Bug#568903: Enable USB/IP staging drivers

[Max Vozeler <xam@debian.org>]

Hi Ben,

On Fri, Feb 12, 2010 at 02:52:58AM +0000, Ben Hutchings wrote:
> On Tue, 2010-02-09 at 14:21 +0100, Max Vozeler wrote:
> > On Tue, Feb 09, 2010 at 03:21:15AM +0000, Ben Hutchings wrote:
> > > The implementation is questionable too.
> > 
> > Could you point me to related discussions or things you
> > noticed which look odd?
> 
> Comments like:
> 
> 	/*
> 	 * When removing an exported device, kernel panic sometimes occurred
> 	 * and then EIP was sk_wait_data of stub_rx thread. Is this because
> 	 * sk_wait_data returned though stub_rx thread was already finished by
> 	 * step 1?
> 	 */

Uh. I see what you mean.

This particular comment might be outdated. At least I 
cannot come up with a way the rx thread would fall over
if the connection is being shut down.

Noted to look more closely.

> > One I've been working on is remote access to hardware
> > security modules from within virtual machines.
> 
> What could possibly go wrong?!

Heh, ;-) In terms of security, surprisingly little in fact.
Those devices treat the transport as untrusted and use a
secure channel on top of USB for authentication and privacy.

> > There are still limitations that make it unsuitable 
> > for less specialized setups. Device reconnects are not
> > handeled transparently yet, for example.
> > 
> > Other limitations lie in the usbip userspace tools, the
> > most important probably being the lack of authorization
> > for access to the usbip daemon.
> 
> Apparently there are some serious problems with the protocol too.

The impression I got out of the discussion was that it is 
too limited and underdocumented, but not fundamentally flawed.

> > Hope that gives you a basis for deciding about whether 
> > to include it or keep it separate.
> 
> OK, I suppose 'staging' is probably a big enough warning label.  I think
> we can enable this for x86.  Please look for out bug reports.

OK, will do. Please don't hesitate to point out if I miss
something in the high volume of bug reports. I'll do my best
to look into problems when I notice them.

	Max