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| 1 | +What: /sys/class/intel_pmt/features-<PCI BDF>/ |
| 2 | +Date: 2025-04-24 |
| 3 | +KernelVersion: 6.16 |
| 4 | + |
| 5 | +Description: |
| 6 | + The `features-<PCI BDF>/` directory represents the "features" |
| 7 | + capability exposed by Intel PMT (Platform Monitoring Technology) |
| 8 | + for the given PCI device. |
| 9 | + |
| 10 | + Each directory corresponds to a PMT feature and contains |
| 11 | + attributes describing the available telemetry, monitoring, or |
| 12 | + control functionalities. |
| 13 | + |
| 14 | +Directory Structure: |
| 15 | + |
| 16 | + /sys/class/intel_pmt/features-<PCI BDF>/ |
| 17 | + ├── accelerator_telemetry/ # Per-accelerator telemetry data |
| 18 | + ├── crash_log/ # Contains system crash telemetry logs |
| 19 | + ├── per_core_environment_telemetry/ # Environmental telemetry per core |
| 20 | + ├── per_core_performance_telemetry/ # Performance telemetry per core |
| 21 | + ├── per_rmid_energy_telemetry/ # Energy telemetry for RMIDs |
| 22 | + ├── per_rmid_perf_telemetry/ # Performance telemetry for RMIDs |
| 23 | + ├── tpmi_control/ # TPMI-related controls and telemetry |
| 24 | + ├── tracing/ # PMT tracing features |
| 25 | + └── uncore_telemetry/ # Uncore telemetry data |
| 26 | + |
| 27 | +Common Files (Present in all feature directories): |
| 28 | + |
| 29 | + caps |
| 30 | + - Read-only |
| 31 | + - Lists available capabilities for this feature. |
| 32 | + |
| 33 | + guids |
| 34 | + - Read-only |
| 35 | + - Lists GUIDs associated with this feature. |
| 36 | + |
| 37 | +Additional Attributes (Conditional Presence): |
| 38 | + |
| 39 | + max_command_size |
| 40 | + - Read-only |
| 41 | + - Present if the feature supports out-of-band MCTP access. |
| 42 | + - Maximum supported MCTP command size for out-of-band PMT access (bytes). |
| 43 | + |
| 44 | + max_stream_size |
| 45 | + - Read-only |
| 46 | + - Present if the feature supports out-of-band MCTP access. |
| 47 | + - Maximum supported MCTP stream size (bytes). |
| 48 | + |
| 49 | + min_watcher_period_ms |
| 50 | + - Read-only |
| 51 | + - Present if the feature supports the watcher API. |
| 52 | + The watcher API provides a writable control interface that allows user |
| 53 | + configuration of monitoring behavior, such as setting the sampling or |
| 54 | + reporting interval. |
| 55 | + - Minimum supported time period for the watcher interface (milliseconds). |
| 56 | + |
| 57 | + num_rmids |
| 58 | + - Read-only |
| 59 | + - Present if the feature supports RMID (Resource Monitoring ID) telemetry. |
| 60 | + RMIDs are identifiers used by hardware to track and report resource usage, |
| 61 | + such as memory bandwidth or energy consumption, on a per-logical-entity |
| 62 | + basis (e.g., per core, thread, or process group). |
| 63 | + - Maximum number of RMIDs tracked simultaneously. |
| 64 | + |
| 65 | +Example: |
| 66 | +For a device with PCI BDF `0000:00:03.1`, the directory tree could look like: |
| 67 | + |
| 68 | + /sys/class/intel_pmt/features-0000:00:03.1/ |
| 69 | + ├── accelerator_telemetry/ |
| 70 | + │ ├── caps |
| 71 | + │ ├── guids |
| 72 | + │ ├── max_command_size |
| 73 | + │ ├── max_stream_size |
| 74 | + │ ├── min_watcher_period_ms |
| 75 | + ├── crash_log/ |
| 76 | + │ ├── caps |
| 77 | + │ ├── guids |
| 78 | + │ ├── max_command_size |
| 79 | + │ ├── max_stream_size |
| 80 | + ├── per_core_environment_telemetry/ |
| 81 | + │ ├── caps |
| 82 | + │ ├── guids |
| 83 | + │ ├── max_command_size |
| 84 | + │ ├── max_stream_size |
| 85 | + │ ├── min_watcher_period_ms |
| 86 | + ├── per_rmid_energy_telemetry/ |
| 87 | + │ ├── caps |
| 88 | + │ ├── guids |
| 89 | + │ ├── max_command_size |
| 90 | + │ ├── max_stream_size |
| 91 | + │ ├── min_watcher_period_ms |
| 92 | + │ ├── num_rmids |
| 93 | + ├── tpmi_control/ |
| 94 | + │ ├── caps |
| 95 | + │ ├── guids |
| 96 | + ├── tracing/ |
| 97 | + │ ├── caps |
| 98 | + │ ├── guids |
| 99 | + ├── uncore_telemetry/ |
| 100 | + │ ├── caps |
| 101 | + │ ├── guids |
| 102 | + │ ├── max_command_size |
| 103 | + │ ├── max_stream_size |
| 104 | + │ ├── min_watcher_period_ms |
| 105 | + |
| 106 | +Notes: |
| 107 | + - Some attributes are only present if the corresponding feature supports |
| 108 | + the capability (e.g., `max_command_size` for MCTP-capable features). |
| 109 | + - Features supporting RMIDs include `num_rmids`. |
| 110 | + - Features supporting the watcher API include `min_watcher_period_ms`. |
| 111 | + - The `caps` file provides additional information about the functionality |
| 112 | + of the feature. |
| 113 | + |
| 114 | +Example 'caps' content for the 'tracing' feature: |
| 115 | + |
| 116 | + /sys/class/intel_pmt/features-0000:00:03.1/ |
| 117 | + ├── tracing/ |
| 118 | + │ ├── caps |
| 119 | + |
| 120 | + telemetry Available: No |
| 121 | + watcher Available: Yes |
| 122 | + crashlog Available: No |
| 123 | + streaming Available: No |
| 124 | + threashold Available: No |
| 125 | + window Available: No |
| 126 | + config Available: Yes |
| 127 | + tracing Available: No |
| 128 | + inband Available: Yes |
| 129 | + oob Available: Yes |
| 130 | + secure_chan Available: No |
| 131 | + pmt_sp Available: Yes |
| 132 | + pmt_sp_policy Available: Yes |
| 133 | + mailbox Available: Yes |
| 134 | + bios_lock Available: Yes |
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