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, 27 Jun 2023 12:47:47 -0300
From:   Jason Gunthorpe <jgg@nvidia.com>
To:     Baolu Lu <baolu.lu@linux.intel.com>
Cc:     "Tian, Kevin" <kevin.tian@intel.com>,
        "Liu, Jingqi" <jingqi.liu@intel.com>,
        Joerg Roedel <joro@8bytes.org>, Will Deacon <will@kernel.org>,
        Robin Murphy <robin.murphy@arm.com>,
        Alex Williamson <alex.williamson@redhat.com>,
        Nicolin Chen <nicolinc@nvidia.com>,
        "iommu@lists.linux.dev" <iommu@lists.linux.dev>,
        "kvm@vger.kernel.org" <kvm@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 1/2] iommu: Prevent RESV_DIRECT devices from blocking
 domains
Message-ID: <ZJsEo2eqDdV0Mska@nvidia.com>
References: <20230607035145.343698-1-baolu.lu@linux.intel.com>
 <20230607035145.343698-2-baolu.lu@linux.intel.com>
 <8cc1d69e-f86d-fd04-7737-914d967dc0f5@intel.com>
 <69f50ced-e806-717a-0c74-a4cfa58600fa@linux.intel.com>
 <BN9PR11MB52768ACA721898D5C43CBE9B8C27A@BN9PR11MB5276.namprd11.prod.outlook.com>
 <f1b2e7fa-7be3-9e4b-1eba-5dba01b88c19@linux.intel.com>
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <f1b2e7fa-7be3-9e4b-1eba-5dba01b88c19@linux.intel.com>
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?6K+xNobNZgSmkSwg23rV5+ifCfp5wfC+lls2Sa1lPgcJoSZcP4PXDkDNWh6U?=
 =?us-ascii?Q?88yVrRdRsiAVYbY9NmF/8hpMK5UXt9rUOaixUGvIpsrWG4vEDlMOwjcmhNWn?=
 =?us-ascii?Q?B5P4a4s3/x8PGsQYCK2FN6vfa9DZf8ciGfouKEA4lvrXMg5nr8fuM8cItAQt?=
 =?us-ascii?Q?BKI2uPuySJQjmJSVmjlnEzA5h/NnKUQBmfc36vTQ4XwiVCMRLf4UfWUncdyT?=
 =?us-ascii?Q?rX5Wjfnwr+jx4kx/+fk/07sE9owa1Mpd9CUjSvMzdYVMHJXg8Da0Q4w2hAvY?=
 =?us-ascii?Q?GzESQHZVgyy1kkuB643usjiOEhp3VDiCsJPZd98jiAIK8I9SfYvw8mHfXH7h?=
 =?us-ascii?Q?TiBnf1jaHBvyZZ7XBznbb2AsaloFKOiSVuJDDoYbMZuVbiR8qBkLX4iOrsO6?=
 =?us-ascii?Q?TjJ/Vum48zwHI5r7+ZS/nc+Aap4pkNwJSgTh2hznt9gQ9K1h9AQZtg7l/1ZB?=
 =?us-ascii?Q?03C7H5/9Fljw0vAebzIytRY+wwjbQNh7o7+XLwojHJVVSM7ZosLeKCwob0IR?=
 =?us-ascii?Q?28qtjjYgYSdFoJhcTmNGlxMxO4MNKxMHHenxJ+zvMDG2+XrOAylqIBex9gI0?=
 =?us-ascii?Q?tfAdFCOYnRuPwenqaQplcThwiv0uPo1R4f2Q/7RS5nmB+bsngYj5zFBQ718s?=
 =?us-ascii?Q?pXYSiUBOY2Ef2K4lykwB4WxTs+ar69YrHzXwRIM9iFiz6iuDEyuOjO9bP1xa?=
 =?us-ascii?Q?Sq1+nV2PvYDFGZOw4ET31g+u39IyYomjNgPL5KCGuF1qOOgk+A883u2NMtuI?=
