Xen project Mailing List

On 06/02/2013 03:05 PM, David Sutton wrote:

I 'cheated' in that I just passed one of the USB controllers through to
my windows domU, then use a pair of USB headphones that I switch from
one port to another, depending on which VM i'm currently using. Not had
any issues with it that way.

Yes, I was doing that for my keyboard and mouse passthrough to domU, but found that PCI passthrough on USB controllers was a bit hit-and-miss - they often wouldn't come up properly when rebooting the VM. I switched to using USB passthrough because of that, and since my audio PCI passthough wasn't entirely trouble-free, I thought I'd try the seemingly more stable USB passthrough for that purpose.

Gordan

Hello Gordan,

I haven't tried USB passthrough on Xen yet, and I admit that I haven't thought of trying, really, only because I've had such a poor experience with it in the past on ESXi. When I first undertook the task of getting audio output from my VM (along with Keyboard/Mouse input!) USB passthrough was my first idea... but it was just all crackly and terrible. I was using a quality device, too---a Sound Blaster X-Fi---I tried others, too, but that didn't seem to matter.

The next stop on getting this to work was instead to pass through a USB controller, but the board I was using didn't play nice when I did that. The onboard USB2's were all hung off the PCI bus, which meant ESXi wouldn't let me pass them at all, and the USB3 controllers just flat out didn't work.

I tried a commercial USB-port sharing product called USB Redirector. It worked very well for both Audio and Inputs. No latency, no crackling.... but at about the cost of $40 per device... Since I needed twelve devices, I scrapped that idea.

The USB/IP project shows promise, but at the time wasn't far along enough for me to consider using it. I think that now, though, it might be worth investigating. If you want to work this out with software, I'd actually suggest looking into that the most!

I'm admittedly a little puzzled by the fact that you're having problems with PCI passthrough of a USB controller, especially because you have an Intel-based system... I always remember reports of that "just working."

If you've got any more PCIe slots on your system, a USB3 add-in card might be the way to go... just make sure it doesn't take power from a molex plug :P

Best Regards,

Andrew Bobulsky

Re: [Xen-users] USB Audio Passthrough