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 X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1886EC2D0DE for ; Wed, 1 Jan 2020 05:28:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E325E206DA for ; Wed, 1 Jan 2020 05:28:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725943AbgAAF2W (ORCPT ); Wed, 1 Jan 2020 00:28:22 -0500 Received: from mga01.intel.com ([192.55.52.88]:55757 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725765AbgAAF2W (ORCPT ); Wed, 1 Jan 2020 00:28:22 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by fmsmga101.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 31 Dec 2019 21:28:21 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.69,382,1571727600"; d="scan'208";a="244319507" Received: from allen-box.sh.intel.com ([10.239.159.136]) by fmsmga004.fm.intel.com with ESMTP; 31 Dec 2019 21:28:19 -0800 From: Lu Baolu To: Joerg Roedel , Greg Kroah-Hartman , Bjorn Helgaas Cc: ashok.raj@intel.com, jacob.jun.pan@intel.com, kevin.tian@intel.com, Christoph Hellwig , Robin Murphy , iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, Lu Baolu Subject: [RFC PATCH 0/4] iommu: Per-group default domain type Date: Wed, 1 Jan 2020 13:26:44 +0800 Message-Id: <20200101052648.14295-1-baolu.lu@linux.intel.com> X-Mailer: git-send-email 2.17.1 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org An IOMMU group represents the smallest set of devices that are considered to be isolated. All devices belonging to an IOMMU group share a default domain for DMA APIs. There are two types of default domain: IOMMU_DOMAIN_DMA and IOMMU_DOMAIN_IDENTITY. The former means IOMMU translation, while the latter means IOMMU by-pass. Currently, the default domain type for the IOMMU groups is determined globally. All IOMMU groups use a single default domain type. The global default domain type can be adjusted by kernel build configuration or kernel parameters. More and more users are looking forward to a fine grained default domain type. For example, with the global default domain type set to translation, the OEM verndors or end users might want some trusted and fast-speed devices to bypass IOMMU for performance gains. On the other hand, with global default domain type set to by-pass, some devices with limited system memory addressing capability might want IOMMU translation to remove the bounce buffer overhead. This series proposes per-group default domain type to meet these demands. It adds a per-device iommu_passthrough attribute. By setting this attribute, end users or device vendors are able to tell the IOMMU subsystem that this device is willing to use a default domain of IOMMU_DOMAIN_IDENTITY. The IOMMU device probe procedure is reformed to pre-allocate groups for all devices on a specific bus before adding the devices into the groups. This enables the IOMMU device probe precedure to determine a per-group default domain type before allocating IOMMU domains and attaching them to devices. Please help to review it. Your comments and suggestions are appricated. Best regards, baolu Lu Baolu (4): driver core: Add iommu_passthrough to struct device PCI: Add "pci=iommu_passthrough=" parameter for iommu passthrough iommu: Preallocate iommu group when probing devices iommu: Determine default domain type before allocating domain .../admin-guide/kernel-parameters.txt | 5 + drivers/iommu/iommu.c | 127 ++++++++++++++---- drivers/pci/pci.c | 34 +++++ drivers/pci/pci.h | 1 + drivers/pci/probe.c | 2 + include/linux/device.h | 3 + 6 files changed, 143 insertions(+), 29 deletions(-) -- 2.17.1