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 42951C43462 for ; Thu, 15 Apr 2021 16:08:32 +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 B8A1D610F7 for ; Thu, 15 Apr 2021 16:08:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B8A1D610F7 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]:32818 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lX4Xe-0005Mx-JF for qemu-devel@archiver.kernel.org; Thu, 15 Apr 2021 12:08:30 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:33020) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lX4Tk-0002JU-9v for qemu-devel@nongnu.org; Thu, 15 Apr 2021 12:04:28 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:52967) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lX4Th-000137-U2 for qemu-devel@nongnu.org; Thu, 15 Apr 2021 12:04:27 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1618502665; 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=pr0Garrs95FpJMcGKKxXEef8NWB03hN4mxkp2JzawKg=; b=EUDKlf3K1+ZZBVoguqaOguksEHYD1seEYyunbTQJYZExaNA5z+08LvhbZZGNl4lf0gaDRi gNVf9n6pF6oTnwZHNsgTMmRi1PgF5DnGCDpGW9aCoxX4ffyo4wUJtKb9mAthNAje82LdRp 2h0JQfXLf+WiDYWkGjDDxlfsZ4wmQTU= 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-501-EiaFpxA3PJaXaSJZgDXVNg-1; Thu, 15 Apr 2021 12:04:19 -0400 X-MC-Unique: EiaFpxA3PJaXaSJZgDXVNg-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 55075814256 for ; Thu, 15 Apr 2021 16:04:18 +0000 (UTC) Received: from redhat.com (ovpn-115-159.ams2.redhat.com [10.36.115.159]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 831D910016DB; Thu, 15 Apr 2021 16:04:16 +0000 (UTC) Date: Thu, 15 Apr 2021 17:04:13 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Vitaly Kuznetsov 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: <20210415154402.28424-1-vkuznets@redhat.com> User-Agent: Mutt/2.0.5 (2021-01-21) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 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: -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: Eduardo Habkost , Juan Quintela , qemu-devel@nongnu.org, Markus Armbruster , "Dr . David Alan Gilbert" , Paolo Bonzini Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" 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 ? 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 :|