sys-net freezes when using LTE/WWAN via sys-usb (Qubes 3.2)

[Philipp Raschdorff]

Hello,

I have a problem when working with Qubes OS 3.2 using my built-in LTE-Card (Sierra Wireless EM7345 4G LTE) - after a while the sys-net VM freezes and when killing the sys-net Net-VM and trying to restart I get an error message.

The LTE-card is internally connected as an USB device and I'm adding the LTE-card to my sys-net via: qvm-usb -a sys-net sys-ub:3-10
LTE is working without any problem, but after a while the sys-net freezes / I've send a ping from within sys-net to keep the LTE connection alive (I thought that I might run into powersafe issues for the lte card if I don't have an active connection - but this is not helping).

When killiing the sys-net VM and trying to restart it I get an error message when the sys-net VM is trying to connect to the sys-firewall VM

[USER@dom0 ~]$ qvm-start sys-net
--> Creating volatile image: /var/lib/qubes/servicevms/sys-net/volatile.img...
--> Loading the VM (type = NetVM)...
--> Starting Qubes DB...
--> Setting Qubes DB info for the VM...
--> Updating firewall rules...
--> Starting the VM...
--> Starting the qrexec daemon...
Waiting for VM's qrexec agent......connected
--> Starting Qubes GUId...
Connecting to VM's GUI agent: .connected
--> Sending monitor layout...
--> Waiting for qubes-session...
--> Attaching network to 'sys-firewall'...
Traceback (most recent call last):
  File "/usr/bin/qvm-start", line 136, in <module>
    main()
  File "/usr/bin/qvm-start", line 120, in main
    xid = vm.start(verbose=options.verbose, preparing_dvm=options.preparing_dvm, start_guid=not options.noguid, notify_function=tray_notify_generic if options.tray else None)
  File "/usr/lib64/python2.7/site-packages/qubes/modules/005QubesNetVm.py", line 143, in start
    vm.attach_network(wait=False)
  File "/usr/lib64/python2.7/site-packages/qubes/modules/000QubesVm.py", line 1725, in attach_network
    self._format_net_dev(self.ip, self.mac, self.netvm.name))
  File "/usr/lib64/python2.7/site-packages/libvirt.py", line 530, in attachDevice
    if ret == -1: raise libvirtError ('virDomainAttachDevice() failed', dom=self)
libvirt.libvirtError: Ungültiges Argument: network device with mac 00:16:3e:5e:6c:06 already exists

If I kill all other Net-VMs (sys-firewall and sys-usb) I can then start the sys-net without an error message, but an nearly identical error message for the sys-firewall VM.

Any ideas where to look for the root cause of this problems and what might causing this problem. If i work over Wifi connection Qubes behaves rock solid.

I could try to pass through ony of my internal USB controllers to which the LTE card is connected directly to the sys-net VM to get WWAN working without using the sys-usb VM, but this would also pass through some other USB devices likes camera / fingerprint reader to the sys-net.

Also I like the concept of using a usb qube to separte my usb devices across several domains.

kind regards

- P

[Piit]

Additional information after some more testing:

I've made another test and opened two terminal windows (sys-usb and sys-firewall).
After connection to the internet via my LTE Card I've started a ping and after ~1 hour an error message appeared in sys-firewall:

[...]
64 bytes from <IP-Adress>: icmp_seq=3433 ttl=243 time=121 ms
64 bytes from <IP-Adress>: icmp_seq=3434 ttl=243 time=33.3 ms
ping: sendmsg: No buffer space available
ping: sendmsg: No buffer space available
ping: sendmsg: No buffer space available
ping: sendmsg: No buffer space available
ping: sendmsg: No buffer space available
[...]

shortly after this error message the sys-net VM freezes.
The sys-firewall and also sys-usb are still reacting via CLI, while sys-net can't be used any more and needs to be killed.

- P

[Alchemist]

I've run into an issue where mine doesn't even maintain connection for some reason (I haven't had the time to diagnose it) It connects and then disconnects from sys-net.

It also does the same for any netvm that I try and connect it to.

[PR]

On 05/07/2017 06:24 AM, Alchemist wrote:
> I've run into an issue where mine doesn't even maintain connection for some reason (I haven't had the time to diagnose it) It connects and then disconnects from sys-net.
>
> It also does the same for any netvm that I try and connect it to.

Are you connecting the LTE card via sys-usb or are you using the
LTE-card directly in the sys-net?

I tried to find out what is causing the crash in sys-net, when I attach
my internal LTE card (which is connected internall as an USB device) via
sys-usb to sys-net.
I've run ...

sudo journalctl -f

... in all VMs: sys-net, sys-usb, sys-firewall.
unfortunately I can't see anything in the terminal, when the sys-net VM
crashes. the VM and also the terminal windows which is running
journalctl freezes.
Strangely this doesn't happy when i am connected via wifi, only when
passing through my internal LTE-card via sys-net.

I'll try to pass through the whole usb controller to sys-net, to look if
it also freezes.
As I'm mostly working mobile, I need to rely on my windows installation
on my 2nd drive when working,

- P