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;
Date:   Tue, 20 Jun 2023 13:55:47 -0300
From:   Jason Gunthorpe <jgg@nvidia.com>
To:     Alexander Duyck <alexander.duyck@gmail.com>
Cc:     Robin Murphy <robin.murphy@arm.com>,
        "Tian, Kevin" <kevin.tian@intel.com>,
        Alex Williamson <alex.williamson@redhat.com>,
        Baolu Lu <baolu.lu@linux.intel.com>,
        LKML <linux-kernel@vger.kernel.org>,
        linux-pci <linux-pci@vger.kernel.org>,
        "iommu@lists.linux.dev" <iommu@lists.linux.dev>
Subject: Re: Question about reserved_regions w/ Intel IOMMU
Message-ID: <ZJHaE2+XOgQj1q2k@nvidia.com>
References: <b24a6c7b-27fc-41c0-5c82-15696b4a7dc1@arm.com>
 <ZIiRK2Dzl2/9Jqle@ziepe.ca>
 <BN9PR11MB52765C24405D2475CF3CBEBE8C58A@BN9PR11MB5276.namprd11.prod.outlook.com>
 <ZIxTmGU4a5dniEY3@nvidia.com>
 <CAKgT0UfmdOOPSD5YvpHnh1A02URn9zxVLbyXJM_67On7xojLcA@mail.gmail.com>
 <520e2be4-726f-c680-c010-a308cdddbae0@arm.com>
 <ZIyxFpzh3WG+ifws@nvidia.com>
 <90823b33-1f44-8789-9a38-282407fd9f15@arm.com>
 <ZJBf5DP60prFH5R2@nvidia.com>
 <CAKgT0UccM=_D-gJdzjqeUmRZWnSHVaUABjgQBEamLYauE8WTCA@mail.gmail.com>
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <CAKgT0UccM=_D-gJdzjqeUmRZWnSHVaUABjgQBEamLYauE8WTCA@mail.gmail.com>
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?fWu9HNs0cKirJtu13Ak5fE1RNO8x+3+mftJjCV1gUoaodetxIPxFzMYcK3B8?=
 =?us-ascii?Q?a5YwRQ6ldzzQ4J6xjMSJ8s6D764Eiw7EbOLT21/eXSfB81rLEZkYJHXawMyk?=
 =?us-ascii?Q?8yVSu/iU+bFgwRHwY3+oTsrpVS9yPchIsWk+76WcmC1A66CeEvXdI/pHiVI/?=
 =?us-ascii?Q?zj4uEnQYkkwgeWTZEzgwMWHNPuP4gxwJBZDmjmorc/F1vuwQYsVI87xOD99s?=
 =?us-ascii?Q?UR2kZX/vTMzJ8Glbu6l7og+/JAtS49ixpxuns14KYv33Yg3cgDvcL2EZ9sEO?=
 =?us-ascii?Q?ZpAo0xD8suWO3V3kFZC67nq3xlCMINz5oxY9V229uv7QOnjGL0++JB8Y3/ZZ?=
 =?us-ascii?Q?BAd3MPUsxB/MLrlbp5pXa9l/09Dw2fOUP7j6s3YxqkagsdK6NNHWmwa7eegP?=
 =?us-ascii?Q?HJuXSpYSsxejP1SAebFAKQjfbWQoyviXJcTIIXMl0al1JhPvI+6YU8WP4MNA?=
 =?us-ascii?Q?YPX5GX6V/NIXU8FV/ZHIz/TDeuUTR/PGt8Gp37N+TnF2/UTGUeU8Eq8nSHJQ?=
 =?us-ascii?Q?JSlChAor41TXBCJtlTtaSWCb04fLshLUieT54lRMDZVpQpBRKbeLe3Gf1zcX?=
 =?us-ascii?Q?p4eY79rV0Rcka494bSwOb2+I1jbyQsmgy6JgYjhcIzq7mtwTqMWL0LtL8qsw?=
 =?us-ascii?Q?CmAFqMLURp599jsK/P9e7MESlroNpsGrnlyRUbFJP0GyumM6v9bJFuZ/esU5?=
 =?us-ascii?Q?QYHnaJmaFw1RGaIykz0rA7eePTDQfWbE923SbU8VWl0v1aeYae/yUs83ujVU?=
 =?us-ascii?Q?PGU2cOfUchjHRNLjkONYFN6Jk3neJInjAA9v0EARO+egAmm5UIiQXRDqqtsI?=
