| What: /sys/class/intel_pmt/features-<PCI BDF>/ |
| Date: 2025-04-24 |
| KernelVersion: 6.16 |
| Contact: david.e.box@linux.intel.com |
| Description: |
| The `features-<PCI BDF>/` directory represents the "features" |
| capability exposed by Intel PMT (Platform Monitoring Technology) |
| for the given PCI device. |
| |
| Each directory corresponds to a PMT feature and contains |
| attributes describing the available telemetry, monitoring, or |
| control functionalities. |
| |
| Directory Structure: |
| |
| /sys/class/intel_pmt/features-<PCI BDF>/ |
| ├── accelerator_telemetry/ # Per-accelerator telemetry data |
| ├── crash_log/ # Contains system crash telemetry logs |
| ├── per_core_environment_telemetry/ # Environmental telemetry per core |
| ├── per_core_performance_telemetry/ # Performance telemetry per core |
| ├── per_rmid_energy_telemetry/ # Energy telemetry for RMIDs |
| ├── per_rmid_perf_telemetry/ # Performance telemetry for RMIDs |
| ├── tpmi_control/ # TPMI-related controls and telemetry |
| ├── tracing/ # PMT tracing features |
| └── uncore_telemetry/ # Uncore telemetry data |
| |
| Common Files (Present in all feature directories): |
| |
| caps |
| - Read-only |
| - Lists available capabilities for this feature. |
| |
| guids |
| - Read-only |
| - Lists GUIDs associated with this feature. |
| |
| Additional Attributes (Conditional Presence): |
| |
| max_command_size |
| - Read-only |
| - Present if the feature supports out-of-band MCTP access. |
| - Maximum supported MCTP command size for out-of-band PMT access (bytes). |
| |
| max_stream_size |
| - Read-only |
| - Present if the feature supports out-of-band MCTP access. |
| - Maximum supported MCTP stream size (bytes). |
| |
| min_watcher_period_ms |
| - Read-only |
| - Present if the feature supports the watcher API. |
| The watcher API provides a writable control interface that allows user |
| configuration of monitoring behavior, such as setting the sampling or |
| reporting interval. |
| - Minimum supported time period for the watcher interface (milliseconds). |
| |
| num_rmids |
| - Read-only |
| - Present if the feature supports RMID (Resource Monitoring ID) telemetry. |
| RMIDs are identifiers used by hardware to track and report resource usage, |
| such as memory bandwidth or energy consumption, on a per-logical-entity |
| basis (e.g., per core, thread, or process group). |
| - Maximum number of RMIDs tracked simultaneously. |
| |
| Example: |
| For a device with PCI BDF `0000:00:03.1`, the directory tree could look like: |
| |
| /sys/class/intel_pmt/features-0000:00:03.1/ |
| ├── accelerator_telemetry/ |
| │ ├── caps |
| │ ├── guids |
| │ ├── max_command_size |
| │ ├── max_stream_size |
| │ ├── min_watcher_period_ms |
| ├── crash_log/ |
| │ ├── caps |
| │ ├── guids |
| │ ├── max_command_size |
| │ ├── max_stream_size |
| ├── per_core_environment_telemetry/ |
| │ ├── caps |
| │ ├── guids |
| │ ├── max_command_size |
| │ ├── max_stream_size |
| │ ├── min_watcher_period_ms |
| ├── per_rmid_energy_telemetry/ |
| │ ├── caps |
| │ ├── guids |
| │ ├── max_command_size |
| │ ├── max_stream_size |
| │ ├── min_watcher_period_ms |
| │ ├── num_rmids |
| ├── tpmi_control/ |
| │ ├── caps |
| │ ├── guids |
| ├── tracing/ |
| │ ├── caps |
| │ ├── guids |
| ├── uncore_telemetry/ |
| │ ├── caps |
| │ ├── guids |
| │ ├── max_command_size |
| │ ├── max_stream_size |
| │ ├── min_watcher_period_ms |
| |
| Notes: |
| - Some attributes are only present if the corresponding feature supports |
| the capability (e.g., `max_command_size` for MCTP-capable features). |
| - Features supporting RMIDs include `num_rmids`. |
| - Features supporting the watcher API include `min_watcher_period_ms`. |
| - The `caps` file provides additional information about the functionality |
| of the feature. |
| |
| Example 'caps' content for the 'tracing' feature: |
| |
| /sys/class/intel_pmt/features-0000:00:03.1/ |
| ├── tracing/ |
| │ ├── caps |
| |
| telemetry Available: No |
| watcher Available: Yes |
| crashlog Available: No |
| streaming Available: No |
| threashold Available: No |
| window Available: No |
| config Available: Yes |
| tracing Available: No |
| inband Available: Yes |
| oob Available: Yes |
| secure_chan Available: No |
| pmt_sp Available: Yes |
| pmt_sp_policy Available: Yes |
| mailbox Available: Yes |
| bios_lock Available: Yes |
