[v7,2/4] vhost: add support for packed ring in async vhost

Message ID 20210414061343.54919-3-Cheng1.jiang@intel.com (mailing list archive)
State Superseded, archived
Delegated to: Maxime Coquelin
Headers
Series add support for packed ring in async vhost |

Checks

Context Check Description
ci/checkpatch success coding style OK

Commit Message

Jiang, Cheng1 April 14, 2021, 6:13 a.m. UTC
  For now async vhost data path only supports split ring. This patch
enables packed ring in async vhost data path to make async vhost
compatible with virtio 1.1 spec.

Signed-off-by: Cheng Jiang <Cheng1.jiang@intel.com>
---
 lib/librte_vhost/rte_vhost_async.h |   1 +
 lib/librte_vhost/vhost.c           |  49 ++--
 lib/librte_vhost/vhost.h           |  15 +-
 lib/librte_vhost/virtio_net.c      | 432 +++++++++++++++++++++++++++--
 4 files changed, 456 insertions(+), 41 deletions(-)
  

Comments

Maxime Coquelin April 14, 2021, 1:40 p.m. UTC | #1
On 4/14/21 8:13 AM, Cheng Jiang wrote:
> For now async vhost data path only supports split ring. This patch
> enables packed ring in async vhost data path to make async vhost
> compatible with virtio 1.1 spec.
> 
> Signed-off-by: Cheng Jiang <Cheng1.jiang@intel.com>
> ---
>  lib/librte_vhost/rte_vhost_async.h |   1 +
>  lib/librte_vhost/vhost.c           |  49 ++--
>  lib/librte_vhost/vhost.h           |  15 +-
>  lib/librte_vhost/virtio_net.c      | 432 +++++++++++++++++++++++++++--
>  4 files changed, 456 insertions(+), 41 deletions(-)
> 
> diff --git a/lib/librte_vhost/rte_vhost_async.h b/lib/librte_vhost/rte_vhost_async.h
> index c855ff875..6faa31f5a 100644
> --- a/lib/librte_vhost/rte_vhost_async.h
> +++ b/lib/librte_vhost/rte_vhost_async.h
> @@ -89,6 +89,7 @@ struct rte_vhost_async_channel_ops {
>  struct async_inflight_info {
>  	struct rte_mbuf *mbuf;
>  	uint16_t descs; /* num of descs inflight */
> +	uint16_t nr_buffers; /* num of buffers inflight for packed ring */
>  };
>  
>  /**
> diff --git a/lib/librte_vhost/vhost.c b/lib/librte_vhost/vhost.c
> index a70fe01d8..f509186c6 100644
> --- a/lib/librte_vhost/vhost.c
> +++ b/lib/librte_vhost/vhost.c
> @@ -338,19 +338,22 @@ cleanup_device(struct virtio_net *dev, int destroy)
>  }
>  
>  static void
> -vhost_free_async_mem(struct vhost_virtqueue *vq)
> +vhost_free_async_mem(struct virtio_net *dev, struct vhost_virtqueue *vq)
>  {
> -	if (vq->async_pkts_info)
> -		rte_free(vq->async_pkts_info);
> -	if (vq->async_descs_split)
> +	rte_free(vq->async_pkts_info);
> +
> +	if (vq_is_packed(dev)) {
> +		rte_free(vq->async_buffers_packed);
> +		vq->async_buffers_packed = NULL;
> +	} else {

Doing this is not necessary:

	rte_free(vq->async_buffers_packed);
	vq->async_buffers_packed = NULL;
	rte_free(vq->async_descs_split);
	vq->async_descs_split = NULL;

Above will just work and will avoid adding dev parameter.


>  		rte_free(vq->async_descs_split);
> -	if (vq->it_pool)
> -		rte_free(vq->it_pool);
> -	if (vq->vec_pool)
> -		rte_free(vq->vec_pool);
> +		vq->async_descs_split = NULL;
> +	}
> +
> +	rte_free(vq->it_pool);
> +	rte_free(vq->vec_pool);
>  
>  	vq->async_pkts_info = NULL;
> -	vq->async_descs_split = NULL;
>  	vq->it_pool = NULL;
>  	vq->vec_pool = NULL;
>  }
> @@ -360,10 +363,10 @@ free_vq(struct virtio_net *dev, struct vhost_virtqueue *vq)
>  {
>  	if (vq_is_packed(dev))
>  		rte_free(vq->shadow_used_packed);
> -	else {
> +	else
>  		rte_free(vq->shadow_used_split);
> -		vhost_free_async_mem(vq);
> -	}
> +
> +	vhost_free_async_mem(dev, vq);
>  	rte_free(vq->batch_copy_elems);
>  	if (vq->iotlb_pool)
>  		rte_mempool_free(vq->iotlb_pool);
> @@ -1626,10 +1629,9 @@ int rte_vhost_async_channel_register(int vid, uint16_t queue_id,
>  	if (unlikely(vq == NULL || !dev->async_copy))
>  		return -1;
>  
> -	/* packed queue is not supported */
> -	if (unlikely(vq_is_packed(dev) || !f.async_inorder)) {
> +	if (unlikely(!f.async_inorder)) {
>  		VHOST_LOG_CONFIG(ERR,
> -			"async copy is not supported on packed queue or non-inorder mode "
> +			"async copy is not supported on non-inorder mode "
>  			"(vid %d, qid: %d)\n", vid, queue_id);
>  		return -1;
>  	}
> @@ -1667,12 +1669,19 @@ int rte_vhost_async_channel_register(int vid, uint16_t queue_id,
>  	vq->vec_pool = rte_malloc_socket(NULL,
>  			VHOST_MAX_ASYNC_VEC * sizeof(struct iovec),
>  			RTE_CACHE_LINE_SIZE, node);
> -	vq->async_descs_split = rte_malloc_socket(NULL,
> +	if (vq_is_packed(dev)) {
> +		vq->async_buffers_packed = rte_malloc_socket(NULL,
> +			vq->size * sizeof(struct vring_used_elem_packed),
> +			RTE_CACHE_LINE_SIZE, node);
> +	} else {
> +		vq->async_descs_split = rte_malloc_socket(NULL,
>  			vq->size * sizeof(struct vring_used_elem),
>  			RTE_CACHE_LINE_SIZE, node);
> -	if (!vq->async_descs_split || !vq->async_pkts_info ||
> -		!vq->it_pool || !vq->vec_pool) {
> -		vhost_free_async_mem(vq);
> +	}
> +
> +	if (!vq->async_buffers_packed || !vq->async_descs_split ||
> +		!vq->async_pkts_info || !vq->it_pool || !vq->vec_pool) {

Not really than of this error handling. Checking after every malloc if
it suceed would be cleaner.

> +		vhost_free_async_mem(dev, vq);
>  		VHOST_LOG_CONFIG(ERR,
>  				"async register failed: cannot allocate memory for vq data "
>  				"(vid %d, qid: %d)\n", vid, queue_id);
> @@ -1728,7 +1737,7 @@ int rte_vhost_async_channel_unregister(int vid, uint16_t queue_id)
>  		goto out;
>  	}
>  
> -	vhost_free_async_mem(vq);
> +	vhost_free_async_mem(dev, vq);
>  
>  	vq->async_ops.transfer_data = NULL;
>  	vq->async_ops.check_completed_copies = NULL;
> diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h
> index f628714c2..673335217 100644
> --- a/lib/librte_vhost/vhost.h
> +++ b/lib/librte_vhost/vhost.h
> @@ -201,9 +201,18 @@ struct vhost_virtqueue {
>  	uint16_t	async_pkts_idx;
>  	uint16_t	async_pkts_inflight_n;
>  	uint16_t	async_last_pkts_n;
> -	struct vring_used_elem  *async_descs_split;
> -	uint16_t async_desc_idx;
> -	uint16_t last_async_desc_idx;
> +	union {
> +		struct vring_used_elem  *async_descs_split;
> +		struct vring_used_elem_packed *async_buffers_packed;
> +	};
> +	union {
> +		uint16_t async_desc_idx;
> +		uint16_t async_packed_buffer_idx;
> +	};
> +	union {
> +		uint16_t last_async_desc_idx;
> +		uint16_t last_async_buffer_idx;
> +	};

Looks almost good to me now, thanks for doing the change.
Only minor issue is the naming which is not consistent in the different
fields. Sometimes it contains split or packed, sometimes not.

