[Spice-devel] [Qemu-devel] usb redirection status report

[Hans de Goede]

Hi,

On 01/20/2011 09:11 PM, David Mansfield wrote:
>> H
>> i,
>>
>> On 01/20/2011 12:27 PM, Christoph Hellwig wrote:
>>> On Wed, Jan 19, 2011 at 07:15:47PM +0100, Hans de Goede wrote:
>>>> Hi All,
>>>>
>>>> As most of you know I'm working on usb redirection (making client usb
>>>> devices
>>>> accessible in guests over the network).
>>>>
>>>> I thought it would be a good idea to write a short status report.
>>>>
>>>> So fat the following has been done:
>>>>
>>>> * written and posted a network protocol for usb redir. over the network,
>>>> and send this to the list.
>>>
>
> As another late-comer, hate to ask a possibly old question but will this
> added protocol allow usb devices from arbitrary "remote" hosts to be
> redirected or only from the host running the spice client?
>

Yes, the protocol is transport independent and there will be a standalone
usb-host implementation (an tcp/ip server daemon running a machine wishing
to "share" a usb device).

> I recently tried to use the native qemu usb functionality to
> pass-through a webcam and fell flat on my face due to what others
> described as "timing issues", and was wondering if it would be possible
> to pass a USB device plugged in to the vm-host to the vm-guest using
> your new functionality, even though a third (and unrelated) host is
> running the spice client.

For vm-host to vm-guest pass through it is best to use the existing
pass through support. I'm aware of the timing issues there, and I started
with fixing those before even thinking about doing usb redirection over
the network, see:
http://lists.gnu.org/archive/html/qemu-devel/2010-11/msg02527.html

For the first patch of my patch set fixing the timing issues for local
usb redirection. Tested with multiple webcams (usb iso mode input devices)
and a set of usb speakers (usb iso mode output device).

Unfortunately there has been little response to this patch set, so I've
no idea when it will get merged.

(this seems to be the story with a lot of qemu patch sets here on the list,
like Gerd's usb descriptor rehandling patches, maybe we need to review how
qemu's patch merging processes work?)

Regards,

Hans