diff --git a/spm/cactus/cactus_tests/cactus_message_loop.c b/spm/cactus/cactus_tests/cactus_message_loop.c
index e56e51e..c0abf2b 100644
--- a/spm/cactus/cactus_tests/cactus_message_loop.c
+++ b/spm/cactus/cactus_tests/cactus_message_loop.c
@@ -11,6 +11,7 @@
 #include <ffa_helpers.h>
 #include <events.h>
 #include <platform.h>
+#include <spm_helpers.h>
 
 /**
  * Counter of the number of handled requests, for each CPU. The number of
@@ -43,9 +44,8 @@
 {
 	uint64_t in_cmd;
 
-	/* Get which core it is running from. */
-	unsigned int core_pos = platform_get_core_pos(
-						read_mpidr_el1() & MPID_MASK);
+	/* Get vCPU index for currently running vCPU. */
+	unsigned int core_pos = spm_get_my_core_pos();
 
 	if (cmd_args == NULL || ret == NULL) {
 		ERROR("Invalid arguments passed to %s!\n", __func__);
diff --git a/spm/cactus/cactus_tests/cactus_test_interrupts.c b/spm/cactus/cactus_tests/cactus_test_interrupts.c
index 4250445..2e0249c 100644
--- a/spm/cactus/cactus_tests/cactus_test_interrupts.c
+++ b/spm/cactus/cactus_tests/cactus_test_interrupts.c
@@ -86,8 +86,9 @@
 			/* Received FFA_INTERRUPT in blocked state. */
 			VERBOSE("Processing FFA_INTERRUPT while"
 				" blocked on direct response\n");
-			unsigned int my_core_pos =
-				platform_get_core_pos(read_mpidr_el1());
+
+			/* Get vCPU index for currently running vCPU. */
+			unsigned int my_core_pos = spm_get_my_core_pos();
 
 			ffa_ret = ffa_run(fwd_dest, my_core_pos);
 		} else {
diff --git a/spm/cactus/cactus_tests/cactus_test_notifications.c b/spm/cactus/cactus_tests/cactus_test_notifications.c
index d8b88ed..6d7b41b 100644
--- a/spm/cactus/cactus_tests/cactus_test_notifications.c
+++ b/spm/cactus/cactus_tests/cactus_test_notifications.c
@@ -9,6 +9,7 @@
 #include "sp_tests.h"
 
 #include <ffa_helpers.h>
+#include <spm_helpers.h>
 #include <debug.h>
 
 /* Booleans to keep track of which CPUs handled NPI. */
@@ -33,9 +34,8 @@
 
 void notification_pending_interrupt_handler(void)
 {
-	/* Get which core it is running from. */
-	unsigned int core_pos = platform_get_core_pos(
-						read_mpidr_el1() & MPID_MASK);
+	/* Get vCPU index for currently running vCPU. */
+	unsigned int core_pos = spm_get_my_core_pos();
 
 	VERBOSE("NPI handled in core %u\n", core_pos);
 
diff --git a/spm/cactus/cactus_tests/cactus_test_simd.c b/spm/cactus/cactus_tests/cactus_test_simd.c
index a1366d3..bcf1c38 100644
--- a/spm/cactus/cactus_tests/cactus_test_simd.c
+++ b/spm/cactus/cactus_tests/cactus_test_simd.c
@@ -7,6 +7,7 @@
 #include "cactus_message_loop.h"
 #include "cactus_test_cmds.h"
 #include <fpu.h>
+#include <spm_helpers.h>
 #include "spm_common.h"
 
 /*
@@ -21,7 +22,8 @@
  */
 CACTUS_CMD_HANDLER(req_simd_fill, CACTUS_REQ_SIMD_FILL_CMD)
 {
-	core_pos = platform_get_core_pos(read_mpidr_el1());
+	/* Get vCPU index for currently running vCPU. */
+	core_pos = spm_get_my_core_pos();
 	fpu_state_write_rand(&sp_fpu_state_write);
 	return cactus_response(ffa_dir_msg_dest(*args),
 			       ffa_dir_msg_source(*args),
@@ -36,7 +38,8 @@
 {
 	bool test_succeed = false;
 
-	unsigned int core_pos1 = platform_get_core_pos(read_mpidr_el1());
+	/* Get vCPU index for currently running vCPU. */
+	unsigned int core_pos1 = spm_get_my_core_pos();
 	if (core_pos1 == core_pos) {
 		fpu_state_read(&sp_fpu_state_read);
 		if (fpu_state_compare(&sp_fpu_state_write,
diff --git a/spm/common/spm_helpers.c b/spm/common/spm_helpers.c
index 1cb5f4d..b2a4709 100644
--- a/spm/common/spm_helpers.c
+++ b/spm/common/spm_helpers.c
@@ -56,3 +56,16 @@
 
 	return (int64_t)ret.ret0;
 }
+
+/**
+ * Return vCPU index for the currently running vCPU.
+ * Virtual MPIDR holds the linear vCPU index information in lower bits.
+ * Keep only first 24 bits (mapping to Aff0/Aff1/Aff2).
+ * Omit Aff3, bit [31], U[30], MT[24].
+ */
+unsigned int spm_get_my_core_pos(void)
+{
+	uint64_t mpidr = read_mpidr_el1();
+
+	return (unsigned int)(mpidr & 0xffffff);
+}
diff --git a/spm/common/spm_helpers.h b/spm/common/spm_helpers.h
index 1d3ddc2..59cdaf1 100644
--- a/spm/common/spm_helpers.h
+++ b/spm/common/spm_helpers.h
@@ -23,4 +23,6 @@
 int64_t spm_interrupt_enable(uint32_t int_id, bool enable, enum interrupt_pin pin);
 int64_t spm_interrupt_deactivate(uint32_t vint_id);
 
+unsigned int spm_get_my_core_pos(void);
+
 #endif /* SPMC_H */