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=-7.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 1A2E1C433B4 for ; Mon, 19 Apr 2021 17:19:04 +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 88890611F2 for ; Mon, 19 Apr 2021 17:19:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 88890611F2 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]:56076 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lYXY6-00054m-HW for qemu-devel@archiver.kernel.org; Mon, 19 Apr 2021 13:19:02 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:50442) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lYXWb-0003fF-Ar for qemu-devel@nongnu.org; Mon, 19 Apr 2021 13:17:29 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:48607) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lYXWZ-0001V3-FZ for qemu-devel@nongnu.org; Mon, 19 Apr 2021 13:17:29 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1618852646; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=eAKZ9MQoHBN2UjEBQf17RiyxOdcggKK4IvUc3hiqPL8=; b=BcpDd+ZIv4HX9vXcA4uPmzyBUvxpquJyB1nNM41PVOMR3Kldxz1+6p0hhapYXYHa5kisNQ JKKzC8ZE+RUBiwJZrOkSb7N6E7v0bQ+dhUA1gd8ytct5u7NE7wgzrlL4lhV1iDszwh0VIn QGPCX9OvyzHagryNzDDD5ZpgYjOwIgw= 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-274-N5eK1w5TOwaftFDm64dDNA-1; Mon, 19 Apr 2021 13:17:25 -0400 X-MC-Unique: N5eK1w5TOwaftFDm64dDNA-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 4880D102C863 for ; Mon, 19 Apr 2021 17:17:24 +0000 (UTC) Received: from redhat.com (ovpn-114-178.ams2.redhat.com [10.36.114.178]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 81E5F5D9CC; Mon, 19 Apr 2021 17:17:22 +0000 (UTC) Date: Mon, 19 Apr 2021 18:17:19 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: "Dr. David Alan Gilbert" , Eduardo Habkost , Vitaly Kuznetsov , qemu-devel@nongnu.org, Paolo Bonzini , Juan Quintela , Markus Armbruster Subject: Re: [PATCH RFC] migration: warn about non-migratable configurations unless '--no-migration' was specified Message-ID: References: <20210415154402.28424-1-vkuznets@redhat.com> <874kg68z07.fsf@vitty.brq.redhat.com> <20210416162801.zluqlbvyipoanedw@habkost.net> MIME-Version: 1.0 In-Reply-To: User-Agent: Mutt/2.0.5 (2021-01-21) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 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 Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=170.10.133.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, 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: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Mon, Apr 19, 2021 at 06:15:56PM +0100, Daniel P. Berrangé wrote: > On Mon, Apr 19, 2021 at 06:11:47PM +0100, Dr. David Alan Gilbert wrote: > > * Eduardo Habkost (ehabkost@redhat.com) wrote: > > > I would make live migration policy an enum, just to make sure > > > we are explicit about the requirements: > > > > > > - UNKNOWN: this is the current state in QEMU 6.0, where we don't > > > really know what the user expects. > > > This can be the default on existing versioned machine types, > > > just for compatibility. > > > I suggest making this print warnings for every migration > > > blocker (like this patch does). > > > I suggest deprecating this behavior as soon as we can. > > > > > > - PREFERRED: try to make the VM migratable when possible, but > > > don't print a warning or error out if migration is blocked. > > > This seems to be the behavior expected by libvirt today. > > > > > > - NOT_NEEDED: live migration is not needed, and QEMU is free to > > > enable features that block live migration or change guest ABI. > > > We can probably make this the default on machine types that > > > never supported live migration. > > > > I suggest you could do this by adding: > > -warn-none-migratable > > -no-warn-none-migratable > > > > and then argue about defaults another time. > > If we're going to add new args, lets at least future proof our > approach with an extensible option that we can wire into QMP > too later > > -migratable none|preferred|required > > and letting us add extra key/value pairs to tune it if desired. Having said that, we potentially don't need a dedicated arg if we just make 'migratable=none|preferred|required' be a property of the machine type and hook everything off that > > > > - REQUIRED: live migration is required, and adding a migration > > > blocker would be a fatal error. > > > This is already implemented by --only-migratable. > > > I suggest making this the default on versioned machine types > > > after a few releases, and after deprecating UNKNOWN. 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 :|