Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Received-SPF: Pass (protection.outlook.com: domain of amd.com designates
 165.204.84.17 as permitted sender) receiver=protection.outlook.com;
 client-ip=165.204.84.17; helo=SATLEXMB04.amd.com; pr=C
From:   Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
To:     <linux-kernel@vger.kernel.org>, <iommu@lists.linux-foundation.org>
CC:     <joro@8bytes.org>, <robin.murphy@arm.com>, <ashish.kalra@amd.com>,
        <vasant.hegde@amd.com>, <thomas.lendacky@amd.com>,
        Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Subject: [PATCH v3 0/7] iommu/amd: Enforce IOMMU restrictions for SNP-enabled system
Date:   Wed, 22 Jun 2022 12:11:24 -0500
Message-ID: <20220622171131.11870-1-suravee.suthikulpanit@amd.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Content-Type: text/plain
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 22 Jun 2022 17:12:33.7365
 (UTC)
X-MS-Exchange-CrossTenant-Network-Message-Id: 0bb67e03-38bc-4c43-d591-08da547265ea
X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d
X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=3dd8961f-e488-4e60-8e11-a82d994e183d;Ip=[165.204.84.17];Helo=[SATLEXMB04.amd.com]
X-MS-Exchange-CrossTenant-AuthSource: CO1NAM11FT005.eop-nam11.prod.protection.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Anonymous
X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem
X-MS-Exchange-Transport-CrossTenantHeadersStamped: BN8PR12MB3570
X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED,
        DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE,
        RCVD_IN_MSPIKE_H2,SPF_HELO_PASS,SPF_PASS,T_SCC_BODY_TEXT_LINE
        autolearn=ham autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
        lindbergh.monkeyblade.net
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

SNP-enabled system requires IOMMU v1 page table to be configured with
non-zero DTE[Mode] for DMA-capable devices. This effects a number of
usecases such as IOMMU pass-through mode and AMD IOMMUv2 APIs for
binding/unbinding pasid.

The series introduce a global variable to check SNP-enabled state
during driver initialization, and use it to enforce the SNP restrictions
during runtime.

Also, for non-DMA-capable devices such as IOAPIC, the recommendation
is to set DTE[TV] and DTE[Mode] to zero on SNP-enabled system.
Therefore, additinal checks is added before setting DTE[TV].

Testing:
  - Tested booting and verify dmesg.
  - Tested booting with iommu=pt
  - Tested loading amd_iommu_v2 driver
  - Tested changing the iommu domain at runtime
  - Tested booting SEV/SNP-enabled guest
  - Tested when CONFIG_AMD_MEM_ENCRYPT is not set

Pre-requisite:
  - [PATCH v3 00/35] iommu/amd: Add multiple PCI segments support
    https://lore.kernel.org/linux-iommu/20220511072141.15485-29-vasant.hegde@amd.com/T/

Chanages from V2:
(https://lists.linuxfoundation.org/pipermail/iommu/2022-June/066392.html)
  - Patch 4:
     * Update pr_err message to report SNP not supported.
     * Remove export GPL.
     * Remove function stub when CONFIG_AMD_MEM_ENCRYPT is not set.
  - Patch 6: Change to WARN_ONCE.

Best Regards,
Suravee

Brijesh Singh (1):
  iommu/amd: Introduce function to check and enable SNP

Suravee Suthikulpanit (6):
  iommu/amd: Warn when found inconsistency EFR mask
  iommu/amd: Process all IVHDs before enabling IOMMU features
  iommu/amd: Introduce an iommu variable for tracking SNP support status
  iommu/amd: Set translation valid bit only when IO page tables are in
    use
  iommu/amd: Do not support IOMMU_DOMAIN_IDENTITY after SNP is enabled
  iommu/amd: Do not support IOMMUv2 APIs when SNP is enabled

 drivers/iommu/amd/amd_iommu_types.h |   5 ++
 drivers/iommu/amd/init.c            | 109 +++++++++++++++++++++++-----
 drivers/iommu/amd/iommu.c           |  27 ++++++-
 include/linux/amd-iommu.h           |   4 +
 4 files changed, 123 insertions(+), 22 deletions(-)

-- 
2.32.0