6.9-stable review patch. If anyone has any objections, please let me know.
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From: Babu Moger babu.moger@amd.com
[ Upstream commit 48236960c06d32370bfa6f2cc408e786873262c8 ]
The non-contiguous CBM test fails on AMD with: Starting L3_NONCONT_CAT test ... Mounting resctrl to "/sys/fs/resctrl" CPUID output doesn't match 'sparse_masks' file content! not ok 5 L3_NONCONT_CAT: test
AMD always supports non-contiguous CBM but does not report it via CPUID.
Fix the non-contiguous CBM test to use CPUID to discover non-contiguous CBM support only on Intel.
Fixes: ae638551ab64 ("selftests/resctrl: Add non-contiguous CBMs CAT test") Signed-off-by: Babu Moger babu.moger@amd.com Reviewed-by: Reinette Chatre reinette.chatre@intel.com Reviewed-by: Ilpo Järvinen ilpo.jarvinen@linux.intel.com Signed-off-by: Shuah Khan skhan@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- tools/testing/selftests/resctrl/cat_test.c | 32 +++++++++++++++------- 1 file changed, 22 insertions(+), 10 deletions(-)
diff --git a/tools/testing/selftests/resctrl/cat_test.c b/tools/testing/selftests/resctrl/cat_test.c index 4cb991be8e31b..178a41d4bb1be 100644 --- a/tools/testing/selftests/resctrl/cat_test.c +++ b/tools/testing/selftests/resctrl/cat_test.c @@ -294,11 +294,30 @@ static int cat_run_test(const struct resctrl_test *test, const struct user_param return ret; }
+static bool arch_supports_noncont_cat(const struct resctrl_test *test) +{ + unsigned int eax, ebx, ecx, edx; + + /* AMD always supports non-contiguous CBM. */ + if (get_vendor() == ARCH_AMD) + return true; + + /* Intel support for non-contiguous CBM needs to be discovered. */ + if (!strcmp(test->resource, "L3")) + __cpuid_count(0x10, 1, eax, ebx, ecx, edx); + else if (!strcmp(test->resource, "L2")) + __cpuid_count(0x10, 2, eax, ebx, ecx, edx); + else + return false; + + return ((ecx >> 3) & 1); +} + static int noncont_cat_run_test(const struct resctrl_test *test, const struct user_params *uparams) { unsigned long full_cache_mask, cont_mask, noncont_mask; - unsigned int eax, ebx, ecx, edx, sparse_masks; + unsigned int sparse_masks; int bit_center, ret; char schemata[64];
@@ -307,15 +326,8 @@ static int noncont_cat_run_test(const struct resctrl_test *test, if (ret) return ret;
- if (!strcmp(test->resource, "L3")) - __cpuid_count(0x10, 1, eax, ebx, ecx, edx); - else if (!strcmp(test->resource, "L2")) - __cpuid_count(0x10, 2, eax, ebx, ecx, edx); - else - return -EINVAL; - - if (sparse_masks != ((ecx >> 3) & 1)) { - ksft_print_msg("CPUID output doesn't match 'sparse_masks' file content!\n"); + if (arch_supports_noncont_cat(test) != sparse_masks) { + ksft_print_msg("Hardware and kernel differ on non-contiguous CBM support!\n"); return 1; }