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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 9F5D1C433FF for ; Tue, 30 Jul 2019 10:26:28 +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 6F8062089E for ; Tue, 30 Jul 2019 10:26:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6F8062089E 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]:59474 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hsPKt-000110-Kk for qemu-devel@archiver.kernel.org; Tue, 30 Jul 2019 06:26:27 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:42331) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hsPK7-0000ZS-Sp for qemu-devel@nongnu.org; Tue, 30 Jul 2019 06:25:40 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hsPK6-00040N-Ua for qemu-devel@nongnu.org; Tue, 30 Jul 2019 06:25:39 -0400 Received: from mx1.redhat.com ([209.132.183.28]:53540) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hsPK6-0003yy-PS for qemu-devel@nongnu.org; Tue, 30 Jul 2019 06:25:38 -0400 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 58A5030860C8; Tue, 30 Jul 2019 10:25:37 +0000 (UTC) Received: from kinshicho (unknown [10.43.2.73]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 19692600CC; Tue, 30 Jul 2019 10:25:31 +0000 (UTC) Message-ID: From: Andrea Bolognani To: Sergio Lopez , mst@redhat.com Date: Tue, 30 Jul 2019 12:25:30 +0200 In-Reply-To: <20190729125755.45008-1-slp@redhat.com> References: <20190729125755.45008-1-slp@redhat.com> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.32.4 (3.32.4-1.fc30) MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.44]); Tue, 30 Jul 2019 10:25:37 +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] [RFC] virtio-mmio: implement modern (v2) personality (virtio-1) 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.maydell@linaro.org, qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Mon, 2019-07-29 at 14:57 +0200, Sergio Lopez wrote: [...] > /* virtio-mmio device */ > > static Property virtio_mmio_properties[] = { > DEFINE_PROP_BOOL("format_transport_address", VirtIOMMIOProxy, > format_transport_address, true), > + DEFINE_PROP_BOOL("modern", VirtIOMMIOProxy, modern, false), > DEFINE_PROP_END_OF_LIST(), > }; Not a QEMU developer so forgive me if I say something silly, but IIUC you'd be able to opt into the new feature by using eg. -device virtio-net-device,modern=on However, virtio-pci devices already have a mechanism to control the VirtIO protocol version, where you use -device virtio-net-pci,disable-modern=no,disable-legacy=yes to get a VirtIO 1.x-only device and -device virtio-net-pci,disable-modern=no,disable-legacy=no for a transitional device. Can you please make sure virtio-mmio uses the existing interface instead of introducing a new one? -- Andrea Bolognani / Red Hat / Virtualization