Maxime
  
Hu, Jiayu April 15, 2021, 2:02 a.m. UTC | #2
Hi Cheng,

> -----Original Message-----
> From: Jiang, Cheng1 <cheng1.jiang@intel.com>
> Sent: Wednesday, April 14, 2021 2:14 PM
> To: maxime.coquelin@redhat.com; Xia, Chenbo <chenbo.xia@intel.com>
> Cc: dev@dpdk.org; Hu, Jiayu <jiayu.hu@intel.com>; Yang, YvonneX
> <yvonnex.yang@intel.com>; Wang, Yinan <yinan.wang@intel.com>; Liu,
> Yong <yong.liu@intel.com>; Jiang, Cheng1 <cheng1.jiang@intel.com>
> Subject: [PATCH v7 2/4] vhost: add support for packed ring in async vhost
> 
> For now async vhost data path only supports split ring. This patch
> enables packed ring in async vhost data path to make async vhost
> compatible with virtio 1.1 spec.
> 
> Signed-off-by: Cheng Jiang <Cheng1.jiang@intel.com>
> ---
>  lib/librte_vhost/rte_vhost_async.h |   1 +
>  lib/librte_vhost/vhost.c           |  49 ++--
>  lib/librte_vhost/vhost.h           |  15 +-
>  lib/librte_vhost/virtio_net.c      | 432 +++++++++++++++++++++++++++--
>  4 files changed, 456 insertions(+), 41 deletions(-)
> 
> diff --git a/lib/librte_vhost/rte_vhost_async.h
> b/lib/librte_vhost/rte_vhost_async.h
> index c855ff875..6faa31f5a 100644
> --- a/lib/librte_vhost/rte_vhost_async.h
> +++ b/lib/librte_vhost/rte_vhost_async.h
> @@ -89,6 +89,7 @@ struct rte_vhost_async_channel_ops {
>  struct async_inflight_info {
>  	struct rte_mbuf *mbuf;
>  	uint16_t descs; /* num of descs inflight */
> +	uint16_t nr_buffers; /* num of buffers inflight for packed ring */
>  };
> 
>  /**
> diff --git a/lib/librte_vhost/vhost.c b/lib/librte_vhost/vhost.c
> index a70fe01d8..f509186c6 100644
> --- a/lib/librte_vhost/vhost.c
> +++ b/lib/librte_vhost/vhost.c
> @@ -338,19 +338,22 @@ cleanup_device(struct virtio_net *dev, int destroy)
>  }
> 
>  static void
> -vhost_free_async_mem(struct vhost_virtqueue *vq)
> +vhost_free_async_mem(struct virtio_net *dev, struct vhost_virtqueue *vq)
>  {
> -	if (vq->async_pkts_info)
> -		rte_free(vq->async_pkts_info);
> -	if (vq->async_descs_split)
> +	rte_free(vq->async_pkts_info);
> +
> +	if (vq_is_packed(dev)) {
> +		rte_free(vq->async_buffers_packed);
> +		vq->async_buffers_packed = NULL;
> +	} else {
>  		rte_free(vq->async_descs_split);
> -	if (vq->it_pool)
> -		rte_free(vq->it_pool);
> -	if (vq->vec_pool)
> -		rte_free(vq->vec_pool);
> +		vq->async_descs_split = NULL;
> +	}
> +
> +	rte_free(vq->it_pool);
> +	rte_free(vq->vec_pool);
> 
>  	vq->async_pkts_info = NULL;
> -	vq->async_descs_split = NULL;
>  	vq->it_pool = NULL;
>  	vq->vec_pool = NULL;
>  }
> @@ -360,10 +363,10 @@ free_vq(struct virtio_net *dev, struct
> vhost_virtqueue *vq)
>  {
>  	if (vq_is_packed(dev))
>  		rte_free(vq->shadow_used_packed);
> -	else {
> +	else
>  		rte_free(vq->shadow_used_split);
> -		vhost_free_async_mem(vq);
> -	}
> +
> +	vhost_free_async_mem(dev, vq);
>  	rte_free(vq->batch_copy_elems);
>  	if (vq->iotlb_pool)
>  		rte_mempool_free(vq->iotlb_pool);
> @@ -1626,10 +1629,9 @@ int rte_vhost_async_channel_register(int vid,
> uint16_t queue_id,
>  	if (unlikely(vq == NULL || !dev->async_copy))
>  		return -1;
> 
> -	/* packed queue is not supported */
> -	if (unlikely(vq_is_packed(dev) || !f.async_inorder)) {
> +	if (unlikely(!f.async_inorder)) {
>  		VHOST_LOG_CONFIG(ERR,
> -			"async copy is not supported on packed queue or
> non-inorder mode "
> +			"async copy is not supported on non-inorder mode "
>  			"(vid %d, qid: %d)\n", vid, queue_id);
>  		return -1;
>  	}
> @@ -1667,12 +1669,19 @@ int rte_vhost_async_channel_register(int vid,
> uint16_t queue_id,
>  	vq->vec_pool = rte_malloc_socket(NULL,
>  			VHOST_MAX_ASYNC_VEC * sizeof(struct iovec),
>  			RTE_CACHE_LINE_SIZE, node);
> -	vq->async_descs_split = rte_malloc_socket(NULL,
> +	if (vq_is_packed(dev)) {
> +		vq->async_buffers_packed = rte_malloc_socket(NULL,
> +			vq->size * sizeof(struct vring_used_elem_packed),
> +			RTE_CACHE_LINE_SIZE, node);
> +	} else {
> +		vq->async_descs_split = rte_malloc_socket(NULL,
>  			vq->size * sizeof(struct vring_used_elem),
>  			RTE_CACHE_LINE_SIZE, node);
> -	if (!vq->async_descs_split || !vq->async_pkts_info ||
> -		!vq->it_pool || !vq->vec_pool) {
> -		vhost_free_async_mem(vq);
> +	}
> +
> +	if (!vq->async_buffers_packed || !vq->async_descs_split ||
async_buffers_packed and async_descs_split are two members of a union.
Like the way processed in vhost_free_async_mem(), do you think it's better
to check if they are NULL in if-else respectively?

> +		!vq->async_pkts_info || !vq->it_pool || !vq->vec_pool) {
> +		vhost_free_async_mem(dev, vq);
>  		VHOST_LOG_CONFIG(ERR,
>  				"async register failed: cannot allocate
> memory for vq data "
>  				"(vid %d, qid: %d)\n", vid, queue_id);
> @@ -1728,7 +1737,7 @@ int rte_vhost_async_channel_unregister(int vid,
> uint16_t queue_id)
>  		goto out;
>  	}
> 
> -	vhost_free_async_mem(vq);
> +	vhost_free_async_mem(dev, vq);
> 
>  	vq->async_ops.transfer_data = NULL;
>  	vq->async_ops.check_completed_copies = NULL;
> diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h
> index f628714c2..673335217 100644
> --- a/lib/librte_vhost/vhost.h
> +++ b/lib/librte_vhost/vhost.h
> @@ -201,9 +201,18 @@ struct vhost_virtqueue {
>  	uint16_t	async_pkts_idx;
>  	uint16_t	async_pkts_inflight_n;
>  	uint16_t	async_last_pkts_n;
> -	struct vring_used_elem  *async_descs_split;
> -	uint16_t async_desc_idx;
> -	uint16_t last_async_desc_idx;
> +	union {
> +		struct vring_used_elem  *async_descs_split;
> +		struct vring_used_elem_packed *async_buffers_packed;
> +	};
> +	union {
> +		uint16_t async_desc_idx;
> +		uint16_t async_packed_buffer_idx;
> +	};
> +	union {
> +		uint16_t last_async_desc_idx;
> +		uint16_t last_async_buffer_idx;
> +	};
> 
>  	/* vq async features */
>  	bool		async_inorder;
> diff --git a/lib/librte_vhost/virtio_net.c b/lib/librte_vhost/virtio_net.c
> index 438bdafd1..54e11e3a5 100644
> --- a/lib/librte_vhost/virtio_net.c
> +++ b/lib/librte_vhost/virtio_net.c
> @@ -363,14 +363,14 @@
> vhost_shadow_dequeue_single_packed_inorder(struct vhost_virtqueue *vq,
>  }
> 
>  static __rte_always_inline void
> -vhost_shadow_enqueue_single_packed(struct virtio_net *dev,
> -				   struct vhost_virtqueue *vq,
> -				   uint32_t len[],
> -				   uint16_t id[],
> -				   uint16_t count[],
> +vhost_shadow_enqueue_packed(struct vhost_virtqueue *vq,
> +				   uint32_t *len,
> +				   uint16_t *id,
> +				   uint16_t *count,
>  				   uint16_t num_buffers)
>  {
>  	uint16_t i;
> +
>  	for (i = 0; i < num_buffers; i++) {
>  		/* enqueue shadow flush action aligned with batch num */
>  		if (!vq->shadow_used_idx)
> @@ -382,6 +382,17 @@ vhost_shadow_enqueue_single_packed(struct
> virtio_net *dev,
>  		vq->shadow_aligned_idx += count[i];
>  		vq->shadow_used_idx++;
>  	}
> +}
> +
> +static __rte_always_inline void
> +vhost_shadow_enqueue_single_packed(struct virtio_net *dev,
> +				   struct vhost_virtqueue *vq,
> +				   uint32_t *len,
> +				   uint16_t *id,
> +				   uint16_t *count,
> +				   uint16_t num_buffers)
> +{
> +	vhost_shadow_enqueue_packed(vq, len, id, count, num_buffers);
> 
>  	if (vq->shadow_aligned_idx >= PACKED_BATCH_SIZE) {
>  		do_data_copy_enqueue(dev, vq);
> @@ -1474,6 +1485,23 @@ store_dma_desc_info_split(struct
> vring_used_elem *s_ring, struct vring_used_elem
>  	}
>  }
> 
> +static __rte_always_inline void
> +store_dma_desc_info_packed(struct vring_used_elem_packed *s_ring,
> +		struct vring_used_elem_packed *d_ring,
> +		uint16_t ring_size, uint16_t s_idx, uint16_t d_idx, uint16_t
> count)
> +{
> +	uint16_t elem_size = sizeof(struct vring_used_elem_packed);
> +
> +	if (d_idx + count <= ring_size) {
> +		rte_memcpy(d_ring + d_idx, s_ring + s_idx, count *
> elem_size);
> +	} else {
> +		uint16_t size = ring_size - d_idx;
> +
> +		rte_memcpy(d_ring + d_idx, s_ring + s_idx, size * elem_size);
> +		rte_memcpy(d_ring, s_ring + s_idx + size, (count - size) *
> elem_size);
> +	}
> +}
> +
>  static __rte_noinline uint32_t
>  virtio_dev_rx_async_submit_split(struct virtio_net *dev,
>  	struct vhost_virtqueue *vq, uint16_t queue_id,
> @@ -1641,6 +1669,330 @@ virtio_dev_rx_async_submit_split(struct
> virtio_net *dev,
>  	return pkt_idx;
>  }
> 
> +static __rte_always_inline void
> +vhost_update_used_packed(struct vhost_virtqueue *vq,
> +			struct vring_used_elem_packed *shadow_ring,
> +			uint16_t count)
> +{
> +	int i;
> +	uint16_t used_idx = vq->last_used_idx;
> +	uint16_t head_idx = vq->last_used_idx;
> +	uint16_t head_flags = 0;
> +
> +	if (count == 0)
> +		return;
> +
> +	/* Split loop in two to save memory barriers */
> +	for (i = 0; i < count; i++) {
> +		vq->desc_packed[used_idx].id = shadow_ring[i].id;
> +		vq->desc_packed[used_idx].len = shadow_ring[i].len;
> +
> +		used_idx += shadow_ring[i].count;
> +		if (used_idx >= vq->size)
> +			used_idx -= vq->size;
> +	}
> +
> +	/* The ordering for storing desc flags needs to be enforced. */
> +	rte_atomic_thread_fence(__ATOMIC_RELEASE);
> +
> +	for (i = 0; i < count; i++) {
> +		uint16_t flags;
> +
> +		if (vq->shadow_used_packed[i].len)
> +			flags = VRING_DESC_F_WRITE;
> +		else
> +			flags = 0;
> +
> +		if (vq->used_wrap_counter) {
> +			flags |= VRING_DESC_F_USED;
> +			flags |= VRING_DESC_F_AVAIL;
> +		} else {
> +			flags &= ~VRING_DESC_F_USED;
> +			flags &= ~VRING_DESC_F_AVAIL;
> +		}
> +
> +		if (i > 0) {
> +			vq->desc_packed[vq->last_used_idx].flags = flags;
> +
No need a blank line above.

