Documentation/ABI/testing/debugfs-driver-qat_telemetry
What: /sys/kernel/debug/qat_<device>_<BDF>/telemetry/control
Date: March 2024
KernelVersion: 6.8
Contact: qat-linux@intel.com
Description: (RW) Enables/disables the reporting of telemetry metrics.
Allowed values to write:
========================
* 0: disable telemetry
* 1: enable telemetry
* 2, 3, 4: enable telemetry and calculate minimum, maximum
and average for each counter over 2, 3 or 4 samples
Returned values:
================
* 1-4: telemetry is enabled and running
* 0: telemetry is disabled
Example.
Writing '3' to this file starts the collection of
telemetry metrics. Samples are collected every second and
stored in a circular buffer of size 3. These values are then
used to calculate the minimum, maximum and average for each
counter. After enabling, counters can be retrieved through
the ``device_data`` file::
echo 3 > /sys/kernel/debug/qat_4xxx_0000:6b:00.0/telemetry/control
Writing '0' to this file stops the collection of telemetry
metrics::
echo 0 > /sys/kernel/debug/qat_4xxx_0000:6b:00.0/telemetry/control
This attribute is only available for qat_4xxx devices.
What: /sys/kernel/debug/qat_<device>_<BDF>/telemetry/device_data
Date: March 2024
KernelVersion: 6.8
Contact: qat-linux@intel.com
Description: (RO) Reports device telemetry counters.
Reads report metrics about performance and utilization of
a QAT device:
======================= ========================================
Field Description
======================= ========================================
sample_cnt number of acquisitions of telemetry data
from the device. Reads are performed
every 1000 ms.
pci_trans_cnt number of PCIe partial transactions
max_rd_lat maximum logged read latency [ns] (could
be any read operation)
rd_lat_acc_avg average read latency [ns]
max_gp_lat max get to put latency [ns] (only takes
samples for AE0)
gp_lat_acc_avg average get to put latency [ns]
bw_in PCIe, write bandwidth [Mbps]
bw_out PCIe, read bandwidth [Mbps]
at_page_req_lat_avg Address Translator(AT), average page
request latency [ns]
at_trans_lat_avg AT, average page translation latency [ns]
at_max_tlb_used AT, maximum uTLB used
util_cpr<N> utilization of Compression slice N [%]
exec_cpr<N> execution count of Compression slice N
util_xlt<N> utilization of Translator slice N [%]
exec_xlt<N> execution count of Translator slice N
util_dcpr<N> utilization of Decompression slice N [%]
exec_dcpr<N> execution count of Decompression slice N
util_pke<N> utilization of PKE N [%]
exec_pke<N> execution count of PKE N
util_ucs<N> utilization of UCS slice N [%]
exec_ucs<N> execution count of UCS slice N
util_wat<N> utilization of Wireless Authentication
slice N [%]
exec_wat<N> execution count of Wireless Authentication
slice N
util_wcp<N> utilization of Wireless Cipher slice N [%]
exec_wcp<N> execution count of Wireless Cipher slice N
util_cph<N> utilization of Cipher slice N [%]
exec_cph<N> execution count of Cipher slice N
util_ath<N> utilization of Authentication slice N [%]
exec_ath<N> execution count of Authentication slice N
======================= ========================================
The telemetry report file can be read with the following command::
cat /sys/kernel/debug/qat_4xxx_0000:6b:00.0/telemetry/device_data
If ``control`` is set to 1, only the current values of the
counters are displayed::
<counter_name> <current>
If ``control`` is 2, 3 or 4, counters are displayed in the
following format::
<counter_name> <current> <min> <max> <avg>
If a device lacks of a specific accelerator, the corresponding
attribute is not reported.
This attribute is only available for qat_4xxx devices.
What: /sys/kernel/debug/qat_<device>_<BDF>/telemetry/rp_<A/B/C/D>_data
Date: March 2024
KernelVersion: 6.8
Contact: qat-linux@intel.com
Description: (RW) Selects up to 4 Ring Pairs (RP) to monitor, one per file,
and report telemetry counters related to each.
Allowed values to write:
========================
* 0 to ``<num_rps - 1>``:
Ring pair to be monitored. The value of ``num_rps`` can be
retrieved through ``/sys/bus/pci/devices/<BDF>/qat/num_rps``.
See Documentation/ABI/testing/sysfs-driver-qat.
