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| author | Michael Ellerman <mpe@ellerman.id.au> | 2019-05-20 20:55:20 +1000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2019-10-30 15:43:57 +1100 |
| commit | c790c3d2b0ec5979d83451d0688d1cd07e23d8ba (patch) | |
| tree | 7477bac3de08b16bff9472adc4d29bac822c5818 /tools/testing/selftests/powerpc/include | |
| parent | a02cbc7ffe529ed58b6bbe54652104fc2c88bd77 (diff) | |
selftests/powerpc: Add a test of spectre_v2 mitigations
This test uses the PMU to count branch prediction hits/misses for a
known loop, and compare the result to the reported spectre v2
mitigation.
This gives us a way of sanity checking that the reported mitigation is
actually in effect.
Sample output for some cases, eg:
Power9:
sysfs reports: 'Vulnerable'
PM_BR_PRED_CCACHE: result 368 running/enabled 5792777124
PM_BR_MPRED_CCACHE: result 319 running/enabled 5792775546
PM_BR_PRED_PCACHE: result 2147483281 running/enabled 5792773128
PM_BR_MPRED_PCACHE: result 213604201 running/enabled 5792771640
Miss percent 9 %
OK - Measured branch prediction rates match reported spectre v2 mitigation.
sysfs reports: 'Mitigation: Indirect branch serialisation (kernel only)'
PM_BR_PRED_CCACHE: result 895 running/enabled 5780320920
PM_BR_MPRED_CCACHE: result 822 running/enabled 5780312414
PM_BR_PRED_PCACHE: result 2147482754 running/enabled 5780308836
PM_BR_MPRED_PCACHE: result 213639731 running/enabled 5780307912
Miss percent 9 %
OK - Measured branch prediction rates match reported spectre v2 mitigation.
sysfs reports: 'Mitigation: Indirect branch cache disabled'
PM_BR_PRED_CCACHE: result 2147483649 running/enabled 20540186160
PM_BR_MPRED_CCACHE: result 2147483649 running/enabled 20540180056
PM_BR_PRED_PCACHE: result 0 running/enabled 20540176090
PM_BR_MPRED_PCACHE: result 0 running/enabled 20540174182
Miss percent 100 %
OK - Measured branch prediction rates match reported spectre v2 mitigation.
Power8:
sysfs reports: 'Vulnerable'
PM_BR_PRED_CCACHE: result 2147483649 running/enabled 3505888142
PM_BR_MPRED_CCACHE: result 9 running/enabled 3505882788
Miss percent 0 %
OK - Measured branch prediction rates match reported spectre v2 mitigation.
sysfs reports: 'Mitigation: Indirect branch cache disabled'
PM_BR_PRED_CCACHE: result 2147483649 running/enabled 16931421988
PM_BR_MPRED_CCACHE: result 2147483649 running/enabled 16931416478
Miss percent 100 %
OK - Measured branch prediction rates match reported spectre v2 mitigation.
success: spectre_v2
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190520105520.22274-1-mpe@ellerman.id.au
Diffstat (limited to 'tools/testing/selftests/powerpc/include')
| -rw-r--r-- | tools/testing/selftests/powerpc/include/utils.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/tools/testing/selftests/powerpc/include/utils.h b/tools/testing/selftests/powerpc/include/utils.h index 0e2b2e6284ac..e089a0c30d9a 100644 --- a/tools/testing/selftests/powerpc/include/utils.h +++ b/tools/testing/selftests/powerpc/include/utils.h @@ -34,6 +34,7 @@ int pick_online_cpu(void); int read_debugfs_file(char *debugfs_file, int *result); int write_debugfs_file(char *debugfs_file, int result); +int read_sysfs_file(char *debugfs_file, char *result, size_t result_size); void set_dscr(unsigned long val); int perf_event_open_counter(unsigned int type, unsigned long config, int group_fd); |