From: Xuan Ding <[email protected]> This patch updates the correct usage for async enqueue APIs. The rte_vhost_poll_enqueue_completed() needs to be called in time to notify the guest of completed packets and avoid packet loss.
Signed-off-by: Xuan Ding <[email protected]> --- v2: * refine doc and commit log --- doc/guides/prog_guide/vhost_lib.rst | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/doc/guides/prog_guide/vhost_lib.rst b/doc/guides/prog_guide/vhost_lib.rst index cd3f6caa9a..628db3fc38 100644 --- a/doc/guides/prog_guide/vhost_lib.rst +++ b/doc/guides/prog_guide/vhost_lib.rst @@ -480,6 +480,14 @@ the same vring with their own DMA virtual channels. Besides, the number of DMA devices is limited. For the purpose of scaling, it's necessary to support sharing DMA channels among vrings. +* Async enqueue API usage + + In async enqueue path, rte_vhost_poll_enqueue_completed() needs to be + called in time to notify the guest of DMA copy completed packets. + Moreover, calling rte_vhost_submit_enqueue_burst() all the time but + not poll completed will cause the DMA ring to be full, which will + result in packet loss eventually. + Recommended IOVA mode in async datapath --------------------------------------- -- 2.17.1
