diff --git a/sys/dev/virtio/random/virtio_random.c b/sys/dev/virtio/random/virtio_random.c
--- a/sys/dev/virtio/random/virtio_random.c
+++ b/sys/dev/virtio/random/virtio_random.c
@@ -56,7 +56,11 @@
 	struct virtqueue	*vtrnd_vq;
 	eventhandler_tag	 eh;
 	bool			 inactive;
+	struct sglist_seg	 vtrnd_segs[1];
+	struct sglist		 vtrnd_sg;
+	uint32_t		 vtrnd_value[HARVESTSIZE] __aligned(sizeof(uint32_t) * HARVESTSIZE);
 };
+_Static_assert(sizeof(((struct vtrnd_softc *)NULL)->vtrnd_value) < PAGE_SIZE, "sglist assumption");
 
 static int	vtrnd_modevent(module_t, int, void *);
 
@@ -69,6 +73,7 @@
 static int	vtrnd_setup_features(struct vtrnd_softc *);
 static int	vtrnd_alloc_virtqueue(struct vtrnd_softc *);
 static int	vtrnd_harvest(struct vtrnd_softc *, void *, size_t *);
+static void	vtrnd_enqueue(struct vtrnd_softc *sc);
 static unsigned	vtrnd_read(void *, unsigned);
 
 #define VTRND_FEATURES	0
@@ -176,6 +181,8 @@
 	sc->inactive = false;
 	random_source_register(&random_vtrnd);
 
+	vtrnd_enqueue(sc);
+
 fail:
 	if (error)
 		vtrnd_detach(dev);
@@ -187,6 +194,7 @@
 vtrnd_detach(device_t dev)
 {
 	struct vtrnd_softc *sc;
+	uint32_t rdlen;
 
 	sc = device_get_softc(dev);
 	KASSERT(
@@ -199,6 +207,10 @@
 		sc->eh = NULL;
 	}
 	random_source_deregister(&random_vtrnd);
+
+	/* clear the queue */
+	virtqueue_poll(sc->vtrnd_vq, &rdlen);
+
 	atomic_store_explicit(&g_vtrnd_softc, NULL, memory_order_release);
 	return (0);
 }
@@ -253,49 +265,52 @@
 	return (virtio_alloc_virtqueues(dev, 0, 1, &vq_info));
 }
 
-static int
-vtrnd_harvest(struct vtrnd_softc *sc, void *buf, size_t *sz)
+static void
+vtrnd_enqueue(struct vtrnd_softc *sc)
 {
-	struct sglist_seg segs[1];
-	struct sglist sg;
 	struct virtqueue *vq;
-	uint32_t value[HARVESTSIZE] __aligned(sizeof(uint32_t) * HARVESTSIZE);
-	uint32_t rdlen;
+	struct sglist *sg;
 	int error;
 
-	_Static_assert(sizeof(value) < PAGE_SIZE, "sglist assumption");
-
-	if (sc->inactive)
-		return (EDEADLK);
+	sg = &sc->vtrnd_sg;
+	vq = sc->vtrnd_vq;
 
-	sglist_init(&sg, 1, segs);
-	error = sglist_append(&sg, value, *sz);
+	sglist_init(sg, 1, sc->vtrnd_segs);
+	error = sglist_append(sg, sc->vtrnd_value, sizeof(sc->vtrnd_value));
 	if (error != 0)
 		panic("%s: sglist_append error=%d", __func__, error);
 
-	vq = sc->vtrnd_vq;
 	KASSERT(virtqueue_empty(vq), ("%s: non-empty queue", __func__));
 
-	error = virtqueue_enqueue(vq, buf, &sg, 0, 1);
-	if (error != 0)
-		return (error);
+	error = virtqueue_enqueue(vq, sc, sg, 0, 1);
+	KASSERT(error == 0, ("%s: virtqueue_enqueue returned error: %d", __func__, error));
 
-	/*
-	 * Poll for the response, but the command is likely already
-	 * done when we return from the notify.
-	 */
 	virtqueue_notify(vq);
-	virtqueue_poll(vq, &rdlen);
+}
 
-	if (rdlen > *sz)
-		panic("%s: random device wrote %zu bytes beyond end of provided"
-		    " buffer %p:%zu", __func__, (size_t)rdlen - *sz,
-		    (void *)value, *sz);
-	else if (rdlen == 0)
+int
+vtrnd_harvest(struct vtrnd_softc *sc, void *buf, size_t *sz)
+{
+	struct virtqueue *vq;
+	void *cookie;
+	uint32_t rdlen;
+
+	if (sc->inactive)
+		return (EDEADLK);
+
+	vq = sc->vtrnd_vq;
+
+	cookie = virtqueue_dequeue(vq, &rdlen);
+
+	if (cookie == NULL)
 		return (EAGAIN);
+
 	*sz = MIN(rdlen, *sz);
-	memcpy(buf, value, *sz);
-	explicit_bzero(value, *sz);
+	memcpy(buf, sc->vtrnd_value, *sz);
+	explicit_bzero(sc->vtrnd_value, *sz);
+
+	vtrnd_enqueue(sc);
+
 	return (0);
 }