Reads report metrics about performance and utilization of
the selected RP:
======================= ========================================
Field Description
======================= ========================================
sample_cnt number of acquisitions of telemetry data
from the device. Reads are performed
every 1000 ms
rp_num RP number associated with slot <A/B/C/D>
service_type service associated to the RP
pci_trans_cnt number of PCIe partial transactions
gp_lat_acc_avg average get to put latency [ns]
bw_in PCIe, write bandwidth [Mbps]
bw_out PCIe, read bandwidth [Mbps]
at_glob_devtlb_hit Message descriptor DevTLB hit rate
at_glob_devtlb_miss Message descriptor DevTLB miss rate
tl_at_payld_devtlb_hit Payload DevTLB hit rate
tl_at_payld_devtlb_miss Payload DevTLB miss rate
======================= ========================================
Example.
Writing the value '32' to the file ``rp_C_data`` starts the
collection of telemetry metrics for ring pair 32::
echo 32 > /sys/kernel/debug/qat_4xxx_0000:6b:00.0/telemetry/rp_C_data
Once a ring pair is selected, statistics can be read accessing
the file::
cat /sys/kernel/debug/qat_4xxx_0000:6b:00.0/telemetry/rp_C_data
If ``control`` is set to 1, only the current values of the
counters are displayed::
<counter_name> <current>
If ``control`` is 2, 3 or 4, counters are displayed in the
following format::
<counter_name> <current> <min> <max> <avg>
On QAT GEN4 devices there are 64 RPs on a PF, so the allowed
values are 0..63. This number is absolute to the device.
If Virtual Functions (VF) are used, the ring pair number can
be derived from the Bus, Device, Function of the VF:
============ ====== ====== ====== ======
PCI BDF/VF RP0 RP1 RP2 RP3
============ ====== ====== ====== ======
0000:6b:0.1 RP 0 RP 1 RP 2 RP 3
0000:6b:0.2 RP 4 RP 5 RP 6 RP 7
0000:6b:0.3 RP 8 RP 9 RP 10 RP 11
0000:6b:0.4 RP 12 RP 13 RP 14 RP 15
0000:6b:0.5 RP 16 RP 17 RP 18 RP 19
0000:6b:0.6 RP 20 RP 21 RP 22 RP 23
0000:6b:0.7 RP 24 RP 25 RP 26 RP 27
0000:6b:1.0 RP 28 RP 29 RP 30 RP 31
0000:6b:1.1 RP 32 RP 33 RP 34 RP 35
0000:6b:1.2 RP 36 RP 37 RP 38 RP 39
0000:6b:1.3 RP 40 RP 41 RP 42 RP 43
0000:6b:1.4 RP 44 RP 45 RP 46 RP 47
0000:6b:1.5 RP 48 RP 49 RP 50 RP 51
0000:6b:1.6 RP 52 RP 53 RP 54 RP 55
0000:6b:1.7 RP 56 RP 57 RP 58 RP 59
0000:6b:2.0 RP 60 RP 61 RP 62 RP 63
============ ====== ====== ====== ======
The mapping is only valid for the BDFs of VFs on the host.
The service provided on a ring-pair varies depending on the
configuration. The configuration for a given device can be
queried and set using ``cfg_services``.
See Documentation/ABI/testing/sysfs-driver-qat for details.
The following table reports how ring pairs are mapped to VFs
on the PF 0000:6b:0.0 configured for `sym;asym` or `asym;sym`:
=========== ============ =========== ============ ===========
PCI BDF/VF RP0/service RP1/service RP2/service RP3/service
=========== ============ =========== ============ ===========
0000:6b:0.1 RP 0 asym RP 1 sym RP 2 asym RP 3 sym
0000:6b:0.2 RP 4 asym RP 5 sym RP 6 asym RP 7 sym
0000:6b:0.3 RP 8 asym RP 9 sym RP10 asym RP11 sym
... ... ... ... ...
=========== ============ =========== ============ ===========
All VFs follow the same pattern.
The following table reports how ring pairs are mapped to VFs on
the PF 0000:6b:0.0 configured for `dc`:
=========== ============ =========== ============ ===========
PCI BDF/VF RP0/service RP1/service RP2/service RP3/service
=========== ============ =========== ============ ===========
0000:6b:0.1 RP 0 dc RP 1 dc RP 2 dc RP 3 dc
0000:6b:0.2 RP 4 dc RP 5 dc RP 6 dc RP 7 dc
0000:6b:0.3 RP 8 dc RP 9 dc RP10 dc RP11 dc
... ... ... ... ...
=========== ============ =========== ============ ===========
The mapping of a RP to a service can be retrieved using
``rp2srv`` from sysfs.
See Documentation/ABI/testing/sysfs-driver-qat for details.
This attribute is only available for qat_4xxx devices.