/* SPDX-License-Identifier: BSD-3-Clause
 * Copyright(c) 2016-2018 Microsoft Corporation
 * Copyright(c) 2013-2016 Brocade Communications Systems, Inc.
 * All rights reserved.
 */

#include <stdint.h>
#include <string.h>
#include <stdio.h>
#include <errno.h>
#include <unistd.h>
#include <strings.h>
#include <malloc.h>

#include <rte_ethdev.h>
#include <rte_memcpy.h>
#include <rte_string_fns.h>
#include <rte_memzone.h>
#include <rte_malloc.h>
#include <rte_atomic.h>
#include <rte_bitmap.h>
#include <rte_branch_prediction.h>
#include <rte_ether.h>
#include <rte_common.h>
#include <rte_errno.h>
#include <rte_memory.h>
#include <rte_eal.h>
#include <rte_dev.h>
#include <rte_net.h>
#include <rte_bus_vmbus.h>
#include <rte_spinlock.h>

#include "hn_logs.h"
#include "hn_var.h"
#include "hn_rndis.h"
#include "hn_nvs.h"
#include "ndis.h"

#define HN_NVS_SEND_MSG_SIZE \
        (sizeof(struct vmbus_chanpkt_hdr) + sizeof(struct hn_nvs_rndis))

#define HN_TXD_CACHE_SIZE       32 /* per cpu tx_descriptor pool cache */
#define HN_RXQ_EVENT_DEFAULT    2048

struct hn_rxinfo {
        uint32_t        vlan_info;
        uint32_t        csum_info;
        uint32_t        hash_info;
        uint32_t        hash_value;
};

#define HN_RXINFO_VLAN                  0x0001
#define HN_RXINFO_CSUM                  0x0002
#define HN_RXINFO_HASHINF               0x0004
#define HN_RXINFO_HASHVAL               0x0008
#define HN_RXINFO_ALL                   \
        (HN_RXINFO_VLAN |               \
         HN_RXINFO_CSUM |               \
         HN_RXINFO_HASHINF |            \
         HN_RXINFO_HASHVAL)

#define HN_NDIS_VLAN_INFO_INVALID       0xffffffff
#define HN_NDIS_RXCSUM_INFO_INVALID     0
#define HN_NDIS_HASH_INFO_INVALID       0

/*
 * Per-transmit book keeping.
 * A slot in transmit ring (chim_index) is reserved for each transmit.
 *
 * There are two types of transmit:
 *   - buffered transmit where chimney buffer is used and RNDIS header
 *     is in the buffer. mbuf == NULL for this case.
 *
 *   - direct transmit where RNDIS header is in the in  rndis_pkt
 *     mbuf is freed after transmit.
 *
 * Descriptors come from per-port pool which is used
 * to limit number of outstanding requests per device.
 */
struct hn_txdesc {
        struct rte_mbuf *m;

        uint16_t        queue_id;
        uint32_t        chim_index;
        uint32_t        chim_size;
        uint32_t        data_size;
        uint32_t        packets;

        struct rndis_packet_msg *rndis_pkt;
};

#define HN_RNDIS_PKT_LEN                                \
        (sizeof(struct rndis_packet_msg) +              \
         RNDIS_PKTINFO_SIZE(NDIS_HASH_VALUE_SIZE) +     \
         RNDIS_PKTINFO_SIZE(NDIS_VLAN_INFO_SIZE) +      \
         RNDIS_PKTINFO_SIZE(NDIS_LSO2_INFO_SIZE) +      \
         RNDIS_PKTINFO_SIZE(NDIS_TXCSUM_INFO_SIZE))

#define HN_RNDIS_PKT_ALIGNED    RTE_ALIGN(HN_RNDIS_PKT_LEN, RTE_CACHE_LINE_SIZE)

/* Minimum space required for a packet */
#define HN_PKTSIZE_MIN(align) \
        RTE_ALIGN(RTE_ETHER_MIN_LEN + HN_RNDIS_PKT_LEN, align)

#define DEFAULT_TX_FREE_THRESH 32

static void
hn_update_packet_stats(struct hn_stats *stats, const struct rte_mbuf *m)
{
        uint32_t s = m->pkt_len;
        const struct rte_ether_addr *ea;

        if (s == 64) {
                stats->size_bins[1]++;
        } else if (s > 64 && s < 1024) {
                uint32_t bin;

                /* count zeros, and offset into correct bin */
                bin = (sizeof(s) * 8) - __builtin_clz(s) - 5;
                stats->size_bins[bin]++;
        } else {
                if (s < 64)
                        stats->size_bins[0]++;
                else if (s < 1519)
                        stats->size_bins[6]++;
                else
                        stats->size_bins[7]++;
        }

        ea = rte_pktmbuf_mtod(m, const struct rte_ether_addr *);
        if (rte_is_multicast_ether_addr(ea)) {
                if (rte_is_broadcast_ether_addr(ea))
                        stats->broadcast++;
                else
                        stats->multicast++;
        }
}

static inline unsigned int hn_rndis_pktlen(const struct rndis_packet_msg *pkt)
{
        return pkt->pktinfooffset + pkt->pktinfolen;
}

static inline uint32_t
hn_rndis_pktmsg_offset(uint32_t ofs)
{
        return ofs - offsetof(struct rndis_packet_msg, dataoffset);
}

static void hn_txd_init(struct rte_mempool *mp __rte_unused,
                        void *opaque, void *obj, unsigned int idx)
{
        struct hn_tx_queue *txq = opaque;
        struct hn_txdesc *txd = obj;

        memset(txd, 0, sizeof(*txd));

        txd->queue_id = txq->queue_id;
        txd->chim_index = NVS_CHIM_IDX_INVALID;
        txd->rndis_pkt = (struct rndis_packet_msg *)((char *)txq->tx_rndis
                + idx * HN_RNDIS_PKT_ALIGNED);
}

int
hn_chim_init(struct rte_eth_dev *dev)
{
        struct hn_data *hv = dev->data->dev_private;
        uint32_t i, chim_bmp_size;

        rte_spinlock_init(&hv->chim_lock);
        chim_bmp_size = rte_bitmap_get_memory_footprint(hv->chim_cnt);
        hv->chim_bmem = rte_zmalloc("hn_chim_bitmap", chim_bmp_size,
                                    RTE_CACHE_LINE_SIZE);
        if (hv->chim_bmem == NULL) {
                PMD_INIT_LOG(ERR, "failed to allocate bitmap size %u",
                             chim_bmp_size);
                return -1;
        }

        hv->chim_bmap = rte_bitmap_init(hv->chim_cnt,
                                        hv->chim_bmem, chim_bmp_size);
        if (hv->chim_bmap == NULL) {
                PMD_INIT_LOG(ERR, "failed to init chim bitmap");
                return -1;
        }

        for (i = 0; i < hv->chim_cnt; i++)
                rte_bitmap_set(hv->chim_bmap, i);

        return 0;
}

void
hn_chim_uninit(struct rte_eth_dev *dev)
{
        struct hn_data *hv = dev->data->dev_private;

        rte_bitmap_free(hv->chim_bmap);
        rte_free(hv->chim_bmem);
        hv->chim_bmem = NULL;
}

