From patchwork Mon Jan 27 20:25:34 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Tokarev X-Patchwork-Id: 13952222 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 03B24C02190 for ; Tue, 28 Jan 2025 08:24:18 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1tcgf0-0002tk-QK; Tue, 28 Jan 2025 03:09:28 -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 1tcgbN-0003jt-9a; Tue, 28 Jan 2025 03:05:49 -0500 Received: from isrv.corpit.ru ([86.62.121.231]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tcgbJ-0003A5-Uo; Tue, 28 Jan 2025 03:05:40 -0500 Received: from tsrv.corpit.ru (tsrv.tls.msk.ru [192.168.177.2]) by isrv.corpit.ru (Postfix) with ESMTP id 4A1F0E1B77; Tue, 28 Jan 2025 10:57:09 +0300 (MSK) Received: from localhost.tls.msk.ru (mjt.wg.tls.msk.ru [192.168.177.130]) by tsrv.corpit.ru (Postfix) with ESMTP id BA1101A632A; Tue, 28 Jan 2025 10:57:34 +0300 (MSK) Received: by localhost.tls.msk.ru (Postfix, from userid 1000) id 3918A520E5; Tue, 28 Jan 2025 10:57:34 +0300 (MSK) To: qemu-devel@nongnu.org Cc: qemu-stable@nongnu.org, Yuan Liu , Jason Zeng , Peter Xu , Fabiano Rosas , Michael Tokarev Subject: [Stable-9.1.3 48/58] multifd: bugfix for migration using compression methods Date: Mon, 27 Jan 2025 23:25:34 +0300 Message-Id: <20250127202547.3723716-48-mjt@tls.msk.ru> X-Mailer: git-send-email 2.39.5 In-Reply-To: References: MIME-Version: 1.0 From: Michael Tokarev Received-SPF: pass client-ip=86.62.121.231; envelope-from=mjt@tls.msk.ru; helo=isrv.corpit.ru X-Spam_score_int: -53 X-Spam_score: -5.4 X-Spam_bar: ----- X-Spam_report: (-5.4 / 5.0 requ) BAYES_00=-1.9, DATE_IN_PAST_06_12=1.543, RCVD_IN_DNSWL_HI=-5, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_NONE=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 When compression is enabled on the migration channel and the pages processed are all zero pages, these pages will not be sent and updated on the target side, resulting in incorrect memory data on the source and target sides. The root cause is that all compression methods call multifd_send_prepare_common to determine whether to compress dirty pages, but multifd_send_prepare_common does not update the IOV of MultiFDPacket_t when all dirty pages are zero pages. The solution is to always update the IOV of MultiFDPacket_t regardless of whether the dirty pages are all zero pages. Fixes: 303e6f54f9 ("migration/multifd: Implement zero page transmission on the multifd thread.") Cc: qemu-stable@nongnu.org #9.0+ Signed-off-by: Yuan Liu Reviewed-by: Jason Zeng Reviewed-by: Peter Xu Message-Id: <20241218091413.140396-2-yuan1.liu@intel.com> Signed-off-by: Fabiano Rosas (cherry picked from commit cdc3970f8597ebdc1a4c2090cfb4d11e297329ed) Signed-off-by: Michael Tokarev (Mjt: in 9.1 this code is in migration/multifd.c, not in migration/multifd-nocomp.c) diff --git a/migration/multifd.c b/migration/multifd.c index a6db05502a..0b04db9f3a 100644 --- a/migration/multifd.c +++ b/migration/multifd.c @@ -1690,6 +1690,7 @@ void multifd_recv_new_channel(QIOChannel *ioc, Error **errp) bool multifd_send_prepare_common(MultiFDSendParams *p) { + multifd_send_prepare_header(p); multifd_send_zero_page_detect(p); if (!p->pages->normal_num) { @@ -1697,7 +1698,5 @@ bool multifd_send_prepare_common(MultiFDSendParams *p) return false; } - multifd_send_prepare_header(p); - return true; }