int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev) { BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); VirtioBusState *vbus = VIRTIO_BUS(qbus); VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus); int i, r; if (!k->set_host_notifier) { fprintf(stderr, "binding does not support host notifiers\n"); r = -ENOSYS; goto fail; } for (i = 0; i < hdev->nvqs; ++i) { r = k->set_host_notifier(qbus->parent, hdev->vq_index + i, true); if (r < 0) { fprintf(stderr, "vhost VQ %d notifier binding failed: %d\n", i, -r); goto fail_vq; } } return 0; fail_vq: while (--i >= 0) { r = k->set_host_notifier(qbus->parent, hdev->vq_index + i, false); if (r < 0) { fprintf(stderr, "vhost VQ %d notifier cleanup error: %d\n", i, -r); fflush(stderr); } assert (r >= 0); } fail: return r; }