spte_to_child_pt
child_pt = spte_to_child_pt(iter->old_spte, iter->level);
tdp_ptep_t spte_to_child_pt(u64 pte, int level);
handle_removed_pt(kvm, spte_to_child_pt(old_spte, level), shared);
if ((tdp_ptep_t)sp->spt != spte_to_child_pt(iter.old_spte, iter.level))
WARN_ON_ONCE((tdp_ptep_t)sp->spt == spte_to_child_pt(iter.old_spte, iter.level));