From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gerd Hoffmann Subject: Re: lapic & npt Date: Fri, 06 Jun 2008 16:45:22 +0200 Message-ID: <48494D82.4030803@redhat.com> References: <4846BEB8.1000208@redhat.com> <4846BFE0.8070507@qumranet.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org To: Avi Kivity Return-path: Received: from mx1.redhat.com ([66.187.233.31]:48912 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756529AbYFFOp1 (ORCPT ); Fri, 6 Jun 2008 10:45:27 -0400 In-Reply-To: <4846BFE0.8070507@qumranet.com> Sender: kvm-owner@vger.kernel.org List-ID: Avi Kivity wrote: > 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. Figured meanwhile the instruction accessing the lapic register somehow beames me into my gpf handler. With a quite strange rsp value. Hmm. To be analyzed further after kvm forum I guess, unless someone has a bright idea ... cheers, Gerd -- http://kraxel.fedorapeople.org/xenner/