KVM: x86: introduce is_pae_paging

Checking for 32-bit PAE is quite common around code that fiddles with
the PDPTRs.  Add a function to compress all checks into a single
invocation.

Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/x86.h

@@ -139,6 +139,11 @@ static inline int is_paging(struct kvm_vcpu *vcpu)
 	return likely(kvm_read_cr0_bits(vcpu, X86_CR0_PG));
 }
 
+static inline bool is_pae_paging(struct kvm_vcpu *vcpu)
+{
+	return !is_long_mode(vcpu) && is_pae(vcpu) && is_paging(vcpu);
+}
+
 static inline u32 bit(int bitno)
 {
 	return 1 << (bitno & 31);