Re: [dpdk-dev] [PATCH] net/af_xdp: enable support for unaligned umem chunks

[Ye Xiaolong <xiaolong.ye@intel.com>]

Hi, Ciara

Thanks for the patch, the performance number is quite impressive.

On 08/29, Ciara Loftus wrote:
>This patch enables the unaligned chunks feature for AF_XDP which allows
>chunks to be placed at arbitrary places in the umem, as opposed to them
>being required to be aligned to 2k. This allows for DPDK application
>mempools to be mapped directly into the umem and in turn enable zero copy
>transfer between umem and the PMD.
>
>This patch replaces the zero copy via external mbuf mechanism introduced
>in commit e9ff8bb71943 ("net/af_xdp: enable zero copy by external mbuf").
>The pmd_zero copy vdev argument is also removed as now the PMD will
>auto-detect presence of the unaligned chunks feature and enable it if so
>and otherwise fall back to copy mode if not detected.
>
>When enabled, this feature significantly improves single-core performance
>of the PMD.
>
>Signed-off-by: Ciara Loftus <ciara.loftus@intel.com>
>Signed-off-by: Kevin Laatz <kevin.laatz@intel.com>
>---
> doc/guides/nics/af_xdp.rst             |   1 -
> doc/guides/rel_notes/release_19_11.rst |   9 +
> drivers/net/af_xdp/rte_eth_af_xdp.c    | 304 ++++++++++++++++++-------
> 3 files changed, 231 insertions(+), 83 deletions(-)
>
>diff --git a/doc/guides/nics/af_xdp.rst b/doc/guides/nics/af_xdp.rst
>index ec46f08f0..48dd788ac 100644
>--- a/doc/guides/nics/af_xdp.rst
>+++ b/doc/guides/nics/af_xdp.rst
>@@ -35,7 +35,6 @@ The following options can be provided to set up an af_xdp port in DPDK.
> *   ``iface`` - name of the Kernel interface to attach to (required);
> *   ``start_queue`` - starting netdev queue id (optional, default 0);
> *   ``queue_count`` - total netdev queue number (optional, default 1);
>-*   ``pmd_zero_copy`` - enable zero copy or not (optional, default 0);
> 
> Prerequisites
> -------------
>diff --git a/doc/guides/rel_notes/release_19_11.rst b/doc/guides/rel_notes/release_19_11.rst
>index 8490d897c..28a8e5372 100644
>--- a/doc/guides/rel_notes/release_19_11.rst
>+++ b/doc/guides/rel_notes/release_19_11.rst
>@@ -56,6 +56,13 @@ New Features
>      Also, make sure to start the actual text at the margin.
>      =========================================================
> 
>+* **Updated the AF_XDP PMD.**
>+
>+  Updated the AF_XDP PMD. The new features include:
>+
>+  * Enabled zero copy between application mempools and UMEM by enabling the
>+    XDP_UMEM_UNALIGNED_CHUNKS UMEM flag.
>+

Better to document the kernel dependency in the af_xdp.rst.

> 
> Removed Items
> -------------
>@@ -69,6 +76,8 @@ Removed Items
>    Also, make sure to start the actual text at the margin.
>    =========================================================
> 
>+* Removed AF_XDP pmd_zero copy vdev argument. Support is now auto-detected.
>+
> 
> API Changes
> -----------
>diff --git a/drivers/net/af_xdp/rte_eth_af_xdp.c b/drivers/net/af_xdp/rte_eth_af_xdp.c
>index 41ed5b2af..7956d5778 100644
>--- a/drivers/net/af_xdp/rte_eth_af_xdp.c
>+++ b/drivers/net/af_xdp/rte_eth_af_xdp.c
[snip]
> reserve_fill_queue(struct xsk_umem_info *umem, uint16_t reserve_size)
> {
> 	struct xsk_ring_prod *fq = &umem->fq;
>-	void *addrs[reserve_size];
> 	uint32_t idx;
> 	uint16_t i;
>+#if defined(XDP_UMEM_UNALIGNED_CHUNK_FLAG)
>+
>+	if (unlikely(!xsk_ring_prod__reserve(fq, reserve_size, &idx))) {
>+		AF_XDP_LOG(DEBUG, "Failed to reserve enough fq descs.\n");
>+		return -1;
>+	}
>+
>+	for (i = 0; i < reserve_size; i++) {
>+		struct rte_mbuf *mbuf;
>+		__u64 *fq_addr;
>+		uint64_t addr;
>+
>+		mbuf = rte_pktmbuf_alloc(umem->mb_pool);
>+		if (unlikely(mbuf == NULL))
>+			break;

If this rare case happens, not all of the reserved slots of fq will be filled
with proper mbuf addr, then we just call xsk_ring_prod__submit(fq, reserve_size)
to let kernel receive packets on these addrs, something unexpected may happen.

