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=-5.0 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,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 2EBA2C433ED for ; Mon, 19 Apr 2021 16:40:21 +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 81C7561026 for ; Mon, 19 Apr 2021 16:40:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 81C7561026 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]:38958 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lYWwc-0006JR-Bv for qemu-devel@archiver.kernel.org; Mon, 19 Apr 2021 12:40:18 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:41870) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lYWuR-0005ka-KP for qemu-devel@nongnu.org; Mon, 19 Apr 2021 12:38:03 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:55746) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lYWuP-0000Tn-C3 for qemu-devel@nongnu.org; Mon, 19 Apr 2021 12:38:03 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1618850280; 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=UbwCOBrFfsbb2MbirR/wq1HGS/K+uZ/TSzlOdNhP+4k=; b=RPg5lGBXtDrwjymkL0l9Blskh751DN2S0yuxH+HlTu4VVewK7UcJT+cZTzfxtdZPQfLVDK iejlxv9iDVlZ/ERr01eJBjfa44pwHNmJDsvMoG5/JrQQtbLEOE9+oyB4Yp8Vgg3Ru+Qk4l VWYELS+H/zvf7gNcOdpAOrMd0Y93Uik= 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-16-dFOTPen_Oi-MVrHO7ZrhMg-1; Mon, 19 Apr 2021 12:37:59 -0400 X-MC-Unique: dFOTPen_Oi-MVrHO7ZrhMg-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 205FF100807F; Mon, 19 Apr 2021 16:37:37 +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 2BBC760C04; Mon, 19 Apr 2021 16:37:34 +0000 (UTC) Date: Mon, 19 Apr 2021 17:37:32 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Eduardo Habkost Subject: Re: [PATCH RFC] migration: warn about non-migratable configurations unless '--no-migration' was specified Message-ID: References: <20210415154402.28424-1-vkuznets@redhat.com> MIME-Version: 1.0 In-Reply-To: User-Agent: Mutt/2.0.5 (2021-01-21) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 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=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?= Cc: Peter Maydell , Juan Quintela , QEMU Developers , Markus Armbruster , Paolo Bonzini , Vitaly Kuznetsov , "Dr . David Alan Gilbert" Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Mon, Apr 19, 2021 at 12:28:04PM -0400, Eduardo Habkost wrote: > On Sun, Apr 18, 2021 at 11:54 AM Peter Maydell wrote: > > > > On Thu, 15 Apr 2021 at 16:46, Vitaly Kuznetsov wrote: > > > When a migration blocker is added nothing is reported to the user, > > > inability to migrate such guest may come as a late surprise. As a bare > > > minimum, we can print a warning. To not pollute the output for those, who > > > have no intention to migrate their guests, introduce '--no-migration' > > > option which both block the migration and eliminates warning from > > > > I'm not a fan. For a lot of people and configurations this > > is going to be "add an extra complaint from QEMU to a previously > > working configuration". We add too many of those already. > > I agree that warning with machine types that never supported live > migration would be useless noise, but warning if using an explicit > versioned machine type sounds like a reasonable default (as long as > the warnings includes clear instructions on how to silence them). Libvirt will always expand a machine type alias into a versioned machine type, because stable ABI is useful even if never migrating, because it ensures the guest OS doesn't see hardware changes that may trigger license re-activation At the same time a large portion of users will never care about live migration/save/restore, or they do care but will hotunplug the problems devices before attempting a migration. IMHO tieing messages to versioned machine types is not desirable as a strategy by default. Warning about migration compatibility should be an explicit opt-in 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 :|