> +		} else {
> +			head_idx = vq->last_used_idx;
> +			head_flags = flags;
> +		}
> +
> +		vq_inc_last_used_packed(vq, shadow_ring[i].count);
> +	}
> +
> +	vq->desc_packed[head_idx].flags = head_flags;
> +}
> +
> +static __rte_always_inline int
> +vhost_enqueue_async_single_packed(struct virtio_net *dev,
> +			    struct vhost_virtqueue *vq,
> +			    struct rte_mbuf *pkt,
> +			    struct buf_vector *buf_vec,
> +			    uint16_t *nr_descs,
> +			    uint16_t *nr_buffers,
> +			    struct vring_packed_desc *async_descs,
> +			    struct iovec *src_iovec, struct iovec *dst_iovec,
> +			    struct rte_vhost_iov_iter *src_it,
> +			    struct rte_vhost_iov_iter *dst_it)
> +{
> +	uint16_t nr_vec = 0;
> +	uint16_t avail_idx = vq->last_avail_idx;
> +	uint16_t max_tries, tries = 0;
> +	uint16_t buf_id = 0;
> +	uint32_t len = 0;
> +	uint16_t desc_count = 0;
> +	uint32_t size = pkt->pkt_len + sizeof(struct
> virtio_net_hdr_mrg_rxbuf);
> +	uint32_t buffer_len[vq->size];
> +	uint16_t buffer_buf_id[vq->size];
> +	uint16_t buffer_desc_count[vq->size];
> +	*nr_buffers = 0;
> +
> +	if (rxvq_is_mergeable(dev))
> +		max_tries = vq->size - 1;
> +	else
> +		max_tries = 1;
> +
> +	while (size > 0) {
> +		/*
> +		 * if we tried all available ring items, and still
> +		 * can't get enough buf, it means something abnormal
> +		 * happened.
> +		 */
> +		if (unlikely(++tries > max_tries))
> +			return -1;
> +
> +		if (unlikely(fill_vec_buf_packed(dev, vq, avail_idx,
> &desc_count, buf_vec, &nr_vec,
> +						&buf_id, &len,
> VHOST_ACCESS_RW) < 0))
> +			return -1;
> +
> +		len = RTE_MIN(len, size);
> +		size -= len;
> +
> +		buffer_len[*nr_buffers] = len;
> +		buffer_buf_id[*nr_buffers] = buf_id;
> +		buffer_desc_count[*nr_buffers] = desc_count;
> +		*nr_buffers += 1;
> +
> +		*nr_descs += desc_count;
> +		avail_idx += desc_count;
> +		if (avail_idx >= vq->size)
> +			avail_idx -= vq->size;
> +	}
> +
> +	if (async_mbuf_to_desc(dev, vq, pkt, buf_vec, nr_vec, *nr_buffers,
> src_iovec, dst_iovec,
> +			src_it, dst_it) < 0)
> +		return -1;
> +	/* store descriptors for DMA */
> +	if (avail_idx >= *nr_descs) {
> +		rte_memcpy(async_descs, &vq->desc_packed[vq-
> >last_avail_idx],
> +			*nr_descs * sizeof(struct vring_packed_desc));
> +	} else {
> +		uint16_t nr_copy = vq->size - vq->last_avail_idx;
> +		rte_memcpy(async_descs, &vq->desc_packed[vq-
> >last_avail_idx],
> +			nr_copy * sizeof(struct vring_packed_desc));
> +		rte_memcpy(async_descs + nr_copy, vq->desc_packed,
> +			(*nr_descs - nr_copy) * sizeof(struct
> vring_packed_desc));
> +	}
> +
> +	vhost_shadow_enqueue_packed(vq, buffer_len, buffer_buf_id,
> buffer_desc_count, *nr_buffers);
> +
> +	return 0;
> +}
> +
> +static __rte_always_inline int16_t
> +virtio_dev_rx_async_single_packed(struct virtio_net *dev, struct
> vhost_virtqueue *vq,
> +			    struct rte_mbuf *pkt, uint16_t *nr_descs, uint16_t
> *nr_buffers,
> +			    struct vring_packed_desc *async_descs,
> +			    struct iovec *src_iovec, struct iovec *dst_iovec,
> +			    struct rte_vhost_iov_iter *src_it, struct
> rte_vhost_iov_iter *dst_it)
> +{
> +	struct buf_vector buf_vec[BUF_VECTOR_MAX];
> +	*nr_descs = 0;
> +	*nr_buffers = 0;
> +
> +	if (unlikely(vhost_enqueue_async_single_packed(dev, vq, pkt,
> buf_vec, nr_descs, nr_buffers,
> +						 async_descs, src_iovec,
> dst_iovec,
> +						 src_it, dst_it) < 0)) {
> +		VHOST_LOG_DATA(DEBUG, "(%d) failed to get enough desc
> from vring\n", dev->vid);
> +		return -1;
> +	}
> +
> +	VHOST_LOG_DATA(DEBUG, "(%d) current index %d | end
> index %d\n",
> +			dev->vid, vq->last_avail_idx, vq->last_avail_idx +
> *nr_descs);
> +
> +	return 0;
> +}
> +
> +static __rte_always_inline void
> +dma_error_handler_packed(struct vhost_virtqueue *vq, struct
> vring_packed_desc *async_descs,
> +			uint16_t async_descs_idx, uint16_t slot_idx, uint32_t
> nr_err,
> +			uint32_t *pkt_idx, uint32_t *num_async_pkts,
> uint32_t *num_done_pkts)
> +{
> +	uint16_t descs_err = 0;
> +	uint16_t buffers_err = 0;
> +	struct async_inflight_info *pkts_info = vq->async_pkts_info;
> +
> +	*num_async_pkts -= nr_err;
> +	*pkt_idx -= nr_err;
> +	/* calculate the sum of buffers and descs of DMA-error packets. */
> +	while (nr_err-- > 0) {
> +		descs_err += pkts_info[slot_idx % vq->size].descs;
I notice there are several parts using "%" to wrap around index, but
existed code uses "& (vq->size - 1)" instead. I think it's better to keep
it consistent.

Thanks,
Jiayu
  
Jiang, Cheng1 April 15, 2021, 5:42 a.m. UTC | #3
Hi Maxime,

> -----Original Message-----
> From: Maxime Coquelin <maxime.coquelin@redhat.com>
> Sent: Wednesday, April 14, 2021 9:41 PM
> To: Jiang, Cheng1 <cheng1.jiang@intel.com>; Xia, Chenbo
> <chenbo.xia@intel.com>
> Cc: dev@dpdk.org; Hu, Jiayu <jiayu.hu@intel.com>; Yang, YvonneX
> <yvonnex.yang@intel.com>; Wang, Yinan <yinan.wang@intel.com>; Liu,
> Yong <yong.liu@intel.com>
> Subject: Re: [PATCH v7 2/4] vhost: add support for packed ring in async vhost
> 
> 
> 
> On 4/14/21 8:13 AM, Cheng Jiang wrote:
> > For now async vhost data path only supports split ring. This patch
> > enables packed ring in async vhost data path to make async vhost
> > compatible with virtio 1.1 spec.
> >
> > Signed-off-by: Cheng Jiang <Cheng1.jiang@intel.com>
> > ---
> >  lib/librte_vhost/rte_vhost_async.h |   1 +
> >  lib/librte_vhost/vhost.c           |  49 ++--
> >  lib/librte_vhost/vhost.h           |  15 +-
> >  lib/librte_vhost/virtio_net.c      | 432 +++++++++++++++++++++++++++--
> >  4 files changed, 456 insertions(+), 41 deletions(-)
> >
> > diff --git a/lib/librte_vhost/rte_vhost_async.h
> > b/lib/librte_vhost/rte_vhost_async.h
> > index c855ff875..6faa31f5a 100644
> > --- a/lib/librte_vhost/rte_vhost_async.h
> > +++ b/lib/librte_vhost/rte_vhost_async.h
> > @@ -89,6 +89,7 @@ struct rte_vhost_async_channel_ops {  struct
> > async_inflight_info {
> >  	struct rte_mbuf *mbuf;
> >  	uint16_t descs; /* num of descs inflight */
> > +	uint16_t nr_buffers; /* num of buffers inflight for packed ring */
> >  };
> >
> >  /**
> > diff --git a/lib/librte_vhost/vhost.c b/lib/librte_vhost/vhost.c index
> > a70fe01d8..f509186c6 100644
> > --- a/lib/librte_vhost/vhost.c
> > +++ b/lib/librte_vhost/vhost.c
> > @@ -338,19 +338,22 @@ cleanup_device(struct virtio_net *dev, int
> > destroy)  }
> >
> >  static void
> > -vhost_free_async_mem(struct vhost_virtqueue *vq)
> > +vhost_free_async_mem(struct virtio_net *dev, struct vhost_virtqueue
> > +*vq)
> >  {
> > -	if (vq->async_pkts_info)
> > -		rte_free(vq->async_pkts_info);
> > -	if (vq->async_descs_split)
> > +	rte_free(vq->async_pkts_info);
> > +
> > +	if (vq_is_packed(dev)) {
> > +		rte_free(vq->async_buffers_packed);
> > +		vq->async_buffers_packed = NULL;
> > +	} else {
> 
> Doing this is not necessary:
> 
> 	rte_free(vq->async_buffers_packed);
> 	vq->async_buffers_packed = NULL;
> 	rte_free(vq->async_descs_split);
> 	vq->async_descs_split = NULL;
> 
> Above will just work and will avoid adding dev parameter.

async_buffers_packed and async_descs_split are two members of a union.
If I rte_free(vq->async_buffers_packed), then there is no need to rte_free(vq->async_descs_split).
So I use dev to determine which one I need to free.
Sure, I can free then both with no condition(I can also only free any one of them), but I think it's a little strange, Right?

