From patchwork Tue Apr 26 00:06:39 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Rajat Jain X-Patchwork-Id: 12826369 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 98F7EC433F5 for ; Tue, 26 Apr 2022 00:06:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239146AbiDZAJv (ORCPT ); Mon, 25 Apr 2022 20:09:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58538 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229658AbiDZAJu (ORCPT ); Mon, 25 Apr 2022 20:09:50 -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 D4F73120111 for ; Mon, 25 Apr 2022 17:06:44 -0700 (PDT) Received: by mail-yb1-xb49.google.com with SMTP id h14-20020a25e20e000000b006484e4a1da2so4429745ybe.9 for ; Mon, 25 Apr 2022 17:06:44 -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=EQ6VT6w46Hd44XRTan9TInx0ubvgoNtxDCqLgonw/Fw=; b=HS1HO9FzmdSJFLMep5JjzcdD/vAauAAiJdJtzVrco1UZk50LeqYCzwhWCfRJZ34zuo qofqkRZyy6+RFdFh2w+QDW8VSe7d6xxNp46ta/i+iF8YOjRw3+5tLbnRtaro28Cio8o4 OiNAeSDzHohgt4vbhCl/9Wvc9F6y3USITzJ10+JX+o97t3jdebP1nHALnKme07MYlKGU mxH/cmQgkqRAOh5TyDU0LaZ+kzTDPONTBv2KsgkeszUMtpbaBxIlgTjQx1ZHJGgr9rAO X8d6uZP7cZOeMc6TODikbj71Y+Li4qUszasbi90W6haTph6MsBXtG6XPJ0xdp8YxPd40 2tBw== 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=EQ6VT6w46Hd44XRTan9TInx0ubvgoNtxDCqLgonw/Fw=; b=fwwGtEdQ8voBrAw5vLprmnxoqakI7B0ec3K+cqeUcPt0BwpiT7zGfd0HzYAHbfASRx nFrSQxVpZV+ujPVPsYevB70QbujVkvwwyUkzkTqzrkXRg7hnpp6BKyEBKyPvRBAPe4wX 0KcTQhvVGSxSR4ISv7t7ky6oWgzPvGGlDoQTrG5mb7y1PVHJ1ixjK5wdgX8+vKjpj8TD QUsiHdmBXkZ+7t71eikJqFbToJQsEyg5pUoko0db+BpEp+IqUvqImIVSJizVTvAjxjRE vKTkFlG+YYp771EJa77hK1RenRJFk3r4kAngYaHXdjsRepsY6NPkXe/Q/1TArvSyXY8w vrew== X-Gm-Message-State: AOAM532X3fkMrP71LzfEsxWtxhWflgLZzkuMDt5kxJaTq68CE4KAWC6B d8ai+A/vEPlb6KjXVPAHCBR3z+ut4njv X-Google-Smtp-Source: ABdhPJwNNzWNR0miZ2gObmHApAL+Qq+RPW++GHIubAxH7gus9hz33wGevQAaQAJC9bdTGWNEfprWQMSD7v1q X-Received: from rajat2.mtv.corp.google.com ([2620:15c:202:201:9590:6ed7:be38:9068]) (user=rajatja job=sendgmr) by 2002:a25:f30f:0:b0:648:6d75:614 with SMTP id c15-20020a25f30f000000b006486d750614mr6652624ybs.558.1650931604103; Mon, 25 Apr 2022 17:06:44 -0700 (PDT) Date: Mon, 25 Apr 2022 17:06:39 -0700 Message-Id: <20220426000640.3581446-1-rajatja@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.36.0.rc2.479.g8af0fa9b8e-goog Subject: [PATCH v6 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" Precedence: bulk List-ID: X-Mailing-List: linux-pci@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 --- 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 | 21 +++++++++++++++++++++ 2 files changed, 24 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..d7c6ba48486f 100644 --- a/drivers/pci/pci-acpi.c +++ b/drivers/pci/pci-acpi.c @@ -1369,12 +1369,33 @@ 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 also used by Microsoft Windows for same purpose, + * (to implement DMA protection from a device, using the IOMMU). + */ + 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);