1 .. SPDX-License-Identifier: BSD-3-Clause
2 Copyright 2012 6WIND S.A.
3 Copyright 2015 Mellanox Technologies, Ltd
5 MLX4 poll mode driver library
6 =============================
8 The MLX4 poll mode driver library (**librte_pmd_mlx4**) implements support
9 for **Mellanox ConnectX-3** and **Mellanox ConnectX-3 Pro** 10/40 Gbps adapters
10 as well as their virtual functions (VF) in SR-IOV context.
12 Information and documentation about this family of adapters can be found on
13 the `Mellanox website <http://www.mellanox.com>`_. Help is also provided by
14 the `Mellanox community <http://community.mellanox.com/welcome>`_.
16 There is also a `section dedicated to this poll mode driver
17 <http://www.mellanox.com/page/products_dyn?product_family=209&mtag=pmd_for_dpdk>`_.
21 Due to external dependencies, this driver is disabled by default. It must
22 be enabled manually by setting ``CONFIG_RTE_LIBRTE_MLX4_PMD=y`` and
25 Implementation details
26 ----------------------
28 Most Mellanox ConnectX-3 devices provide two ports but expose a single PCI
29 bus address, thus unlike most drivers, librte_pmd_mlx4 registers itself as a
30 PCI driver that allocates one Ethernet device per detected port.
32 For this reason, one cannot white/blacklist a single port without also
33 white/blacklisting the others on the same device.
35 Besides its dependency on libibverbs (that implies libmlx4 and associated
36 kernel support), librte_pmd_mlx4 relies heavily on system calls for control
37 operations such as querying/updating the MTU and flow control parameters.
39 For security reasons and robustness, this driver only deals with virtual
40 memory addresses. The way resources allocations are handled by the kernel
41 combined with hardware specifications that allow it to handle virtual memory
42 addresses directly ensure that DPDK applications cannot access random
43 physical memory (or memory that does not belong to the current process).
45 This capability allows the PMD to coexist with kernel network interfaces
46 which remain functional, although they stop receiving unicast packets as
47 long as they share the same MAC address.
49 Compiling librte_pmd_mlx4 causes DPDK to be linked against libibverbs.
57 These options can be modified in the ``.config`` file.
59 - ``CONFIG_RTE_LIBRTE_MLX4_PMD`` (default **n**)
61 Toggle compilation of librte_pmd_mlx4 itself.
63 - ``CONFIG_RTE_LIBRTE_MLX4_DLOPEN_DEPS`` (default **n**)
65 Build PMD with additional code to make it loadable without hard
66 dependencies on **libibverbs** nor **libmlx4**, which may not be installed
69 In this mode, their presence is still required for it to run properly,
70 however their absence won't prevent a DPDK application from starting (with
71 ``CONFIG_RTE_BUILD_SHARED_LIB`` disabled) and they won't show up as
72 missing with ``ldd(1)``.
74 It works by moving these dependencies to a purpose-built rdma-core "glue"
75 plug-in which must either be installed in a directory whose name is based
76 on ``CONFIG_RTE_EAL_PMD_PATH`` suffixed with ``-glue`` if set, or in a
77 standard location for the dynamic linker (e.g. ``/lib``) if left to the
78 default empty string (``""``).
80 This option has no performance impact.
82 - ``CONFIG_RTE_LIBRTE_MLX4_DEBUG`` (default **n**)
84 Toggle debugging code and stricter compilation flags. Enabling this option
85 adds additional run-time checks and debugging messages at the cost of
93 A list of directories in which to search for the rdma-core "glue" plug-in,
94 separated by colons or semi-colons.
96 Only matters when compiled with ``CONFIG_RTE_LIBRTE_MLX4_DLOPEN_DEPS``
97 enabled and most useful when ``CONFIG_RTE_EAL_PMD_PATH`` is also set,
98 since ``LD_LIBRARY_PATH`` has no effect in this case.
