From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: KVM guest crashes Date: Tue, 20 Jan 2009 22:07:47 +0200 Message-ID: <49762F13.5040507@redhat.com> References: <4975F26D.707@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: "kvm@vger.kernel.org" , Marcelo Tosatti , Joerg Roedel , Sheng Yang To: Alexander Graf Return-path: Received: from mx2.redhat.com ([66.187.237.31]:41516 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758590AbZATUIK (ORCPT ); Tue, 20 Jan 2009 15:08:10 -0500 In-Reply-To: <4975F26D.707@suse.de> Sender: kvm-owner@vger.kernel.org List-ID: Alexander Graf wrote: > Hi list, > > recently I've been hitting some KVM bugs others seem to have reported as > well, including > > - CIFS timeouts > - Stuck ?? errors > - Random segmentation faults in the guest > > so I figured, I'll put together a stress test that can be used to > reproduce these issues. This is done by using a CIFS mount on the host > and unpacking data from that mount to the mount. I have been able to > bring kvm down to its knees a lot just by doing this. > Simply run the test in an endless-loop. FWIW enabling NPT helps > triggering the issue. > > Are the problems specific to AMD? What does "helps triggering" mean - does it happen with NPT disabled? > The guest kernels included here are openSUSE 11.0 (2.6.25) and 11.1 > (2.6.27) kernels. > > Find the tests here: http://alex.csgraf.de/kvm-tests.tar.bz2 > And some logs here (NPT enabled): http://alex.csgraf.de/kvm-logs.tar.bz2 > > I'm somewhat lost on the reason for these failures, so if you do have > some time on your hands, please give me a hand debugging this! If I'd > had to guess, I'd say it's either an APIC issue and/or guest memory > corruption. > I'd guess memory corruption. Does running a uniprocessor guest help? What about a uniprocessor guest pinned to one host core? -- Do not meddle in the internals of kernels, for they are subtle and quick to panic.