From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from terminus.zytor.com ([2001:1868:205::10] helo=mail.zytor.com) by casper.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1S7BSy-0001LB-0X for kexec@lists.infradead.org; Mon, 12 Mar 2012 20:03:38 +0000 Message-ID: <4F5E566D.9060209@zytor.com> Date: Mon, 12 Mar 2012 13:02:53 -0700 From: "H. Peter Anvin" MIME-Version: 1.0 Subject: Re: [PATCH 1/2] boot: ignore early NMIs References: <4F573E1C.2060909@oss.ntt.co.jp> <4F573E74.5040504@oss.ntt.co.jp> <4F58495B.5080308@oss.ntt.co.jp> <4F5A6D87.4050809@zytor.com> <4F5D8D0E.8060702@oss.ntt.co.jp> <4F5D8E63.60606@zytor.com> <4F5D943C.5020403@oss.ntt.co.jp> <20120312133619.GB17288@redhat.com> In-Reply-To: List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: kexec-bounces@lists.infradead.org Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: "Eric W. Biederman" Cc: Don Zickus , akpm@linux-foundation.org, linux-tip-commits@vger.kernel.org, Yinghai Lu , =?UTF-8?B?RmVybmFuZG8gTHVpcyBWw6F6cXU=?= =?UTF-8?B?ZXogQ2Fv?= , kexec@lists.infradead.org, linux-kernel@vger.kernel.org, mingo@redhat.com, tglx@linutronix.de, torvalds@linux-foundation.org, mingo@elte.hu, Vivek Goyal On 03/12/2012 12:02 PM, Eric W. Biederman wrote: > > Disabling NMI generation in the LAPIC is fine, and for the short term > I don't even have a problem with disabling the entire LAPIC as all of > our platforms seem to have code for completely reprogramming it. > > At the same time there have been cases like the i8259 routed through > the ExtInt pin of the lapci that we haven't been given programming > information about and that if we want to work we should avoid touching. > I'm pretty sure that information is in the SDM (I'm looking at it now.) You can also block NMI though this route, since external NMI really is LINT1 and hence is routed through the LAPIC; you can mask it by clearing bit 16 in LVT LINT1 as described in the SDM. -hpa _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757006Ab2CLUDm (ORCPT ); Mon, 12 Mar 2012 16:03:42 -0400 Received: from terminus.zytor.com ([198.137.202.10]:52461 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756473Ab2CLUDl (ORCPT ); Mon, 12 Mar 2012 16:03:41 -0400 Message-ID: <4F5E566D.9060209@zytor.com> Date: Mon, 12 Mar 2012 13:02:53 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:10.0.1) Gecko/20120209 Thunderbird/10.0.1 MIME-Version: 1.0 To: "Eric W. Biederman" CC: Vivek Goyal , =?UTF-8?B?RmVybmFuZG8gTHVpcyBWw6F6cXU=?= =?UTF-8?B?ZXogQ2Fv?= , Don Zickus , linux-tip-commits@vger.kernel.org, torvalds@linux-foundation.org, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, mingo@redhat.com, tglx@linutronix.de, mingo@elte.hu, Yinghai Lu , akpm@linux-foundation.org Subject: Re: [PATCH 1/2] boot: ignore early NMIs References: <4F573E1C.2060909@oss.ntt.co.jp> <4F573E74.5040504@oss.ntt.co.jp> <4F58495B.5080308@oss.ntt.co.jp> <4F5A6D87.4050809@zytor.com> <4F5D8D0E.8060702@oss.ntt.co.jp> <4F5D8E63.60606@zytor.com> <4F5D943C.5020403@oss.ntt.co.jp> <20120312133619.GB17288@redhat.com> In-Reply-To: X-Enigmail-Version: 1.3.5 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/12/2012 12:02 PM, Eric W. Biederman wrote: > > Disabling NMI generation in the LAPIC is fine, and for the short term > I don't even have a problem with disabling the entire LAPIC as all of > our platforms seem to have code for completely reprogramming it. > > At the same time there have been cases like the i8259 routed through > the ExtInt pin of the lapci that we haven't been given programming > information about and that if we want to work we should avoid touching. > I'm pretty sure that information is in the SDM (I'm looking at it now.) You can also block NMI though this route, since external NMI really is LINT1 and hence is routed through the LAPIC; you can mask it by clearing bit 16 in LVT LINT1 as described in the SDM. -hpa