diff --git a/include/runtime_services/ffa_helpers.h b/include/runtime_services/ffa_helpers.h
index 1774848..6d9c61d 100644
--- a/include/runtime_services/ffa_helpers.h
+++ b/include/runtime_services/ffa_helpers.h
@@ -30,6 +30,21 @@
 #include <cassert.h>
 #include <stdint.h>
 
+/**
+ * FF-A Feature ID, to be used with interface FFA_FEATURES.
+ * As defined in the FF-A v1.1 Beta specification, table 13.10, in section
+ * 13.2.
+ */
+
+/** Query interrupt ID of Notification Pending Interrupt. */
+#define FFA_FEATURE_NPI 0x1U
+
+/** Query interrupt ID of Schedule Receiver Interrupt. */
+#define FFA_FEATURE_SRI 0x2U
+
+/** Query interrupt ID of the Managed Exit Interrupt. */
+#define FFA_FEATURE_MEI 0x3U
+
 /** Partition property: partition supports receipt of direct requests. */
 #define FFA_PARTITION_DIRECT_REQ_RECV 0x1
 
@@ -62,6 +77,11 @@
 	return (ffa_id_t) val.ret2 & 0xffff;
 }
 
+static inline uint32_t ffa_feature_intid(smc_ret_values val)
+{
+	return (uint32_t)val.ret2;
+}
+
 typedef uint64_t ffa_notification_bitmap_t;
 
 #define FFA_NOTIFICATION(ID)		(UINT64_C(1) << ID)