From patchwork Mon Nov 26 11:15:25 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mika Westerberg X-Patchwork-Id: 10698003 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 A2414109C for ; Mon, 26 Nov 2018 11:15:54 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9098A28935 for ; Mon, 26 Nov 2018 11:15:54 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 83D3C2893E; Mon, 26 Nov 2018 11:15:54 +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=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id DFA3928935 for ; Mon, 26 Nov 2018 11:15:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730349AbeKZWJW (ORCPT ); Mon, 26 Nov 2018 17:09:22 -0500 Received: from mga06.intel.com ([134.134.136.31]:13922 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726231AbeKZWJU (ORCPT ); Mon, 26 Nov 2018 17:09:20 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga006.jf.intel.com ([10.7.209.51]) by orsmga104.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 26 Nov 2018 03:15:33 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.56,281,1539673200"; d="scan'208";a="94071696" Received: from black.fi.intel.com ([10.237.72.28]) by orsmga006.jf.intel.com with ESMTP; 26 Nov 2018 03:15:27 -0800 Received: by black.fi.intel.com (Postfix, from userid 1001) id F0B13546; Mon, 26 Nov 2018 13:15:26 +0200 (EET) From: Mika Westerberg To: iommu@lists.linux-foundation.org Cc: Joerg Roedel , David Woodhouse , Lu Baolu , Ashok Raj , Bjorn Helgaas , "Rafael J. Wysocki" , Jacob jun Pan , Andreas Noever , Michael Jamet , Yehezkel Bernat , Lukas Wunner , Christian Kellner , Mario.Limonciello@dell.com, Anthony Wong , Lorenzo Pieralisi , Christoph Hellwig , Alex Williamson , Mika Westerberg , linux-acpi@vger.kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 3/4] iommu/vt-d: Do not enable ATS for untrusted devices Date: Mon, 26 Nov 2018 14:15:25 +0300 Message-Id: <20181126111526.56340-4-mika.westerberg@linux.intel.com> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181126111526.56340-1-mika.westerberg@linux.intel.com> References: <20181126111526.56340-1-mika.westerberg@linux.intel.com> MIME-Version: 1.0 Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Currently Linux automatically enables ATS (Address Translation Service) for any device that supports it (and IOMMU is turned on). ATS is used to accelerate DMA access as the device can cache translations locally so there is no need to do full translation on IOMMU side. However, as pointed out in [1] ATS can be used to bypass IOMMU based security completely by simply sending PCIe read/write transaction with AT (Address Translation) field set to "translated". To mitigate this modify the Intel IOMMU code so that it does not enable ATS for any device that is marked as being untrusted. In case this turns out to cause performance issues we may selectively allow ATS based on user decision but currently use big hammer and disable it completely to be on the safe side. [1] https://www.repository.cam.ac.uk/handle/1810/274352 Signed-off-by: Mika Westerberg Reviewed-by: Ashok Raj Reviewed-by: Joerg Roedel Acked-by: Joerg Roedel --- drivers/iommu/intel-iommu.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index 76e135ee9b19..c964315deddd 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -1473,7 +1473,8 @@ static void iommu_enable_dev_iotlb(struct device_domain_info *info) if (info->pri_supported && !pci_reset_pri(pdev) && !pci_enable_pri(pdev, 32)) info->pri_enabled = 1; #endif - if (info->ats_supported && !pci_enable_ats(pdev, VTD_PAGE_SHIFT)) { + if (!pdev->is_untrusted && info->ats_supported && + !pci_enable_ats(pdev, VTD_PAGE_SHIFT)) { info->ats_enabled = 1; domain_update_iotlb(info->domain); info->ats_qdep = pci_ats_queue_depth(pdev);