migration: init dst in migration_object_init too

Though we may not need it, now we init both the src/dst migration
objects in migration_object_init() so that even incoming migration
object would be thread safe (it was not).

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20180502104740.12123-20-peterx@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>

1 files changed, 19 insertions, 18 deletions

diff --git a/migration/migration.c b/migration/migration.c
index 240960d951..c1832b0263 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -106,6 +106,7 @@ enum mig_rp_message_type {
    dynamic creation of migration */
 
 static MigrationState *current_migration;
+static MigrationIncomingState *current_incoming;
 
 static bool migration_object_check(MigrationState *ms, Error **errp);
 static int migration_maybe_pause(MigrationState *s,
@@ -121,6 +122,22 @@ void migration_object_init(void)
     assert(!current_migration);
     current_migration = MIGRATION_OBJ(object_new(TYPE_MIGRATION));
 
+    /*
+     * Init the migrate incoming object as well no matter whether
+     * we'll use it or not.
+     */
+    assert(!current_incoming);
+    current_incoming = g_new0(MigrationIncomingState, 1);
+    current_incoming->state = MIGRATION_STATUS_NONE;
+    current_incoming->postcopy_remote_fds =
+        g_array_new(FALSE, TRUE, sizeof(struct PostCopyFD));
+    qemu_mutex_init(&current_incoming->rp_mutex);
+    qemu_event_init(&current_incoming->main_thread_load_event, false);
+    qemu_sem_init(&current_incoming->postcopy_pause_sem_dst, 0);
+    qemu_sem_init(&current_incoming->postcopy_pause_sem_fault, 0);
+
+    init_dirty_bitmap_incoming_migration();
+
     if (!migration_object_check(current_migration, &err)) {
         error_report_err(err);
         exit(1);
@@ -151,24 +168,8 @@ MigrationState *migrate_get_current(void)
 
 MigrationIncomingState *migration_incoming_get_current(void)
 {
-    static bool once;
-    static MigrationIncomingState mis_current;
-
-    if (!once) {
-        mis_current.state = MIGRATION_STATUS_NONE;
-        memset(&mis_current, 0, sizeof(MigrationIncomingState));
-        mis_current.postcopy_remote_fds = g_array_new(FALSE, TRUE,
-                                                   sizeof(struct PostCopyFD));
-        qemu_mutex_init(&mis_current.rp_mutex);
-        qemu_event_init(&mis_current.main_thread_load_event, false);
-        qemu_sem_init(&mis_current.postcopy_pause_sem_dst, 0);
-        qemu_sem_init(&mis_current.postcopy_pause_sem_fault, 0);
-
-        init_dirty_bitmap_incoming_migration();
-
-        once = true;
-    }
-    return &mis_current;
+    assert(current_incoming);
+    return current_incoming;
 }
 
 void migration_incoming_state_destroy(void)