+ /* MTU does not include header and CRC. */
+ max_frame_len = ETHER_HDR_LEN + mtu + ETHER_CRC_LEN;
+ /* Check if at least one queue is going to need a SGE update. */
+ for (i = 0; i != priv->rxqs_n; ++i) {
+ struct rxq *rxq = (*priv->rxqs)[i];
+ unsigned int mb_len;
+ unsigned int size = RTE_PKTMBUF_HEADROOM + max_frame_len;
+ unsigned int sges_n;
+
+ if (rxq == NULL)
+ continue;
+ mb_len = rte_pktmbuf_data_room_size(rxq->mp);
+ assert(mb_len >= RTE_PKTMBUF_HEADROOM);
+ /*
+ * Determine the number of SGEs needed for a full packet
+ * and round it to the next power of two.
+ */
+ sges_n = log2above((size / mb_len) + !!(size % mb_len));
+ if (sges_n != rxq->sges_n)
+ break;
+ }
+ /*
+ * If all queues have the right number of SGEs, a simple rehash
+ * of their buffers is enough, otherwise SGE information can only
+ * be updated in a queue by recreating it. All resources that depend
+ * on queues (flows, indirection tables) must be recreated as well in
+ * that case.
+ */
+ rehash = (i == priv->rxqs_n);
+ if (!rehash) {
+ /* Clean up everything as with mlx5_dev_stop(). */
+ priv_special_flow_disable_all(priv);
+ priv_mac_addrs_disable(priv);
+ priv_destroy_hash_rxqs(priv);
+ priv_fdir_disable(priv);
+ priv_dev_interrupt_handler_uninstall(priv, dev);
+ }
+recover: