Add some helper functions to set/check descriptor flags
and toggle the used wrap counter.
Signed-off-by: Jens Freimann <jfreim...@redhat.com>
---
lib/librte_vhost/virtio-1.1.h | 43 +++++++++++++++++++++++++++++++++++++++++++
1 file changed, 43 insertions(+)
diff --git a/lib/librte_vhost/virtio-1.1.h b/lib/librte_vhost/virtio-1.1.h
index b37d621..7b37d26 100644
--- a/lib/librte_vhost/virtio-1.1.h
+++ b/lib/librte_vhost/virtio-1.1.h
@@ -17,4 +17,47 @@ struct vring_desc_packed {
uint16_t flags;
};
+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;
+
+ if (vq->used_wrap_counter == 1)
+ if ((desc->flags & DESC_AVAIL) && !(desc->flags & DESC_USED))
+ return 1;
+ if (vq->used_wrap_counter == 0)
+ if (!(desc->flags & DESC_AVAIL) && (desc->flags & DESC_USED))
+ return 1;
+ return 0;
+}
+
+static inline void
+_set_desc_used(struct vring_desc_packed *desc, int wrap_counter)
+{
+ uint16_t flags = desc->flags;
+
+ if (wrap_counter == 1) {
+ flags |= DESC_USED;
+ flags |= DESC_AVAIL;
+ } else {
+ flags &= ~DESC_USED;
+ flags &= ~DESC_AVAIL;
+ }
+
+ desc->flags = flags;
+}
+
+static inline void
+set_desc_used(struct vhost_virtqueue *vq, struct vring_desc_packed *desc)
+{
+ _set_desc_used(desc, vq->used_wrap_counter);
+}
+
#endif /* __VIRTIO_PACKED_H */
--
1.8.3.1