Thanks,
Xiaolong

>+
>+		fq_addr = xsk_ring_prod__fill_addr(fq, idx++);
>+		addr = (uint64_t)mbuf - (uint64_t)umem->buffer;
>+		*fq_addr = addr;
>+	}
>+#else
>+	void *addrs[reserve_size];
> 
> 	if (rte_ring_dequeue_bulk(umem->buf_ring, addrs, reserve_size, NULL)
> 		    != reserve_size) {
>@@ -171,21 +198,13 @@ reserve_fill_queue(struct xsk_umem_info *umem, uint16_t reserve_size)
> 		fq_addr = xsk_ring_prod__fill_addr(fq, idx++);
> 		*fq_addr = (uint64_t)addrs[i];
> 	}
>+#endif
> 
> 	xsk_ring_prod__submit(fq, reserve_size);
> 
> 	return 0;
> }
> 
>-static void
>-umem_buf_release_to_fq(void *addr, void *opaque)
>-{
>-	struct xsk_umem_info *umem = (struct xsk_umem_info *)opaque;
>-	uint64_t umem_addr = (uint64_t)addr - umem->mz->addr_64;
>-
>-	rte_ring_enqueue(umem->buf_ring, (void *)umem_addr);
>-}
>-
> static uint16_t
> eth_af_xdp_rx(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
> {
>@@ -194,12 +213,53 @@ eth_af_xdp_rx(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
> 	struct xsk_umem_info *umem = rxq->umem;
> 	struct xsk_ring_prod *fq = &umem->fq;
> 	uint32_t idx_rx = 0;
>-	uint32_t free_thresh = fq->size >> 1;
>-	int pmd_zc = umem->pmd_zc;
>-	struct rte_mbuf *mbufs[ETH_AF_XDP_RX_BATCH_SIZE];
> 	unsigned long dropped = 0;
> 	unsigned long rx_bytes = 0;
> 	int rcvd, i;
>+#if defined(XDP_UMEM_UNALIGNED_CHUNK_FLAG)
>+
>+	rcvd = xsk_ring_cons__peek(rx, nb_pkts, &idx_rx);
>+	if (rcvd == 0) {
>+#if defined(XDP_USE_NEED_WAKEUP)
>+		if (xsk_ring_prod__needs_wakeup(fq))
>+			(void)poll(rxq->fds, 1, 1000);
>+#endif
>+
>+		return rcvd;
>+	}
>+
>+	for (i = 0; i < rcvd; i++) {
>+		const struct xdp_desc *desc;
>+		uint64_t addr;
>+		uint32_t len;
>+		uint64_t offset;
>+
>+		desc = xsk_ring_cons__rx_desc(rx, idx_rx++);
>+		addr = desc->addr;
>+		len = desc->len;
>+
>+		offset = xsk_umem__extract_offset(addr);
>+		addr = xsk_umem__extract_addr(addr);
>+
>+		bufs[i] = (struct rte_mbuf *)
>+				xsk_umem__get_data(umem->buffer, addr);
>+		bufs[i]->data_off = offset - sizeof(struct rte_mbuf);
>+
>+		rte_pktmbuf_pkt_len(bufs[i]) = len;
>+		rte_pktmbuf_data_len(bufs[i]) = len;
>+		rx_bytes += len;
>+	}
>+
>+	xsk_ring_cons__release(rx, rcvd);
>+
>+	/* statistics */
>+	rxq->stats.rx_pkts += (rcvd - dropped);
>+	rxq->stats.rx_bytes += rx_bytes;
>+
>+	(void)reserve_fill_queue(umem, rcvd);
>+#else
>+	uint32_t free_thresh = fq->size >> 1;
>+	struct rte_mbuf *mbufs[ETH_AF_XDP_RX_BATCH_SIZE];
> 
> 	nb_pkts = RTE_MIN(nb_pkts, ETH_AF_XDP_RX_BATCH_SIZE);
> 
>@@ -224,25 +284,14 @@ eth_af_xdp_rx(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
