--- qemu/linux-headers/linux/virtio_ring.h	2018/04/24 18:56:56	1.1.1.1
+++ qemu/linux-headers/linux/virtio_ring.h	2018/04/24 19:35:28	1.1.1.2
@@ -135,13 +135,13 @@ static __inline__ void vring_init(struct
 	vr->num = num;
 	vr->desc = p;
 	vr->avail = p + num*sizeof(struct vring_desc);
-	vr->used = (void *)(((unsigned long)&vr->avail->ring[num] + align-1)
-			    & ~(align - 1));
+	vr->used = (void *)(((unsigned long)&vr->avail->ring[num] + sizeof(__u16)
+		+ align-1) & ~(align - 1));
 }
 
 static __inline__ unsigned vring_size(unsigned int num, unsigned long align)
 {
-	return ((sizeof(struct vring_desc) * num + sizeof(__u16) * (2 + num)
+	return ((sizeof(struct vring_desc) * num + sizeof(__u16) * (3 + num)
 		 + align - 1) & ~(align - 1))
 		+ sizeof(__u16) * 3 + sizeof(struct vring_used_elem) * num;
 }