KVM: x86/mmu: Update page stats in __rmap_add()

Update the page stats in __rmap_add() rather than at the call site. This
will avoid having to manually update page stats when splitting huge
pages in a subsequent commit.

No functional change intended.
Reviewed-by: NBen Gardon <bgardon@google.com>
Reviewed-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NDavid Matlack <dmatlack@google.com>
Message-Id: <20220516232138.1783324-17-dmatlack@google.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/mmu/mmu.c

@@ -1562,6 +1562,8 @@ static void __rmap_add(struct kvm *kvm,
 
 	sp = sptep_to_sp(spte);
 	kvm_mmu_page_set_gfn(sp, spte - sp->spt, gfn);
+	kvm_update_page_stats(kvm, sp->role.level, 1);
+
 	rmap_head = gfn_to_rmap(gfn, sp->role.level, slot);
 	rmap_count = pte_list_add(cache, spte, rmap_head);
 
@@ -2783,7 +2785,6 @@ static int mmu_set_spte(struct kvm_vcpu *vcpu, struct kvm_memory_slot *slot,
 
 	if (!was_rmapped) {
 		WARN_ON_ONCE(ret == RET_PF_SPURIOUS);
-		kvm_update_page_stats(vcpu->kvm, level, 1);
 		rmap_add(vcpu, slot, sptep, gfn);
 	}