Use of USB devices makes the system slow

Dear Qubes Community,

I have a new and fast device with Qubes 4.2.1, but there are problems with the use of USB devices depending on which kernel you boot the system with:

5.15: does not boot at all.

6.1: works fine overall as long as no USB devices are used. It does not matter which kernel you set for the AppVMs. As soon as a lot of data is transferred via the USB device to the AppVM and back, the mouse movement becomes slow and the system quickly becomes unresponsive for five minutes. You can stop this by unplugging the USB device from the USB port. The line with nvme timeout in dom0 under “sudo journalctl” is noticeable (the PAM unable line also appears elsewhere):

dom0 sudo[49216]: PAM unable to dlopen(/usr/lib64/security/ /usr/lib64/security/
dom0 kernel: audit: …
dom0 kernel: nvme nvme0: I/O 135 QID 5 timeout, completion polled

6.8 (kernel latest): USB devices can be used if AppVMs are operated with kernel 6.1. Suspend does not work. Nevertheless, the mouse pointer is slightly slower when using usb devices. The line in journalctl with “nvme timeout” no longer appears.

I tested this with the latest versions of each kernel series.

What could I do to come to a solution for the issue?

Do you use sys-usb?
What if you increase sys-usb memory and vCPUs?
Check the logs in sys-usb, maybe there will be more info.

1 Like

Great! I increased sys-usb memory and vCPUs. Now everything seems to work fine.