[v3,0/5] KVM: selftests: access_tracking_perf_test fixes for NUMA balancing and MGLRU

Message

James Houghton April 14, 2025, 8:09 p.m. UTC

This series fixes some issues with access_tracking_perf_test when MGLRU
or NUMA balancing are in use.

With MGLRU, touching a page doesn't necessarily clear the Idle flag.
This has come up in the past, and the recommendation was to use MGLRU
generation numbers[1], which this series does.

With NUMA balancing, pages are temporarily mapped as PROT_NONE, so the
SPTEs will be zapped, losing the Accessed bits. The fix here is, in the
event we have lost access information to print a warning and continue
with the test, just like what we do if the test is running a nested VM.

A flag is added for the user to specify if they wish for the test to
always enforce or always skip this check.

Based on kvm/next.

Changelog:

v2[3] -> v3:
- Applied David's directory fix on patch 3.
- Added SoB-by, R-by (patch 2, missed in v2), and A-by.

v1[2] -> v2:
- Re-add clone3_selftests.h for cgroup selftests (thanks Michal!)
- Some comment fixes, patches 2 and 5 (thanks Maxim!).

[1]: https://lore.kernel.org/all/CAOUHufZeADNp_y=Ng+acmMMgnTR=ZGFZ7z-m6O47O=[e-mail]/
[2]: https://lore.kernel.org/kvm/[e-mail]/
[3]: https://lore.kernel.org/kvm/[e-mail]/

James Houghton (3):
  cgroup: selftests: Move cgroup_util into its own library
  KVM: selftests: Build and link selftests/cgroup/lib into KVM selftests
  KVM: selftests: access_tracking_perf_test: Use MGLRU for access
    tracking

Maxim Levitsky (1):
  KVM: selftests: access_tracking_perf_test: Add option to skip the
    sanity check

Sean Christopherson (1):
  KVM: selftests: Extract guts of THP accessor to standalone sysfs
    helpers

 tools/testing/selftests/cgroup/Makefile       |  21 +-
 .../selftests/cgroup/{ => lib}/cgroup_util.c  |   2 +-
 .../cgroup/{ => lib/include}/cgroup_util.h    |   4 +-
 .../testing/selftests/cgroup/lib/libcgroup.mk |  19 +
 tools/testing/selftests/kvm/Makefile.kvm      |   4 +-
 .../selftests/kvm/access_tracking_perf_test.c | 263 ++++++++++--
 .../selftests/kvm/include/lru_gen_util.h      |  51 +++
 .../testing/selftests/kvm/include/test_util.h |   1 +
 .../testing/selftests/kvm/lib/lru_gen_util.c  | 383 ++++++++++++++++++
 tools/testing/selftests/kvm/lib/test_util.c   |  42 +-
 10 files changed, 733 insertions(+), 57 deletions(-)
 rename tools/testing/selftests/cgroup/{ => lib}/cgroup_util.c (99%)
 rename tools/testing/selftests/cgroup/{ => lib/include}/cgroup_util.h (99%)
 create mode 100644 tools/testing/selftests/cgroup/lib/libcgroup.mk
 create mode 100644 tools/testing/selftests/kvm/include/lru_gen_util.h
 create mode 100644 tools/testing/selftests/kvm/lib/lru_gen_util.c


base-commit: fd02aa45bda6d2f2fedcab70e828867332ef7e1c