[SOLVED] Pass USB Device to LXC

[xadox]

Hello All.
I am on Proxmox V7.3-6. And I want to pass a USB Device on an unprivileged Ubuntu20.04.5 LTS LXC.
The USB device is a USB adapter to read my SmartMeter:

root@proxmox:~# lsusb Bus 003 Device 002: ID 10c4:ea60 Silicon Labs CP210x UART Bridge

I followed several instructions on the net. Unfortunately this does not work properly.
The most promising seems to be this tutorial:

https://www.schreiners-it.de/proxmox/usb-geraet-in-lxc-container-unter-proxmox-7-1/

But it starts directly with the fact that no ttyACM0 is created for me. I only have ttyUSB0.
ttyUSB0 is always present regardless of whether the following command is used in one of the LXC configs:

lxc.mount.entry: /dev/bus/usb/003/006 dev/bus/usb/ none bind,optional,create=file

Then sometimes lxc.cgroup2.devices.allow is used and sometimes lxc.cgroup.devices.allow.

Any tips would be greatly appreciated.

 

[Max Carrara]

Hmm, have you tried create=dir instead of create=file already? My gut tells me create=file should be correct, but it's worth a try nevertheless.

Another thing I have noticed: Why is there a trailing / in dev/bus/usb/? Skimming the LXC docs, I can't really find anything regarding the actual path specification, so I'm not sure a trailing slash actually makes a difference or not; but maybe try something like dev/bus/usb/003/006 instead. Just for good measure.

So, the full mount entries I'd suggest you try are:

1.
lxc.mount.entry: /dev/bus/usb/003/006 dev/bus/usb/003/006 none bind,optional,create=file

2.
lxc.mount.entry: /dev/bus/usb/003/006 dev/bus/usb/003/006 none bind,optional,create=dir

Also, make sure your device has the required permissions by doing a chmod a+rw /dev/bus/usd/003/006 beforehand.

 

[xadox]

I have tested a bit more. You are totaly right.
The command should be without the ending "/":

lxc.cgroup2.devices.allow: c 189:* rwm lxc.mount.entry: /dev/bus/usb/003/002 dev/bus/usb none bind,optional,create=file

The first "/dev/bus/usb/003/002" is the mount point on the host. The Second one "dev/bus/usb" is the mount target on the lxc.
This creates the file "dev/bus/usb" on the lxc.

root@iob:/dev/bus# ls -la crw-rw-rw- 1 nobody nogroup 189, 257 Mar 14 14:51 usb

Thats working. But if I read the tutorials correctly there should be now a ttyACM0 device created on the host.
And for me thats not working. Instead I am using dev/ttyUSB0:

lxc.cgroup2.devices.allow: c 188:* rwm lxc.mount.entry: /dev/ttyUSB0 dev/ttyUSB0 none bind,optional,create=file

And with that I am able to use the USB device in the lxc.

 

[malte669966]

The Same worked with me.
Unfortunately when I Hotswap the USB Device. I loose the connection an the rights.
I receive: ls -al /dev/ttyUSB0
c--------- 0 nobody nogroup 188, 0 Aug 6 19:58 /dev/ttyUSB0

one I restart the LXC, everything is working again.

Anyone an Idea how to get the permissions Hotswap-compatible?

Rgds
Malte

 

[GleraK]

The Same worked with me.
Unfortunately when I Hotswap the USB Device. I loose the connection an the rights.
I receive: ls -al /dev/ttyUSB0
c--------- 0 nobody nogroup 188, 0 Aug 6 19:58 /dev/ttyUSB0

one I restart the LXC, everything is working again.

Anyone an Idea how to get the permissions Hotswap-compatible?

Rgds
Malte

Hi all.
I have the same problem afrter re-plug device (in 8.1.10). Is there any progress? Some settings or workaround?
Thx

 

[leesteken]

Some settings or workaround?

Work-around: add a udev rule to reboot the container on the USB plug-in event?