static int net_init(struct XenDevice *xendev)
{
    struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev);

    /* read xenstore entries */
    if (netdev->mac == NULL) {
        netdev->mac = xenstore_read_be_str(&netdev->xendev, "mac");
    }

    /* do we have all we need? */
    if (netdev->mac == NULL) {
        return -1;
    }

    if (net_parse_macaddr(netdev->conf.macaddr.a, netdev->mac) < 0) {
        return -1;
    }

    netdev->nic = qemu_new_nic(&net_xen_info, &netdev->conf,
                               "xen", NULL, netdev);

    snprintf(qemu_get_queue(netdev->nic)->info_str,
             sizeof(qemu_get_queue(netdev->nic)->info_str),
             "nic: xenbus vif macaddr=%s", netdev->mac);

    /* fill info */
    xenstore_write_be_int(&netdev->xendev, "feature-rx-copy", 1);
    xenstore_write_be_int(&netdev->xendev, "feature-rx-flip", 0);

    return 0;
}

static void
eth_write(void *opaque, hwaddr addr,
          uint64_t val64, unsigned int size)
{
    struct xlx_ethlite *s = opaque;
    unsigned int base = 0;
    uint32_t value = val64;

    addr >>= 2;
    switch (addr) 
    {
        case R_TX_CTRL0:
        case R_TX_CTRL1:
            if (addr == R_TX_CTRL1)
                base = 0x800 / 4;

            D(qemu_log("%s addr=" TARGET_FMT_plx " val=%x\n",
                       __func__, addr * 4, value));
            if ((value & (CTRL_P | CTRL_S)) == CTRL_S) {
                qemu_send_packet(qemu_get_queue(s->nic),
                                 (void *) &s->regs[base],
                                 s->regs[base + R_TX_LEN0]);
                D(qemu_log("eth_tx %d\n", s->regs[base + R_TX_LEN0]));
                if (s->regs[base + R_TX_CTRL0] & CTRL_I)
                    eth_pulse_irq(s);
            } else if ((value & (CTRL_P | CTRL_S)) == (CTRL_P | CTRL_S)) {
                memcpy(&s->conf.macaddr.a[0], &s->regs[base], 6);
                if (s->regs[base + R_TX_CTRL0] & CTRL_I)
                    eth_pulse_irq(s);
            }

            /* We are fast and get ready pretty much immediately so
               we actually never flip the S nor P bits to one.  */
            s->regs[addr] = value & ~(CTRL_P | CTRL_S);
            break;

        /* Keep these native.  */
        case R_RX_CTRL0:
        case R_RX_CTRL1:
            if (!(value & CTRL_S)) {
                qemu_flush_queued_packets(qemu_get_queue(s->nic));
            }
            /* fall through */
        case R_TX_LEN0:
        case R_TX_LEN1:
        case R_TX_GIE0:
            D(qemu_log("%s addr=" TARGET_FMT_plx " val=%x\n",
                       __func__, addr * 4, value));
            s->regs[addr] = value;
            break;

        default:
            s->regs[addr] = tswap32(value);
            break;
    }
}

void dp83932_init(NICInfo *nd, hwaddr base, int it_shift,
                  MemoryRegion *address_space,
                  qemu_irq irq, void* mem_opaque,
                  void (*memory_rw)(void *opaque, hwaddr addr, uint8_t *buf, int len, int is_write))
{
    dp8393xState *s;

    qemu_check_nic_model(nd, "dp83932");

    s = g_malloc0(sizeof(dp8393xState));

    s->address_space = address_space;
    s->mem_opaque = mem_opaque;
    s->memory_rw = memory_rw;
    s->it_shift = it_shift;
    s->irq = irq;
    s->watchdog = timer_new_ns(QEMU_CLOCK_VIRTUAL, dp8393x_watchdog, s);
    s->regs[SONIC_SR] = 0x0004; /* only revision recognized by Linux */

    s->conf.macaddr = nd->macaddr;
    s->conf.peers.ncs[0] = nd->netdev;

    s->nic = qemu_new_nic(&net_dp83932_info, &s->conf, nd->model, nd->name, s);

    qemu_format_nic_info_str(qemu_get_queue(s->nic), s->conf.macaddr.a);
    qemu_register_reset(nic_reset, s);
    nic_reset(s);

    memory_region_init_io(&s->mmio, NULL, &dp8393x_ops, s,
                          "dp8393x", 0x40 << it_shift);
    memory_region_add_subregion(address_space, base, &s->mmio);
}

