From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1L17WQ-00064b-U1 for qemu-devel@nongnu.org; Fri, 14 Nov 2008 17:52:14 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1L17WP-00064P-2d for qemu-devel@nongnu.org; Fri, 14 Nov 2008 17:52:14 -0500 Received: from [199.232.76.173] (port=55960 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1L17WO-00064M-SC for qemu-devel@nongnu.org; Fri, 14 Nov 2008 17:52:12 -0500 Received: from mail2.shareable.org ([80.68.89.115]:60837) by monty-python.gnu.org with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1L17WO-0003R3-Lu for qemu-devel@nongnu.org; Fri, 14 Nov 2008 17:52:12 -0500 Date: Fri, 14 Nov 2008 22:52:09 +0000 From: Jamie Lokier Subject: Re: [Qemu-devel] Re: [PATCH 0/5] Add "info capabilities" monitor command Message-ID: <20081114225209.GB19384@shareable.org> References: <1226594763-2304-1-git-send-email-markmc@redhat.com> <491CF04F.5020408@codemonkey.ws> <1226677902.9332.87.camel@blaa> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1226677902.9332.87.camel@blaa> Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Mark McLoughlin , qemu-devel@nongnu.org Mark McLoughlin wrote: > e.g. the drive cache options are example of features which aren't > visible to the guest, but if you go to migrate a guest using > cache=writethrough and discover the target host doesn't support that, > then presumably you don't proceed. I disagree, and think that's a perfectly reasonable migration. Of course you might want to know in advance that the target host doesn't support this option, so you can decide what to do. I'd go a bit further - it would be good to be able to change cache=? and all other values which are invisible to the guest _without_ having to do a migration too. > Which is similar to not migrating a > virtio using guest to a host without virtio support. No, that's migrating to a host which doesn't support a particular device. Same if, say, the guest is using e1000 and the target host doesn't have e1000 support. -- JAmie