This fixes a Spectre-v1/L1TF vulnerability in set_msr_mce() and
get_msr_mce().
Both functions contain index computations based on the
(attacker-controlled) MSR number.

Fixes: 890ca9ae ("KVM: Add MCE support")
Signed-off-by: NNick Finco <nifi@google.com>
Signed-off-by: NMarios Pomonis <pomonis@google.com>
Reviewed-by: NAndrew Honig <ahonig@google.com>
Cc: stable@vger.kernel.org
Reviewed-by: NJim Mattson <jmattson@google.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>