KVM: Add kvm_x86_ops get_tdp_level()

The function get_tdp_level() provided the number of tdp level for EPT and
NPT rather than the NPT specific macro.

Signed-off-by: Sheng Yang <sheng.yang@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index bcfaf7e..20fb3c8 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1343,7 +1343,7 @@
 	spin_lock(&vcpu->kvm->mmu_lock);
 	kvm_mmu_free_some_pages(vcpu);
 	r = __direct_map(vcpu, gpa, error_code & PFERR_WRITE_MASK,
-			 largepage, gfn, pfn, TDP_ROOT_LEVEL);
+			 largepage, gfn, pfn, kvm_x86_ops->get_tdp_level());
 	spin_unlock(&vcpu->kvm->mmu_lock);
 
 	return r;
@@ -1450,7 +1450,7 @@
 	context->page_fault = tdp_page_fault;
 	context->free = nonpaging_free;
 	context->prefetch_page = nonpaging_prefetch_page;
-	context->shadow_root_level = TDP_ROOT_LEVEL;
+	context->shadow_root_level = kvm_x86_ops->get_tdp_level();
 	context->root_hpa = INVALID_PAGE;
 
 	if (!is_paging(vcpu)) {