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;
Message-ID: <66cbb44b-290d-5a00-e6e3-4da586821e9e@amd.com>
Date:   Thu, 28 Apr 2022 13:04:21 +0530
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101
 Thunderbird/91.8.1
Subject: Re: [PATCH] iommu/amd: Set translation valid bit only when IO page
 tables are in used
Content-Language: en-US
To:     Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>,
        linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org
Cc:     jon.grimm@amd.com
References: <20220420112920.18091-1-suravee.suthikulpanit@amd.com>
From:   Vasant Hegde <vasant.hegde@amd.com>
In-Reply-To: <20220420112920.18091-1-suravee.suthikulpanit@amd.com>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?dmg0M2wvcGlzRjdsWDlWWHFReDFiUzVtaDZoWWwzaERDeVE3aklzU0RXTm1O?=
 =?utf-8?B?c2lENUcwUno3aG5kNHBtbGg0U2lMR0l5MklXcGIrdGRyaWprWC9CekQzV0pK?=
 =?utf-8?B?VW45eVlrSGx6ZldiN2IxR2p1bm9ONjFLVG9HMlpaT0M4NDd2MjMrVEtlcjRO?=
 =?utf-8?B?NVBsc1kzUUtpYklMaThjMWxGYkM5MGRDYWZvbm5VamJhR2tOWUJLYStPVVEx?=
 =?utf-8?B?bnRFdWpzU3Y5VGx4aTJtMXNqaG80azBuYXRobzRweW1mL1dETGVlVU9QZTlj?=
 =?utf-8?B?ZmR0Z3YyY2J2ZzNkbjQvdTljWHg0TnJlblV2YXRtRGQvN2diamw4bU1rcEF6?=
 =?utf-8?B?N1ZIYmEvSjlqV1FYYXZIelFNVjZZVjFxR3E4dzREMVBzaUt1SFowY0lRNExw?=
 =?utf-8?B?RFN3LzNJalhUSm9wR3phc05VclFEd2tpazJVcjFiaTNScGI3Vm8zRW9aQ0ZN?=
 =?utf-8?B?em9LZlZIMFRuMFdFRUZjZm45NktzTDZkZzFidWJIVldCTndBbVhsZmxBQnJD?=
 =?utf-8?B?VjZoVkxHSlFhQllJZm9Kc0NWUTgwajNzaS8wRjdheWZiR0o5bEIvMG9meUx5?=
 =?utf-8?B?STV4MEFhbDdpOWd6R1pEaUZJS0llOVV5RngydjAvU0RraWhTNjRYZlBQbE9K?=
 =?utf-8?B?NW9FeTZwNTh3YUpoblNIRkkwRHl3ZmpxNEs3QmpCYTNPWVJGejkxVVdUeXFi?=
 =?utf-8?B?QldCOUJNOUZrQmZlRDhJaFJlVTV0NXdSS21pUDZCY0NzNTZySGJxZ29LQXRi?=
 =?utf-8?B?amZ0bG9KQTNwZTg0TzJxODBEOU93cWtWUVJFSEtxZTFXVytDNnlGM3ByYjFu?=
 =?utf-8?B?OWR0M1lUei8vbC9TL0plMVNYaHU2VHU5dUtwb0pNYlk5dzJnamt5WGdiWUda?=
 =?utf-8?B?eGE0RWFkcWRjYkNNVVNVWFVhN0xnbUJlMVFuRTJ5ZjR5RDdEa0ZKSGZjRlRX?=
 =?utf-8?B?Vm5lZWJDTEdabno3U0pGVityZW1kcHJJSEZGa00rb1Y5ZXZZN2dhOWpkKzBM?=
 =?utf-8?B?WU8xeTdhSVB3OTlUb2FXZVRWTWxoZzcyMWZjdENiKzlDN1lyZFRnNiszVEM2?=
 =?utf-8?B?UmZCRUVGSm04cUF4VlMyTkhoS2pVWGRENHRPYUZ4Z1dzQW9OeVJpZXYvajhv?=
 =?utf-8?B?M1pzOU45R01oT2JLNlZwZ1AzM2FlNFlVaTB1dUdSSjYxQXAyU3FUdHFnS3hy?=
 =?utf-8?B?OXcxbmNPVFplMVQ4Sm51UGZVd0lqMzhwK0ZVMit0REpqRk9xVlUxNjZYZDh4?=
 =?utf-8?B?bXBkSTFYMlVuODNsYXJsNDRCY3BPVk1zWFN6SE5ubmsyMjNObXZVQWJTeklJ?=
 =?utf-8?B?YTE3c0l4SmFxTEdQK05GaHlTWFhBMEJ6cTQ3cGl1WTkvMEJYd21ya2pqOGtN?=
 =?utf-8?B?VXA1MEVVYnBEOFpiaWhPc2Vid0JxdUtYcXZ0TzlUVjVVZS9hMUZlcG55UDFy?=
