1 files changed, 47 insertions, 35 deletions

diff --git a/migration/migration.c b/migration/migration.c
index 219447dea1..d5f705ceef 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -199,6 +199,47 @@ void migration_object_init(void)
     dirty_bitmap_mig_init();
 }
 
+typedef struct {
+    QEMUBH *bh;
+    QEMUBHFunc *cb;
+    void *opaque;
+} MigrationBH;
+
+static void migration_bh_dispatch_bh(void *opaque)
+{
+    MigrationState *s = migrate_get_current();
+    MigrationBH *migbh = opaque;
+
+    /* cleanup this BH */
+    qemu_bh_delete(migbh->bh);
+    migbh->bh = NULL;
+
+    /* dispatch the other one */
+    migbh->cb(migbh->opaque);
+    object_unref(OBJECT(s));
+
+    g_free(migbh);
+}
+
+void migration_bh_schedule(QEMUBHFunc *cb, void *opaque)
+{
+    MigrationState *s = migrate_get_current();
+    MigrationBH *migbh = g_new0(MigrationBH, 1);
+    QEMUBH *bh = qemu_bh_new(migration_bh_dispatch_bh, migbh);
+
+    /* Store these to dispatch when the BH runs */
+    migbh->bh = bh;
+    migbh->cb = cb;
+    migbh->opaque = opaque;
+
+    /*
+     * Ref the state for bh, because it may be called when
+     * there're already no other refs
+     */
+    object_ref(OBJECT(s));
+    qemu_bh_schedule(bh);
+}
+
 void migration_cancel(const Error *error)
 {
     if (error) {
@@ -646,7 +687,6 @@ static void process_incoming_migration_bh(void *opaque)
      */
     migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE,
                       MIGRATION_STATUS_COMPLETED);
-    qemu_bh_delete(mis->bh);
     migration_incoming_state_destroy();
 }
 
@@ -712,8 +752,7 @@ process_incoming_migration_co(void *opaque)
         goto fail;
     }
 
-    mis->bh = qemu_bh_new(process_incoming_migration_bh, mis);
-    qemu_bh_schedule(mis->bh);
+    migration_bh_schedule(process_incoming_migration_bh, mis);
     return;
 fail:
     migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE,
@@ -1274,9 +1313,6 @@ void migrate_set_state(int *state, int old_state, int new_state)
 
 static void migrate_fd_cleanup(MigrationState *s)
 {
-    qemu_bh_delete(s->cleanup_bh);
-    s->cleanup_bh = NULL;
-
     g_free(s->hostname);
     s->hostname = NULL;
     json_writer_free(s->vmdesc);
@@ -1330,21 +1366,9 @@ static void migrate_fd_cleanup(MigrationState *s)
     yank_unregister_instance(MIGRATION_YANK_INSTANCE);
 }
 
-static void migrate_fd_cleanup_schedule(MigrationState *s)
-{
-    /*
-     * Ref the state for bh, because it may be called when
-     * there're already no other refs
-     */
-    object_ref(OBJECT(s));
-    qemu_bh_schedule(s->cleanup_bh);
-}
-
 static void migrate_fd_cleanup_bh(void *opaque)
 {
-    MigrationState *s = opaque;
-    migrate_fd_cleanup(s);
-    object_unref(OBJECT(s));
+    migrate_fd_cleanup(opaque);
 }
 
 void migrate_set_error(MigrationState *s, const Error *error)
@@ -1567,8 +1591,6 @@ int migrate_init(MigrationState *s, Error **errp)
      * parameters/capabilities that the user set, and
      * locks.
      */
-    s->cleanup_bh = 0;
-    s->vm_start_bh = 0;
     s->to_dst_file = NULL;
     s->state = MIGRATION_STATUS_NONE;
     s->rp_state.from_dst_file = NULL;
@@ -3138,7 +3160,8 @@ static void migration_iteration_finish(MigrationState *s)
         error_report("%s: Unknown ending state %d", __func__, s->state);
         break;
     }
-    migrate_fd_cleanup_schedule(s);
+
+    migration_bh_schedule(migrate_fd_cleanup_bh, s);
     bql_unlock();
 }
 
@@ -3169,7 +3192,7 @@ static void bg_migration_iteration_finish(MigrationState *s)
         break;
     }
 
-    migrate_fd_cleanup_schedule(s);
+    migration_bh_schedule(migrate_fd_cleanup_bh, s);
     bql_unlock();
 }
 
@@ -3375,9 +3398,6 @@ static void bg_migration_vm_start_bh(void *opaque)
 {
     MigrationState *s = opaque;
 
-    qemu_bh_delete(s->vm_start_bh);
-    s->vm_start_bh = NULL;
-
     vm_resume(s->vm_old_state);
     migration_downtime_end(s);
 }
@@ -3483,9 +3503,7 @@ static void *bg_migration_thread(void *opaque)
      * calling VM state change notifiers from vm_start() would initiate
      * writes to virtio VQs memory which is in write-protected region.
      */
-    s->vm_start_bh = qemu_bh_new(bg_migration_vm_start_bh, s);
-    qemu_bh_schedule(s->vm_start_bh);
-
+    migration_bh_schedule(bg_migration_vm_start_bh, s);
     bql_unlock();
 
     while (migration_is_active(s)) {
@@ -3541,12 +3559,6 @@ void migrate_fd_connect(MigrationState *s, Error *error_in)
     migrate_error_free(s);
 
     s->expected_downtime = migrate_downtime_limit();
-    if (resume) {
-        assert(s->cleanup_bh);
-    } else {
-        assert(!s->cleanup_bh);
-        s->cleanup_bh = qemu_bh_new(migrate_fd_cleanup_bh, s);
-    }
     if (error_in) {
         migrate_fd_error(s, error_in);
         if (resume) {