KVM - Can't use USB-device on guest system after reboot

[cornholio21]

Hello Community,
I got some problems with setting up an USB-Serial Adapter for a KVM (Windows 2008) guest system.

Adding an USB device works fine, i can add it with
qm monitor xxx
usb_add host:xxxx:xxxx
I got this:
qm> info usb
Device 0.2, Port 1, Speed 12 Mb/s, Product QEMU USB Tablet
Device 0.1, Port 2, Speed 12 Mb/s, Product QEMU USB Hub
Device 0.3, Port 2.1, Speed 480 Mb/s, Product USB-Serial Controller D

(The 0.3 is the adapter)
But I want configure, that the KVM automaticaly add the device after reboot on the host/guest system. So i wrote "hostusb: xxxx:xxxx" in /etc/qemu-server/<id>.conf.

The guest system can't find the device after reboot and I got this:
qm> info usb
Device 0.1, Port 1, Speed 12 Mb/s, Product QEMU USB Tablet
Device 0.3, Port 2, Speed 12 Mb/s, Product QEMU USB Hub
Device 0.3, Port 2.1, Speed 480 Mb/s, Product USB-Serial Controller D

I also can't understand why these 2 last have the same device id.

So, how to fix this?

Thanks a lot!

Edit:
So I have now found out, that the device id (0.2) of the Product QEMU USB Hub is changing after windows server has been booted. Before he booted the id was 0.2, but then 0.3.

 

[cornholio21]

I tried also to deactivate the USB Hub on Windows Device Manager. After activating it again, the Adapter worked fine. I noticed, that the problem comes only if i restart the vm.

Any idea how to deal with it?

 

[aglarendil]

Experiencing the same problem. Windows Server 2008 guest does not see usb device after reboot, though it is passed through according to qm monitor. Does anybody have any idea how to fix this? Is this W2008 specific?

 

[holgihero]

As i said in an other thread: the same devices not working in Win2008 did do well in WinXP and Linux so I think it is a problem in the usb subsystem of the new windowses.
Regards, Holger