static uint32_t hn_chim_alloc(struct hn_data *hv)
{
        uint32_t index = NVS_CHIM_IDX_INVALID;
        uint64_t slab = 0;

        rte_spinlock_lock(&hv->chim_lock);
        if (rte_bitmap_scan(hv->chim_bmap, &index, &slab)) {
                index += rte_bsf64(slab);
                rte_bitmap_clear(hv->chim_bmap, index);
        }
        rte_spinlock_unlock(&hv->chim_lock);

        return index;
}

static void hn_chim_free(struct hn_data *hv, uint32_t chim_idx)
{
        if (chim_idx >= hv->chim_cnt) {
                PMD_DRV_LOG(ERR, "Invalid chimney index %u", chim_idx);
        } else {
                rte_spinlock_lock(&hv->chim_lock);
                rte_bitmap_set(hv->chim_bmap, chim_idx);
                rte_spinlock_unlock(&hv->chim_lock);
        }
}

static void hn_reset_txagg(struct hn_tx_queue *txq)
{
        txq->agg_szleft = txq->agg_szmax;
        txq->agg_pktleft = txq->agg_pktmax;
        txq->agg_txd = NULL;
        txq->agg_prevpkt = NULL;
}

int
hn_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)

{
        struct hn_data *hv = dev->data->dev_private;
        struct hn_tx_queue *txq;
        char name[RTE_MEMPOOL_NAMESIZE];
        uint32_t tx_free_thresh;
        int err = -ENOMEM;

        PMD_INIT_FUNC_TRACE();

        tx_free_thresh = tx_conf->tx_free_thresh;
        if (tx_free_thresh == 0)
                tx_free_thresh = RTE_MIN(nb_desc / 4,
                                         DEFAULT_TX_FREE_THRESH);

        if (tx_free_thresh + 3 >= nb_desc) {
                PMD_INIT_LOG(ERR,
                             "tx_free_thresh must be less than the number of TX entries minus 3(%u)."
                             " (tx_free_thresh=%u port=%u queue=%u)\n",
                             nb_desc - 3,
                             tx_free_thresh, dev->data->port_id, queue_idx);
                return -EINVAL;
        }

        txq = rte_zmalloc_socket("HN_TXQ", sizeof(*txq), RTE_CACHE_LINE_SIZE,
                                 socket_id);
        if (!txq)
                return -ENOMEM;

        txq->hv = hv;
        txq->chan = hv->channels[queue_idx];
        txq->port_id = dev->data->port_id;
        txq->queue_id = queue_idx;
        txq->free_thresh = tx_free_thresh;

        snprintf(name, sizeof(name),
                 "hn_txd_%u_%u", dev->data->port_id, queue_idx);

        PMD_INIT_LOG(DEBUG, "TX descriptor pool %s n=%u size=%zu",
                     name, nb_desc, sizeof(struct hn_txdesc));

        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),
                                              0, 0, NULL, NULL,
                                              hn_txd_init, txq,
                                              dev->device->numa_node, 0);
        if (txq->txdesc_pool == NULL) {
                PMD_DRV_LOG(ERR,
                            "mempool %s create failed: %d", name, rte_errno);
                goto error;
        }

        txq->agg_szmax  = RTE_MIN(hv->chim_szmax, hv->rndis_agg_size);
        txq->agg_pktmax = hv->rndis_agg_pkts;
        txq->agg_align  = hv->rndis_agg_align;

        hn_reset_txagg(txq);

        err = hn_vf_tx_queue_setup(dev, queue_idx, nb_desc,
                                     socket_id, tx_conf);
        if (err == 0) {
                dev->data->tx_queues[queue_idx] = txq;
                return 0;
        }

error:
        if (txq->txdesc_pool)
                rte_mempool_free(txq->txdesc_pool);
        rte_memzone_free(txq->tx_rndis_mz);
        rte_free(txq);
        return err;
}

void
hn_dev_tx_queue_info(struct rte_eth_dev *dev, uint16_t queue_id,
                     struct rte_eth_txq_info *qinfo)
{
        struct hn_tx_queue *txq = dev->data->tx_queues[queue_id];

        qinfo->nb_desc = txq->txdesc_pool->size;
        qinfo->conf.offloads = dev->data->dev_conf.txmode.offloads;
}

static struct hn_txdesc *hn_txd_get(struct hn_tx_queue *txq)
{
        struct hn_txdesc *txd;

        if (rte_mempool_get(txq->txdesc_pool, (void **)&txd)) {
                ++txq->stats.ring_full;
                PMD_TX_LOG(DEBUG, "tx pool exhausted!");
                return NULL;
        }

        txd->m = NULL;
        txd->packets = 0;
        txd->data_size = 0;
        txd->chim_size = 0;

        return txd;
}

static void hn_txd_put(struct hn_tx_queue *txq, struct hn_txdesc *txd)
{
        rte_mempool_put(txq->txdesc_pool, txd);
}

void
hn_dev_tx_queue_release(void *arg)
{
        struct hn_tx_queue *txq = arg;

        PMD_INIT_FUNC_TRACE();

        if (!txq)
                return;

        if (txq->txdesc_pool)
                rte_mempool_free(txq->txdesc_pool);

        rte_memzone_free(txq->tx_rndis_mz);
        rte_free(txq);
}

/*
 * Check the status of a Tx descriptor in the queue.
 *
 * returns:
 *  - -EINVAL              - offset outside of tx_descriptor pool.
 *  - RTE_ETH_TX_DESC_FULL - descriptor is not acknowledged by host.
 *  - RTE_ETH_TX_DESC_DONE - descriptor is available.
 */
int hn_dev_tx_descriptor_status(void *arg, uint16_t offset)
{
        const struct hn_tx_queue *txq = arg;

        hn_process_events(txq->hv, txq->queue_id, 0);

        if (offset >= rte_mempool_avail_count(txq->txdesc_pool))
                return -EINVAL;

        if (offset < rte_mempool_in_use_count(txq->txdesc_pool))
                return RTE_ETH_TX_DESC_FULL;
        else
                return RTE_ETH_TX_DESC_DONE;
}

static void
hn_nvs_send_completed(struct rte_eth_dev *dev, uint16_t queue_id,
                      unsigned long xactid, const struct hn_nvs_rndis_ack *ack)
{
        struct hn_data *hv = dev->data->dev_private;
        struct hn_txdesc *txd = (struct hn_txdesc *)xactid;
        struct hn_tx_queue *txq;

