[dpdk-dev] [PATCH v6 06/10] vhost: add the APIs to operate inflight ring

[JinYu <jin.yu@intel.com>]

This patch introduces three APIs to operate the inflight
ring. Three APIs are set, set last and clear. It includes
split and packed ring.

Signed-off-by: Lin Li <lilin24@baidu.com>
Signed-off-by: Xun Ni <nixun@baidu.com>
Signed-off-by: Yu Zhang <zhangyu31@baidu.com>
Signed-off-by: Jin Yu <jin.yu@intel.com>
---
 lib/librte_vhost/rte_vhost.h | 116 ++++++++++++++++
 lib/librte_vhost/vhost.c     | 252 +++++++++++++++++++++++++++++++++++
 2 files changed, 368 insertions(+)

diff --git a/lib/librte_vhost/rte_vhost.h b/lib/librte_vhost/rte_vhost.h
index e090cdfee..d3b6eda21 100644
--- a/lib/librte_vhost/rte_vhost.h
+++ b/lib/librte_vhost/rte_vhost.h
@@ -693,6 +693,122 @@ int rte_vhost_get_mem_table(int vid, struct rte_vhost_memory **mem);
 int rte_vhost_get_vhost_vring(int vid, uint16_t vring_idx,
 			      struct rte_vhost_vring *vring);
 
+/**
+ * Set split inflight descriptor.
+ *
+ * This function save descriptors that has been comsumed in available
+ * ring
+ *
+ * @param vid
+ *  vhost device ID
+ * @param vring_idx
+ *  vring index
+ * @param idx
+ *  inflight entry index
+ * @return
+ *  0 on success, -1 on failure
+ */
+__rte_experimental
+int
+rte_vhost_set_inflight_desc_split(int vid, uint16_t vring_idx,
+	uint16_t idx);
+
+/**
+ * Set packed inflight descriptor and get corresponding inflight entry
+ *
+ * This function save descriptors that has been comsumed
+ *
+ * @param vid
+ *  vhost device ID
+ * @param vring_idx
+ *  vring index
+ * @param head
+ *  head of descriptors
+ * @param last
+ *  last of descriptors
+ * @param inflight_entry
+ *  corresponding inflight entry
+ * @return
+ *  0 on success, -1 on failure
+ */
+__rte_experimental
+int
+rte_vhost_set_inflight_desc_packed(int vid, uint16_t vring_idx,
+	uint16_t head, uint16_t last, uint16_t *inflight_entry);
+
+/**
+ * Save the head of list that the last batch of used descriptors.
+ *
+ * @param vid
+ *  vhost device ID
+ * @param vring_idx
+ *  vring index
+ * @param idx
+ *  descriptor entry index
+ * @return
+ *  0 on success, -1 on failure
+ */
+__rte_experimental
+int
+rte_vhost_set_last_inflight_io_split(int vid,
+	uint16_t vring_idx, uint16_t idx);
+
+/**
+ * Update the inflight free_head, used_idx and used_wrap_counter.
+ *
+ * This function will update status first before updating descriptors
+ * to used
+ *
+ * @param vid
+ *  vhost device ID
+ * @param vring_idx
+ *  vring index
+ * @param head
+ *  head of descriptors
+ * @return
+ *  0 on success, -1 on failure
+ */
+__rte_experimental
+int
+rte_vhost_set_last_inflight_io_packed(int vid,
+	uint16_t vring_idx, uint16_t head);
+
+/**
+ * Clear the split inflight status.
+ *
+ * @param vid
+ *  vhost device ID
+ * @param vring_idx
+ *  vring index
+ * @param last_used_idx
+ *  last used idx of used ring
+ * @param idx
+ *  inflight entry index
+ * @return
+ *  0 on success, -1 on failure
+ */
+__rte_experimental
+int
+rte_vhost_clr_inflight_desc_split(int vid, uint16_t vring_idx,
+	uint16_t last_used_idx, uint16_t idx);
+
+/**
+ * Clear the packed inflight status.
+ *
+ * @param vid
+ *  vhost device ID
+ * @param vring_idx
+ *  vring index
+ * @param head
+ *  inflight entry index
+ * @return
+ *  0 on success, -1 on failure
+ */
+__rte_experimental
+int
+rte_vhost_clr_inflight_desc_packed(int vid, uint16_t vring_idx,
+	uint16_t head);
+
 /**
  * Notify the guest that used descriptors have been added to the vring.  This
  * function acts as a memory barrier.
diff --git a/lib/librte_vhost/vhost.c b/lib/librte_vhost/vhost.c
index 660ac2a07..58940152f 100644
--- a/lib/librte_vhost/vhost.c
+++ b/lib/librte_vhost/vhost.c
@@ -783,6 +783,258 @@ rte_vhost_get_vhost_vring(int vid, uint16_t vring_idx,
 	return 0;
 }
 
