From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1NMNBd-0006LB-Bp for qemu-devel@nongnu.org; Sun, 20 Dec 2009 09:55:09 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1NMNBY-0006Jl-QT for qemu-devel@nongnu.org; Sun, 20 Dec 2009 09:55:08 -0500 Received: from [199.232.76.173] (port=44783 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NMNBY-0006Je-Hy for qemu-devel@nongnu.org; Sun, 20 Dec 2009 09:55:04 -0500 Received: from mx1.redhat.com ([209.132.183.28]:13624) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1NMNBY-0007Kz-2X for qemu-devel@nongnu.org; Sun, 20 Dec 2009 09:55:04 -0500 Message-ID: <4B2E3AC5.3040200@redhat.com> Date: Sun, 20 Dec 2009 16:55:01 +0200 From: Avi Kivity MIME-Version: 1.0 Subject: Re: [Qemu-devel] cpuid problem in upstream qemu with kvm References: <20091214193541.GA6150@redhat.com> <4B269596.1050103@codemonkey.ws> <20091214194432.GC6150@redhat.com> <4B2698A9.9090107@codemonkey.ws> <20091214200002.GA27769@redhat.com> <4B2699BB.1090302@codemonkey.ws> <20091214201049.GD6150@redhat.com> <4B269D99.8080404@codemonkey.ws> <4B2DF334.6030208@redhat.com> <4B2E3943.9020802@codemonkey.ws> In-Reply-To: <4B2E3943.9020802@codemonkey.ws> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Anthony Liguori Cc: qemu-devel@nongnu.org, Gleb Natapov , "Michael S. Tsirkin" On 12/20/2009 04:48 PM, Anthony Liguori wrote: > Avi Kivity wrote: >> >> Maybe we should make -cpu host the default. That will give the best >> performance for casual users, more testing for newer features, and >> will force management apps to treat migration much more seriously. >> The downside is that casual users upgrading their machines might >> experience issues with Windows. Feature compatibility is not just >> about migration. > > Yes, I'd much rather do this than mucking with vendor_id. If we're > going to give up on cross vendor migration by default, I think we > should go for best performance. If we do this, we need to advertise it clearly: - casual (non-management-app-using) users will start seeing problems with Windows guests unless they change their command lines - management apps really have to take cpuid into account now (previously, it was just a good idea) -- error compiling committee.c: too many arguments to function