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Emphasized that running DPDK as non-root on Linux requires IOMMU support through vfio. -Linux Section Updates: Simplified the section to focus on: Adjusting permissions for VFIO entries in /dev and hugepage mount directories. Running DPDK applications as a user in the DPDK group. -FreeBSD Section Updates: Streamlined content to specify adjusting permissions for: Userspace-io device files in /dev, such as /dev/uio0, /dev/uio1, etc. The userspace contiguous memory device: /dev/contigmem. -Removed Sections: Detailed steps for creating user groups, binding NICs, and setting up hugepages were removed. -Overall Impact: The page now focuses more on the prerequisites for running DPDK applications without root privileges, specifically for Linux and FreeBSD, with less emphasis on detailed procedural steps. -Added a reference tag `.. _vfio_platform:` at the start of the VFIO Platform section. -Inserted a reference tag `.. _bifurcated_driver:` at the beginning of the Bifurcated Driver section. -Appended a reference tag `.. _uio:` to the UIO section. --- .../appendix/cross_compile_dpdk.rst | 37 +++ .../appendix/dpdk_meson_build_options.rst | 57 ++++ .../hugepages_different_architectures.rst | 56 ++++ .../getting_started_guide/appendix/index.rst | 18 ++ .../running_dpdk_apps_without_root.rst | 24 ++ .../appendix/vfio_advanced.rst | 301 ++++++++++++++++++ 6 files changed, 493 insertions(+) create mode 100644 doc/guides/getting_started_guide/appendix/cross_compile_dpdk.rst create mode 100644 doc/guides/getting_started_guide/appendix/dpdk_meson_build_options.rst create mode 100644 doc/guides/getting_started_guide/appendix/hugepages_different_architectures.rst create mode 100644 doc/guides/getting_started_guide/appendix/index.rst create mode 100644 doc/guides/getting_started_guide/appendix/running_dpdk_apps_without_root.rst create mode 100644 doc/guides/getting_started_guide/appendix/vfio_advanced.rst diff --git a/doc/guides/getting_started_guide/appendix/cross_compile_dpdk.rst b/doc/guides/getting_started_guide/appendix/cross_compile_dpdk.rst new file mode 100644 index 0000000000..3e4efe23a4 --- /dev/null +++ b/doc/guides/getting_started_guide/appendix/cross_compile_dpdk.rst @@ -0,0 +1,37 @@ +.. SPDX-License-Identifier: BSD-3-Clause + Copyright(c) 2010-2025 Intel Corporation. + +.. _cross_compile_dpdk: + +Cross-compiling DPDK for Different Architectures on Linux +========================================================= + +Cross-compiling DPDK for different architectures follows a similar process. Here are the general steps: + +1. **Get Compiler and Libraries**: Obtain the cross-compiler toolchain and any required libraries specific to the target architecture. + +2. **Build Using Cross-File**: Use Meson to set up the build with a cross-file specific to the target architecture, and then build with Ninja. + +Prerequisites +------------- + +- NUMA Library (if required) +- Meson and Ninja +- pkg-config for the target architecture +- Specific GNU or LLVM/Clang toolchain for the target architecture + +Cross-Compiling DPDK +-------------------- + +1. **Set Up the Cross Toolchain**: Download and extract the toolchain for the target architecture. Add it to the PATH. + +2. **Compile Any Required Libraries**: Compile libraries like NUMA if required. + +3. **Cross-Compile DPDK with Meson**: + + .. code-block:: bash + + meson setup cross-build --cross-file + ninja -C cross-build + +Refer to the specific sections for ARM64, LoongArch, and RISC-V for detailed instructions and architecture-specific considerations. \ No newline at end of file diff --git a/doc/guides/getting_started_guide/appendix/dpdk_meson_build_options.rst b/doc/guides/getting_started_guide/appendix/dpdk_meson_build_options.rst new file mode 100644 index 0000000000..6669f98371 --- /dev/null +++ b/doc/guides/getting_started_guide/appendix/dpdk_meson_build_options.rst @@ -0,0 +1,57 @@ +.. SPDX-License-Identifier: BSD-3-Clause + Copyright(c) 2010-2025 Intel Corporation. + +.. _dpdk_meson_build_options: + +DPDK Meson Build Configuration Options +====================================== + +DPDK provides a