diff --git a/arch/powerpc/kvm/book3s_64_vio.c b/arch/powerpc/kvm/book3s_64_vio.c
index 50555ad1db93..1a529df0ab44 100644
--- a/arch/powerpc/kvm/book3s_64_vio.c
+++ b/arch/powerpc/kvm/book3s_64_vio.c
@@ -73,6 +73,7 @@ extern void kvm_spapr_tce_release_iommu_group(struct kvm *kvm,
 	struct kvmppc_spapr_tce_iommu_table *stit, *tmp;
 	struct iommu_table_group *table_group = NULL;
 
+	rcu_read_lock();
 	list_for_each_entry_rcu(stt, &kvm->arch.spapr_tce_tables, list) {
 
 		table_group = iommu_group_get_iommudata(grp);
@@ -87,7 +88,9 @@ extern void kvm_spapr_tce_release_iommu_group(struct kvm *kvm,
 				kref_put(&stit->kref, kvm_spapr_tce_liobn_put);
 			}
 		}
+		cond_resched_rcu();
 	}
+	rcu_read_unlock();
 }
 
 extern long kvm_spapr_tce_attach_iommu_group(struct kvm *kvm, int tablefd,
@@ -105,12 +108,14 @@ extern long kvm_spapr_tce_attach_iommu_group(struct kvm *kvm, int tablefd,
 	if (!f.file)
 		return -EBADF;
 
+	rcu_read_lock();
 	list_for_each_entry_rcu(stt, &kvm->arch.spapr_tce_tables, list) {
 		if (stt == f.file->private_data) {
 			found = true;
 			break;
 		}
 	}
+	rcu_read_unlock();
 
 	fdput(f);
 
@@ -143,6 +148,7 @@ extern long kvm_spapr_tce_attach_iommu_group(struct kvm *kvm, int tablefd,
 	if (!tbl)
 		return -EINVAL;
 
+	rcu_read_lock();
 	list_for_each_entry_rcu(stit, &stt->iommu_tables, next) {
 		if (tbl != stit->tbl)
 			continue;
@@ -150,14 +156,17 @@ extern long kvm_spapr_tce_attach_iommu_group(struct kvm *kvm, int tablefd,
 		if (!kref_get_unless_zero(&stit->kref)) {
 			/* stit is being destroyed */
 			iommu_tce_table_put(tbl);
+			rcu_read_unlock();
 			return -ENOTTY;
 		}
 		/*
 		 * The table is already known to this KVM, we just increased
 		 * its KVM reference counter and can return.
 		 */
+		rcu_read_unlock();
 		return 0;
 	}
+	rcu_read_unlock();
 
 	stit = kzalloc(sizeof(*stit), GFP_KERNEL);
 	if (!stit) {
@@ -365,18 +374,19 @@ static long kvmppc_tce_validate(struct kvmppc_spapr_tce_table *stt,
 	if (kvmppc_tce_to_ua(stt->kvm, tce, &ua))
 		return H_TOO_HARD;
 
+	rcu_read_lock();
 	list_for_each_entry_rcu(stit, &stt->iommu_tables, next) {
 		unsigned long hpa = 0;
 		struct mm_iommu_table_group_mem_t *mem;
 		long shift = stit->tbl->it_page_shift;
 
 		mem = mm_iommu_lookup(stt->kvm->mm, ua, 1ULL << shift);
-		if (!mem)
-			return H_TOO_HARD;
-
-		if (mm_iommu_ua_to_hpa(mem, ua, shift, &hpa))
+		if (!mem || mm_iommu_ua_to_hpa(mem, ua, shift, &hpa)) {
+			rcu_read_unlock();
 			return H_TOO_HARD;
+		}
 	}
+	rcu_read_unlock();
 
 	return H_SUCCESS;
 }