        /* Control packets are sent with xacid == 0 */
        if (!txd)
                return;

        txq = dev->data->tx_queues[queue_id];
        if (likely(ack->status == NVS_STATUS_OK)) {
                PMD_TX_LOG(DEBUG, "port %u:%u complete tx %u packets %u bytes %u",
                           txq->port_id, txq->queue_id, txd->chim_index,
                           txd->packets, txd->data_size);
                txq->stats.bytes += txd->data_size;
                txq->stats.packets += txd->packets;
        } else {
                PMD_DRV_LOG(NOTICE, "port %u:%u complete tx %u failed status %u",
                            txq->port_id, txq->queue_id, txd->chim_index, ack->status);
                ++txq->stats.errors;
        }

        if (txd->chim_index != NVS_CHIM_IDX_INVALID) {
                hn_chim_free(hv, txd->chim_index);
                txd->chim_index = NVS_CHIM_IDX_INVALID;
        }

        rte_pktmbuf_free(txd->m);
        hn_txd_put(txq, txd);
}

/* Handle transmit completion events */
static void
hn_nvs_handle_comp(struct rte_eth_dev *dev, uint16_t queue_id,
                   const struct vmbus_chanpkt_hdr *pkt,
                   const void *data)
{
        const struct hn_nvs_hdr *hdr = data;

        switch (hdr->type) {
        case NVS_TYPE_RNDIS_ACK:
                hn_nvs_send_completed(dev, queue_id, pkt->xactid, data);
                break;

        default:
                PMD_DRV_LOG(NOTICE, "unexpected send completion type %u",
                           hdr->type);
        }
}

/* Parse per-packet info (meta data) */
static int
hn_rndis_rxinfo(const void *info_data, unsigned int info_dlen,
                struct hn_rxinfo *info)
{
        const struct rndis_pktinfo *pi = info_data;
        uint32_t mask = 0;

        while (info_dlen != 0) {
                const void *data;
                uint32_t dlen;

                if (unlikely(info_dlen < sizeof(*pi)))
                        return -EINVAL;

                if (unlikely(info_dlen < pi->size))
                        return -EINVAL;
                info_dlen -= pi->size;

                if (unlikely(pi->size & RNDIS_PKTINFO_SIZE_ALIGNMASK))
                        return -EINVAL;
                if (unlikely(pi->size < pi->offset))
                        return -EINVAL;

                dlen = pi->size - pi->offset;
                data = pi->data;

                switch (pi->type) {
                case NDIS_PKTINFO_TYPE_VLAN:
                        if (unlikely(dlen < NDIS_VLAN_INFO_SIZE))
                                return -EINVAL;
                        info->vlan_info = *((const uint32_t *)data);
                        mask |= HN_RXINFO_VLAN;
                        break;

                case NDIS_PKTINFO_TYPE_CSUM:
                        if (unlikely(dlen < NDIS_RXCSUM_INFO_SIZE))
                                return -EINVAL;
                        info->csum_info = *((const uint32_t *)data);
                        mask |= HN_RXINFO_CSUM;
                        break;

                case NDIS_PKTINFO_TYPE_HASHVAL:
                        if (unlikely(dlen < NDIS_HASH_VALUE_SIZE))
                                return -EINVAL;
                        info->hash_value = *((const uint32_t *)data);
                        mask |= HN_RXINFO_HASHVAL;
                        break;

                case NDIS_PKTINFO_TYPE_HASHINF:
                        if (unlikely(dlen < NDIS_HASH_INFO_SIZE))
                                return -EINVAL;
                        info->hash_info = *((const uint32_t *)data);
                        mask |= HN_RXINFO_HASHINF;
                        break;

                default:
                        goto next;
                }

                if (mask == HN_RXINFO_ALL)
                        break; /* All found; done */
next:
                pi = (const struct rndis_pktinfo *)
                    ((const uint8_t *)pi + pi->size);
        }

        /*
         * Final fixup.
         * - If there is no hash value, invalidate the hash info.
         */
        if (!(mask & HN_RXINFO_HASHVAL))
                info->hash_info = HN_NDIS_HASH_INFO_INVALID;
        return 0;
}

static void hn_rx_buf_free_cb(void *buf __rte_unused, void *opaque)
{
        struct hn_rx_bufinfo *rxb = opaque;
        struct hn_rx_queue *rxq = rxb->rxq;

        rte_atomic32_dec(&rxq->rxbuf_outstanding);
        hn_nvs_ack_rxbuf(rxb->chan, rxb->xactid);
}

static struct hn_rx_bufinfo *hn_rx_buf_init(struct hn_rx_queue *rxq,
                                            const struct vmbus_chanpkt_rxbuf *pkt)
{
        struct hn_rx_bufinfo *rxb;

        rxb = rxq->rxbuf_info + pkt->hdr.xactid;
        rxb->chan = rxq->chan;
        rxb->xactid = pkt->hdr.xactid;
        rxb->rxq = rxq;

        rxb->shinfo.free_cb = hn_rx_buf_free_cb;
        rxb->shinfo.fcb_opaque = rxb;
        rte_mbuf_ext_refcnt_set(&rxb->shinfo, 1);
        return rxb;
}

static void hn_rxpkt(struct hn_rx_queue *rxq, struct hn_rx_bufinfo *rxb,
                     uint8_t *data, unsigned int headroom, unsigned int dlen,
                     const struct hn_rxinfo *info)
{
        struct hn_data *hv = rxq->hv;
        struct rte_mbuf *m;
        bool use_extbuf = false;

        m = rte_pktmbuf_alloc(rxq->mb_pool);
        if (unlikely(!m)) {
                struct rte_eth_dev *dev =
                        &rte_eth_devices[rxq->port_id];

                dev->data->rx_mbuf_alloc_failed++;
                return;
        }

        /*
         * For large packets, avoid copy if possible but need to keep
         * some space available in receive area for later packets.
         */
        if (hv->rx_extmbuf_enable && dlen > hv->rx_copybreak &&
            (uint32_t)rte_atomic32_read(&rxq->rxbuf_outstanding) <
                        hv->rxbuf_section_cnt / 2) {
                struct rte_mbuf_ext_shared_info *shinfo;
                const void *rxbuf;
                rte_iova_t iova;

                /*
                 * Build an external mbuf that points to recveive area.
                 * Use refcount to handle multiple packets in same
                 * receive buffer section.
                 */
                rxbuf = hv->rxbuf_res->addr;
                iova = rte_mem_virt2iova(rxbuf) + RTE_PTR_DIFF(data, rxbuf);
                shinfo = &rxb->shinfo;

                /* shinfo is already set to 1 by the caller */
                if (rte_mbuf_ext_refcnt_update(shinfo, 1) == 2)
                        rte_atomic32_inc(&rxq->rxbuf_outstanding);

                rte_pktmbuf_attach_extbuf(m, data, iova,
                                          dlen + headroom, shinfo);
                m->data_off = headroom;
                use_extbuf = true;
        } else {
                /* Mbuf's in pool must be large enough to hold small packets */
                if (unlikely(rte_pktmbuf_tailroom(m) < dlen)) {
                        rte_pktmbuf_free_seg(m);
                        ++rxq->stats.errors;
                        return;
                }
                rte_memcpy(rte_pktmbuf_mtod(m, void *),
                           data + headroom, dlen);
        }

        m->port = rxq->port_id;
        m->pkt_len = dlen;
        m->data_len = dlen;
        m->packet_type = rte_net_get_ptype(m, NULL,
                                           RTE_PTYPE_L2_MASK |
                                           RTE_PTYPE_L3_MASK |
                                           RTE_PTYPE_L4_MASK);

        if (info->vlan_info != HN_NDIS_VLAN_INFO_INVALID) {
                m->vlan_tci = info->vlan_info;
                m->ol_flags |= PKT_RX_VLAN_STRIPPED | PKT_RX_VLAN;

