In async data path, when vring state changes or device is destroyed,
it is necessary to know the number of inflight packets in DMA engine.
This patch provides a thread unsafe API to return the number of
inflight packets for a vhost queue without using any lock.
Signed-off-by: Xuan Ding <xuan.d...@intel.com>
---
doc/guides/prog_guide/vhost_lib.rst | 5 +++++
doc/guides/rel_notes/release_21_11.rst | 5 +++++
lib/vhost/rte_vhost_async.h | 14 ++++++++++++++
lib/vhost/version.map | 3 +++
lib/vhost/vhost.c | 26 ++++++++++++++++++++++++++
5 files changed, 53 insertions(+)
diff --git a/doc/guides/prog_guide/vhost_lib.rst
b/doc/guides/prog_guide/vhost_lib.rst
index 8874033165..0c4fb9ea91 100644
--- a/doc/guides/prog_guide/vhost_lib.rst
+++ b/doc/guides/prog_guide/vhost_lib.rst
@@ -305,6 +305,11 @@ The following is an overview of some key Vhost API
functions:
This function returns the amount of in-flight packets for the vhost
queue using async acceleration.
+* ``rte_vhost_async_get_inflight_thread_unsafe(vid, queue_id)``
+
+ Get the number of inflight packets for a vhost queue without
+ performing any locking.
+
* ``rte_vhost_clear_queue_thread_unsafe(vid, queue_id, **pkts, count)``
Clear inflight packets which are submitted to DMA engine in vhost async data
diff --git a/doc/guides/rel_notes/release_21_11.rst
b/doc/guides/rel_notes/release_21_11.rst
index 675b573834..c9814c68df 100644
--- a/doc/guides/rel_notes/release_21_11.rst
+++ b/doc/guides/rel_notes/release_21_11.rst
@@ -55,6 +55,11 @@ New Features
Also, make sure to start the actual text at the margin.
=======================================================
+* **Added vhost API to get the number of inflight packets.**
+
+ Added an API which can get the number of inflight packets in
+ vhost async data path without using lock.
+
* **Enabled new devargs parser.**
* Enabled devargs syntax
diff --git a/lib/vhost/rte_vhost_async.h b/lib/vhost/rte_vhost_async.h
index b25ff446f7..0af414bf78 100644
--- a/lib/vhost/rte_vhost_async.h
+++ b/lib/vhost/rte_vhost_async.h
@@ -246,6 +246,20 @@ uint16_t rte_vhost_poll_enqueue_completed(int vid,
uint16_t queue_id,
__rte_experimental
int rte_vhost_async_get_inflight(int vid, uint16_t queue_id);
+/**
+ * This function is lock-free version to return the amount of in-flight
+ * packets for the vhost queue which uses async channel acceleration.
+ *
+ * @param vid
+ * id of vhost device to enqueue data
+ * @param queue_id
+ * queue id to enqueue data
+ * @return
+ * the amount of in-flight packets on success; -1 on failure
+ */
+__rte_experimental
+int rte_vhost_async_get_inflight_thread_unsafe(int vid, uint16_t queue_id);
+
/**
* This function checks async completion status and clear packets for
* a specific vhost device queue. Packets which are inflight will be
diff --git a/lib/vhost/version.map b/lib/vhost/version.map
index c92a9d4962..b150dc408d 100644
--- a/lib/vhost/version.map
+++ b/lib/vhost/version.map
@@ -85,4 +85,7 @@ EXPERIMENTAL {
rte_vhost_async_channel_register_thread_unsafe;
rte_vhost_async_channel_unregister_thread_unsafe;
rte_vhost_clear_queue_thread_unsafe;
+
+ #added in 21.11
+ rte_vhost_async_get_inflight_thread_unsafe;
};
diff --git a/lib/vhost/vhost.c b/lib/vhost/vhost.c
index 355ff37651..24ae1025ea 100644
--- a/lib/vhost/vhost.c
+++ b/lib/vhost/vhost.c
@@ -1886,5 +1886,31 @@ int rte_vhost_async_get_inflight(int vid, uint16_t
queue_id)
return ret;
}
+int
+rte_vhost_async_get_inflight_thread_unsafe(int vid, uint16_t queue_id)
+{
+ struct vhost_virtqueue *vq;
+ struct virtio_net *dev = get_device(vid);
+ int ret = -1;
+
+ if (dev == NULL)
+ return ret;
+
+ if (queue_id >= VHOST_MAX_VRING)
+ return ret;
+
+ vq = dev->virtqueue[queue_id];
+
+ if (vq == NULL)
+ return ret;
+
+ if (!vq->async_registered)
+ return ret;
+
+ ret = vq->async_pkts_inflight_n;
+
+ return ret;
+}
+
RTE_LOG_REGISTER_SUFFIX(vhost_config_log_level, config, INFO);
RTE_LOG_REGISTER_SUFFIX(vhost_data_log_level, data, WARNING);
--
2.17.1
