Hi Maxime,
> -----Original Message-----
> From: Maxime Coquelin <maxime.coque...@redhat.com>
> Sent: Friday, October 21, 2022 4:16 PM
> To: Jiang, Cheng1 <cheng1.ji...@intel.com>; Xia, Chenbo
> <chenbo....@intel.com>
> Cc: dev@dpdk.org; Hu, Jiayu <jiayu...@intel.com>; Ding, Xuan
> <xuan.d...@intel.com>; Ma, WenwuX <wenwux...@intel.com>; Wang,
> YuanX <yuanx.w...@intel.com>; Yang, YvonneX
> <yvonnex.y...@intel.com>; He, Xingguang <xingguang...@intel.com>;
> sta...@dpdk.org
> Subject: Re: [PATCH v2 1/2] vhost: fix descs count in async vhost packed ring
>
>
>
> On 10/11/22 05:08, Cheng Jiang wrote:
> > When vhost receive packets from the front-end using packed virtqueue,
> > it
>
> receives
>
> > might use multiple descriptors for one packet, so we need calculate
> > and
>
> to calculate
>
> > record the descriptor number for each packet to update available
> > descriptor counter and used descriptor counter, and rollback when DMA
> > ring is full.
> >
> > Fixes: fe8477ebbd94 ("vhost: support async packed ring dequeue")
> > Cc: sta...@dpdk.org
> >
> > Signed-off-by: Cheng Jiang <cheng1.ji...@intel.com>
> > ---
> > lib/vhost/virtio_net.c | 24 +++++++++++++++---------
> > 1 file changed, 15 insertions(+), 9 deletions(-)
> >
> > diff --git a/lib/vhost/virtio_net.c b/lib/vhost/virtio_net.c index
> > 8f4d0f0502..457ac2e92a 100644
> > --- a/lib/vhost/virtio_net.c
> > +++ b/lib/vhost/virtio_net.c
> > @@ -3548,14 +3548,15 @@ virtio_dev_tx_async_split_compliant(struct
> virtio_net *dev,
> > }
> >
> > static __rte_always_inline void
> > -vhost_async_shadow_dequeue_single_packed(struct vhost_virtqueue
> *vq,
> > uint16_t buf_id)
> > +vhost_async_shadow_dequeue_single_packed(struct vhost_virtqueue
> *vq,
> > + uint16_t buf_id, uint16_t count)
> > {
> > struct vhost_async *async = vq->async;
> > uint16_t idx = async->buffer_idx_packed;
> >
> > async->buffers_packed[idx].id = buf_id;
> > async->buffers_packed[idx].len = 0;
> > - async->buffers_packed[idx].count = 1;
> > + async->buffers_packed[idx].count = count;
> >
> > async->buffer_idx_packed++;
> > if (async->buffer_idx_packed >= vq->size) @@ -3576,6 +3577,8 @@
> > virtio_dev_tx_async_single_packed(struct virtio_net *dev,
> > uint16_t nr_vec = 0;
> > uint32_t buf_len;
> > struct buf_vector buf_vec[BUF_VECTOR_MAX];
> > + struct vhost_async *async = vq->async;
> > + struct async_inflight_info *pkts_info = async->pkts_info;
> > static bool allocerr_warned;
> >
> > if (unlikely(fill_vec_buf_packed(dev, vq, vq->last_avail_idx,
> > &desc_count, @@ -3604,8 +3607,12 @@
> virtio_dev_tx_async_single_packed(struct virtio_net *dev,
> > return -1;
> > }
> >
> > + pkts_info[slot_idx].descs = desc_count;
> > +
> > /* update async shadow packed ring */
> > - vhost_async_shadow_dequeue_single_packed(vq, buf_id);
> > + vhost_async_shadow_dequeue_single_packed(vq, buf_id,
> desc_count);
> > +
> > + vq_inc_last_avail_packed(vq, desc_count);
> >
> > return err;
> > }
> > @@ -3644,9 +3651,6 @@ virtio_dev_tx_async_packed(struct virtio_net
> *dev, struct vhost_virtqueue *vq,
> > }
> >
> > pkts_info[slot_idx].mbuf = pkt;
> > -
> > - vq_inc_last_avail_packed(vq, 1);
> > -
> > }
> >
> > n_xfer = vhost_async_dma_transfer(dev, vq, dma_id, vchan_id,
> > async->pkts_idx, @@ -3657,6 +3661,8 @@
> virtio_dev_tx_async_packed(struct virtio_net *dev, struct vhost_virtqueue
> *vq,
> > pkt_err = pkt_idx - n_xfer;
> >
> > if (unlikely(pkt_err)) {
> > + uint16_t descs_err = 0;
> > +
> > pkt_idx -= pkt_err;
> >
> > /**
> > @@ -3673,10 +3679,10 @@ virtio_dev_tx_async_packed(struct virtio_net
> *dev, struct vhost_virtqueue *vq,
> > }
> >
> > /* recover available ring */
> > - if (vq->last_avail_idx >= pkt_err) {
> > - vq->last_avail_idx -= pkt_err;
> > + if (vq->last_avail_idx >= descs_err) {
> > + vq->last_avail_idx -= descs_err;
> > } else {
> > - vq->last_avail_idx += vq->size - pkt_err;
> > + vq->last_avail_idx += vq->size - descs_err;
> > vq->avail_wrap_counter ^= 1;
> > }
> > }
>
> If only the commit message typos need to be fixed, maybe no need to send
> a new version.
Sure, thanks a lot!
Cheng
>
> Reviewed-by: Maxime Coquelin <maxime.coque...@redhat.com>
>
> Thanks,
> Maxime