> 
> 
> >  		rte_free(vq->async_descs_split);
> > -	if (vq->it_pool)
> > -		rte_free(vq->it_pool);
> > -	if (vq->vec_pool)
> > -		rte_free(vq->vec_pool);
> > +		vq->async_descs_split = NULL;
> > +	}
> > +
> > +	rte_free(vq->it_pool);
> > +	rte_free(vq->vec_pool);
> >
> >  	vq->async_pkts_info = NULL;
> > -	vq->async_descs_split = NULL;
> >  	vq->it_pool = NULL;
> >  	vq->vec_pool = NULL;
> >  }
> > @@ -360,10 +363,10 @@ free_vq(struct virtio_net *dev, struct
> > vhost_virtqueue *vq)  {
> >  	if (vq_is_packed(dev))
> >  		rte_free(vq->shadow_used_packed);
> > -	else {
> > +	else
> >  		rte_free(vq->shadow_used_split);
> > -		vhost_free_async_mem(vq);
> > -	}
> > +
> > +	vhost_free_async_mem(dev, vq);
> >  	rte_free(vq->batch_copy_elems);
> >  	if (vq->iotlb_pool)
> >  		rte_mempool_free(vq->iotlb_pool);
> > @@ -1626,10 +1629,9 @@ int rte_vhost_async_channel_register(int vid,
> uint16_t queue_id,
> >  	if (unlikely(vq == NULL || !dev->async_copy))
> >  		return -1;
> >
> > -	/* packed queue is not supported */
> > -	if (unlikely(vq_is_packed(dev) || !f.async_inorder)) {
> > +	if (unlikely(!f.async_inorder)) {
> >  		VHOST_LOG_CONFIG(ERR,
> > -			"async copy is not supported on packed queue or
> non-inorder mode "
> > +			"async copy is not supported on non-inorder mode "
> >  			"(vid %d, qid: %d)\n", vid, queue_id);
> >  		return -1;
> >  	}
> > @@ -1667,12 +1669,19 @@ int rte_vhost_async_channel_register(int vid,
> uint16_t queue_id,
> >  	vq->vec_pool = rte_malloc_socket(NULL,
> >  			VHOST_MAX_ASYNC_VEC * sizeof(struct iovec),
> >  			RTE_CACHE_LINE_SIZE, node);
> > -	vq->async_descs_split = rte_malloc_socket(NULL,
> > +	if (vq_is_packed(dev)) {
> > +		vq->async_buffers_packed = rte_malloc_socket(NULL,
> > +			vq->size * sizeof(struct vring_used_elem_packed),
> > +			RTE_CACHE_LINE_SIZE, node);
> > +	} else {
> > +		vq->async_descs_split = rte_malloc_socket(NULL,
> >  			vq->size * sizeof(struct vring_used_elem),
> >  			RTE_CACHE_LINE_SIZE, node);
> > -	if (!vq->async_descs_split || !vq->async_pkts_info ||
> > -		!vq->it_pool || !vq->vec_pool) {
> > -		vhost_free_async_mem(vq);
> > +	}
> > +
> > +	if (!vq->async_buffers_packed || !vq->async_descs_split ||
> > +		!vq->async_pkts_info || !vq->it_pool || !vq->vec_pool) {
> 
> Not really than of this error handling. Checking after every malloc if it suceed
> would be cleaner.

OK, make sense to me. But that means I need to add log(which can be more specific) after every check, do you thinks it's ok?
If you thinks it's ok, then I'll fix it in the next version.

> 
> > +		vhost_free_async_mem(dev, vq);
> >  		VHOST_LOG_CONFIG(ERR,
> >  				"async register failed: cannot allocate
> memory for vq data "
> >  				"(vid %d, qid: %d)\n", vid, queue_id); @@ -
> 1728,7 +1737,7 @@ int
> > rte_vhost_async_channel_unregister(int vid, uint16_t queue_id)
> >  		goto out;
> >  	}
> >
> > -	vhost_free_async_mem(vq);
> > +	vhost_free_async_mem(dev, vq);
> >
> >  	vq->async_ops.transfer_data = NULL;
> >  	vq->async_ops.check_completed_copies = NULL; diff --git
> > a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h index
> > f628714c2..673335217 100644
> > --- a/lib/librte_vhost/vhost.h
> > +++ b/lib/librte_vhost/vhost.h
> > @@ -201,9 +201,18 @@ struct vhost_virtqueue {
> >  	uint16_t	async_pkts_idx;
> >  	uint16_t	async_pkts_inflight_n;
> >  	uint16_t	async_last_pkts_n;
> > -	struct vring_used_elem  *async_descs_split;
> > -	uint16_t async_desc_idx;
> > -	uint16_t last_async_desc_idx;
> > +	union {
> > +		struct vring_used_elem  *async_descs_split;
> > +		struct vring_used_elem_packed *async_buffers_packed;
> > +	};
> > +	union {
> > +		uint16_t async_desc_idx;
> > +		uint16_t async_packed_buffer_idx;
> > +	};
> > +	union {
> > +		uint16_t last_async_desc_idx;
> > +		uint16_t last_async_buffer_idx;
> > +	};
> 
> Looks almost good to me now, thanks for doing the change.
> Only minor issue is the naming which is not consistent in the different fields.
> Sometimes it contains split or packed, sometimes not.

OK, I'll check these names, and fix them.

Thanks a lot.
Cheng

> 
> Maxime
  
Jiang, Cheng1 April 15, 2021, 5:54 a.m. UTC | #4
Hi Jiayu,

> -----Original Message-----
> From: Hu, Jiayu <jiayu.hu@intel.com>
> Sent: Thursday, April 15, 2021 10:03 AM
> To: Jiang, Cheng1 <cheng1.jiang@intel.com>; maxime.coquelin@redhat.com;
> Xia, Chenbo <chenbo.xia@intel.com>
> Cc: dev@dpdk.org; Yang, YvonneX <yvonnex.yang@intel.com>; Wang, Yinan
> <yinan.wang@intel.com>; Liu, Yong <yong.liu@intel.com>
> Subject: RE: [PATCH v7 2/4] vhost: add support for packed ring in async vhost
> 
> Hi Cheng,
> 
> > -----Original Message-----
> > From: Jiang, Cheng1 <cheng1.jiang@intel.com>
> > Sent: Wednesday, April 14, 2021 2:14 PM
> > To: maxime.coquelin@redhat.com; Xia, Chenbo <chenbo.xia@intel.com>
> > Cc: dev@dpdk.org; Hu, Jiayu <jiayu.hu@intel.com>; Yang, YvonneX
> > <yvonnex.yang@intel.com>; Wang, Yinan <yinan.wang@intel.com>; Liu,
> > Yong <yong.liu@intel.com>; Jiang, Cheng1 <cheng1.jiang@intel.com>
> > Subject: [PATCH v7 2/4] vhost: add support for packed ring in async
> > vhost
> >
> > For now async vhost data path only supports split ring. This patch
> > enables packed ring in async vhost data path to make async vhost
> > compatible with virtio 1.1 spec.
> >
> > Signed-off-by: Cheng Jiang <Cheng1.jiang@intel.com>
> > ---
> >  lib/librte_vhost/rte_vhost_async.h |   1 +
> >  lib/librte_vhost/vhost.c           |  49 ++--
> >  lib/librte_vhost/vhost.h           |  15 +-
> >  lib/librte_vhost/virtio_net.c      | 432 +++++++++++++++++++++++++++--
> >  4 files changed, 456 insertions(+), 41 deletions(-)
> >
> > diff --git a/lib/librte_vhost/rte_vhost_async.h
> > b/lib/librte_vhost/rte_vhost_async.h
> > index c855ff875..6faa31f5a 100644
> > --- a/lib/librte_vhost/rte_vhost_async.h
> > +++ b/lib/librte_vhost/rte_vhost_async.h
> > @@ -89,6 +89,7 @@ struct rte_vhost_async_channel_ops {  struct
> > async_inflight_info {  struct rte_mbuf *mbuf;  uint16_t descs; /* num
> > of descs inflight */
> > +uint16_t nr_buffers; /* num of buffers inflight for packed ring */
> >  };
> >
> >  /**
> > diff --git a/lib/librte_vhost/vhost.c b/lib/librte_vhost/vhost.c index
> > a70fe01d8..f509186c6 100644
> > --- a/lib/librte_vhost/vhost.c
> > +++ b/lib/librte_vhost/vhost.c
> > @@ -338,19 +338,22 @@ cleanup_device(struct virtio_net *dev, int
> > destroy)  }
> >
> >  static void
> > -vhost_free_async_mem(struct vhost_virtqueue *vq)
> > +vhost_free_async_mem(struct virtio_net *dev, struct vhost_virtqueue
> > +*vq)
> >  {
> > -if (vq->async_pkts_info)
> > -rte_free(vq->async_pkts_info);
> > -if (vq->async_descs_split)
> > +rte_free(vq->async_pkts_info);
> > +
> > +if (vq_is_packed(dev)) {
> > +rte_free(vq->async_buffers_packed);
> > +vq->async_buffers_packed = NULL;
> > +} else {
> >  rte_free(vq->async_descs_split);
> > -if (vq->it_pool)
> > -rte_free(vq->it_pool);
> > -if (vq->vec_pool)
> > -rte_free(vq->vec_pool);
> > +vq->async_descs_split = NULL;
> > +}
> > +
> > +rte_free(vq->it_pool);
> > +rte_free(vq->vec_pool);
> >
> >  vq->async_pkts_info = NULL;
> > -vq->async_descs_split = NULL;
> >  vq->it_pool = NULL;
> >  vq->vec_pool = NULL;
> >  }
> > @@ -360,10 +363,10 @@ free_vq(struct virtio_net *dev, struct
> > vhost_virtqueue *vq)  {  if (vq_is_packed(dev))
> > rte_free(vq->shadow_used_packed); -else {
> > +else
> >  rte_free(vq->shadow_used_split);
> > -vhost_free_async_mem(vq);
> > -}
> > +
> > +vhost_free_async_mem(dev, vq);
> >  rte_free(vq->batch_copy_elems);
> >  if (vq->iotlb_pool)
> >  rte_mempool_free(vq->iotlb_pool);
> > @@ -1626,10 +1629,9 @@ int rte_vhost_async_channel_register(int vid,
> > uint16_t queue_id,  if (unlikely(vq == NULL || !dev->async_copy))
> > return -1;
> >
> > -/* packed queue is not supported */
> > -if (unlikely(vq_is_packed(dev) || !f.async_inorder)) {
> > +if (unlikely(!f.async_inorder)) {
> >  VHOST_LOG_CONFIG(ERR,
> > -"async copy is not supported on packed queue or non-inorder mode "
> > +"async copy is not supported on non-inorder mode "
> >  "(vid %d, qid: %d)\n", vid, queue_id);  return -1;  } @@ -1667,12
> > +1669,19 @@ int rte_vhost_async_channel_register(int vid, uint16_t
> > queue_id,  vq->vec_pool = rte_malloc_socket(NULL,
> VHOST_MAX_ASYNC_VEC
> > * sizeof(struct iovec),  RTE_CACHE_LINE_SIZE, node);
> > -vq->async_descs_split = rte_malloc_socket(NULL,
> > +if (vq_is_packed(dev)) {
> > +vq->async_buffers_packed = rte_malloc_socket(NULL, size *
> > +vq->sizeof(struct vring_used_elem_packed),
> > +RTE_CACHE_LINE_SIZE, node);
> > +} else {
> > +vq->async_descs_split = rte_malloc_socket(NULL,
> >  vq->size * sizeof(struct vring_used_elem),  RTE_CACHE_LINE_SIZE,
> > node); -if (!vq->async_descs_split || !vq->async_pkts_info ||
> > -!vq->it_pool || !vq->vec_pool) { -vhost_free_async_mem(vq);
> > +}
> > +
> > +if (!vq->async_buffers_packed || !vq->async_descs_split ||
> async_buffers_packed and async_descs_split are two members of a union.
> Like the way processed in vhost_free_async_mem(), do you think it's better
> to check if they are NULL in if-else respectively?

