1 files changed, 747 insertions, 0 deletions

diff --git a/src/dpdk_lib18/librte_pmd_virtio/virtio_rxtx.c b/src/dpdk_lib18/librte_pmd_virtio/virtio_rxtx.c
new file mode 100755
index 00000000..c013f976
--- /dev/null
+++ b/src/dpdk_lib18/librte_pmd_virtio/virtio_rxtx.c
@@ -0,0 +1,747 @@
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
+ *   All rights reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+
+#include <rte_cycles.h>
+#include <rte_memory.h>
+#include <rte_memzone.h>
+#include <rte_branch_prediction.h>
+#include <rte_mempool.h>
+#include <rte_malloc.h>
+#include <rte_mbuf.h>
+#include <rte_ether.h>
+#include <rte_ethdev.h>
+#include <rte_prefetch.h>
+#include <rte_string_fns.h>
+#include <rte_errno.h>
+
+#include "virtio_logs.h"
+#include "virtio_ethdev.h"
+#include "virtqueue.h"
+
+#ifdef RTE_LIBRTE_VIRTIO_DEBUG_DUMP
+#define VIRTIO_DUMP_PACKET(m, len) rte_pktmbuf_dump(stdout, m, len)
+#else
+#define  VIRTIO_DUMP_PACKET(m, len) do { } while (0)
+#endif
+
+static void
+vq_ring_free_chain(struct virtqueue *vq, uint16_t desc_idx)
+{
+	struct vring_desc *dp, *dp_tail;
+	struct vq_desc_extra *dxp;
+	uint16_t desc_idx_last = desc_idx;
+
+	dp  = &vq->vq_ring.desc[desc_idx];
+	dxp = &vq->vq_descx[desc_idx];
+	vq->vq_free_cnt = (uint16_t)(vq->vq_free_cnt + dxp->ndescs);
+	if ((dp->flags & VRING_DESC_F_INDIRECT) == 0) {
+		while (dp->flags & VRING_DESC_F_NEXT) {
+			desc_idx_last = dp->next;
+			dp = &vq->vq_ring.desc[dp->next];
+		}
+	}
+	dxp->ndescs = 0;
+
+	/*
+	 * We must append the existing free chain, if any, to the end of
+	 * newly freed chain. If the virtqueue was completely used, then
+	 * head would be VQ_RING_DESC_CHAIN_END (ASSERTed above).
+	 */
+	if (vq->vq_desc_tail_idx == VQ_RING_DESC_CHAIN_END) {
+		vq->vq_desc_head_idx = desc_idx;
+	} else {
+		dp_tail = &vq->vq_ring.desc[vq->vq_desc_tail_idx];
+		dp_tail->next = desc_idx;
+	}
+
+	vq->vq_desc_tail_idx = desc_idx_last;
+	dp->next = VQ_RING_DESC_CHAIN_END;
+}
+
+static uint16_t
+virtqueue_dequeue_burst_rx(struct virtqueue *vq, struct rte_mbuf **rx_pkts,
+			   uint32_t *len, uint16_t num)
+{
+	struct vring_used_elem *uep;
+	struct rte_mbuf *cookie;
+	uint16_t used_idx, desc_idx;
+	uint16_t i;
+
+	/*  Caller does the check */
+	for (i = 0; i < num ; i++) {
+		used_idx = (uint16_t)(vq->vq_used_cons_idx & (vq->vq_nentries - 1));
+		uep = &vq->vq_ring.used->ring[used_idx];
+		desc_idx = (uint16_t) uep->id;
+		len[i] = uep->len;
+		cookie = (struct rte_mbuf *)vq->vq_descx[desc_idx].cookie;
+
+		if (unlikely(cookie == NULL)) {
+			PMD_DRV_LOG(ERR, "vring descriptor with no mbuf cookie at %u\n",
+				vq->vq_used_cons_idx);
+			break;
+		}
+
+		rte_prefetch0(cookie);
+		rte_packet_prefetch(rte_pktmbuf_mtod(cookie, void *));
+		rx_pkts[i]  = cookie;
+		vq->vq_used_cons_idx++;
