K 10
svn:author
V 5
sephe
K 8
svn:date
V 27
2016-05-30T08:25:09.032705Z
K 7
svn:log
V 463
hyperv/et: Fix STIMER0 operations.

- Make sure that STIMER0 is disabled before writting to it, since
  writing to an enabled STIMER will result in undefined behaviour.
- It is unnecessary to reconfigure STIMER0 upon each et_start().
- Make sure that MSR_HV_REF_TIME_COUNT will not return 0, since
  writing 0 to STIMER_COUNT will disable the target STIMER.

MFC after:	1 week
Sponsored by:	Microsoft OSTC
Differential Revision:	https://reviews.freebsd.org/D6573

END