aio / timers: Use all timerlists in icount warp calculations

Notify all timerlists derived from vm_clock in icount warp
calculations.

When calculating timer delay based on vm_clock deadline, use
all timerlists.

For compatibility, maintain an apparent bug where when using
icount, if no vm_clock timer was set, qemu_clock_deadline
would return INT32_MAX and always set an icount clock expiry
about 2 seconds ahead.

NB: thread safety - when different timerlists sit on different
threads, this will need some locking.

Signed-off-by: Alex Bligh <alex@alex.org.uk>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
diff --git a/qemu-timer.c b/qemu-timer.c
index 746ba8b..b56bfde 100644
--- a/qemu-timer.c
+++ b/qemu-timer.c
@@ -392,6 +392,22 @@
     return timerlist_deadline_ns(clock->main_loop_timerlist);
 }
 
+/* Calculate the soonest deadline across all timerlists attached
+ * to the clock. This is used for the icount timeout so we
+ * ignore whether or not the clock should be used in deadline
+ * calculations.
+ */
+int64_t qemu_clock_deadline_ns_all(QEMUClock *clock)
+{
+    int64_t deadline = -1;
+    QEMUTimerList *timer_list;
+    QLIST_FOREACH(timer_list, &clock->timerlists, list) {
+        deadline = qemu_soonest_timeout(deadline,
+                                        timerlist_deadline_ns(timer_list));
+    }
+    return deadline;
+}
+
 QEMUClock *timerlist_get_clock(QEMUTimerList *timer_list)
 {
     return timer_list->clock;