From edf1b618313a46680dcb6206be18fd1476cca930 Mon Sep 17 00:00:00 2001 From: Jingjing Wu Date: Fri, 30 Sep 2016 14:46:23 +0800 Subject: [PATCH] doc: add limitations for i40e PMD This patch adds "Limitations or Known issues" section for i40e PMD, including two items: 1. MPLS packet classification on X710/XL710 2. 16 Byte Descriptor cannot be used on DPDK VF 3. Link down with i40e kernel driver after DPDK application exist Signed-off-by: Jingjing Wu Acked-by: John McNamara --- doc/guides/nics/i40e.rst | 42 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) diff --git a/doc/guides/nics/i40e.rst b/doc/guides/nics/i40e.rst index 4d12b10c54..c0163fc14c 100644 --- a/doc/guides/nics/i40e.rst +++ b/doc/guides/nics/i40e.rst @@ -411,3 +411,45 @@ 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 fd_id + +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 + +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 up``. +To work around this issue, ``ethtool -s autoneg on`` should be +set first and then the link can be brought up through ``ifconfig up``. + +NOTE: requires Linux kernel i40e driver version >= 1.4.X -- 2.20.1