100 Run-time configuration
101 ~~~~~~~~~~~~~~~~~~~~~~
103 - librte_pmd_mlx4 brings kernel network interfaces up during initialization
104 because it is affected by their state. Forcing them down prevents packets
107 - **ethtool** operations on related kernel interfaces also affect the PMD.
109 - ``port`` parameter [int]
111 This parameter provides a physical port to probe and can be specified multiple
112 times for additional ports. All ports are probed by default if left
115 Kernel module parameters
116 ~~~~~~~~~~~~~~~~~~~~~~~~
118 The **mlx4_core** kernel module has several parameters that affect the
119 behavior and/or the performance of librte_pmd_mlx4. Some of them are described
122 - **num_vfs** (integer or triplet, optionally prefixed by device address
125 Create the given number of VFs on the specified devices.
127 - **log_num_mgm_entry_size** (integer)
129 Device-managed flow steering (DMFS) is required by DPDK applications. It is
130 enabled by using a negative value, the last four bits of which have a
133 - **-1**: force device-managed flow steering (DMFS).
134 - **-7**: configure optimized steering mode to improve performance with the
135 following limitation: VLAN filtering is not supported with this mode.
136 This is the recommended mode in case VLAN filter is not needed.
141 - CRC stripping is supported by default and always reported as "true".
142 The ability to enable/disable CRC stripping requires OFED version
143 4.3-1.5.0.0 and above or rdma-core version v18 and above.
145 - TSO (Transmit Segmentation Offload) is supported in OFED version
151 This driver relies on external libraries and kernel drivers for resources
152 allocations and initialization. The following dependencies are not part of
153 DPDK and must be installed separately:
155 - **libibverbs** (provided by rdma-core package)
157 User space verbs framework used by librte_pmd_mlx4. This library provides
158 a generic interface between the kernel and low-level user space drivers
161 It allows slow and privileged operations (context initialization, hardware
162 resources allocations) to be managed by the kernel and fast operations to
163 never leave user space.
165 - **libmlx4** (provided by rdma-core package)
167 Low-level user space driver library for Mellanox ConnectX-3 devices,
168 it is automatically loaded by libibverbs.
170 This library basically implements send/receive calls to the hardware
175 They provide the kernel-side verbs API and low level device drivers that
176 manage actual hardware initialization and resources sharing with user
179 Unlike most other PMDs, these modules must remain loaded and bound to
182 - mlx4_core: hardware driver managing Mellanox ConnectX-3 devices.
183 - mlx4_en: Ethernet device driver that provides kernel network interfaces.
184 - mlx4_ib: InifiniBand device driver.
185 - ib_uverbs: user space driver for verbs (entry point for libibverbs).
187 - **Firmware update**
189 Mellanox OFED releases include firmware updates for ConnectX-3 adapters.
191 Because each release provides new features, these updates must be applied to
192 match the kernel modules and libraries they come with.
196 Both libraries are BSD and GPL licensed. Linux kernel modules are GPL
199 Depending on system constraints and user preferences either RDMA core library
200 with a recent enough Linux kernel release (recommended) or Mellanox OFED,
201 which provides compatibility with older releases.
203 Current RDMA core package and Linux kernel (recommended)
204 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
206 - Minimal Linux kernel version: 4.14.
207 - Minimal RDMA core version: v15 (see `RDMA core installation documentation`_).
209 .. _`RDMA core installation documentation`: https://raw.githubusercontent.com/linux-rdma/rdma-core/master/README.md
211 .. _Mellanox_OFED_as_a_fallback:
213 Mellanox OFED as a fallback
214 ~~~~~~~~~~~~~~~~~~~~~~~~~~~
216 - `Mellanox OFED`_ version: **4.3**.
217 - firmware version: **2.42.5000** and above.
219 .. _`Mellanox OFED`: http://www.mellanox.com/page/products_dyn?product_family=26&mtag=linux_sw_drivers
223 Several versions of Mellanox OFED are available. Installing the version
224 this DPDK release was developed and tested against is strongly
225 recommended. Please check the `prerequisites`_.
227 Installing Mellanox OFED
228 ^^^^^^^^^^^^^^^^^^^^^^^^
230 1. Download latest Mellanox OFED.
