From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Thomason Subject: Re: BUG: Guest lockup and 100% CPU load on host Date: Thu, 15 Jan 2009 15:00:08 -0800 Message-ID: References: <496FB451.3020002@t-online.de> Mime-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit To: "Jan C. Bernauer" , Return-path: Received: from multiply.divide.org ([207.218.248.89]:58292 "EHLO multiply.divide.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S936125AbZAOXAU (ORCPT ); Thu, 15 Jan 2009 18:00:20 -0500 In-Reply-To: <496FB451.3020002@t-online.de> Sender: kvm-owner@vger.kernel.org List-ID: Jan, I spent some time with the same problem over the last two days. Avi Kivity suggested adding "clocksource=acpi_pm" to the guest kernel boot line, and that seems to have resolved the issue. Would you give that a try and let me know the result? Also I believe the following bugs might be related: [ 2351676 ] Guests hang periodically on Ubuntu-8.10 [ 2353811 ] Solaris 10 guest unstable [ 2494730 ] Guests "stalling" on kvm-82 [ 2138079 ] kvm locks up system [ 2113643 ] guests AND host still getting stuck under CPU load Regards, James On 1/15/09 2:10 PM, "Jan C. Bernauer" wrote: > Hi, > > while I was trying to get pci passthrough to work without vt-d using > the 1to1 mapping (it works ;), > I stumbled upon a solid lock up of the guest. > (Unpatched source shows the same behaviour) > > I see a strange look up of the guest OS with the following "features": > - guest doesn't respond anymore > - triggered by load in the guest. > - it seems it is easier to trigger with -smp 2 > - host shows qemu process with 100% cpu > - seems to be cured by --no-kvm-irqchip > - --no-kvm-pit does not help > - qmeu console command system_reset works > > Right now, guest OS is linux 2.6.27.1 > Latest KVM from git, host is 2.6.28. > Older kvms seem to exhibit the same problem.