From patchwork Fri Mar 25 18:46:08 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Rajat Jain X-Patchwork-Id: 12791982 X-Patchwork-Delegate: bhelgaas@google.com 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 C0A7BC4332F for ; Fri, 25 Mar 2022 19:39:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230457AbiCYTkc (ORCPT ); Fri, 25 Mar 2022 15:40:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44420 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233350AbiCYTjw (ORCPT ); Fri, 25 Mar 2022 15:39:52 -0400 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5509E1546A5 for ; Fri, 25 Mar 2022 12:12:20 -0700 (PDT) Received: by mail-yb1-xb49.google.com with SMTP id h8-20020a25e208000000b00628c0565607so6807581ybe.0 for ; Fri, 25 Mar 2022 12:12:20 -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=woMjFLNUegNjbJ51x62lvW6UbmQA+Ba7zyUjvkY6YYA=; b=pPUMCEvf8BZ62Y/c+W1qNInLop6JGyWd784jOQMkj1CbDHqg6py/a0QUTHIl90KdK9 w8p+a0V9OwXTGRp2ndKsQIWc5a+N8W0cnnGZFdPvIxrlF1S6agDjEDnrq+kop7VArS9W RbYNWRUOGzcuxrBV4L2CC5m9He2upt/Ljn2rs9gmG3kXrsXyBQMYXRw3Gbsg1t4Arnqw Vz5BauwAV3zM0pm0GHPutIyIuVDPFsGPQzM4SkLsQISvm66TNi9ybfRXySbc8zm/ozK8 dVwdJktR7GmW3rsxUBUyM3bSBrBGyKaXWu9kydtN+Kk/btVZUC8+M9kY4J9l0j+/DcQR l9Qg== 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=woMjFLNUegNjbJ51x62lvW6UbmQA+Ba7zyUjvkY6YYA=; b=bsprFepp01fowvXqGyBOZ+ex0KySQ6VhygmA7xjY+e3oGG1KbkkEvT/khL0pNz/KBP bWgeJcwmISBYsbavBlQsmyRDihmMHKpIdup0pHbqIUGm3R6axnEpIFIGEmGDW3aM9lsq 70MKaIC1AizvhBFuvptIGulJePmETfZYDZdos8IYu+Z+q889Co+Cr7ZXycYj+vK5AHMo 3GphxBooUUV0wxJsumtsFm674gzUgIH8Hky/4LUhuJeR4NFIKp5LQujHin8OhfGA7aDN yduTzf4luvLHCKvbCQDdjctJbYiaHCTnoGTRAcaP5j789D1n4naBdLFMEC81rXc3Wfis 8aPw== X-Gm-Message-State: AOAM531Wi/Iauj5ldwyxLEcY0thKjcudQGc/MOptFq22EggGTqFTtmVM g5W6Fqu6zM9rx/qu1YrYyps8WpvWQfY0 X-Google-Smtp-Source: ABdhPJyRS7LP7fvCaSt0TldDrztqH9QfayLTVY7BMeLHgtTzqTb9UkZpPGUKvtovyGUbBIdo731RsDJISrP1 X-Received: from rajat2.mtv.corp.google.com ([2620:15c:202:201:4cfc:6eaf:38d8:46d6]) (user=rajatja job=sendgmr) by 2002:a81:94d:0:b0:2e5:b91a:195b with SMTP id 74-20020a81094d000000b002e5b91a195bmr12106133ywj.44.1648233973993; Fri, 25 Mar 2022 11:46:13 -0700 (PDT) Date: Fri, 25 Mar 2022 11:46:08 -0700 Message-Id: <20220325184609.4059963-1-rajatja@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.35.1.1021.g381101b075-goog Subject: [PATCH v5 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 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org The "DmaProperty" is supported and documented by Microsoft here: https://docs.microsoft.com/en-us/windows-hardware/drivers/pci/dsd-for-pcie-root-ports They use this property for DMA protection: https://docs.microsoft.com/en-us/windows/security/information-protection/kernel-dma-protection-for-thunderbolt Support the "DmaProperty" with the same semantics. This is useful for internal PCI devices that do not hang off a PCIe rootport, but offer an attack surface for DMA attacks (e.g. internal network devices). Signed-off-by: Rajat Jain Reviewed-by: Mika Westerberg Acked-by: Rafael J. Wysocki --- 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 | 16 ++++++++++++++++ 2 files changed, 19 insertions(+) diff --git a/drivers/acpi/property.c b/drivers/acpi/property.c index d0986bda2964..20603cacc28d 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 1f15ab7eabf8..378e05096c52 100644 --- a/drivers/pci/pci-acpi.c +++ b/drivers/pci/pci-acpi.c @@ -1350,12 +1350,28 @@ static void pci_acpi_set_external_facing(struct pci_dev *dev) dev->external_facing = 1; } +static void pci_acpi_check_for_dma_protection(struct pci_dev *dev) +{ + u8 val; + + /* + * Property also used by Microsoft Windows for same purpose, + * (to implement DMA protection from a device, using the IOMMU). + */ + if (device_property_read_u8(&dev->dev, "DmaProperty", &val)) + return; + + if (val) + dev->untrusted = 1; +} + 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_acpi_check_for_dma_protection(pci_dev); pci_acpi_add_edr_notifier(pci_dev); pci_acpi_add_pm_notifier(adev, pci_dev);