From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.1 required=3.0 tests=DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,T_DKIM_INVALID, USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 26C6FC43143 for ; Thu, 21 Jun 2018 22:10:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CE9AB22486 for ; Thu, 21 Jun 2018 22:10:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="TZgjDB3X" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CE9AB22486 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933880AbeFUWKX (ORCPT ); Thu, 21 Jun 2018 18:10:23 -0400 Received: from merlin.infradead.org ([205.233.59.134]:35538 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933847AbeFUWKU (ORCPT ); Thu, 21 Jun 2018 18:10:20 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=Ca8rzZ+OWS6mKGTyc7UGktFUdHGEU2w5NG/1RrltHO4=; b=TZgjDB3XGLQSOP3JREMXOINbI TCeFNakLTedB8RrwI5EDihkhSuwKYrPinYmkGLBTsLrFUhWUGAbXqkzbAYH0wqDvi8OpyHFZadx8I rYixvQ2446GN5ldu97xAsxtGeoN/qZENmXQQT20rY4d99FxrEdUcN7rwLExfcsmyJq9FbgLEYppDe mqKx9wBqDdH+Zb/Z+Nj1IN3FLyS+ezDfnRhT3W0XphP23n3AhzhZ+oJbz4D/paL3tame7Mm6Kzchs zB5fgliH4rjIEnivgeyX4N/OHX4BmzTB+3GjPTYmnLcH1+nKzfB7qgBJLY/dMOoikci1V+Qp3uTko z4mA9+1xA==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1fW7mK-00030S-SU; Thu, 21 Jun 2018 22:10:09 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 4B9E62029F1D7; Fri, 22 Jun 2018 00:10:06 +0200 (CEST) Date: Fri, 22 Jun 2018 00:10:06 +0200 From: Peter Zijlstra To: Fenghua Yu Cc: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Ashok Raj , Dave Hansen , Rafael Wysocki , Tony Luck , Alan Cox , Ravi V Shankar , Arjan van de Ven , linux-kernel , x86 Subject: Re: [RFC PATCH 00/16] x86/split_lock: Enable #AC exception for split locked accesses Message-ID: <20180621221006.GC2494@hirez.programming.kicks-ass.net> References: <1527435965-202085-1-git-send-email-fenghua.yu@intel.com> <20180621193738.GA13636@worktop.programming.kicks-ass.net> <20180621201851.GC114883@romley-ivt3.sc.intel.com> <20180621220003.GD114883@romley-ivt3.sc.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180621220003.GD114883@romley-ivt3.sc.intel.com> User-Agent: Mutt/1.10.0 (2018-05-17) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 21, 2018 at 03:00:03PM -0700, Fenghua Yu wrote: > The control knob for firmware is to choose continuing firmware execution > by disabling #AC split lock (default) or stopping firmware execution > by enabling #AC for split lock. Stopping firmware execution may be useful > in hard real time system to identify any split lock issue on the platform. Having the option only allows broken firmware to continue to exist. Limiting people in how they can use their machines.