Impact: re-enable CPUID unmasking on affected processors
As far as I am capable of discerning from the documentation,
MSR_IA32_MISC_ENABLE should be available for all family 0xf CPUs, as
well as family 6 for model >= 0xd (newer Pentium M).
The documentation on this isn't ideal, so we need to be on the lookout
for errors, still.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
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