pmu-mem-access in ubuntu_kvm_unit_tests failed with B-4.15 ARM64

[Po-Hsu Lin]

Issue found on 4.15.0-157.164 with ARM64 node appleton-kernel

Test failed with:
 FAIL: pmu: pmu-mem-access: Ran 20 mem accesses
 FAIL: pmu: pmu-mem-access: Ran 20 mem accesses with expected overflows on both counters

Test log:
Running '/home/ubuntu/autotest/client/tmp/ubuntu_kvm_unit_tests/src/kvm-unit-tests/tests/pmu-mem-access'
 BUILD_HEAD=1593e88a
 timeout -k 1s --foreground 90s /usr/bin/qemu-system-aarch64 -nodefaults -machine virt,gic-version=host,accel=kvm -cpu host -device virtio-serial-device -device virtconsole,chardev=ctd -chardev testdev,id=ctd -device pci-testdev -display none -serial stdio -kernel /tmp/tmp.sBnT4OlWX6 -smp 1 -append pmu-mem-access # -initrd /tmp/tmp.CAKgBfctJh
 INFO: PMU version: 0x1
 INFO: PMU implementer/ID code: 0x41("A")/0x2
 INFO: Implements 6 event counters
 INFO: pmu: pmu-mem-access: counter #0 is 1460 (MEM_ACCESS)
 INFO: pmu: pmu-mem-access: counter #1 is 1386 (MEM_ACCESS)
 FAIL: pmu: pmu-mem-access: Ran 20 mem accesses
 FAIL: pmu: pmu-mem-access: Ran 20 mem accesses with expected overflows on both counters
 INFO: pmu: pmu-mem-access: cnt#0 = 1432 cnt#1=1364 overflow=0x0
 SUMMARY: 2 tests, 2 unexpected failures
 FAIL pmu-mem-access (2 tests, 2 unexpected failures)

This issue can be found with 4.15.0-154.161 as well. Not a regression.

[Po-Hsu Lin (cypressyew)]

With kvm-unit-test repo updated to d8a4f9e5 (ci: Update the list of tests that we run in the Fedora Cirrus-CI), this test is still failing with the same error message.