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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7D3E7C433EF for ; Tue, 26 Apr 2022 17:21:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348847AbiDZRYj (ORCPT ); Tue, 26 Apr 2022 13:24:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38208 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346080AbiDZRYS (ORCPT ); Tue, 26 Apr 2022 13:24:18 -0400 Received: from mail-yw1-x114a.google.com (mail-yw1-x114a.google.com [IPv6:2607:f8b0:4864:20::114a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4380A3AA5F for ; Tue, 26 Apr 2022 10:21:10 -0700 (PDT) Received: by mail-yw1-x114a.google.com with SMTP id 00721157ae682-2eb2bc9018aso161331907b3.18 for ; Tue, 26 Apr 2022 10:21:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:message-id:mime-version:subject:from:to:cc; bh=K4cYGbh8rteU7qjrkcHqWVz1gvqfkrcrzyhG72fd0AA=; b=E9wtd87DRD48eM33gm49dXZAuiy90o56mu8zO7VUJbEb2zsXsjqgtolPYWCvofqG4u 1O1IsLQkG+xSduUpGX8min2UXIAtDIAtXFUF6lE3kZan3d0wm6003yclVrY0HU/QCFq3 Qzk4Vm1l5PbUtJyxSQvalZTNS8Yu4LZyIrsediKkJM2B3WYNTnuuM6kwpTh3RGjE5LSw TiSdmY4BPd/kJ63/LXh93F5GhHxsveoWeRxqazIQVC4553hBedfxSiBjCsFo1jBzzCPP 8VuAtASAUq8RcINKQsGXGwocf9VGGn0JiQaJbyJUzDFElq22mc57sAX3UYxHzxf/9VUP 7eZA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=K4cYGbh8rteU7qjrkcHqWVz1gvqfkrcrzyhG72fd0AA=; b=06vJN7GuBCrXRCNMvSh13XvlVkMJ/7Q4+JqPYNlxOqwiKGWxCc4pwmsL59kTIfOusO vVpNsMhICb9QkE9tu2kV5fNew3wA7b41iqLH8IAFf5San0/VNHuteCDVejGT0ALiQOU2 gHrctmA0JkgTe6GrU9LIJEQWyFzudlI1NRkLEJl7UidH8zHWC4vz3OzDy5FNV4aWwn6w iRDuADSWsXEHL4hlU5rOIxljyMT99DLy5szo72UV8NjrTJkojw5K6UEhsMZSRg/YP9Yq 3y2M4EdFRC5WEGTMU7x3XzxrMfZ7zMXV8n1c6jh0SqsupVaT2ZPk9iGG2l/33U6Rc6td XipA== X-Gm-Message-State: AOAM531IVzaz5vEmIL8FpFG3ck3FlHI8mnhM4w3jWNYtWPhWJB+fNsqm WeMNtDVGM/Qxzu2FxjAGC2G6OPHAEGHs X-Google-Smtp-Source: ABdhPJzYSi5B3Wy/sEmQfwOrq+K0Yc+a58hKNTB54O8pj+BeIlXY7fRBF1kOrEQw8bcB/yl4ql5Vf+Va2No7 X-Received: from rajat2.mtv.corp.google.com ([2620:15c:202:201:ce74:273e:a60f:b750]) (user=rajatja job=sendgmr) by 2002:a25:4243:0:b0:645:7c15:c34b with SMTP id p64-20020a254243000000b006457c15c34bmr22669071yba.46.1650993669427; Tue, 26 Apr 2022 10:21:09 -0700 (PDT) Date: Tue, 26 Apr 2022 10:21:04 -0700 Message-Id: <20220426172105.3663170-1-rajatja@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.36.0.rc2.479.g8af0fa9b8e-goog Subject: [PATCH v7 1/2] PCI/ACPI: Support Microsoft's "DmaProperty" From: Rajat Jain To: "Rafael J. Wysocki" , Len Brown , linux-pci@vger.kernel.org, Mika Westerberg , Greg Kroah-Hartman , Bjorn Helgaas , Bjorn Helgaas , ACPI Devel Maling List , Linux Kernel Mailing List , Rajat Jain , Dmitry Torokhov , Jesse Barnes , Jean-Philippe Brucker , Pavel Machek , "Oliver O'Halloran" , Joerg Roedel , Will Deacon , David Woodhouse , Lu Baolu , iommu@lists.linux-foundation.org Cc: Rajat Jain , "Rafael J . Wysocki" Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The "DmaProperty" is supported and currently documented and used by Microsoft [link 1 below], to flag internal PCIe root ports that need DMA protection [link 2 below]. We have discussed