Public bug reported:
Fix CPU-MF error on new IBM Z Hardware by adding support for CPU-MF
counter second version 7
Error Symptom: Daemon cpacfstatsd fails on start up of the system
with this error message
cpacfstatsd: Event DEA_FUNCTIONS for pmu cpum_cf
not found (2:No such file or directory)
Problem: When the CPU Measurement facility device driver
is initialized during kernel boot, it reads out the
CPU Measurement facility counter hardware first and
second version numbers. Depending on these numbers
the device driver exports attributes in the sysfs
directory /sys/devices/cpum_cf/events. When the
CPM-MF second version number is not known, no
attributes of the crypto counter set are exported.
However the cpacfstatsd program scans the sysfs
directory /sys/devices/cpum_cf/events for attribute
files of the crypto counter set, for example attribute
file DEA_FUNCTIONS and others.
Solution: Add support for the new CPU-MF Measurement counter
facility second version number 7. This number then
exports the crypto counter set in directory
directory /sys/devices/cpum_cf/events.
Also add support for limited samples. These hardware
samples contain all zeroes and are of no value when
using the CPU Measurement Facility sampling hardware.
Drop these samples when the limited sampled bit is set
in the sample descriptor.
Reproduction: Run command ls -l /sys/devices/cpum_cf/events |
fgrep DEA
DEA_BLOCKED_CYCLES
DEA_BLOCKED_FUNCTIONS
DEA_CYCLES
DEA_FUNCTIONS
When there is no output at all the attributes files
for the crypto counter set have not been exported.
If above output is visible, the described problem does
not show up.
Upstream-ID: a87b0fd4f9003f8521226e226cf92b18147b3519
745f5d20e7936931f924410f32d8b0e599b5990e
Problem-ID: 196017
Preventive: yes
Reported: Christian Rund <[email protected]>
SupportTicket: -
Reference: -
Date: 2022-01-20
Author: Thomas Richter <[email protected]>
Component: kernel
** Affects: linux (Ubuntu)
Importance: Undecided
Assignee: Skipper Bug Screeners (skipper-screen-team)
Status: New
** Tags: architecture-s39064 bugnameltc-196340 severity-high
targetmilestone-inin---
** Tags added: architecture-s39064 bugnameltc-196340 severity-high
targetmilestone-inin---
** Changed in: ubuntu
Assignee: (unassigned) => Skipper Bug Screeners (skipper-screen-team)
** Package changed: ubuntu => linux (Ubuntu)
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https://bugs.launchpad.net/bugs/1960182
Title:
[UBUNTU 20.04] kernel: Add support for CPU-MF counter second version 7
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