[v7,1/3] ethdev: support API to set max LRO packet size

diff --git a/doc/guides/nics/features.rst b/doc/guides/nics/features.rst
index 7a31cf7..2138ce3 100644
--- a/doc/guides/nics/features.rst
+++ b/doc/guides/nics/features.rst
@@ -193,10 +193,12 @@  LRO
 Supports Large Receive Offload.
 
 * **[uses]       rte_eth_rxconf,rte_eth_rxmode**: ``offloads:DEV_RX_OFFLOAD_TCP_LRO``.
+  ``dev_conf.rxmode.max_lro_pkt_size``.
 * **[implements] datapath**: ``LRO functionality``.
 * **[implements] rte_eth_dev_data**: ``lro``.
 * **[provides]   mbuf**: ``mbuf.ol_flags:PKT_RX_LRO``, ``mbuf.tso_segsz``.
 * **[provides]   rte_eth_dev_info**: ``rx_offload_capa,rx_queue_offload_capa:DEV_RX_OFFLOAD_TCP_LRO``.
+* **[provides]   rte_eth_dev_info**: ``max_lro_pkt_size``.
 
 
 .. _nic_features_tso:
diff --git a/doc/guides/rel_notes/deprecation.rst b/doc/guides/rel_notes/deprecation.rst
index fad208b..dbfb059 100644
--- a/doc/guides/rel_notes/deprecation.rst
+++ b/doc/guides/rel_notes/deprecation.rst
@@ -83,10 +83,6 @@  Deprecation Notices
   This scheme will allow PMDs to avoid lookup to internal ptype table on Rx and
   thereby improve Rx performance if application wishes do so.
 
-* ethdev: New 32-bit fields may be added for maximum LRO session size, in
-  struct ``rte_eth_dev_info`` for the port capability and in struct
-  ``rte_eth_rxmode`` for the port configuration.
-
 * cryptodev: support for using IV with all sizes is added, J0 still can
   be used but only when IV length in following structs ``rte_crypto_auth_xform``,
   ``rte_crypto_aead_xform`` is set to zero. When IV length is greater or equal
diff --git a/doc/guides/rel_notes/release_19_11.rst b/doc/guides/rel_notes/release_19_11.rst
index da48051..d29acbe 100644
--- a/doc/guides/rel_notes/release_19_11.rst
+++ b/doc/guides/rel_notes/release_19_11.rst
@@ -444,6 +444,14 @@  ABI Changes
 * ipsec: The field ``replay_win_sz`` has been removed from the structure
   ``rte_ipsec_sa_prm`` as it has been added to the security library.
 
+* ethdev: Added 32-bit fields for maximum LRO aggregated packet size, in
+  struct ``rte_eth_dev_info`` for the port capability and in struct
+  ``rte_eth_rxmode`` for the port configuration.
+  Application should use the new field in struct ``rte_eth_rxmode`` to configure
+  the requested size.
+  PMD should use the new field in struct ``rte_eth_dev_info`` to report the
+  supported port capability.
+
 
 Shared Library Versions
 -----------------------
diff --git a/lib/librte_ethdev/rte_ethdev.c b/lib/librte_ethdev/rte_ethdev.c
index 652c369..55e0e0d 100644
--- a/lib/librte_ethdev/rte_ethdev.c
+++ b/lib/librte_ethdev/rte_ethdev.c
@@ -1136,6 +1136,33 @@  struct rte_eth_dev *
 	return name;
 }
 
+static inline int
+check_lro_pkt_size(uint16_t port_id, uint32_t config_size,
+		   uint32_t max_rx_pkt_len, uint32_t dev_info_size)
+{
+	int ret = 0;
+
+	if (dev_info_size == 0) {
+		if (config_size != max_rx_pkt_len) {
+			RTE_ETHDEV_LOG(ERR, "Ethdev port_id=%d max_lro_pkt_size"
+				       " %u != %u is not allowed\n",
+				       port_id, config_size, max_rx_pkt_len);
+			ret = -EINVAL;
+		}
+	} else if (config_size > dev_info_size) {
+		RTE_ETHDEV_LOG(ERR, "Ethdev port_id=%d max_lro_pkt_size %u "
+			       "> max allowed value %u\n", port_id, config_size,
+			       dev_info_size);
+		ret = -EINVAL;
+	} else if (config_size < RTE_ETHER_MIN_LEN) {
+		RTE_ETHDEV_LOG(ERR, "Ethdev port_id=%d max_lro_pkt_size %u "
+			       "< min allowed value %u\n", port_id, config_size,
+			       (unsigned int)RTE_ETHER_MIN_LEN);
+		ret = -EINVAL;
+	}
+	return ret;
+}
+
 int
 rte_eth_dev_configure(uint16_t port_id, uint16_t nb_rx_q, uint16_t nb_tx_q,
 		      const struct rte_eth_conf *dev_conf)
@@ -1266,6 +1293,22 @@  struct rte_eth_dev *
 							RTE_ETHER_MAX_LEN;
 	}
 
