KVM: X86: Introduce kvm_get_msr_feature()

KVM: X86: Introduce kvm_get_msr_feature()

Introduce kvm_get_msr_feature() to handle the msrs which are supported
by different vendors and sharing the same emulation logic.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Liran Alon <liran.alon@oracle.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
CVE-2018-3620
CVE-2018-3646

(cherry picked from commit 66421c1ec340096b291af763ed5721314cdd9c5c)
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>