FpPort *fp_port_alloc(Rocker *r, char *sw_name,
                      MACAddr *start_mac, unsigned int index,
                      NICPeers *peers)
{
    FpPort *port = g_new0(FpPort, 1);

    if (!port) {
        return NULL;
    }

    port->r = r;
    port->index = index;
    port->pport = index + 1;

    /* front-panel switch port names are 1-based */

    port->name = g_strdup_printf("%sp%d", sw_name, port->pport);

    memcpy(port->conf.macaddr.a, start_mac, sizeof(port->conf.macaddr.a));
    port->conf.macaddr.a[5] += index;
    port->conf.bootindex = -1;
    port->conf.peers = *peers;

    port->nic = qemu_new_nic(&fp_port_info, &port->conf,
                             sw_name, NULL, port);
    qemu_format_nic_info_str(qemu_get_queue(port->nic),
                             port->conf.macaddr.a);

    fp_port_reset(port);

    return port;
}

static int fs_eth_init(SysBusDevice *sbd)
{
    DeviceState *dev = DEVICE(sbd);
    ETRAXFSEthState *s = ETRAX_FS_ETH(dev);

    if (!s->dma_out || !s->dma_in) {
        error_report("Unconnected ETRAX-FS Ethernet MAC");
        return -1;
    }

    s->dma_out->client.push = eth_tx_push;
    s->dma_out->client.opaque = s;
    s->dma_in->client.opaque = s;
    s->dma_in->client.pull = NULL;

    memory_region_init_io(&s->mmio, OBJECT(dev), &eth_ops, s,
                          "etraxfs-eth", 0x5c);
    sysbus_init_mmio(sbd, &s->mmio);

    qemu_macaddr_default_if_unset(&s->conf.macaddr);
    s->nic = qemu_new_nic(&net_etraxfs_info, &s->conf,
                          object_get_typename(OBJECT(s)), dev->id, s);
    qemu_format_nic_info_str(qemu_get_queue(s->nic), s->conf.macaddr.a);


    tdk_init(&s->phy);
    mdio_attach(&s->mdio_bus, &s->phy, s->phyaddr);
    return 0;
}

static void dp8393x_do_receiver_enable(dp8393xState *s)
{
    s->regs[SONIC_CR] &= ~SONIC_CR_RXDIS;
    if (dp8393x_can_receive(s->nic->ncs)) {
        qemu_flush_queued_packets(qemu_get_queue(s->nic));
    }
}

/* Release the memory allocated to a packet.  */
static void smc91c111_release_packet(smc91c111_state *s, int packet)
{
    s->allocated &= ~(1 << packet);
    if (s->tx_alloc == 0x80)
        smc91c111_tx_alloc(s);
    qemu_flush_queued_packets(qemu_get_queue(s->nic));
}

/* Send the packet currently in the TX FIFO */
static void stellaris_enet_send(stellaris_enet_state *s)
{
    int framelen = stellaris_txpacket_datalen(s);

    /* Ethernet header is in the FIFO but not in the datacount.
     * We don't implement explicit CRC, so just ignore any
     * CRC value in the FIFO.
     */
    framelen += 14;
    if ((s->tctl & SE_TCTL_PADEN) && framelen < 60) {
        memset(&s->tx_fifo[framelen + 2], 0, 60 - framelen);
        framelen = 60;
    }
    /* This MIN will have no effect unless the FIFO data is corrupt
     * (eg bad data from an incoming migration); otherwise the check
     * on the datalen at the start of writing the data into the FIFO
     * will have caught this. Silently write a corrupt half-packet,
     * which is what the hardware does in FIFO underrun situations.
     */
    framelen = MIN(framelen, ARRAY_SIZE(s->tx_fifo) - 2);
    qemu_send_packet(qemu_get_queue(s->nic), s->tx_fifo + 2, framelen);
    s->tx_fifo_len = 0;
    s->ris |= SE_INT_TXEMP;
    stellaris_enet_update(s);
    DPRINTF("Done TX\n");
}

static int eth_tx_push(void *opaque, unsigned char *buf, int len, bool eop)
{
    ETRAXFSEthState *eth = opaque;

    D(printf("%s buf=%p len=%d\n", __func__, buf, len));
    qemu_send_packet(qemu_get_queue(eth->nic), buf, len);
    return len;
}

