Xbox controller on Linux with xpadneo with onboard Intel AX210

Most basic steps are detailed in the ArchWiki, here are just some more details, which helped me.

ArchWiki section: Gamepad - ArchWiki

My bluetooth adapter uses the same IOMMU groups as a lot of other devices, so VFIO wasn’t usable.

1. Install xpadneo-dkms

E.g. on Arch with yay:

yay xpadneo-dkms

2. Install and setup win10/11 VM in QEMU/KVM

Some changes required for USB passthrough to work. Source reddit comment Other Reddit thread

In the xml update the schema and add capability to the end:

<domain xmlns:qemu="http://libvirt.org/schemas/domain/qemu/1.0" type="kvm">  
  <devices>    
...    
  </devices>    
  <qemu:capabilities>    
<qemu:del capability="usb-host.hostdevice"/>    
  </qemu:capabilities>    
</domain>

Then Add hardware -> USB Host device -> The bluetooth adapter

3. Pair devices in Windows

Push the connect button, pair controller the normal way

Shut down the VM

4. Pair devices in Linux

Push the connect button, pair controller the normal way

Now it works!