All,
     Attached is a patch to make batched PTE updates smarter.  Basically, if you
run a kernel with batched PTE capability on a hypervisor that doesn't support
it, you get lots of:

(XEN) mm.c:2453:d2 Invalid page update command 2
(XEN) printk: 333 messages suppressed.
(XEN) mm.c:2453:d2 Invalid page update command 2

on the hypervisor console.

It doesn't seem to be a security problem, since it is rate-limited, but it is an
annoyance.  The patch just looks at the return code from the first such
hypercall, and if we fail with ENOSYS, we just mark it as
"hypervisor_no_batch_update" and never try again.  Patch originally from Rik van
Riel.

Signed-off-by: Chris Lalancette <clalance@redhat.com>