> 		uint64_t addr;
> 		uint32_t len;
> 		void *pkt;
>-		uint16_t buf_len = ETH_AF_XDP_FRAME_SIZE;
>-		struct rte_mbuf_ext_shared_info *shinfo;
> 
> 		desc = xsk_ring_cons__rx_desc(rx, idx_rx++);
> 		addr = desc->addr;
> 		len = desc->len;
> 		pkt = xsk_umem__get_data(rxq->umem->mz->addr, addr);
> 
>-		if (pmd_zc) {
>-			shinfo = rte_pktmbuf_ext_shinfo_init_helper(pkt,
>-					&buf_len, umem_buf_release_to_fq, umem);
>-
>-			rte_pktmbuf_attach_extbuf(mbufs[i], pkt, 0, buf_len,
>-						  shinfo);
>-		} else {
>-			rte_memcpy(rte_pktmbuf_mtod(mbufs[i], void *),
>-							pkt, len);
>-			rte_ring_enqueue(umem->buf_ring, (void *)addr);
>-		}
>+		rte_memcpy(rte_pktmbuf_mtod(mbufs[i], void *), pkt, len);
>+		rte_ring_enqueue(umem->buf_ring, (void *)addr);
> 		rte_pktmbuf_pkt_len(mbufs[i]) = len;
> 		rte_pktmbuf_data_len(mbufs[i]) = len;
> 		rx_bytes += len;
>@@ -259,6 +308,7 @@ eth_af_xdp_rx(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
> 	if (rcvd != nb_pkts)
> 		rte_mempool_put_bulk(rxq->mb_pool, (void **)&mbufs[rcvd],
> 				     nb_pkts - rcvd);
>+#endif
> 
> 	return rcvd;
> }
>@@ -275,7 +325,14 @@ pull_umem_cq(struct xsk_umem_info *umem, int size)
> 	for (i = 0; i < n; i++) {
> 		uint64_t addr;
> 		addr = *xsk_ring_cons__comp_addr(cq, idx_cq++);
>+
>+#if defined(XDP_UMEM_UNALIGNED_CHUNK_FLAG)
>+		addr = xsk_umem__extract_addr(addr);
>+		rte_pktmbuf_free((struct rte_mbuf *)
>+					xsk_umem__get_data(umem->buffer, addr));
>+#else
> 		rte_ring_enqueue(umem->buf_ring, (void *)addr);
>+#endif
> 	}
> 
> 	xsk_ring_cons__release(cq, n);
>@@ -284,7 +341,7 @@ pull_umem_cq(struct xsk_umem_info *umem, int size)
> static void
> kick_tx(struct pkt_tx_queue *txq)
> {
>-	struct xsk_umem_info *umem = txq->pair->umem;
>+	struct xsk_umem_info *umem = txq->umem;
> 
> #if defined(XDP_USE_NEED_WAKEUP)
> 	if (xsk_ring_prod__needs_wakeup(&txq->tx))
>@@ -299,28 +356,70 @@ kick_tx(struct pkt_tx_queue *txq)
> 			if (errno == EAGAIN)
> 				pull_umem_cq(umem, ETH_AF_XDP_TX_BATCH_SIZE);
> 		}
>-	pull_umem_cq(umem, ETH_AF_XDP_TX_BATCH_SIZE);
>-}
>-
>-static inline bool
>-in_umem_range(struct xsk_umem_info *umem, uint64_t addr)
>-{
>-	uint64_t mz_base_addr = umem->mz->addr_64;
>-
>-	return addr >= mz_base_addr && addr < mz_base_addr + umem->mz->len;
> }
> 
> static uint16_t
> eth_af_xdp_tx(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
> {
> 	struct pkt_tx_queue *txq = queue;
>-	struct xsk_umem_info *umem = txq->pair->umem;
>+	struct xsk_umem_info *umem = txq->umem;
> 	struct rte_mbuf *mbuf;
