From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755499AbbIAKEW (ORCPT ); Tue, 1 Sep 2015 06:04:22 -0400 Received: from ud10.udmedia.de ([194.117.254.50]:49519 "EHLO mail.ud10.udmedia.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754733AbbIAKEU (ORCPT ); Tue, 1 Sep 2015 06:04:20 -0400 Date: Tue, 1 Sep 2015 12:04:17 +0200 From: Markus Trippelsdorf To: Ingo Molnar Cc: Linus Torvalds , linux-kernel@vger.kernel.org, Peter Zijlstra , Thomas Gleixner , Andrew Morton , Mike Galbraith , Joerg Roedel , Paolo Bonzini , kvm@vger.kernel.org Subject: Re: commit 3c2e7f7de3 (KVM use NPT page attributes) causes boot failures Message-ID: <20150901100417.GA424@x4> References: <20150831172453.GA5429@gmail.com> <20150901070856.GA430@x4> <20150901072741.GB20383@gmail.com> <20150901074449.GB430@x4> <20150901083856.GD25398@gmail.com> <20150901084444.GB421@x4> <20150901085627.GF6315@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150901085627.GF6315@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2015.09.01 at 10:56 +0200, Ingo Molnar wrote: > > * Markus Trippelsdorf wrote: > > As I wrote in my other reply. The boot failure is nondeterministic (boot > > succeeds roughly every sixth time). So the bisection and the patch is > > just bogus (,but the boot failure is real). > > > > Sorry. > > No problem. Please let us know if any of these commits does turn out to be the > culprit. (Which is always a possibility.) I'm pretty sure commit 3c2e7f7de3 is the culprit. commit 3c2e7f7de3240216042b61073803b61b9b3cfb22 Author: Paolo Bonzini Date: Tue Jul 7 14:32:17 2015 +0200 KVM: SVM: use NPT page attributes I've booted ten times in a row successfully with the following patch: diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 74d825716f4f..3190173a575f 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -989,7 +989,7 @@ static __init int svm_hardware_setup(void) } else kvm_disable_tdp(); - build_mtrr2protval(); +// build_mtrr2protval(); return 0; err: Paolo, your commit causes nondeterministic boot failure on my machine. It sometimes crashes early with the following backtrace: map_vsyscall kvm_arch_hardware_setup map_vsyscall kvm_init map_vsyscall do_one_initcall kernel_init_freeable rest_init kernel_init ret_from_fork rest_init RIP: svm_hardware_setup -- Markus