[systemd-devel] Utility for persistent alternative driver binding

[poma]

On 04.12.2015 15:27, poma wrote:
> On 04.12.2015 10:40, Panu Matilainen wrote:
>> Hi all,
>>
>> To follow-up on this thread from September-October:
>> http://lists.freedesktop.org/archives/systemd-devel/2015-September/034427.html
>> http://lists.freedesktop.org/archives/systemd-devel/2015-October/034551.html
>>
>> The driverctl utility has matured a bit from the earliest tyre-kicking 
>> version seen there and now lives at laiskiainen.org/git/?p=driverctl.git
>>
>> Since it has everything to do with udev this seems like a reasonable 
>> forum to advertise it a bit. Quoting from the README a bit:
>>
>>> 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.
>>  >
>>> 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-devices|grep \\*
>>> 0000:01:00.0 vfio-pci [*] (Ethernet 10G 4P X520/I350 rNDC)
>>> 0000:01:00.1 vfio-pci [*] (Ethernet 10G 4P X520/I350 rNDC)
>>>
>>> Remove the override from slot 0000:01:00.1:
>>> # driverctl unset-override 0000:01:00.1
>>
>> The other reason for posting here is: is there interest in having such a 
>> utility would find home in udev/systemd?
>>
>> Note that I'm not trying to sell you the current shell-spaghetti 
>> implementation, its mostly just a demonstration of the interface which 
>> is modeled after the various *ctl utilities in systemd. The idea is to 
>> rewrite it properly in C anyway, but at this point it'd be useful to 
>> know from style/infrastructure/etc perspective whether there's interest 
>> in having such a thing included in systemd afterall.
>>
> 
> version 0.2?
> driverctl + udevadm + add/edit/test/del udev-rules files (rather than working with files directly) = udevctl™
> 
> 

e.g.
# udevctl --driver list-devices | set-override | unset-override ...
# udevctl --admin control | hwdb | monitor ...
# udevctl --rule add | edit | test | del ...
...