peripherals: 0.936
i386: 0.906
boot: 0.822
device: 0.809
ppc: 0.769
x86: 0.724
PID: 0.718
graphic: 0.702
architecture: 0.677
performance: 0.586
register: 0.559
user-level: 0.531
semantic: 0.493
files: 0.481
vnc: 0.458
hypervisor: 0.456
network: 0.435
kernel: 0.432
socket: 0.401
permissions: 0.381
virtual: 0.368
VMM: 0.356
KVM: 0.341
risc-v: 0.334
mistranslation: 0.329
debug: 0.289
TCG: 0.267
assembly: 0.256
arm: 0.229

qemu 1.3.0: usb devices shouldn't have same vendor/product ID and same serial

Boot Windows XP with
./qemu-system-i386 -device pci-ohci -device usb-tablet
and then with
./qemu-system-i386 -device pci-ohci -device usb-kbd

and you will notice, that the usb keyboard is not detected. In fact, Windows XP detects the usb tablet and loads the driver for the tablet instead of the driver for the keyboard.

The problem seems to be, that vendor and product ID and even the seriel of both the usb tablet and the usb keyboard are the same as an lsusb reveiles. Hence, Windows XP doesn't detect when you replace the tablet by a keyboard and vice versa. I didn't check other USB devices, but it seems a bad idea to me to have devices with the same vendor/product Id. I'm not aware, whether it is sufficient to change the seriel numbers of the devices.

This is a problem with ancient Linux distributions that match vendor-product in Xorg.conf as well.

This bug is more than 4 years old. Why did I even bother writing it? Is the problem still there in recent qemu versions?

Hi Sven,
  Hmm you do have a point - I wonder if this is fixed on windows by commit 5319dc7 from Gerd in November 2013 that added 'msos-desc' compat properties; but I see your point about having the same IDs

(ccing in Gerd)

Try "-device usb-tablet,serial=1234"

I see no option in Xorg.conf to match serial. Maybe there is. It is mostly undocumented, especially for some random ancient X11 snapshot the distro has.

That said the VM happens to be configured in such a way it works - keyboard and mouse are in same order on USB bus and in Xorg.conf


This is an automated cleanup. This bug report has been moved to QEMU's
new bug tracker on gitlab.com and thus gets marked as 'expired' now.
Please continue with the discussion here:

 https://gitlab.com/qemu-project/qemu/-/issues/92