From patchwork Wed Jul 28 15:58:40 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Robin Murphy X-Patchwork-Id: 12406291 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=-17.5 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,URIBL_BLOCKED, 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 56EE4C4338F for ; Wed, 28 Jul 2021 16:11:52 +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 28CAB604DB for ; Wed, 28 Jul 2021 16:11:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 28CAB604DB Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=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=BJN3kYqe4RWb4nY9u0V9/+N3/r676qr/UjGeCQsSRjA=; b=pZqfxgGMT5nD9W uw4H2iZ9PB43KCtK/mIT8nkJMEsNZ9Cf2OmBgo/DNuOoefjEAmGteMEY5C1KCkAUpOQpor2bJ72w8 9ZjhfVNmOigyfy81rE7hveFInV4kbKfAdgFFHwq8fVlKtZxbVspdOFQyY+96iwdKs2JqnRhk736Rx DSoIvgo1zELaVXq5okwKz/Vl6RyAWi9KkUT6yFGjvAn+ITGQ9nONdkncEYgUtApxxGyXsWZi0lV+0 vT6gEV4NWU/UWHbO9GQes3ZmMdtksB5QmHLe05TepRP424Ca24WcuywjkmZRR6UMz2iFeWfaY+RL/ yxtHil/i3RsxIH4TNU6A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1m8m79-001Uul-LF; Wed, 28 Jul 2021 16:08:59 +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 1m8ly8-001POU-EZ for linux-arm-kernel@lists.infradead.org; Wed, 28 Jul 2021 15:59:42 +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 EC2A7D6E; Wed, 28 Jul 2021 08:59:39 -0700 (PDT) Received: from 010265703453.arm.com (unknown [10.57.36.146]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 799E73F70D; Wed, 28 Jul 2021 08:59:38 -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 v2 19/24] iommu: Expose DMA domain strictness via sysfs Date: Wed, 28 Jul 2021 16:58:40 +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-20210728_085940_601691_58D69F6D X-CRM114-Status: GOOD ( 12.65 ) 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 Reviewed-by: Lu Baolu Reviewed-by: John Garry --- 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 eecb5657de69..5a08e0806cbb 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -3265,6 +3265,8 @@ 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