Re: [RFC PATCH 1/1] Add a usbredir kernel module to remotely connect USB devices over IP.

Jeremy White
2015-07-22T14:06:12Z

On 07/09/2015 05:06 AM, Alex Elsayed wrote:
> Alan Stern wrote:
>
>> On Mon, 6 Jul 2015, Jeremy White wrote:
>>
>>> Anything else fundamental to usbip that should inform the design of a
>>> usbredir driver? usbip appears to be based off a 2004 vintage of
>>> dummy_hcd. I'll look thoughtfully at the current dummy_hcd; please let
>>> me know if there is anything else I should consider.
>>
>> One thing that springs to mind is USB-3 streams. When dummy-hcd was
>> expanded to include USB-3, that was the major new ingredient.
>
> Another thing that comes to mind is that the USB-IF has its own official
> standard for this kind of thing now, called Media-Agnostic USB[1]. In
> November of 2014 a driver[2] was posted, followed by a second version[3],
> and it is apparently being refined inside Intel[4].
>
> [1]
> http://www.usb.org/developers/docs/devclass_docs/Media_Agnostic_USB_v1.0.zip
> [2] http://thread.gmane.org/gmane.linux.kernel/1820297
> [3] http://thread.gmane.org/gmane.linux.drivers.driver-project.devel/60498
> [4] http://article.gmane.org/gmane.linux.drivers.driver-project.devel/60757

Thanks for the pointer, Alex.

I spent some time with the spec and their proposed code. It does seem
plausible that XSpice could use a mausb/usbredir protocol converter. So
if there was a mausb kernel module, I could potentially implement
support in XSpice in user space and not need a usbredir module.

I sent an email to the two developers at Intel to ask if there had been
any further progress and if I could collaborate with them. I have not
heard back.

The MA spec is substantial and seems well thought out. But the usbredir
protocol has the virtue of being relatively mature - it's 5 years old,
with code in daily use.

At this point it seems the best path forward is to continue work on the
usbredir kernel module, which I will do unless I get some new information.

Cheers,

Jeremy