 =?us-ascii?Q?LH2q6TvjPI+GEX1aluWw2O3hh+yqF/yocEOyqsvy58cKvi/9yZUXMy5zSDcV?=
 =?us-ascii?Q?y3+AJSripxgE094sSiRyWHoUxm9+8oSt+/J9LNi0GHGWoBhRUa9l6mpQ6EpO?=
 =?us-ascii?Q?F2/VKj8zROYVFWlVB3FWsbfyKm85WknaeA82luggVDfQcvEZIfBnelaYw+HS?=
 =?us-ascii?Q?mU7dOL0y0S0/siVRjKLjrQ2qOz0/dCZYRdXWsE7Z+QW7BSMUA4Gh5Ns+EbOn?=
 =?us-ascii?Q?hJsBvExBuMRG39SehCbqiCh7n3JkwfJ/2hZNqN0GPULW4cIibEfJIPcMfB5F?=
 =?us-ascii?Q?3lEDpWEJUTp89R4WkwAIGglA9HB++5zWKBqYD6elKi5Y//jrnV446AqdZ5jq?=
 =?us-ascii?Q?I/WWCwg6+iM+ASW1botWJWzAbp5/SQnBL513Mvvbd+bGRtxVHNvcx+ztf8xj?=
 =?us-ascii?Q?4U8ZJB4ySiHJfu5b8v+MM/njNA5hyoa1eq8RddcXNmrgTj9DBSfAE69OAs0Z?=
 =?us-ascii?Q?y9PQvb8QnSaiNRUN6MKGiCVdPKQuPPPa2/gpa0NrYGYs9XlKeFQ4R9T40kXk?=
 =?us-ascii?Q?Mh+TjFsGicFRjNYVSnHlsIzAMbpgWxmcM4LDElRtmKKTVB/F6vtRT5JInJNS?=
 =?us-ascii?Q?GUIwwWc2TJCxQ30COEsweE0W8/da/uegwVUWhhOCY39O41AFfEh/WS9u38+Q?=
 =?us-ascii?Q?+Q5saqI/+mX1hQVnBf5KrkxWpIohXy2Uc7MAgRd7YGegBa4EcTP3fx3kTk38?=
 =?us-ascii?Q?bAD7WsEDJUKNbrpwfp5GxAMAzyQhIpJGTwY7vHhzSuFuRwPSlVcgtGiq2EVu?=
 =?us-ascii?Q?D5X2E0rMCFKNRVmRfKeCouUfvche2xY9U0NebdjY?=
X-OriginatorOrg: Nvidia.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 8a6f34fe-be7d-43f7-0d0a-08db7725db7d
X-MS-Exchange-CrossTenant-AuthSource: LV2PR12MB5869.namprd12.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 27 Jun 2023 15:47:48.5268
 (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: qu+zWJzrPFjR6ARTEyrFqXG1YBFP9POIoP8u/CrpplsKjGyNFPn+VTtmgaQNoppq
X-MS-Exchange-Transport-CrossTenantHeadersStamped: BL1PR12MB5922
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 27, 2023 at 04:01:01PM +0800, Baolu Lu wrote:

> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
> index e59de7852067..3be88b5f36bb 100644
> --- a/drivers/iommu/iommu.c
> +++ b/drivers/iommu/iommu.c
> @@ -962,6 +962,9 @@ static int iommu_create_device_direct_mappings(struct
> iommu_domain *domain,
>         pg_size = domain->pgsize_bitmap ? 1UL <<
> __ffs(domain->pgsize_bitmap) : 0;
>         INIT_LIST_HEAD(&mappings);
> 
> +       if (WARN_ON_ONCE((domain->type & __IOMMU_DOMAIN_PAGING) &&
> !pg_size))
> +               return -EINVAL;

Calling this function with an identity domain is expected, it must
return 0.

Jason