                /* NDIS always strips tag, put it back if necessary */
                if (!hv->vlan_strip && rte_vlan_insert(&m)) {
                        PMD_DRV_LOG(DEBUG, "vlan insert failed");
                        ++rxq->stats.errors;
                        if (use_extbuf)
                                rte_pktmbuf_detach_extbuf(m);
                        rte_pktmbuf_free(m);
                        return;
                }
        }

        if (info->csum_info != HN_NDIS_RXCSUM_INFO_INVALID) {
                if (info->csum_info & NDIS_RXCSUM_INFO_IPCS_OK)
                        m->ol_flags |= PKT_RX_IP_CKSUM_GOOD;

                if (info->csum_info & (NDIS_RXCSUM_INFO_UDPCS_OK
                                       | NDIS_RXCSUM_INFO_TCPCS_OK))
                        m->ol_flags |= PKT_RX_L4_CKSUM_GOOD;
                else if (info->csum_info & (NDIS_RXCSUM_INFO_TCPCS_FAILED
                                            | NDIS_RXCSUM_INFO_UDPCS_FAILED))
                        m->ol_flags |= PKT_RX_L4_CKSUM_BAD;
        }

        if (info->hash_info != HN_NDIS_HASH_INFO_INVALID) {
                m->ol_flags |= PKT_RX_RSS_HASH;
                m->hash.rss = info->hash_value;
        }

        PMD_RX_LOG(DEBUG,
                   "port %u:%u RX id %"PRIu64" size %u type %#x ol_flags %#"PRIx64,
                   rxq->port_id, rxq->queue_id, rxb->xactid,
                   m->pkt_len, m->packet_type, m->ol_flags);

        ++rxq->stats.packets;
        rxq->stats.bytes += m->pkt_len;
        hn_update_packet_stats(&rxq->stats, m);

        if (unlikely(rte_ring_sp_enqueue(rxq->rx_ring, m) != 0)) {
                ++rxq->stats.ring_full;
                PMD_RX_LOG(DEBUG, "rx ring full");
                if (use_extbuf)
                        rte_pktmbuf_detach_extbuf(m);
                rte_pktmbuf_free(m);
        }
}

static void hn_rndis_rx_data(struct hn_rx_queue *rxq,
                             struct hn_rx_bufinfo *rxb,
                             void *data, uint32_t dlen)
{
        unsigned int data_off, data_len;
        unsigned int pktinfo_off, pktinfo_len;
        const struct rndis_packet_msg *pkt = data;
        struct hn_rxinfo info = {
                .vlan_info = HN_NDIS_VLAN_INFO_INVALID,
                .csum_info = HN_NDIS_RXCSUM_INFO_INVALID,
                .hash_info = HN_NDIS_HASH_INFO_INVALID,
        };
        int err;

        hn_rndis_dump(pkt);

        if (unlikely(dlen < sizeof(*pkt)))
                goto error;

        if (unlikely(dlen < pkt->len))
                goto error; /* truncated RNDIS from host */

        if (unlikely(pkt->len < pkt->datalen
                     + pkt->oobdatalen + pkt->pktinfolen))
                goto error;

        if (unlikely(pkt->datalen == 0))
                goto error;

        /* Check offsets. */
        if (unlikely(pkt->dataoffset < RNDIS_PACKET_MSG_OFFSET_MIN))
                goto error;

        if (likely(pkt->pktinfooffset > 0) &&
            unlikely(pkt->pktinfooffset < RNDIS_PACKET_MSG_OFFSET_MIN ||
                     (pkt->pktinfooffset & RNDIS_PACKET_MSG_OFFSET_ALIGNMASK)))
                goto error;

        data_off = RNDIS_PACKET_MSG_OFFSET_ABS(pkt->dataoffset);
        data_len = pkt->datalen;
        pktinfo_off = RNDIS_PACKET_MSG_OFFSET_ABS(pkt->pktinfooffset);
        pktinfo_len = pkt->pktinfolen;

        if (likely(pktinfo_len > 0)) {
                err = hn_rndis_rxinfo((const uint8_t *)pkt + pktinfo_off,
                                      pktinfo_len, &info);
                if (err)
                        goto error;
        }

        /* overflow check */
        if (data_len > data_len + data_off || data_len + data_off > pkt->len)
                goto error;

        if (unlikely(data_len < RTE_ETHER_HDR_LEN))
                goto error;

        hn_rxpkt(rxq, rxb, data, data_off, data_len, &info);
        return;
error:
        ++rxq->stats.errors;
}

static void
hn_rndis_receive(struct rte_eth_dev *dev, struct hn_rx_queue *rxq,
                 struct hn_rx_bufinfo *rxb, void *buf, uint32_t len)
{
        const struct rndis_msghdr *hdr = buf;

        switch (hdr->type) {
        case RNDIS_PACKET_MSG:
                if (dev->data->dev_started)
                        hn_rndis_rx_data(rxq, rxb, buf, len);
                break;

        case RNDIS_INDICATE_STATUS_MSG:
                hn_rndis_link_status(dev, buf);
                break;

        case RNDIS_INITIALIZE_CMPLT:
        case RNDIS_QUERY_CMPLT:
        case RNDIS_SET_CMPLT:
                hn_rndis_receive_response(rxq->hv, buf, len);
                break;

        default:
                PMD_DRV_LOG(NOTICE,
                            "unexpected RNDIS message (type %#x len %u)",
                            hdr->type, len);
                break;
        }
}

static void
hn_nvs_handle_rxbuf(struct rte_eth_dev *dev,
                    struct hn_data *hv,
                    struct hn_rx_queue *rxq,
                    const struct vmbus_chanpkt_hdr *hdr,
                    const void *buf)
{
        const struct vmbus_chanpkt_rxbuf *pkt;
        const struct hn_nvs_hdr *nvs_hdr = buf;
        uint32_t rxbuf_sz = hv->rxbuf_res->len;
        char *rxbuf = hv->rxbuf_res->addr;
        unsigned int i, hlen, count;
        struct hn_rx_bufinfo *rxb;

        /* At minimum we need type header */
        if (unlikely(vmbus_chanpkt_datalen(hdr) < sizeof(*nvs_hdr))) {
                PMD_RX_LOG(ERR, "invalid receive nvs RNDIS");
                return;
        }

        /* Make sure that this is a RNDIS message. */
        if (unlikely(nvs_hdr->type != NVS_TYPE_RNDIS)) {
                PMD_RX_LOG(ERR, "nvs type %u, not RNDIS",
                           nvs_hdr->type);
                return;
        }

        hlen = vmbus_chanpkt_getlen(hdr->hlen);
        if (unlikely(hlen < sizeof(*pkt))) {
                PMD_RX_LOG(ERR, "invalid rxbuf chanpkt");
                return;
        }

        pkt = container_of(hdr, const struct vmbus_chanpkt_rxbuf, hdr);
        if (unlikely(pkt->rxbuf_id != NVS_RXBUF_SIG)) {
                PMD_RX_LOG(ERR, "invalid rxbuf_id 0x%08x",
                           pkt->rxbuf_id);
                return;
        }

        count = pkt->rxbuf_cnt;
        if (unlikely(hlen < offsetof(struct vmbus_chanpkt_rxbuf,
                                     rxbuf[count]))) {
                PMD_RX_LOG(ERR, "invalid rxbuf_cnt %u", count);
                return;
        }

        if (pkt->hdr.xactid > hv->rxbuf_section_cnt) {
                PMD_RX_LOG(ERR, "invalid rxbuf section id %" PRIx64,
                           pkt->hdr.xactid);
                return;
        }

