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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?x/Rzkz34XrNeZle3qfwGUS1t/nkJwdLhDTfIib6WHufwWzAnxgdVOjxosQjU?= =?us-ascii?Q?tJhTrzdo/1EpR6hVK7Akikoa+J1vEUrJMDID0ttmUlSBEUrqO3hF+ZR5Ct9y?= =?us-ascii?Q?COGVAqoTB4cF0YnQGM/2eDDnNZoM1t0QiMutAWgAkC5L5alusJbZ6eneyEaw?= =?us-ascii?Q?EIDHgG33PrjxWlQ78OR+ytBUQGfST4ODB0ng7rnydqxhHSGvuhXLwReNe8M2?= =?us-ascii?Q?ODz0eJQ7QbpfH8uNe8Uvh4py4aDQdzn7PpM5BADTimXVI5oHCPdBoIsYDJLd?= =?us-ascii?Q?mSy7hzVprjSlW1bLYgsNEV0L59aJCbypHH42Ok3dNxlZ+ujDhqATHwqlRN3f?= =?us-ascii?Q?Ed+aQneNXrq+cxRt774ZXVc67pz5wjtIUr92COqax2scyCn1A1nAFxiyuEEJ?= =?us-ascii?Q?+2/AIUUdxANxOS87tQjt+hNH3ayS0+oMbRMqUno09HGP1PyVP2E/mxP0J2aG?= =?us-ascii?Q?20Z3cKHaYiZYTHJ8UbY92/rSQgoyaR5CW878XWMVIV8ac34MG5qaQn38byMN?= =?us-ascii?Q?0axOM/p752jkKYI2a0QwCzKPCYowt+od7KTJj4kJUui7GbmJ50WVkVSwUZp7?= =?us-ascii?Q?EwfyehDJUEAT97Eo50txH+6+/aa+Nu5JgMi/Ur+e4h6jxP4kUlxEKpACj6js?= =?us-ascii?Q?x+/gEe30eaFXMkg0J1/RsgDT/ZjOMUFDHUWhlplk9rhk2bmMmMjZLt/RJO4q?= =?us-ascii?Q?DQQuRKrqli+6N+jCG206ti1GOsmpBWQT0yNv6VyYIXHV0BLiNJMqM1RUSfdk?= =?us-ascii?Q?oVzekUKVpTMRMtSC7ODXcpRasQ7DCvBzjGiBWnQTZdgjAB1Z5b5cpUNK7Dzn?= =?us-ascii?Q?3XRm6vYZLzNzMBZKfM5u74jsY/g/ho0OTPo+iuYqFbuDPh4rH40UHh4iaEiE?= =?us-ascii?Q?VMBbwsd1JXnTCJOF70EKhFLh+CaACDIcifozdm4ubAOAadxIpo8B4+XdtJVu?= =?us-ascii?Q?049+Cptm1hM5RiB0aaRjWBQ6rsE4o9f4NEjL0weYdPxvowY/LbY77+nC9g9W?= =?us-ascii?Q?NQbw6SUfWZw05CGgsfkouu3bgfFR7L7VNThy37RmqL7zMcf0dDOMtBF9TsD7?= =?us-ascii?Q?YAYczOQv5cvdClI8vNZpJ7VDmW63mooLJ+s0TYeYwj2Z33sh0cZkXCCTm7i8?= =?us-ascii?Q?vTWG4E/xGsdaurmbncNBSDAHLmVAQufpLLak7AnTqw3t3qPfMfQGq6ECGmSV?= =?us-ascii?Q?W6HnyYp3wowGxMPmqufIXZ5khNqom0EY2pgZKnPurjIeZQcF6Fj7DwYG/gWG?= =?us-ascii?Q?gIlotvr6Revd9OOpbd7XDNeFwjXt7LQbM/YsWWwpPqBD/JCmUGPkJdNnZmsd?= =?us-ascii?Q?QgtCkPGD0KbacEoOWorCKe7rfjAG8jQC7oh/nxEAaM8X1y1dm/pUGLIKBTVm?= =?us-ascii?Q?1H7UJ42bsyWCNBdyCkUNTnjVKBLOB1PjvwKnorl4y/WTx+v+40liF21qg89Q?= =?us-ascii?Q?1YnBicNy3d3iziQovcYoC0uhRbIzexn2x9LkAwDviK5iw4k+Ll73bIpoQ9Lo?= =?us-ascii?Q?jqG2sg7suSufJm6L27SRmrrBuqSdFmF25K1TWoMMT9fNdUUWiA0gS/5WcHWo?= =?us-ascii?Q?i4s0qsfyp27PoWrEJjJy9S75VA3LLat+G0GbK4ivN1pB5MYzEPUsePDLVJRB?= =?us-ascii?Q?GKLN9QjzIJ8Fv/ONZjgSjJ0+flH/4vcXo72hF+XNQqMd2NIjh8h/ixXHf97/?= =?us-ascii?Q?RSveae3LIGLnx5MfLKVwVjWZPTiv3qJz7Zh4kzGreNuAPXE3?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: c648582b-e918-4250-9d4a-08df35056b93 X-MS-Exchange-CrossTenant-AuthSource: CHBPR12MB731189.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 28 Oct 2026 15:09:10.6886 (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: j7smtrWT72F2cT4fBvyIumPCmZi+rI5AHNeVe+BfbBlfNCFb8OB7Kt+9r25EZx9o X-MS-Exchange-Transport-CrossTenantHeadersStamped: IA1PR12MB6281 On Wed, Oct 28, 2026 at 02:19:17PM +0000, Shameer Kolothum Thodi wrote: > > + /* > > + * When in T=0 mode the T=1 vIOMMU must always be set to > > BLOCKED to > > + * release control of ATS. > > + */ > > + if (iommu_using_t0_stream(first)) { > > + if (!ops->blocked_domain) > > + return ERR_PTR(-EINVAL); > > + return ops->blocked_domain; > > How is MSI allocation handled for T=0 devices? The ITS calls > iommu_dma_prepare_msi(), which appears to return -EOPNOTSUPP > for the blocked domain. Is that intentional? For a TDISP capable devince MSI is always issued using T=0, meaning it does not go through the SMMU. It should be wired to defeat iommu_dma_prepare_msi() and use an identity IOVA as though there is no iommu present.. AFAIK this is true for all devices all arches today. Jason