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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,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 5A026C433ED for ; Wed, 12 May 2021 04:47:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1DEEE6187E for ; Wed, 12 May 2021 04:47:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230011AbhELEsw (ORCPT ); Wed, 12 May 2021 00:48:52 -0400 Received: from mga12.intel.com ([192.55.52.136]:61438 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229495AbhELEsu (ORCPT ); Wed, 12 May 2021 00:48:50 -0400 IronPort-SDR: lm5mruyCjAlZqTVgzWpdSsTzOyC6YCzGB8DaNBHbu+lOyy9ggQAzCOZH4Wv1ZvOlOUFbzbFcMH iIjOqbtQ8OlA== X-IronPort-AV: E=McAfee;i="6200,9189,9981"; a="179210148" X-IronPort-AV: E=Sophos;i="5.82,293,1613462400"; d="scan'208";a="179210148" Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 May 2021 21:47:41 -0700 IronPort-SDR: 53J1wazrS1QReixwdHkkxnR6h55hKjKPB+/AHJbpqmNp4e/76VbGCJhC1SNjmVaypT58hu5x5h SX50P3VhkV8A== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.82,292,1613462400"; d="scan'208";a="622109218" Received: from allen-box.sh.intel.com (HELO [10.239.159.128]) ([10.239.159.128]) by fmsmga006.fm.intel.com with ESMTP; 11 May 2021 20:21:05 -0700 Cc: baolu.lu@linux.intel.com, Alex Williamson , Kirti Wankhede , Cornelia Huck , Jonathan Cameron , wanghaibin.wang@huawei.com, jiangkunkun@huawei.com, yuzenghui@huawei.com, lushenming@huawei.com Subject: Re: [RFC PATCH v4 01/13] iommu: Introduce dirty log tracking framework To: Keqian Zhu , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, iommu@lists.linux-foundation.org, Robin Murphy , Will Deacon , Joerg Roedel , Jean-Philippe Brucker , Yi Sun , Tian Kevin References: <20210507102211.8836-1-zhukeqian1@huawei.com> <20210507102211.8836-2-zhukeqian1@huawei.com> <18ac787a-179e-71f7-728b-c43feda80a16@huawei.com> <55fda826-9ab6-a3a0-b17e-a4d4879f00bc@linux.intel.com> <60182a35-e151-7150-3708-4e58dd8e78da@huawei.com> From: Lu Baolu Message-ID: <36cc7267-6aa3-db54-b08c-c2dfc0bbacb6@linux.intel.com> Date: Wed, 12 May 2021 11:20:18 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.7.1 MIME-Version: 1.0 In-Reply-To: <60182a35-e151-7150-3708-4e58dd8e78da@huawei.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 5/11/21 3:40 PM, Keqian Zhu wrote: >> For upper layers, before starting page tracking, they check the >> dirty_page_trackable attribution of the domain and start it only it's >> capable. Once the page tracking is switched on the vendor iommu driver >> (or iommu core) should block further device attach/detach operations >> until page tracking is stopped. > But when a domain becomes capable after detaching a device, the upper layer > still needs to query it and enable dirty log for it... > > To make things coordinated, maybe the upper layer can register a notifier, > when the domain's capability change, the upper layer do not need to query, instead > they just need to realize a callback, and do their specific policy in the callback. > What do you think? > That might be an option. But why not checking domain's attribution every time a new tracking period is about to start? Best regards, baolu