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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 8C073C3A5A4 for ; Tue, 27 Aug 2019 12:47:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 62AEC20828 for ; Tue, 27 Aug 2019 12:47:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729867AbfH0MrL (ORCPT ); Tue, 27 Aug 2019 08:47:11 -0400 Received: from mga18.intel.com ([134.134.136.126]:36325 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726170AbfH0MrL (ORCPT ); Tue, 27 Aug 2019 08:47:11 -0400 X-Amp-Result: UNSCANNABLE X-Amp-File-Uploaded: False Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga106.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 27 Aug 2019 05:47:10 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,437,1559545200"; d="scan'208";a="187907181" Received: from jsakkine-mobl1.fi.intel.com (HELO localhost) ([10.237.66.169]) by FMSMGA003.fm.intel.com with ESMTP; 27 Aug 2019 05:47:08 -0700 Date: Tue, 27 Aug 2019 15:47:07 +0300 From: Jarkko Sakkinen To: Matthew Garrett Cc: Seunghun Han , Matthew Garrett , Peter Huewe , "open list:TPM DEVICE DRIVER" , Linux Kernel Mailing List Subject: Re: [PATCH] x86: tpm: Remove a busy bit of the NVS area for supporting AMD's fTPM Message-ID: <20190827124707.yhqtaqa4ur6i45h7@linux.intel.com> References: <20190826081752.57258-1-kkamagui@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: NeoMutt/20180716 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Aug 26, 2019 at 10:40:25AM -0700, Matthew Garrett wrote: > On Mon, Aug 26, 2019 at 1:18 AM Seunghun Han wrote: > > To support AMD's fTPM, I removed the busy bit from the ACPI NVS area like > > the reserved area so that AMD's fTPM regions could be assigned in it. > > drivers/acpi/nvs.c saves and restores the contents of NVS regions, and > if other drivers use these regions without any awareness of this then > things may break. I'm reluctant to say that just unilaterally marking > these regions as available is a good thing, but it's clearly what's > expected by AMD's implementation. One approach would be to have a > callback into the nvs code to indicate that a certain region should be > handed off to a driver, which would ensure that we can handle this on > a case by case basis? What if E820 would just have a small piece of code just for fTPM's e.g. it would check the ACPI tree for fTPM's and ignore TPM regions. /Jarkko