On 4/13/21 1:48 PM, Jiang, Cheng1 wrote:
> Hi Maxime,
>
>> -----Original Message-----
>> From: Maxime Coquelin <maxime.coque...@redhat.com>
>> Sent: Tuesday, April 13, 2021 4:37 PM
>> To: Jiang, Cheng1 <cheng1.ji...@intel.com>; Xia, Chenbo
>> <chenbo....@intel.com>
>> Cc: dev@dpdk.org; Hu, Jiayu <jiayu...@intel.com>; Yang, YvonneX
>> <yvonnex.y...@intel.com>; Wang, Yinan <yinan.w...@intel.com>; Liu,
>> Yong <yong....@intel.com>
>> Subject: Re: [PATCH v5 2/4] vhost: add support for packed ring in async vhost
>>
>>
>>
>> On 4/12/21 1:34 PM, Cheng Jiang wrote:
>>> For now async vhost data path only supports split ring structure. In
>>> order to make async vhost compatible with virtio 1.1 spec this patch
>>> enables packed ring in async vhost data path.
>>>
>>> Signed-off-by: Cheng Jiang <cheng1.ji...@intel.com>
>>> ---
>>> lib/librte_vhost/rte_vhost_async.h | 1 +
>>> lib/librte_vhost/vhost.c | 27 +-
>>> lib/librte_vhost/vhost.h | 7 +-
>>> lib/librte_vhost/virtio_net.c | 438 +++++++++++++++++++++++++++--
>>> 4 files changed, 448 insertions(+), 25 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..8c9935c0f 100644
>>> --- a/lib/librte_vhost/vhost.c
>>> +++ b/lib/librte_vhost/vhost.c
>>> @@ -342,15 +342,21 @@ vhost_free_async_mem(struct vhost_virtqueue
>> *vq)
>>> {
>>> if (vq->async_pkts_info)
>>> rte_free(vq->async_pkts_info);
>>> - if (vq->async_descs_split)
>>> + if (vq->async_buffers_packed) {
>>> + rte_free(vq->async_buffers_packed);
>>> + vq->async_buffers_packed = NULL;
>>> + }
>>> + if (vq->async_descs_split) {
>>
>> You can remove the check, rte_free is safe with NULL pointers.
>> You can do the same for the other ones in this function.
>
> OK, it will be fixed.
>
>>
>>> rte_free(vq->async_descs_split);
>>> + vq->async_descs_split = NULL;
>>> + }
>>> +
>>> if (vq->it_pool)
>>> rte_free(vq->it_pool);
>>> if (vq->vec_pool)
>>> rte_free(vq->vec_pool);
>>>
>>> vq->async_pkts_info = NULL;
>>> - vq->async_descs_split = NULL;
>>> vq->it_pool = NULL;
>>> vq->vec_pool = NULL;
>>> }
>>> @@ -1627,9 +1633,9 @@ int rte_vhost_async_channel_register(int vid,
>> uint16_t queue_id,
>>> 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;
>>> }
>>> @@ -1667,11 +1673,18 @@ 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) {
>>> + }
>>> +
>>> + if (!vq->async_buffers_packed || !vq->async_descs_split ||
>>> + !vq->async_pkts_info || !vq->it_pool || !vq->vec_pool) {
>>> vhost_free_async_mem(vq);
>>> VHOST_LOG_CONFIG(ERR,
>>> "async register failed: cannot allocate
>> memory for vq data "
>>> diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h index
>>> f628714c2..fe131ae8f 100644
>>> --- a/lib/librte_vhost/vhost.h
>>> +++ b/lib/librte_vhost/vhost.h
>>> @@ -201,9 +201,14 @@ 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;
>>> + union {
>>> + struct vring_used_elem *async_descs_split;
>>> + struct vring_used_elem_packed *async_buffers_packed;
>>> + };
>>> uint16_t async_desc_idx;
>>> + uint16_t async_packed_buffer_idx;
>>
>> Don't dupplicate variable names, async_desc_idx can be reused for packed
>> ring. Also, they are representing the same thing, why use desc in one case
>> and buffer in the other?
>
> The main reason is that the unit of the packed used ring is buffer, which can
> contain many desc.
> I think using desc_idx will cause ambiguity, but if you think that I should
> reuse the desc_idx, I have no problem with that.
OK, in this case please use a union not to waste memory.
>>
>>> uint16_t last_async_desc_idx;
>>> + uint16_t last_async_buffer_idx;
>>
>> Same remark here.
