+/*
+ * Helper function to arrange max_rx_pktlen value and JUMBO_FRAME offload,
+ * MTU is also aligned if JUMBO_FRAME offload is not set.
+ *
+ * port->dev_info should be set before calling this function.
+ *
+ * return 0 on success, negative on error
+ */
+int
+update_jumbo_frame_offload(portid_t portid)
+{
+ struct rte_port *port = &ports[portid];
+ uint32_t eth_overhead;
+ uint64_t rx_offloads;
+ int ret;
+ bool on;
+
+ /* Update the max_rx_pkt_len to have MTU as RTE_ETHER_MTU */
+ if (port->dev_info.max_mtu != UINT16_MAX &&
+ port->dev_info.max_rx_pktlen > port->dev_info.max_mtu)
+ eth_overhead = port->dev_info.max_rx_pktlen -
+ port->dev_info.max_mtu;
+ else
+ eth_overhead = RTE_ETHER_HDR_LEN + RTE_ETHER_CRC_LEN;
+
+ rx_offloads = port->dev_conf.rxmode.offloads;
+
+ /* Default config value is 0 to use PMD specific overhead */
+ if (port->dev_conf.rxmode.max_rx_pkt_len == 0)
+ port->dev_conf.rxmode.max_rx_pkt_len = RTE_ETHER_MTU + eth_overhead;
+
+ if (port->dev_conf.rxmode.max_rx_pkt_len <= RTE_ETHER_MTU + eth_overhead) {
+ rx_offloads &= ~DEV_RX_OFFLOAD_JUMBO_FRAME;
+ on = false;
+ } else {
+ if ((port->dev_info.rx_offload_capa & DEV_RX_OFFLOAD_JUMBO_FRAME) == 0) {
+ printf("Frame size (%u) is not supported by port %u\n",
+ port->dev_conf.rxmode.max_rx_pkt_len,
+ portid);
+ return -1;
+ }
+ rx_offloads |= DEV_RX_OFFLOAD_JUMBO_FRAME;
+ on = true;
+ }
+
+ if (rx_offloads != port->dev_conf.rxmode.offloads) {
+ uint16_t qid;
+
+ port->dev_conf.rxmode.offloads = rx_offloads;
+
+ /* Apply JUMBO_FRAME offload configuration to Rx queue(s) */
+ for (qid = 0; qid < port->dev_info.nb_rx_queues; qid++) {
+ if (on)
+ port->rx_conf[qid].offloads |= DEV_RX_OFFLOAD_JUMBO_FRAME;
+ else
+ port->rx_conf[qid].offloads &= ~DEV_RX_OFFLOAD_JUMBO_FRAME;
+ }
+ }
+
+ /* If JUMBO_FRAME is set MTU conversion done by ethdev layer,
+ * if unset do it here
+ */
+ if ((rx_offloads & DEV_RX_OFFLOAD_JUMBO_FRAME) == 0) {
+ ret = rte_eth_dev_set_mtu(portid,
+ port->dev_conf.rxmode.max_rx_pkt_len - eth_overhead);
+ if (ret)
+ printf("Failed to set MTU to %u for port %u\n",
+ port->dev_conf.rxmode.max_rx_pkt_len - eth_overhead,
+ portid);
+ }
+
+ return 0;
+}
+