KVM: Add SMAP support when setting CR4

This patch adds SMAP handling logic when setting CR4 for guests

Thanks a lot to Paolo Bonzini for his suggestion to use the branchless
way to detect SMAP violation.

Signed-off-by: Feng Wu <feng.wu@intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

diff --cc arch/x86/kvm/cpuid.h
Simple merge

diff --cc arch/x86/kvm/mmu.c
Simple merge

diff --cc arch/x86/kvm/mmu.h
Simple merge

diff --cc arch/x86/kvm/paging_tmpl.h
Simple merge

diff --cc arch/x86/kvm/x86.c
Simple merge