[libvirt-users] LXC + USB passthrough = Operation not permitted

[Daniel P. Berrange]

On Fri, Apr 11, 2014 at 05:32:28PM -0700, Filip Maj wrote:
> Hi!
> 
> First post, kind of a noobie. I've been working with LXC and libvirt for a
> few months now. Trying to do some interesting things with containers and
> Android devices :D
> Here's my entire domain definition:
> 
> <domain type='lxc'>
>   <name>oshi32134</name>
>   <uuid>xxxxx</uuid>
>   <memory unit='KiB'>3145728</memory>
>   <currentMemory unit='KiB'>3145728</currentMemory>
>   <vcpu placement='static'>1</vcpu>
>   <resource>
>     <partition>/machine</partition>
>   </resource>
>   <os>
>     <type arch='i686'>exe</type>
>     <init>/sbin/init</init>
>   </os>
>   <clock offset='utc'/>
>   <on_poweroff>destroy</on_poweroff>
>   <on_reboot>restart</on_reboot>
>   <on_crash>destroy</on_crash>
>   <devices>
>     <emulator>/usr/lib/libvirt/libvirt_lxc</emulator>
>     <filesystem type='mount' accessmode='passthrough'>
>       <source dir='/some/valid/filesystem/location'/>
>       <target dir='/'/>
>     </filesystem>
>     <filesystem type='mount' accessmode='passthrough'>
>       <source dir='/another/valid/filesystem/location'/>
>       <target dir='/mnt/android'/>
>     </filesystem>
>     <interface type='bridge'>
>       <mac address='xx:xx:xx:xx:xx:xx'/>
>       <source bridge='br1'/>
>     </interface>
>     <console type='pty'>
>       <target type='lxc' port='0'/>
>     </console>
>     <hostdev mode='capabilities' type='misc'>
>       <source>
>         <char>/dev/kvm</char>
>       </source>
>     </hostdev>
>     <hostdev mode='subsystem' type='usb' managed='yes'>
>       <source>
>         <vendor id='0x04e8'/>
>         <product id='0x6860'/>
>   </source>
>     </hostdev>
>   </devices>
> </domain>

Your config looks fine here.

> 
> Everything worked fine until I added the USB <hostdev> element. I'm
> essentially trying to get access to a physical Android device connected to
> the host from inside a container. When I go to start the container, I get
> an error about Operation not permitted. Here's the relevant bits from
> /var/log/libvirt/lxc/machine.log:
> 
> 2014-04-11 22:46:40.491+0000: starting up
> PATH=/usr/local/sbin:/usr/local/bin:/usr/bin:/usr/sbin:/sbin:/bin
> LIBVIRT_DEBUG=3 LIBVIRT_LOG_OUTPUTS=3:stderr /usr/lib/libvirt/libvirt_lxc
> --name oshi32134 --console 24 --security=none --handshake 27 --background
> --veth vnet1
> 2014-04-11 22:46:40.597+0000: 685: info : libvirt version: 1.2.2
> 2014-04-11 22:46:40.597+0000: 685: error :
> virLXCControllerSetupHostdevSubsysUSB:1390 : Unable to create device
> //var/run/libvirt/lxc/oshi32134.dev/bus/usb//002//003: Operation not
> permitted
> Unable to create device
> //var/run/libvirt/lxc/oshi32134.dev/bus/usb//002//003: Operation not
> permitted

Do you have AppArmour enabled on the machine. That seems like the
most likely thing that would result in libvirt getting that permission
error.

Regards,
Daniel
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