+		vq_ring_free_chain(vq, desc_idx);
+		vq->vq_descx[desc_idx].cookie = NULL;
+	}
+
+	return i;
+}
+
+static void
+virtqueue_dequeue_pkt_tx(struct virtqueue *vq)
+{
+	struct vring_used_elem *uep;
+	uint16_t used_idx, desc_idx;
+
+	used_idx = (uint16_t)(vq->vq_used_cons_idx & (vq->vq_nentries - 1));
+	uep = &vq->vq_ring.used->ring[used_idx];
+	desc_idx = (uint16_t) uep->id;
+	vq->vq_used_cons_idx++;
+	vq_ring_free_chain(vq, desc_idx);
+}
+
+
+static inline int
+virtqueue_enqueue_recv_refill(struct virtqueue *vq, struct rte_mbuf *cookie)
+{
+	struct vq_desc_extra *dxp;
+	struct virtio_hw *hw = vq->hw;
+	struct vring_desc *start_dp;
+	uint16_t needed = 1;
+	uint16_t head_idx, idx;
+
+	if (unlikely(vq->vq_free_cnt == 0))
+		return -ENOSPC;
+	if (unlikely(vq->vq_free_cnt < needed))
+		return -EMSGSIZE;
+
+	head_idx = vq->vq_desc_head_idx;
+	if (unlikely(head_idx >= vq->vq_nentries))
+		return -EFAULT;
+
+	idx = head_idx;
+	dxp = &vq->vq_descx[idx];
+	dxp->cookie = (void *)cookie;
+	dxp->ndescs = needed;
+
+	start_dp = vq->vq_ring.desc;
+	start_dp[idx].addr =
+		(uint64_t)(cookie->buf_physaddr + RTE_PKTMBUF_HEADROOM
+		- hw->vtnet_hdr_size);
+	start_dp[idx].len =
+		cookie->buf_len - RTE_PKTMBUF_HEADROOM + hw->vtnet_hdr_size;
+	start_dp[idx].flags =  VRING_DESC_F_WRITE;
+	idx = start_dp[idx].next;
+	vq->vq_desc_head_idx = idx;
+	if (vq->vq_desc_head_idx == VQ_RING_DESC_CHAIN_END)
+		vq->vq_desc_tail_idx = idx;
+	vq->vq_free_cnt = (uint16_t)(vq->vq_free_cnt - needed);
+	vq_update_avail_ring(vq, head_idx);
+
+	return 0;
+}
+
+static int
+virtqueue_enqueue_xmit(struct virtqueue *txvq, struct rte_mbuf *cookie)
+{
+	struct vq_desc_extra *dxp;
+	struct vring_desc *start_dp;
+	uint16_t seg_num = cookie->nb_segs;
+	uint16_t needed = 1 + seg_num;
+	uint16_t head_idx, idx;
+	uint16_t head_size = txvq->hw->vtnet_hdr_size;
+
+	if (unlikely(txvq->vq_free_cnt == 0))
+		return -ENOSPC;
+	if (unlikely(txvq->vq_free_cnt < needed))
+		return -EMSGSIZE;
+	head_idx = txvq->vq_desc_head_idx;
+	if (unlikely(head_idx >= txvq->vq_nentries))
+		return -EFAULT;
+
+	idx = head_idx;
+	dxp = &txvq->vq_descx[idx];
+	if (dxp->cookie != NULL)
+		rte_pktmbuf_free(dxp->cookie);
+	dxp->cookie = (void *)cookie;
+	dxp->ndescs = needed;
+
+	start_dp = txvq->vq_ring.desc;
+	start_dp[idx].addr =
+		txvq->virtio_net_hdr_mem + idx * head_size;
+	start_dp[idx].len = (uint32_t)head_size;
+	start_dp[idx].flags = VRING_DESC_F_NEXT;
+
+	for (; ((seg_num > 0) && (cookie != NULL)); seg_num--) {
+		idx = start_dp[idx].next;
+		start_dp[idx].addr  = RTE_MBUF_DATA_DMA_ADDR(cookie);
+		start_dp[idx].len   = cookie->data_len;
+		start_dp[idx].flags = VRING_DESC_F_NEXT;
+		cookie = cookie->next;
+	}
+
+	start_dp[idx].flags &= ~VRING_DESC_F_NEXT;
+	idx = start_dp[idx].next;
+	txvq->vq_desc_head_idx = idx;
