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 56010C433B4 for ; Thu, 15 Apr 2021 17:34:54 +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 E9B15610FA for ; Thu, 15 Apr 2021 17:34:53 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E9B15610FA 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]:55854 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lX5tF-0002qG-45 for qemu-devel@archiver.kernel.org; Thu, 15 Apr 2021 13:34:53 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:59950) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lX5nB-0006sv-Sn for qemu-devel@nongnu.org; Thu, 15 Apr 2021 13:28:37 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:20361) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lX5n8-0004Yx-4h for qemu-devel@nongnu.org; Thu, 15 Apr 2021 13:28:37 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1618507712; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=rcApZE0SGWlNoH72nYWyCTpBAeYOVUlkwn2ld/FmZ/Y=; b=c5gkhA/yioAV6JTMr9idjRo3ijHkhg+2iHgw7CK7OIgOyPGwW2Bf36SM5x9iJIoPc62bW2 1An5E0uY94hnj2IgTNZMWAJtscHQT6Dt9PiXTQwxJrd73sXTO/PFHJOz5zKjWmgRuoJ3IX aAJyPMEJ2AEH6AuVF3qJD7CbOu45L84= 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-307-5reqB7nTNzufFdUMuU0tMw-1; Thu, 15 Apr 2021 13:28:29 -0400 X-MC-Unique: 5reqB7nTNzufFdUMuU0tMw-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 2096D6D582 for ; Thu, 15 Apr 2021 17:28:28 +0000 (UTC) Received: from work-vm (ovpn-113-195.ams2.redhat.com [10.36.113.195]) by smtp.corp.redhat.com (Postfix) with ESMTPS id C5BC4610A8; Thu, 15 Apr 2021 17:28:24 +0000 (UTC) Date: Thu, 15 Apr 2021 18:28:22 +0100 From: "Dr. David Alan Gilbert" To: Daniel =?iso-8859-1?Q?P=2E_Berrang=E9?= 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/2.0.6 (2021-03-06) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 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=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=216.205.24.124; envelope-from=dgilbert@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: , Cc: Eduardo Habkost , Juan Quintela , Markus Armbruster , qemu-devel@nongnu.org, Paolo Bonzini , Vitaly Kuznetsov Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" * Daniel P. Berrangé (berrange@redhat.com) wrote: > On Thu, Apr 15, 2021 at 05:44:02PM +0200, 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 wonder how this is actually going to work in practice ? > > At the time libvirt starts a guest, it has no idea whether the guest > is likely to need migration 3, 6, 12, 24 months in to the future. > > IOW, we can't use a --no-migration flag and will be stuck with these > warnings no mtter what. > > Is it possible to query the migration blockers via QMP ? It's possible to query the currently active ones, as of 6.0; from my commit 3af8554bd068576b0399087583df48518a2a98f6 it appears in the output of query-migrate in the 'blocked-reasons' list. The HMP equivalent is a64aec725ea0b26fa4e44f8b8b8c72be9aaa4230 showing: (qemu) info migrate globals: store-global-state: on only-migratable: off send-configuration: on send-section-footer: on decompress-error-check: on clear-bitmap-shift: 18 Outgoing migration blocked: Migration is disabled when VirtFS export path '/home' is mounted in the guest using mount_tag 'fs' non-migratable device: 0000:00:01.2/1/usb-serial Dave > Libvirt recently introduced a new API 'virDomainGetMessages' which > lets us report a list of human targetted message strings against > a guest. We use it for reporting when an operation has tainted > a guest, and also use it for reporting when a deprecated QEMU > feature is used. We could use it to report any migration > blockers that exist. > > These are visible from 'virsh dominfo $guestname' and could also > be displayed by a mgmt application. > > NB, the messages are intentionally declared opaque strings, so > mgmt apps shouldn't try to parse them. They merely know whether > the count is non-zero for any given message class. > > > 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 :| -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK