qemu USB pass-through/NetBSD guest

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

Hello,
I'm trying to pass a USB device to a NetBSD guest (to ease driver
developement). I'm using:
qemu-system-x86_64 -audiodev oss,id=oss  -m 2G -accel nvmm -drive if=virtio,file=/home/bouyer/nvmm/tst-can.vnd,format=raw -netdev user,id=n1 -device virtio-net-pci,netdev=n1 -usb -device usb-host,bus=usb-bus.0,port=1,vendorid=0x1d50,productid=0x606f -chardev stdio,id=char0 -serial chardev:char0

If the guest is linux, the USB device is detected (and the appropriate
driver loaded), so the qemu part is working (at last good enough for linux),
but with a NetBSD guest this ends up with:
[    75.292264] uhub0: autoconfiguration error: device problem, disabling port 1

Any idea before I start investigating uhci ?

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--