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
