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Diffstat (limited to 'doc/guides/nics/mlx5.rst')
| -rw-r--r-- | doc/guides/nics/mlx5.rst | 65 |
1 files changed, 52 insertions, 13 deletions
diff --git a/doc/guides/nics/mlx5.rst b/doc/guides/nics/mlx5.rst index f9558da8..0e6e525c 100644 --- a/doc/guides/nics/mlx5.rst +++ b/doc/guides/nics/mlx5.rst @@ -105,10 +105,12 @@ Limitations ----------- - Inner RSS for VXLAN frames is not supported yet. -- Port statistics through software counters only. Flow statistics are - supported by hardware counters. - Hardware checksum RX offloads for VXLAN inner header are not supported yet. -- Forked secondary process not supported. +- For secondary process: + + - Forked secondary process not supported. + - All mempools must be initialized before rte_eth_dev_start(). + - Flow pattern without any specific vlan will match for vlan packets as well: When VLAN spec is not specified in the pattern, the matching rule will be created with VLAN as a wild card. @@ -129,11 +131,22 @@ Limitations - A multi segment packet must have less than 6 segments in case the Tx burst function is set to multi-packet send or Enhanced multi-packet send. Otherwise it must have less than 50 segments. -- Count action for RTE flow is only supported in Mellanox OFED 4.2. +- Count action for RTE flow is **only supported in Mellanox OFED**. - Flows with a VXLAN Network Identifier equal (or ends to be equal) to 0 are not supported. - VXLAN TSO and checksum offloads are not supported on VM. +Statistics +---------- + +MLX5 supports various of methods to report statistics: + +Port statistics can be queried using ``rte_eth_stats_get()``. The port statistics are through SW only and counts the number of packets received or sent successfully by the PMD. + +Extended statistics can be queried using ``rte_eth_xstats_get()``. The extended statistics expose a wider set of counters counted by the device. The extended port statistics counts the number of packets received or sent successfully by the port. As Mellanox NICs are using the :ref:`Bifurcated Linux Driver <linux_gsg_linux_drivers>` those counters counts also packet received or sent by the Linux kernel. The counters with ``_phy`` suffix counts the total events on the physical port, therefore not valid for VF. + +Finally per-flow statistics can by queried using ``rte_flow_query`` when attaching a count action for specific flow. The flow counter counts the number of packets received successfully by the port and match the specific flow. + Configuration ------------- @@ -146,6 +159,24 @@ These options can be modified in the ``.config`` file. Toggle compilation of librte_pmd_mlx5 itself. +- ``CONFIG_RTE_LIBRTE_MLX5_DLOPEN_DEPS`` (default **n**) + + Build PMD with additional code to make it loadable without hard + dependencies on **libibverbs** nor **libmlx5**, which may not be installed + on the target system. + + In this mode, their presence is still required for it to run properly, + however their absence won't prevent a DPDK application from starting (with + ``CONFIG_RTE_BUILD_SHARED_LIB`` disabled) and they won't show up as + missing with ``ldd(1)``. + + It works by moving these dependencies to a purpose-built rdma-core "glue" + plug-in, which must either be installed in ``CONFIG_RTE_EAL_PMD_PATH`` if + set, or in a standard location for the dynamic linker (e.g. ``/lib``) if + left to the default empty string (``""``). + + This option has no performance impact. + - ``CONFIG_RTE_LIBRTE_MLX5_DEBUG`` (default **n**) Toggle debugging code and stricter compilation flags. Enabling this option @@ -163,6 +194,15 @@ These options can be modified in the ``.config`` file. Environment variables ~~~~~~~~~~~~~~~~~~~~~ +- ``MLX5_GLUE_PATH`` + + A list of directories in which to search for the rdma-core "glue" plug-in, + separated by colons or semi-colons. + + Only matters when compiled with ``CONFIG_RTE_LIBRTE_MLX5_DLOPEN_DEPS`` + enabled and most useful when ``CONFIG_RTE_EAL_PMD_PATH`` is also set, + since ``LD_LIBRARY_PATH`` has no effect in this case. + - ``MLX5_PMD_ENABLE_PADDING`` Enables HW packet padding in PCI bus transactions. @@ -253,8 +293,9 @@ Run-time configuration Enhanced MPS supports hybrid mode - mixing inlined packets and pointers in the same descriptor. - This option cannot be used in conjunction with ``tso`` below. When ``tso`` - is set, ``txq_mpw_en`` is disabled. + This option cannot be used with certain offloads such as ``DEV_TX_OFFLOAD_TCP_TSO, + DEV_TX_OFFLOAD_VXLAN_TNL_TSO, DEV_TX_OFFLOAD_GRE_TNL_TSO, DEV_TX_OFFLOAD_VLAN_INSERT``. + When those offloads are requested the MPS send function will not be used. It is currently only supported on the ConnectX-4 Lx and ConnectX-5 families of adapters. Enabled by default. @@ -275,17 +316,15 @@ Run-time configuration Effective only when Enhanced MPS is supported. The default value is 256. -- ``tso`` parameter [int] - - A nonzero value enables hardware TSO. - When hardware TSO is enabled, packets marked with TCP segmentation - offload will be divided into segments by the hardware. Disabled by default. - - ``tx_vec_en`` parameter [int] A nonzero value enables Tx vector on ConnectX-5 only NIC if the number of global Tx queues on the port is lesser than MLX5_VPMD_MIN_TXQS. + This option cannot be used with certain offloads such as ``DEV_TX_OFFLOAD_TCP_TSO, + DEV_TX_OFFLOAD_VXLAN_TNL_TSO, DEV_TX_OFFLOAD_GRE_TNL_TSO, DEV_TX_OFFLOAD_VLAN_INSERT``. + When those offloads are requested the MPS send function will not be used. + Enabled by default on ConnectX-5. - ``rx_vec_en`` parameter [int] @@ -367,7 +406,7 @@ RMDA Core with Linux Kernel Mellanox OFED ^^^^^^^^^^^^^ -- Mellanox OFED version: **4.2**. +- Mellanox OFED version: **4.2, 4.3**. - firmware version: - ConnectX-4: **12.21.1000** and above. |