>-	int pmd_zc = umem->pmd_zc;
>-	void *addrs[ETH_AF_XDP_TX_BATCH_SIZE];
> 	unsigned long tx_bytes = 0;
> 	int i;
> 	uint32_t idx_tx;
>+	uint16_t dropped = 0;
>+#if defined(XDP_UMEM_UNALIGNED_CHUNK_FLAG)
>+
>+	pull_umem_cq(umem, nb_pkts);
>+
>+	nb_pkts = xsk_ring_prod__reserve(&txq->tx, nb_pkts, &idx_tx);
>+
>+	for (i = 0; i < nb_pkts; i++) {
>+		struct xdp_desc *desc;
>+		uint64_t addr, offset;
>+
>+		desc = xsk_ring_prod__tx_desc(&txq->tx, idx_tx + i);
>+		mbuf = bufs[i];
>+		desc->len = mbuf->pkt_len;
>+
>+		if (mbuf->pool == umem->mb_pool) {
>+			addr = (uint64_t)mbuf - (uint64_t)umem->buffer;
>+			offset = rte_pktmbuf_mtod(mbuf, uint64_t) -
>+					(uint64_t)mbuf;
>+			offset = offset << XSK_UNALIGNED_BUF_OFFSET_SHIFT;
>+			desc->addr = addr;
>+			desc->addr |= offset;
>+		} else {
>+			struct rte_mbuf *local_mbuf =
>+					rte_pktmbuf_alloc(umem->mb_pool);
>+			void *pkt;
>+
>+			if (!local_mbuf) {
>+				rte_pktmbuf_free(mbuf);
>+				dropped++;
>+				continue;
>+			}
>+
>+			addr = (uint64_t)local_mbuf - (uint64_t)umem->buffer;
>+			offset = rte_pktmbuf_mtod(local_mbuf, uint64_t) -
>+					(uint64_t)local_mbuf;
>+			pkt = xsk_umem__get_data(umem->buffer, addr + offset);
>+			offset = offset << XSK_UNALIGNED_BUF_OFFSET_SHIFT;
>+			desc->addr = addr;
>+			desc->addr |= offset;
>+			rte_memcpy(pkt, rte_pktmbuf_mtod(mbuf, void *),
>+					desc->len);
>+			rte_pktmbuf_free(mbuf);
>+		}
>+
>+		tx_bytes += mbuf->pkt_len;
>+	}
>+
>+	xsk_ring_prod__submit(&txq->tx, nb_pkts - dropped);
>+
>+	kick_tx(txq);
>+#else
>+	void *addrs[ETH_AF_XDP_TX_BATCH_SIZE];
> 
> 	nb_pkts = RTE_MIN(nb_pkts, ETH_AF_XDP_TX_BATCH_SIZE);
> 
>@@ -333,6 +432,7 @@ eth_af_xdp_tx(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
> 
> 	if (xsk_ring_prod__reserve(&txq->tx, nb_pkts, &idx_tx) != nb_pkts) {
> 		kick_tx(txq);
>+		pull_umem_cq(umem, ETH_AF_XDP_TX_BATCH_SIZE);
> 		rte_ring_enqueue_bulk(umem->buf_ring, addrs, nb_pkts, NULL);
> 		return 0;
> 	}
>@@ -345,35 +445,23 @@ eth_af_xdp_tx(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
> 		mbuf = bufs[i];
> 		desc->len = mbuf->pkt_len;
> 
>-		/*
>-		 * We need to make sure the external mbuf address is within
>-		 * current port's umem memzone range
>-		 */
>-		if (pmd_zc && RTE_MBUF_HAS_EXTBUF(mbuf) &&
>-				in_umem_range(umem, (uint64_t)mbuf->buf_addr)) {
>-			desc->addr = (uint64_t)mbuf->buf_addr -
>-				umem->mz->addr_64;
>-			mbuf->buf_addr = xsk_umem__get_data(umem->mz->addr,
>-					(uint64_t)addrs[i]);
>-		} else {
>-			desc->addr = (uint64_t)addrs[i];
