From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: BUG with Win7 and user-return-notifier Date: Thu, 29 Oct 2009 10:07:05 +0200 Message-ID: <4AE94D29.8030600@redhat.com> References: <4AE6ED18.9040901@siemens.com> <4AE6F17C.1070403@redhat.com> <4AE6F1EE.5090207@siemens.com> <4AE6F4A3.3050903@redhat.com> <4AE6F4C4.3000802@redhat.com> <4AE7FE3B.2070802@redhat.com> <4AE84EB4.1010603@siemens.com> <4AE86AA0.1060802@redhat.com> <4AE8AC20.50506@web.de> <4AE9462E.5050409@redhat.com> <4AE94C63.2070300@web.de> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: kvm-devel To: Jan Kiszka Return-path: Received: from mx1.redhat.com ([209.132.183.28]:27880 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752285AbZJ2IHF (ORCPT ); Thu, 29 Oct 2009 04:07:05 -0400 In-Reply-To: <4AE94C63.2070300@web.de> Sender: kvm-owner@vger.kernel.org List-ID: On 10/29/2009 10:03 AM, Jan Kiszka wrote: > Avi Kivity wrote: > >> On 10/28/2009 10:40 PM, Jan Kiszka wrote: >> >>> >>>> [you can get longer, more detailed traces by using >>>> /sys/kernel/debug/tracing/trace instead of dmesg] >>>> >>>> Oct 28 14:29:56 mchn012c kernel: qemu-sys-7200 0...1. 676996395us : >>>> kvm_msr: msr_read c0000080 = 0x500 >>>> Oct 28 14:29:56 mchn012c kernel: qemu-sys-7200 0...1. 676996403us : >>>> kvm_msr: msr_write c0000080 = 0xd01 >>>> >>>> So Windows is setting EFER.SCE and EFER.NX while in long mode - >>>> perfectly reasonable. Can you rerun with the attached debug patch? >>>> >>>> >>>> >>> Log attached. >>> >>> >> So the last bits are: >> >> Oct 28 21:26:41 mchn012c kernel: update_transition_efer: efer_offset 4 >> efer d01 >> Oct 28 21:26:41 mchn012c kernel: update_transition_efer: ignoring all bits >> Oct 28 21:26:41 mchn012c kernel: setup_msrs: marking efer for no reload >> >> We're not reloading efer (correctly, as guest efer == host efer), yet >> vmx_save_host_state() fails while loading efer. I've looked at >> move_msr_up() (which is used by setup_msrs() to partition the msr space >> into reloaded and non-reloaded msrs), and it seems correct. >> >> Can you see any way where update_transition_efer() returns false, yet >> efer turns up in the first save_nmsrs entries of vmx->guest_msrs? >> >> > Without understanding the code completely yet: When you push the slot > containing EFER around, do you also update msr_offset_efer? > > We don't, but msr_offset_efer is only used from update_transition_efer(), which is only ever called from setup_msrs() immediately after updating msr_offset_efer. Of course, it should be an argument to update_transition_efer(), I'll clean up this leftover. -- Do not meddle in the internals of kernels, for they are subtle and quick to panic.