aboutsummaryrefslogtreecommitdiffstats
path: root/tools/testing/selftests/powerpc/include
diff options
context:
space:
mode:
authorMichael Ellerman <mpe@ellerman.id.au>2019-05-20 20:55:20 +1000
committerMichael Ellerman <mpe@ellerman.id.au>2019-10-30 15:43:57 +1100
commitc790c3d2b0ec5979d83451d0688d1cd07e23d8ba (patch)
tree7477bac3de08b16bff9472adc4d29bac822c5818 /tools/testing/selftests/powerpc/include
parentselftests/powerpc: Fixup clobbers for TM tests (diff)
downloadlinux-dev-c790c3d2b0ec5979d83451d0688d1cd07e23d8ba.tar.xz
linux-dev-c790c3d2b0ec5979d83451d0688d1cd07e23d8ba.zip
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.h1
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);