[PATCH 11/14] vhost: add helpers for packed virtqueues
From: Jens Freimann <hidden>
Date: 2018-01-29 14:13:10
Subsystem:
library code, the rest · Maintainers:
Andrew Morton, Linus Torvalds
Add some helper functions to set/check descriptor flags and toggle the used wrap counter. Signed-off-by: Jens Freimann <redacted> --- 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 5ca0bc33f..84039797e 100644
--- a/lib/librte_vhost/virtio-1.1.h
+++ b/lib/librte_vhost/virtio-1.1.h@@ -17,4 +17,47 @@ struct vring_desc_1_1 { 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_1_1 *desc) +{ + if (!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_1_1 *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_1_1 *desc) +{ + _set_desc_used(desc, vq->used_wrap_counter); +} + #endif /* __VIRTIO_1_1_H */
--
2.14.3