From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([2001:4830:134:3::10]:44887)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <armbru@redhat.com>) id 1XK6xK-0003ls-8z
	for qemu-devel@nongnu.org; Wed, 20 Aug 2014 10:33:48 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <armbru@redhat.com>) id 1XK6xE-0005ZP-4c
	for qemu-devel@nongnu.org; Wed, 20 Aug 2014 10:33:42 -0400
Received: from mx1.redhat.com ([209.132.183.28]:48110)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <armbru@redhat.com>) id 1XK6xD-0005ZJ-U9
	for qemu-devel@nongnu.org; Wed, 20 Aug 2014 10:33:36 -0400
From: Markus Armbruster <armbru@redhat.com>
References: <1408517593.25437.102.camel@ori.omang.mine.nu>
	<53F461E6.5020506@redhat.com>
	<1408527055.14053.107.camel@abi.no.oracle.com>
	<87k3631i29.fsf@blackfin.pond.sub.org>
	<20140820123357.GA18304@redhat.com>
	<87ppfvxqgw.fsf@blackfin.pond.sub.org> <53F4A03F.9050300@redhat.com>
Date: Wed, 20 Aug 2014 16:28:13 +0200
In-Reply-To: <53F4A03F.9050300@redhat.com> (Paolo Bonzini's message of "Wed,
	20 Aug 2014 15:18:55 +0200")
Message-ID: <87r40bw802.fsf@blackfin.pond.sub.org>
MIME-Version: 1.0
Content-Type: text/plain
Subject: Re: [Qemu-devel] [PATCH 2/3] ioh3420: Provide a unique bus name and
	an interrupt mapping function
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Marcel Apfelbaum <marcel.a@redhat.com>, Alexey Kardashevskiy <aik@ozlabs.ru>, Juan Quintela <quintela@redhat.com>, Knut Omang <knut.omang@oracle.com>, qemu-devel@nongnu.org, Gonglei <arei.gonglei@huawei.com>, "Michael S. Tsirkin" <mst@redhat.com>, Igor Mammedov <imammedo@redhat.com>

Paolo Bonzini <pbonzini@redhat.com> writes:

> Il 20/08/2014 15:03, Markus Armbruster ha scritto:
>>> >
>>> > This is for the root bus, I think it won't help Knut who's trying to
>>> > add devices behind root ports.
>> Read again, more slowly :)
>> 
>> Yes, I null the name of the root bus.  That makes the qdev machinery
>> derive the very same "pcie.0" name via rule 3 instead of rule 1, with
>> the side effect that future (non-root) PCIE buses get different names.
>> In particular, the next one named via rule 3 will be called "pcie.1"
>> instead of "pcie.0", making it actually accessible.
>
> I agree that this is a big improvement.

It's also an ABI break.  I'm not saying we can't do it, just that we
better consider it carefully.