after using 3.1 and 3.2 in production on my primary laptop
(Lenovo X220), and having used that machine to test Qubes since R2,
I now have the need to make my built in camera available in an App VM (I choose untrusted, but may a dedicated one later on).
However, I am failing to pass through the
USB controller to the App VM. This
may never have worked with Qubes 3.x (didn't need it so far), but I definitely tested this in the 2.x days.
Since it was experimental(?) at the time, I chose not to install
a dedicated USB VM, so by default both USB controllers are
assigned to Dom0. This is what my system/hardware looks like
Please note that this is Qubes R3.2!!
lspci (in Dom0):
00:1a.0 USB controller: Intel Corporation 6 Series/C200 Series Chipset Family USB Enhanced Host Controller #2 (rev 04)
00:1d.0 USB controller: Intel Corporation 6 Series/C200 Series Chipset Family USB Enhanced Host Controller #1 (rev 04)
lsusb (in Dom0):
Bus 002 Device 003: ID 0bdb:1911 Ericsson Business Mobile Networks BV
Bus 002 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 003: ID 04f2:b217 Chicony Electronics Co., Ltd Lenovo Integrated Camera (0.3MP)
Bus 001 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Output of 'readlink /sys/bus/usb/devices/usb1'
I assumed that the path of least resistance would be to attach
the USB controller with pci ID 00:1a.0 to my AppVM (untrusted).
qvm-pci -a untrusted 00:1a.0
qvm-pci -l untrusted
However, as apparently often seen (mailing list, FAQ), at that
point I fail to start the AppVM:
[user@dom0 ~]$ qvm-start untrusted
--> Creating volatile image: /var/lib/qubes/appvms/untrusted/volatile.img...
--> Loading the VM (type = AppVM)...
Traceback (most recent call last):
File "/usr/bin/qvm-start", line 136, in <module>
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/000QubesVm.py", line 1979, in start
File "/usr/lib64/python2.7/site-packages/libvirt.py", line 1059, in createWithFlags
if ret == -1: raise libvirtError ('virDomainCreateWithFlags() failed', dom=self)
libvirt.libvirtError: internal error: libxenlight failed to create new domain 'untrusted'
And xl dmesg shows:
XEN) [VT-D] It's disallowed to assign 0000:00:1a.0 with shared RMRR at da8d5000 for Dom5.
(XEN) XEN_DOMCTL_assign_device: assign 0000:00:1a.0 to dom5 failed (-1)
Further, pci ID 00:1a.0 still shows up in dom0.
In the context of dedicated USB VMs there is a FAQ pertaining to this,
and clearly there are several github issues related to this. However,
qvm-prefs untrusted -s pci_strictreset false
I get exactly the same error (AppVM untrusted fails to start). I tried
the trick resetting USB to 2.0 (though given the age of the machine
I am not even sure that this is a 3.0 hub/device); again no effect --
as far as I can tell identical error.
Yesterday too late I found some discussions from 2015 in a Xen mailing list, where someone eventually succeeded using several options, but
I don't know how to set these in Qubes (via qvm-prefs??).
I should add that i tried again after rebooting as well, but no
change. So, I am puzzled as I know that this worked in Qubes 2.x.
Am I missing some small print in my attempts and/or in what order
should I try the tricks that might remedy this?
I guess I could try setting up a USB VM, but I assume I would run
into exactly the same issue. And aside from the need to assign the
camera, I don't exactly have a use scenario for a dedicated USB VM
on that machine.
Help appreciated, thanks in advance!