KVM: arm64: Check the pgt instead of the pgd when modifying page-table

In preparation for removing the 'pgd' field of 'struct kvm_s2_mmu',
update the few remaining users to check the 'pgt' field instead.
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Quentin Perret <qperret@google.com>
Link: https://lore.kernel.org/r/20200911132529.19844-19-will@kernel.org

arch/arm64/kvm/mmu.c

@@ -1829,7 +1829,7 @@ static int kvm_unmap_hva_handler(struct kvm *kvm, gpa_t gpa, u64 size, void *dat
 int kvm_unmap_hva_range(struct kvm *kvm,
 			unsigned long start, unsigned long end, unsigned flags)
 {
-	if (!kvm->arch.mmu.pgd)
+	if (!kvm->arch.mmu.pgt)
 		return 0;
 
 	trace_kvm_unmap_hva_range(start, end);
@@ -1892,7 +1892,7 @@ static int kvm_test_age_hva_handler(struct kvm *kvm, gpa_t gpa, u64 size, void *
 
 int kvm_age_hva(struct kvm *kvm, unsigned long start, unsigned long end)
 {
-	if (!kvm->arch.mmu.pgd)
+	if (!kvm->arch.mmu.pgt)
 		return 0;
 	trace_kvm_age_hva(start, end);
 	return handle_hva_to_gpa(kvm, start, end, kvm_age_hva_handler, NULL);
@@ -1900,7 +1900,7 @@ int kvm_age_hva(struct kvm *kvm, unsigned long start, unsigned long end)
 
 int kvm_test_age_hva(struct kvm *kvm, unsigned long hva)
 {
-	if (!kvm->arch.mmu.pgd)
+	if (!kvm->arch.mmu.pgt)
 		return 0;
 	trace_kvm_test_age_hva(hva);
 	return handle_hva_to_gpa(kvm, hva, hva + PAGE_SIZE,