Sure, make sense to me. I'll fix them together with other async mem check.

> 
> > +!vq->async_pkts_info || !vq->it_pool || !vq->vec_pool) {
> > +vhost_free_async_mem(dev, vq);
> >  VHOST_LOG_CONFIG(ERR,
> >  "async register failed: cannot allocate memory for vq data "
> >  "(vid %d, qid: %d)\n", vid, queue_id); @@ -1728,7 +1737,7 @@ int
> > rte_vhost_async_channel_unregister(int vid, uint16_t queue_id)  goto
> > out;  }
> >
> > -vhost_free_async_mem(vq);
> > +vhost_free_async_mem(dev, vq);
> >
> >  vq->async_ops.transfer_data = NULL;
> >  vq->async_ops.check_completed_copies = NULL; diff --git
> > a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h index
> > f628714c2..673335217 100644
> > --- a/lib/librte_vhost/vhost.h
> > +++ b/lib/librte_vhost/vhost.h
> > @@ -201,9 +201,18 @@ struct vhost_virtqueue {  uint16_tasync_pkts_idx;
> > uint16_tasync_pkts_inflight_n;  uint16_tasync_last_pkts_n; -struct
> > vring_used_elem  *async_descs_split; -uint16_t async_desc_idx;
> > -uint16_t last_async_desc_idx;
> > +union {
> > +struct vring_used_elem  *async_descs_split; struct
> > +vring_used_elem_packed *async_buffers_packed; }; union { uint16_t
> > +async_desc_idx; uint16_t async_packed_buffer_idx; }; union { uint16_t
> > +last_async_desc_idx; uint16_t last_async_buffer_idx; };
> >
> >  /* vq async features */
> >  boolasync_inorder;
> > diff --git a/lib/librte_vhost/virtio_net.c
> > b/lib/librte_vhost/virtio_net.c index 438bdafd1..54e11e3a5 100644
> > --- a/lib/librte_vhost/virtio_net.c
> > +++ b/lib/librte_vhost/virtio_net.c
> > @@ -363,14 +363,14 @@
> > vhost_shadow_dequeue_single_packed_inorder(struct vhost_virtqueue
> *vq,
> > }
> >
> >  static __rte_always_inline void
> > -vhost_shadow_enqueue_single_packed(struct virtio_net *dev,
> > -   struct vhost_virtqueue *vq,
> > -   uint32_t len[],
> > -   uint16_t id[],
> > -   uint16_t count[],
> > +vhost_shadow_enqueue_packed(struct vhost_virtqueue *vq,
> > +   uint32_t *len,
> > +   uint16_t *id,
> > +   uint16_t *count,
> >     uint16_t num_buffers)
> >  {
> >  uint16_t i;
> > +
> >  for (i = 0; i < num_buffers; i++) {
> >  /* enqueue shadow flush action aligned with batch num */  if
> > (!vq->shadow_used_idx) @@ -382,6 +382,17 @@
> > vhost_shadow_enqueue_single_packed(struct
> > virtio_net *dev,
> >  vq->shadow_aligned_idx += count[i];
> >  vq->shadow_used_idx++;
> >  }
> > +}
> > +
> > +static __rte_always_inline void
> > +vhost_shadow_enqueue_single_packed(struct virtio_net *dev,
> > +   struct vhost_virtqueue *vq,
> > +   uint32_t *len,
> > +   uint16_t *id,
> > +   uint16_t *count,
> > +   uint16_t num_buffers)
> > +{
> > +vhost_shadow_enqueue_packed(vq, len, id, count, num_buffers);
> >
> >  if (vq->shadow_aligned_idx >= PACKED_BATCH_SIZE) {
> > do_data_copy_enqueue(dev, vq); @@ -1474,6 +1485,23 @@
> > store_dma_desc_info_split(struct vring_used_elem *s_ring, struct
> > vring_used_elem  }  }
> >
> > +static __rte_always_inline void
> > +store_dma_desc_info_packed(struct vring_used_elem_packed *s_ring,
> > +struct vring_used_elem_packed *d_ring, uint16_t ring_size, uint16_t
> > +s_idx, uint16_t d_idx, uint16_t
> > count)
> > +{
> > +uint16_t elem_size = sizeof(struct vring_used_elem_packed);
> > +
> > +if (d_idx + count <= ring_size) {
> > +rte_memcpy(d_ring + d_idx, s_ring + s_idx, count *
> > elem_size);
> > +} else {
> > +uint16_t size = ring_size - d_idx;
> > +
> > +rte_memcpy(d_ring + d_idx, s_ring + s_idx, size * elem_size);
> > +rte_memcpy(d_ring, s_ring + s_idx + size, (count - size) *
> > elem_size);
> > +}
> > +}
> > +
> >  static __rte_noinline uint32_t
> >  virtio_dev_rx_async_submit_split(struct virtio_net *dev,  struct
> > vhost_virtqueue *vq, uint16_t queue_id, @@ -1641,6 +1669,330 @@
> > virtio_dev_rx_async_submit_split(struct
> > virtio_net *dev,
> >  return pkt_idx;
> >  }
> >
> > +static __rte_always_inline void
> > +vhost_update_used_packed(struct vhost_virtqueue *vq, struct
> > +vring_used_elem_packed *shadow_ring, uint16_t count) { int i;
> > +uint16_t used_idx = vq->last_used_idx; uint16_t head_idx =
> > +vq->last_used_idx; uint16_t head_flags = 0;
> > +
> > +if (count == 0)
> > +return;
> > +
> > +/* Split loop in two to save memory barriers */ for (i = 0; i <
> > +count; i++) {
> > +vq->desc_packed[used_idx].id = shadow_ring[i].id;
> > +vq->desc_packed[used_idx].len = shadow_ring[i].len;
> > +
> > +used_idx += shadow_ring[i].count;
> > +if (used_idx >= vq->size)
> > +used_idx -= vq->size;
> > +}
> > +
> > +/* The ordering for storing desc flags needs to be enforced. */
> > +rte_atomic_thread_fence(__ATOMIC_RELEASE);
> > +
> > +for (i = 0; i < count; i++) {
> > +uint16_t flags;
> > +
> > +if (vq->shadow_used_packed[i].len)
> > +flags = VRING_DESC_F_WRITE;
> > +else
> > +flags = 0;
> > +
> > +if (vq->used_wrap_counter) {
> > +flags |= VRING_DESC_F_USED;
> > +flags |= VRING_DESC_F_AVAIL;
> > +} else {
> > +flags &= ~VRING_DESC_F_USED;
> > +flags &= ~VRING_DESC_F_AVAIL;
> > +}
> > +
> > +if (i > 0) {
> > +vq->desc_packed[vq->last_used_idx].flags = flags;
> > +
> No need a blank line above.

Sure, thanks.

