[v2,1/7] ethdev: add min/max MTU to device info

diff --git a/doc/guides/rel_notes/deprecation.rst b/doc/guides/rel_notes/deprecation.rst
index 1b4fcb7e6..0e85c47f3 100644
--- a/doc/guides/rel_notes/deprecation.rst
+++ b/doc/guides/rel_notes/deprecation.rst
@@ -56,18 +56,6 @@  Deprecation Notices
   Target release for removal of the legacy API will be defined once most
   PMDs have switched to rte_flow.
 
-* ethdev: Maximum and minimum MTU values vary between hardware devices. In
-  hardware agnostic DPDK applications access to such information would allow
-  a more accurate way of validating and setting supported MTU values on a per
-  device basis rather than using a defined default for all devices. To
-  resolve this, the following members will be added to ``rte_eth_dev_info``.
-  Note: these can be added to fit a hole in the existing structure for amd64
-  but not for 32-bit, as such ABI change will occur as size of the structure
-  will increase.
-
-  - Member ``uint16_t min_mtu`` the minimum MTU allowed.
-  - Member ``uint16_t max_mtu`` the maximum MTU allowed.
-
 * meter: New ``rte_color`` definition will be added in 19.02 and that will
   replace ``enum rte_meter_color`` in meter library in 19.05. This will help
   to consolidate color definition, which is currently replicated in many places,
diff --git a/doc/guides/rel_notes/release_19_05.rst b/doc/guides/rel_notes/release_19_05.rst
index 61a2c7383..6ba3fab9a 100644
--- a/doc/guides/rel_notes/release_19_05.rst
+++ b/doc/guides/rel_notes/release_19_05.rst
@@ -136,6 +136,12 @@  ABI Changes
    Also, make sure to start the actual text at the margin.
    =========================================================
 
+* ethdev: Additional fields in rte_eth_dev_info.
+
+  The ``rte_eth_dev_info`` structure has had two extra fields
+  added: ``min_mtu`` and ``max_mtu``. Each of these are of type ``uint16_t``.
+  The values of these fields can be set specifically by the PMD drivers as
+  supported values can vary from device to device.
 
 Shared Library Versions
 -----------------------
@@ -171,7 +177,7 @@  The libraries prepended with a plus sign were incremented in this version.
      librte_distributor.so.1
      librte_eal.so.9
      librte_efd.so.1
-     librte_ethdev.so.11
+   + librte_ethdev.so.12
      librte_eventdev.so.6
      librte_flow_classify.so.1
      librte_gro.so.1
diff --git a/lib/librte_ethdev/Makefile b/lib/librte_ethdev/Makefile
index e09c4263a..8d4a02630 100644
--- a/lib/librte_ethdev/Makefile
+++ b/lib/librte_ethdev/Makefile
@@ -16,7 +16,7 @@  LDLIBS += -lrte_mbuf -lrte_kvargs -lrte_cmdline -lrte_meter
 
 EXPORT_MAP := rte_ethdev_version.map
 
-LIBABIVER := 11
+LIBABIVER := 12
 
 SRCS-y += ethdev_private.c
 SRCS-y += rte_ethdev.c
diff --git a/lib/librte_ethdev/meson.build b/lib/librte_ethdev/meson.build
index e98942ff8..8d6165b2a 100644
--- a/lib/librte_ethdev/meson.build
+++ b/lib/librte_ethdev/meson.build
@@ -2,7 +2,7 @@ 
 # Copyright(c) 2017 Intel Corporation
 
 name = 'ethdev'
-version = 11
+version = 12
 allow_experimental_apis = true
 sources = files('ethdev_private.c',
 	'ethdev_profile.c',
diff --git a/lib/librte_ethdev/rte_ethdev.c b/lib/librte_ethdev/rte_ethdev.c
index 85c179496..fe72e88c2 100644
--- a/lib/librte_ethdev/rte_ethdev.c
+++ b/lib/librte_ethdev/rte_ethdev.c
@@ -2524,6 +2524,8 @@  rte_eth_dev_info_get(uint16_t port_id, struct rte_eth_dev_info *dev_info)
 	dev_info->rx_desc_lim = lim;
 	dev_info->tx_desc_lim = lim;
 	dev_info->device = dev->device;
+	dev_info->min_mtu = ETHER_MIN_MTU;
+	dev_info->max_mtu = UINT16_MAX;
 
