KVM: Cache pdptrs

Instead of reloading the pdptrs on every entry and exit (vmcs writes on vmx,
guest memory access on svm) extract them on demand.

Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index 67785f6..4cb1dbf 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -131,7 +131,7 @@
 	pte = vcpu->arch.cr3;
 #if PTTYPE == 64
 	if (!is_long_mode(vcpu)) {
-		pte = vcpu->arch.pdptrs[(addr >> 30) & 3];
+		pte = kvm_pdptr_read(vcpu, (addr >> 30) & 3);
 		if (!is_present_pte(pte))
 			goto not_present;
 		--walker->level;