diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
index 9afdc4c4a5dc15f9bf4a1972894e2b046f5489d6..a395b6c0aae2a92e40b88dc37faa2829df9f95f0 100644
--- a/arch/arm/xen/enlighten.c
+++ b/arch/arm/xen/enlighten.c
@@ -484,7 +484,8 @@ static int __init xen_guest_init(void)
 	 * for secondary CPUs as they are brought up.
 	 * For uniformity we use VCPUOP_register_vcpu_info even on cpu0.
 	 */
-	xen_vcpu_info = alloc_percpu(struct vcpu_info);
+	xen_vcpu_info = __alloc_percpu(sizeof(struct vcpu_info),
+				       1 << fls(sizeof(struct vcpu_info) - 1));
 	if (xen_vcpu_info == NULL)
 		return -ENOMEM;
 
diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c
index 1ce7f3c7a950931e0655df5f8587aee3adacd6be..0eb337a8ec0fa2a1df0bd392b9ec0381a8658758 100644
--- a/drivers/xen/privcmd.c
+++ b/drivers/xen/privcmd.c
@@ -1115,7 +1115,7 @@ struct privcmd_kernel_ioreq {
 	spinlock_t lock; /* Protects ioeventfds list */
 	struct list_head ioeventfds;
 	struct list_head list;
-	struct ioreq_port ports[0];
+	struct ioreq_port ports[] __counted_by(vcpus);
 };
 
 static irqreturn_t ioeventfd_interrupt(int irq, void *dev_id)
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index 946bd56f0ac53e23a4f5215fd4412901b9be296f..0e6c6c25d154f5e2e439aa261397298fb0ac8118 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -405,4 +405,5 @@ const struct dma_map_ops xen_swiotlb_dma_ops = {
 	.get_sgtable = dma_common_get_sgtable,
 	.alloc_pages = dma_common_alloc_pages,
 	.free_pages = dma_common_free_pages,
+	.max_mapping_size = swiotlb_max_mapping_size,
 };