> 
> > +} else {
> > +head_idx = vq->last_used_idx;
> > +head_flags = flags;
> > +}
> > +
> > +vq_inc_last_used_packed(vq, shadow_ring[i].count); }
> > +
> > +vq->desc_packed[head_idx].flags = head_flags;
> > +}
> > +
> > +static __rte_always_inline int
> > +vhost_enqueue_async_single_packed(struct virtio_net *dev,
> > +    struct vhost_virtqueue *vq,
> > +    struct rte_mbuf *pkt,
> > +    struct buf_vector *buf_vec,
> > +    uint16_t *nr_descs,
> > +    uint16_t *nr_buffers,
> > +    struct vring_packed_desc *async_descs,
> > +    struct iovec *src_iovec, struct iovec *dst_iovec,
> > +    struct rte_vhost_iov_iter *src_it,
> > +    struct rte_vhost_iov_iter *dst_it) { uint16_t nr_vec = 0;
> > +uint16_t avail_idx = vq->last_avail_idx; uint16_t max_tries, tries =
> > +0; uint16_t buf_id = 0; uint32_t len = 0; uint16_t desc_count = 0;
> > +uint32_t size = pkt->pkt_len + sizeof(struct
> > virtio_net_hdr_mrg_rxbuf);
> > +uint32_t buffer_len[vq->size];
> > +uint16_t buffer_buf_id[vq->size];
> > +uint16_t buffer_desc_count[vq->size]; *nr_buffers = 0;
> > +
> > +if (rxvq_is_mergeable(dev))
> > +max_tries = vq->size - 1;
> > +else
> > +max_tries = 1;
> > +
> > +while (size > 0) {
> > +/*
> > + * if we tried all available ring items, and still
> > + * can't get enough buf, it means something abnormal
> > + * happened.
> > + */
> > +if (unlikely(++tries > max_tries))
> > +return -1;
> > +
> > +if (unlikely(fill_vec_buf_packed(dev, vq, avail_idx,
> > &desc_count, buf_vec, &nr_vec,
> > +&buf_id, &len,
> > VHOST_ACCESS_RW) < 0))
> > +return -1;
> > +
> > +len = RTE_MIN(len, size);
> > +size -= len;
> > +
> > +buffer_len[*nr_buffers] = len;
> > +buffer_buf_id[*nr_buffers] = buf_id;
> > +buffer_desc_count[*nr_buffers] = desc_count; *nr_buffers += 1;
> > +
> > +*nr_descs += desc_count;
> > +avail_idx += desc_count;
> > +if (avail_idx >= vq->size)
> > +avail_idx -= vq->size;
> > +}
> > +
> > +if (async_mbuf_to_desc(dev, vq, pkt, buf_vec, nr_vec, *nr_buffers,
> > src_iovec, dst_iovec,
> > +src_it, dst_it) < 0)
> > +return -1;
> > +/* store descriptors for DMA */
> > +if (avail_idx >= *nr_descs) {
> > +rte_memcpy(async_descs, &vq->desc_packed[vq-
> > >last_avail_idx],
> > +*nr_descs * sizeof(struct vring_packed_desc)); } else { uint16_t
> > +nr_copy = vq->size - vq->last_avail_idx; rte_memcpy(async_descs,
> > +&vq->desc_packed[vq-
> > >last_avail_idx],
> > +nr_copy * sizeof(struct vring_packed_desc)); rte_memcpy(async_descs +
> > +nr_copy, vq->desc_packed, (*nr_descs - nr_copy) * sizeof(struct
> > vring_packed_desc));
> > +}
> > +
> > +vhost_shadow_enqueue_packed(vq, buffer_len, buffer_buf_id,
> > buffer_desc_count, *nr_buffers);
> > +
> > +return 0;
> > +}
> > +
> > +static __rte_always_inline int16_t
> > +virtio_dev_rx_async_single_packed(struct virtio_net *dev, struct
> > vhost_virtqueue *vq,
> > +    struct rte_mbuf *pkt, uint16_t *nr_descs, uint16_t
> > *nr_buffers,
> > +    struct vring_packed_desc *async_descs,
> > +    struct iovec *src_iovec, struct iovec *dst_iovec,
> > +    struct rte_vhost_iov_iter *src_it, struct
> > rte_vhost_iov_iter *dst_it)
> > +{
> > +struct buf_vector buf_vec[BUF_VECTOR_MAX]; *nr_descs = 0;
> *nr_buffers
> > += 0;
> > +
> > +if (unlikely(vhost_enqueue_async_single_packed(dev, vq, pkt,
> > buf_vec, nr_descs, nr_buffers,
> > + async_descs, src_iovec,
> > dst_iovec,
> > + src_it, dst_it) < 0)) {
> > +VHOST_LOG_DATA(DEBUG, "(%d) failed to get enough desc
> > from vring\n", dev->vid);
> > +return -1;
> > +}
> > +
> > +VHOST_LOG_DATA(DEBUG, "(%d) current index %d | end
> > index %d\n",
> > +dev->vid, vq->last_avail_idx, vq->last_avail_idx +
> > *nr_descs);
> > +
> > +return 0;
> > +}
> > +
> > +static __rte_always_inline void
> > +dma_error_handler_packed(struct vhost_virtqueue *vq, struct
> > vring_packed_desc *async_descs,
> > +uint16_t async_descs_idx, uint16_t slot_idx, uint32_t
> > nr_err,
> > +uint32_t *pkt_idx, uint32_t *num_async_pkts,
> > uint32_t *num_done_pkts)
> > +{
> > +uint16_t descs_err = 0;
> > +uint16_t buffers_err = 0;
> > +struct async_inflight_info *pkts_info = vq->async_pkts_info;
> > +
> > +*num_async_pkts -= nr_err;
> > +*pkt_idx -= nr_err;
> > +/* calculate the sum of buffers and descs of DMA-error packets. */
> > +while (nr_err-- > 0) { descs_err += pkts_info[slot_idx %
> > +vq->size].descs;
> I notice there are several parts using "%" to wrap around index, but existed
> code uses "& (vq->size - 1)" instead. I think it's better to keep it consistent.

Unlike split ring, packed ring size is not necessarily a power of 2. So I can't use "& (vq->size - 1) in packed ring.

Thanks,
Cheng

> 
> Thanks,
> Jiayu
  

Patch

diff --git a/lib/librte_vhost/rte_vhost_async.h b/lib/librte_vhost/rte_vhost_async.h
index c855ff875..6faa31f5a 100644
--- a/lib/librte_vhost/rte_vhost_async.h
+++ b/lib/librte_vhost/rte_vhost_async.h
@@ -89,6 +89,7 @@  struct rte_vhost_async_channel_ops {
 struct async_inflight_info {
 	struct rte_mbuf *mbuf;
 	uint16_t descs; /* num of descs inflight */
+	uint16_t nr_buffers; /* num of buffers inflight for packed ring */
 };
 
 /**
diff --git a/lib/librte_vhost/vhost.c b/lib/librte_vhost/vhost.c
index a70fe01d8..f509186c6 100644
--- a/lib/librte_vhost/vhost.c
+++ b/lib/librte_vhost/vhost.c
@@ -338,19 +338,22 @@  cleanup_device(struct virtio_net *dev, int destroy)
 }
 
 static void
-vhost_free_async_mem(struct vhost_virtqueue *vq)
+vhost_free_async_mem(struct virtio_net *dev, struct vhost_virtqueue *vq)
 {
-	if (vq->async_pkts_info)
-		rte_free(vq->async_pkts_info);
-	if (vq->async_descs_split)
+	rte_free(vq->async_pkts_info);
+
+	if (vq_is_packed(dev)) {
+		rte_free(vq->async_buffers_packed);
+		vq->async_buffers_packed = NULL;
+	} else {
 		rte_free(vq->async_descs_split);
-	if (vq->it_pool)
-		rte_free(vq->it_pool);
-	if (vq->vec_pool)
-		rte_free(vq->vec_pool);
+		vq->async_descs_split = NULL;
+	}
+
+	rte_free(vq->it_pool);
+	rte_free(vq->vec_pool);
 
 	vq->async_pkts_info = NULL;
-	vq->async_descs_split = NULL;
 	vq->it_pool = NULL;
 	vq->vec_pool = NULL;
 }
@@ -360,10 +363,10 @@  free_vq(struct virtio_net *dev, struct vhost_virtqueue *vq)
 {
 	if (vq_is_packed(dev))
 		rte_free(vq->shadow_used_packed);
-	else {
+	else
 		rte_free(vq->shadow_used_split);
-		vhost_free_async_mem(vq);
-	}
+
+	vhost_free_async_mem(dev, vq);
 	rte_free(vq->batch_copy_elems);
 	if (vq->iotlb_pool)
 		rte_mempool_free(vq->iotlb_pool);
@@ -1626,10 +1629,9 @@  int rte_vhost_async_channel_register(int vid, uint16_t queue_id,
 	if (unlikely(vq == NULL || !dev->async_copy))
 		return -1;
 
-	/* packed queue is not supported */
-	if (unlikely(vq_is_packed(dev) || !f.async_inorder)) {
+	if (unlikely(!f.async_inorder)) {
 		VHOST_LOG_CONFIG(ERR,
-			"async copy is not supported on packed queue or non-inorder mode "
+			"async copy is not supported on non-inorder mode "
 			"(vid %d, qid: %d)\n", vid, queue_id);
 		return -1;
 	}
@@ -1667,12 +1669,19 @@  int rte_vhost_async_channel_register(int vid, uint16_t queue_id,
 	vq->vec_pool = rte_malloc_socket(NULL,
 			VHOST_MAX_ASYNC_VEC * sizeof(struct iovec),
 			RTE_CACHE_LINE_SIZE, node);
-	vq->async_descs_split = rte_malloc_socket(NULL,
+	if (vq_is_packed(dev)) {
+		vq->async_buffers_packed = rte_malloc_socket(NULL,
+			vq->size * sizeof(struct vring_used_elem_packed),
+			RTE_CACHE_LINE_SIZE, node);
+	} else {
+		vq->async_descs_split = rte_malloc_socket(NULL,
 			vq->size * sizeof(struct vring_used_elem),
 			RTE_CACHE_LINE_SIZE, node);
-	if (!vq->async_descs_split || !vq->async_pkts_info ||
-		!vq->it_pool || !vq->vec_pool) {
-		vhost_free_async_mem(vq);
+	}
+
+	if (!vq->async_buffers_packed || !vq->async_descs_split ||
+		!vq->async_pkts_info || !vq->it_pool || !vq->vec_pool) {
+		vhost_free_async_mem(dev, vq);
 		VHOST_LOG_CONFIG(ERR,
 				"async register failed: cannot allocate memory for vq data "
 				"(vid %d, qid: %d)\n", vid, queue_id);
@@ -1728,7 +1737,7 @@  int rte_vhost_async_channel_unregister(int vid, uint16_t queue_id)
 		goto out;
 	}
 
-	vhost_free_async_mem(vq);
+	vhost_free_async_mem(dev, vq);
 
 	vq->async_ops.transfer_data = NULL;
 	vq->async_ops.check_completed_copies = NULL;
diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h
index f628714c2..673335217 100644
--- a/lib/librte_vhost/vhost.h
+++ b/lib/librte_vhost/vhost.h
@@ -201,9 +201,18 @@  struct vhost_virtqueue {
 	uint16_t	async_pkts_idx;
 	uint16_t	async_pkts_inflight_n;
 	uint16_t	async_last_pkts_n;
-	struct vring_used_elem  *async_descs_split;
-	uint16_t async_desc_idx;
-	uint16_t last_async_desc_idx;
+	union {
+		struct vring_used_elem  *async_descs_split;
+		struct vring_used_elem_packed *async_buffers_packed;
+	};
+	union {
+		uint16_t async_desc_idx;
+		uint16_t async_packed_buffer_idx;
+	};
+	union {
+		uint16_t last_async_desc_idx;
+		uint16_t last_async_buffer_idx;
+	};
 
