test(interrupts): hint fwd destination SP could be interrupted

TFTF can send a hint to the destination SP to expect that the
forwarded sleep command could be preempted by a non-secure interrupt.

This can make the tests exercising SP's response to non-secure
interrupt robust by allowing the destination SP to check if the
forward destination SP has indeed been preempted.

Signed-off-by: Madhukar Pappireddy <madhukar.pappireddy@arm.com>
Change-Id: I808ee6c63687438d0092a53389f11bf9b3dd532d
diff --git a/spm/cactus/cactus_tests/cactus_test_interrupts.c b/spm/cactus/cactus_tests/cactus_test_interrupts.c
index 13a5e59..c438050 100644
--- a/spm/cactus/cactus_tests/cactus_test_interrupts.c
+++ b/spm/cactus/cactus_tests/cactus_test_interrupts.c
@@ -48,6 +48,8 @@
 	ffa_id_t vm_id = ffa_dir_msg_dest(*args);
 	ffa_id_t fwd_dest = cactus_get_fwd_sleep_dest(*args);
 	uint32_t sleep_ms = cactus_get_sleep_time(*args);
+	bool hint_interrupted = cactus_get_fwd_sleep_interrupted_hint(*args);
+	bool fwd_dest_interrupted;
 
 	VERBOSE("VM%x requested %x to sleep for value %u\n",
 		ffa_dir_msg_source(*args), fwd_dest, sleep_ms);
@@ -62,6 +64,7 @@
 	while ((ffa_func_id(ffa_ret) == FFA_INTERRUPT) ||
 		is_expected_cactus_response(ffa_ret, MANAGED_EXIT_INTERRUPT_ID,
 					    0)) {
+		fwd_dest_interrupted = true;
 
 		if (ffa_func_id(ffa_ret) == FFA_INTERRUPT) {
 			/* Received FFA_INTERRUPT in blocked state. */
@@ -84,6 +87,13 @@
 		}
 	}
 
+	if (hint_interrupted && !fwd_dest_interrupted) {
+		ERROR("Forwaded destination of the sleep command was not"
+		      " interrupted as anticipated\n");
+		return cactus_error_resp(vm_id, ffa_dir_msg_source(*args),
+					 CACTUS_ERROR_TEST);
+	}
+
 	if (!is_ffa_direct_response(ffa_ret)) {
 		ERROR("Encountered error in CACTUS_FWD_SLEEP_CMD response\n");
 		return cactus_error_resp(vm_id, ffa_dir_msg_source(*args),