        /* Setup receive buffer info to allow for callback */
        rxb = hn_rx_buf_init(rxq, pkt);

        /* Each range represents 1 RNDIS pkt that contains 1 Ethernet frame */
        for (i = 0; i < count; ++i) {
                unsigned int ofs, len;

                ofs = pkt->rxbuf[i].ofs;
                len = pkt->rxbuf[i].len;

                if (unlikely(ofs + len > rxbuf_sz)) {
                        PMD_RX_LOG(ERR,
                                   "%uth RNDIS msg overflow ofs %u, len %u",
                                   i, ofs, len);
                        continue;
                }

                if (unlikely(len == 0)) {
                        PMD_RX_LOG(ERR, "%uth RNDIS msg len %u", i, len);
                        continue;
                }

                hn_rndis_receive(dev, rxq, rxb,
                                 rxbuf + ofs, len);
        }

        /* Send ACK now if external mbuf not used */
        if (rte_mbuf_ext_refcnt_update(&rxb->shinfo, -1) == 0)
                hn_nvs_ack_rxbuf(rxb->chan, rxb->xactid);
}

/*
 * Called when NVS inband events are received.
 * Send up a two part message with port_id and the NVS message
 * to the pipe to the netvsc-vf-event control thread.
 */
static void hn_nvs_handle_notify(struct rte_eth_dev *dev,
                                 const struct vmbus_chanpkt_hdr *pkt,
                                 const void *data)
{
        const struct hn_nvs_hdr *hdr = data;

        switch (hdr->type) {
        case NVS_TYPE_TXTBL_NOTE:
                /* Transmit indirection table has locking problems
                 * in DPDK and therefore not implemented
                 */
                PMD_DRV_LOG(DEBUG, "host notify of transmit indirection table");
                break;

        case NVS_TYPE_VFASSOC_NOTE:
                hn_nvs_handle_vfassoc(dev, pkt, data);
                break;

        default:
                PMD_DRV_LOG(INFO,
                            "got notify, nvs type %u", hdr->type);
        }
}

struct hn_rx_queue *hn_rx_queue_alloc(struct hn_data *hv,
                                      uint16_t queue_id,
                                      unsigned int socket_id)
{
        struct hn_rx_queue *rxq;

        rxq = rte_zmalloc_socket("HN_RXQ", sizeof(*rxq),
                                 RTE_CACHE_LINE_SIZE, socket_id);
        if (!rxq)
                return NULL;

        rxq->hv = hv;
        rxq->chan = hv->channels[queue_id];
        rte_spinlock_init(&rxq->ring_lock);
        rxq->port_id = hv->port_id;
        rxq->queue_id = queue_id;
        rxq->event_sz = HN_RXQ_EVENT_DEFAULT;
        rxq->event_buf = rte_malloc_socket("HN_EVENTS", HN_RXQ_EVENT_DEFAULT,
                                           RTE_CACHE_LINE_SIZE, socket_id);
        if (!rxq->event_buf) {
                rte_free(rxq);
                return NULL;
        }

        /* setup rxbuf_info for non-primary queue */
        if (queue_id) {
                rxq->rxbuf_info = rte_calloc("HN_RXBUF_INFO",
                                        hv->rxbuf_section_cnt,
                                        sizeof(*rxq->rxbuf_info),
                                        RTE_CACHE_LINE_SIZE);

                if (!rxq->rxbuf_info) {
                        PMD_DRV_LOG(ERR,
                                "Could not allocate rxbuf info for queue %d\n",
                                queue_id);
                        rte_free(rxq->event_buf);
                        rte_free(rxq);
                        return NULL;
                }
        }

        return rxq;
}

void
hn_dev_rx_queue_info(struct rte_eth_dev *dev, uint16_t queue_id,
                     struct rte_eth_rxq_info *qinfo)
{
        struct hn_rx_queue *rxq = dev->data->rx_queues[queue_id];

        qinfo->mp = rxq->mb_pool;
        qinfo->nb_desc = rxq->rx_ring->size;
        qinfo->conf.offloads = dev->data->dev_conf.rxmode.offloads;
}

int
hn_dev_rx_queue_setup(struct rte_eth_dev *dev,
                      uint16_t queue_idx, uint16_t nb_desc,
                      unsigned int socket_id,
                      const struct rte_eth_rxconf *rx_conf,
                      struct rte_mempool *mp)
{
        struct hn_data *hv = dev->data->dev_private;
        char ring_name[RTE_RING_NAMESIZE];
        struct hn_rx_queue *rxq;
        unsigned int count;
        int error = -ENOMEM;

        PMD_INIT_FUNC_TRACE();

        if (queue_idx == 0) {
                rxq = hv->primary;
        } else {
                rxq = hn_rx_queue_alloc(hv, queue_idx, socket_id);
                if (!rxq)
                        return -ENOMEM;
        }

        rxq->mb_pool = mp;
        count = rte_mempool_avail_count(mp) / dev->data->nb_rx_queues;
        if (nb_desc == 0 || nb_desc > count)
                nb_desc = count;

        /*
         * Staging ring from receive event logic to rx_pkts.
         * rx_pkts assumes caller is handling multi-thread issue.
         * event logic has locking.
         */
        snprintf(ring_name, sizeof(ring_name),
                 "hn_rx_%u_%u", dev->data->port_id, queue_idx);
        rxq->rx_ring = rte_ring_create(ring_name,
                                       rte_align32pow2(nb_desc),
                                       socket_id, 0);
        if (!rxq->rx_ring)
                goto fail;

        error = hn_vf_rx_queue_setup(dev, queue_idx, nb_desc,
                                     socket_id, rx_conf, mp);
        if (error)
                goto fail;

        dev->data->rx_queues[queue_idx] = rxq;
        return 0;

fail:
        rte_ring_free(rxq->rx_ring);
        rte_free(rxq->rxbuf_info);
        rte_free(rxq->event_buf);
        rte_free(rxq);
        return error;
}

static void
hn_rx_queue_free(struct hn_rx_queue *rxq, bool keep_primary)
{

        if (!rxq)
                return;

        rte_ring_free(rxq->rx_ring);
        rxq->rx_ring = NULL;
        rxq->mb_pool = NULL;

        hn_vf_rx_queue_release(rxq->hv, rxq->queue_id);

        /* Keep primary queue to allow for control operations */
        if (keep_primary && rxq == rxq->hv->primary)
                return;

        rte_free(rxq->rxbuf_info);
        rte_free(rxq->event_buf);
        rte_free(rxq);
}

void
hn_dev_rx_queue_release(void *arg)
{
        struct hn_rx_queue *rxq = arg;

