Hi Cheng,
> -----Original Message-----
> From: Jiang, Cheng1 <cheng1.ji...@intel.com>
> Sent: Monday, January 4, 2021 12:58 PM
> To: maxime.coque...@redhat.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>; Jiang,
> Cheng1 <cheng1.ji...@intel.com>
> Subject: [PATCH v6 1/2] examples/vhost: add ioat ring space count and check
>
> Add ioat ring space count and check, if ioat ring space is not enough
> for the next async vhost packet enqueue, then just return to prevent
> enqueue failure. Add rte_ioat_completed_ops() fail handler.
>
> Signed-off-by: Cheng Jiang <cheng1.ji...@intel.com>
> ---
> examples/vhost/ioat.c | 22 ++++++++++++----------
> 1 file changed, 12 insertions(+), 10 deletions(-)
>
> diff --git a/examples/vhost/ioat.c b/examples/vhost/ioat.c
> index 71d8a1f1f5..679d1e2f58 100644
> --- a/examples/vhost/ioat.c
> +++ b/examples/vhost/ioat.c
> @@ -17,6 +17,7 @@ struct packet_tracker {
> unsigned short next_read;
> unsigned short next_write;
> unsigned short last_remain;
> + unsigned short ioat_space;
> };
>
> struct packet_tracker cb_tracker[MAX_VHOST_DEVICE];
> @@ -113,7 +114,7 @@ open_ioat(const char *value)
> goto out;
> }
> rte_rawdev_start(dev_id);
> -
> + cb_tracker[dev_id].ioat_space = IOAT_RING_SIZE;
> dma_info->nr++;
> i++;
> }
> @@ -140,13 +141,9 @@ ioat_transfer_data_cb(int vid, uint16_t queue_id,
> src = descs[i_desc].src;
> dst = descs[i_desc].dst;
> i_seg = 0;
> + if (cb_tracker[dev_id].ioat_space < src->nr_segs)
> + break;
> while (i_seg < src->nr_segs) {
> - /*
> - * TODO: Assuming that the ring space of the
> - * IOAT device is large enough, so there is no
> - * error here, and the actual error handling
> - * will be added later.
> - */
> rte_ioat_enqueue_copy(dev_id,
> (uintptr_t)(src->iov[i_seg].iov_base)
> + src->offset,
> @@ -158,7 +155,8 @@ ioat_transfer_data_cb(int vid, uint16_t queue_id,
> i_seg++;
> }
> write &= mask;
> - cb_tracker[dev_id].size_track[write] = i_seg;
> + cb_tracker[dev_id].size_track[write] = src->nr_segs;
> + cb_tracker[dev_id].ioat_space -= src->nr_segs;
> write++;
> }
> } else {
> @@ -178,17 +176,21 @@ ioat_check_completed_copies_cb(int vid, uint16_t
> queue_id,
> {
> if (!opaque_data) {
> uintptr_t dump[255];
> - unsigned short n_seg;
> + int n_seg;
> unsigned short read, write;
> unsigned short nb_packet = 0;
> unsigned short mask = MAX_ENQUEUED_SIZE - 1;
> unsigned short i;
> +
> int dev_id = dma_bind[vid].dmas[queue_id * 2
> + VIRTIO_RXQ].dev_id;
> n_seg = rte_ioat_completed_ops(dev_id, 255, dump, dump);
> - n_seg += cb_tracker[dev_id].last_remain;
> if (!n_seg)
> return 0;
> +
> + cb_tracker[dev_id].ioat_space += n_seg;
> + n_seg += cb_tracker[dev_id].last_remain;
When error happens in rte_ioat_completed_ops(), where n_seg is -1,
the value of "!n_seg" is false (0) and it can still pass the check of "if".
Thanks,
Jiayu
> +
> read = cb_tracker[dev_id].next_read;
> write = cb_tracker[dev_id].next_write;
> for (i = 0; i < max_packets; i++) {
> --
> 2.29.2
