Adds code to keep track of the number of hypervisor calls made and
the amount of time spent in hypervisor calls. Wall time spent in
each call is always calculated, and if available CPU cycles spent
are also calculated. A directory named hcall_inst is added at the
root of the debugfs filesystem. Within the hcall_inst directory
are files that contain CPU specific call statistics.

This option will add a small amount of overhead to all hypervisor
calls.

source code:

arch/powerpc/platforms/pseries/hvCall_inst.c