        PMD_INIT_FUNC_TRACE();

        hn_rx_queue_free(rxq, true);
}

/*
 * Get the number of used descriptor in a rx queue
 * For this device that means how many packets are pending in the ring.
 */
uint32_t
hn_dev_rx_queue_count(struct rte_eth_dev *dev, uint16_t queue_id)
{
        struct hn_rx_queue *rxq = dev->data->rx_queues[queue_id];

        return rte_ring_count(rxq->rx_ring);
}

/*
 * Check the status of a Rx descriptor in the queue
 *
 * returns:
 *  - -EINVAL               - offset outside of ring
 *  - RTE_ETH_RX_DESC_AVAIL - no data available yet
 *  - RTE_ETH_RX_DESC_DONE  - data is waiting in stagin ring
 */
int hn_dev_rx_queue_status(void *arg, uint16_t offset)
{
        const struct hn_rx_queue *rxq = arg;

        hn_process_events(rxq->hv, rxq->queue_id, 0);
        if (offset >= rxq->rx_ring->capacity)
                return -EINVAL;

        if (offset < rte_ring_count(rxq->rx_ring))
                return RTE_ETH_RX_DESC_DONE;
        else
                return RTE_ETH_RX_DESC_AVAIL;
}

int
hn_dev_tx_done_cleanup(void *arg, uint32_t free_cnt)
{
        struct hn_tx_queue *txq = arg;

        return hn_process_events(txq->hv, txq->queue_id, free_cnt);
}

/*
 * Process pending events on the channel.
 * Called from both Rx queue poll and Tx cleanup
 */
uint32_t hn_process_events(struct hn_data *hv, uint16_t queue_id,
                           uint32_t tx_limit)
{
        struct rte_eth_dev *dev = &rte_eth_devices[hv->port_id];
        struct hn_rx_queue *rxq;
        uint32_t bytes_read = 0;
        uint32_t tx_done = 0;
        int ret = 0;

        rxq = queue_id == 0 ? hv->primary : dev->data->rx_queues[queue_id];

        /*
         * Since channel is shared between Rx and TX queue need to have a lock
         * since DPDK does not force same CPU to be used for Rx/Tx.
         */
        if (unlikely(!rte_spinlock_trylock(&rxq->ring_lock)))
                return 0;

        for (;;) {
                const struct vmbus_chanpkt_hdr *pkt;
                uint32_t len = rxq->event_sz;
                const void *data;

retry:
                ret = rte_vmbus_chan_recv_raw(rxq->chan, rxq->event_buf, &len);
                if (ret == -EAGAIN)
                        break;  /* ring is empty */

                if (unlikely(ret == -ENOBUFS)) {
                        /* event buffer not large enough to read ring */

                        PMD_DRV_LOG(DEBUG,
                                    "event buffer expansion (need %u)", len);
                        rxq->event_sz = len + len / 4;
                        rxq->event_buf = rte_realloc(rxq->event_buf, rxq->event_sz,
                                                     RTE_CACHE_LINE_SIZE);
                        if (rxq->event_buf)
                                goto retry;
                        /* out of memory, no more events now */
                        rxq->event_sz = 0;
                        break;
                }

                if (unlikely(ret <= 0)) {
                        /* This indicates a failure to communicate (or worse) */
                        rte_exit(EXIT_FAILURE,
                                 "vmbus ring buffer error: %d", ret);
                }

                bytes_read += ret;
                pkt = (const struct vmbus_chanpkt_hdr *)rxq->event_buf;
                data = (char *)rxq->event_buf + vmbus_chanpkt_getlen(pkt->hlen);

                switch (pkt->type) {
                case VMBUS_CHANPKT_TYPE_COMP:
                        ++tx_done;
                        hn_nvs_handle_comp(dev, queue_id, pkt, data);
                        break;

                case VMBUS_CHANPKT_TYPE_RXBUF:
                        hn_nvs_handle_rxbuf(dev, hv, rxq, pkt, data);
                        break;

                case VMBUS_CHANPKT_TYPE_INBAND:
                        hn_nvs_handle_notify(dev, pkt, data);
                        break;

                default:
                        PMD_DRV_LOG(ERR, "unknown chan pkt %u", pkt->type);
                        break;
                }

                if (tx_limit && tx_done >= tx_limit)
                        break;
        }

        if (bytes_read > 0)
                rte_vmbus_chan_signal_read(rxq->chan, bytes_read);

        rte_spinlock_unlock(&rxq->ring_lock);

        return tx_done;
}

static void hn_append_to_chim(struct hn_tx_queue *txq,
                              struct rndis_packet_msg *pkt,
                              const struct rte_mbuf *m)
{
        struct hn_txdesc *txd = txq->agg_txd;
        uint8_t *buf = (uint8_t *)pkt;
        unsigned int data_offs;

        hn_rndis_dump(pkt);

        data_offs = RNDIS_PACKET_MSG_OFFSET_ABS(pkt->dataoffset);
        txd->chim_size += pkt->len;
        txd->data_size += m->pkt_len;
        ++txd->packets;
        hn_update_packet_stats(&txq->stats, m);

        for (; m; m = m->next) {
                uint16_t len = rte_pktmbuf_data_len(m);

                rte_memcpy(buf + data_offs,
                           rte_pktmbuf_mtod(m, const char *), len);
                data_offs += len;
        }
}

/*
 * Send pending aggregated data in chimney buffer (if any).
 * Returns error if send was unsuccessful because channel ring buffer
 * was full.
 */
static int hn_flush_txagg(struct hn_tx_queue *txq, bool *need_sig)

{
        struct hn_txdesc *txd = txq->agg_txd;
        struct hn_nvs_rndis rndis;
        int ret;

        if (!txd)
                return 0;

        rndis = (struct hn_nvs_rndis) {
                .type = NVS_TYPE_RNDIS,
                .rndis_mtype = NVS_RNDIS_MTYPE_DATA,
                .chim_idx = txd->chim_index,
                .chim_sz = txd->chim_size,
        };

        PMD_TX_LOG(DEBUG, "port %u:%u tx %u size %u",
                   txq->port_id, txq->queue_id, txd->chim_index, txd->chim_size);

        ret = hn_nvs_send(txq->chan, VMBUS_CHANPKT_FLAG_RC,
                          &rndis, sizeof(rndis), (uintptr_t)txd, need_sig);

        if (likely(ret == 0))
                hn_reset_txagg(txq);
        else if (ret == -EAGAIN) {
                PMD_TX_LOG(DEBUG, "port %u:%u channel full",
                           txq->port_id, txq->queue_id);
                ++txq->stats.channel_full;
        } else {
                ++txq->stats.errors;

                PMD_DRV_LOG(NOTICE, "port %u:%u send failed: %d",
                           txq->port_id, txq->queue_id, ret);
        }
        return ret;
}

/*
 * Try and find a place in a send chimney buffer to put
 * the small packet. If space is available, this routine
 * returns a pointer of where to place the data.
 * If no space, caller should try direct transmit.
 */
static void *
hn_try_txagg(struct hn_data *hv, struct hn_tx_queue *txq,
             struct hn_txdesc *txd, uint32_t pktsize)
{
        struct hn_txdesc *agg_txd = txq->agg_txd;
        struct rndis_packet_msg *pkt;
        void *chim;

        if (agg_txd) {
                unsigned int padding, olen;

