From patchwork Mon Dec 12 20:49:05 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eduardo Habkost X-Patchwork-Id: 9471295 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 7E576607D3 for ; Mon, 12 Dec 2016 20:49:50 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7340B28518 for ; Mon, 12 Dec 2016 20:49:50 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 6509A2851B; Mon, 12 Dec 2016 20:49:50 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id C51AE28518 for ; Mon, 12 Dec 2016 20:49:49 +0000 (UTC) Received: from localhost ([::1]:33553 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cGXXg-0000gZ-5C for patchwork-qemu-devel@patchwork.kernel.org; Mon, 12 Dec 2016 15:49:48 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49265) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cGXXC-0000gH-Hq for qemu-devel@nongnu.org; Mon, 12 Dec 2016 15:49:20 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cGXX7-00046u-Ee for qemu-devel@nongnu.org; Mon, 12 Dec 2016 15:49:18 -0500 Received: from mx1.redhat.com ([209.132.183.28]:49930) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cGXX7-00046e-66; Mon, 12 Dec 2016 15:49:13 -0500 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 035844E4E5; Mon, 12 Dec 2016 20:49:12 +0000 (UTC) Received: from localhost (ovpn-116-2.gru2.redhat.com [10.97.116.2]) by int-mx11.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id uBCKnAqp012119; Mon, 12 Dec 2016 15:49:11 -0500 From: Eduardo Habkost To: qemu-devel@nongnu.org Date: Mon, 12 Dec 2016 18:49:05 -0200 Message-Id: <1481575745-26120-1-git-send-email-ehabkost@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.24 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Mon, 12 Dec 2016 20:49:12 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH for-2.8.1 v2] machine: Convert abstract typename on compat_props to subclass names X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Halil Pasic , "Michael S. Tsirkin" , Stefan Hajnoczi , qemu-stable@nongnu.org, Greg Kurz , Stefan Hajnoczi , Cornelia Huck , Paolo Bonzini Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP Original problem description by Greg Kurz: > Since commit "9a4c0e220d8a hw/virtio-pci: fix virtio > behaviour", passing -device virtio-blk-pci.disable-modern=off > has no effect on 2.6 machine types because the internal > virtio-pci.disable-modern=on compat property always prevail. The same bug also affects other abstract type names mentioned on compat_props by machine-types: apic-common, i386-cpu, pci-device, powerpc64-cpu, s390-skeys, spapr-pci-host-bridge, usb-device, virtio-pci, x86_64-cpu. The right fix for this problem is to make sure compat_props and -global options are always applied in the order they are registered, instead of reordering them based on the type hierarchy. But changing the ordering rules of -global is risky and might break existing configurations, so we shouldn't do that on a stable branch. This is a temporary hack that will work around the bug when registering compat_props properties: if we find an abstract class on compat_props, register properties for all its non-abstract subtypes instead. This will make sure -global won't be overridden by compat_props, while keeping the existing ordering rules on -global options. Note that there's one case that won't be fixed by this hack: "-global spapr-pci-vfio-host-bridge.