From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5B77BC433B4 for ; Thu, 6 May 2021 13:07:50 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id D16C1610EA for ; Thu, 6 May 2021 13:07:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D16C1610EA Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:51232 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ledjI-0001Cl-FO for qemu-devel@archiver.kernel.org; Thu, 06 May 2021 09:07:48 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:47834) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ledhl-0000a0-0n for qemu-devel@nongnu.org; Thu, 06 May 2021 09:06:16 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:46187) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ledhg-0003ly-7X for qemu-devel@nongnu.org; Thu, 06 May 2021 09:06:11 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1620306364; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=q5q1nuCGKBKnd2ChWQiK2d796I7OGJxR0DIhcPSP7Wk=; b=OE9FKWU2DgtMCnMNevod4XDTZPu5pU1mjeC6tfAI+ZvxO+/o1wMr0Mc4rNjNT+r8zCSOlt AJ3jwTJE5DouD7gV5qtp9nw0K4v+LFTU0gZZ7mt5qk7lLNs7FGTWxfxZZz99cT9XXh7U98 AhDuMc4XHdG09IBzMDQaDRDuRqXkl2Y= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-226-ZrH5xdVROZyABmsVWFwzwA-1; Thu, 06 May 2021 09:06:01 -0400 X-MC-Unique: ZrH5xdVROZyABmsVWFwzwA-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id CB4081800D50; Thu, 6 May 2021 13:05:59 +0000 (UTC) Received: from work-vm (ovpn-115-37.ams2.redhat.com [10.36.115.37]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 901F65D9DE; Thu, 6 May 2021 13:05:54 +0000 (UTC) Date: Thu, 6 May 2021 14:05:51 +0100 From: "Dr. David Alan Gilbert" To: Kunkun Jiang Subject: Re: [question] The source cannot recover, if the destination fails in the last round of live migration Message-ID: References: <7d87a3b7-86c9-9248-59dc-e1612a00e7c3@huawei.com> MIME-Version: 1.0 In-Reply-To: <7d87a3b7-86c9-9248-59dc-e1612a00e7c3@huawei.com> User-Agent: Mutt/2.0.6 (2021-03-06) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dgilbert@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Received-SPF: pass client-ip=170.10.133.124; envelope-from=dgilbert@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -34 X-Spam_score: -3.5 X-Spam_bar: --- X-Spam_report: (-3.5 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.69, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=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: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: David Edmondson , Juan Quintela , "open list:All patches CC here" , Peter Xu , Zenghui Yu , wanghaibin.wang@huawei.com, Keqian Zhu Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" * Kunkun Jiang (jiangkunkun@huawei.com) wrote: > Hi all, Hi, > Recently I am learning about the part of live migration. > I have a question about the last round. > > When the pending_size is less than the threshold, it will enter > the last round and call migration_completion(). It will stop the > source and sent the remaining dirty pages and devices' status > information to the destination. The destination will load these > information and start the VM. > > If there is an error at the destination at this time, it will exit > directly, and the source will not be able to detect the error > and recover. Because the source will not call > migration_detect_error(). > > Is my understanding correct? > Should the source wait the result of the last round of destination ? Try setting the 'return-path' migration capability on both the source and destination; I think it's that option will cause the destination to send an OK/error at the end and the source to wait for it. Dave > Thanks, > Kunkun Jiang > > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK