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=-0.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 19AEBC3A59E for ; Fri, 16 Aug 2019 12:24:19 +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 A753E2064A for ; Fri, 16 Aug 2019 12:24:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A753E2064A 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]:55140 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1hybHF-0001IR-JU for qemu-devel@archiver.kernel.org; Fri, 16 Aug 2019 08:24:17 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:56886) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1hybGB-0000hF-VB for qemu-devel@nongnu.org; Fri, 16 Aug 2019 08:23:12 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hybG9-0005xq-UG for qemu-devel@nongnu.org; Fri, 16 Aug 2019 08:23:10 -0400 Received: from mx1.redhat.com ([209.132.183.28]:52754) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hybG9-0005xK-PR for qemu-devel@nongnu.org; Fri, 16 Aug 2019 08:23:09 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id AA446C04FFE0; Fri, 16 Aug 2019 12:23:08 +0000 (UTC) Received: from blackfin.pond.sub.org (ovpn-117-142.ams2.redhat.com [10.36.117.142]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 215517DA53; Fri, 16 Aug 2019 12:23:04 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 67EAC10E6CCA; Fri, 16 Aug 2019 14:22:58 +0200 (CEST) From: Markus Armbruster To: Erik Skultety References: <20190815183803.13346-1-ehabkost@redhat.com> <20190815183803.13346-4-ehabkost@redhat.com> <87pnl5sks3.fsf@dusky.pond.sub.org> <20190816074932.GK13569@beluga.usersys.redhat.com> Date: Fri, 16 Aug 2019 14:22:58 +0200 In-Reply-To: <20190816074932.GK13569@beluga.usersys.redhat.com> (Erik Skultety's message of "Fri, 16 Aug 2019 09:49:32 +0200") Message-ID: <87h86hpae5.fsf@dusky.pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.31]); Fri, 16 Aug 2019 12:23:08 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: Re: [Qemu-devel] [PATCH 3/3] pc: Don't make CPU properties mandatory unless necessary 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: Peter Krempa , Eduardo Habkost , Like Xu , "Michael S. Tsirkin" , qemu-devel@nongnu.org, Paolo Bonzini , Igor Mammedov , Richard Henderson Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Erik Skultety writes: > On Fri, Aug 16, 2019 at 08:10:20AM +0200, Markus Armbruster wrote: >> Eduardo Habkost writes: >> >> > We have this issue reported when using libvirt to hotplug CPUs: >> > https://bugzilla.redhat.com/show_bug.cgi?id=1741451 >> > >> > Basically, libvirt is not copying die-id from >> > query-hotpluggable-cpus, but die-id is now mandatory. >> >> Uh-oh, "is now mandatory": making an optional property mandatory is an >> incompatible change. When did we do that? Commit hash, please. >> >> [...] >> > > I don't even see it as being optional ever - the property wasn't even > recognized before commit 176d2cda0de introduced it as mandatory. Compatibility break. Commit 176d2cda0de is in v4.1.0. If I had learned about it a bit earlier, I would've argued for a last minute fix or a revert. Now we have a regression in the release. Eduardo, I think this fix should go into v4.1.1. Please add cc: qemu-stable. How can we best avoid such compatibility breaks to slip in undetected? A static checker would be nice. For vmstate, we have scripts/vmstate-static-checker.py. Not sure it's used.