[v2] net/af_xdp: enable support for unaligned umem chunks

  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>
---
v2:
* Updated af_xdp.rst with kernel dependency info
* Fixed case on rx where mbuf alloc fails

 doc/guides/nics/af_xdp.rst             |   2 +-
 doc/guides/rel_notes/release_19_11.rst |   9 +
 drivers/net/af_xdp/rte_eth_af_xdp.c    | 306 ++++++++++++++++++-------
 3 files changed, 234 insertions(+), 83 deletions(-)
  

Hi, Ciara

On 09/05, 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>
>---
>v2:
>* Updated af_xdp.rst with kernel dependency info
>* Fixed case on rx where mbuf alloc fails
>
> doc/guides/nics/af_xdp.rst             |   2 +-
> doc/guides/rel_notes/release_19_11.rst |   9 +
> drivers/net/af_xdp/rte_eth_af_xdp.c    | 306 ++++++++++++++++++-------
> 3 files changed, 234 insertions(+), 83 deletions(-)
>
>diff --git a/doc/guides/nics/af_xdp.rst b/doc/guides/nics/af_xdp.rst
>index ec46f08f0..b434b25df 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
> -------------
>@@ -48,6 +47,7 @@ This is a Linux-specific PMD, thus the following prerequisites apply:
>    <kernel src tree>/tools/lib/bpf;
> *  A Kernel bound interface to attach to;
> *  For need_wakeup feature, it requires kernel version later than v5.3-rc1;
>+*  For PMD zero copy, it requires kernel version later than v5.4-rc1;
> 
> Set up an af_xdp interface
> -----------------------------
>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.
>+
> 
> 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..e1089e40c 100644
>--- a/drivers/net/af_xdp/rte_eth_af_xdp.c
>+++ b/drivers/net/af_xdp/rte_eth_af_xdp.c
>@@ -58,7 +58,13 @@ static int af_xdp_logtype;
> 
> #define ETH_AF_XDP_FRAME_SIZE		2048
> #define ETH_AF_XDP_NUM_BUFFERS		4096
>+#ifdef XDP_UMEM_UNALIGNED_CHUNK_FLAG
>+#define ETH_AF_XDP_MBUF_OVERHEAD	128 /* sizeof(struct rte_mbuf) */
>+#define ETH_AF_XDP_DATA_HEADROOM \
>+	(ETH_AF_XDP_MBUF_OVERHEAD + RTE_PKTMBUF_HEADROOM)
>+#else
> #define ETH_AF_XDP_DATA_HEADROOM	0
>+#endif
> #define ETH_AF_XDP_DFLT_NUM_DESCS	XSK_RING_CONS__DEFAULT_NUM_DESCS
> #define ETH_AF_XDP_DFLT_START_QUEUE_IDX	0
> #define ETH_AF_XDP_DFLT_QUEUE_COUNT	1
>@@ -73,7 +79,8 @@ struct xsk_umem_info {
> 	struct xsk_umem *umem;
> 	struct rte_ring *buf_ring;
> 	const struct rte_memzone *mz;
>-	int pmd_zc;
>+	struct rte_mempool *mb_pool;
>+	void *buffer;
> };
> 
> struct rx_stats {
>@@ -98,10 +105,12 @@ struct pkt_rx_queue {
> struct tx_stats {
> 	uint64_t tx_pkts;
> 	uint64_t tx_bytes;
>+	uint64_t tx_dropped;
> };
> 
> struct pkt_tx_queue {
> 	struct xsk_ring_prod tx;
>+	struct xsk_umem_info *umem;
> 
> 	struct tx_stats stats;
> 
>@@ -117,7 +126,6 @@ struct pmd_internals {
> 	int max_queue_cnt;
> 	int combined_queue_cnt;
> 
>-	int pmd_zc;
> 	struct rte_ether_addr eth_addr;
> 
> 	struct pkt_rx_queue *rx_queues;
>@@ -127,13 +135,11 @@ struct pmd_internals {
> #define ETH_AF_XDP_IFACE_ARG			"iface"
> #define ETH_AF_XDP_START_QUEUE_ARG		"start_queue"
> #define ETH_AF_XDP_QUEUE_COUNT_ARG		"queue_count"
>-#define ETH_AF_XDP_PMD_ZC_ARG			"pmd_zero_copy"
> 
> static const char * const valid_arguments[] = {
> 	ETH_AF_XDP_IFACE_ARG,
> 	ETH_AF_XDP_START_QUEUE_ARG,
> 	ETH_AF_XDP_QUEUE_COUNT_ARG,
>-	ETH_AF_XDP_PMD_ZC_ARG,
> 	NULL
> };
> 
>@@ -148,9 +154,32 @@ static inline int
> 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)) {
>+			reserve_size = i;

If this case happens, the new reserve_sizei (n) will be less than its original value (N),
so we would end up with reserve N slots, but only submit n slots later, then we
would get an wrong number of available slots later.
My previous way of solving this inconsistent issue is to alloc a bulk of mbuf
at first, if alloc fails, directly return before reserving any slots, in this
way we can make sure the reserve/submit consistent, there should also be some
performance benefit from the bulk allocation.

>+			break;
>+		}
>+
>+		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 +200,13 @@ 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 +215,53 @@ 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)

What about we extract out some functions to make rx more readable? Some thing like:

#if defined(XDP_UMEM_UNALIGNED_CHUNK_FLAG)
	af_xdp_rx_zc()
#else
	af_xdp_rx_cp()
#endif

I think this also applies for tx.

Otherwise, people will easily get lost in multiple #if/#else/#endif, since
we have have XDP_USE_NEED_WAKEUP here.

>+
>+	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);

Since both zc and cp mode would call reserve_fill_queue, how about just move it
to the common part of rx to avoid duplication?

>+#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 +286,14 @@ 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 +310,7 @@ 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 +327,14 @@ 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 +343,7 @@ 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 +358,70 @@ 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;
What about 

	desc->addr = addr | offset; 

>+		} else {
>+			struct rte_mbuf *local_mbuf =
>+					rte_pktmbuf_alloc(umem->mb_pool);
>+			void *pkt;
>+
>+			if (!local_mbuf) {

Better to user style like 'local_mbuf == NULL' to follow the convention of this
file, and this is also preferred according to dpdk's coding style.

>+				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;

			desc->addr = 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);

Similar inconsistent reserve/submit may happen in tx.


Thanks,
Xiaolong
>+
>+	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 +434,7 @@ 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 +447,23 @@ 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 +536,7 @@ 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 +583,16 @@ 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 +642,55 @@ 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 +751,7 @@ xsk_umem_info *xdp_umem_configure(struct pmd_internals *internals,
> 	}
> 	umem->mz = mz;
> 
>+#endif
> 	return umem;
> 
> err:
>@@ -625,6 +771,7 @@ 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 +816,6 @@ 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 +823,10 @@ 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 +838,7 @@ eth_rx_queue_setup(struct rte_eth_dev *dev,
> 		ret = -ENOMEM;
> 		goto err;
> 	}
>+#endif
> 
> 	rxq->mb_pool = mb_pool;
> 
>@@ -700,8 +851,6 @@ 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 +1026,7 @@ 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 +1047,6 @@ 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 +1084,7 @@ 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 +1099,6 @@ 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 +1154,9 @@ 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 +1178,6 @@ 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 +1205,7 @@ 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 +1216,7 @@ 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 +1259,7 @@ 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
>