 =?utf-8?B?MnA0UVZpbzNveXlrdGNFMlp5Tmd3bktlb2QyMjUraENpSXcxRVdYOTRRcm9T?=
 =?utf-8?B?aU1zUDNIcEZ1Zjhtam1uRkw0TytSb2NCNFh4RkVwNWRPU2xqOVQwK0oyamhh?=
 =?utf-8?B?ZnI0MklrNGRsTkM5NjBaUHliMjNHY0pNdnF4U0RuaGdtdzNlaWVmd252S3Fu?=
 =?utf-8?B?ZlVzSEdLWkVjMS9HbTJvMTNKMC8xRjYrSDBBQ2tTd1dmdmpQS2wwRW5FWDlT?=
 =?utf-8?B?Q24yYmVkZFlKWllSY3BEYWdodjRQS2RLWXROWFo5dU8wMDd4N3RybXJIY2cw?=
 =?utf-8?B?TklzV2hMR0FENU9XRENyMERXbWhKZ1RlSzFya1oxQkxHVGRWa095RVo4WlRY?=
 =?utf-8?B?Z0VLL2E5NW5HaGdXTXk0cVdieDM4MnRVelJkdGFyVDJHWE5GSXA2ZGU1K0s1?=
 =?utf-8?B?OXZXandueG9MdjA0TjFEamw2cG9NZ3NSU1VUUWFXVEZxRU9JTzc0K01QTGc3?=
 =?utf-8?B?eXVjZ3ZYTGk1T0ZPMWh6YU1ValRzcTZuSkNkRGlMQlV6R0pjNGMyS2ZnM08x?=
 =?utf-8?B?ZGc0aWo4cXZ6K3p1cWp4ZHdIWnFYTmprZUZuZjBHQ1oxZVNBV2dYQndGdFhi?=
 =?utf-8?B?bDBidW9MRDRQL1RUNXVOMEF3VXRCTnhjTEl2T09Vb1kvODlUQUhkVlNuQXc4?=
 =?utf-8?B?YzRwa1BLVGZjWWxYVVREL2N4TDlYd0NIY091ZUx6WXYyYk9MSkkrVURaNmNL?=
 =?utf-8?B?SmFudFVoUmpmdVpKekxPc0Y4UUFPV25IdlFtZ1hJTWZ6U2FwR3ZyYUtaRWhF?=
 =?utf-8?B?eVhQYmUzVDhvV3JSKzlRNUo0OVp6QzBINGQ5eXgzQ3kzMVpRRUxFdFJzQlJ3?=
 =?utf-8?B?K21XdGVkeUwvWmRlMDgxN20xV1RwOU1VWDN3SjNPa2tpTTFqdTEzUT09?=
X-OriginatorOrg: amd.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 2c3476d1-2d42-43c2-9078-08da28e98871
X-MS-Exchange-CrossTenant-AuthSource: DS7PR12MB6048.namprd12.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 28 Apr 2022 07:34:31.2667
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: Fmg+s4VssA/BMTAhZU6Vi8XZzVKDIOoH3g8ZTvSiOCaKAqwoWkigxnNmEf+bKuMOZjNXd1C/jiftji7GU+hIMw==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: BN8PR12MB3489
X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED,
        DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,NICE_REPLY_A,RCVD_IN_DNSWL_NONE,
        RCVD_IN_MSPIKE_H2,SPF_HELO_PASS,SPF_PASS 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

On 4/20/2022 4:59 PM, Suravee Suthikulpanit via iommu wrote:
> On AMD system with SNP enabled, IOMMU hardware checks the host translation
> valid (TV) and guest translation valid (GV) bits in the device
> table entry (DTE) before accessing the corresponded page tables.
> 
> However, current IOMMU driver sets the TV bit for all devices
> regardless of whether the host page table is in used.
> This results in ILLEGAL_DEV_TABLE_ENTRY event for devices, which
> do not the host page table root pointer set up.
> 
> Thefore, only set TV bit when host or guest page tables are in used.
> 
> Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>

Looks good to me.

Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>

-Vasant