@ https://bugzilla.redhat.com/show_bug.cgi?id=582570

just MARK

The performance counters are not available to profile in virtualized
environments. You might be able to use the timer mode within the
DomU.

If just measuring things within a domU, as root you could do the following to
use the timer mode:

opcontrol --deinit
rm -f /root/.oprofile/daemonrc
modprobe oprofile timer=1
opcontrol --reset
opcontrol --vmlinux=/usr/lib/debug/lib/modules/`uname -r`/vmlinux \
  --separate=library
opcontrol --start