number of build configuration options that can be adjusted using the Meson build system. These options can be listed by running ``meson configure`` inside a configured build +folder. + +Changing the Build Type +----------------------- + +To change the build type from the default "release" to a regular "debug" build, +you can either: + +- Pass ``-Dbuildtype=debug`` or ``--buildtype=debug`` to meson when configuring the build folder initially. +- Run ``meson configure -Dbuildtype=debug`` inside the build folder after the initial meson run. + +Platform Options +---------------- + +The "platform" option specifies a set of configuration parameters that will be used. +The valid values are: + +- ``-Dplatform=native`` will tailor the configuration to the build machine. +- ``-Dplatform=generic`` will use configuration that works on all machines of the same architecture as the build machine. +- ``-Dplatform=`` will use configuration optimized for a particular SoC. + +Consult the "socs" dictionary in ``config/arm/meson.build`` to see which SoCs are supported. + +Overriding Platform Parameters +------------------------------ + +The values determined by the platform parameter may be overwritten. For example, +to set the ``max_lcores`` value to 256, you can either: + +- Pass ``-Dmax_lcores=256`` to meson when configuring the build folder initially. +- Run ``meson configure -Dmax_lcores=256`` inside the build folder after the initial meson run. + +Building Sample Applications +---------------------------- + +Some of the DPDK sample applications in the examples directory can be automatically built as +part of a meson build. To do so, pass a comma-separated list of the examples to build to the +``-Dexamples`` meson option as below:: + + meson setup -Dexamples=l2fwd,l3fwd build + +There is also a special value "all" to request that all example applications whose dependencies +are met on the current system are built. When ``-Dexamples=all`` is set as a meson option, +meson will check each example application to see if it can be built, and add all which can be +built to the list of tasks in the ninja build configuration file. + +For a complete list of options, run ``meson configure`` inside your configured build +folder. \ No newline at end of file diff --git a/doc/guides/getting_started_guide/appendix/hugepages_different_architectures.rst b/doc/guides/getting_started_guide/appendix/hugepages_different_architectures.rst new file mode 100644 index 0000000000..a93904fc49 --- /dev/null +++ b/doc/guides/getting_started_guide/appendix/hugepages_different_architectures.rst @@ -0,0 +1,56 @@ +.. SPDX-License-Identifier: BSD-3-Clause + Copyright(c) 2010-2025 Intel Corporation. + +.. _hugepages_different_architectures: + +Hugepages Configuration for Multiple Architectures +================================================== + +This section outlines the steps for configuring hugepages of various sizes on different architectures, an important aspect for optimizing DPDK performance. + +Hugepages on x86 Architecture +----------------------------- + +**2MB and 1G Hugepages** + +- *2MB hugepages* are commonly used on x86. +- *1G hugepages* can improve performance for large-memory applications. + +**Configuring 1G Hugepages** + +.. code-block:: bash + + # Example GRUB configuration for 1G hugepages + GRUB_CMDLINE_LINUX="default_hugepagesz=1G hugepagesz=1G hugepages=4" + +Update GRUB and reboot after making these changes. + +Hugepages on ARM Architecture +----------------------------- + +ARM supports a range of hugepage sizes, such as 64KB, 512KB, and 2MB. + +**Example Configuration** + +.. code-block:: bash + + # Setting 2MB hugepages on ARM + echo N > /sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages + +Replace 'N' with the number of pages needed. + +Other Architectures +------------------- + +Refer to architecture-specific documentation for hugepage configurations on platforms like PowerPC or MIPS. + +Boot-Time Reservation of Hugepages +---------------------------------- + +Boot-time reservation is essential for large hugepage sizes. Modify the boot loader, such as GRUB, for this purpose: + +.. code-block:: bash + + GRUB_CMDLINE_LINUX="hugepagesz=2M hugepages=512" + +Regenerate the GRUB config and reboot your system. diff --git a/doc/guides/getting_started_guide/appendix/index.rst b/doc/guides/getting_started_guide/appendix/index.rst new file mode 100644 index 0000000000..b92e3afb5a --- /dev/null +++ b/doc/guides/getting_started_guide/appendix/index.rst @@ -0,0 +1,18 @@ +.. SPDX-License-Identifier: BSD-3-Clause + Copyright(c) 2010-2025 Intel Corporation. + +.. _appendix: + +Appendix +======== + +This section covers specific guides related to DPDK. + +.. toctree:: + :maxdepth: 2 + + dpdk_meson_build_options + hugepages_different_architectures + running_dpdk_apps_without_root + vfio_advanced + cross_compile_dpdk diff --git a/doc/guides/getting_started_guide/appendix/running_dpdk_apps_without_root.rst b/doc/guides/getting_started_guide/appendix/running_dpdk_apps_without_root.rst new file mode 100644 index 0000000000..50cead324e --- /dev/null +++ b/doc/guides/getting_started_guide/appendix/running_dpdk_apps_without_root.rst @@ -0,0 +1,24 @@ +.. _running_dpdk_apps_without_root: + +Running DPDK Applications Without Root Privileges +================================================= + +It's important to note that running DPDK as non-root on Linux requires IOMMU support through vfio. + +Linux +----- +To run DPDK applications without root privileges on Linux, follow these steps: + +1. **Adjust Permissions for Specific Files and Directories**: + + - VFIO entries in ``/dev``, such as ``/dev/vfio/``, where ```` is the VFIO group to which a device used by DPDK belongs. + - The hugepage mount directory, typically ``/dev/hugepages``, or any alternative mount point configured by the user, e.g., ``/mnt/huge``, ``/mnt/huge_1G``. + +2. **Run the DPDK Application**: Execute the desired DPDK application as the user who has been added to the DPDK group. + +FreeBSD +------- +Adjust the permissions of the following files to run DPDK applications as a non-root user: + +- The userspace-io device files in ``/dev``, for example, ``/dev/uio0``, ``/dev/uio1``, and so on. +- The userspace contiguous memory device: ``/dev/contigmem``. diff --git a/doc/guides/getting_started_guide/appendix/vfio_advanced.rst b/doc/guides/getting_started_guide/appendix/vfio_advanced.rst new file mode 100644 index 0000000000..35d9e783bf --- /dev/null +++ b/doc/guides/getting_started_guide/appendix/vfio_advanced.rst @@ -0,0 +1,301 @@ +.. SPDX-License-Identifier: BSD-3-Clause + Copyright(c) 2010-2025 Intel Corporation. + +.. _vfio_advanced: + +.. |reg| unicode:: U+000AE + +VFIO Advanced +============= + + +.. contents:: Table of Contents + :local: + +.. _vfio_no_iommu_mode: + +VFIO no-IOMMU mode +------------------ + +If there is no IOMMU available on the system, VFIO can still be used, +but it has to be loaded with an additional module parameter: + +.. code-block:: console + + modprobe vfio enable_unsafe_noiommu_mode=1 + +Alternatively, one can also enable this option in an already loaded kernel module: + +.. code-block:: console + + echo 1 > /sys/module/vfio/parameters/enable_unsafe_noiommu_mode + +After that, VFIO can be used with hardware devices as usual. + +.. note:: + + It may be required to unload all VFIO related-modules before probing + the module again with ``enable_unsafe_noiommu_mode=1`` parameter. + +.. warning:: + + Since no-IOMMU mode forgoes IOMMU protection, it is inherently unsafe. + That said, it does make it possible for the user + to keep the degree of device access and programming that VFIO has, + in situations where IOMMU is not available. + +VFIO Memory Mapping Limits +-------------------------- + +For DMA mapping of either external memory or hugepages, VFIO interface is used. +VFIO does not support partial unmap of once mapped memory. Hence DPDK's memory is +mapped in hugepage granularity or system page granularity. Number of DMA +mappings is limited by kernel with user locked memory limit of a process (rlimit) +for system/hugepage memory. Another per-container overall limit applicable both +for external memory and system memory was added in kernel 5.1 defined by +VFIO module parameter ``dma_entry_limit`` with a default value of 