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=-15.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 CA344C433DB for ; Thu, 11 Mar 2021 09:43:37 +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 E251864ED0 for ; Thu, 11 Mar 2021 09:43:36 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E251864ED0 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]:38178 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lKHqx-00065o-Kq for qemu-devel@archiver.kernel.org; Thu, 11 Mar 2021 04:43:35 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:57434) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lKHoe-0003zz-SC for qemu-devel@nongnu.org; Thu, 11 Mar 2021 04:41:13 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:43396) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1lKHoa-0005dn-Ax for qemu-devel@nongnu.org; Thu, 11 Mar 2021 04:41:11 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1615455666; h=from:from:reply-to: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=Y5SoJT8iDhNIm/NRHvrr1gM4tOupNO9rJYa4LwpFZKM=; b=g5Ob3tjrAKlih0MKwpeIruMTgjB1XP5Li5N6z+45A6i1mN1Sw9daCLvRfi39zDBWMI8WMc FyDvL9L4iNwAkHAbIE0bE4ySrmRgxD3utO7V1UeCIhQSnvArnsV9//2HX64DsmchEHsja2 OysCXfydRNJi7clceXbVHcf7Jo4qBAQ= 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-169-dyd1bK2wMGWi4jAtHoC1rg-1; Thu, 11 Mar 2021 04:40:54 -0500 X-MC-Unique: dyd1bK2wMGWi4jAtHoC1rg-1 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 mimecast-mx01.redhat.com (Postfix) with ESMTPS id 1E04283DD25; Thu, 11 Mar 2021 09:40:52 +0000 (UTC) Received: from redhat.com (ovpn-115-85.ams2.redhat.com [10.36.115.85]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 2355D69321; Thu, 11 Mar 2021 09:40:44 +0000 (UTC) Date: Thu, 11 Mar 2021 09:40:42 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Tarun Gupta Subject: Re: [PATCH v2 1/1] docs/devel: Add VFIO device migration documentation Message-ID: References: <20210310192009.53848-1-targupta@nvidia.com> MIME-Version: 1.0 In-Reply-To: <20210310192009.53848-1-targupta@nvidia.com> User-Agent: Mutt/2.0.5 (2021-01-21) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=berrange@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Received-SPF: pass client-ip=216.205.24.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -29 X-Spam_score: -3.0 X-Spam_bar: --- X-Spam_report: (-3.0 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.243, 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_H3=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: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Cc: kevin.tian@intel.com, cjia@nvidia.com, quintela@redhat.com, cohuck@redhat.com, qemu-devel@nongnu.org, Kirti Wankhede , dgilbert@redhat.com, lushenming@huawei.com, alex.williamson@redhat.com, dnigam@nvidia.com, yan.y.zhao@intel.com, philmd@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Thu, Mar 11, 2021 at 12:50:09AM +0530, Tarun Gupta wrote: > Document interfaces used for VFIO device migration. Added flow of state changes > during live migration with VFIO device. Tested by building docs with the new > vfio-migration.rst file. > > v2: > - Included the new vfio-migration.rst file in index.rst > - Updated dirty page tracking section, also added details about > 'pre-copy-dirty-page-tracking' opt-out option. > - Incorporated comments around wording of doc. > > Signed-off-by: Tarun Gupta > Signed-off-by: Kirti Wankhede > --- > MAINTAINERS | 1 + > docs/devel/index.rst | 1 + > docs/devel/vfio-migration.rst | 135 ++++++++++++++++++++++++++++++++++ > 3 files changed, 137 insertions(+) > create mode 100644 docs/devel/vfio-migration.rst > +Postcopy > +======== > + > +Postcopy migration is not supported for VFIO devices. What is the problem here and is there any plan for how to address it ? Postcopy is essentially the only migration mechanism that can reliably complete, so it really should be considered the default approach to migration for all mgmt apps wanting to do migration, except in special cases. IOW, if we want VFIO migration to be viable, we need postcopy support. Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|