                /*
                 * Update the previous RNDIS packet's total length,
                 * it can be increased due to the mandatory alignment
                 * padding for this RNDIS packet.  And update the
                 * aggregating txdesc's chimney sending buffer size
                 * accordingly.
                 *
                 * Zero-out the padding, as required by the RNDIS spec.
                 */
                pkt = txq->agg_prevpkt;
                olen = pkt->len;
                padding = RTE_ALIGN(olen, txq->agg_align) - olen;
                if (padding > 0) {
                        agg_txd->chim_size += padding;
                        pkt->len += padding;
                        memset((uint8_t *)pkt + olen, 0, padding);
                }

                chim = (uint8_t *)pkt + pkt->len;
                txq->agg_prevpkt = chim;
                txq->agg_pktleft--;
                txq->agg_szleft -= pktsize;
                if (txq->agg_szleft < HN_PKTSIZE_MIN(txq->agg_align)) {
                        /*
                         * Probably can't aggregate more packets,
                         * flush this aggregating txdesc proactively.
                         */
                        txq->agg_pktleft = 0;
                }

                hn_txd_put(txq, txd);
                return chim;
        }

        txd->chim_index = hn_chim_alloc(hv);
        if (txd->chim_index == NVS_CHIM_IDX_INVALID)
                return NULL;

        chim = (uint8_t *)hv->chim_res->addr
                        + txd->chim_index * hv->chim_szmax;

        txq->agg_txd = txd;
        txq->agg_pktleft = txq->agg_pktmax - 1;
        txq->agg_szleft = txq->agg_szmax - pktsize;
        txq->agg_prevpkt = chim;

        return chim;
}

static inline void *
hn_rndis_pktinfo_append(struct rndis_packet_msg *pkt,
                        uint32_t pi_dlen, uint32_t pi_type)
{
        const uint32_t pi_size = RNDIS_PKTINFO_SIZE(pi_dlen);
        struct rndis_pktinfo *pi;

        /*
         * Per-packet-info does not move; it only grows.
         *
         * NOTE:
         * pktinfooffset in this phase counts from the beginning
         * of rndis_packet_msg.
         */
        pi = (struct rndis_pktinfo *)((uint8_t *)pkt + hn_rndis_pktlen(pkt));

        pkt->pktinfolen += pi_size;

        pi->size = pi_size;
        pi->type = pi_type;
        pi->offset = RNDIS_PKTINFO_OFFSET;

        return pi->data;
}

/* Put RNDIS header and packet info on packet */
static void hn_encap(struct rndis_packet_msg *pkt,
                     uint16_t queue_id,
                     const struct rte_mbuf *m)
{
        unsigned int hlen = m->l2_len + m->l3_len;
        uint32_t *pi_data;
        uint32_t pkt_hlen;

        pkt->type = RNDIS_PACKET_MSG;
        pkt->len = m->pkt_len;
        pkt->dataoffset = 0;
        pkt->datalen = m->pkt_len;
        pkt->oobdataoffset = 0;
        pkt->oobdatalen = 0;
        pkt->oobdataelements = 0;
        pkt->pktinfooffset = sizeof(*pkt);
        pkt->pktinfolen = 0;
        pkt->vchandle = 0;
        pkt->reserved = 0;

        /*
         * Set the hash value for this packet, to the queue_id to cause
         * TX done event for this packet on the right channel.
         */
        pi_data = hn_rndis_pktinfo_append(pkt, NDIS_HASH_VALUE_SIZE,
                                          NDIS_PKTINFO_TYPE_HASHVAL);
        *pi_data = queue_id;

        if (m->ol_flags & PKT_TX_VLAN_PKT) {
                pi_data = hn_rndis_pktinfo_append(pkt, NDIS_VLAN_INFO_SIZE,
                                                  NDIS_PKTINFO_TYPE_VLAN);
                *pi_data = m->vlan_tci;
        }

        if (m->ol_flags & PKT_TX_TCP_SEG) {
                pi_data = hn_rndis_pktinfo_append(pkt, NDIS_LSO2_INFO_SIZE,
                                                  NDIS_PKTINFO_TYPE_LSO);

                if (m->ol_flags & PKT_TX_IPV6) {
                        *pi_data = NDIS_LSO2_INFO_MAKEIPV6(hlen,
                                                           m->tso_segsz);
                } else {
                        *pi_data = NDIS_LSO2_INFO_MAKEIPV4(hlen,
                                                           m->tso_segsz);
                }
        } else if (m->ol_flags &
                   (PKT_TX_TCP_CKSUM | PKT_TX_UDP_CKSUM | PKT_TX_IP_CKSUM)) {
                pi_data = hn_rndis_pktinfo_append(pkt, NDIS_TXCSUM_INFO_SIZE,
                                                  NDIS_PKTINFO_TYPE_CSUM);
                *pi_data = 0;

                if (m->ol_flags & PKT_TX_IPV6)
                        *pi_data |= NDIS_TXCSUM_INFO_IPV6;
                if (m->ol_flags & PKT_TX_IPV4) {
                        *pi_data |= NDIS_TXCSUM_INFO_IPV4;

                        if (m->ol_flags & PKT_TX_IP_CKSUM)
                                *pi_data |= NDIS_TXCSUM_INFO_IPCS;
                }

                if (m->ol_flags & PKT_TX_TCP_CKSUM)
                        *pi_data |= NDIS_TXCSUM_INFO_MKTCPCS(hlen);
                else if (m->ol_flags & PKT_TX_UDP_CKSUM)
                        *pi_data |= NDIS_TXCSUM_INFO_MKUDPCS(hlen);
        }

        pkt_hlen = pkt->pktinfooffset + pkt->pktinfolen;
        /* Fixup RNDIS packet message total length */
        pkt->len += pkt_hlen;

        /* Convert RNDIS packet message offsets */
        pkt->dataoffset = hn_rndis_pktmsg_offset(pkt_hlen);
        pkt->pktinfooffset = hn_rndis_pktmsg_offset(pkt->pktinfooffset);
}

/* How many scatter gather list elements ar needed */
static unsigned int hn_get_slots(const struct rte_mbuf *m)
{
        unsigned int slots = 1; /* for RNDIS header */

        while (m) {
                unsigned int size = rte_pktmbuf_data_len(m);
                unsigned int offs = rte_mbuf_data_iova(m) & PAGE_MASK;

                slots += (offs + size + rte_mem_page_size() - 1) /
                                rte_mem_page_size();
                m = m->next;
        }

        return slots;
}

/* Build scatter gather list from chained mbuf */
static unsigned int hn_fill_sg(struct vmbus_gpa *sg,
                               const struct rte_mbuf *m)
{
        unsigned int segs = 0;

        while (m) {
                rte_iova_t addr = rte_mbuf_data_iova(m);
                unsigned int page = addr / rte_mem_page_size();
                unsigned int offset = addr & PAGE_MASK;
                unsigned int len = rte_pktmbuf_data_len(m);

                while (len > 0) {
                        unsigned int bytes = RTE_MIN(len,
                                        rte_mem_page_size() - offset);

                        sg[segs].page = page;
                        sg[segs].ofs = offset;
                        sg[segs].len = bytes;
                        segs++;

