On 6/30/25 11:52 AM, David Marchand via dev wrote:
> Once upon a time, there was no driverctl, yet some crazy DPDK guys
> were using UIO for userspace packet processing.
> They came with their dpdk-devbind.py script and others started
> copy/pasting how to use it everywhere.
>
> Time has passed, and driverctl is now widespread.
> driverctl offers persistency (across reboots) of the PCI device
> configuration.
>
> Prefer it and drop documentation about dpdk-devbind.py: the DPDK
> documentation already provides plenty examples and is more likely to be
> up to date for users who want to rely on it (besides, if any modification
> in this tool was to occur, the DPDK documentation is a better place where
> to look at).
>
> Also use more standard tools like ethtool to identify the PCI device
> backing a kernel netdev.
>
> Signed-off-by: David Marchand <david.march...@redhat.com>
> ---
> Documentation/howto/dpdk.rst | 8 +++--
> Documentation/intro/install/dpdk.rst | 19 ++++++-----
> Documentation/topics/dpdk/phy.rst | 40 +++++-------------------
> Documentation/topics/dpdk/vhost-user.rst | 4 +--
> 4 files changed, 25 insertions(+), 46 deletions(-)
>
> diff --git a/Documentation/howto/dpdk.rst b/Documentation/howto/dpdk.rst
> index 73e630b07f..40a7e8fd8b 100644
> --- a/Documentation/howto/dpdk.rst
> +++ b/Documentation/howto/dpdk.rst
> @@ -228,15 +228,17 @@ described in :ref:`dpdk-testpmd`. Once compiled, run
> the application::
>
> When you finish testing, bind the vNICs back to kernel::
>
> - $ $DPDK_DIR/usertools/dpdk-devbind.py --bind=virtio-pci 0000:00:03.0
> - $ $DPDK_DIR/usertools/dpdk-devbind.py --bind=virtio-pci 0000:00:04.0
> + $ driverctl unset-override 0000:00:03.0
> + $ driverctl unset-override 0000:00:04.0
Not a problem of this patch, but the section above seems awkward and out of
place
after commit e69e4f5bac5a ("doc: Split dpdk, dpdk-advanced into multiple docs")
that moved the initial bind commands to vhost-user.rst...
>
> .. note::
>
> Valid PCI IDs must be passed in above example. The PCI IDs can be retrieved
> like so::
>
> - $ $DPDK_DIR/usertools/dpdk-devbind.py --status
> + $ driverctl -v list-devices | grep -iE '(ethernet|network)'
> + 0000:03:00.0 virtio-pci (Virtio network device)
> + 0000:04:00.0 virtio-pci (Virtio network device)
>
> More information on the dpdkvhostuserclient ports can be found in
> :doc:`/topics/dpdk/vhost-user`.
> diff --git a/Documentation/intro/install/dpdk.rst
> b/Documentation/intro/install/dpdk.rst
> index 6cff4d81e0..47d79335b2 100644
> --- a/Documentation/intro/install/dpdk.rst
> +++ b/Documentation/intro/install/dpdk.rst
> @@ -249,14 +249,17 @@ To ensure VT-d is enabled in the kernel, run::
>
> If VT-d is not enabled in the kernel, enable it now.
>
> -Once VT-d is correctly configured, load the required modules and bind the NIC
> -to the VFIO driver::
> -
> - $ modprobe vfio-pci
> - $ /usr/bin/chmod a+x /dev/vfio
> - $ /usr/bin/chmod 0666 /dev/vfio/*
> - $ $DPDK_DIR/usertools/dpdk-devbind.py --bind=vfio-pci eth1
> - $ $DPDK_DIR/usertools/dpdk-devbind.py --status
> +Once VT-d is correctly configured, bind the NIC to the VFIO driver::
> +
> + $ ethtool -i enp0s3 | grep bus-info
> + bus-info: 0000:01:00.0
> +
> + $ driverctl -v list-devices | grep -iE '(ethernet|network)'
> + 0000:01:00.0 virtio-pci (Virtio network device)
> + $ driverctl set-override 0000:01:00.0 vfio-pci
> + $ driverctl -v list-devices | grep -iE '(ethernet|network)'
> + 0000:01:00.0 vfio-pci [*] (Virtio network device)
> +
>
> Setup OVS
> ~~~~~~~~~
> diff --git a/Documentation/topics/dpdk/phy.rst
> b/Documentation/topics/dpdk/phy.rst
> index 41b2c9132f..5d9a99013e 100644
> --- a/Documentation/topics/dpdk/phy.rst
> +++ b/Documentation/topics/dpdk/phy.rst
> @@ -72,11 +72,13 @@ driver for the devices in kernel space.