with them and reached a common understanding that they shall change their MSDN documentation to say that the same property can be used to protect any PCI device, and not just internal PCIe root ports (since there is no point introducing yet another property for arbitrary PCI devices). This helps with security from internal devices that offer an attack surface for DMA attacks (e.g. internal network devices). Support DmaProperty to mark DMA from a PCI device as untrusted. Link: [1] https://docs.microsoft.com/en-us/windows-hardware/drivers/pci/dsd-for-pcie-root-ports#identifying-internal-pcie-ports-accessible-to-users-and-requiring-dma-protection Link: [2] https://docs.microsoft.com/en-us/windows/security/information-protection/kernel-dma-protection-for-thunderbolt Signed-off-by: Rajat Jain Reviewed-by: Mika Westerberg Acked-by: Rafael J. Wysocki --- v7: * Update the comment, based on feedback. v6: * Take care of Bjorn's comments: - Update the commit log - Rename to pci_dev_has_dma_property() - Use acpi_dev_get_property() v5: * Reorder the patches in the series v4: * Add the GUID. * Update the comment and commitlog. v3: * Use Microsoft's documented property "DmaProperty" * Resctrict to ACPI only drivers/acpi/property.c | 3 +++ drivers/pci/pci-acpi.c | 22 ++++++++++++++++++++++ 2 files changed, 25 insertions(+) diff --git a/drivers/acpi/property.c b/drivers/acpi/property.c index 12bbfe833609..bafe35c301ac 100644 --- a/drivers/acpi/property.c +++ b/drivers/acpi/property.c @@ -48,6 +48,9 @@ static const guid_t prp_guids[] = { /* Storage device needs D3 GUID: 5025030f-842f-4ab4-a561-99a5189762d0 */ GUID_INIT(0x5025030f, 0x842f, 0x4ab4, 0xa5, 0x61, 0x99, 0xa5, 0x18, 0x97, 0x62, 0xd0), + /* DmaProperty for PCI devices GUID: 70d24161-6dd5-4c9e-8070-705531292865 */ + GUID_INIT(0x70d24161, 0x6dd5, 0x4c9e, + 0x80, 0x70, 0x70, 0x55, 0x31, 0x29, 0x28, 0x65), }; /* ACPI _DSD data subnodes GUID: dbb8e3e6-5886-4ba6-8795-1319f52a966b */ diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c index 3ae435beaf0a..8cb4725d41fa 100644 --- a/drivers/pci/pci-acpi.c +++ b/drivers/pci/pci-acpi.c @@ -1369,12 +1369,34 @@ static void pci_acpi_set_external_facing(struct pci_dev *dev) dev->external_facing = 1; } +static int pci_dev_has_dma_property(struct pci_dev *dev) +{ + struct acpi_device *adev; + const union acpi_object *obj; + + adev = ACPI_COMPANION(&dev->dev); + if (!adev) + return 0; + + /* + * Property used by Microsoft Windows to enforce IOMMU DMA + * protection from any device, that the system may not fully trust; + * we'll honour it the same way. + */ + if (!acpi_dev_get_property(adev, "DmaProperty", ACPI_TYPE_INTEGER, + &obj) && obj->integer.value == 1) + return 1; + + return 0; +} + void pci_acpi_setup(struct device *dev, struct acpi_device *adev) { struct pci_dev *pci_dev = to_pci_dev(dev); pci_acpi_optimize_delay(pci_dev, adev->handle); pci_acpi_set_external_facing(pci_dev); + pci_dev->untrusted |= pci_dev_has_dma_property(pci_dev); pci_acpi_add_edr_notifier(pci_dev); pci_acpi_add_pm_notifier(adev, pci_dev); -- 2.36.0.rc2.479.g8af0fa9b8e-goog