+/**
+ * DPDK callback to configure multicast addresses.
+ *
+ * @param dev
+ * Pointer to Ethernet device structure.
+ * @param list
+ * List of MAC addresses to register.
+ * @param num
+ * Number of entries in list.
+ *
+ * @return
+ * 0 on success, negative errno value otherwise and rte_errno is set.
+ */
+int
+mlx4_set_mc_addr_list(struct rte_eth_dev *dev, struct rte_ether_addr *list,
+ uint32_t num)
+{
+ struct mlx4_priv *priv = dev->data->dev_private;
+ struct rte_flow_error error;
+ int ret;
+
+ if (num > RTE_DIM(priv->mac)) {
+ rte_errno = EINVAL;
+ return -rte_errno;
+ }
+ /*
+ * Make sure there is enough room to increase the number of
+ * multicast entries without overwriting standard entries.
+ */
+ if (num > priv->mac_mc) {
+ unsigned int i;
+
+ for (i = RTE_DIM(priv->mac) - num;
+ i != RTE_DIM(priv->mac) - priv->mac_mc;
+ ++i)
+ if (!rte_is_zero_ether_addr(&priv->mac[i])) {
+ rte_errno = EBUSY;
+ return -rte_errno;
+ }
+ } else if (num < priv->mac_mc) {
+ /* Clear unused entries. */
+ memset(priv->mac + RTE_DIM(priv->mac) - priv->mac_mc,
+ 0,
+ sizeof(priv->mac[0]) * (priv->mac_mc - num));
+ }
+ memcpy(priv->mac + RTE_DIM(priv->mac) - num, list, sizeof(*list) * num);
+ priv->mac_mc = num;
+ ret = mlx4_flow_sync(priv, &error);
+ if (!ret)
+ return 0;
+ ERROR("failed to synchronize flow rules after modifying MC list,"
+ " (code %d, \"%s\"), flow error type %d, cause %p, message: %s",
+ rte_errno, strerror(rte_errno), error.type, error.cause,
+ error.message ? error.message : "(unspecified)");
+ return ret;
+}
+