CA-141856: Preserve update barrier ordering

Signed-off-by: Si Beaumont <simon.beaumont@citrix.com>
Merge commit '33665b62dce390a4598544edaac5d11c8adb1bce'
Merge commit '6272d2539f0a6934dbdb23ff06bb41dacb5ba26f'
Merge remote-tracking branch 'creedence/master' into xs64bit-ring3

Merging creedence into staging branch due to cherry picking of CA-141856
fix.