+ msg.size = sizeof(msg.payload.memory.nregions);
+ msg.size += sizeof(msg.payload.memory.padding);
+ msg.size += fd_num * sizeof(VhostUserMemoryRegion);
+
+ vhost_user_write(dev, &msg, fds, fd_num);
+
+ return 0;
+}
+
+static int vhost_user_set_vring_addr(struct vhost_dev *dev,
+ struct vhost_vring_addr *addr)
+{
+ VhostUserMsg msg = {
+ .request = VHOST_USER_SET_VRING_ADDR,
+ .flags = VHOST_USER_VERSION,
+ .payload.addr = *addr,
+ .size = sizeof(msg.payload.addr),
+ };
+
+ vhost_user_write(dev, &msg, NULL, 0);
+
+ return 0;
+}
+
+static int vhost_user_set_vring_endian(struct vhost_dev *dev,
+ struct vhost_vring_state *ring)
+{
+ error_report("vhost-user trying to send unhandled ioctl");
+ return -1;
+}
+
+static int vhost_set_vring(struct vhost_dev *dev,
+ unsigned long int request,
+ struct vhost_vring_state *ring)
+{
+ VhostUserMsg msg = {
+ .request = request,
+ .flags = VHOST_USER_VERSION,
+ .payload.state = *ring,
+ .size = sizeof(msg.payload.state),
+ };
+
+ vhost_user_write(dev, &msg, NULL, 0);
+
+ return 0;
+}
+
+static int vhost_user_set_vring_num(struct vhost_dev *dev,
+ struct vhost_vring_state *ring)
+{
+ return vhost_set_vring(dev, VHOST_USER_SET_VRING_NUM, ring);
+}
+
+static int vhost_user_set_vring_base(struct vhost_dev *dev,
+ struct vhost_vring_state *ring)
+{
+ return vhost_set_vring(dev, VHOST_USER_SET_VRING_BASE, ring);
+}
+
+static int vhost_user_set_vring_enable(struct vhost_dev *dev, int enable)
+{
+ int i;
+
+ if (!virtio_has_feature(dev->features, VHOST_USER_F_PROTOCOL_FEATURES)) {
+ return -1;
+ }
+
+ for (i = 0; i < dev->nvqs; ++i) {
+ struct vhost_vring_state state = {
+ .index = dev->vq_index + i,
+ .num = enable,
+ };
+
+ vhost_set_vring(dev, VHOST_USER_SET_VRING_ENABLE, &state);
+ }
+
+ return 0;
+}
+
+static int vhost_user_get_vring_base(struct vhost_dev *dev,
+ struct vhost_vring_state *ring)
+{
+ VhostUserMsg msg = {
+ .request = VHOST_USER_GET_VRING_BASE,
+ .flags = VHOST_USER_VERSION,
+ .payload.state = *ring,
+ .size = sizeof(msg.payload.state),
+ };
+
+ vhost_user_write(dev, &msg, NULL, 0);
+
+ if (vhost_user_read(dev, &msg) < 0) {