 =?us-ascii?Q?5vwK96MrkoIxDQjdGYMuGDn+tz3Qg8ovXnvmMnREW8Gpd/BZTik1bk70Z98f?=
 =?us-ascii?Q?VgPl889FPqBwdqhf8uB+SWDqSXQnZg92v5ieqcacxycaYWtx8+7Yz2eMn+Hu?=
 =?us-ascii?Q?2kq3gCRbPnfPOyHI1f0mXo4K34qxif1GLOnGvHiinjjN/LmwrVLQmHT+AUSj?=
 =?us-ascii?Q?hR8a8PCbYYCXK5l+YBlLwVO7bZVAbeapsaKS3SEo9QtuTq5+N8PEP/txh3MB?=
 =?us-ascii?Q?t1zC4+WKMyCimtgCj0bg24rSb9DjQGGgmamuU+H4+z6/dc7+OGz1fuPSZ7KT?=
 =?us-ascii?Q?VdN1V7Cc405kHBKXsjIAApw9iwgRGenGEChcV5405b1mR8yodOH3BM4PiMKx?=
 =?us-ascii?Q?H8Gn+VBhHJQtg213Xgf4uao0rAOKe5lQ9cj8sHV8H7VtLy++nGAckgWPfwoA?=
 =?us-ascii?Q?kqckcGclAq3teTEqLn9YpxN4fKm0YZessMy0wF1SBwEqBV2XEGq2Fcp2mtb9?=
 =?us-ascii?Q?RYGmTBqBGoUhXXet5bJ4yQFzMbXVIjv4VJTZ5zGGxRoNuwfrsgRxlJ2MmUSW?=
 =?us-ascii?Q?K0XigGMrLfbDWVhoI0M2xsTyZBJNzVZVhvGmoocD9lxGG3cECVyu4DM5111M?=
 =?us-ascii?Q?fzzxQQE70PTGjdDLe244gsfN+FnQM7l+a+AeAwbKk1wCxibRODeWOBkP16j2?=
 =?us-ascii?Q?cdk2bZ+SiOC/kKK3QVKcRgxZSQbqOv5TBJkd7kAUA1P1jU6oo6880DhmyhTH?=
 =?us-ascii?Q?hUi5fUWov/dFk8Wreu/wsxWHnYYkh98wILUVnkDN?=
X-OriginatorOrg: Nvidia.com
X-MS-Exchange-CrossTenant-Network-Message-Id: d1447e5a-0b32-46f1-6f40-08db71af328f
X-MS-Exchange-CrossTenant-AuthSource: LV2PR12MB5869.namprd12.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 20 Jun 2023 16:55:48.6129
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: sl8nYGIWstL9k2HxrEi03LwQlfrGsGU0Yrg5XpboMTfLXWRtWj2ytoQo5Arp5czi
X-MS-Exchange-Transport-CrossTenantHeadersStamped: BY5PR12MB4307
X-Spam-Status: No, score=-1.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,
        DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FORGED_SPF_HELO,
        RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H2,SPF_HELO_PASS,SPF_NONE,
        T_SCC_BODY_TEXT_LINE,URIBL_BLOCKED autolearn=no 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 Tue, Jun 20, 2023 at 07:57:57AM -0700, Alexander Duyck wrote:

> I think this may have gone off down a rathole as my original question
> wasn't anything about adding extra reserved regions. It was about
> exposing what the IOVA is already reserving so it could be user
> visible.

Your question points out that dma-iommu.c uses a different set of
reserved regions than everything else, and its set is closer to
functionally correct.

IMHO the resolution to what you are talking about is not to add more
debugging to dma-iommu but to make the set of reserved regions
consistently correct for everyone, which will make them viewable in
sysfs.

Jason