> There are two different tools for binding drivers: :command:`driverctl` which
> is a generic tool for persistently configuring alternative device drivers,
> and
> :command:`dpdk-devbind` which is a DPDK-specific tool and whose changes do
> not
> -persist across reboots. In addition, there are two options available for this
> -kernel space driver - VFIO (Virtual Function I/O) and UIO (Userspace I/O) -
> -along with a number of drivers for each option. We will demonstrate examples
> of
> -both tools and will use the ``vfio-pci`` driver, which is the more secure,
> -robust driver of those available. More information can be found in the
> +persist across reboots.
> +In addition, there are two options available for this kernel space driver
> +- VFIO (Virtual Function I/O) and UIO (Userspace I/O) - along with a number
> +of drivers for each option.
> +We will demonstrate use of the generic tool and will use the ``vfio-pci``
> +driver, which is the more secure, robust driver of those available.
> +More details and information about the alternatives can be found in the
> `DPDK drivers documentation`_.
One problem with vfio-pci driver is that it can't be used by default in VMs
that have no IOMMU. Should we mention this and also refer users to the
'VFIO no-IOMMU mode' section of the DPDK docs for this use case?
>
> To list devices using :command:`driverctl`, run::
> @@ -89,34 +91,6 @@ You can then bind one or more of these devices using the
> same tool::
>
> $ driverctl set-override 0000:07:00.0 vfio-pci
>
> -Alternatively, to list devices using :command:`dpdk-devbind`, run::
> -
> - $ dpdk-devbind --status
> - Network devices using DPDK-compatible driver
> - ============================================
> - <none>
> -
> - Network devices using kernel driver
> - ===================================
> - 0000:07:00.0 'I350 Gigabit Network Connection 1521' if=enp7s0f0 drv=igb
> unused=igb_uio
> - 0000:07:00.1 'I350 Gigabit Network Connection 1521' if=enp7s0f1 drv=igb
> unused=igb_uio
> -
> - Other Network devices
> - =====================
> - ...
> -
> -Once again, you can then bind one or more of these devices using the same
> -tool::
> -
> - $ dpdk-devbind --bind=vfio-pci 0000:07:00.0
> -
> -.. versionchanged:: 2.6.0
> -
> - Open vSwitch 2.6.0 added support for DPDK 16.07, which in turn renamed the
> - former ``dpdk_nic_bind`` tool to ``dpdk-devbind``.
> -
> -For more information, refer to the `DPDK drivers documentation`_.
> -
> .. _DPDK drivers documentation:
> https://doc.dpdk.org/guides-24.11/linux_gsg/linux_drivers.html
>
> .. _dpdk-phy-multiqueue:
> diff --git a/Documentation/topics/dpdk/vhost-user.rst
> b/Documentation/topics/dpdk/vhost-user.rst
> index 20e8eb245b..76a5ec6638 100644
> --- a/Documentation/topics/dpdk/vhost-user.rst
> +++ b/Documentation/topics/dpdk/vhost-user.rst
> @@ -415,8 +415,8 @@ Setup huge pages and DPDK devices using UIO::
> $ mount -t hugetlbfs hugetlbfs /dev/hugepages # only if not already
> mounted
> $ modprobe uio
> $ insmod $DPDK_BUILD/kmod/igb_uio.ko
> - $ $DPDK_DIR/usertools/dpdk-devbind.py --status
> - $ $DPDK_DIR/usertools/dpdk-devbind.py -b igb_uio 00:03.0 00:04.0
> + $ driverctl set-override 0000:00:03.0 igb_uio
> + $ driverctl set-override 0000:00:04.0 igb_uio
>
> .. note::
>
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