232 2. Install the required libraries and kernel modules either by installing
233 only the required set, or by installing the entire Mellanox OFED:
237 .. code-block:: console
239 ./mlnxofedinstall --dpdk --upstream-libs
241 For SR-IOV hypervisors use:
243 .. code-block:: console
245 ./mlnxofedinstall --dpdk --upstream-libs --enable-sriov --hypervisor
247 For SR-IOV virtual machine use:
249 .. code-block:: console
251 ./mlnxofedinstall --dpdk --upstream-libs --guest
253 3. Verify the firmware is the correct one:
255 .. code-block:: console
259 4. Set all ports links to Ethernet, follow instructions on the screen:
261 .. code-block:: console
265 5. Continue with :ref:`section 2 of the Quick Start Guide <QSG_2>`.
270 * Mellanox(R) ConnectX(R)-3 Pro 40G MCX354A-FCC_Ax (2*40G)
277 1. Set all ports links to Ethernet
279 .. code-block:: console
281 PCI=<NIC PCI address>
282 echo eth > "/sys/bus/pci/devices/$PCI/mlx4_port0"
283 echo eth > "/sys/bus/pci/devices/$PCI/mlx4_port1"
287 If using Mellanox OFED one can permanently set the port link
288 to Ethernet using connectx_port_config tool provided by it.
289 :ref:`Mellanox_OFED_as_a_fallback`:
293 2. In case of bare metal or hypervisor, configure optimized steering mode
294 by adding the following line to ``/etc/modprobe.d/mlx4_core.conf``:
296 .. code-block:: console
298 options mlx4_core log_num_mgm_entry_size=-7
302 If VLAN filtering is used, set log_num_mgm_entry_size=-1.
303 Performance degradation can occur on this case.
305 3. Restart the driver:
307 .. code-block:: console
309 /etc/init.d/openibd restart
313 .. code-block:: console
315 service openibd restart
317 4. Compile DPDK and you are ready to go. See instructions on
318 :ref:`Development Kit Build System <Development_Kit_Build_System>`
323 1. Verify the optimized steering mode is configured:
325 .. code-block:: console
327 cat /sys/module/mlx4_core/parameters/log_num_mgm_entry_size
329 2. Use the CPU near local NUMA node to which the PCIe adapter is connected,
330 for better performance. For VMs, verify that the right CPU
331 and NUMA node are pinned according to the above. Run:
333 .. code-block:: console
337 to identify the NUMA node to which the PCIe adapter is connected.
339 3. If more than one adapter is used, and root complex capabilities allow
340 to put both adapters on the same NUMA node without PCI bandwidth degradation,
341 it is recommended to locate both adapters on the same NUMA node.
342 This in order to forward packets from one to the other without
343 NUMA performance penalty.
345 4. Disable pause frames:
347 .. code-block:: console
349 ethtool -A <netdev> rx off tx off
351 5. Verify IO non-posted prefetch is disabled by default. This can be checked
352 via the BIOS configuration. Please contact you server provider for more
353 information about the settings.
357 On some machines, depends on the machine integrator, it is beneficial
358 to set the PCI max read request parameter to 1K. This can be
359 done in the following way:
361 To query the read request size use:
363 .. code-block:: console
365 setpci -s <NIC PCI address> 68.w
367 If the output is different than 3XXX, set it by:
369 .. code-block:: console
371 setpci -s <NIC PCI address> 68.w=3XXX
373 The XXX can be different on different systems. Make sure to configure
374 according to the setpci output.
376 6. To minimize overhead of searching Memory Regions:
378 - '--socket-mem' is recommended to pin memory by predictable amount.
379 - Configure per-lcore cache when creating Mempools for packet buffer.
380 - Refrain from dynamically allocating/freeing memory in run-time.
385 This section demonstrates how to launch **testpmd** with Mellanox ConnectX-3
386 devices managed by librte_pmd_mlx4.