>>
>>> /* vq async features */
>>> bool async_inorder;
>>> diff --git a/lib/librte_vhost/virtio_net.c
>>> b/lib/librte_vhost/virtio_net.c index c43ab0093..410be9678 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);
>>> @@ -1481,6 +1492,62 @@ shadow_ring_store(struct vhost_virtqueue *vq,
>> void *shadow_ring, void *d_ring,
>>> }
>>> }
>>>
>>> +static __rte_always_inline void
>>> +vhost_update_used_packed(struct vhost_virtqueue *vq,
>>> + struct vring_used_elem_packed *shadow_ring,
>>> + uint16_t count)
>>> +{
>>> + if (count == 0)
>>> + return;
>>
>> Move this after the variables declaration.
>
> Sure.
>
>>
>>> +
>>> + int i;
>>> + uint16_t used_idx = vq->last_used_idx;
>>> + uint16_t head_idx = vq->last_used_idx;
>>> + uint16_t head_flags = 0;
>>> +
>>> + /* 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_noinline uint32_t
>>> virtio_dev_rx_async_submit_split(struct virtio_net *dev,
>>> struct vhost_virtqueue *vq, uint16_t queue_id, @@ -1656,6
>> +1723,294
>>> @@ virtio_dev_rx_async_submit_split(struct virtio_net *dev,
>>> return pkt_idx;
>>> }
>>>
>>> +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));
>>
>> Please add brackets for the 'if' since there are for the 'else'.
>
> Sure, sorry for that.
>
>>
>>> + 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_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);
>>> + struct rte_vhost_iov_iter *src_it = it_pool;
>>> + struct rte_vhost_iov_iter *dst_it = it_pool + 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 & (vq->size -
>>> +1)]);
>>
>> The size of the ring is not necessarily a power of two with packed ring.
>
> For the size of the ring is not necessarily a power of two,
> so maybe I can use codes like
> Indx % vq->size ?
> I'm not sure if it's a good way to do that.
In this case it is OK.
>>
>>> +
>>> + 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],
>>> + &src_it[it_idx],
>>> + &dst_it[it_idx]) < 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 - 1);
>>
>> Same here.
>
> Sure.
>
>>
>>> + if (src_it[it_idx].count) {
>>> + uint16_t from, to;
>>> +
>>> + async_descs_idx += num_desc;
>>> + async_fill_desc(&tdes[pkt_burst_idx++],
>> &src_it[it_idx],
>>> + &dst_it[it_idx]);
>>> + 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 += src_it[it_idx].nr_segs;
>>> + it_idx += 2;
>>> +
>>> + segs_await += src_it[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 - 1);
>>> + shadow_ring_store(vq, vq->shadow_used_packed,
>>> + vq->async_buffers_packed,
>>> + from, to, num_buffers,
>>> + sizeof(struct
>> vring_used_elem_packed));
>>> +
>>> + vq->async_packed_buffer_idx += num_buffers;
>>> + vq->shadow_used_idx -= num_buffers;
>>> + } else
>>
>> Brackets needed.
>
> Sure.
>
>>
>>> + 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)) {
>>> + uint16_t descs_err = 0;
>>> + uint16_t buffers_err = 0;
>>> +
>>> + num_async_pkts -= pkt_err;
>>> + pkt_idx -= pkt_err;
>>> + /* calculate the sum of buffers and descs of DMA-error packets. */
>>> + while (pkt_err-- > 0) {
>>> + descs_err +=
>>> + pkts_info[slot_idx & (vq->size - 1)].descs;
>>
>> The size of the ring is not necessarily a power of two with packed ring.
>
> Will be fixed.
>
>>
>>> + buffers_err +=
>>> + pkts_info[slot_idx & (vq->size -
>> 1)].nr_buffers;
>>
>> Ditto.
>
> Will be fixed.
>
>>
>>> + 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,
>>> + &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;
>>> + }
>>
>> This error handling could be moved in a dedicated function.
>
> Sure, will fix it in the next version.
>
>>
>>> + 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;
>>> +}
>>
>> Above function is very big and complex, it should be possible to split it in
>> several ones to make it maintainable.
>
> I think move the error handling code will make it smaller.
>
> Thanks.
> Cheng
>
>>
>>> +
>>> static __rte_always_inline void
>>> write_back_completed_descs_split(struct vhost_virtqueue *vq, uint16_t
>>> n_descs) { @@ -1693,12 +2048,40 @@
>>> 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 - 1);
>>> + to = (from + nr_left) & (vq->size - 1);
>>
>> The size of the ring is not necessarily a power of two with packed ring.
>
> Sure.
>
>>
>>> + 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;
>>> @@ -1740,21 +2123,41 @@ 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);
>>
>> Unlike split ring, packed ring size is not necessarily a power of 2.
>
> Sure.
> Thanks.
>
>>
>>> + 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);
>>> @@ -1795,9 +2198,10 @@ 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,
>>>
>
