From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1NMge1-0003jo-1b for qemu-devel@nongnu.org; Mon, 21 Dec 2009 06:41:45 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1NMgdw-0003in-LP for qemu-devel@nongnu.org; Mon, 21 Dec 2009 06:41:44 -0500 Received: from [199.232.76.173] (port=52863 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NMgdw-0003ik-Dj for qemu-devel@nongnu.org; Mon, 21 Dec 2009 06:41:40 -0500 Received: from mx1.redhat.com ([209.132.183.28]:18670) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1NMgdv-0007z3-VR for qemu-devel@nongnu.org; Mon, 21 Dec 2009 06:41:40 -0500 Date: Mon, 21 Dec 2009 13:38:53 +0200 From: "Michael S. Tsirkin" Subject: Re: [Qemu-devel] cpuid problem in upstream qemu with kvm Message-ID: <20091221113852.GB6309@redhat.com> References: <4B269D99.8080404@codemonkey.ws> <4B2DF334.6030208@redhat.com> <20091220155101.GB31257@redhat.com> <4B2E49E5.6050709@redhat.com> <20091220165612.GC31257@redhat.com> <20091220171822.GD31257@redhat.com> <4B2F581A.7030206@redhat.com> <20091221111856.GA6309@redhat.com> <0B948C77-7A15-4321-BA7C-059AA5FC3019@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <0B948C77-7A15-4321-BA7C-059AA5FC3019@suse.de> List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexander Graf Cc: Avi Kivity , Gleb Natapov , qemu-devel@nongnu.org On Mon, Dec 21, 2009 at 12:22:53PM +0100, Alexander Graf wrote: > > On 21.12.2009, at 12:18, Michael S. Tsirkin wrote: > > > On Mon, Dec 21, 2009 at 01:12:26PM +0200, Avi Kivity wrote: > >> On 12/20/2009 07:18 PM, Michael S. Tsirkin wrote: > >>> > >>>>> Hmm, then, shouldn't either kvm or qemu mask features that we do not > >>>>> emulate well enough to make windows not crash? > >>>>> > >>>> -cpu host does that already, no? > >>>> > >>>> Alex > >>>> > >>> I expected so, but Avi here seems to say windows will crash if you > >>> use a new CPU with it ... > >>> > >> > >> No, Windows tries to detect changes in your hardware and assumes that if > >> too many things change, you might be a pirate and requires you to phone > >> their offices to re-authenticate. > > > > How often does a casual user upgrade his host CPU? > > I tend to have my VM images on an NFS share and expect them to work properly on all PCs I work on. > So I guess the answer is "often"? > > Alex Yes but you are not a casual user, are you? Consider a 64 bit guest to see why moving a VM across machines needs some planning. -- MST