+int
+rte_vhost_set_inflight_desc_split(int vid, uint16_t vring_idx,
+	uint16_t idx)
+{
+	struct virtio_net *dev;
+	struct vhost_virtqueue *vq;
+
+	dev = get_device(vid);
+	if (unlikely(!dev))
+		return -1;
+
+	if (unlikely(!(dev->protocol_features &
+		(1ULL << VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD))))
+		return 0;
+
+	if (unlikely(vq_is_packed(dev)))
+		return -1;
+
+	if (unlikely(vring_idx >= VHOST_MAX_VRING))
+		return -1;
+
+	vq = dev->virtqueue[vring_idx];
+	if (unlikely(!vq))
+		return -1;
+
+	if (unlikely(!vq->inflight_split))
+		return -1;
+
+	vq->inflight_split->desc[idx].counter = vq->global_counter++;
+	vq->inflight_split->desc[idx].inflight = 1;
+	return 0;
+}
+
+int
+rte_vhost_set_inflight_desc_packed(int vid, uint16_t vring_idx,
+	uint16_t head, uint16_t last, uint16_t *inflight_entry)
+{
+	struct virtio_net *dev;
+	struct vhost_virtqueue *vq;
+	struct inflight_info_packed *inflight_info;
+	struct vring_packed_desc *desc;
+	uint16_t old_free_head, free_head;
+
+	dev = get_device(vid);
+	if (unlikely(!dev))
+		return -1;
+
+	if (unlikely(!(dev->protocol_features &
+		(1ULL << VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD))))
+		return 0;
+
+	if (unlikely(!vq_is_packed(dev)))
+		return -1;
+
+	if (unlikely(vring_idx >= VHOST_MAX_VRING))
+		return -1;
+
+	vq = dev->virtqueue[vring_idx];
+	if (unlikely(!vq))
+		return -1;
+
+	inflight_info = vq->inflight_packed;
+	if (unlikely(!inflight_info))
+		return -1;
+
+	desc = vq->desc_packed;
+	old_free_head = inflight_info->old_free_head;
+	free_head = old_free_head;
+
+	/* init header descriptor */
+	inflight_info->desc[old_free_head].num = 0;
+	inflight_info->desc[old_free_head].counter = vq->global_counter++;
+	inflight_info->desc[old_free_head].inflight = 1;
+
+	/* save desc entry in flight entry */
+	while (head != ((last + 1) % vq->size)) {
+		inflight_info->desc[old_free_head].num++;
+		inflight_info->desc[free_head].addr = desc[head].addr;
+		inflight_info->desc[free_head].len = desc[head].len;
+		inflight_info->desc[free_head].flags = desc[head].flags;
+		inflight_info->desc[free_head].id = desc[head].id;
+
+		inflight_info->desc[old_free_head].last = free_head;
+		free_head = inflight_info->desc[free_head].next;
+		inflight_info->free_head = free_head;
+		head = (head + 1) % vq->size;
+	}
+
+	inflight_info->old_free_head = free_head;
+	*inflight_entry = old_free_head;
+
+	return 0;
+}
+
+int
+rte_vhost_clr_inflight_desc_split(int vid, uint16_t vring_idx,
+	uint16_t last_used_idx, uint16_t idx)
+{
+	struct virtio_net *dev;
+	struct vhost_virtqueue *vq;
+
+	dev = get_device(vid);
+	if (unlikely(!dev))
+		return -1;
+
+	if (unlikely(!(dev->protocol_features &
+		(1ULL << VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD))))
+		return 0;
+
+	if (unlikely(vq_is_packed(dev)))
+		return -1;
+
+	if (unlikely(vring_idx >= VHOST_MAX_VRING))
+		return -1;
+
+	vq = dev->virtqueue[vring_idx];
+	if (unlikely(!vq))
+		return -1;
+