 	/* vq async features */
 	bool		async_inorder;
diff --git a/lib/librte_vhost/virtio_net.c b/lib/librte_vhost/virtio_net.c
index 438bdafd1..54e11e3a5 100644
--- a/lib/librte_vhost/virtio_net.c
+++ b/lib/librte_vhost/virtio_net.c
@@ -363,14 +363,14 @@  vhost_shadow_dequeue_single_packed_inorder(struct vhost_virtqueue *vq,
 }
 
 static __rte_always_inline void
-vhost_shadow_enqueue_single_packed(struct virtio_net *dev,
-				   struct vhost_virtqueue *vq,
-				   uint32_t len[],
-				   uint16_t id[],
-				   uint16_t count[],
+vhost_shadow_enqueue_packed(struct vhost_virtqueue *vq,
+				   uint32_t *len,
+				   uint16_t *id,
+				   uint16_t *count,
 				   uint16_t num_buffers)
 {
 	uint16_t i;
+
 	for (i = 0; i < num_buffers; i++) {
 		/* enqueue shadow flush action aligned with batch num */
 		if (!vq->shadow_used_idx)
@@ -382,6 +382,17 @@  vhost_shadow_enqueue_single_packed(struct virtio_net *dev,
 		vq->shadow_aligned_idx += count[i];
 		vq->shadow_used_idx++;
 	}
+}
+
+static __rte_always_inline void
+vhost_shadow_enqueue_single_packed(struct virtio_net *dev,
+				   struct vhost_virtqueue *vq,
+				   uint32_t *len,
+				   uint16_t *id,
+				   uint16_t *count,
+				   uint16_t num_buffers)
+{
+	vhost_shadow_enqueue_packed(vq, len, id, count, num_buffers);
 
 	if (vq->shadow_aligned_idx >= PACKED_BATCH_SIZE) {
 		do_data_copy_enqueue(dev, vq);
@@ -1474,6 +1485,23 @@  store_dma_desc_info_split(struct vring_used_elem *s_ring, struct vring_used_elem
 	}
 }
 
+static __rte_always_inline void
+store_dma_desc_info_packed(struct vring_used_elem_packed *s_ring,
+		struct vring_used_elem_packed *d_ring,
+		uint16_t ring_size, uint16_t s_idx, uint16_t d_idx, uint16_t count)
+{
+	uint16_t elem_size = sizeof(struct vring_used_elem_packed);
+
+	if (d_idx + count <= ring_size) {
+		rte_memcpy(d_ring + d_idx, s_ring + s_idx, count * elem_size);
+	} else {
+		uint16_t size = ring_size - d_idx;
+
+		rte_memcpy(d_ring + d_idx, s_ring + s_idx, size * elem_size);
+		rte_memcpy(d_ring, s_ring + s_idx + size, (count - size) * elem_size);
+	}
+}
+
 static __rte_noinline uint32_t
 virtio_dev_rx_async_submit_split(struct virtio_net *dev,
 	struct vhost_virtqueue *vq, uint16_t queue_id,
@@ -1641,6 +1669,330 @@  virtio_dev_rx_async_submit_split(struct virtio_net *dev,
 	return pkt_idx;
 }
 
+static __rte_always_inline void
+vhost_update_used_packed(struct vhost_virtqueue *vq,
+			struct vring_used_elem_packed *shadow_ring,
+			uint16_t count)
+{
+	int i;
+	uint16_t used_idx = vq->last_used_idx;
+	uint16_t head_idx = vq->last_used_idx;
+	uint16_t head_flags = 0;
+
+	if (count == 0)
+		return;
+
+	/* Split loop in two to save memory barriers */
+	for (i = 0; i < count; i++) {
+		vq->desc_packed[used_idx].id = shadow_ring[i].id;
+		vq->desc_packed[used_idx].len = shadow_ring[i].len;
+
+		used_idx += shadow_ring[i].count;
+		if (used_idx >= vq->size)
+			used_idx -= vq->size;
+	}
+
+	/* The ordering for storing desc flags needs to be enforced. */
+	rte_atomic_thread_fence(__ATOMIC_RELEASE);
+
+	for (i = 0; i < count; i++) {
+		uint16_t flags;
+
+		if (vq->shadow_used_packed[i].len)
+			flags = VRING_DESC_F_WRITE;
+		else
+			flags = 0;
+
+		if (vq->used_wrap_counter) {
+			flags |= VRING_DESC_F_USED;
+			flags |= VRING_DESC_F_AVAIL;
+		} else {
+			flags &= ~VRING_DESC_F_USED;
+			flags &= ~VRING_DESC_F_AVAIL;
+		}
+
+		if (i > 0) {
+			vq->desc_packed[vq->last_used_idx].flags = flags;
+
+		} else {
+			head_idx = vq->last_used_idx;
+			head_flags = flags;
+		}
+
+		vq_inc_last_used_packed(vq, shadow_ring[i].count);
+	}
+
+	vq->desc_packed[head_idx].flags = head_flags;
+}
+
+static __rte_always_inline int
+vhost_enqueue_async_single_packed(struct virtio_net *dev,
+			    struct vhost_virtqueue *vq,
+			    struct rte_mbuf *pkt,
+			    struct buf_vector *buf_vec,
+			    uint16_t *nr_descs,
+			    uint16_t *nr_buffers,
+			    struct vring_packed_desc *async_descs,
+			    struct iovec *src_iovec, struct iovec *dst_iovec,
+			    struct rte_vhost_iov_iter *src_it,
+			    struct rte_vhost_iov_iter *dst_it)
+{
+	uint16_t nr_vec = 0;
+	uint16_t avail_idx = vq->last_avail_idx;
+	uint16_t max_tries, tries = 0;
+	uint16_t buf_id = 0;
+	uint32_t len = 0;
+	uint16_t desc_count = 0;
+	uint32_t size = pkt->pkt_len + sizeof(struct virtio_net_hdr_mrg_rxbuf);
+	uint32_t buffer_len[vq->size];
+	uint16_t buffer_buf_id[vq->size];
+	uint16_t buffer_desc_count[vq->size];
+	*nr_buffers = 0;
+
+	if (rxvq_is_mergeable(dev))
+		max_tries = vq->size - 1;
+	else
+		max_tries = 1;
+
+	while (size > 0) {
+		/*
+		 * if we tried all available ring items, and still
+		 * can't get enough buf, it means something abnormal
+		 * happened.
+		 */
+		if (unlikely(++tries > max_tries))
+			return -1;
+
+		if (unlikely(fill_vec_buf_packed(dev, vq, avail_idx, &desc_count, buf_vec, &nr_vec,
+						&buf_id, &len, VHOST_ACCESS_RW) < 0))
+			return -1;
+
+		len = RTE_MIN(len, size);
+		size -= len;
+
+		buffer_len[*nr_buffers] = len;
+		buffer_buf_id[*nr_buffers] = buf_id;
+		buffer_desc_count[*nr_buffers] = desc_count;
+		*nr_buffers += 1;
+
+		*nr_descs += desc_count;
+		avail_idx += desc_count;
+		if (avail_idx >= vq->size)
+			avail_idx -= vq->size;
+	}
+
+	if (async_mbuf_to_desc(dev, vq, pkt, buf_vec, nr_vec, *nr_buffers, src_iovec, dst_iovec,
+			src_it, dst_it) < 0)
+		return -1;
+	/* store descriptors for DMA */
+	if (avail_idx >= *nr_descs) {
+		rte_memcpy(async_descs, &vq->desc_packed[vq->last_avail_idx],
+			*nr_descs * sizeof(struct vring_packed_desc));
+	} else {
+		uint16_t nr_copy = vq->size - vq->last_avail_idx;
+		rte_memcpy(async_descs, &vq->desc_packed[vq->last_avail_idx],
+			nr_copy * sizeof(struct vring_packed_desc));
+		rte_memcpy(async_descs + nr_copy, vq->desc_packed,
+			(*nr_descs - nr_copy) * sizeof(struct vring_packed_desc));
+	}
+
+	vhost_shadow_enqueue_packed(vq, buffer_len, buffer_buf_id, buffer_desc_count, *nr_buffers);
+
+	return 0;
+}
+
+static __rte_always_inline int16_t
+virtio_dev_rx_async_single_packed(struct virtio_net *dev, struct vhost_virtqueue *vq,
+			    struct rte_mbuf *pkt, uint16_t *nr_descs, uint16_t *nr_buffers,
+			    struct vring_packed_desc *async_descs,
+			    struct iovec *src_iovec, struct iovec *dst_iovec,
+			    struct rte_vhost_iov_iter *src_it, struct rte_vhost_iov_iter *dst_it)
+{
+	struct buf_vector buf_vec[BUF_VECTOR_MAX];
+	*nr_descs = 0;
+	*nr_buffers = 0;
+
+	if (unlikely(vhost_enqueue_async_single_packed(dev, vq, pkt, buf_vec, nr_descs, nr_buffers,
+						 async_descs, src_iovec, dst_iovec,
+						 src_it, dst_it) < 0)) {
+		VHOST_LOG_DATA(DEBUG, "(%d) failed to get enough desc from vring\n", dev->vid);
+		return -1;
+	}
+
+	VHOST_LOG_DATA(DEBUG, "(%d) current index %d | end index %d\n",
+			dev->vid, vq->last_avail_idx, vq->last_avail_idx + *nr_descs);
+
+	return 0;
+}
+
+static __rte_always_inline void
+dma_error_handler_packed(struct vhost_virtqueue *vq, struct vring_packed_desc *async_descs,
+			uint16_t async_descs_idx, uint16_t slot_idx, uint32_t nr_err,
+			uint32_t *pkt_idx, uint32_t *num_async_pkts, uint32_t *num_done_pkts)
+{
+	uint16_t descs_err = 0;
+	uint16_t buffers_err = 0;
+	struct async_inflight_info *pkts_info = vq->async_pkts_info;
+
+	*num_async_pkts -= nr_err;
+	*pkt_idx -= nr_err;
+	/* calculate the sum of buffers and descs of DMA-error packets. */
+	while (nr_err-- > 0) {
+		descs_err += pkts_info[slot_idx % vq->size].descs;
+		buffers_err += pkts_info[slot_idx % vq->size].nr_buffers;
+		slot_idx--;
+	}
+
+	vq->async_packed_buffer_idx -= buffers_err;
+
+	if (vq->last_avail_idx >= descs_err) {
+		vq->last_avail_idx -= descs_err;
+
+		rte_memcpy(&vq->desc_packed[vq->last_avail_idx],
+			&async_descs[async_descs_idx - descs_err],
+			descs_err * sizeof(struct vring_packed_desc));
+	} else {
+		uint16_t nr_copy;
+
+		vq->last_avail_idx = vq->last_avail_idx + vq->size - descs_err;
+		nr_copy = vq->size - vq->last_avail_idx;
+		rte_memcpy(&vq->desc_packed[vq->last_avail_idx],
+			&async_descs[async_descs_idx - descs_err],
+			nr_copy * sizeof(struct vring_packed_desc));
+		descs_err -= nr_copy;
+		rte_memcpy(&vq->desc_packed[0], &async_descs[async_descs_idx - descs_err],
+			descs_err * sizeof(struct vring_packed_desc));
+		vq->avail_wrap_counter ^= 1;
+	}
+
+	*num_done_pkts = *pkt_idx - *num_async_pkts;
+}
+
+static __rte_noinline uint32_t
+virtio_dev_rx_async_submit_packed(struct virtio_net *dev,
+	struct vhost_virtqueue *vq, uint16_t queue_id,
+	struct rte_mbuf **pkts, uint32_t count,
+	struct rte_mbuf **comp_pkts, uint32_t *comp_count)
+{
+	uint32_t pkt_idx = 0, pkt_burst_idx = 0;
+	uint16_t async_descs_idx = 0;
+	uint16_t num_buffers;
+	uint16_t num_desc;
+
+	struct rte_vhost_iov_iter *it_pool = vq->it_pool;
+	struct iovec *vec_pool = vq->vec_pool;
+	struct rte_vhost_async_desc tdes[MAX_PKT_BURST];
+	struct iovec *src_iovec = vec_pool;
+	struct iovec *dst_iovec = vec_pool + (VHOST_MAX_ASYNC_VEC >> 1);
+	uint16_t slot_idx = 0;
+	uint16_t segs_await = 0;
+	uint16_t iovec_idx = 0, it_idx = 0;
+	struct async_inflight_info *pkts_info = vq->async_pkts_info;
+	uint32_t n_pkts = 0, pkt_err = 0;
+	uint32_t num_async_pkts = 0, num_done_pkts = 0;
+	struct vring_packed_desc async_descs[vq->size];
+
+	rte_prefetch0(&vq->desc_packed[vq->last_avail_idx]);
+
+	for (pkt_idx = 0; pkt_idx < count; pkt_idx++) {
+		if (unlikely(virtio_dev_rx_async_single_packed(dev, vq, pkts[pkt_idx],
+						&num_desc, &num_buffers,
+						&async_descs[async_descs_idx],
+						&src_iovec[iovec_idx], &dst_iovec[iovec_idx],
+						&it_pool[it_idx], &it_pool[it_idx + 1]) < 0))
+			break;
+
+		VHOST_LOG_DATA(DEBUG, "(%d) current index %d | end index %d\n",
+			dev->vid, vq->last_avail_idx,
+			vq->last_avail_idx + num_desc);
+
+		slot_idx = (vq->async_pkts_idx + num_async_pkts) % vq->size;
+		if (it_pool[it_idx].count) {
+			uint16_t from, to;
+
+			async_descs_idx += num_desc;
+			async_fill_desc(&tdes[pkt_burst_idx++],
+				&it_pool[it_idx], &it_pool[it_idx + 1]);
+			pkts_info[slot_idx].descs = num_desc;
+			pkts_info[slot_idx].nr_buffers = num_buffers;
+			pkts_info[slot_idx].mbuf = pkts[pkt_idx];
+			num_async_pkts++;
+			iovec_idx += it_pool[it_idx].nr_segs;
+			it_idx += 2;
+
+			segs_await += it_pool[it_idx].nr_segs;
+
+			/**
+			 * recover shadow used ring and keep DMA-occupied
+			 * descriptors.
+			 */
+			from = vq->shadow_used_idx - num_buffers;
+			to = vq->async_packed_buffer_idx % vq->size;
+			store_dma_desc_info_packed(vq->shadow_used_packed,
+					vq->async_buffers_packed, vq->size, from, to, num_buffers);
+
+			vq->async_packed_buffer_idx += num_buffers;
+			vq->shadow_used_idx -= num_buffers;
+		} else {
+			comp_pkts[num_done_pkts++] = pkts[pkt_idx];
+		}
+
+		vq_inc_last_avail_packed(vq, num_desc);
+
+		/*
+		 * conditions to trigger async device transfer:
+		 * - buffered packet number reaches transfer threshold
+		 * - unused async iov number is less than max vhost vector
+		 */
+		if (unlikely(pkt_burst_idx >= VHOST_ASYNC_BATCH_THRESHOLD ||
+			((VHOST_MAX_ASYNC_VEC >> 1) - segs_await < BUF_VECTOR_MAX))) {
+			n_pkts = vq->async_ops.transfer_data(dev->vid, queue_id,
+				tdes, 0, pkt_burst_idx);
+			iovec_idx = 0;
+			it_idx = 0;
+			segs_await = 0;
+			vq->async_pkts_inflight_n += n_pkts;
+
+			if (unlikely(n_pkts < pkt_burst_idx)) {
+				/*
+				 * log error packets number here and do actual
+				 * error processing when applications poll
+				 * completion
+				 */
+				pkt_err = pkt_burst_idx - n_pkts;
+				pkt_burst_idx = 0;
+				pkt_idx++;
+				break;
+			}
+
+			pkt_burst_idx = 0;
+		}
+	}
+
+	if (pkt_burst_idx) {
+		n_pkts = vq->async_ops.transfer_data(dev->vid, queue_id, tdes, 0, pkt_burst_idx);
+		vq->async_pkts_inflight_n += n_pkts;
+
+		if (unlikely(n_pkts < pkt_burst_idx))
+			pkt_err = pkt_burst_idx - n_pkts;
+	}
+
+	do_data_copy_enqueue(dev, vq);
+
+	if (unlikely(pkt_err))
+		dma_error_handler_packed(vq, async_descs, async_descs_idx, slot_idx, pkt_err,
+					&pkt_idx, &num_async_pkts, &num_done_pkts);
+	vq->async_pkts_idx += num_async_pkts;
+	*comp_count = num_done_pkts;
+
+	if (likely(vq->shadow_used_idx)) {
+		vhost_flush_enqueue_shadow_packed(dev, vq);
+		vhost_vring_call_packed(dev, vq);
+	}
+
+	return pkt_idx;
+}
+
 static __rte_always_inline void
 write_back_completed_descs_split(struct vhost_virtqueue *vq, uint16_t n_descs)
 {
@@ -1671,12 +2023,35 @@  write_back_completed_descs_split(struct vhost_virtqueue *vq, uint16_t n_descs)
 	} while (nr_left > 0);
 }
 
