[dpdk-dev] [PATCH v9 1/2] examples/vhost: add ioat ring space count and check

[Cheng Jiang]

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.jiang at intel.com>
Reviewed-by: Jiayu Hu <jiayu.hu at intel.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin at redhat.com>
---
 examples/vhost/ioat.c | 24 +++++++++++++-----------
 1 file changed, 13 insertions(+), 11 deletions(-)

diff --git a/examples/vhost/ioat.c b/examples/vhost/ioat.c
index 71d8a1f1f..dbad28d43 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)
+		if (n_seg <= 0)
 			return 0;
+
+		cb_tracker[dev_id].ioat_space += n_seg;
+		n_seg += cb_tracker[dev_id].last_remain;
+
 		read = cb_tracker[dev_id].next_read;
 		write = cb_tracker[dev_id].next_write;
 		for (i = 0; i < max_packets; i++) {
--
2.29.2