Hi Xuan, > -----Original Message----- > From: Ding, Xuan <xuan.d...@intel.com> > Sent: Monday, May 16, 2022 10:43 AM > To: maxime.coque...@redhat.com; Xia, Chenbo <chenbo....@intel.com> > Cc: dev@dpdk.org; Hu, Jiayu <jiayu...@intel.com>; Jiang, Cheng1 > <cheng1.ji...@intel.com>; Pai G, Sunil <sunil.pa...@intel.com>; > lian...@liangbit.com; Ding, Xuan <xuan.d...@intel.com>; Wang, YuanX > <yuanx.w...@intel.com> > Subject: [PATCH v7 4/5] vhost: support async dequeue for split ring > > From: Xuan Ding <xuan.d...@intel.com> > > This patch implements asynchronous dequeue data path for vhost split ring, > a new API rte_vhost_async_try_dequeue_burst() is introduced. > > Signed-off-by: Xuan Ding <xuan.d...@intel.com> > Signed-off-by: Yuan Wang <yuanx.w...@intel.com> > Tested-by: Yvonne Yang <yvonnex.y...@intel.com> > Reviewed-by: Maxime Coquelin <maxime.coque...@redhat.com> > --- > doc/guides/prog_guide/vhost_lib.rst | 7 + > doc/guides/rel_notes/release_22_07.rst | 5 + > lib/vhost/rte_vhost_async.h | 37 +++ > lib/vhost/version.map | 2 +- > lib/vhost/virtio_net.c | 337 +++++++++++++++++++++++++ > 5 files changed, 387 insertions(+), 1 deletion(-) > > diff --git a/doc/guides/prog_guide/vhost_lib.rst > b/doc/guides/prog_guide/vhost_lib.rst > index f287b76ebf..09c1c24b48 100644 > --- a/doc/guides/prog_guide/vhost_lib.rst > +++ b/doc/guides/prog_guide/vhost_lib.rst > @@ -282,6 +282,13 @@ The following is an overview of some key Vhost API > functions: > Clear inflight packets which are submitted to DMA engine in vhost async > data > path. Completed packets are returned to applications through ``pkts``. > > +* ``rte_vhost_async_try_dequeue_burst(int vid, uint16_t queue_id, > + struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, uint16_t count, > + int *nr_inflight, uint16_t dma_id, uint16_t vchan_id)``
In dmadev library, dma_id is int16_t, rather than uint16_t. > + > + Receives (dequeues) ``count`` packets from guest to host in async > + data path, and stored them at ``pkts``. > + > Vhost-user Implementations > -------------------------- > > diff --git a/doc/guides/rel_notes/release_22_07.rst > b/doc/guides/rel_notes/release_22_07.rst > index 88b1e478d4..564d88623e 100644 > --- a/doc/guides/rel_notes/release_22_07.rst > +++ b/doc/guides/rel_notes/release_22_07.rst > @@ -70,6 +70,11 @@ New Features > Added an API which can get the number of inflight packets in > vhost async data path without using lock. > > +* **Added vhost async dequeue API to receive pkts from guest.** > + > + Added vhost async dequeue API which can leverage DMA devices to > + accelerate receiving pkts from guest. > + > Removed Items > ------------- > > diff --git a/lib/vhost/rte_vhost_async.h b/lib/vhost/rte_vhost_async.h index > 70234debf9..2789492e38 100644 > --- a/lib/vhost/rte_vhost_async.h > +++ b/lib/vhost/rte_vhost_async.h > @@ -204,6 +204,43 @@ uint16_t rte_vhost_clear_queue_thread_unsafe(int > vid, uint16_t queue_id, __rte_experimental int > rte_vhost_async_dma_configure(int16_t dma_id, uint16_t vchan_id); > > +/** > + * @warning > + * @b EXPERIMENTAL: this API may change, or be removed, without prior > +notice > + * > + * This function tries to receive packets from the guest with > +offloading > + * copies to the async channel. The packets that are transfer completed In rte_vhost_async.h, DMA vChannel is referred as async channel or async copy engine. But I think it's better to replace all with DMA vChannel to be consistent with DPDK. > + * are returned in "pkts". The other packets that their copies are > +submitted to > + * the async channel but not completed are called "in-flight packets". > + * This function will not return in-flight packets until their copies > +are > + * completed by the async channel. > + * > + * @param vid > + * ID of vhost device to dequeue data > + * @param queue_id > + * ID of virtqueue to dequeue data > + * @param mbuf_pool > + * Mbuf_pool where host mbuf is allocated > + * @param pkts > + * Blank array to keep successfully dequeued packets > + * @param count > + * Size of the packet array > + * @param nr_inflight > + * >= 0: The amount of in-flight packets Better to add more descriptions about the meaning of "nr_inflight". Thanks, Jiayu
