diff --git a/tools/testing/selftests/resctrl/cmt_test.c b/tools/testing/selftests/resctrl/cmt_test.c
index d09e693dc739..7bc6cf49c1c5 100644
--- a/tools/testing/selftests/resctrl/cmt_test.c
+++ b/tools/testing/selftests/resctrl/cmt_test.c
@@ -19,12 +19,34 @@
 #define CON_MON_LCC_OCCUP_PATH		\
 	"%s/%s/mon_data/mon_L3_%02d/llc_occupancy"
 
-static int cmt_init(const struct resctrl_val_param *param, int domain_id)
+/*
+ * Initialize capacity bitmasks (CBMs) of:
+ * - control group being tested per test parameters,
+ * - default resource group as inverse of control group being tested to prevent
+ *   other tasks from interfering with test.
+ */
+static int cmt_init(const struct resctrl_test *test,
+		    const struct user_params *uparams,
+		    const struct resctrl_val_param *param, int domain_id)
 {
+	unsigned long full_mask;
+	char schemata[64];
+	int ret;
+
 	sprintf(llc_occup_path, CON_MON_LCC_OCCUP_PATH, RESCTRL_PATH,
 		param->ctrlgrp, domain_id);
 
-	return 0;
+	ret = get_full_cbm(test->resource, &full_mask);
+	if (ret)
+		return ret;
+
+	snprintf(schemata, sizeof(schemata), "%lx", ~param->mask & full_mask);
+	ret = write_schemata("", schemata, uparams->cpu, test->resource);
+	if (ret)
+		return ret;
+
+	snprintf(schemata, sizeof(schemata), "%lx", param->mask);
+	return write_schemata(param->ctrlgrp, schemata, uparams->cpu, test->resource);
 }
 
 static int cmt_setup(const struct resctrl_test *test,
diff --git a/tools/testing/selftests/resctrl/mba_test.c b/tools/testing/selftests/resctrl/mba_test.c
index c7e9adc0368f..cd4c715b7ffd 100644
--- a/tools/testing/selftests/resctrl/mba_test.c
+++ b/tools/testing/selftests/resctrl/mba_test.c
@@ -17,7 +17,9 @@
 #define ALLOCATION_MIN		10
 #define ALLOCATION_STEP		10
 
-static int mba_init(const struct resctrl_val_param *param, int domain_id)
+static int mba_init(const struct resctrl_test *test,
+		    const struct user_params *uparams,
+		    const struct resctrl_val_param *param, int domain_id)
 {
 	int ret;
 
diff --git a/tools/testing/selftests/resctrl/mbm_test.c b/tools/testing/selftests/resctrl/mbm_test.c
index 84d8bc250539..58201f844740 100644
--- a/tools/testing/selftests/resctrl/mbm_test.c
+++ b/tools/testing/selftests/resctrl/mbm_test.c
@@ -83,7 +83,9 @@ static int check_results(size_t span)
 	return ret;
 }
 
-static int mbm_init(const struct resctrl_val_param *param, int domain_id)
+static int mbm_init(const struct resctrl_test *test,
+		    const struct user_params *uparams,
+		    const struct resctrl_val_param *param, int domain_id)
 {
 	int ret;
 
diff --git a/tools/testing/selftests/resctrl/resctrl.h b/tools/testing/selftests/resctrl/resctrl.h
index afe635b6e48d..c72045c74ac4 100644
--- a/tools/testing/selftests/resctrl/resctrl.h
+++ b/tools/testing/selftests/resctrl/resctrl.h
@@ -135,7 +135,9 @@ struct resctrl_val_param {
 	char			filename[64];
 	unsigned long		mask;
 	int			num_of_runs;
-	int			(*init)(const struct resctrl_val_param *param,
+	int			(*init)(const struct resctrl_test *test,
+					const struct user_params *uparams,
+					const struct resctrl_val_param *param,
 					int domain_id);
 	int			(*setup)(const struct resctrl_test *test,
 					 const struct user_params *uparams,
diff --git a/tools/testing/selftests/resctrl/resctrl_val.c b/tools/testing/selftests/resctrl/resctrl_val.c
index 7c08e936572d..a5a8badb83d4 100644
--- a/tools/testing/selftests/resctrl/resctrl_val.c
+++ b/tools/testing/selftests/resctrl/resctrl_val.c
@@ -569,7 +569,7 @@ int resctrl_val(const struct resctrl_test *test,
 		goto reset_affinity;
 
 	if (param->init) {
-		ret = param->init(param, domain_id);
+		ret = param->init(test, uparams, param, domain_id);
 		if (ret)
 			goto reset_affinity;
 	}