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 5F058C433E0 for ; Wed, 27 Jan 2021 05:59:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 333342072D for ; Wed, 27 Jan 2021 05:59:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232758AbhA0F6w (ORCPT ); Wed, 27 Jan 2021 00:58:52 -0500 Received: from szxga07-in.huawei.com ([45.249.212.35]:11897 "EHLO szxga07-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233052AbhA0DSC (ORCPT ); Tue, 26 Jan 2021 22:18:02 -0500 Received: from DGGEMS406-HUB.china.huawei.com (unknown [172.30.72.60]) by szxga07-in.huawei.com (SkyGuard) with ESMTP id 4DQRdZ1nkLz7bgc; Wed, 27 Jan 2021 10:00:34 +0800 (CST) Received: from [127.0.0.1] (10.174.176.220) by DGGEMS406-HUB.china.huawei.com (10.3.19.206) with Microsoft SMTP Server id 14.3.498.0; Wed, 27 Jan 2021 10:01:35 +0800 Subject: Re: [PATCH 1/1] iommu/arm-smmu-v3: add support for BBML To: Will Deacon , Robin Murphy CC: Joerg Roedel , Jean-Philippe Brucker , Jonathan Cameron , linux-arm-kernel , iommu , linux-kernel , Yang Yingliang References: <20201126034230.777-1-thunder.leizhen@huawei.com> <20210122125132.GB24102@willie-the-truck> <1bfd1ca0-953e-e943-f87e-144d5537bd0c@arm.com> <20210126101230.GA29204@willie-the-truck> From: "Leizhen (ThunderTown)" Message-ID: <8a9685ec-67aa-824f-5429-f408bf79c5ab@huawei.com> Date: Wed, 27 Jan 2021 10:01:34 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: <20210126101230.GA29204@willie-the-truck> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.176.220] X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2021/1/26 18:12, Will Deacon wrote: > On Mon, Jan 25, 2021 at 08:23:40PM +0000, Robin Murphy wrote: >> Now we probably will need some degreee of BBML feature awareness for the >> sake of SVA if and when we start using it for CPU pagetables, but I still >> cannot see any need to consider it in io-pgtable. > > Agreed; I don't think this is something that io-pgtable should have to care > about. Yes, the SVA works in stall mode, and the failed device access requests are not discarded. Let me look for examples. The BBML usage scenario was told by a former colleague. > > Will > > . >