From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756919AbXEQNXm (ORCPT ); Thu, 17 May 2007 09:23:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754797AbXEQNXf (ORCPT ); Thu, 17 May 2007 09:23:35 -0400 Received: from il.qumranet.com ([82.166.9.18]:53854 "EHLO il.qumranet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753981AbXEQNXe (ORCPT ); Thu, 17 May 2007 09:23:34 -0400 Message-ID: <464C574C.5020201@qumranet.com> Date: Thu, 17 May 2007 16:23:24 +0300 From: Avi Kivity User-Agent: Thunderbird 1.5.0.10 (X11/20070302) MIME-Version: 1.0 To: Jeremy Fitzhardinge CC: Andi Kleen , Andrew Morton , Linux Kernel Mailing List Subject: Re: 2.6.22-rc1-mm1: strange GPF when panicing under kvm References: <464B9E19.6050902@goop.org> In-Reply-To: <464B9E19.6050902@goop.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Jeremy Fitzhardinge wrote: > When I boot 2.6.22-rc1-mm1 under kvm, but forget to specify a root > filesystem, it panics as expected. However, when panicing, it gets a > GPF in delay_tsc, and then starts recursively panicing. > > I don't really understand what's going on; the instruction it's faulting > on seems to be "pause" (ie, rep;nop), which seems like it shouldn't > fault at all. It looks like some kvm artifact to me, but I'm not sure. > > Hm, given the error code, maybe it's a segment register problem. > > Strange. What does your msr 0x482 look like? If you have /dev/cpu/0/msr, the following will spit it out: ------------- #!/usr/bin/python import struct msrs = file('/dev/cpu/0/msr') msrs.seek(0x482) msr = msrs.read(8) msr = struct.unpack('Q', msr)[0] print '%x' % (msr,) ---------------- (that msr can force trapping of the pause instruction, even though there's no good reason to do it, and kvm wouldn't inject a gp if it did anyway). -- error compiling committee.c: too many arguments to function