suspend: make rtc alarm wakeup the guest.

Make the rtc wake up the guest when the alarm fires.
Add acpi windup to property support RTC_EN, so guests
can enable and disable this.
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

hw/acpi.c

@@ -254,6 +254,10 @@ static void acpi_notify_wakeup(Notifier *notifier, void *data)
     WakeupReason *reason = data;
 
     switch (*reason) {
+    case QEMU_WAKEUP_REASON_RTC:
+        ar->pm1.evt.sts |=
+            (ACPI_BITMASK_WAKE_STATUS | ACPI_BITMASK_RT_CLOCK_STATUS);
+        break;
     case QEMU_WAKEUP_REASON_OTHER:
     default:
         /* ACPI_BITMASK_WAKE_STATUS should be set on resume.
@@ -287,6 +291,8 @@ void acpi_pm1_evt_write_sts(ACPIREGS *ar, uint16_t val)
 void acpi_pm1_evt_write_en(ACPIREGS *ar, uint16_t val)
 {
     ar->pm1.evt.en = val;
+    qemu_system_wakeup_enable(QEMU_WAKEUP_REASON_RTC,
+                              val & ACPI_BITMASK_RT_CLOCK_ENABLE);
 }
 
 void acpi_pm1_evt_power_down(ACPIREGS *ar)
@@ -301,6 +307,7 @@ void acpi_pm1_evt_reset(ACPIREGS *ar)
 {
     ar->pm1.evt.sts = 0;
     ar->pm1.evt.en = 0;
+    qemu_system_wakeup_enable(QEMU_WAKEUP_REASON_RTC, 0);
 }
 
 /* ACPI PM_TMR */

hw/mc146818rtc.c

@@ -437,6 +437,7 @@ static void rtc_update_second2(void *opaque)
 
         s->cmos_data[RTC_REG_C] |= REG_C_AF;
         if (s->cmos_data[RTC_REG_B] & REG_B_AIE) {
+            qemu_system_wakeup_request(QEMU_WAKEUP_REASON_RTC);
             qemu_irq_raise(s->irq);
             s->cmos_data[RTC_REG_C] |= REG_C_IRQF;
         }

sysemu.h

@@ -40,6 +40,7 @@ void vm_stop_force_state(RunState state);
 
 typedef enum WakeupReason {
     QEMU_WAKEUP_REASON_OTHER = 0,
+    QEMU_WAKEUP_REASON_RTC,
 } WakeupReason;
 
 void qemu_system_reset_request(void);