From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43)
	id 1Mvxuj-0007VI-Sa
	for qemu-devel@nongnu.org; Thu, 08 Oct 2009 14:40:33 -0400
Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43)
	id 1Mvxue-0007PO-V5
	for qemu-devel@nongnu.org; Thu, 08 Oct 2009 14:40:33 -0400
Received: from [199.232.76.173] (port=52766 helo=monty-python.gnu.org)
	by lists.gnu.org with esmtp (Exim 4.43) id 1Mvxue-0007P6-Qk
	for qemu-devel@nongnu.org; Thu, 08 Oct 2009 14:40:28 -0400
Received: from mail2.shareable.org ([80.68.89.115]:50896)
	by monty-python.gnu.org with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA1:32)
	(Exim 4.60) (envelope-from <jamie@shareable.org>) id 1Mvxue-0002a0-DF
	for qemu-devel@nongnu.org; Thu, 08 Oct 2009 14:40:28 -0400
Date: Thu, 8 Oct 2009 19:40:12 +0100
From: Jamie Lokier <jamie@shareable.org>
Subject: Re: [Qemu-devel] Re: [PATCH 2/3] qemu: make cirrus init value pci
	spec compliant
Message-ID: <20091008184011.GA6576@shareable.org>
References: <cover.1255013225.git.mst@redhat.com>
	<20091008145241.GC12275@redhat.com> <4ACE0559.5040206@redhat.com>
	<20091008160623.GA13710@redhat.com> <4ACE0FC6.3050908@redhat.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <4ACE0FC6.3050908@redhat.com>
List-Id: qemu-devel.nongnu.org
List-Unsubscribe: <http://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.gnu.org/pipermail/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <http://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Avi Kivity <avi@redhat.com>
Cc: Anthony Liguori <aliguori@us.ibm.com>, "qemu-devel@nongnu.org" <qemu-devel@nongnu.org>, kvm-devel <kvm@vger.kernel.org>, "Michael S. Tsirkin" <mst@redhat.com>

Avi Kivity wrote:
> On 10/08/2009 06:06 PM, Michael S. Tsirkin wrote:
> >On Thu, Oct 08, 2009 at 05:29:29PM +0200, Avi Kivity wrote:
> >   
> >>On 10/08/2009 04:52 PM, Michael S. Tsirkin wrote:
> >>     
> >>>PCI memory should be disabled at reset, otherwise
> >>>we might claim transactions at address 0.
> >>>I/O should also be disabled, although for cirrus
> >>>it is harmless to enable it as we do not
> >>>have I/O bar.
> >>>
> >>>Note: need bios fix for this patch to work:
> >>>currently pc-bios incorrently assumes that it does not
> >>>need to enable i/o unless device has i/o bar.
> >>>
> >>>Signed-off-by: Michael S. Tsirkin<mst@redhat.com>
> >>
> >>This needs to be conditional on the machine type.  Old machines must
> >>retain this code for live migration to work (we need to live migrate the
> >>bios, so we can't assume the bios fix is in during live migration from
> >>older qemus).
> >>     
> >No, if you migrate from older qemu you will be fine as command
> >is enabled there on init.
> >   
> 
> Right.

No, I think Avi was right the first time.

Migrating from an older qemu will be fine at first, but at the next
reset _following_ migration, it'll be running the old BIOS on a new
qemu and fail.

-- Jamie