[RFC] 9p Virtualization Transports

[Eric Van Hensbergen <ericvh@gmail.com>]

This patch set contains a set of virtualization transports for the 9p file
system intended to provide a mechanism for guests to access a portion of the
hosts name space without having to go through a virtualized network.  

Shared memory based transports are provided for lguest using a variation of 
the lguest console code and for KVM using a synthetic PCI device.  The patches
to the qemu portion of the latter will be posted to the kvm-devel list later
today.  

Also provided is a much older hack implementation which was used on XenPPC to 
communicated between Dom0 and DomU as part of the PROSE 
(http://www.research.ibm.com/prose) and Libra projects.  It is not our intent
to push the Xen shared memory transport into the kernel, but we are providing 
it in this patch-set for historical reference.

The lguest and kvm transports are functional, but we are still working out
remaining bugs and need to spend some time focusing on performance issues.
I wanted to send out this "preview" patch set to the community to solicit
ideas on things we can do differently/better.

   -eric