+	if (txvq->vq_desc_head_idx == VQ_RING_DESC_CHAIN_END)
+		txvq->vq_desc_tail_idx = idx;
+	txvq->vq_free_cnt = (uint16_t)(txvq->vq_free_cnt - needed);
+	vq_update_avail_ring(txvq, head_idx);
+
+	return 0;
+}
+
+static inline struct rte_mbuf *
+rte_rxmbuf_alloc(struct rte_mempool *mp)
+{
+	struct rte_mbuf *m;
+
+	m = __rte_mbuf_raw_alloc(mp);
+	__rte_mbuf_sanity_check_raw(m, 0);
+
+	return m;
+}
+
+static void
+virtio_dev_vring_start(struct virtqueue *vq, int queue_type)
+{
+	struct rte_mbuf *m;
+	int i, nbufs, error, size = vq->vq_nentries;
+	struct vring *vr = &vq->vq_ring;
+	uint8_t *ring_mem = vq->vq_ring_virt_mem;
+
+	PMD_INIT_FUNC_TRACE();
+
+	/*
+	 * Reinitialise since virtio port might have been stopped and restarted
+	 */
+	memset(vq->vq_ring_virt_mem, 0, vq->vq_ring_size);
+	vring_init(vr, size, ring_mem, vq->vq_alignment);
+	vq->vq_used_cons_idx = 0;
+	vq->vq_desc_head_idx = 0;
+	vq->vq_avail_idx = 0;
+	vq->vq_desc_tail_idx = (uint16_t)(vq->vq_nentries - 1);
+	vq->vq_free_cnt = vq->vq_nentries;
+	memset(vq->vq_descx, 0, sizeof(struct vq_desc_extra) * vq->vq_nentries);
+
+	/* Chain all the descriptors in the ring with an END */
+	for (i = 0; i < size - 1; i++)
+		vr->desc[i].next = (uint16_t)(i + 1);
+	vr->desc[i].next = VQ_RING_DESC_CHAIN_END;
+
+	/*
+	 * Disable device(host) interrupting guest
+	 */
+	virtqueue_disable_intr(vq);
+
+	/* Only rx virtqueue needs mbufs to be allocated at initialization */
+	if (queue_type == VTNET_RQ) {
+		if (vq->mpool == NULL)
+			rte_exit(EXIT_FAILURE,
+			"Cannot allocate initial mbufs for rx virtqueue");
+
+		/* Allocate blank mbufs for the each rx descriptor */
+		nbufs = 0;
+		error = ENOSPC;
+		while (!virtqueue_full(vq)) {
+			m = rte_rxmbuf_alloc(vq->mpool);
+			if (m == NULL)
+				break;
+
+			/******************************************
+			*         Enqueue allocated buffers        *
+			*******************************************/
+			error = virtqueue_enqueue_recv_refill(vq, m);
+
+			if (error) {
+				rte_pktmbuf_free(m);
+				break;
+			}
+			nbufs++;
+		}
+
+		vq_update_avail_idx(vq);
+
+		PMD_INIT_LOG(DEBUG, "Allocated %d bufs", nbufs);
+
+		VIRTIO_WRITE_REG_2(vq->hw, VIRTIO_PCI_QUEUE_SEL,
+			vq->vq_queue_index);
+		VIRTIO_WRITE_REG_4(vq->hw, VIRTIO_PCI_QUEUE_PFN,
+			vq->mz->phys_addr >> VIRTIO_PCI_QUEUE_ADDR_SHIFT);
+	} else if (queue_type == VTNET_TQ) {
+		VIRTIO_WRITE_REG_2(vq->hw, VIRTIO_PCI_QUEUE_SEL,
+			vq->vq_queue_index);
+		VIRTIO_WRITE_REG_4(vq->hw, VIRTIO_PCI_QUEUE_PFN,
+			vq->mz->phys_addr >> VIRTIO_PCI_QUEUE_ADDR_SHIFT);
+	} else {
+		VIRTIO_WRITE_REG_2(vq->hw, VIRTIO_PCI_QUEUE_SEL,
+			vq->vq_queue_index);
+		VIRTIO_WRITE_REG_4(vq->hw, VIRTIO_PCI_QUEUE_PFN,
+			vq->mz->phys_addr >> VIRTIO_PCI_QUEUE_ADDR_SHIFT);
+	}
+}
+
+void
+virtio_dev_cq_start(struct rte_eth_dev *dev)
+{