64K. +When application is out of DMA entries, these limits need to be adjusted to +increase the allowed limit. + +Creating Virtual Functions using vfio-pci +----------------------------------------- + +Since Linux version 5.7, +the ``vfio-pci`` module supports the creation of virtual functions. +After the PF is bound to ``vfio-pci`` module, +the user can create the VFs using the ``sysfs`` interface, +and these VFs will be bound to ``vfio-pci`` module automatically. + +When the PF is bound to ``vfio-pci``, +by default it will have a randomly generated VF token. +For security reasons, this token is write only, +so the user cannot read it from the kernel directly. +To access the VFs, the user needs to create a new token, +and use it to initialize both VF and PF devices. +The tokens are in UUID format, +so any UUID generation tool can be used to create a new token. + +This VF token can be passed to DPDK by using EAL parameter ``--vfio-vf-token``. +The token will be used for all PF and VF ports within the application. + +#. Generate the VF token by uuid command + + .. code-block:: console + + 14d63f20-8445-11ea-8900-1f9ce7d5650d + +#. Load the ``vfio-pci`` module with ``enable_sriov`` parameter set + + .. code-block:: console + + sudo modprobe vfio-pci enable_sriov=1 + + Alternatively, pass the ``enable_sriov`` parameter through the ``sysfs`` if the module is already loaded or is built-in: + + .. code-block:: console + + echo 1 | sudo tee /sys/module/vfio_pci/parameters/enable_sriov + +#. Bind the PCI devices to ``vfio-pci`` driver + + .. code-block:: console + + ./usertools/dpdk-devbind.py -b vfio-pci 0000:86:00.0 + +#. Create the desired number of VF devices + + .. code-block:: console + + echo 2 > /sys/bus/pci/devices/0000:86:00.0/sriov_numvfs + +#. Start the DPDK application that will manage the PF device + + .. code-block:: console + + /app/dpdk-testpmd -l 22-25 -n 4 -a 86:00.0 \ + --vfio-vf-token=14d63f20-8445-11ea-8900-1f9ce7d5650d --file-prefix=pf -- -i + +#. Start the DPDK application that will manage the VF device + + .. code-block:: console + + /app/dpdk-testpmd -l 26-29 -n 4 -a 86:02.0 \ + --vfio-vf-token=14d63f20-8445-11ea-8900-1f9ce7d5650d --file-prefix=vf0 -- -i + +.. note:: + + Linux versions earlier than version 5.7 do not support the creation of + virtual functions within the VFIO framework. + +Troubleshooting VFIO +-------------------- + +In certain situations, using ``dpdk-devbind.py`` script +to bind a device to VFIO driver may fail. +The first place to check is the kernel messages: + +.. code-block:: console + + dmesg | tail + ... + [ 1297.875090] vfio-pci: probe of 0000:31:00.0 failed with error -22 + ... + +In most cases, the ``error -22`` indicates that the VFIO subsystem +could not be enabled because there is no IOMMU support. + +To check whether the kernel has been booted with correct parameters, +one can check the kernel command-line: + +.. code-block:: console + + cat /proc/cmdline + +Please refer to earlier sections on how to configure kernel parameters +correctly for your system. + +If the kernel is configured correctly, one also has to make sure that +the BIOS configuration has virtualization features (such as Intel\ |reg| VT-d). +There is no standard way to check if the platform is configured correctly, +so please check with your platform documentation to see if it has such features, +and how to enable them. + +In certain distributions, default kernel configuration is such that +the no-IOMMU mode is disabled altogether at compile time. +This can be checked in the boot configuration of your system: + +.. code-block:: console + + cat /boot/config-$(uname -r) | grep NOIOMMU + # CONFIG_VFIO_NOIOMMU is not set + +If ``CONFIG_VFIO_NOIOMMU`` is not enabled in the kernel configuration, +VFIO driver will not support the no-IOMMU mode, +and other alternatives (such as UIO drivers) will have to be used. + +.. _vfio_platform: + +VFIO Platform +------------- + +VFIO Platform is a kernel driver that extends capabilities of VFIO +by adding support for platform devices that reside behind an IOMMU. +Linux usually learns about platform devices directly from device tree +during