[dpdk-dev] [PATCH 4/7] net/netvsc: check the vmbus ring buffer more often

[Stephen Hemminger <stephen@networkplumber.org>]

Since VF notfications are handled as VMBUS notifications on the
primary channel (and not as hotplug). The channel should be checked
before deciding to use VF for Rx or Tx.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---
 drivers/net/netvsc/hn_rxtx.c | 22 ++++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/drivers/net/netvsc/hn_rxtx.c b/drivers/net/netvsc/hn_rxtx.c
index 19f00a05285f..773ba31fcc64 100644
--- a/drivers/net/netvsc/hn_rxtx.c
+++ b/drivers/net/netvsc/hn_rxtx.c
@@ -1372,25 +1372,29 @@ hn_xmit_pkts(void *ptxq, struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
 	struct hn_data *hv = txq->hv;
 	struct rte_eth_dev *vf_dev;
 	bool need_sig = false;
-	uint16_t nb_tx, avail;
+	uint16_t nb_tx, tx_thresh;
 	int ret;
 
 	if (unlikely(hv->closed))
 		return 0;
 
+	/*
+	 * Always check for events on the primary channel
+	 * because that is where hotplug notifications occur.
+	 */
+	tx_thresh = RTE_MAX(txq->free_thresh, nb_pkts);
+	if (txq->queue_id == 0 ||
+	    rte_mempool_avail_count(txq->txdesc_pool) < tx_thresh)
+		hn_process_events(hv, txq->queue_id, 0);
+
 	/* Transmit over VF if present and up */
 	vf_dev = hn_get_vf_dev(hv);
-
 	if (vf_dev && vf_dev->data->dev_started) {
 		void *sub_q = vf_dev->data->tx_queues[queue_id];
 
 		return (*vf_dev->tx_pkt_burst)(sub_q, tx_pkts, nb_pkts);
 	}
 
-	avail = rte_mempool_avail_count(txq->txdesc_pool);
-	if (nb_pkts > avail || avail <= txq->free_thresh)
-		hn_process_events(hv, txq->queue_id, 0);
-
 	for (nb_tx = 0; nb_tx < nb_pkts; nb_tx++) {
 		struct rte_mbuf *m = tx_pkts[nb_tx];
 		uint32_t pkt_size = m->pkt_len + HN_RNDIS_PKT_LEN;
@@ -1487,10 +1491,7 @@ hn_recv_pkts(void *prxq, struct rte_mbuf **rx_pkts, uint16_t nb_pkts)
 	if (unlikely(hv->closed))
 		return 0;
 
-	/* Receive from VF if present and up */
-	vf_dev = hn_get_vf_dev(hv);
-
-	/* Check for new completions */
+	/* Check for new completions (and hotplug) */
 	if (likely(rte_ring_count(rxq->rx_ring) < nb_pkts))
 		hn_process_events(hv, rxq->queue_id, 0);
 
@@ -1499,6 +1500,7 @@ hn_recv_pkts(void *prxq, struct rte_mbuf **rx_pkts, uint16_t nb_pkts)
 					   (void **)rx_pkts, nb_pkts, NULL);
 
 	/* If VF is available, check that as well */
+	vf_dev = hn_get_vf_dev(hv);
 	if (vf_dev && vf_dev->data->dev_started)
 		nb_rcv += hn_recv_vf(vf_dev->data->port_id, rxq,
 				     rx_pkts + nb_rcv, nb_pkts - nb_rcv);
-- 
2.20.1