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Peter Anvin" , Penny Zheng , , References: <20260623211904.3674-1-jason.andryuk@amd.com> <20260623213552.GAajr8ONjXFUnuUOE3@fat_crate.local> <48629f88-4b78-424e-a199-d87594c8cb40@amd.com> <20260624155910.GCajv-zguf0GiBxt2F@fat_crate.local> Content-Language: en-US From: Jason Andryuk In-Reply-To: <20260624155910.GCajv-zguf0GiBxt2F@fat_crate.local> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: SN1PEPF000397B1:EE_|SA1PR12MB7269:EE_ X-MS-Office365-Filtering-Correlation-Id: 022d1f76-e094-4e2e-130e-08ded20f7f65 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|82310400026|23010399003|1800799024|36860700016|4143699003|11063799006|3023799007|56012099006|22082099003|18002099003; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:165.204.84.17;CTRY:US;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:satlexmb07.amd.com;PTR:InfoDomainNonexistent;CAT:NONE;SFS:(13230040)(376014)(82310400026)(23010399003)(1800799024)(36860700016)(4143699003)(11063799006)(3023799007)(56012099006)(22082099003)(18002099003);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: uGHpujhnVcLwqoJ1Nwyn/GIAHM/kl/mxka5uZBfRIHdrzt6yXm/1OTAT5oCFi3QaNxObxbt2Sn0jKHmCDII3In4DNb933cXiTAbcFq3uP+43LzOZvS6pooW/OUik2bjQM5fKSVAeqi3zpzAC0u9+YowLEM5u9d0yW3wTUzvcs354tkbPRw3mrgnT4/57bmkiTN6I2DhIut4/3oqgqYpeMFYiHGBrjs6EaWFC10rF/dLaTYgA73KDw7LtISNNDD/rhpPQPUfZ7uQ+ReYvUn3NLm8axShTd7MjtCzcUsNmXp9WXAFZ3oYTJNgLDyuTw3UKRKrATC01P3cY7AY2fTw7mcsqjFUhrcdLfMl0my/aNmDodjJzRgk2Vr0b47IEYLcbx0C5mvdnHzcF/489kV1CTY5T9H346/BjRBq2V9ywGYl/b2UHh1eFtrr3SW05cWnW X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 24 Jun 2026 16:41:53.6224 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 022d1f76-e094-4e2e-130e-08ded20f7f65 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=[satlexmb07.amd.com] X-MS-Exchange-CrossTenant-AuthSource: SN1PEPF000397B1.namprd05.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: SA1PR12MB7269 On 2026-06-24 11:59, Borislav Petkov wrote: > + Andy > > On Wed, Jun 24, 2026 at 11:41:16AM -0400, Jason Andryuk wrote: >> I have wip s0ix support with Xen where dom0 issues the amd-pmc calls to >> enter s0ix. I'm not sure of all the uses of SMN, but with Xen dom0/hardware >> domain running most drivers, I think it should be available. > > Well, how should we make it available if dom0 doesn't really allow us to > enumerate PCI roots and thus count AMD nodes? dom0 enumerates the physical PCI roots. It's just the dom0 vCPUs and topology are synthetic. > Andy, see upthread. > > What would you suggest we do here on dom0? We're trying to enumerate AMD > nodes but dom0 is doing something special wrt topology and PCI roots - see > get_next_root() in amd_node.c. > > Thx. > I think this is the issue: The "root" device search was introduced to support SMN access for Zen systems. This device represents a PCIe root complex. It is not the same as the "CPU/node" devices found at slots 0x18-0x1F. We don't want dom0 to access the "CPU/node" devices. It's the "root" device SMN access I am trying to retain. Many amd_smn_read/write calls have hardcoded node 0, like for amd-pmc. Regards, Jason