diff options
authorAdrien Mazarguil <>2015-04-02 11:33:43 +0200
committerThomas Monjalon <>2015-04-03 15:53:54 +0200
commit93fa8c0e1068afcecb4f0020f8815c942a74cf8b (patch)
parent72960594d3a50ee96a1146241bb8286d0394728d (diff)
doc: update mlx4 usage and dependencies
- libmlx4 and libibverbs dependencies distributed with Mellanox OFED are now also available on to make installation easier. - Document Mellanox OFED and firmware versions to use. - Add links to Mellanox and its community websites. - Add kernel modules parameters section. Signed-off-by: Adrien Mazarguil <>
1 files changed, 78 insertions, 7 deletions
diff --git a/doc/guides/nics/mlx4.rst b/doc/guides/nics/mlx4.rst
index b26c219..1216d95 100644
--- a/doc/guides/nics/mlx4.rst
+++ b/doc/guides/nics/mlx4.rst
@@ -31,8 +31,15 @@ MLX4 poll mode driver library
The MLX4 poll mode driver library (**librte_pmd_mlx4**) implements support
-for **Mellanox ConnectX-3** 10/40 Gbps adapters (EN 40, EN 10, Pro EN 40) as
-well as their virtual functions (VF) in SR-IOV context.
+for **Mellanox ConnectX-3 EN** 10/40 Gbps adapters as well as their virtual
+functions (VF) in SR-IOV context.
+Information and documentation about this family of adapters can be found on
+the `Mellanox website <>`_. Help is also provided by
+the `Mellanox community <>`_.
+There is also a `section dedicated to this poll mode driver
.. note::
@@ -78,7 +85,7 @@ Features and limitations
- Multiple MAC addresses (unicast, multicast) can be configured.
- Scattered packets are supported for TX and RX.
+.. break
- RSS hash key cannot be modified.
- Hardware counters are not implemented (they are software counters).
@@ -90,6 +97,8 @@ Configuration
Compilation options
+These options can be modified in the ``.config`` file.
- ``CONFIG_RTE_LIBRTE_MLX4_PMD`` (default **n**)
Toggle compilation of librte_pmd_mlx4 itself.
@@ -146,6 +155,30 @@ Run-time configuration
- **ethtool** operations on related kernel interfaces also affect the PMD.
+Kernel module parameters
+The **mlx4_core** kernel module has several parameters that affect the
+behavior and/or the performance of librte_pmd_mlx4. Some of them are described
+- **num_vfs** (integer or triplet, optionally prefixed by device address
+ strings)
+ Create the given number of VFs on the specified devices.
+- **log_num_mgm_entry_size** (integer)
+ Device-managed flow steering (DMFS) is required by DPDK applications. It is
+ enabled by using a negative value, the last four bits of which have a
+ special meaning.
+ - **-1**: force device-managed flow steering (DMFS).
+ - **-7**: configure optimized steering mode to improve performance with the
+ following limitation: Ethernet frames with the port MAC address as the
+ destination cannot be received, even in promiscuous mode. Additional MAC
+ addresses can still be set by ``rte_eth_dev_mac_addr_addr()``.
@@ -185,6 +218,26 @@ DPDK and must be installed separately:
- mlx4_ib: InifiniBand device driver.
- ib_uverbs: user space driver for verbs (entry point for libibverbs).
+- **Firmware update**
+ Mellanox OFED releases include firmware updates for ConnectX-3 adapters.
+ Because each release provides new features, these updates must be applied to
+ match the kernel modules and libraries they come with.
+.. note::
+ Both libraries are BSD and GPL licensed. Linux kernel modules are GPL
+ licensed.
+Currently supported by DPDK:
+- Mellanox OFED **2.4-1**.
+- Firmware version **2.33.5000** and higher.
+Getting Mellanox OFED
While these libraries and kernel modules are available on OpenFabrics
Aliance's `website <>`_ and provided by package
managers on most distributions, this PMD requires Ethernet extensions that
@@ -193,13 +246,31 @@ may not be supported at the moment (this is a work in progress).
`Mellanox OFED
includes the necessary support and should be used in the meantime. For DPDK,
-only libibverbs, libmlx4 and mlnx-ofed-kernel packages are required from
-that distribution.
+only libibverbs, libmlx4, mlnx-ofed-kernel packages and firmware updates are
+required from that distribution.
.. note::
- Both libraries are BSD and GPL licensed. Linux kernel modules are GPL
- licensed.
+ Several versions of Mellanox OFED are available. Installing the version
+ this DPDK release was developed and tested against is strongly
+ recommended. Please check the `prerequisites`_.
+Getting libibverbs and libmlx4 from
+Based on Mellanox OFED, optimized libibverbs and libmlx4 versions can be
+optionally downloaded from
+Some enhancements are done for better performance with DPDK applications and
+are not merged upstream yet.
+Since it is partly achieved by tuning compilation options to disable features
+not needed by DPDK, linking these libraries statically and avoid system-wide
+installation is the preferred method.
+Installation documentation is available from the above link.
Usage example