This insn differs from WRMSR solely in the lack of serialization. Hence
the code used there can simply be used here as well, plus a feature
check of course. As there's no other infrastructure needed beyond
permitting the insn for PV privileged-op emulation (in particular no
separate new VMEXIT) we can expose the insn to guests right away.
Don't expose the feature to PV guests, as the involved #UD is
serializing anyway.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>