+static __rte_always_inline void
+write_back_completed_descs_packed(struct vhost_virtqueue *vq,
+				uint16_t n_buffers)
+{
+	uint16_t nr_left = n_buffers;
+	uint16_t from, to;
+
+	do {
+		from = vq->last_async_buffer_idx % vq->size;
+		to = (from + nr_left) % vq->size;
+		if (to > from) {
+			vhost_update_used_packed(vq, vq->async_buffers_packed + from, to - from);
+			vq->last_async_buffer_idx += nr_left;
+			nr_left = 0;
+		} else {
+			vhost_update_used_packed(vq, vq->async_buffers_packed + from,
+				vq->size - from);
+			vq->last_async_buffer_idx += vq->size - from;
+			nr_left -= vq->size - from;
+		}
+	} while (nr_left > 0);
+}
+
 uint16_t rte_vhost_poll_enqueue_completed(int vid, uint16_t queue_id,
 		struct rte_mbuf **pkts, uint16_t count)
 {
 	struct virtio_net *dev = get_device(vid);
 	struct vhost_virtqueue *vq;
-	uint16_t n_pkts_cpl = 0, n_pkts_put = 0, n_descs = 0;
+	uint16_t n_pkts_cpl = 0, n_pkts_put = 0, n_descs = 0, n_buffers = 0;
 	uint16_t start_idx, pkts_idx, vq_size;
 	struct async_inflight_info *pkts_info;
 	uint16_t from, i;
@@ -1701,7 +2076,7 @@  uint16_t rte_vhost_poll_enqueue_completed(int vid, uint16_t queue_id,
 
 	rte_spinlock_lock(&vq->access_lock);
 
-	pkts_idx = vq->async_pkts_idx & (vq->size - 1);
+	pkts_idx = vq->async_pkts_idx % vq->size;
 	pkts_info = vq->async_pkts_info;
 	vq_size = vq->size;
 	start_idx = virtio_dev_rx_async_get_info_idx(pkts_idx,
@@ -1718,21 +2093,41 @@  uint16_t rte_vhost_poll_enqueue_completed(int vid, uint16_t queue_id,
 		goto done;
 	}
 
-	for (i = 0; i < n_pkts_put; i++) {
-		from = (start_idx + i) & (vq_size - 1);
-		n_descs += pkts_info[from].descs;
-		pkts[i] = pkts_info[from].mbuf;
+	if (vq_is_packed(dev)) {
+		for (i = 0; i < n_pkts_put; i++) {
+			from = (start_idx + i) & (vq_size - 1);
+			n_buffers += pkts_info[from].nr_buffers;
+			pkts[i] = pkts_info[from].mbuf;
+		}
+	} else {
+		for (i = 0; i < n_pkts_put; i++) {
+			from = (start_idx + i) & (vq_size - 1);
+			n_descs += pkts_info[from].descs;
+			pkts[i] = pkts_info[from].mbuf;
+		}
 	}
+
 	vq->async_last_pkts_n = n_pkts_cpl - n_pkts_put;
 	vq->async_pkts_inflight_n -= n_pkts_put;
 
 	if (likely(vq->enabled && vq->access_ok)) {
-		write_back_completed_descs_split(vq, n_descs);
+		if (vq_is_packed(dev)) {
+			write_back_completed_descs_packed(vq, n_buffers);
 
-		__atomic_add_fetch(&vq->used->idx, n_descs, __ATOMIC_RELEASE);
-		vhost_vring_call_split(dev, vq);
-	} else
-		vq->last_async_desc_idx += n_descs;
+			vhost_vring_call_packed(dev, vq);
+		} else {
+			write_back_completed_descs_split(vq, n_descs);
+
+			__atomic_add_fetch(&vq->used->idx, n_descs,
+					__ATOMIC_RELEASE);
+			vhost_vring_call_split(dev, vq);
+		}
+	} else {
+		if (vq_is_packed(dev))
+			vq->last_async_buffer_idx += n_buffers;
+		else
+			vq->last_async_desc_idx += n_descs;
+	}
 
 done:
 	rte_spinlock_unlock(&vq->access_lock);
@@ -1773,9 +2168,10 @@  virtio_dev_rx_async_submit(struct virtio_net *dev, uint16_t queue_id,
 	if (count == 0)
 		goto out;
 
-	/* TODO: packed queue not implemented */
 	if (vq_is_packed(dev))
-		nb_tx = 0;
+		nb_tx = virtio_dev_rx_async_submit_packed(dev,
+				vq, queue_id, pkts, count, comp_pkts,
+				comp_count);
 	else
 		nb_tx = virtio_dev_rx_async_submit_split(dev,
 				vq, queue_id, pkts, count, comp_pkts,