+	struct virtio_hw *hw
+		= VIRTIO_DEV_PRIVATE_TO_HW(dev->data->dev_private);
+
+	if (hw->cvq) {
+		virtio_dev_vring_start(hw->cvq, VTNET_CQ);
+		VIRTQUEUE_DUMP((struct virtqueue *)hw->cvq);
+	}
+}
+
+void
+virtio_dev_rxtx_start(struct rte_eth_dev *dev)
+{
+	/*
+	 * Start receive and transmit vrings
+	 * -	Setup vring structure for all queues
+	 * -	Initialize descriptor for the rx vring
+	 * -	Allocate blank mbufs for the each rx descriptor
+	 *
+	 */
+	int i;
+
+	PMD_INIT_FUNC_TRACE();
+
+	/* Start rx vring. */
+	for (i = 0; i < dev->data->nb_rx_queues; i++) {
+		virtio_dev_vring_start(dev->data->rx_queues[i], VTNET_RQ);
+		VIRTQUEUE_DUMP((struct virtqueue *)dev->data->rx_queues[i]);
+	}
+
+	/* Start tx vring. */
+	for (i = 0; i < dev->data->nb_tx_queues; i++) {
+		virtio_dev_vring_start(dev->data->tx_queues[i], VTNET_TQ);
+		VIRTQUEUE_DUMP((struct virtqueue *)dev->data->tx_queues[i]);
+	}
+}
+
+int
+virtio_dev_rx_queue_setup(struct rte_eth_dev *dev,
+			uint16_t queue_idx,
+			uint16_t nb_desc,
+			unsigned int socket_id,
+			__rte_unused const struct rte_eth_rxconf *rx_conf,
+			struct rte_mempool *mp)
+{
+	uint8_t vtpci_queue_idx = 2 * queue_idx + VTNET_SQ_RQ_QUEUE_IDX;
+	struct virtqueue *vq;
+	int ret;
+
+	PMD_INIT_FUNC_TRACE();
+	ret = virtio_dev_queue_setup(dev, VTNET_RQ, queue_idx, vtpci_queue_idx,
+			nb_desc, socket_id, &vq);
+	if (ret < 0) {
+		PMD_INIT_LOG(ERR, "tvq initialization failed");
+		return ret;
+	}
+
+	/* Create mempool for rx mbuf allocation */
+	vq->mpool = mp;
+
+	dev->data->rx_queues[queue_idx] = vq;
+	return 0;
+}
+
+/*
+ * struct rte_eth_dev *dev: Used to update dev
+ * uint16_t nb_desc: Defaults to values read from config space
+ * unsigned int socket_id: Used to allocate memzone
+ * const struct rte_eth_txconf *tx_conf: Used to setup tx engine
+ * uint16_t queue_idx: Just used as an index in dev txq list
+ */
+int
+virtio_dev_tx_queue_setup(struct rte_eth_dev *dev,
+			uint16_t queue_idx,
+			uint16_t nb_desc,
+			unsigned int socket_id,
+			const struct rte_eth_txconf *tx_conf)
+{
+	uint8_t vtpci_queue_idx = 2 * queue_idx + VTNET_SQ_TQ_QUEUE_IDX;
+	struct virtqueue *vq;
+	int ret;
+
+	PMD_INIT_FUNC_TRACE();
+
+	if ((tx_conf->txq_flags & ETH_TXQ_FLAGS_NOOFFLOADS)
+	    != ETH_TXQ_FLAGS_NOOFFLOADS) {
+		PMD_INIT_LOG(ERR, "TX checksum offload not supported\n");
+		return -EINVAL;
+	}
+
+	ret = virtio_dev_queue_setup(dev, VTNET_TQ, queue_idx, vtpci_queue_idx,
+			nb_desc, socket_id, &vq);
+	if (ret < 0) {
+		PMD_INIT_LOG(ERR, "rvq initialization failed");
+		return ret;
+	}
+
+	dev->data->tx_queues[queue_idx] = vq;
+	return 0;
+}
+
+static void
+virtio_discard_rxbuf(struct virtqueue *vq, struct rte_mbuf *m)
+{
+	int error;
+	/*
+	 * Requeue the discarded mbuf. This should always be
+	 * successful since it was just dequeued.
