USB virt 2.6 split driver patch series

[harry <harry@hebutterworth.freeserve.co.uk>]

I'm about to post a series of 17 patches which implement the xenidc
interdomain communications code and the USB split driver built on the
xenidc code.

These patches have been tested against today's unstable for the i386
build and can be successfully used to create a filesystem on and mount a
USB key.

Currently the code requires swiotlb=force and there are a few issues
which need to be addressed:

o - The USB protocol requires stalling the URB queue during error
conditions.  This isn't done correctly yet which makes the code unsafe
for write access during error recovery.  The 2.4 code had this problem
as well I only discovered it recently.

o - The USB-specific part of the interdomain protocol is using polling
for device discovery which is inefficient.  This is the same strategy as
the 2.4 code.

o - The resource pools are currently only allocating the minimum
resources required to avoid deadlock so performance will be resource
constrained.  This can be fixed either by implementing a larger static
resource allocation or improving the buffer_resource_provider to
implement a dynamic shared resource pool.  Either is fairly easy.

o - I've reformatted all the code to the kernel coding style using
Lindent and not attempted to improve it after that.  Some of the
formatting needs to be improved.

Now that it's basically working, if possible, I'd like to get the code
into the tree and work on it there.

Any feedback on the patches, particularly on what it's going to take to
get the code into the tree, would be most welcome.

Harry.