ee76bddc76
The devices of the family ConnectX may have two letters as suffix.
Such suffix is preceded with a space and the second x is lowercase:
- ConnectX-4 Lx
- ConnectX-5 Ex
- ConnectX-6 Dx
Uppercase of the device family name BlueField is also fixed.
The lists of supported devices are fixed.
Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
114 lines
4.0 KiB
ReStructuredText
114 lines
4.0 KiB
ReStructuredText
.. SPDX-License-Identifier: BSD-3-Clause
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Copyright 2019 Mellanox Technologies, Ltd
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.. include:: <isonum.txt>
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MLX5 vDPA driver
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================
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The MLX5 vDPA (vhost data path acceleration) driver library
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(**librte_pmd_mlx5_vdpa**) provides support for **Mellanox ConnectX-6**,
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**Mellanox ConnectX-6 Dx** and **Mellanox BlueField** families of
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10/25/40/50/100/200 Gb/s adapters as well as their virtual functions (VF) in
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SR-IOV context.
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.. note::
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Due to external dependencies, this driver is disabled in default
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configuration of the "make" build. It can be enabled with
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``CONFIG_RTE_LIBRTE_MLX5_VDPA_PMD=y`` or by using "meson" build system which
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will detect dependencies.
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Design
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------
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For security reasons and robustness, this driver only deals with virtual
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memory addresses. The way resources allocations are handled by the kernel,
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combined with hardware specifications that allow to handle virtual memory
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addresses directly, ensure that DPDK applications cannot access random
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physical memory (or memory that does not belong to the current process).
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The PMD can use libibverbs and libmlx5 to access the device firmware
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or directly the hardware components.
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There are different levels of objects and bypassing abilities
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to get the best performances:
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- Verbs is a complete high-level generic API
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- Direct Verbs is a device-specific API
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- DevX allows to access firmware objects
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- Direct Rules manages flow steering at low-level hardware layer
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Enabling librte_pmd_mlx5_vdpa causes DPDK applications to be linked against
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libibverbs.
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A Mellanox mlx5 PCI device can be probed by either net/mlx5 driver or vdpa/mlx5
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driver but not in parallel. Hence, the user should decide the driver by the
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``class`` parameter in the device argument list.
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By default, the mlx5 device will be probed by the net/mlx5 driver.
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Supported NICs
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--------------
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* Mellanox\ |reg| ConnectX\ |reg|-6 200G MCX654106A-HCAT (2x200G)
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* Mellanox\ |reg| ConnectX\ |reg|-6 Dx EN 100G MCX623106AN-CDAT (2x100G)
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* Mellanox\ |reg| ConnectX\ |reg|-6 Dx EN 200G MCX623105AN-VDAT (1x200G)
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* Mellanox\ |reg| BlueField SmartNIC 25G MBF1M332A-ASCAT (2x25G)
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Prerequisites
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-------------
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- Mellanox OFED version: **5.0**
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see :doc:`../../nics/mlx5` guide for more Mellanox OFED details.
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Compilation options
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~~~~~~~~~~~~~~~~~~~
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These options can be modified in the ``.config`` file.
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- ``CONFIG_RTE_LIBRTE_MLX5_VDPA_PMD`` (default **n**)
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Toggle compilation of librte_pmd_mlx5 itself.
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- ``CONFIG_RTE_IBVERBS_LINK_DLOPEN`` (default **n**)
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Build PMD with additional code to make it loadable without hard
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dependencies on **libibverbs** nor **libmlx5**, which may not be installed
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on the target system.
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In this mode, their presence is still required for it to run properly,
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however their absence won't prevent a DPDK application from starting (with
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``CONFIG_RTE_BUILD_SHARED_LIB`` disabled) and they won't show up as
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missing with ``ldd(1)``.
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It works by moving these dependencies to a purpose-built rdma-core "glue"
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plug-in which must either be installed in a directory whose name is based
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on ``CONFIG_RTE_EAL_PMD_PATH`` suffixed with ``-glue`` if set, or in a
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standard location for the dynamic linker (e.g. ``/lib``) if left to the
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default empty string (``""``).
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This option has no performance impact.
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- ``CONFIG_RTE_IBVERBS_LINK_STATIC`` (default **n**)
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Embed static flavor of the dependencies **libibverbs** and **libmlx5**
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in the PMD shared library or the executable static binary.
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.. note::
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For BlueField, target should be set to ``arm64-bluefield-linux-gcc``. This
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will enable ``CONFIG_RTE_LIBRTE_MLX5_VDPA_PMD`` and set
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``RTE_CACHE_LINE_SIZE`` to 64. Default armv8a configuration of make build and
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meson build set it to 128 then brings performance degradation.
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Run-time configuration
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~~~~~~~~~~~~~~~~~~~~~~
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- **ethtool** operations on related kernel interfaces also affect the PMD.
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- ``class`` parameter [string]
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Select the class of the driver that should probe the device.
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`vdpa` for the mlx5 vDPA driver.
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