+	 */
+	error = virtqueue_enqueue_recv_refill(vq, m);
+	if (unlikely(error)) {
+		RTE_LOG(ERR, PMD, "cannot requeue discarded mbuf");
+		rte_pktmbuf_free(m);
+	}
+}
+
+#define VIRTIO_MBUF_BURST_SZ 64
+#define DESC_PER_CACHELINE (RTE_CACHE_LINE_SIZE / sizeof(struct vring_desc))
+uint16_t
+virtio_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts, uint16_t nb_pkts)
+{
+	struct virtqueue *rxvq = rx_queue;
+	struct rte_mbuf *rxm, *new_mbuf;
+	uint16_t nb_used, num, nb_rx = 0;
+	uint32_t len[VIRTIO_MBUF_BURST_SZ];
+	struct rte_mbuf *rcv_pkts[VIRTIO_MBUF_BURST_SZ];
+	int error;
+	uint32_t i, nb_enqueued = 0;
+	const uint32_t hdr_size = sizeof(struct virtio_net_hdr);
+
+	nb_used = VIRTQUEUE_NUSED(rxvq);
+
+	rmb();
+
+	num = (uint16_t)(likely(nb_used <= nb_pkts) ? nb_used : nb_pkts);
+	num = (uint16_t)(likely(num <= VIRTIO_MBUF_BURST_SZ) ? num : VIRTIO_MBUF_BURST_SZ);
+	if (likely(num > DESC_PER_CACHELINE))
+		num = num - ((rxvq->vq_used_cons_idx + num) % DESC_PER_CACHELINE);
+
+	if (num == 0)
+		return 0;
+
+	num = virtqueue_dequeue_burst_rx(rxvq, rcv_pkts, len, num);
+	PMD_RX_LOG(DEBUG, "used:%d dequeue:%d", nb_used, num);
+	for (i = 0; i < num ; i++) {
+		rxm = rcv_pkts[i];
+
+		PMD_RX_LOG(DEBUG, "packet len:%d", len[i]);
+
+		if (unlikely(len[i] < hdr_size + ETHER_HDR_LEN)) {
+			PMD_RX_LOG(ERR, "Packet drop");
+			nb_enqueued++;
+			virtio_discard_rxbuf(rxvq, rxm);
+			rxvq->errors++;
+			continue;
+		}
+
+		rxm->port = rxvq->port_id;
+		rxm->data_off = RTE_PKTMBUF_HEADROOM;
+
+		rxm->nb_segs = 1;
+		rxm->next = NULL;
+		rxm->pkt_len = (uint32_t)(len[i] - hdr_size);
+		rxm->data_len = (uint16_t)(len[i] - hdr_size);
+
+		VIRTIO_DUMP_PACKET(rxm, rxm->data_len);
+
+		rx_pkts[nb_rx++] = rxm;
+		rxvq->bytes += rx_pkts[nb_rx - 1]->pkt_len;
+	}
+
+	rxvq->packets += nb_rx;
+
+	/* Allocate new mbuf for the used descriptor */
+	error = ENOSPC;
+	while (likely(!virtqueue_full(rxvq))) {
+		new_mbuf = rte_rxmbuf_alloc(rxvq->mpool);
+		if (unlikely(new_mbuf == NULL)) {
+			struct rte_eth_dev *dev
+				= &rte_eth_devices[rxvq->port_id];
+			dev->data->rx_mbuf_alloc_failed++;
+			break;
