Commit 48236960 authored by Babu Moger's avatar Babu Moger Committed by Shuah Khan
Browse files

selftests/resctrl: Fix non-contiguous CBM for AMD 



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: ae638551 ("selftests/resctrl: Add non-contiguous CBMs CAT test")
Signed-off-by: default avatarBabu Moger <babu.moger@amd.com>
Reviewed-by: default avatarReinette Chatre <reinette.chatre@intel.com>
Reviewed-by: default avatarIlpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: default avatarShuah Khan <skhan@linuxfoundation.org>
parent ed3994ac

tools/testing/selftests/resctrl/cat_test.c

+22 −10
Original line number Diff line number Diff line
@@ -291,11 +291,30 @@ 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];
@@ -304,15 +323,8 @@ 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;

	}