migration: Use MigrationStatus instead of int

QEMU uses "int" in most cases even if it stores MigrationStatus.  I don't
know why, so let's try to do that right and see what blows up..

Reviewed-by: Fabiano Rosas <farosas@suse.de>
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Fabiano Rosas <farosas@suse.de>
diff --git a/migration/migration.c b/migration/migration.c
index f9b69af..795b30f 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -413,7 +413,7 @@
     yank_unregister_instance(MIGRATION_YANK_INSTANCE);
 }
 
-static void migrate_generate_event(int new_state)
+static void migrate_generate_event(MigrationStatus new_state)
 {
     if (migrate_events()) {
         qapi_event_send_migration(new_state);
@@ -1296,8 +1296,6 @@
     }
 
     switch (mis->state) {
-    case MIGRATION_STATUS_NONE:
-        return;
     case MIGRATION_STATUS_SETUP:
     case MIGRATION_STATUS_CANCELLING:
     case MIGRATION_STATUS_CANCELLED:
@@ -1313,6 +1311,8 @@
         info->has_status = true;
         fill_destination_postcopy_migration_info(info);
         break;
+    default:
+        return;
     }
     info->status = mis->state;
 
@@ -1360,7 +1360,8 @@
 
 /* shared migration helpers */
 
-void migrate_set_state(int *state, int old_state, int new_state)
+void migrate_set_state(MigrationStatus *state, MigrationStatus old_state,
+                       MigrationStatus new_state)
 {
     assert(new_state < MIGRATION_STATUS__MAX);
     if (qatomic_cmpxchg(state, old_state, new_state) == old_state) {
@@ -1567,7 +1568,7 @@
     }
 }
 
-bool migration_postcopy_is_alive(int state)
+bool migration_postcopy_is_alive(MigrationStatus state)
 {
     switch (state) {
     case MIGRATION_STATUS_POSTCOPY_ACTIVE:
@@ -1612,20 +1613,9 @@
     case MIGRATION_STATUS_COMPLETED:
     case MIGRATION_STATUS_FAILED:
         return true;
-    case MIGRATION_STATUS_SETUP:
-    case MIGRATION_STATUS_CANCELLING:
-    case MIGRATION_STATUS_ACTIVE:
-    case MIGRATION_STATUS_POSTCOPY_ACTIVE:
-    case MIGRATION_STATUS_COLO:
-    case MIGRATION_STATUS_PRE_SWITCHOVER:
-    case MIGRATION_STATUS_DEVICE:
-    case MIGRATION_STATUS_WAIT_UNPLUG:
+    default:
         return false;
-    case MIGRATION_STATUS__MAX:
-        g_assert_not_reached();
     }
-
-    return false;
 }
 
 bool migration_is_active(void)
diff --git a/migration/migration.h b/migration/migration.h
index 6af0136..38aa140 100644
--- a/migration/migration.h
+++ b/migration/migration.h
@@ -160,7 +160,7 @@
     /* PostCopyFD's for external userfaultfds & handlers of shared memory */
     GArray   *postcopy_remote_fds;
 
-    int state;
+    MigrationStatus state;
 
     /*
      * The incoming migration coroutine, non-NULL during qemu_loadvm_state().
@@ -301,7 +301,7 @@
     /* params from 'migrate-set-parameters' */
     MigrationParameters parameters;
 
-    int state;
+    MigrationStatus state;
 
     /* State related to return path */
     struct {
@@ -459,7 +459,8 @@
     bool rdma_migration;
 };
 
-void migrate_set_state(int *state, int old_state, int new_state);
+void migrate_set_state(MigrationStatus *state, MigrationStatus old_state,
+                       MigrationStatus new_state);
 
 void migration_fd_process_incoming(QEMUFile *f);
 void migration_ioc_process_incoming(QIOChannel *ioc, Error **errp);
@@ -479,7 +480,7 @@
 bool migration_is_blocked(Error **errp);
 /* True if outgoing migration has entered postcopy phase */
 bool migration_in_postcopy(void);
-bool migration_postcopy_is_alive(int state);
+bool migration_postcopy_is_alive(MigrationStatus state);
 MigrationState *migrate_get_current(void);
 bool migration_has_failed(MigrationState *);
 bool migrate_mode_is_cpr(MigrationState *);