+		}
+		error = virtqueue_enqueue_recv_refill(rxvq, new_mbuf);
+		if (unlikely(error)) {
+			rte_pktmbuf_free(new_mbuf);
+			break;
+		}
+		nb_enqueued++;
+	}
+
+	if (likely(nb_enqueued)) {
+		if (unlikely(virtqueue_kick_prepare(rxvq))) {
+			virtqueue_notify(rxvq);
+			PMD_RX_LOG(DEBUG, "Notified\n");
+		}
+	}
+
+	vq_update_avail_idx(rxvq);
+
+	return nb_rx;
+}
+
+uint16_t
+virtio_recv_mergeable_pkts(void *rx_queue,
+			struct rte_mbuf **rx_pkts,
+			uint16_t nb_pkts)
+{
+	struct virtqueue *rxvq = rx_queue;
+	struct rte_mbuf *rxm, *new_mbuf;
+	uint16_t nb_used, num, nb_rx = 0;
+	uint32_t len[VIRTIO_MBUF_BURST_SZ];
+	struct rte_mbuf *rcv_pkts[VIRTIO_MBUF_BURST_SZ];
+	struct rte_mbuf *prev;
+	int error;
+	uint32_t i = 0, nb_enqueued = 0;
+	uint32_t seg_num = 0;
+	uint16_t extra_idx = 0;
+	uint32_t seg_res = 0;
+	const uint32_t hdr_size = sizeof(struct virtio_net_hdr_mrg_rxbuf);
+
+	nb_used = VIRTQUEUE_NUSED(rxvq);
+
+	rmb();
+
+	if (nb_used == 0)
+		return 0;
+
+	PMD_RX_LOG(DEBUG, "used:%d\n", nb_used);
+
+	while (i < nb_used) {
+		struct virtio_net_hdr_mrg_rxbuf *header;
+
+		if (nb_rx == nb_pkts)
+			break;
+
+		num = virtqueue_dequeue_burst_rx(rxvq, rcv_pkts, len, 1);
+		if (num != 1)
+			continue;
+
+		i++;
+
+		PMD_RX_LOG(DEBUG, "dequeue:%d\n", num);
+		PMD_RX_LOG(DEBUG, "packet len:%d\n", len[0]);
+
+		rxm = rcv_pkts[0];
+
+		if (unlikely(len[0] < hdr_size + ETHER_HDR_LEN)) {
+			PMD_RX_LOG(ERR, "Packet drop\n");
+			nb_enqueued++;
+			virtio_discard_rxbuf(rxvq, rxm);
+			rxvq->errors++;
+			continue;
+		}
+
+		header = (struct virtio_net_hdr_mrg_rxbuf *)((char *)rxm->buf_addr +
+			RTE_PKTMBUF_HEADROOM - hdr_size);
+		seg_num = header->num_buffers;
+
+		if (seg_num == 0)
+			seg_num = 1;
+
+		rxm->data_off = RTE_PKTMBUF_HEADROOM;
+		rxm->nb_segs = seg_num;
+		rxm->next = NULL;
+		rxm->pkt_len = (uint32_t)(len[0] - hdr_size);
+		rxm->data_len = (uint16_t)(len[0] - hdr_size);
+
+		rxm->port = rxvq->port_id;
+		rx_pkts[nb_rx] = rxm;
+		prev = rxm;
+
+		seg_res = seg_num - 1;
+
+		while (seg_res != 0) {
+			/*
+			 * Get extra segments for current uncompleted packet.
