KVM: Use rsvd_bits_mask in load_pdptrs()

Also remove bit 5-6 from rsvd_bits_mask per latest SDM.

Signed-off-by: Eddie Dong <Eddie.Dong@intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
index eaab214..3494a2f 100644
--- a/arch/x86/kvm/mmu.h
+++ b/arch/x86/kvm/mmu.h
@@ -75,4 +75,9 @@
 	return vcpu->arch.cr0 & X86_CR0_PG;
 }
 
+static inline int is_present_pte(unsigned long pte)
+{
+	return pte & PT_PRESENT_MASK;
+}
+
 #endif