add more helper functions with explicit milli/nanosecond resolution

The code doesn't make much sense right now, but it will as
soon as timers will be able to scale their resolution arbitrarily.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

qemu-timer.h

@@ -12,6 +12,10 @@
 
 /* timers */
 
+#define SCALE_MS 1000000
+#define SCALE_US 1000
+#define SCALE_NS 1
+
 typedef struct QEMUClock QEMUClock;
 typedef void QEMUTimerCB(void *opaque);
 
@@ -54,6 +58,25 @@ void init_clocks(void);
 int init_timer_alarm(void);
 void quit_timers(void);
 
+static inline QEMUTimer *qemu_new_timer_ns(QEMUClock *clock, QEMUTimerCB *cb,
+                                           void *opaque)
+{
+    assert(clock != rt_clock);
+    return qemu_new_timer(clock, cb, opaque);
+}
+
+static inline QEMUTimer *qemu_new_timer_ms(QEMUClock *clock, QEMUTimerCB *cb,
+                                           void *opaque)
+{
+    assert(clock == rt_clock);
+    return qemu_new_timer(clock, cb, opaque);
+}
+
+static inline int64_t qemu_get_clock_ms(QEMUClock *clock)
+{
+    return qemu_get_clock_ns(clock) / SCALE_MS;
+}
+
 static inline int64_t get_ticks_per_sec(void)
 {
     return 1000000000LL;