[Qemu-discuss] USB 2.0 device not working any more

[Francesco Turco]

Hello.

I have an USB webcam I'm using under QEMU. The guest is Windows 7 
(32-bit) while the host is Gentoo Linux (64-bit). I have been using it 
for several weeks without any problem, but now it doesn't work any more 
and I don't know why. I didn't change anything. I didn't upgrade QEMU 
(1.6.1) and I didn't change the command line options. Here you are:

qemu-system-i386 -cpu host -m 1G -k it -drive 
file=Windows_7.qcow2,media=disk,index=0 -vga std -net nic -net user 
-enable-kvm -display sdl -soundhw ac97 -device usb-ehci,id=ehci -usb 
-rtc base=localtime -usbdevice tablet

The relevant options are -device usb-ehci,id=ehci -usb. That is, I'm 
enabling both USB 2.0 (EHCI) and USB 1.1 (UHCI). I used to manually add 
the webcam using: device_add usb-host,hostbus=1,hostaddr=3,id=webcam but 
if I do so it gets added as a slow USB 1.1 1.5 Mb/s device:

(qemu) info usb
  [...]
  Device 1.0, Port 1, Speed 1.5 Mb/s, Product USB Host Device

I also noticed that the "info usbhost" command works differently now, in 
that it doesn't display any more a description, such as the brand name 
(Creative):

(qemu) info usbhost
  [...]
  Bus 1, Addr 3, Port 3, Speed 480 Mb/s
  Class ef: USB device 041e:4088

From the host system:

$ lsusb  | grep Creative
Bus 001 Device 003: ID 041e:4088 Creative Technology, Ltd Live! Cam Chat 
HD [VF0700]

Why does it behave this why? Please tell me if you need other informations.

Thank you.