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=-16.1 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,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 16F50C4338F for ; Fri, 30 Jul 2021 06:14:59 +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 D8F2A60F4B for ; Fri, 30 Jul 2021 06:14:58 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org D8F2A60F4B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.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-Type: Content-Transfer-Encoding:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date:Message-ID:From: References:To:Subject:Cc:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=/sCY+iRWyu13TMDiyJxWEOIVWVqnCb9T3bSauj/QE0w=; b=1R1MkrNBNIsy+45dWOauGox9nb lklW54RcKWjD1rW0qlJcdE8jlJh9WuVViPbdgEAfgd1XGt+yfb5QXKpjqeZHvYZD4QJ9lkkqSvFDO d9aOtxg+TCys6dvFe0TuF0lRreOhOJPKzQzqCmQzDfGm4olZtWFcCYxs/8ZHAv1eFdY0lf/Bw6dUS MQYuuABHc3neIL7EaYONaWpxjmdKCPWI4Y55OD8vuBwMv9tm7d8AJ82DP949HSaDQS2oItJ9v6QVz wkdu+mVL+CmdvtmSuqnbLbJlB0COAlgBewSorIlQ+nZzFIagtP+W6hqtdyCwBI+KzeTFVvqO1hFrT JalmMAIQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1m9LlV-007P6n-58; Fri, 30 Jul 2021 06:13:01 +0000 Received: from mga03.intel.com ([134.134.136.65]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1m9LlJ-007P50-CO for linux-arm-kernel@lists.infradead.org; Fri, 30 Jul 2021 06:12:50 +0000 X-IronPort-AV: E=McAfee;i="6200,9189,10060"; a="213070255" X-IronPort-AV: E=Sophos;i="5.84,281,1620716400"; d="scan'208";a="213070255" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 Jul 2021 23:12:49 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.84,281,1620716400"; d="scan'208";a="465345165" Received: from allen-box.sh.intel.com (HELO [10.239.159.118]) ([10.239.159.118]) by orsmga008.jf.intel.com with ESMTP; 29 Jul 2021 23:12:46 -0700 Cc: baolu.lu@linux.intel.com, iommu@lists.linux-foundation.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, suravee.suthikulpanit@amd.com, john.garry@huawei.com, dianders@chromium.org Subject: Re: [PATCH v2 19/24] iommu: Expose DMA domain strictness via sysfs To: Robin Murphy , joro@8bytes.org, will@kernel.org References: From: Lu Baolu Message-ID: Date: Fri, 30 Jul 2021 14:10:28 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210729_231249_550968_84254FBD X-CRM114-Status: GOOD ( 23.17 ) 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: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 7/28/21 11:58 PM, Robin Murphy wrote: > 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 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 > Reviewed-by: Lu Baolu Best regards, baolu _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel