has_data = p->normal_num || p->zero_num; qemu_mutex_unlock(&p->mutex); } else { /*