[dpdk-dev] [PATCH v5 5/5] doc: update doc for try drain API in vhost lib

[Cheng Jiang <cheng1.jiang@intel.com>]

update the program guide and release notes for try drain API in vhost
lib.

Signed-off-by: Cheng Jiang <cheng1.jiang@intel.com>
---
 doc/guides/prog_guide/vhost_lib.rst    | 5 +++++
 doc/guides/rel_notes/release_21_08.rst | 5 +++++
 2 files changed, 10 insertions(+)

diff --git a/doc/guides/prog_guide/vhost_lib.rst b/doc/guides/prog_guide/vhost_lib.rst
index d18fb98910..85aabc4a75 100644
--- a/doc/guides/prog_guide/vhost_lib.rst
+++ b/doc/guides/prog_guide/vhost_lib.rst
@@ -281,6 +281,11 @@ The following is an overview of some key Vhost API functions:
   Poll enqueue completion status from async data path. Completed packets
   are returned to applications through ``pkts``.
 
+* ``rte_vhost_try_drain_queue_thread_unsafe(vid, queue_id, **pkts, count, times)``
+
+  Try to drain in-flight packets which are submitted to DMA engine in vhost async data
+  path. Completed packets are returned to applications through ``pkts``.
+
 Vhost-user Implementations
 --------------------------
 
diff --git a/doc/guides/rel_notes/release_21_08.rst b/doc/guides/rel_notes/release_21_08.rst
index 6a902ef9ac..c38e358cf9 100644
--- a/doc/guides/rel_notes/release_21_08.rst
+++ b/doc/guides/rel_notes/release_21_08.rst
@@ -117,6 +117,11 @@ New Features
   The experimental PMD power management API now supports managing
   multiple Ethernet Rx queues per lcore.
 
+* **Added try drain API in vhost library.**
+
+  Added an API which can try to drain the inflight packets submitted to DMA
+  engine in vhost async data path.
+
 
 Removed Items
 -------------
-- 
2.29.2