/* Flush the TX FIFO.  */
static void smc91c111_do_tx(smc91c111_state *s)
{
    int i;
    int len;
    int control;
    int packetnum;
    uint8_t *p;

    if ((s->tcr & TCR_TXEN) == 0)
        return;
    if (s->tx_fifo_len == 0)
        return;
    for (i = 0; i < s->tx_fifo_len; i++) {
        packetnum = s->tx_fifo[i];
        p = &s->data[packetnum][0];
        /* Set status word.  */
        *(p++) = 0x01;
        *(p++) = 0x40;
        len = *(p++);
        len |= ((int)*(p++)) << 8;
        len -= 6;
        control = p[len + 1];
        if (control & 0x20)
            len++;
        /* ??? This overwrites the data following the buffer.
           Don't know what real hardware does.  */
        if (len < 64 && (s->tcr & TCR_PAD_EN)) {
            memset(p + len, 0, 64 - len);
            len = 64;
        }
#if 0
        {
            int add_crc;

            /* The card is supposed to append the CRC to the frame.
               However none of the other network traffic has the CRC
               appended.  Suspect this is low level ethernet detail we
               don't need to worry about.  */
            add_crc = (control & 0x10) || (s->tcr & TCR_NOCRC) == 0;
            if (add_crc) {
                uint32_t crc;

                crc = crc32(~0, p, len);
                memcpy(p + len, &crc, 4);
                len += 4;
            }
        }
#endif
        if (s->ctr & CTR_AUTO_RELEASE)
            /* Race?  */
            smc91c111_release_packet(s, packetnum);
        else if (s->tx_fifo_done_len < NUM_PACKETS)
            s->tx_fifo_done[s->tx_fifo_done_len++] = packetnum;
        qemu_send_packet(qemu_get_queue(s->nic), p, len);
    }
    s->tx_fifo_len = 0;
    smc91c111_update(s);
}

static void fp_port_set_link(FpPort *port, bool up)
{
    NetClientState *nc = qemu_get_queue(port->nic);

    if (up == nc->link_down) {
        nc->link_down = !up;
        nc->info->link_status_changed(nc);
    }
}

static void qemu_announce_self_iter(NICState *nic, void *opaque)
{
    uint8_t buf[60];
    int len;

    len = announce_self_create(buf, nic->conf->macaddr.a);

    qemu_send_packet_raw(qemu_get_queue(nic), buf, len);
}

static void ftgmac100_do_tx(Ftgmac100State *s)
{
    int frame_size = 0;
    uint8_t frame[FTGMAC100_MAX_FRAME_SIZE(s)];
    uint8_t *ptr = frame;
    uint32_t addr;

    addr = ftgmac100_find_txdes(s, s->tx_descriptor);

    while (1) {
        Ftgmac100Desc bd;
        int len;

        ftgmac100_read_bd(&bd, addr);
        if ((bd.des0 & FTGMAC100_TXDES0_TXDMA_OWN) == 0) {
            /* Run out of descriptors to transmit.  */
            s->isr |= FTGMAC100_INT_NO_NPTXBUF;
            break;
        }
        len = bd.des0 & 0x3FFF;
        if (frame_size + len > FTGMAC100_MAX_FRAME_SIZE(s)) {
            qemu_log_mask(LOG_GUEST_ERROR, "%s: frame too big : %d bytes\n",
                          __func__, len);
            len = FTGMAC100_MAX_FRAME_SIZE(s) - frame_size;
        }
        dma_memory_read(&address_space_memory, bd.des3, ptr, len);
        ptr += len;
        frame_size += len;
        if (bd.des0 & FTGMAC100_TXDES0_LTS) {
            /* Last buffer in frame.  */
            qemu_send_packet(qemu_get_queue(s->nic), frame, len);
            ptr = frame;
            frame_size = 0;
            if (bd.des1 & FTGMAC100_TXDES1_TXIC) {
                s->isr |= FTGMAC100_INT_XPKT_ETH;
            }
        }

        if (bd.des1 & FTGMAC100_TXDES1_TX2FIC) {
            s->isr |= FTGMAC100_INT_XPKT_FIFO;
        }
        bd.des0 &= ~FTGMAC100_TXDES0_TXDMA_OWN;

        /* Write back the modified descriptor.  */
        ftgmac100_write_bd(&bd, addr);
        /* Advance to the next descriptor.  */
        if (bd.des0 & ftgmac100_txdes0_edotr(s)) {
            addr = s->tx_ring;
        } else {
            addr += sizeof(Ftgmac100Desc);
        }
    }

    s->tx_descriptor = addr;

    ftgmac100_update_irq(s);
}

static void xilinx_ethlite_realize(DeviceState *dev, Error **errp)
{
    struct xlx_ethlite *s = XILINX_ETHLITE(dev);

    qemu_macaddr_default_if_unset(&s->conf.macaddr);
    s->nic = qemu_new_nic(&net_xilinx_ethlite_info, &s->conf,
                          object_get_typename(OBJECT(dev)), dev->id, s);
    qemu_format_nic_info_str(qemu_get_queue(s->nic), s->conf.macaddr.a);
}

