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PROTechThor 2020-10-18 11:44:45 +01:00
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introduction/faq.md
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@ -487,62 +487,7 @@ Enable "debug mode" in the qube's settings, either by checking the box labeled "
### I created a usbVM and assigned usb controllers to it. Now the usbVM wont boot.
This is probably because one of the controllers does not support reset.
In Qubes R2 any such errors were ignored. In Qubes R3.x they are not.
In R4.x, devices that are automatically added to sys-net and sys-usb on install but do not support FLR will be attached with the no-strict-reset option, but see the related warning in the last sentence in this answer.
A device that does not support reset is not ideal and generally should not be assigned to a VM.
Most likely the offending controller is a USB 3.0 device.
You can remove this controller from the usbVM, and see if this allows the VM to boot.
Alternatively you may be able to disable USB 3.0 in the BIOS.
If the BIOS does not have the option to disable USB 3.0, try running the following command in dom0 to [force USB 2.0 modes for the USB ports][force_usb2]:
lspci -nn | grep USB | cut -d '[' -f3 | cut -d ']' -f1 | xargs -I@ setpci -H1 -d @ d0.l=0
Errors suggesting this issue:
- in `xl dmesg` output:
(XEN) [VT-D] It's disallowed to assign 0000:00:1a.0 with shared RMRR at dbe9a000 for Dom19.
(XEN) XEN_DOMCTL_assign_device: assign 0000:00:1a.0 to dom19 failed (-1)
- during `qvm-start sys-usb`:
internal error: Unable to reset PCI device [...] no FLR, PM reset or bus reset available.
Another solution would be to set the pci_strictreset option in dom0:
- In Qubes R4.x, when attaching the PCI device to the VM (where `<BDF>` can be obtained from running `qvm-pci`):
qvm-pci attach --persistent --option no-strict-reset=true usbVM dom0:<BDF>
- In Qubes R3.x, by modifying the VM's properties:
qvm-prefs usbVM -s pci_strictreset false
These options allow the VM to ignore the error and the VM will start.
Please review the notes in the `qvm-prefs` man page and [here][assign_devices] and be aware of the potential risks.
### I assigned a PCI device to a qube, then unassigned it/shut down the qube. Why isn't the device available in dom0?
This is an intended feature.
A device which was previously assigned to a less trusted qube could attack dom0 if it were automatically reassigned there.
In order to re-enable the device in dom0, either:
* Reboot the physical machine.
or
* Go to the sysfs (`/sys/bus/pci`), find the right device, detach it from the pciback driver and attach back to the original driver. Replace `<BDF>` with your device, for example `00:1c.2`:
echo 0000:<BDF> > /sys/bus/pci/drivers/pciback/unbind
MODALIAS=`cat /sys/bus/pci/devices/0000:<BDF>/modalias`
MOD=`modprobe -R $MODALIAS | head -n 1`
echo 0000:<BDF> > /sys/bus/pci/drivers/$MOD/bind
See also [here][assign_devices].
See the [USB Troublshooting guide](/doc/usb-troubleshooting/usbVM-does-not-boot-after-creating-and-assigning-USB-controllers-to-it).
### How do I install Flash in a Debian qube?