From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43)
	id 1MNogp-0005FD-Fk
	for qemu-devel@nongnu.org; Mon, 06 Jul 2009 09:57:03 -0400
Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43)
	id 1MNogk-0005DT-4R
	for qemu-devel@nongnu.org; Mon, 06 Jul 2009 09:57:02 -0400
Received: from [199.232.76.173] (port=40367 helo=monty-python.gnu.org)
	by lists.gnu.org with esmtp (Exim 4.43) id 1MNogj-0005DJ-T5
	for qemu-devel@nongnu.org; Mon, 06 Jul 2009 09:56:57 -0400
Received: from mx2.redhat.com ([66.187.237.31]:46216)
	by monty-python.gnu.org with esmtp (Exim 4.60)
	(envelope-from <mst@redhat.com>) id 1MNogj-0001iC-9w
	for qemu-devel@nongnu.org; Mon, 06 Jul 2009 09:56:57 -0400
Date: Mon, 6 Jul 2009 16:56:16 +0300
From: "Michael S. Tsirkin" <mst@redhat.com>
Subject: Re: [Qemu-devel] Re: [PATCH 0/4] Machine config files
Message-ID: <20090706135616.GA12141@redhat.com>
References: <20090610173803.4674.82538.stgit@wren.home>
	<878wjx374h.fsf@pike.pond.sub.org>
	<4A3269C3.3050307@redhat.com> <4A327E2C.1060207@siemens.com>
	<20090706124928.GB11998@redhat.com> <4A51FF7B.4000602@redhat.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <4A51FF7B.4000602@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: Gerd Hoffmann <kraxel@redhat.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>, Markus Armbruster <armbru@redhat.com>, qemu-devel@nongnu.org

On Mon, Jul 06, 2009 at 03:43:23PM +0200, Gerd Hoffmann wrote:
> On 07/06/09 14:49, Michael S. Tsirkin wrote:
>> On Fri, Jun 12, 2009 at 06:11:24PM +0200, Jan Kiszka wrote:
>> Can't we extend loadvm/savevm format to support machine config? It is
>> already supported by all devices, it seems that we just need to add some
>> detail such as pci addresses, and qemu flags to save/load this config.
>> No?
>
> No.  Adding some info to the devices doesn't cut it as you also need to  
> know which devices are present in the first place.

Actually at least for pci devices you have the devid/vendor id
register - from this you can know which devices are present.

>  Current savevm  
> doesn't do that, thats why you have to start the virtual machine with  
> the complete set of command line arguments even when resuming /  
> migrating.  Once we have a working device tree implementation we can fix  
> that too though.  Rough plan is:
>
>   (1) convert drivers to qdev.
>   (2) create qdev device tree from config file (probably fdt).
>
> With this in place it is just a little step to also carry this in the  
> savevm format:  We just need a to do a qdev->fdt conversion, then we can  
> send the device tree as one savevm section and rebuild the vm from that.
>
> cheers,
>   Gerd