From patchwork Fri Sep 14 14:30:22 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Robin Murphy X-Patchwork-Id: 10600837 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 40E7F14BD for ; Fri, 14 Sep 2018 14:34:02 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 20FDA2B7D9 for ; Fri, 14 Sep 2018 14:34:02 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 14CBD2B7FB; Fri, 14 Sep 2018 14:34:02 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 546532B7D9 for ; Fri, 14 Sep 2018 14:34:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=pjigAcKi+vL6ul8B/c8lQsQql9q7K9aOZ2uNUtk8S4Y=; b=RGLnW8YxElqTr+ FdcnnwTV7GuOC6FcoEFDBJ7xSvl+UvHjv2TLkx2uavsaGDjMwXmGC8CCTuw0bDn19jmvlaQ6Fqk3o 432QZkVxNTyqkelJ2nzKMqGjym29XbjqZHn6EUQ9CUDfQhTEFBDATSylkhcOp59gOx5mnAPdncEHz 9YszwKyJtXTS5x7YV6X3YuO+31P/jMj5e8IwdUDzYN8v3tuRRss09LPqQwvFiDVu3c36cCeUzZNQM 7ONV6Z/OTiMS80ag0XvNt4QIOaed/JxpDKEC9Q1IAgfbPliE1bIu1vyMIQgxJmDoIE8MZBbw3cmAe lOk7VTro09i/mDuakdJg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1g0pAP-0005Dc-RM; Fri, 14 Sep 2018 14:33:53 +0000 Received: from foss.arm.com ([217.140.101.70]) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1g0p7J-0003m9-7f for linux-arm-kernel@lists.infradead.org; Fri, 14 Sep 2018 14:30:45 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 1EA8E15BF; Fri, 14 Sep 2018 07:30:41 -0700 (PDT) Received: from e110467-lin.cambridge.arm.com (e110467-lin.emea.arm.com [10.4.12.131]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 549373F575; Fri, 14 Sep 2018 07:30:39 -0700 (PDT) From: Robin Murphy To: joro@8bytes.org, will.deacon@arm.com, thunder.leizhen@huawei.com, iommu@lists.linux-foundation.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH v7 4/6] iommu: Add bootup option "iommu.non_strict" Date: Fri, 14 Sep 2018 15:30:22 +0100 Message-Id: <41f81c46348db4acd9a542184f10e7ca24f6c219.1536935328.git.robin.murphy@arm.com> X-Mailer: git-send-email 2.19.0.dirty In-Reply-To: References: MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20180914_073041_300951_C2CBEE63 X-CRM114-Status: GOOD ( 17.78 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: john.garry@huawei.com, linuxarm@huawei.com, huawei.libin@huawei.com, guohanjun@huawei.com Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP From: Zhen Lei Add a bootup option to make the system manager can choose which mode to be used. The default mode is strict. Signed-off-by: Zhen Lei [rm: move handling out of SMMUv3 driver] Signed-off-by: Robin Murphy --- .../admin-guide/kernel-parameters.txt | 13 ++++++++++ drivers/iommu/iommu.c | 26 +++++++++++++++++++ 2 files changed, 39 insertions(+) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 9871e649ffef..406b91759b62 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1749,6 +1749,19 @@ nobypass [PPC/POWERNV] Disable IOMMU bypass, using IOMMU for PCI devices. + iommu.non_strict= [ARM64] + Format: { "0" | "1" } + 0 - strict mode, default. + Release IOVAs after the related TLBs are invalid + completely. + 1 - non-strict mode. + Put off TLBs invalidation and release memory first. + It's good for scatter-gather performance but lacks + full isolation, an untrusted device can access the + reused memory because the TLBs may still valid. + Please take full consideration before choosing this + mode. Note that, VFIO will always use strict mode. + iommu.passthrough= [ARM64] Configure DMA to bypass the IOMMU by default. Format: { "0" | "1" } diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 8c15c5980299..2cabd0c0a4f3 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -41,6 +41,7 @@ static unsigned int iommu_def_domain_type = IOMMU_DOMAIN_IDENTITY; #else static unsigned int iommu_def_domain_type = IOMMU_DOMAIN_DMA; #endif +static bool iommu_dma_non_strict __read_mostly; struct iommu_callback_data { const struct iommu_ops *ops; @@ -131,6 +132,24 @@ static int __init iommu_set_def_domain_type(char *str) } early_param("iommu.passthrough", iommu_set_def_domain_type); +static int __init iommu_dma_setup(char *str) +{ + int ret; + + ret = kstrtobool(str, &iommu_dma_non_strict); + if (ret) + return ret; + + if (iommu_dma_non_strict) { + pr_warn("WARNING: iommu non-strict mode is chosen.\n" + "It's good for scatter-gather performance but lacks full isolation\n"); + add_taint(TAINT_WARN, LOCKDEP_STILL_OK); + } + + return 0; +} +early_param("iommu.non_strict", iommu_dma_setup); + static ssize_t iommu_group_attr_show(struct kobject *kobj, struct attribute *__attr, char *buf) { @@ -1072,6 +1091,13 @@ struct iommu_group *iommu_group_get_for_dev(struct device *dev) group->default_domain = dom; if (!group->domain) group->domain = dom; + + if (dom && iommu_dma_non_strict) { + int attr = 1; + iommu_domain_set_attr(dom, + DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE, + &attr); + } } ret = iommu_group_add_device(group, dev);