qemu: Adjust qemu wakeup

Currently Xen hvm s3 has a bug coming from the difference between
qemu-traditioanl and qemu-xen. For qemu-traditional, the way to
resume from hvm s3 is via 'xl trigger' command. However, for
qemu-xen, the way to resume from hvm s3 inherited from standard
qemu, i.e. via QMP, and it doesn't work under Xen.

The root cause is, for qemu-xen, 'xl trigger' command didn't reset
devices, while QMP didn't unpause hvm domain though they did qemu
system reset.

We have two qemu patches and one xl patch to fix Xen hvm s3 bug.
This patch is the qemu patch 1. It adjusts qemu wakeup so that
Xen s3 resume logic (which will be implemented at qemu patch 2)
will be notified after qemu system reset.
Signed-off-by: NLiu Jinsong <jinsong.liu@intel.com>
Signed-off-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NAnthony PERARD <anthony.perard@citrix.com>

hw/acpi/core.c

@@ -324,12 +324,13 @@ static void acpi_notify_wakeup(Notifier *notifier, void *data)
             (ACPI_BITMASK_WAKE_STATUS | ACPI_BITMASK_TIMER_STATUS);
         break;
     case QEMU_WAKEUP_REASON_OTHER:
-    default:
         /* ACPI_BITMASK_WAKE_STATUS should be set on resume.
            Pretend that resume was caused by power button */
         ar->pm1.evt.sts |=
             (ACPI_BITMASK_WAKE_STATUS | ACPI_BITMASK_POWER_BUTTON_STATUS);
         break;
+    default:
+        break;
     }
 }
 

include/sysemu/sysemu.h

@@ -41,9 +41,11 @@ int vm_stop(RunState state);
 int vm_stop_force_state(RunState state);
 
 typedef enum WakeupReason {
-    QEMU_WAKEUP_REASON_OTHER = 0,
+    /* Always keep QEMU_WAKEUP_REASON_NONE = 0 */
+    QEMU_WAKEUP_REASON_NONE = 0,
     QEMU_WAKEUP_REASON_RTC,
     QEMU_WAKEUP_REASON_PMTIMER,
+    QEMU_WAKEUP_REASON_OTHER,
 } WakeupReason;
 
 void qemu_system_reset_request(void);

vl.c

@@ -1718,14 +1718,14 @@ static pid_t shutdown_pid;
 static int powerdown_requested;
 static int debug_requested;
 static int suspend_requested;
-static int wakeup_requested;
+static WakeupReason wakeup_reason;
 static NotifierList powerdown_notifiers =
     NOTIFIER_LIST_INITIALIZER(powerdown_notifiers);
 static NotifierList suspend_notifiers =
     NOTIFIER_LIST_INITIALIZER(suspend_notifiers);
 static NotifierList wakeup_notifiers =
     NOTIFIER_LIST_INITIALIZER(wakeup_notifiers);
-static uint32_t wakeup_reason_mask = ~0;
+static uint32_t wakeup_reason_mask = ~(1 << QEMU_WAKEUP_REASON_NONE);
 static RunState vmstop_requested = RUN_STATE_MAX;
 
 int qemu_shutdown_requested_get(void)
@@ -1775,11 +1775,9 @@ static int qemu_suspend_requested(void)
     return r;
 }
 
-static int qemu_wakeup_requested(void)
+static WakeupReason qemu_wakeup_requested(void)
 {
-    int r = wakeup_requested;
-    wakeup_requested = 0;
-    return r;
+    return wakeup_reason;
 }
 
 static int qemu_powerdown_requested(void)
@@ -1896,8 +1894,7 @@ void qemu_system_wakeup_request(WakeupReason reason)
         return;
     }
     runstate_set(RUN_STATE_RUNNING);
-    notifier_list_notify(&wakeup_notifiers, &reason);
-    wakeup_requested = 1;
+    wakeup_reason = reason;
     qemu_notify_event();
 }
 
@@ -1989,6 +1986,8 @@ static bool main_loop_should_exit(void)
         pause_all_vcpus();
         cpu_synchronize_all_states();
         qemu_system_reset(VMRESET_SILENT);
+        notifier_list_notify(&wakeup_notifiers, &wakeup_reason);
+        wakeup_reason = QEMU_WAKEUP_REASON_NONE;
         resume_all_vcpus();
         monitor_protocol_event(QEVENT_WAKEUP, NULL);
     }