migration: qemu_savevm_state_cleanup becomes mandatory operation

since commit
    commit 94f5a43704129ca4995aa3385303c5ae225bde42
    Author: Liang Li <liang.z.li@intel.com>
    Date:   Mon Nov 2 15:37:00 2015 +0800

    migration: defer migration_end & blk_mig_cleanup

when actual .cleanup callbacks calling was removed from complete operations.

The patch fixes regression introduced by the commit above results in
100% reliable assert for virtio-scsi VM with iothreads enabled during
'virsh create-snapshot' operation:
    assert(i != mr->ioeventfd_nb);
    memory_region_del_eventfd
    virtio_pci_set_host_notifier_internal
    virtio_pci_set_host_notifier
    virtio_scsi_dataplane_start
    virtio_scsi_handle_cmd
    virtio_queue_notify_vq
    virtio_queue_host_notifier_read
    aio_dispatch

Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Liang Li <liang.z.li@intel.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Juan Quintela <quintela@redhat.com>
CC: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>

diff --git a/migration/savevm.c b/migration/savevm.c
index 0596f7b..be52314 100644 (file)
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1179,8 +1179,8 @@ static int qemu_savevm_state(QEMUFile *f, Error **errp)
         qemu_savevm_state_complete_precopy(f);
         ret = qemu_file_get_error(f);
     }
+    qemu_savevm_state_cleanup();
     if (ret != 0) {
-        qemu_savevm_state_cleanup();
         error_setg_errno(errp, -ret, "Error while writing VM state");
     }
     return ret;