From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1MxL9b-0002H3-RD for qemu-devel@nongnu.org; Mon, 12 Oct 2009 09:41:35 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1MxL9X-0002E5-8s for qemu-devel@nongnu.org; Mon, 12 Oct 2009 09:41:35 -0400 Received: from [199.232.76.173] (port=52699 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1MxL9W-0002Dx-Vv for qemu-devel@nongnu.org; Mon, 12 Oct 2009 09:41:31 -0400 Received: from e37.co.us.ibm.com ([32.97.110.158]:46330) by monty-python.gnu.org with esmtps (TLS-1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1MxL9W-0007TM-9s for qemu-devel@nongnu.org; Mon, 12 Oct 2009 09:41:30 -0400 Received: from d03relay04.boulder.ibm.com (d03relay04.boulder.ibm.com [9.17.195.106]) by e37.co.us.ibm.com (8.14.3/8.13.1) with ESMTP id n9CDeMl4003344 for ; Mon, 12 Oct 2009 07:40:22 -0600 Received: from d03av03.boulder.ibm.com (d03av03.boulder.ibm.com [9.17.195.169]) by d03relay04.boulder.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id n9CDfLV8118516 for ; Mon, 12 Oct 2009 07:41:21 -0600 Received: from d03av03.boulder.ibm.com (loopback [127.0.0.1]) by d03av03.boulder.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id n9CDfLBe025567 for ; Mon, 12 Oct 2009 07:41:21 -0600 Message-ID: <4AD33200.5060007@us.ibm.com> Date: Mon, 12 Oct 2009 08:41:20 -0500 From: Anthony Liguori MIME-Version: 1.0 Subject: Re: [Qemu-devel] Re: [PATCH v2 4/9] provide in-kernel apic References: <1254953315-5761-1-git-send-email-glommer@redhat.com> <1254953315-5761-2-git-send-email-glommer@redhat.com> <1254953315-5761-3-git-send-email-glommer@redhat.com> <1254953315-5761-4-git-send-email-glommer@redhat.com> <1254953315-5761-5-git-send-email-glommer@redhat.com> <4ACDEF42.6020706@us.ibm.com> <4ACDF297.9010303@redhat.com> <20091008142202.GR8092@mothafucka.localdomain> <20091009100641.GC6576@shareable.org> <20091009143031.GU8092@mothafucka.localdomain> <20091009164831.GB7393@shareable.org> <4ACF93D5.3010002@us.ibm.com> <4AD1A112.4070303@redhat.com> In-Reply-To: <4AD1A112.4070303@redhat.com> 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: Avi Kivity Cc: Glauber Costa , qemu-devel@nongnu.org, kvm-devel Avi Kivity wrote: > On 10/09/2009 09:49 PM, Anthony Liguori wrote: >>> If I've just been sent an image produced by someone running KVM, and >>> my machine is not KVM-capable, or I cannot upgrade the KVM kernel >>> module because it's in use by other VMs (had this problem a few >>> times), there's no choice but to change the irqchipness. >> >> >> You cannot migrate from KVM to TCG so this use-case is irrelevant. > > I agree it's mostly irrelevant, however nothing in principle prevents > such a migration, as long as the cpuid feature bits are implemented on > both sides. Sure, in principle it's certainly possible but in practice, it isn't today and I don't see anything that's likely to happen in the near term future that would make it. -- Regards, Anthony Liguori