From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: lapic & npt Date: Wed, 04 Jun 2008 19:16:32 +0300 Message-ID: <4846BFE0.8070507@qumranet.com> References: <4846BEB8.1000208@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org To: Gerd Hoffmann Return-path: Received: from bzq-179-150-194.static.bezeqint.net ([212.179.150.194]:31916 "EHLO il.qumranet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752517AbYFDQQ3 (ORCPT ); Wed, 4 Jun 2008 12:16:29 -0400 In-Reply-To: <4846BEB8.1000208@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: Gerd Hoffmann wrote: > Hi, > > I've just noticed that xenner doesn't work for 64bit xen guest kernels > on my new shiny barcelona box. The VM crashes when trying to access the > lapic. lapic setup is done before idt setup, register dump looks like > init state, thus it most likely is a triple fault resetting the vcpu. > Turning off npt fixes it. > > xenner maps the lapic to ffff820000000000 (64bit guests) or fe900000 > (32bit guests). 32bit works fine even with npt enabled. > > host kernel is fedora 9 with kvm-69 modules. > > ideas anyone? > > Turn on logging in lapic.c. See if something turns up. If not, the page tables are probably set up incorrectly, but in a way that kvm doesn't notice. -- Do not meddle in the internals of kernels, for they are subtle and quick to panic.