int fp_port_eg(FpPort *port, const struct iovec *iov, int iovcnt)
{
    NetClientState *nc = qemu_get_queue(port->nic);

    if (port->enabled) {
        qemu_sendv_packet(nc, iov, iovcnt);
    }

    return ROCKER_OK;
}

static int spapr_vlan_init(VIOsPAPRDevice *sdev)
{
    VIOsPAPRVLANDevice *dev = VIO_SPAPR_VLAN_DEVICE(sdev);

    qemu_macaddr_default_if_unset(&dev->nicconf.macaddr);

    dev->nic = qemu_new_nic(&net_spapr_vlan_info, &dev->nicconf,
                            object_get_typename(OBJECT(sdev)), sdev->qdev.id, dev);
    qemu_format_nic_info_str(qemu_get_queue(dev->nic), dev->nicconf.macaddr.a);

    return 0;
}

static void e1000e_write_config(PCIDevice *pci_dev, uint32_t address,
                                uint32_t val, int len)
{
    E1000EState *s = E1000E(pci_dev);

    pci_default_write_config(pci_dev, address, val, len);

    if (range_covers_byte(address, len, PCI_COMMAND) &&
        (pci_dev->config[PCI_COMMAND] & PCI_COMMAND_MASTER)) {
        qemu_flush_queued_packets(qemu_get_queue(s->nic));
    }
}

static void phy_update_link(lan9118_state *s)
{
    /* Autonegotiation status mirrors link status.  */
    if (qemu_get_queue(s->nic)->link_down) {
        s->phy_status &= ~0x0024;
        s->phy_int |= PHY_INT_DOWN;
    } else {
        s->phy_status |= 0x0024;
        s->phy_int |= PHY_INT_ENERGYON;
        s->phy_int |= PHY_INT_AUTONEG_COMPLETE;
    }
    phy_update_irq(s);
}

static void etsec_realize(DeviceState *dev, Error **errp)
{
    eTSEC        *etsec = ETSEC_COMMON(dev);

    etsec->nic = qemu_new_nic(&net_etsec_info, &etsec->conf,
                              object_get_typename(OBJECT(dev)), dev->id, etsec);
    qemu_format_nic_info_str(qemu_get_queue(etsec->nic), etsec->conf.macaddr.a);


    etsec->bh     = qemu_bh_new(etsec_timer_hit, etsec);
    etsec->ptimer = ptimer_init(etsec->bh, PTIMER_POLICY_DEFAULT);
    ptimer_set_freq(etsec->ptimer, 100);
}

static target_ulong h_add_logical_lan_buffer(PowerPCCPU *cpu,
                                             sPAPREnvironment *spapr,
                                             target_ulong opcode,
                                             target_ulong *args)
{
    target_ulong reg = args[0];
    target_ulong buf = args[1];
    VIOsPAPRDevice *sdev = spapr_vio_find_by_reg(spapr->vio_bus, reg);
    VIOsPAPRVLANDevice *dev = VIO_SPAPR_VLAN_DEVICE(sdev);
    vlan_bd_t bd;

    DPRINTF("H_ADD_LOGICAL_LAN_BUFFER(0x" TARGET_FMT_lx
            ", 0x" TARGET_FMT_lx ")\n", reg, buf);

    if (!sdev) {
        hcall_dprintf("Bad device\n");
        return H_PARAMETER;
    }

    if ((check_bd(dev, buf, 4) < 0)
        || (VLAN_BD_LEN(buf) < 16)) {
        hcall_dprintf("Bad buffer enqueued\n");
        return H_PARAMETER;
    }

    if (!dev->isopen || dev->rx_bufs >= VLAN_MAX_BUFS) {
        return H_RESOURCE;
    }

    do {
        dev->add_buf_ptr += 8;
        if (dev->add_buf_ptr >= (VLAN_RX_BDS_LEN + VLAN_RX_BDS_OFF)) {
            dev->add_buf_ptr = VLAN_RX_BDS_OFF;
        }

        bd = vio_ldq(sdev, dev->buf_list + dev->add_buf_ptr);
    } while (bd & VLAN_BD_VALID);

    vio_stq(sdev, dev->buf_list + dev->add_buf_ptr, buf);

    dev->rx_bufs++;

    qemu_flush_queued_packets(qemu_get_queue(dev->nic));

    DPRINTF("h_add_logical_lan_buffer():  Added buf  ptr=%d  rx_bufs=%d"
            " bd=0x%016llx\n", dev->add_buf_ptr, dev->rx_bufs,
            (unsigned long long)buf);

    return H_SUCCESS;
}