388 #. Load the kernel modules:
390 .. code-block:: console
392 modprobe -a ib_uverbs mlx4_en mlx4_core mlx4_ib
394 Alternatively if MLNX_OFED is fully installed, the following script can
397 .. code-block:: console
399 /etc/init.d/openibd restart
403 User space I/O kernel modules (uio and igb_uio) are not used and do
404 not have to be loaded.
406 #. Make sure Ethernet interfaces are in working order and linked to kernel
407 verbs. Related sysfs entries should be present:
409 .. code-block:: console
411 ls -d /sys/class/net/*/device/infiniband_verbs/uverbs* | cut -d / -f 5
415 .. code-block:: console
422 #. Optionally, retrieve their PCI bus addresses for whitelisting:
424 .. code-block:: console
427 for intf in eth2 eth3 eth4 eth5;
429 (cd "/sys/class/net/${intf}/device/" && pwd -P);
432 sed -n 's,.*/\(.*\),-w \1,p'
436 .. code-block:: console
445 There are only two distinct PCI bus addresses because the Mellanox
446 ConnectX-3 adapters installed on this system are dual port.
448 #. Request huge pages:
450 .. code-block:: console
452 echo 1024 > /sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages/nr_hugepages
454 #. Start testpmd with basic parameters:
456 .. code-block:: console
458 testpmd -l 8-15 -n 4 -w 0000:83:00.0 -w 0000:84:00.0 -- --rxq=2 --txq=2 -i
462 .. code-block:: console
465 EAL: PCI device 0000:83:00.0 on NUMA socket 1
466 EAL: probe driver: 15b3:1007 librte_pmd_mlx4
467 PMD: librte_pmd_mlx4: PCI information matches, using device "mlx4_0" (VF: false)
468 PMD: librte_pmd_mlx4: 2 port(s) detected
469 PMD: librte_pmd_mlx4: port 1 MAC address is 00:02:c9:b5:b7:50
470 PMD: librte_pmd_mlx4: port 2 MAC address is 00:02:c9:b5:b7:51
471 EAL: PCI device 0000:84:00.0 on NUMA socket 1
472 EAL: probe driver: 15b3:1007 librte_pmd_mlx4
473 PMD: librte_pmd_mlx4: PCI information matches, using device "mlx4_1" (VF: false)
474 PMD: librte_pmd_mlx4: 2 port(s) detected
475 PMD: librte_pmd_mlx4: port 1 MAC address is 00:02:c9:b5:ba:b0
476 PMD: librte_pmd_mlx4: port 2 MAC address is 00:02:c9:b5:ba:b1
477 Interactive-mode selected
478 Configuring Port 0 (socket 0)
479 PMD: librte_pmd_mlx4: 0x867d60: TX queues number update: 0 -> 2
480 PMD: librte_pmd_mlx4: 0x867d60: RX queues number update: 0 -> 2
481 Port 0: 00:02:C9:B5:B7:50
482 Configuring Port 1 (socket 0)
483 PMD: librte_pmd_mlx4: 0x867da0: TX queues number update: 0 -> 2
484 PMD: librte_pmd_mlx4: 0x867da0: RX queues number update: 0 -> 2
485 Port 1: 00:02:C9:B5:B7:51
486 Configuring Port 2 (socket 0)
487 PMD: librte_pmd_mlx4: 0x867de0: TX queues number update: 0 -> 2
488 PMD: librte_pmd_mlx4: 0x867de0: RX queues number update: 0 -> 2
489 Port 2: 00:02:C9:B5:BA:B0
490 Configuring Port 3 (socket 0)
491 PMD: librte_pmd_mlx4: 0x867e20: TX queues number update: 0 -> 2
492 PMD: librte_pmd_mlx4: 0x867e20: RX queues number update: 0 -> 2
493 Port 3: 00:02:C9:B5:BA:B1
494 Checking link statuses...
495 Port 0 Link Up - speed 10000 Mbps - full-duplex
496 Port 1 Link Up - speed 40000 Mbps - full-duplex
497 Port 2 Link Up - speed 10000 Mbps - full-duplex
498 Port 3 Link Up - speed 40000 Mbps - full-duplex