KVM: x86/mmu: WARN if TDP MMU SP disallows hugepage after being zapped

Extend the accounting sanity check in kvm_recover_nx_huge_pages() to the
TDP MMU, i.e. verify that zapping a shadow page unaccounts the disallowed
NX huge page regardless of the MMU type.  Recovery runs while holding
mmu_lock for write and so it should be impossible to get false positives
on the WARN.
Suggested-by: Yan Zhao <yan.y.zhao@intel.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20221019165618.927057-9-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/mmu/mmu.c

@@ -6875,12 +6875,11 @@ static void kvm_recover_nx_huge_pages(struct kvm *kvm)
 				      struct kvm_mmu_page,
 				      possible_nx_huge_page_link);
 		WARN_ON_ONCE(!sp->nx_huge_page_disallowed);
-		if (is_tdp_mmu_page(sp)) {
+		if (is_tdp_mmu_page(sp))
 			flush |= kvm_tdp_mmu_zap_sp(kvm, sp);
-		} else {
+		else
 			kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list);
-			WARN_ON_ONCE(sp->nx_huge_page_disallowed);
-		}
+		WARN_ON_ONCE(sp->nx_huge_page_disallowed);
 
 		if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) {
 			kvm_mmu_remote_flush_or_zap(kvm, &invalid_list, flush);