From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anthony Liguori Subject: Re: Linux in VirtualPC in KVM fails Date: Fri, 09 Jan 2009 14:10:57 -0600 Message-ID: <4967AF51.6060400@codemonkey.ws> References: <4967708E.2060907@suse.de> <49678E6E.4020306@redhat.com> <49679FAA.3000802@codemonkey.ws> <4967A64C.7070702@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Alexander Graf , Kevin Wolf , kvm@vger.kernel.org To: Avi Kivity Return-path: Received: from mail-ew0-f17.google.com ([209.85.219.17]:51583 "EHLO mail-ew0-f17.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753028AbZAIULZ (ORCPT ); Fri, 9 Jan 2009 15:11:25 -0500 Received: by ewy10 with SMTP id 10so10421019ewy.13 for ; Fri, 09 Jan 2009 12:11:24 -0800 (PST) In-Reply-To: <4967A64C.7070702@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: Avi Kivity wrote: > Anthony Liguori wrote: >> Alexander Graf wrote: >>> >>> Shouldn't it be ok to push patches to linux-stable to use the CPUID >>> and MSR information and simply not expose the CPUID identification >>> in newer KVM versions? That way older guests on newer KVM don't use >>> KVM paravirt (which should still be ok), but everything else runs as >>> smoothly as possible. >> >> I'd say that VirtualPC is broken and leave it at that. >> >> All modern hypervisors use CPUID to expose themselves to the guests. >> VirtualPC is totally capable of rewriting CPUID instructions. > > Apparently it isn't. I know of one other fullvirt product that does > not jit kernel code. Or maybe they wanted to preserve consistency > between kernel cpuid and host cpuid. How can you get away with not jitting kernel code? Regards, Anthony Liguori