Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752303AbbG3PF7 (ORCPT ); Thu, 30 Jul 2015 11:05:59 -0400 Received: from mx1.redhat.com ([209.132.183.28]:42732 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750847AbbG3PF6 (ORCPT ); Thu, 30 Jul 2015 11:05:58 -0400 Date: Thu, 30 Jul 2015 18:05:52 +0300 From: "Michael S. Tsirkin" To: Peter Maydell Cc: Shannon Zhao , QEMU Developers , Graeme Gregory , lkml - Kernel Mailing List , "virtualization@lists.linux-foundation.org" , Shannon Zhao , Igor Mammedov , Alex =?iso-8859-1?Q?Benn=E9e?= Subject: Re: [Qemu-devel] [PATCH v2] arm: change vendor ID for virtio-mmio Message-ID: <20150730180303-mutt-send-email-mst@redhat.com> References: <1438196676-30255-1-git-send-email-mst@redhat.com> <55B97C88.6010004@linaro.org> <20150730105923-mutt-send-email-mst@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1901 Lines: 47 On Thu, Jul 30, 2015 at 10:24:11AM +0100, Peter Maydell wrote: > On 30 July 2015 at 09:04, Michael S. Tsirkin wrote: > > On Thu, Jul 30, 2015 at 09:23:20AM +0800, Shannon Zhao wrote: > >> > >> Why do we drop the previous way using "QEMUXXXX"? Something I missed? > > > > So that guests that bind to this interface will work fine with non QEMU > > implementations of virtio-mmio. > > I don't understand this sentence. If there are pre-existing > non-QEMU virtio-mmio implementations, then they're using > LNRO0005, and we should use it too. If there are going to > be implementations of virtio-mmio in future, then they will > use whatever identifier we pick here. Either way, we get > interoperability. I don't see any difference between our > saying "the ID for virtio-mmio is QEMU0005" and saying > "the ID for virtio-mmio is 1AF4103F". I agree. It's just that 1AF4 is already reserved for virtio. > (The latter seems unnecessarily opaque to me, to be honest. > At least an ID string QEMUxxxx gives you a clue where to > look for who owns the thing.) Well - if one looks in the ACPI spec, that says if ID uses numbers, then one has to find the vendor from PCI SIG, and that has a database mapping IDs to vendors. > > Note also that strictly you don't mean "non-QEMU implementations > of virtio-mmio", you mean "non-QEMU implementations of the > ACPI tables". Yes. > The hardware implementation of virtio-mmio > doesn't care at all about the ACPI ID. (In fact the most > plausible other-implementation would be UEFI using its > own (hard-coded) ACPI tables on top of a QEMU vexpress-a15 > model or something similar.) > > -- PMM -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/