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=-15.9 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=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 CB735C47082 for ; Fri, 4 Jun 2021 02:54:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B186461246 for ; Fri, 4 Jun 2021 02:54:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229820AbhFDC42 (ORCPT ); Thu, 3 Jun 2021 22:56:28 -0400 Received: from szxga03-in.huawei.com ([45.249.212.189]:4344 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229576AbhFDC41 (ORCPT ); Thu, 3 Jun 2021 22:56:27 -0400 Received: from dggemv711-chm.china.huawei.com (unknown [172.30.72.53]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4Fx6hY2SGcz68Tn; Fri, 4 Jun 2021 10:50:53 +0800 (CST) Received: from dggpemm500006.china.huawei.com (7.185.36.236) by dggemv711-chm.china.huawei.com (10.1.198.66) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Fri, 4 Jun 2021 10:54:32 +0800 Received: from [127.0.0.1] (10.174.177.72) by dggpemm500006.china.huawei.com (7.185.36.236) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Fri, 4 Jun 2021 10:54:32 +0800 Subject: Re: [PATCH v10 1/3] iommu: Enhance IOMMU default DMA mode build options To: John Garry , , , , , CC: , , , References: <1622728715-209296-1-git-send-email-john.garry@huawei.com> <1622728715-209296-2-git-send-email-john.garry@huawei.com> From: "Leizhen (ThunderTown)" Message-ID: <0e54ff0f-c668-354e-1ec8-7536c701d3a8@huawei.com> Date: Fri, 4 Jun 2021 10:54:30 +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: <1622728715-209296-2-git-send-email-john.garry@huawei.com> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.177.72] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To dggpemm500006.china.huawei.com (7.185.36.236) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2021/6/3 21:58, John Garry wrote: > From: Zhen Lei > > First, add build options IOMMU_DEFAULT_{LAZY|STRICT}, so that we have the > opportunity to set {lazy|strict} mode as default at build time. Then put > the two config options in an choice, as they are mutually-exclusive. > > [jpg: Make choice between strict and lazy only (and not passthrough)] > Signed-off-by: Zhen Lei > Signed-off-by: John Garry > --- > drivers/iommu/Kconfig | 34 ++++++++++++++++++++++++++++++++++ > drivers/iommu/iommu.c | 3 ++- > 2 files changed, 36 insertions(+), 1 deletion(-) > > diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig > index 1f111b399bca..12ef90256df8 100644 > --- a/drivers/iommu/Kconfig > +++ b/drivers/iommu/Kconfig > @@ -90,6 +90,40 @@ config IOMMU_DEFAULT_PASSTHROUGH > > If unsure, say N here. > > +choice > + prompt "IOMMU default DMA mode" > + depends on IOMMU_API config INTEL_IOMMU depends on PCI_MSI && ACPI && (X86 || IA64) config AMD_IOMMU depends on X86_64 && PCI && ACPI && HAVE_CMPXCHG_DOUBLE config ARM_SMMU_V3 depends on ARM64 "depends on ARM_SMMU_V3 || INTEL_IOMMU || AMD_IOMMU" may need to be added, because it doesn't work on other platforms. or "depends on X86 || IA64 || X86_64 || ARM64" > + > + default IOMMU_DEFAULT_STRICT > + help > + This option allows an IOMMU DMA mode to be chosen at build time, to > + override the default DMA mode of each ARCH, removing the need to > + pass in kernel parameters through command line. It is still possible > + to provide ARCH-specific or common boot options to override this > + option. > + > + If unsure, keep the default. > + > +config IOMMU_DEFAULT_LAZY > + bool "lazy" > + help > + Support lazy mode, where for every IOMMU DMA unmap operation, the > + flush operation of IOTLB and the free operation of IOVA are deferred. > + They are only guaranteed to be done before the related IOVA will be > + reused. > + > +config IOMMU_DEFAULT_STRICT > + bool "strict" > + help > + For every IOMMU DMA unmap operation, the flush operation of IOTLB and > + the free operation of IOVA are guaranteed to be done in the unmap > + function. > + > + This mode is safer than the two above, but it maybe slower in some > + high performace scenarios. > + > +endchoice > + > config OF_IOMMU > def_bool y > depends on OF && IOMMU_API > diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c > index 966426a96520..177b0dafc535 100644 > --- a/drivers/iommu/iommu.c > +++ b/drivers/iommu/iommu.c > @@ -29,7 +29,8 @@ static struct kset *iommu_group_kset; > static DEFINE_IDA(iommu_group_ida); > > static unsigned int iommu_def_domain_type __read_mostly; > -static bool iommu_dma_strict __read_mostly = true; > +static bool iommu_dma_strict __read_mostly = > + IS_ENABLED(CONFIG_IOMMU_DEFAULT_STRICT); Currently, a maximum of 100 columns are allowed in a row. > static u32 iommu_cmd_line __read_mostly; > > struct iommu_group { >