systemd question

Jason D. Clinton me at
Mon May 30 20:17:49 UTC 2011

On Sun, May 15, 2011 at 17:54, Tom Horsley <horsley1953 at> wrote:
> I have occasionally wanted the ability to make some bit
> of hardware on my system disappear. Don't want linux to
> fool with it at all (but don't want to take it apart
> and yank the board either :-).
> Can I use systemctl to do this? Essentially disable
> some device unit so the system won't try to use that
> bit of hardware for anything?

In addition to the blacklist methods you've been given, there's also
the pci_stub driver which can be used after the distro is booted.

This is advantageous in that you can kick out only one of two
identical devices without having to block/unload the entire driver.

The procedure is something like this:
# echo "8086 10b9" > /sys/bus/pci/drivers/pci-stub/new_id
# echo 0000:01:00.0 > /sys/bus/pci/devices/0000:01:00.0/driver/unbind
# echo 0000:01:00.0 > /sys/bus/pci/drivers/pci-stub/bind

This is typically the method used for PCI pass-through to VM's.

I don't know how to do this for USB but I'm pretty sure there's a way
to do it as there's a UI for it exposed in libvirt-gui.

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