>-			pkt = xsk_umem__get_data(umem->mz->addr,
>-					desc->addr);
>-			rte_memcpy(pkt, rte_pktmbuf_mtod(mbuf, void *),
>-					desc->len);
>-		}
>+		desc->addr = (uint64_t)addrs[i];
>+		pkt = xsk_umem__get_data(umem->mz->addr,
>+					 desc->addr);
>+		rte_memcpy(pkt, rte_pktmbuf_mtod(mbuf, void *), desc->len);
> 		tx_bytes += mbuf->pkt_len;
>+		rte_pktmbuf_free(mbuf);
> 	}
> 
> 	xsk_ring_prod__submit(&txq->tx, nb_pkts);
> 
> 	kick_tx(txq);
>+	pull_umem_cq(umem, ETH_AF_XDP_TX_BATCH_SIZE);
>+#endif
> 
>-	txq->stats.tx_pkts += nb_pkts;
>+	txq->stats.tx_pkts += nb_pkts - dropped;
> 	txq->stats.tx_bytes += tx_bytes;
>-
>-	for (i = 0; i < nb_pkts; i++)
>-		rte_pktmbuf_free(bufs[i]);
>+	txq->stats.tx_dropped += dropped;
> 
> 	return nb_pkts;
> }
>@@ -446,6 +534,7 @@ eth_stats_get(struct rte_eth_dev *dev, struct rte_eth_stats *stats)
> 		stats->ipackets += stats->q_ipackets[i];
> 		stats->ibytes += stats->q_ibytes[i];
> 		stats->imissed += rxq->stats.rx_dropped;
>+		stats->oerrors += txq->stats.tx_dropped;
> 		ret = getsockopt(xsk_socket__fd(rxq->xsk), SOL_XDP,
> 				XDP_STATISTICS, &xdp_stats, &optlen);
> 		if (ret != 0) {
>@@ -492,11 +581,16 @@ remove_xdp_program(struct pmd_internals *internals)
> static void
> xdp_umem_destroy(struct xsk_umem_info *umem)
> {
>+#if defined(XDP_UMEM_UNALIGNED_CHUNK_FLAG)
>+	rte_mempool_free(umem->mb_pool);
>+	umem->mb_pool = NULL;
>+#else
> 	rte_memzone_free(umem->mz);
> 	umem->mz = NULL;
> 
> 	rte_ring_free(umem->buf_ring);
> 	umem->buf_ring = NULL;
>+#endif
> 
> 	rte_free(umem);
> 	umem = NULL;
>@@ -546,6 +640,55 @@ eth_link_update(struct rte_eth_dev *dev __rte_unused,
> 	return 0;
> }
> 
>+#if defined(XDP_UMEM_UNALIGNED_CHUNK_FLAG)
>+static inline uint64_t get_base_addr(struct rte_mempool *mp)
>+{
>+	struct rte_mempool_memhdr *memhdr;
>+
>+	memhdr = STAILQ_FIRST(&mp->mem_list);
>+	return (uint64_t)memhdr->addr & ~(getpagesize() - 1);
>+}
>+
>+static struct
>+xsk_umem_info *xdp_umem_configure(struct pmd_internals *internals __rte_unused,
>+				  struct pkt_rx_queue *rxq)
>+{
>+	struct xsk_umem_info *umem;
>+	int ret;
>+	struct xsk_umem_config usr_config = {
>+		.fill_size = ETH_AF_XDP_DFLT_NUM_DESCS,
>+		.comp_size = ETH_AF_XDP_DFLT_NUM_DESCS,
>+		.flags = XDP_UMEM_UNALIGNED_CHUNK_FLAG};
>+	void *base_addr = NULL;
>+	struct rte_mempool *mb_pool = rxq->mb_pool;
>+
>+	usr_config.frame_size = rte_pktmbuf_data_room_size(mb_pool) +
>+					ETH_AF_XDP_MBUF_OVERHEAD +
>+					mb_pool->private_data_size;
>+	usr_config.frame_headroom = ETH_AF_XDP_DATA_HEADROOM +
>+					mb_pool->private_data_size;
