On Mon, Oct 10, 2022 at 10:07 AM Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > > On Mon, Oct 10, 2022 at 09:56:53AM -0400, Peter Geis wrote: > > Good Morning, > > > > I've run into a bug with a new usb device when attempting to pass > > through using qemu-kvm. Another device is passed through without > > issue, and qemu spice passthrough does not exhibit the issue. The usb > > device shows up in the KVM machine, but is unusable. I'm unsure if > > this is a usbfs bug, a qemu bug, or a bug in the device driver. > > > > usb 3-6.2: usbfs: process 365671 (CPU 2/KVM) did not claim interface 0 > > before use > > usb 3-6.2: usbfs: process 365671 (CPU 2/KVM) did not claim interface 0 > > before use > > usb 3-6.2: usbfs: process 365672 (CPU 3/KVM) did not claim interface 1 > > before use > > usb 3-6.2: usbfs: process 365671 (CPU 2/KVM) did not claim interface 0 > > before use > > usb 3-6.2: usbfs: process 365672 (CPU 3/KVM) did not claim interface 0 > > before use > > usb 3-6.2: usbfs: process 365672 (CPU 3/KVM) did not claim interface 0 > > before use > > These are warnings, not bugs, although one could claim that the warnings > are caused by a bug in qemu-kvm. The bug is the device is unusable in passthrough, this is the only direction as to why. The question is which piece of software is causing it. I figure qemu is the most likely suspect, but they request bugs that are possibly in kvm start here. The cdc-acm driver is the least likely in my mind, as the other device that works also uses it. I just tested removing the other working device and only passing through the suspect device, and it still triggers the bug. So whatever the problem is, it's specific to this one device. > > > The host system is Ubuntu 22.04. > > The qemu version is as shipped: QEMU emulator version 6.2.0 (Debian > > 1:6.2+dfsg-2ubuntu6.3) > > The host kernel version is: 5.15.0-48-generic #54-Ubuntu SMP Fri Aug > > 26 13:26:29 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux > > > > The VM is HomeAssistant, running kernel 5.15.67. Issue was also > > observed on kernel version 5.10. > > Does the device work if your virtual machine has only one CPU? Just tested, this doesn't make a difference. > > Alan Stern Thanks, Peter
