diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 9b1d62d03370..72c6d647bec9 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -3561,7 +3561,8 @@ static void intel_unmap(struct device *dev, dma_addr_t dev_addr, size_t size)
 
 	freelist = domain_unmap(domain, start_pfn, last_pfn);
 
-	if (intel_iommu_strict || (pdev && pdev->untrusted)) {
+	if (intel_iommu_strict || (pdev && pdev->untrusted) ||
+			!has_iova_flush_queue(&domain->iovad)) {
 		iommu_flush_iotlb_psi(iommu, domain, start_pfn,
 				      nrpages, !freelist, 0);
 		/* free iova */
diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c
index d499b2621239..8413ae54904a 100644
--- a/drivers/iommu/iova.c
+++ b/drivers/iommu/iova.c
@@ -54,9 +54,14 @@ init_iova_domain(struct iova_domain *iovad, unsigned long granule,
 }
 EXPORT_SYMBOL_GPL(init_iova_domain);
 
+bool has_iova_flush_queue(struct iova_domain *iovad)
+{
+	return !!iovad->fq;
+}
+
 static void free_iova_flush_queue(struct iova_domain *iovad)
 {
-	if (!iovad->fq)
+	if (!has_iova_flush_queue(iovad))
 		return;
 
 	if (timer_pending(&iovad->fq_timer))
@@ -74,13 +79,14 @@ static void free_iova_flush_queue(struct iova_domain *iovad)
 int init_iova_flush_queue(struct iova_domain *iovad,
 			  iova_flush_cb flush_cb, iova_entry_dtor entry_dtor)
 {
+	struct iova_fq __percpu *queue;
 	int cpu;
 
 	atomic64_set(&iovad->fq_flush_start_cnt,  0);
 	atomic64_set(&iovad->fq_flush_finish_cnt, 0);
 
-	iovad->fq = alloc_percpu(struct iova_fq);
-	if (!iovad->fq)
+	queue = alloc_percpu(struct iova_fq);
+	if (!queue)
 		return -ENOMEM;
 
 	iovad->flush_cb   = flush_cb;
@@ -89,13 +95,17 @@ int init_iova_flush_queue(struct iova_domain *iovad,
 	for_each_possible_cpu(cpu) {
 		struct iova_fq *fq;
 
-		fq = per_cpu_ptr(iovad->fq, cpu);
+		fq = per_cpu_ptr(queue, cpu);
 		fq->head = 0;
 		fq->tail = 0;
 
 		spin_lock_init(&fq->lock);
 	}
 
+	smp_wmb();
+
+	iovad->fq = queue;
+
 	timer_setup(&iovad->fq_timer, fq_flush_timeout, 0);
 	atomic_set(&iovad->fq_timer_on, 0);
 
diff --git a/include/linux/iova.h b/include/linux/iova.h
index 781b96ac706f..cd0f1de901a8 100644
--- a/include/linux/iova.h
+++ b/include/linux/iova.h
@@ -155,6 +155,7 @@ struct iova *reserve_iova(struct iova_domain *iovad, unsigned long pfn_lo,
 void copy_reserved_iova(struct iova_domain *from, struct iova_domain *to);
 void init_iova_domain(struct iova_domain *iovad, unsigned long granule,
 	unsigned long start_pfn);
+bool has_iova_flush_queue(struct iova_domain *iovad);
 int init_iova_flush_queue(struct iova_domain *iovad,
 			  iova_flush_cb flush_cb, iova_entry_dtor entry_dtor);
 struct iova *find_iova(struct iova_domain *iovad, unsigned long pfn);
@@ -235,6 +236,11 @@ static inline void init_iova_domain(struct iova_domain *iovad,
 {
 }
 
+bool has_iova_flush_queue(struct iova_domain *iovad)
+{
+	return false;
+}
+
 static inline int init_iova_flush_queue(struct iova_domain *iovad,
 					iova_flush_cb flush_cb,
 					iova_entry_dtor entry_dtor)