                        ++page;
                        offset = 0;
                        len -= bytes;
                }
                m = m->next;
        }

        return segs;
}

/* Transmit directly from mbuf */
static int hn_xmit_sg(struct hn_tx_queue *txq,
                      const struct hn_txdesc *txd, const struct rte_mbuf *m,
                      bool *need_sig)
{
        struct vmbus_gpa sg[hn_get_slots(m)];
        struct hn_nvs_rndis nvs_rndis = {
                .type = NVS_TYPE_RNDIS,
                .rndis_mtype = NVS_RNDIS_MTYPE_DATA,
                .chim_sz = txd->chim_size,
        };
        rte_iova_t addr;
        unsigned int segs;

        /* attach aggregation data if present */
        if (txd->chim_size > 0)
                nvs_rndis.chim_idx = txd->chim_index;
        else
                nvs_rndis.chim_idx = NVS_CHIM_IDX_INVALID;

        hn_rndis_dump(txd->rndis_pkt);

        /* pass IOVA of rndis header in first segment */
        addr = txq->tx_rndis_iova +
                ((char *)txd->rndis_pkt - (char *)txq->tx_rndis);

        sg[0].page = addr / rte_mem_page_size();
        sg[0].ofs = addr & PAGE_MASK;
        sg[0].len = RNDIS_PACKET_MSG_OFFSET_ABS(hn_rndis_pktlen(txd->rndis_pkt));
        segs = 1;

        hn_update_packet_stats(&txq->stats, m);

        segs += hn_fill_sg(sg + 1, m);

        PMD_TX_LOG(DEBUG, "port %u:%u tx %u segs %u size %u",
                   txq->port_id, txq->queue_id, txd->chim_index,
                   segs, nvs_rndis.chim_sz);

        return hn_nvs_send_sglist(txq->chan, sg, segs,
                                  &nvs_rndis, sizeof(nvs_rndis),
                                  (uintptr_t)txd, need_sig);
}

uint16_t
hn_xmit_pkts(void *ptxq, struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
{
        struct hn_tx_queue *txq = ptxq;
        uint16_t queue_id = txq->queue_id;
        struct hn_data *hv = txq->hv;
        struct rte_eth_dev *vf_dev;
        bool need_sig = false;
        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 */
        if (hv->vf_ctx.vf_vsc_switched) {
                rte_rwlock_read_lock(&hv->vf_lock);
                vf_dev = hn_get_vf_dev(hv);
                if (hv->vf_ctx.vf_vsc_switched && vf_dev &&
                    vf_dev->data->dev_started) {
                        void *sub_q = vf_dev->data->tx_queues[queue_id];

                        nb_tx = (*vf_dev->tx_pkt_burst)
                                        (sub_q, tx_pkts, nb_pkts);
                        rte_rwlock_read_unlock(&hv->vf_lock);
                        return nb_tx;
                }
                rte_rwlock_read_unlock(&hv->vf_lock);
        }

        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;
                struct rndis_packet_msg *pkt;
                struct hn_txdesc *txd;

                txd = hn_txd_get(txq);
                if (txd == NULL)
                        break;

                /* For small packets aggregate them in chimney buffer */
                if (m->pkt_len <= hv->tx_copybreak &&
                    pkt_size <= txq->agg_szmax) {
                        /* If this packet will not fit, then flush  */
                        if (txq->agg_pktleft == 0 ||
                            RTE_ALIGN(pkt_size, txq->agg_align) > txq->agg_szleft) {
                                if (hn_flush_txagg(txq, &need_sig))
                                        goto fail;
                        }


                        pkt = hn_try_txagg(hv, txq, txd, pkt_size);
                        if (unlikely(!pkt))
                                break;

                        hn_encap(pkt, queue_id, m);
                        hn_append_to_chim(txq, pkt, m);

                        rte_pktmbuf_free(m);

                        /* if buffer is full, flush */
                        if (txq->agg_pktleft == 0 &&
                            hn_flush_txagg(txq, &need_sig))
                                goto fail;
                } else {
                        /* Send any outstanding packets in buffer */
                        if (txq->agg_txd && hn_flush_txagg(txq, &need_sig))
                                goto fail;

                        pkt = txd->rndis_pkt;
                        txd->m = m;
                        txd->data_size = m->pkt_len;
                        ++txd->packets;

                        hn_encap(pkt, queue_id, m);

                        ret = hn_xmit_sg(txq, txd, m, &need_sig);
                        if (unlikely(ret != 0)) {
                                if (ret == -EAGAIN) {
                                        PMD_TX_LOG(DEBUG, "sg channel full");
                                        ++txq->stats.channel_full;
                                } else {
                                        PMD_DRV_LOG(NOTICE, "sg send failed: %d", ret);
                                        ++txq->stats.errors;
                                }
                                hn_txd_put(txq, txd);
                                goto fail;
                        }
                }
        }

        /* If partial buffer left, then try and send it.
         * if that fails, then reuse it on next send.
         */
        hn_flush_txagg(txq, &need_sig);

fail:
        if (need_sig)
                rte_vmbus_chan_signal_tx(txq->chan);

        return nb_tx;
}

static uint16_t
hn_recv_vf(uint16_t vf_port, const struct hn_rx_queue *rxq,
           struct rte_mbuf **rx_pkts, uint16_t nb_pkts)
{
        uint16_t i, n;

        if (unlikely(nb_pkts == 0))
                return 0;

        n = rte_eth_rx_burst(vf_port, rxq->queue_id, rx_pkts, nb_pkts);

        /* relabel the received mbufs */
        for (i = 0; i < n; i++)
                rx_pkts[i]->port = rxq->port_id;

        return n;
}

uint16_t
hn_recv_pkts(void *prxq, struct rte_mbuf **rx_pkts, uint16_t nb_pkts)
{
        struct hn_rx_queue *rxq = prxq;
        struct hn_data *hv = rxq->hv;
        struct rte_eth_dev *vf_dev;
        uint16_t nb_rcv;

        if (unlikely(hv->closed))
                return 0;

        /* Check for new completions (and hotplug) */
        if (likely(rte_ring_count(rxq->rx_ring) < nb_pkts))
                hn_process_events(hv, rxq->queue_id, 0);

        /* Always check the vmbus path for multicast and new flows */
        nb_rcv = rte_ring_sc_dequeue_burst(rxq->rx_ring,
                                           (void **)rx_pkts, nb_pkts, NULL);

        /* If VF is available, check that as well */
        if (hv->vf_ctx.vf_vsc_switched) {
                rte_rwlock_read_lock(&hv->vf_lock);
                vf_dev = hn_get_vf_dev(hv);
                if (hv->vf_ctx.vf_vsc_switched && 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);

                rte_rwlock_read_unlock(&hv->vf_lock);
        }
        return nb_rcv;
}

void
hn_dev_free_queues(struct rte_eth_dev *dev)
{
        unsigned int i;

        for (i = 0; i < dev->data->nb_rx_queues; i++) {
                struct hn_rx_queue *rxq = dev->data->rx_queues[i];

                hn_rx_queue_free(rxq, false);
                dev->data->rx_queues[i] = NULL;
        }
        dev->data->nb_rx_queues = 0;

        for (i = 0; i < dev->data->nb_tx_queues; i++) {
                hn_dev_tx_queue_release(dev->data->tx_queues[i]);
                dev->data->tx_queues[i] = NULL;
        }
        dev->data->nb_tx_queues = 0;
}