s390x/watchdog: diag288 migration support

Add vmstate structure to keep state and data during migration.

Signed-off-by: Xu Wang <gesaint@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

hw/watchdog/wdt_diag288.c

diff --git a/hw/watchdog/wdt_diag288.c b/hw/watchdog/wdt_diag288.c
index 351b5a8..1185e06 100644
--- a/hw/watchdog/wdt_diag288.c
+++ b/hw/watchdog/wdt_diag288.c
@@ -21,6 +21,17 @@
     .wdt_description = "diag288 device for s390x platform",
 };
 
+static const VMStateDescription vmstate_diag288 = {
+    .name = "vmstate_diag288",
+    .version_id = 0,
+    .minimum_version_id = 0,
+    .fields = (VMStateField[]) {
+        VMSTATE_TIMER_PTR(timer, DIAG288State),
+        VMSTATE_BOOL(enabled, DIAG288State),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
 static void wdt_diag288_reset(DeviceState *dev)
 {
     DIAG288State *diag288 = DIAG288(dev);
@@ -90,6 +101,7 @@
     dc->unrealize = wdt_diag288_unrealize;
     dc->reset = wdt_diag288_reset;
     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
+    dc->vmsd = &vmstate_diag288;
     diag288->handle_timer = wdt_diag288_handle_timer;
 }