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=-7.9 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,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 1C6E2C433E7 for ; Thu, 3 Sep 2020 07:28:02 +0000 (UTC) Received: from silver.osuosl.org (smtp3.osuosl.org [140.211.166.136]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id D68DE20737 for ; Thu, 3 Sep 2020 07:28:01 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D68DE20737 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by silver.osuosl.org (Postfix) with ESMTP id 8E10B20470; Thu, 3 Sep 2020 07:28:01 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from silver.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id CP-x9aw4k+P1; Thu, 3 Sep 2020 07:27:59 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by silver.osuosl.org (Postfix) with ESMTP id 9ACF820450; Thu, 3 Sep 2020 07:27:59 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 71C9CC0052; Thu, 3 Sep 2020 07:27:59 +0000 (UTC) Received: from whitealder.osuosl.org (smtp1.osuosl.org [140.211.166.138]) by lists.linuxfoundation.org (Postfix) with ESMTP id 00815C0051 for ; Thu, 3 Sep 2020 07:27:57 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by whitealder.osuosl.org (Postfix) with ESMTP id EA14086B10 for ; Thu, 3 Sep 2020 07:27:57 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from whitealder.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 1JoZGQKclaJG for ; Thu, 3 Sep 2020 07:27:57 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mga12.intel.com (mga12.intel.com [192.55.52.136]) by whitealder.osuosl.org (Postfix) with ESMTPS id 33F3486B0B for ; Thu, 3 Sep 2020 07:27:57 +0000 (UTC) IronPort-SDR: cxX1y1M0jH6oYNFSOhfoc4zu+Ip/TLajzjkk5r9X/T4xeZmDzzNHaSukPn9hPdCgAde8YGRm2k 4meHCUHtUhxg== X-IronPort-AV: E=McAfee;i="6000,8403,9732"; a="137051399" X-IronPort-AV: E=Sophos;i="5.76,385,1592895600"; d="scan'208";a="137051399" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Sep 2020 00:27:56 -0700 IronPort-SDR: Ze3ZybqgmXXV2HST0KQmgul6uR9hAPh6E6UsMzLx6EMFfvZfUTDbVKkqtQmSz+4SUv5x0FohOJ g/eqXS3+PNow== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.76,385,1592895600"; d="scan'208";a="326108998" Received: from allen-box.sh.intel.com (HELO [10.239.159.139]) ([10.239.159.139]) by fmsmga004.fm.intel.com with ESMTP; 03 Sep 2020 00:27:53 -0700 Subject: =?UTF-8?B?UmU6IOetlOWkjTog562U5aSNOiBbUEFUQ0ggdjMgMi8yXSBpb21tdS92?= =?UTF-8?Q?t-d=3aAdd_support_for_probing_ACPI_device_in_RMRR?= To: FelixCui-oc , Joerg Roedel , "iommu@lists.linux-foundation.org" , "linux-kernel@vger.kernel.org" , David Woodhouse , Dan Carpenter , "kbuild@lists.01.org" References: <20200827100217.21324-1-FelixCui-oc@zhaoxin.com> <20200827100217.21324-3-FelixCui-oc@zhaoxin.com> <7e5f2c33-c6c3-f344-9014-1f6a306c55aa@linux.intel.com> From: Lu Baolu Message-ID: <56fc76e5-a31c-36b6-c6f0-fd8370cd7a91@linux.intel.com> Date: Thu, 3 Sep 2020 15:22:14 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US Cc: Ashok Raj , Tony W Wang-oc , CobeChen-oc X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" Hi Felix, On 9/2/20 11:24 AM, FelixCui-oc wrote: > hi baolu, > >> So you have a hidden device (invisible to host kernel). But you need to > >>setup some identity mappings for this device, so that the firmware >>could keep working, right? > >>The platform designs this by putting that range in the RMRR table and >>expecting the OS kernel to setup identity mappings during boot. > >>Do I understand it right? > > > Yes. What you understand is correct. This appears to be a new usage model of RMRR. I need to discuss this with the VT-d spec maintainer. Do you mind telling which platform are you going to run this on? What is the motivation of creating such hidden device? Basically, RMRRs were added as work around for certain legacy device and we have been working hard to fix those legacy devices so that RMRR are no longer needed. Best regards, baolu _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu