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=-15.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 96800C48BE6 for ; Mon, 14 Jun 2021 15:05:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7C16B61352 for ; Mon, 14 Jun 2021 15:05:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233379AbhFNPH3 (ORCPT ); Mon, 14 Jun 2021 11:07:29 -0400 Received: from foss.arm.com ([217.140.110.172]:38202 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232869AbhFNPHZ (ORCPT ); Mon, 14 Jun 2021 11:07:25 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 6547B1FB; Mon, 14 Jun 2021 08:05:22 -0700 (PDT) Received: from [10.57.9.136] (unknown [10.57.9.136]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id DECD13F70D; Mon, 14 Jun 2021 08:05:20 -0700 (PDT) Subject: Re: [PATCH v12 3/5] iommu/vt-d: Add support for IOMMU default DMA mode build options To: John Garry , Lu Baolu , "joro@8bytes.org" , "will@kernel.org" , "dwmw2@infradead.org" Cc: "linux-kernel@vger.kernel.org" , "iommu@lists.linux-foundation.org" , Linuxarm , "Leizhen (ThunderTown)" , "chenxiang (M)" References: <1623414043-40745-1-git-send-email-john.garry@huawei.com> <1623414043-40745-4-git-send-email-john.garry@huawei.com> <4f2cec34-bad9-e1bf-85c1-04d1a0c1aecf@linux.intel.com> <6055cd0d-a1d3-a73a-6831-3837021f3c9c@huawei.com> <0a04f964-80f4-7b2a-9740-eae4596e4e09@arm.com> <453a4606-099c-3d06-13fd-dc29c24230f5@huawei.com> From: Robin Murphy Message-ID: Date: Mon, 14 Jun 2021 16:05:15 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:78.0) Gecko/20100101 Thunderbird/78.10.1 MIME-Version: 1.0 In-Reply-To: <453a4606-099c-3d06-13fd-dc29c24230f5@huawei.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2021-06-14 15:19, John Garry wrote: > On 14/06/2021 15:11, Robin Murphy wrote: >> On 2021-06-14 08:53, John Garry wrote: >>> On 12/06/2021 03:22, Lu Baolu wrote: >>>> On 2021/6/11 20:20, John Garry wrote: >>>>> @@ -453,8 +452,7 @@ static int __init intel_iommu_setup(char *str) >>>>>                pr_warn("intel_iommu=forcedac deprecated; use >>>>> iommu.forcedac instead\n"); >>>>>                iommu_dma_forcedac = true; >>>>>            } else if (!strncmp(str, "strict", 6)) { >>>>> -            pr_info("Disable batched IOTLB flush\n"); >>>>> -            intel_iommu_strict = 1; >>>>> +            iommu_set_dma_strict(true); >>>> I would like to deprecate this command line and ask users to use >>>> iommu.strict instead. >>> ok, but then I should probably make the AMD driver also officially >>> support this. >> Oops, I should have documented that "iommu.strict" already applies to >> x86 as well. The interaction with the driver-specific parameters is a >> bit weird and unintuitive, but it was done knowingly. Let me quickly >> spin a kernel-parameters.txt fix for that... > > So I already had a pending patch here for the same to be included in > this series: > https://github.com/hisilicon/kernel-dev/commit/2375a2d888d78de9eb7d91d6f2c5891395300a96 > > > If you want to do it, then ok. I might have to reorder the series though... Yeah, sorry for the complication. Your subsequent deprecation of the x86 parameters doesn't need to conflict, but we should probably also update that the default value now depends on the kernel config, which will :( Thanks, Robin.