From patchwork Wed Jul 21 18:20:30 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Robin Murphy X-Patchwork-Id: 12391913 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=-18.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 832D7C12002 for ; Wed, 21 Jul 2021 18:33:20 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 41FF161245 for ; Wed, 21 Jul 2021 18:33:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 41FF161245 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=r3WjwgLG+ywLsw2mSEn7GoCasLhfW9P64bhQ+FJWh4M=; b=rYO60hqpnu4WZq ch3fRrAOavSxqPhcBAYMjlz+prLTKZyWsHUpO91VWcRBnhT199u0JB8mKm0k7qmdaLEWwg0hoK7ms aCu+q6GGnQNgxKYmIgOEJ3EQhL3ZERDErjcT7Dahyzt/BhKJymnt0+eIM1hK0lpzdA/NPAEp79LX7 dnPypXEh1ZkiWzUUKXyBsjRdQThYknAZDkdaah5oHPSYaR23jkHwdaPpNtVe0DnOtX6IglZRLlKFd ofyIDM14QWYMqWhLa83UEZJEo8wpbP/ZXRGVlFLXdZhHRGRbROHV4nLZWZpw4PCSSNKKBvPaRdxxj /4jefBaWyeWry4NvkhPQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1m6H0A-00GuKW-Go; Wed, 21 Jul 2021 18:31:27 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1m6GqN-00GpTD-Ma for linux-arm-kernel@lists.infradead.org; Wed, 21 Jul 2021 18:21:21 +0000 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 6A3F411FB; Wed, 21 Jul 2021 11:21:18 -0700 (PDT) Received: from 010265703453.arm.com (unknown [10.57.36.146]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id EC58A3F694; Wed, 21 Jul 2021 11:21:16 -0700 (PDT) From: Robin Murphy To: joro@8bytes.org, will@kernel.org Cc: iommu@lists.linux-foundation.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, suravee.suthikulpanit@amd.com, baolu.lu@linux.intel.com, john.garry@huawei.com, dianders@chromium.org Subject: [PATCH 19/23] iommu: Expose DMA domain strictness via sysfs Date: Wed, 21 Jul 2021 19:20:30 +0100 Message-Id: X-Mailer: git-send-email 2.25.1 In-Reply-To: References: MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210721_112119_808923_FEA93C3B X-CRM114-Status: GOOD ( 12.83 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org The sysfs interface for default domain types exists primarily so users can choose the performance/security tradeoff relevant to their own workload. As such, the choice between the policies for DMA domains fits perfectly as an additional point on that scale - downgrading a particular device from a strict default to non-strict may be enough to let it reach the desired level of performance, while still retaining more peace of mind than with a wide-open identity domain. Now that we've abstracted non-strict mode as a distinct type of DMA domain, allow it to be chosen through the user interface as well. Signed-off-by: Robin Murphy --- Documentation/ABI/testing/sysfs-kernel-iommu_groups | 2 ++ drivers/iommu/iommu.c | 2 ++ 2 files changed, 4 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-kernel-iommu_groups b/Documentation/ABI/testing/sysfs-kernel-iommu_groups index eae2f1c1e11e..43ba764ba5b7 100644 --- a/Documentation/ABI/testing/sysfs-kernel-iommu_groups +++ b/Documentation/ABI/testing/sysfs-kernel-iommu_groups @@ -42,6 +42,8 @@ Description: /sys/kernel/iommu_groups//type shows the type of default ======== ====================================================== DMA All the DMA transactions from the device in this group are translated by the iommu. + DMA-FQ As above, but using batched invalidation to lazily + remove translations after use. identity All the DMA transactions from the device in this group are not translated by the iommu. auto Change to the type the device was booted with. diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index d7eaacae0944..d3b562a33ac4 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -3195,6 +3195,8 @@ static ssize_t iommu_group_store_type(struct iommu_group *group, req_type = IOMMU_DOMAIN_IDENTITY; else if (sysfs_streq(buf, "DMA")) req_type = IOMMU_DOMAIN_DMA; + else if (sysfs_streq(buf, "DMA-FQ")) + req_type = IOMMU_DOMAIN_DMA_FQ; else if (sysfs_streq(buf, "auto")) req_type = 0; else