[Spice-devel] [Qemu-devel] RFC: usb redirection over the network, interesting outside of spice?

[François Revol]

>>> The idea here is that a usb device connected to machine a, will be
>>> available for use by the guest os running on host b (machine b).
>>> 
>>> I'm working on this because it is something which we want / need
>>> for spice. I'm wondering if there is interest in this outside
>>> of spice ?
>>> I'm asking because at this moment in time the redirection support
>>> can probably be written in a way which abstracts the transport channel
>>> quite easily, allowing use outside of spice.
[...]
>> Not me at the moment, but unless you tunnel it inside another
>> protocol, you'd really want to look at the existing USB-over-IP
>> protocols instead of reinventing the wheel:
>> http://usbip.sourceforge.net/ (some support in Linux already IIRC)
>> (and there are others which I don't recall)
> 
> Doesn't look very useful on a quick glance.
> 
> First: Yes, we wanna embed this into other protocol(s).
> 
> Second, seems usbip is implemented using special drivers in kernel space for both sides.  We will not need special drivers on the qemu side (we just hook up the devices to the emulated hci).  On the client side using libusb looks alot more sensible than requiring kernel modules.

I recall seeing discussions about it on the libusb-devel list (CCing).

http://search.gmane.org/?query=usbip&group=gmane.comp.lib.libusb.devel.general

It's just one implementation of it, it should be possible to implement a subset of the features at least with libusb which should be enough for most devices (scanners/printers/mass storage). 

And it's better to use the same protocol anyway when possible.
This way the untunnelled version could be used from QEMU or a host using a stub driver connecting to a server using either the kernel driver or the libusb version regardless.

François.