On Fri, Mar 16, 2018 at 04:21:14PM +0100, Jens Freimann wrote:

Add some helper functions to set/check descriptor flags
and toggle the used wrap counter.

Signed-off-by: Jens Freimann <redacted>

[...]

 
+static inline void
+toggle_wrap_counter(struct vhost_virtqueue *vq)
+{
+	vq->used_wrap_counter ^= 1;
+}
+
+static inline int
+desc_is_avail(struct vhost_virtqueue *vq, struct vring_desc_packed *desc)
+{
+	if (unlikely(!vq))
+		return -1;

Maybe it's better to let the caller make sure the vq
won't be NULL.

+
+	if (vq->used_wrap_counter == 1)
+		if ((desc->flags & DESC_AVAIL) && !(desc->flags & DESC_USED))
+			return 1;
+	if (vq->used_wrap_counter == 0)

Maybe it's better to use '} else {' here.

Thanks

+		if (!(desc->flags & DESC_AVAIL) && (desc->flags & DESC_USED))
+			return 1;
+	return 0;
+}