>+
>+	umem = rte_zmalloc_socket("umem", sizeof(*umem), 0, rte_socket_id());
>+	if (umem == NULL) {
>+		AF_XDP_LOG(ERR, "Failed to allocate umem info");
>+		return NULL;
>+	}
>+
>+	umem->mb_pool = mb_pool;
>+	base_addr = (void *)get_base_addr(mb_pool);
>+
>+	ret = xsk_umem__create(&umem->umem, base_addr,
>+			       mb_pool->populated_size * usr_config.frame_size,
>+			       &umem->fq, &umem->cq,
>+			       &usr_config);
>+
>+	if (ret) {
>+		AF_XDP_LOG(ERR, "Failed to create umem");
>+		goto err;
>+	}
>+	umem->buffer = base_addr;
>+
>+#else
> static struct
> xsk_umem_info *xdp_umem_configure(struct pmd_internals *internals,
> 				  struct pkt_rx_queue *rxq)
>@@ -606,6 +749,7 @@ xsk_umem_info *xdp_umem_configure(struct pmd_internals *internals,
> 	}
> 	umem->mz = mz;
> 
>+#endif
> 	return umem;
> 
> err:
>@@ -625,6 +769,7 @@ xsk_configure(struct pmd_internals *internals, struct pkt_rx_queue *rxq,
> 	rxq->umem = xdp_umem_configure(internals, rxq);
> 	if (rxq->umem == NULL)
> 		return -ENOMEM;
>+	txq->umem = rxq->umem;
> 
> 	cfg.rx_size = ring_size;
> 	cfg.tx_size = ring_size;
>@@ -669,7 +814,6 @@ eth_rx_queue_setup(struct rte_eth_dev *dev,
> 		   struct rte_mempool *mb_pool)
> {
> 	struct pmd_internals *internals = dev->data->dev_private;
>-	uint32_t buf_size, data_size;
> 	struct pkt_rx_queue *rxq;
> 	int ret;
> 
>@@ -677,6 +821,10 @@ eth_rx_queue_setup(struct rte_eth_dev *dev,
> 
> 	AF_XDP_LOG(INFO, "Set up rx queue, rx queue id: %d, xsk queue id: %d\n",
> 		   rx_queue_id, rxq->xsk_queue_idx);
>+
>+#ifndef XDP_UMEM_UNALIGNED_CHUNK_FLAG
>+	uint32_t buf_size, data_size;
>+
> 	/* Now get the space available for data in the mbuf */
> 	buf_size = rte_pktmbuf_data_room_size(mb_pool) -
> 		RTE_PKTMBUF_HEADROOM;
>@@ -688,6 +836,7 @@ eth_rx_queue_setup(struct rte_eth_dev *dev,
> 		ret = -ENOMEM;
> 		goto err;
> 	}
>+#endif
> 
> 	rxq->mb_pool = mb_pool;
> 
>@@ -700,8 +849,6 @@ eth_rx_queue_setup(struct rte_eth_dev *dev,
> 	rxq->fds[0].fd = xsk_socket__fd(rxq->xsk);
> 	rxq->fds[0].events = POLLIN;
> 
>-	rxq->umem->pmd_zc = internals->pmd_zc;
>-
> 	dev->data->rx_queues[rx_queue_id] = rxq;
> 	return 0;
> 
>@@ -877,7 +1024,7 @@ xdp_get_channels_info(const char *if_name, int *max_queues,
> 
> static int
> parse_parameters(struct rte_kvargs *kvlist, char *if_name, int *start_queue,
>-			int *queue_cnt, int *pmd_zc)
>+			int *queue_cnt)
> {
> 	int ret;
> 
>@@ -898,11 +1045,6 @@ parse_parameters(struct rte_kvargs *kvlist, char *if_name, int *start_queue,
> 		goto free_kvlist;
> 	}
> 
>-	ret = rte_kvargs_process(kvlist, ETH_AF_XDP_PMD_ZC_ARG,