 	RTE_FUNC_PTR_OR_RET(*dev->dev_ops->dev_infos_get);
 	(*dev->dev_ops->dev_infos_get)(dev, dev_info);
@@ -2587,12 +2589,25 @@  int
 rte_eth_dev_set_mtu(uint16_t port_id, uint16_t mtu)
 {
 	int ret;
+	struct rte_eth_dev_info dev_info;
 	struct rte_eth_dev *dev;
 
 	RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, -ENODEV);
 	dev = &rte_eth_devices[port_id];
 	RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops->mtu_set, -ENOTSUP);
 
+	/*
+	 * Check if the device supports dev_infos_get, if it does not
+	 * skip min_mtu/max_mtu validation here as this requires values
+	 * that are populated within the call to rte_eth_dev_info_get()
+	 * which relies on dev->dev_ops->dev_infos_get.
+	 */
+	if (*dev->dev_ops->dev_infos_get != NULL) {
+		rte_eth_dev_info_get(port_id, &dev_info);
+		if (mtu < dev_info.min_mtu || mtu > dev_info.max_mtu)
+			return -EINVAL;
+	}
+
 	ret = (*dev->dev_ops->mtu_set)(dev, mtu);
 	if (!ret)
 		dev->data->mtu = mtu;
diff --git a/lib/librte_ethdev/rte_ethdev.h b/lib/librte_ethdev/rte_ethdev.h
index a3c864a13..bea1bd2d4 100644
--- a/lib/librte_ethdev/rte_ethdev.h
+++ b/lib/librte_ethdev/rte_ethdev.h
@@ -1086,6 +1086,8 @@  struct rte_eth_dev_info {
 	const char *driver_name; /**< Device Driver name. */
 	unsigned int if_index; /**< Index to bound host interface, or 0 if none.
 		Use if_indextoname() to translate into an interface name. */
+	uint16_t min_mtu;	/**< Minimum MTU allowed */
+	uint16_t max_mtu;	/**< Maximum MTU allowed */
 	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. */
@@ -2202,6 +2204,33 @@  void rte_eth_macaddr_get(uint16_t port_id, struct ether_addr *mac_addr);
 /**
  * Retrieve the contextual information of an Ethernet device.
  *
+ * As part of this function, a number of of fields in dev_info will be
+ * initialized as follows:
+ *
+ * rx_desc_lim = lim
+ * tx_desc_lim = lim
+ *
+ * Where lim is defined within the rte_eth_dev_info_get as
+ *
+ *  const struct rte_eth_desc_lim lim = {
+ *      .nb_max = UINT16_MAX,
+ *      .nb_min = 0,
+ *      .nb_align = 1,
+ *  };
+ *
+ * device = dev->device
+ * min_mtu = ETHER_MIN_MTU
+ * max_mtu = UINT16_MAX
+ *
+ * The following fields will be populated if support for dev_infos_get()
+ * exists for the device and the rte_eth_dev 'dev' has been populated
+ * successfully with a call to it:
+ *
+ * driver_name = dev->device->driver->name
+ * nb_rx_queues = dev->data->nb_rx_queues
+ * nb_tx_queues = dev->data->nb_tx_queues
+ * dev_flags = &dev->data->dev_flags
+ *
  * @param port_id
  *   The port identifier of the Ethernet device.
  * @param dev_info
@@ -2298,7 +2327,9 @@  int rte_eth_dev_get_mtu(uint16_t port_id, uint16_t *mtu);
  *   - (-ENOTSUP) if operation is not supported.
  *   - (-ENODEV) if *port_id* invalid.
  *   - (-EIO) if device is removed.
- *   - (-EINVAL) if *mtu* invalid.
+ *   - (-EINVAL) if *mtu* invalid, validation of mtu can occur within
+ *     rte_eth_dev_set_mtu if dev_infos_get is supported by the device or
+ *     when the mtu is set using dev->dev_ops->mtu_set.
  *   - (-EBUSY) if operation is not allowed when the port is running
  */
 int rte_eth_dev_set_mtu(uint16_t port_id, uint16_t mtu);