From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH]: pointer to vmcs getting lost Date: Mon, 11 Aug 2008 14:48:13 +0300 Message-ID: <48A026FD.3090003@qumranet.com> References: <48938BCC.2030402@neuraliq.com> <20080801232411.GA3486@dmt.cnet> <48939DE3.5070504@neuraliq.com> <20080802163144.GB17170@dmt.cnet> <4894F7CA.1040901@neuraliq.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Marcelo Tosatti , kvm@vger.kernel.org To: Jesse Return-path: Received: from il.qumranet.com ([212.179.150.194]:39215 "EHLO il.qumranet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750781AbYHKLsP (ORCPT ); Mon, 11 Aug 2008 07:48:15 -0400 In-Reply-To: <4894F7CA.1040901@neuraliq.com> Sender: kvm-owner@vger.kernel.org List-ID: Jesse wrote: > Marcelo Tosatti wrote: >> Do you have preempt notifiers enabled in your host kernel? >> > > No. And it looks like this is the real issue then. (Thank you for > reading between the lines and figuring out what was really wrong). > > I compile the module apart from the kernel, so kvm support was not > enabled when compiling the kernel. In 2.6.24, the PREEMPT_NOTIFIER > option is not user selectable in make config, but is selected for you > when kvm support is selected. IMO, this makes building modules apart > from kernel source unadvised; however, there seems to be no alternative > with the pace of kvm development relative to the kernel release schedule. If the host kernel doesn't have preempt notifiers enabled, then the kvm external module emulates preempt notifiers. This emulation uses the debug registers, and you mention that you are debugging guests, so that may be the source of the problem.