+	/*
+	 * If LRO is enabled, check that the maximum aggregated packet
+	 * size is supported by the configured device.
+	 */
+	if (dev_conf->rxmode.offloads & DEV_RX_OFFLOAD_TCP_LRO) {
+		if (dev_conf->rxmode.max_lro_pkt_size == 0)
+			dev->data->dev_conf.rxmode.max_lro_pkt_size =
+				dev->data->dev_conf.rxmode.max_rx_pkt_len;
+		ret = check_lro_pkt_size(port_id,
+				dev->data->dev_conf.rxmode.max_lro_pkt_size,
+				dev->data->dev_conf.rxmode.max_rx_pkt_len,
+				dev_info.max_lro_pkt_size);
+		if (ret != 0)
+			goto rollback;
+	}
+
 	/* Any requested offloading must be within its device capabilities */
 	if ((dev_conf->rxmode.offloads & dev_info.rx_offload_capa) !=
 	     dev_conf->rxmode.offloads) {
@@ -1770,6 +1813,22 @@  struct rte_eth_dev *
 		return -EINVAL;
 	}
 
+	/*
+	 * If LRO is enabled, check that the maximum aggregated packet
+	 * size is supported by the configured device.
+	 */
+	if (local_conf.offloads & DEV_RX_OFFLOAD_TCP_LRO) {
+		if (dev->data->dev_conf.rxmode.max_lro_pkt_size == 0)
+			dev->data->dev_conf.rxmode.max_lro_pkt_size =
+				dev->data->dev_conf.rxmode.max_rx_pkt_len;
+		int ret = check_lro_pkt_size(port_id,
+				dev->data->dev_conf.rxmode.max_lro_pkt_size,
+				dev->data->dev_conf.rxmode.max_rx_pkt_len,
+				dev_info.max_lro_pkt_size);
+		if (ret != 0)
+			return ret;
+	}
+
 	ret = (*dev->dev_ops->rx_queue_setup)(dev, rx_queue_id, nb_rx_desc,
 					      socket_id, &local_conf, mp);
 	if (!ret) {
diff --git a/lib/librte_ethdev/rte_ethdev.h b/lib/librte_ethdev/rte_ethdev.h
index 44d77b3..1b76df5 100644
--- a/lib/librte_ethdev/rte_ethdev.h
+++ b/lib/librte_ethdev/rte_ethdev.h
@@ -395,6 +395,8 @@  struct rte_eth_rxmode {
 	/** The multi-queue packet distribution mode to be used, e.g. RSS. */
 	enum rte_eth_rx_mq_mode mq_mode;
 	uint32_t max_rx_pkt_len;  /**< Only used if JUMBO_FRAME enabled. */
+	/** Maximum allowed size of LRO aggregated packet. */
+	uint32_t max_lro_pkt_size;
 	uint16_t split_hdr_size;  /**< hdr buf size (header_split enabled).*/
 	/**
 	 * Per-port Rx offloads to be set using DEV_RX_OFFLOAD_* flags.
@@ -1218,6 +1220,8 @@  struct rte_eth_dev_info {
 	const uint32_t *dev_flags; /**< Device flags */
 	uint32_t min_rx_bufsize; /**< Minimum size of RX buffer. */
 	uint32_t max_rx_pktlen; /**< Maximum configurable length of RX pkt. */
+	/** Maximum configurable size of LRO aggregated packet. */
+	uint32_t max_lro_pkt_size;
 	uint16_t max_rx_queues; /**< Maximum number of RX queues. */
 	uint16_t max_tx_queues; /**< Maximum number of TX queues. */
 	uint32_t max_mac_addrs; /**< Maximum number of MAC addresses. */