Re: usb devices in domU

[Brook Milligan <brook%nmsu.edu@localhost>]

Thank you very much.

On Apr 16, 2015, at 1:41 AM, Manuel Bouyer wrote:
> It should be possible for a HVM guest.
> In the guest's config file:
> usb=1
> usbdevice=[ 'tablet', 'host:09fb:6001' ]
> 
> 09fb:6001 being the vendor and device ID or your USB device
> in dom0. You may need to disable drivers in dom0 so that
> your device is attached to ugen (I don't remember).

What if the device is not permanently connected?  In this particular case, Windows does not even have a driver for it; the device is detected by an application only when the app is run.  Does this mean that some controller is what needs to be passed through?

> This has worked for me at last with Xen 4.1. The above was to
> pass the Altera USBblaster to a linux guest where I could program the
> FPGA with altera's tools. It did work, but was very slow …

Does this imply that passed-through USB devices suffer performance degradation?  The one I need access to has some pretty strict speed requirements; for example, it must have USB 3.0 speeds.  Will that be possible with a dom0 intervening?

Cheers,
Brook