Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755735Ab1FIDUv (ORCPT ); Wed, 8 Jun 2011 23:20:51 -0400 Received: from mga03.intel.com ([143.182.124.21]:57758 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754457Ab1FIDUt (ORCPT ); Wed, 8 Jun 2011 23:20:49 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.65,340,1304319600"; d="scan'208";a="9653522" Date: Thu, 9 Jun 2011 11:34:32 -0400 From: Youquan Song To: "Woodhouse, David" , Ingo Molnar Cc: Thomas Gleixner , Ingo Molnar , "Song, Youquan" , "linux-kernel@vger.kernel.org" , "akpm@linux-foundation.org" , "hpa@zytor.com" , "hpa@linux.intel.com" , "Kay, Allen M" , "Siddha, Suresh B" , "Sankaran, Rajesh" , "Mallick, Asit K" , "Liu, Kent" , Youquan Song Subject: Re: [PATCH v4] x86, vt-d: enable x2apic opt out Message-ID: <20110609153432.GA12741@linux-youquan.bj.intel.com> References: <1306341418-10645-1-git-send-email-youquan.song@intel.com> <20110525205843.GC28397@elte.hu> <1306366670.2029.46.camel@i7.infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1306366670.2029.46.camel@i7.infradead.org> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1012 Lines: 28 > Is that going to make these broken BIOSes fall over too? If so, it > really does look like the placement of this bit in the DMAR table is > entirely wrong. > > Rajesh, can you tell use *exactly* what is the BIOS brokenness that this > hack was invented to work around? > Hi Ingo and David, IMO, the OPT-OUT flag is not good solution to workround BIOS or platform issues. But some custmoers really requires it to 1) meet their business target. 2) some components in OEM platforms have issue if they generate platform-events like SMI, or SMM handlers, some interrupt from LAPIC, because they does not go through VT-d,so they do not know CPU in x2APIC or xAPIC. Can you take it to maintainer tree? It will be better for OSVs integration. Thanks -Youquan -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/