+			 */
+			uint32_t  rcv_cnt =
+				RTE_MIN(seg_res, RTE_DIM(rcv_pkts));
+			if (likely(VIRTQUEUE_NUSED(rxvq) >= rcv_cnt)) {
+				uint32_t rx_num =
+					virtqueue_dequeue_burst_rx(rxvq,
+					rcv_pkts, len, rcv_cnt);
+				i += rx_num;
+				rcv_cnt = rx_num;
+			} else {
+				PMD_RX_LOG(ERR,
+					"No enough segments for packet.\n");
+				nb_enqueued++;
+				virtio_discard_rxbuf(rxvq, rxm);
+				rxvq->errors++;
+				break;
+			}
+
+			extra_idx = 0;
+
+			while (extra_idx < rcv_cnt) {
+				rxm = rcv_pkts[extra_idx];
+
+				rxm->data_off = RTE_PKTMBUF_HEADROOM - hdr_size;
+				rxm->next = NULL;
+				rxm->pkt_len = (uint32_t)(len[extra_idx]);
+				rxm->data_len = (uint16_t)(len[extra_idx]);
+
+				if (prev)
+					prev->next = rxm;
+
+				prev = rxm;
+				rx_pkts[nb_rx]->pkt_len += rxm->pkt_len;
+				extra_idx++;
+			};
+			seg_res -= rcv_cnt;
+		}
+
+		VIRTIO_DUMP_PACKET(rx_pkts[nb_rx],
+			rx_pkts[nb_rx]->data_len);
+
+		rxvq->bytes += rx_pkts[nb_rx]->pkt_len;
+		nb_rx++;
+	}
+
+	rxvq->packets += nb_rx;
+
+	/* Allocate new mbuf for the used descriptor */
+	error = ENOSPC;
+	while (likely(!virtqueue_full(rxvq))) {
+		new_mbuf = rte_rxmbuf_alloc(rxvq->mpool);
+		if (unlikely(new_mbuf == NULL)) {
+			struct rte_eth_dev *dev
+				= &rte_eth_devices[rxvq->port_id];
+			dev->data->rx_mbuf_alloc_failed++;
+			break;
+		}
+		error = virtqueue_enqueue_recv_refill(rxvq, new_mbuf);
+		if (unlikely(error)) {
+			rte_pktmbuf_free(new_mbuf);
+			break;
+		}
+		nb_enqueued++;
+	}
+
+	if (likely(nb_enqueued)) {
+		if (unlikely(virtqueue_kick_prepare(rxvq))) {
+			virtqueue_notify(rxvq);
+			PMD_RX_LOG(DEBUG, "Notified");
+		}
+	}
+
+	vq_update_avail_idx(rxvq);
+
+	return nb_rx;
+}
+
+uint16_t
+virtio_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
+{
+	struct virtqueue *txvq = tx_queue;
+	struct rte_mbuf *txm;
+	uint16_t nb_used, nb_tx, num;
+	int error;
+
+	nb_tx = 0;
+
+	if (unlikely(nb_pkts < 1))
+		return nb_pkts;
+
+	PMD_TX_LOG(DEBUG, "%d packets to xmit", nb_pkts);
+	nb_used = VIRTQUEUE_NUSED(txvq);
+
+	rmb();
+
+	num = (uint16_t)(likely(nb_used < VIRTIO_MBUF_BURST_SZ) ? nb_used : VIRTIO_MBUF_BURST_SZ);
+
+	while (nb_tx < nb_pkts) {
+		/* Need one more descriptor for virtio header. */
+		int need = tx_pkts[nb_tx]->nb_segs - txvq->vq_free_cnt + 1;
+		int deq_cnt = RTE_MIN(need, (int)num);
+
+		num -= (deq_cnt > 0) ? deq_cnt : 0;
+		while (deq_cnt > 0) {
+			virtqueue_dequeue_pkt_tx(txvq);
+			deq_cnt--;
+		}
+
+		need = (int)tx_pkts[nb_tx]->nb_segs - txvq->vq_free_cnt + 1;
+		/*
+		 * Zero or negative value indicates it has enough free
+		 * descriptors to use for transmitting.
+		 */
+		if (likely(need <= 0)) {
+			txm = tx_pkts[nb_tx];
+			/* Enqueue Packet buffers */
+			error = virtqueue_enqueue_xmit(txvq, txm);
+			if (unlikely(error)) {
+				if (error == ENOSPC)
+					PMD_TX_LOG(ERR, "virtqueue_enqueue Free count = 0");
+				else if (error == EMSGSIZE)
+					PMD_TX_LOG(ERR, "virtqueue_enqueue Free count < 1");
+				else
+					PMD_TX_LOG(ERR, "virtqueue_enqueue error: %d", error);
+				break;
+			}
+			nb_tx++;
+			txvq->bytes += txm->pkt_len;
+		} else {
+			PMD_TX_LOG(ERR, "No free tx descriptors to transmit");
+			break;
+		}
+	}
+	vq_update_avail_idx(txvq);
+
+	txvq->packets += nb_tx;
+
+	if (unlikely(virtqueue_kick_prepare(txvq))) {
+		virtqueue_notify(txvq);
+		PMD_TX_LOG(DEBUG, "Notified backend after xmit");
+	}
+
+	return nb_tx;
+}