From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: kvm causing memory corruption? now 2.6.26-rc4 Date: Thu, 12 Jun 2008 16:10:00 +0300 Message-ID: <48512028.3070104@qumranet.com> References: <1206479576.7562.21.camel@nimitz.home.sr71.net> <47EA1C63.8010202@qumranet.com> <1206550329.7883.5.camel@nimitz.home.sr71.net> <47EA80AC.4070204@qumranet.com> <1206551794.7883.7.camel@nimitz.home.sr71.net> <47EB6AAC.3040607@qumranet.com> <47EB7281.6070300@qumranet.com> <1206629709.7883.30.camel@nimitz.home.sr71.net> <47EBB63E.2060306@qumranet.com> <1212445810.8211.9.camel@nimitz.home.sr71.net> <48469BDA.3050206@qumranet.com> <1212738105.7837.3.camel@nimitz> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: "linux-kernel@vger.kernel.org" , kvm-devel , "Anthony N. Liguori [imap]" To: Dave Hansen Return-path: Received: from il.qumranet.com ([212.179.150.194]:48173 "EHLO il.qumranet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761126AbYFLNML (ORCPT ); Thu, 12 Jun 2008 09:12:11 -0400 In-Reply-To: <1212738105.7837.3.camel@nimitz> Sender: kvm-owner@vger.kernel.org List-ID: Dave Hansen wrote: > On Wed, 2008-06-04 at 16:42 +0300, Avi Kivity wrote: > >> Dave Hansen wrote: >> > ... > >>> After collecting all those, I turned on CONFIG_DEBUG_HIGHMEM and the >>> oopses miraculously stopped. But, the guest hung (for at least 5 >>> minutes or so) during windows bootup, pegging my host CPU. Most of the >>> CPU was going to klogd, so I checked dmesg. >>> >>> >> Can you check with mem=900 (and CONFIG_HIGHMEM_DEBUG=n)? That will >> confirm that the problems are highmem related, but not physical address >> truncation related. >> > > Do you mean 800M? ;) Highmem begins at 896MB if I remember correctly. > > Anyway, it still oopses on current git with mem=800M > > Stumped. Please post .config, will try to reproduce. >>> I was seeing messages like this >>> >>> [ 428.918108] kvm_handle_exit: unexpected, valid vectoring info and exit reason is 0x9 >>> >>> And quite a few of them, like 100,000/sec. That's why klogd was pegging >>> the CPU. Any idea on a next debugging step? >>> >>> >> That's a task switch. Newer kvms handle them. >> > > Newer userspace? I'm running current kvm-git userspace as of a day or > two ago. > No, it's kernel code. -- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain.