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 1BC9CC433FE for ; Sun, 20 Mar 2022 06:29:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244815AbiCTGak (ORCPT ); Sun, 20 Mar 2022 02:30:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54924 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244814AbiCTGak (ORCPT ); Sun, 20 Mar 2022 02:30:40 -0400 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 238BDF1EA5 for ; Sat, 19 Mar 2022 23:29:17 -0700 (PDT) Received: by mail-yb1-xb4a.google.com with SMTP id h8-20020a25e208000000b00628c0565607so9970948ybe.0 for ; Sat, 19 Mar 2022 23:29:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=ASJzKtjYfW3z8f/kiOdf3O3IhYj+R3xbLBVIICLaL3k=; b=dPFkW/Ck2UL5AoOdA6Cz0rPjNvn8yK05uE0Xm2HL/viXm1ySX1TLtgDnqRKai9VyMl KLy4K5nYOqrleAfGBOFi14Jz8snJOM/Ma3lE5CQaWYaq9GNDs8Tbwqgb9al+0Frlcho0 cXAEGoW8VtU11wcxOJOnzwgXAgwWe6avL9HI6MybXN92SKK6Mn2o330K1OzbD3AE5f4c AX0t6SUjhSdCulmD3jO0nRMVEwMLRkEAja9VO8AX8kQnJDyncnJdrdCeFcDee0PM4inx 5bq5duGStWNWRNbLTMkjtH5WgvXivj37aFUbhbREceZOmLwQ2PCavmihJR2SuBIsN2yH CivA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=ASJzKtjYfW3z8f/kiOdf3O3IhYj+R3xbLBVIICLaL3k=; b=ZeHwepgVq3SizbqN4pV9yM/RJ99WaT9/F4UR6WifC1hLPe7h/7lX7hx7tnv1esL2Pj l7ltTfP3OmJodeTAxZycvMoiPJ9c/6igcK0jBskUPDR18+g0eTE0ytunNERog7Mf0di5 3Kwc08lgmedxKe/cNcvUQZXYtspns8R3Yu+6FmIHwfXky7IdpNJaRNExBInihRAintxq SP2aCqtfQOskKzgfF81Ti4mOBL4g4e5hrAK3QSe+xgWBVzZ8sCL5tj1j5lv5AK4TBDfS WtmF/N751cYWkzF2rSUo45dcy1qrE2VrM3+eRzETxoSFL112VTgC8hs7NqU0RxuTCbvb 4phw== X-Gm-Message-State: AOAM531LPFrHG8YwwYs5iYWCyxcBYaJRsdeloLGqkBJS9eGHJQx5IV1H OlOj24MJtpB7O8qFfjjdpH7AxzcwRhUT X-Google-Smtp-Source: ABdhPJyA1/PLVkOcQRO7zP5IrnCWC5GLuOxnX8km0260X51BYH8R29UtxaOINOdqUREPgrXHVEXZVZqiVanY X-Received: from rajat2.mtv.corp.google.com ([2620:15c:202:201:5445:bc31:4f4a:d610]) (user=rajatja job=sendgmr) by 2002:a25:c884:0:b0:633:7961:8a06 with SMTP id y126-20020a25c884000000b0063379618a06mr17596271ybf.38.1647757756226; Sat, 19 Mar 2022 23:29:16 -0700 (PDT) Date: Sat, 19 Mar 2022 23:29:06 -0700 In-Reply-To: <20220320062907.3272903-1-rajatja@google.com> Message-Id: <20220320062907.3272903-2-rajatja@google.com> Mime-Version: 1.0 References: <20220320062907.3272903-1-rajatja@google.com> X-Mailer: git-send-email 2.35.1.894.gb6a874cedc-goog Subject: [PATCH v4 2/2] 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 Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-acpi@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 --- v4: * Add the GUID. * Use the (now) renamed property - pci_dev->poses_dma_risk) * 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..5360f1af2ed3 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->poses_dma_risk = 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); -- 2.35.1.894.gb6a874cedc-goog