From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755142Ab3BDSUb (ORCPT ); Mon, 4 Feb 2013 13:20:31 -0500 Received: from mx1.redhat.com ([209.132.183.28]:24256 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754984Ab3BDSU3 (ORCPT ); Mon, 4 Feb 2013 13:20:29 -0500 Date: Mon, 4 Feb 2013 13:20:15 -0500 From: Don Zickus To: Andy Lutomirski Cc: Gleb Natapov , Alex Williamson , x86@kernel.org, LKML , Suresh Siddha , "H. Peter Anvin" , Prarit Bhargava Subject: Re: [PATCH] intel_irq_remapping: Clean up x2apic optout security warning mess Message-ID: <20130204182015.GY98867@redhat.com> References: <510C3AF0.6050109@amacapital.net> <2011b943a886fd7c46079eb10bc24fc130587503.1359759303.git.luto@amacapital.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2011b943a886fd7c46079eb10bc24fc130587503.1359759303.git.luto@amacapital.net> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Feb 01, 2013 at 02:57:43PM -0800, Andy Lutomirski wrote: > Current kernels print this on my Dell server: > > ------------[ cut here ]------------ > WARNING: at drivers/iommu/intel_irq_remapping.c:542 > intel_enable_irq_remapping+0x7b/0x27e() > Hardware name: PowerEdge R620 > Your BIOS is broken and requested that x2apic be disabled > This will leave your machine vulnerable to irq-injection attacks > Use 'intremap=no_x2apic_optout' to override BIOS request > [...] > Enabled IRQ remapping in xapic mode > x2apic not enabled, IRQ remapping is in xapic mode > > This is inconsistent with itself -- interrupt remapping is *on*. > > Fix the mess by making the warnings say what they mean and my making > sure that compatibility format interrupts (the dangerous ones) are > disabled if x2apic is present regardless of BIOS settings. Yeah, this fixes the problem on our end too. Thank Andy! Cheers, Don