+	if (unlikely(!vq->inflight_split))
+		return -1;
+
+	rte_compiler_barrier();
+
+	vq->inflight_split->desc[idx].inflight = 0;
+
+	rte_compiler_barrier();
+
+	vq->inflight_split->used_idx = last_used_idx;
+	return 0;
+}
+
+int
+rte_vhost_clr_inflight_desc_packed(int vid, uint16_t vring_idx,
+	uint16_t head)
+{
+	struct virtio_net *dev;
+	struct vhost_virtqueue *vq;
+	struct inflight_info_packed *inflight_info;
+
+	dev = get_device(vid);
+	if (unlikely(!dev))
+		return -1;
+
+	if (unlikely(!(dev->protocol_features &
+		(1ULL << VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD))))
+		return 0;
+
+	if (unlikely(!vq_is_packed(dev)))
+		return -1;
+
+	if (unlikely(vring_idx >= VHOST_MAX_VRING))
+		return -1;
+
+	vq = dev->virtqueue[vring_idx];
+	if (unlikely(!vq))
+		return -1;
+
+	inflight_info = vq->inflight_packed;
+	if (unlikely(!inflight_info))
+		return -1;
+
+	rte_compiler_barrier();
+
+	inflight_info->desc[head].inflight = 0;
+
+	rte_compiler_barrier();
+
+	inflight_info->old_free_head = inflight_info->free_head;
+	inflight_info->old_used_idx = inflight_info->used_idx;
+	inflight_info->old_used_wrap_counter = inflight_info->used_wrap_counter;
+
+	return 0;
+}
+
+int
+rte_vhost_set_last_inflight_io_split(int vid, uint16_t vring_idx,
+	uint16_t idx)
+{
+	struct virtio_net *dev;
+	struct vhost_virtqueue *vq;
+
+	dev = get_device(vid);
+	if (unlikely(!dev))
+		return -1;
+
+	if (unlikely(!(dev->protocol_features &
+		(1ULL << VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD))))
+		return 0;
+
+	if (unlikely(vq_is_packed(dev)))
+		return -1;
+
+	if (unlikely(vring_idx >= VHOST_MAX_VRING))
+		return -1;
+
+	vq = dev->virtqueue[vring_idx];
+	if (unlikely(!vq))
+		return -1;
+
+	if (unlikely(!vq->inflight_split))
+		return -1;
+
+	vq->inflight_split->last_inflight_io = idx;
+	return 0;
+}
+
+int
+rte_vhost_set_last_inflight_io_packed(int vid, uint16_t vring_idx,
+	uint16_t head)
+{
+	struct virtio_net *dev;
+	struct vhost_virtqueue *vq;
+	struct inflight_info_packed *inflight_info;
+	uint16_t last;
+
+	dev = get_device(vid);
+	if (unlikely(!dev))
+		return -1;
+
+	if (unlikely(!(dev->protocol_features &
+		(1ULL << VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD))))
+		return 0;
+
+	if (unlikely(!vq_is_packed(dev)))
+		return -1;
+
+	if (unlikely(vring_idx >= VHOST_MAX_VRING))
+		return -1;
+
+	vq = dev->virtqueue[vring_idx];
+	if (unlikely(!vq))
+		return -1;
+
+	inflight_info = vq->inflight_packed;
+	if (unlikely(!inflight_info))
+		return -1;
+
+	last = inflight_info->desc[head].last;
+
+	inflight_info->desc[last].next = inflight_info->free_head;
+	inflight_info->free_head = head;
+	inflight_info->used_idx += inflight_info->desc[head].num;
+	if (inflight_info->used_idx >= inflight_info->desc_num) {
+		inflight_info->used_idx -= inflight_info->desc_num;
+		inflight_info->used_wrap_counter =
+			!inflight_info->used_wrap_counter;
+	}
+
+	return 0;
+}
+
 int
 rte_vhost_vring_call(int vid, uint16_t vring_idx)
 {
-- 
2.17.2