doc: add known issue for i40e statistics

[dpdk.git] / doc / guides / nics / i40e.rst

diff --git a/doc/guides/nics/i40e.rst b/doc/guides/nics/i40e.rst
index da695af..b890613 100644 (file)
--- a/doc/guides/nics/i40e.rst
+++ b/doc/guides/nics/i40e.rst
@@ -64,6 +64,7 @@ Features of the I40E PMD are:
 - SR-IOV VF
 - Hot plug
 - IEEE1588/802.1AS timestamping
+- VF Daemon (VFD) - EXPERIMENTAL
 
 
 Prerequisites
@@ -164,13 +165,13 @@ devices managed by ``librte_pmd_i40e`` in the Linux operating system.
 
    .. code-block:: console
 
-      ./tools/dpdk_nic_bind.py --bind igb_uio 0000:83:00.0
+      ./usertools/dpdk-devbind.py --bind igb_uio 0000:83:00.0
 
    Or setup VFIO permissions for regular users and then bind to ``vfio-pci``:
 
    .. code-block:: console
 
-      ./tools/dpdk_nic_bind.py --bind vfio-pci 0000:83:00.0
+      ./usertools/dpdk-devbind.py --bind vfio-pci 0000:83:00.0
 
 #. Start ``testpmd`` with basic parameters:
 
@@ -411,3 +412,58 @@ configuration passed on the EAL command line.
 
 The floating VEB functionality requires a NIC firmware version of 5.0
 or greater.
+
+
+Limitations or Known issues
+---------------------------
+
+MPLS packet classification on X710/XL710
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+For firmware versions prior to 5.0, MPLS packets are not recognized by the NIC.
+The L2 Payload flow type in flow director can be used to classify MPLS packet
+by using a command in testpmd like:
+
+   testpmd> flow_director_filter 0 mode IP add flow l2_payload ether \
+            0x8847 flexbytes () fwd pf queue <N> fd_id <M>
+
+With the NIC firmware version 5.0 or greater, some limited MPLS support
+is added: Native MPLS (MPLS in Ethernet) skip is implemented, while no
+new packet type, no classification or offload are possible. With this change,
+L2 Payload flow type in flow director cannot be used to classify MPLS packet
+as with previous firmware versions. Meanwhile, the Ethertype filter can be
+used to classify MPLS packet by using a command in testpmd like:
+
+   testpmd> ethertype_filter 0 add mac_ignr 00:00:00:00:00:00 ethertype \
+            0x8847 fwd queue <M>
+
+16 Byte Descriptor cannot be used on DPDK VF
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+If the Linux i40e kernel driver is used as host driver, while DPDK i40e PMD
+is used as the VF driver, DPDK cannot choose 16 byte receive descriptor. That
+is to say, user should keep ``CONFIG_RTE_LIBRTE_I40E_16BYTE_RX_DESC=n`` in
+config file.
+
+Link down with i40e kernel driver after DPDK application exist
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+After DPDK application quit, and the device is bound back to Linux i40e
+kernel driver, the link cannot be up after ``ifconfig <dev> up``.
+To work around this issue, ``ethtool -s <dev> autoneg on`` should be
+set first and then the link can be brought up through ``ifconfig <dev> up``.
+
+NOTE: requires Linux kernel i40e driver version >= 1.4.X
+
+Receive packets with Ethertype 0x88A8
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Due to the FW limitation, PF can receive packets with Ethertype 0x88A8
+only when floating VEB is disabled.
+
+Incorrect Rx statistics when packet is oversize
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+When a packet is over maximum frame size, the packet is dropped.
+However the Rx statistics, when calling `rte_eth_stats_get` incorrectly
+shows it as received.