From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1M9cAD-0008DZ-PA for qemu-devel@nongnu.org; Thu, 28 May 2009 05:44:41 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1M9cAA-00088k-9M for qemu-devel@nongnu.org; Thu, 28 May 2009 05:44:41 -0400 Received: from [199.232.76.173] (port=37664 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1M9cA9-00088G-CI for qemu-devel@nongnu.org; Thu, 28 May 2009 05:44:37 -0400 Received: from e31.co.us.ibm.com ([32.97.110.149]:36617) by monty-python.gnu.org with esmtps (TLS-1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1M9cA8-0006uo-SU for qemu-devel@nongnu.org; Thu, 28 May 2009 05:44:37 -0400 Received: from d03relay02.boulder.ibm.com (d03relay02.boulder.ibm.com [9.17.195.227]) by e31.co.us.ibm.com (8.13.1/8.13.1) with ESMTP id n4S9eWAi006381 for ; Thu, 28 May 2009 03:40:32 -0600 Received: from d03av01.boulder.ibm.com (d03av01.boulder.ibm.com [9.17.195.167]) by d03relay02.boulder.ibm.com (8.13.8/8.13.8/NCO v9.2) with ESMTP id n4S9iZmH228180 for ; Thu, 28 May 2009 03:44:35 -0600 Received: from d03av01.boulder.ibm.com (loopback [127.0.0.1]) by d03av01.boulder.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id n4S9iZlV003783 for ; Thu, 28 May 2009 03:44:35 -0600 Message-ID: <4A1E5D01.6000005@us.ibm.com> Date: Thu, 28 May 2009 04:44:33 -0500 From: Anthony Liguori MIME-Version: 1.0 Subject: Re: [Qemu-devel] [PATCH] Change virtio-console to PCI_CLASS_SERIAL_OTHER References: <1243012478.29542.18.camel@blaa> <4A1D4C57.6010109@us.ibm.com> <1243446153.4852.9.camel@blaa> <4A1DC0C0.2060200@us.ibm.com> <1243503206.4046.56.camel@blaa> In-Reply-To: <1243503206.4046.56.camel@blaa> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Mark McLoughlin Cc: Dor Laor , ajax@redhat.com, qemu-devel Mark McLoughlin wrote: > On Wed, 2009-05-27 at 17:37 -0500, Anthony Liguori wrote: > >> This is can't really be a hard rule yet without the machine config, but >> we should do our best when we can. >> > > There's not much point in doing this unless there's some practical way > to use it. > > If we e.g. add a 'class' parameter for virtio-blk and virtio-console, > we'd also need to add some way for a management tool to figure out what > the class value is when it initially creates the guest and, for ever > more, supply that value. > > Options I see: > > 1) Add a monitor command to query the class values and delay actually > changing the values until the next release cycle > > 2) Use 'info version' to achieve this - management tools would need to > start retaining the version that guests were created with and > supplying that version to qemu on the command line. As you say, > though, linear versioning sucks > > 3) Decide we can only make these guarantees with the machine config > stuff - management tools would need to query a running qemu for a > detailed machine config when initially creating the guest and > always supply that when later starting the guest > Today, the qdev stuff supports properties for devices. If you make class a property of these devices, you would just need something to dump the device properties for a given device. I think it should be a relatively straight forward thing today. Regards, Anthony Liguori > Cheers, > Mark. > >