From mboxrd@z Thu Jan  1 00:00:00 1970
From: Sasha Levin <levinsasha928@gmail.com>
Subject: Re: [RFC] kvm tools: Add support for virtio-mmio
Date: Wed, 16 Nov 2011 15:30:21 +0200
Message-ID: <1321450221.3221.13.camel@lappy>
References: <1321375667-17284-1-git-send-email-levinsasha928@gmail.com>
	 <CAFEAcA-2QGk_Y1R_FPrVRVGiP7KyQOuv0zubORm77cOoU_K6gQ@mail.gmail.com>
	 <1321379773.3200.9.camel@lappy>
	 <1321449718.3137.258.camel@hornet.cambridge.arm.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=iso-8859-2
Content-Transfer-Encoding: QUOTED-PRINTABLE
Cc: Peter Maydell <peter.maydell@linaro.org>,
	"penberg@kernel.org" <penberg@kernel.org>,
	"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
	"mingo@elte.hu" <mingo@elte.hu>,
	"asias.hejun@gmail.com" <asias.hejun@gmail.com>,
	"gorcunov@gmail.com" <gorcunov@gmail.com>,
	Rusty Russell <rusty@rustcorp.com.au>,
	"virtualization@lists.linux-foundation.org"
	<virtualization@lists.linux-foundation.org>
To: Pawel Moll <pawel.moll@arm.com>
Return-path: <kvm-owner@vger.kernel.org>
Received: from mail-ww0-f44.google.com ([74.125.82.44]:58021 "EHLO
	mail-ww0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1756655Ab1KPNcZ (ORCPT <rfc822;kvm@vger.kernel.org>);
	Wed, 16 Nov 2011 08:32:25 -0500
Received: by wwe5 with SMTP id 5so732611wwe.1
        for <kvm@vger.kernel.org>; Wed, 16 Nov 2011 05:32:23 -0800 (PST)
In-Reply-To: <1321449718.3137.258.camel@hornet.cambridge.arm.com>
Sender: kvm-owner@vger.kernel.org
List-ID: <kvm.vger.kernel.org>

On Wed, 2011-11-16 at 13:21 +0000, Pawel Moll wrote:
> On Tue, 2011-11-15 at 17:56 +0000, Sasha Levin wrote:
> > Hmm... If thats the plan, it should probably be a virtio thing (not
> > virtio-mmio specific).
> >=20
> > Either way, it could also use some clarification in the spec.
>=20
> Well, the spec (p. 2.1) says: "The Subsystem Vendor ID should reflect
> the PCI Vendor ID of the environment (it's currently only used for
> informational purposes by the guest).". The fact is that all the curr=
ent
> virtio drivers simply ignore this field. So unless this changes I sim=
ply
> have no idea how to describe that register. "Put anything there, no o=
ne
> cares"? "Write zero now, may change in future"? Any ideas welcomed.
>=20
> Cheers!
>=20
> Pawe=B3
>=20
> PS. Thanks for defending my honour in the delayed-explosive-device
> thread ;-)

We can add an appendix to the virtio spec with known virtio subsystem
vendors, patch QEMU & KVM tool to pass that, and possibly modify the
QEMU related workarounds in the kernel to only do the workaround thing
if QEMU is set as the vendor.

--=20

Sasha.