driverctl is a device driver control utility for Linux

Description
-----------

driverctl is a tool for manipulating and inspecting the system
device driver choices.

Devices are normally assigned to their sole designated kernel driver
by default. However in some situations it may be desireable to
override that default, for example to try an older driver to
work around a regression in a driver or to try an experimental alternative
driver. Another common use-case is pass-through drivers and driver
stubs to allow userspace to drive the device, such as in case of
virtualization.

driverctl integrates with udev to support overriding
driver selection for both cold- and hotplugged devices from the
moment of discovery, but can also change already assigned drivers,
assuming they are not in use by the system. The driver overrides
created by driverctl are persistent across system reboots
by default.

License
-------

Licensed under the GNU Lesser General Public License aka LGPL v2.1.
See COPYING for details.

Source repository
-----------------

git clone https://gitlab.com/driverctl/driverctl.git

System requirements
-------------------

- udev, tested with versions >= 219 but older versions are likely
  to work as well
- kernel >= 3.16 or backported support for driver_override device
  binding path:
  https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=782a985d7af26db39e86070d28f987cad21313c0
- bash-completion (optional)

Installation
------------

"make rpm" should create a working package to be installed for those on
rpm-based distros (tested on recent Fedora and RHEL 7), others should
be able to use "make install" (but note there's no "uninstall" target)

Usage
-----

Find devices currently driven by ixgbe driver:

# driverctl -v list-devices | grep ixgbe
0000:01:00.0 ixgbe (Ethernet 10G 4P X520/I350 rNDC)
0000:01:00.1 ixgbe (Ethernet 10G 4P X520/I350 rNDC)

Change them to use the vfio-pci driver:
# driverctl set-override 0000:01:00.0 vfio-pci
# driverctl set-override 0000:01:00.1 vfio-pci

Find devices with driver overrides:
# driverctl -v list-overrides
0000:01:00.0 vfio-pci (Ethernet 10G 4P X520/I350 rNDC)
0000:01:00.1 vfio-pci (Ethernet 10G 4P X520/I350 rNDC)

Find network devices:
# driverctl list-devices network
0000:01:00.0 ixgbe
0000:01:00.1 ixgbe
0000:06:00.0 igb
0000:06:00.1 igb

Remove the override from slot 0000:01:00.1:
# driverctl unset-override 0000:01:00.1

Extras
------

In addition to the actual driverctl utility, udev rules to expose
VFIO and UIO devices on systemd level are included to make them
dependable for services. 

Since the vfio device naming is based on IOMMU groups it is rather
unpredictable on the outset: for example on my laptop the NIC at
PCI slot 0000:00:19.0 would appear as /sys/devices/virtual/vfio/3
when bound to the vfio_pci driver. To make this more discoverable,
systemd aliases are added so the device is additionally addressable
by its PCI slot name, in this example it'd be:
sys-devices-pci0000:00-0000:00:19.0-vfio.device.

Contributing etc
----------------

Patches, bug reports and other feedback are welcome via the
project page: https://gitlab.com/driverctl/driverctl