Xen I/O size improvements?

[Thor Lancelot Simon <tls%panix.com@localhost>]

With modern Xen and Linux kernels domains seem to be able to use MTU larger
than 1500 (up to 16K) on xennet.  I had a brief look at the code, but I do
not see specifically how this is supported.  Does anyone know?

Also, Xen now supports indirect descriptors to allow block I/O requests
much larger than the current 32K limit.  I had a look at the description
and the code but implementing it is probably beyond me.  Does anyone more
clever feel like having a shot at this?

	https://blog.xenproject.org/2013/08/07/indirect-descriptors-for-xen-pv-disks/

Thor