boot-up phase, +unlike for example, PCI devices which have necessary information built-in. + +To make use of VFIO platform, the ``vfio-platform`` module must be loaded first: + +.. code-block:: console + + sudo modprobe vfio-platform + +.. note:: + + By default ``vfio-platform`` assumes that platform device has dedicated reset driver. + If such driver is missing or device does not require one, + this option can be turned off by setting ``reset_required=0`` module parameter. + +Afterwards platform device needs to be bound to ``vfio-platform``. +This is standard procedure requiring two steps. +First ``driver_override``, which is available inside platform device directory, +needs to be set to ``vfio-platform``: + +.. code-block:: console + + sudo echo vfio-platform > /sys/bus/platform/devices/DEV/driver_override + +Next ``DEV`` device must be bound to ``vfio-platform`` driver: + +.. code-block:: console + + sudo echo DEV > /sys/bus/platform/drivers/vfio-platform/bind + +On application startup, DPDK platform bus driver scans ``/sys/bus/platform/devices`` +searching for devices that have ``driver`` symbolic link +pointing to ``vfio-platform`` driver. +Finally, scanned devices are matched against available PMDs. +Matching is successful if either PMD name or PMD alias matches kernel driver name +or PMD name matches platform device name, all in that order. + +VFIO Platform depends on ARM/ARM64 and is usually enabled on distributions +running on these systems. +Consult your distributions documentation to make sure that is the case. + +.. _bifurcated_driver: + +Bifurcated Driver +----------------- + +PMDs which use the bifurcated driver co-exists with the device kernel driver. +On such model the NIC is controlled by the kernel, while the data +path is performed by the PMD directly on top of the device. + +Such model has the following benefits: + + - It is secure and robust, as the memory management and isolation + is done by the kernel. + - It enables the user to use legacy linux tools such as ``ethtool`` or + ``ifconfig`` while running DPDK application on the same network ports. + - It enables the DPDK application to filter only part of the traffic, + while the rest will be directed and handled by the kernel driver. + The flow bifurcation is performed by the NIC hardware. + As an example, using :ref:`flow_isolated_mode` allows to choose + strictly what is received in DPDK. + +More about the bifurcated driver can be found in +NVIDIA `bifurcated PMD +`_ presentation. + +.. _uio: + +UIO +--- + +.. warning:: + + Using UIO drivers is inherently unsafe due to this method lacking IOMMU protection, + and can only be done by root user. + +In situations where using VFIO is not an option, there are alternative drivers one can +use. +In many cases, the standard ``uio_pci_generic`` module included in the Linux kernel +can be used as a substitute for VFIO. This module can be loaded using the command: + +.. code-block:: console + + sudo modprobe uio_pci_generic + +.. note:: + + ``uio_pci_generic`` module doesn't support the creation of virtual functions. + +As an alternative to the ``uio_pci_generic``, there is the ``igb_uio`` module +which can be found in the repository `dpdk-kmods `_. +It can be loaded as shown below: + +.. code-block:: console + + sudo modprobe uio + sudo insmod igb_uio.ko + +.. note:: + + For some devices which lack support for legacy interrupts, e.g. virtual function + (VF) devices, the ``igb_uio`` module may be needed in place of ``uio_pci_generic``. + +.. note:: + + If UEFI secure boot is enabled, + the Linux kernel may disallow the use of UIO on the system. + Therefore, devices for use by DPDK should be bound to the ``vfio-pci`` kernel module + rather than any UIO-based module. + For more details see :ref:`linux_gsg_binding_kernel` below. + +.. note:: + + If the devices used for DPDK are bound to a UIO-based kernel module, + please make sure that the IOMMU is disabled or is in passthrough mode. + One can add ``intel_iommu=off`` or ``amd_iommu=off`` or ``intel_iommu=on iommu=pt`` + in GRUB command line on x86_64 systems, + or add ``iommu.passthrough=1`` on aarch64 systems. -- 2.41.0.windows.1