From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758588AbXFLGoX (ORCPT ); Tue, 12 Jun 2007 02:44:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756505AbXFLGoR (ORCPT ); Tue, 12 Jun 2007 02:44:17 -0400 Received: from il.qumranet.com ([82.166.9.18]:56972 "EHLO il.qumranet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752956AbXFLGoQ (ORCPT ); Tue, 12 Jun 2007 02:44:16 -0400 Message-ID: <466E40BD.8080001@qumranet.com> Date: Tue, 12 Jun 2007 09:44:13 +0300 From: Avi Kivity User-Agent: Thunderbird 2.0.0.0 (X11/20070419) MIME-Version: 1.0 To: Luca CC: kvm-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org Subject: Re: [kvm-devel] [BUG] Oops with KVM-27 References: <20070603213432.GA3075@dreamland.darkstar.lan> <4663DCE9.3000107@qumranet.com> <20070604202248.GA18668@dreamland.darkstar.lan> <46647B3E.2090205@qumranet.com> <20070604212207.GA22365@dreamland.darkstar.lan> <46651069.5040003@qumranet.com> <68676e00706071216i4bd051c5hb1c114f3c13ab97f@mail.gmail.com> <466BED18.5040708@qumranet.com> <68676e00706101354n5fe7e1a9y12cb690cae2924e3@mail.gmail.com> <466CFD6D.2080201@qumranet.com> <68676e00706111406r16eafd0eseaf1fb24f5c0d075@mail.gmail.com> In-Reply-To: <68676e00706111406r16eafd0eseaf1fb24f5c0d075@mail.gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-3.0 (firebolt.argo.co.il [0.0.0.0]); Tue, 12 Jun 2007 09:44:13 +0300 (IDT) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Luca wrote: > On 6/11/07, Avi Kivity wrote: >> Luca wrote: >> >> >> >> I've managed to reproduce this on kvm-21 (it takes many boots for >> this >> >> to happen, but it does eventually). >> > >> > Hum, any clue on the cause? >> >> From what I've seen, it's the new Linux clocksource code. > > Actually I tried forcing the PIT (and any other combination of > tsc,acpi_pm,jiffies) as the clocksource, without success. > Well, there's lots of APIC stuff going on when it hangs. >> > Should I test older versions? >> >> They're unlikely to be better. Instead, it would be best to see what >> the guest is doing. >> >> I suggest downloading the source rpm for the kernel, building it, and >> sprinkling printk()s until we know exactly what source the guest is >> executing at the time of the hang. > > Ok, will do. Meanwhile I discovered that the kernel on the boot cd > (the one that hangs) is compiled for i586, while the one installed on > disk is for i686 (this one works). Ah. > > i686 has this options enabled: > > +CONFIG_X86_GOOD_APIC=y > +CONFIG_X86_USE_PPRO_CHECKSUM=y > +CONFIG_X86_TSC=y > > but disabling tsc on the command line doesn't make any difference. Is > it possible that KVM is choking on some instruction not used by the > i686 kernel? Unlikely, as then the hang would occur all the time instead of randomly. -- Do not meddle in the internals of kernels, for they are subtle and quick to panic.