diff --git a/hw/irq.c b/hw/irq.c
index 7703f62..db2cce6 100644
--- a/hw/irq.c
+++ b/hw/irq.c
@@ -26,19 +26,27 @@
 
 struct IRQState {
     qemu_irq_handler handler;
+    qemu_irq_fb_handler feedback_handler;
     void *opaque;
     int n;
 };
 
-void qemu_set_irq(qemu_irq irq, int level)
+int qemu_set_irq(qemu_irq irq, int level)
 {
-    if (!irq)
-        return;
-
-    irq->handler(irq->opaque, irq->n, level);
+    if (!irq) {
+        return 0;
+    }
+    if (irq->feedback_handler) {
+        return irq->feedback_handler(irq->opaque, irq->n, level);
+    } else {
+        irq->handler(irq->opaque, irq->n, level);
+        return QEMU_IRQ_DELIVERED;
+    }
 }
 
-qemu_irq *qemu_allocate_irqs(qemu_irq_handler handler, void *opaque, int n)
+static qemu_irq *allocate_irqs(qemu_irq_handler handler,
+                               qemu_irq_fb_handler feedback_handler,
+                               void *opaque, int n)
 {
     qemu_irq *s;
     struct IRQState *p;
@@ -48,6 +56,7 @@ qemu_irq *qemu_allocate_irqs(qemu_irq_handler handler, void *opaque, int n)
     p = (struct IRQState *)qemu_mallocz(sizeof(struct IRQState) * n);
     for (i = 0; i < n; i++) {
         p->handler = handler;
+        p->feedback_handler = feedback_handler;
         p->opaque = opaque;
         p->n = i;
         s[i] = p;
@@ -56,22 +65,33 @@ qemu_irq *qemu_allocate_irqs(qemu_irq_handler handler, void *opaque, int n)
     return s;
 }
 
+qemu_irq *qemu_allocate_irqs(qemu_irq_handler handler, void *opaque, int n)
+{
+    return allocate_irqs(handler, NULL, opaque, n);
+}
+
+qemu_irq *qemu_allocate_feedback_irqs(qemu_irq_fb_handler handler,
+                                      void *opaque, int n)
+{
+    return allocate_irqs(NULL, handler, opaque, n);
+}
+
 void qemu_free_irqs(qemu_irq *s)
 {
     qemu_free(s[0]);
     qemu_free(s);
 }
 
-static void qemu_notirq(void *opaque, int line, int level)
+static int qemu_notirq(void *opaque, int line, int level)
 {
     struct IRQState *irq = opaque;
 
-    irq->handler(irq->opaque, irq->n, !level);
+    return qemu_set_irq(irq, !level);
 }
 
 qemu_irq qemu_irq_invert(qemu_irq irq)
 {
     /* The default state for IRQs is low, so raise the output now.  */
     qemu_irq_raise(irq);
-    return qemu_allocate_irqs(qemu_notirq, irq, 1)[0];
+    return allocate_irqs(NULL, qemu_notirq, irq, 1)[0];
 }
diff --git a/hw/irq.h b/hw/irq.h
index 5daae44..eee03e6 100644
--- a/hw/irq.h
+++ b/hw/irq.h
@@ -3,15 +3,18 @@
 
 /* Generic IRQ/GPIO pin infrastructure.  */
 
-/* FIXME: Rmove one of these.  */
+#define QEMU_IRQ_DELIVERED      0
+#define QEMU_IRQ_COALESCED      (-1)
+#define QEMU_IRQ_MASKED         (-2)
+
 typedef void (*qemu_irq_handler)(void *opaque, int n, int level);
-typedef void SetIRQFunc(void *opaque, int irq_num, int level);
+typedef int (*qemu_irq_fb_handler)(void *opaque, int n, int level);
 
-void qemu_set_irq(qemu_irq irq, int level);
+int qemu_set_irq(qemu_irq irq, int level);
 
-static inline void qemu_irq_raise(qemu_irq irq)
+static inline int qemu_irq_raise(qemu_irq irq)
 {
-    qemu_set_irq(irq, 1);
+    return qemu_set_irq(irq, 1);
 }
 
 static inline void qemu_irq_lower(qemu_irq irq)
@@ -19,14 +22,19 @@ static inline void qemu_irq_lower(qemu_irq irq)
     qemu_set_irq(irq, 0);
 }
 
-static inline void qemu_irq_pulse(qemu_irq irq)
+static inline int qemu_irq_pulse(qemu_irq irq)
 {
-    qemu_set_irq(irq, 1);
+    int ret;
+
+    ret = qemu_set_irq(irq, 1);
     qemu_set_irq(irq, 0);
+    return ret;
 }
 
 /* Returns an array of N IRQs.  */
 qemu_irq *qemu_allocate_irqs(qemu_irq_handler handler, void *opaque, int n);
+qemu_irq *qemu_allocate_feedback_irqs(qemu_irq_fb_handler handler,
+                                      void *opaque, int n);
 void qemu_free_irqs(qemu_irq *s);
 
 /* Returns a new IRQ with opposite polarity.  */