[dpdk-dev] [PATCH] net/netvsc: use memzone to allocate contiguous physical mem for rndis

[Long Li <longli@linuxonhyperv.com>]

From: Long Li <longli@microsoft.com>

When sending data, netvsc assumes the tx_rndis buffer is contiguous and
calculates physical addresses based on this assumption.

Use memzone to allocate tx_rndis so it's guaranteed that this buffer is
physically contiguous.

Cc:stable@dpdk.org
Signed-off-by: Long Li <longli@microsoft.com>
---
 drivers/net/netvsc/hn_rxtx.c | 23 ++++++++++++-----------
 drivers/net/netvsc/hn_var.h  |  2 ++
 2 files changed, 14 insertions(+), 11 deletions(-)

diff --git a/drivers/net/netvsc/hn_rxtx.c b/drivers/net/netvsc/hn_rxtx.c
index cea3157ca7..65d0725b16 100644
--- a/drivers/net/netvsc/hn_rxtx.c
+++ b/drivers/net/netvsc/hn_rxtx.c
@@ -280,10 +280,15 @@ hn_dev_tx_queue_setup(struct rte_eth_dev *dev,
 	PMD_INIT_LOG(DEBUG, "TX descriptor pool %s n=%u size=%zu",
 		     name, nb_desc, sizeof(struct hn_txdesc));
 
-	txq->tx_rndis = rte_calloc("hn_txq_rndis", nb_desc,
-				   HN_RNDIS_PKT_ALIGNED, RTE_CACHE_LINE_SIZE);
-	if (txq->tx_rndis == NULL)
+	txq->tx_rndis_mz = rte_memzone_reserve_aligned(name,
+			nb_desc * HN_RNDIS_PKT_ALIGNED, rte_socket_id(),
+			RTE_MEMZONE_IOVA_CONTIG, HN_RNDIS_PKT_ALIGNED);
+	if (!txq->tx_rndis_mz) {
+		err = -rte_errno;
 		goto error;
+	}
+	txq->tx_rndis = txq->tx_rndis_mz->addr;
+	txq->tx_rndis_iova = txq->tx_rndis_mz->iova;
 
 	txq->txdesc_pool = rte_mempool_create(name, nb_desc,
 					      sizeof(struct hn_txdesc),
@@ -312,7 +317,7 @@ hn_dev_tx_queue_setup(struct rte_eth_dev *dev,
 error:
 	if (txq->txdesc_pool)
 		rte_mempool_free(txq->txdesc_pool);
-	rte_free(txq->tx_rndis);
+	rte_memzone_free(txq->tx_rndis_mz);
 	rte_free(txq);
 	return err;
 }
@@ -363,7 +368,7 @@ hn_dev_tx_queue_release(void *arg)
 	if (txq->txdesc_pool)
 		rte_mempool_free(txq->txdesc_pool);
 
-	rte_free(txq->tx_rndis);
+	rte_memzone_free(txq->tx_rndis_mz);
 	rte_free(txq);
 }
 
@@ -1442,12 +1447,8 @@ static int hn_xmit_sg(struct hn_tx_queue *txq,
 	hn_rndis_dump(txd->rndis_pkt);
 
 	/* pass IOVA of rndis header in first segment */
-	addr = rte_malloc_virt2iova(txq->tx_rndis);
-	if (unlikely(addr == RTE_BAD_IOVA)) {
-		PMD_DRV_LOG(ERR, "RNDIS transmit can not get iova");
-		return -EINVAL;
-	}
-	addr = addr + ((char *)txd->rndis_pkt - (char *)txq->tx_rndis);
+	addr = txq->tx_rndis_iova +
+		((char *)txd->rndis_pkt - (char *)txq->tx_rndis);
 
 	sg[0].page = addr / PAGE_SIZE;
 	sg[0].ofs = addr & PAGE_MASK;
diff --git a/drivers/net/netvsc/hn_var.h b/drivers/net/netvsc/hn_var.h
index 9dcb669f7a..bd874c6b4d 100644
--- a/drivers/net/netvsc/hn_var.h
+++ b/drivers/net/netvsc/hn_var.h
@@ -59,7 +59,9 @@ struct hn_tx_queue {
 	uint16_t	queue_id;
 	uint32_t	free_thresh;
 	struct rte_mempool *txdesc_pool;
+	const struct rte_memzone *tx_rndis_mz;
 	void		*tx_rndis;
+	rte_iova_t	tx_rndis_iova;
 
 	/* Applied packet transmission aggregation limits. */
 	uint32_t	agg_szmax;
-- 
2.25.1