>-				 &parse_integer_arg, pmd_zc);
>-	if (ret < 0)
>-		goto free_kvlist;
>-
> free_kvlist:
> 	rte_kvargs_free(kvlist);
> 	return ret;
>@@ -940,7 +1082,7 @@ get_iface_info(const char *if_name,
> 
> static struct rte_eth_dev *
> init_internals(struct rte_vdev_device *dev, const char *if_name,
>-			int start_queue_idx, int queue_cnt, int pmd_zc)
>+			int start_queue_idx, int queue_cnt)
> {
> 	const char *name = rte_vdev_device_name(dev);
> 	const unsigned int numa_node = dev->device.numa_node;
>@@ -955,7 +1097,6 @@ init_internals(struct rte_vdev_device *dev, const char *if_name,
> 
> 	internals->start_queue_idx = start_queue_idx;
> 	internals->queue_cnt = queue_cnt;
>-	internals->pmd_zc = pmd_zc;
> 	strlcpy(internals->if_name, if_name, IFNAMSIZ);
> 
> 	if (xdp_get_channels_info(if_name, &internals->max_queue_cnt,
>@@ -1011,8 +1152,9 @@ init_internals(struct rte_vdev_device *dev, const char *if_name,
> 	/* Let rte_eth_dev_close() release the port resources. */
> 	eth_dev->data->dev_flags |= RTE_ETH_DEV_CLOSE_REMOVE;
> 
>-	if (internals->pmd_zc)
>-		AF_XDP_LOG(INFO, "Zero copy between umem and mbuf enabled.\n");
>+#if defined(XDP_UMEM_UNALIGNED_CHUNK_FLAG)
>+	AF_XDP_LOG(INFO, "Zero copy between umem and mbuf enabled.\n");
>+#endif
> 
> 	return eth_dev;
> 
>@@ -1034,7 +1176,6 @@ rte_pmd_af_xdp_probe(struct rte_vdev_device *dev)
> 	int xsk_queue_cnt = ETH_AF_XDP_DFLT_QUEUE_COUNT;
> 	struct rte_eth_dev *eth_dev = NULL;
> 	const char *name;
>-	int pmd_zc = 0;
> 
> 	AF_XDP_LOG(INFO, "Initializing pmd_af_xdp for %s\n",
> 		rte_vdev_device_name(dev));
>@@ -1062,7 +1203,7 @@ rte_pmd_af_xdp_probe(struct rte_vdev_device *dev)
> 		dev->device.numa_node = rte_socket_id();
> 
> 	if (parse_parameters(kvlist, if_name, &xsk_start_queue_idx,
>-			     &xsk_queue_cnt, &pmd_zc) < 0) {
>+			     &xsk_queue_cnt) < 0) {
> 		AF_XDP_LOG(ERR, "Invalid kvargs value\n");
> 		return -EINVAL;
> 	}
>@@ -1073,7 +1214,7 @@ rte_pmd_af_xdp_probe(struct rte_vdev_device *dev)
> 	}
> 
> 	eth_dev = init_internals(dev, if_name, xsk_start_queue_idx,
>-					xsk_queue_cnt, pmd_zc);
>+					xsk_queue_cnt);
> 	if (eth_dev == NULL) {
> 		AF_XDP_LOG(ERR, "Failed to init internals\n");
> 		return -1;
>@@ -1116,8 +1257,7 @@ RTE_PMD_REGISTER_VDEV(net_af_xdp, pmd_af_xdp_drv);
> RTE_PMD_REGISTER_PARAM_STRING(net_af_xdp,
> 			      "iface=<string> "
> 			      "start_queue=<int> "
>-			      "queue_count=<int> "
>-			      "pmd_zero_copy=<0|1>");
>+			      "queue_count=<int>");
> 
> RTE_INIT(af_xdp_init_log)
> {
>-- 
>2.17.1
>