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=-15.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable 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 9E9E8C48BE8 for ; Fri, 18 Jun 2021 07:49:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7F7116120A for ; Fri, 18 Jun 2021 07:49:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233309AbhFRHwB (ORCPT ); Fri, 18 Jun 2021 03:52:01 -0400 Received: from frasgout.his.huawei.com ([185.176.79.56]:3266 "EHLO frasgout.his.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231418AbhFRHv7 (ORCPT ); Fri, 18 Jun 2021 03:51:59 -0400 Received: from fraeml742-chm.china.huawei.com (unknown [172.18.147.207]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4G5rMm1F1mz6G9tV; Fri, 18 Jun 2021 15:36:36 +0800 (CST) Received: from lhreml724-chm.china.huawei.com (10.201.108.75) by fraeml742-chm.china.huawei.com (10.206.15.223) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Fri, 18 Jun 2021 09:49:48 +0200 Received: from [10.47.95.81] (10.47.95.81) by lhreml724-chm.china.huawei.com (10.201.108.75) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Fri, 18 Jun 2021 08:49:47 +0100 Subject: Re: [PATCH v13 1/6] iommu: Deprecate Intel and AMD cmdline methods to enable strict mode To: Robin Murphy , , , , , CC: , , , , , References: <1623841437-211832-1-git-send-email-john.garry@huawei.com> <1623841437-211832-2-git-send-email-john.garry@huawei.com> From: John Garry Message-ID: Date: Fri, 18 Jun 2021 08:43:32 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.1.2 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-Originating-IP: [10.47.95.81] X-ClientProxiedBy: lhreml743-chm.china.huawei.com (10.201.108.193) To lhreml724-chm.china.huawei.com (10.201.108.75) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 17/06/2021 20:01, Robin Murphy wrote: >>               DMA. >> -        strict [Default Off] >> +        strict [Default Off] [Deprecated, use iommu.strict instead] >>               With this option on every unmap_single operation will >>               result in a hardware IOTLB flush operation as opposed >>               to batching them for performance. > > FWIW I'd be inclined to replace both whole descriptions with just > something like "Deprecated, equivalent to iommu.strict=1". > >> diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c >> index 46280e6e1535..9f3096d650aa 100644 >> --- a/drivers/iommu/amd/init.c >> +++ b/drivers/iommu/amd/init.c >> @@ -3098,8 +3098,10 @@ static int __init parse_amd_iommu_intr(char *str) >>   static int __init parse_amd_iommu_options(char *str) >>   { >>       for (; *str; ++str) { >> -        if (strncmp(str, "fullflush", 9) == 0) >> +        if (strncmp(str, "fullflush", 9) == 0) { >> +            pr_warn("amd_iommu=fullflush deprecated; use iommu.strict >> instead\n"); > > Nit: maybe we should spell out "...use