Re: Usb passthrough with upstream qemu question

[George Dunlap <george.dunlap@eu.citrix.com>]

On 09/23/2013 03:46 PM, Fabio Fantoni wrote:
> I tested my latest patches about usb controllers (1-2-3) and usb
> redirection (from Spice client) support for upstream qemu and are working.
> I also tested usb passthrough (from dom0) but seems that with older
> -usbdevice paraters is not working.
> I see the qemu docs/qdev-device-use.txt and based on this I tried the
> new parameters, for example:
> device_model_args=["-device","usb-host,vendorid=0x058f,productid=0x6387"]
> With new parameters usb passthrough is working, also with new usb
> controller and also with usb redirection enabled.
> I did all tests using latest xen and qemu version (1.6).
> I think should be good to change upstream qemu parameters for usb
> passthrough on libxl with the new ones.

Yes, I think it would be better.  The main difficulty is that the libxl 
parameter is basically the old-style usbdevice parameter passed straight 
through.  To support the current libxl parameter with the new qemu would 
mean interpreting the usbdevice parameter and translating it into the 
new-style parameter.

My USB hot-plug series begins to introduce a more reasonable interface 
for USB devices. Once that's in, we can think about introducing a 
similar new interface for creating domains, that should match the new 
way of specifying devices better.  Then we could just say, "If you're 
using spice, you have to use the new interface."

Unfortunately, it's looking like the USB hot-plug series may not make it 
into 4.4 unless someone else can pick it up (or unless we slip the 
feature freeze).

  -George