/*
* Core code for QEMU e1000e emulation
*
* Software developer's manuals:
* http://www.intel.com/content/dam/doc/datasheet/82574l-gbe-controller-datasheet.pdf
*
* Copyright (c) 2015 Ravello Systems LTD (http://ravellosystems.com)
* Developed by Daynix Computing LTD (http://www.daynix.com)
*
* Authors:
* Dmitry Fleytman <dmitry@daynix.com>
* Leonid Bloch <leonid@daynix.com>
* Yan Vugenfirer <yan@daynix.com>
*
* Based on work done by:
* Nir Peleg, Tutis Systems Ltd. for Qumranet Inc.
* Copyright (c) 2008 Qumranet
* Based on work done by:
* Copyright (c) 2007 Dan Aloni
* Copyright (c) 2004 Antony T Curtis
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/

#include "qemu/osdep.h"
#include "qemu/log.h"
#include "net/net.h"
#include "net/tap.h"
#include "hw/pci/msi.h"
#include "hw/pci/msix.h"
#include "sysemu/runstate.h"

#include "net_tx_pkt.h"
#include "net_rx_pkt.h"

#include "e1000x_common.h"
#include "e1000e_core.h"

#include "trace.h"

#define E1000E_MIN_XITR     (500) /* No more then 7813 interrupts per
                                     second according to spec 10.2.4.2 */
#define E1000E_MAX_TX_FRAGS (64)

static inline void
e1000e_set_interrupt_cause(E1000ECore *core, uint32_t val);

static inline void
e1000e_process_ts_option(E1000ECore *core, struct e1000_tx_desc *dp)
{
    if (le32_to_cpu(dp->upper.data) & E1000_TXD_EXTCMD_TSTAMP) {
        trace_e1000e_wrn_no_ts_support();
    }
}

static inline void
e1000e_process_snap_option(E1000ECore *core, uint32_t cmd_and_length)
{
    if (cmd_and_length & E1000_TXD_CMD_SNAP) {
        trace_e1000e_wrn_no_snap_support();
    }
}

static inline void
e1000e_raise_legacy_irq(E1000ECore *core)
{
    trace_e1000e_irq_legacy_notify(true);
    e1000x_inc_reg_if_not_full(core->mac, IAC);
    pci_set_irq(core->owner, 1);
}

static inline void
e1000e_lower_legacy_irq(E1000ECore *core)
{
    trace_e1000e_irq_legacy_notify(false);
    pci_set_irq(core->owner, 0);
}

static inline void
e1000e_intrmgr_rearm_timer(E1000IntrDelayTimer *timer)
{
    int64_t delay_ns = (int64_t) timer->core->mac[timer->delay_reg] *
                                 timer->delay_resolution_ns;

    trace_e1000e_irq_rearm_timer(timer->delay_reg << 2, delay_ns);

    timer_mod(timer->timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + delay_ns);

    timer->running = true;
}

static void
e1000e_intmgr_timer_resume(E1000IntrDelayTimer *timer)
{
    if (timer->running) {
        e1000e_intrmgr_rearm_timer(timer);
    }
}

static void
e1000e_intmgr_timer_pause(E1000IntrDelayTimer *timer)
{
    if (timer->running) {
        timer_del(timer->timer);
    }
}

static inline void
e1000e_intrmgr_stop_timer(E1000IntrDelayTimer *timer)
{
    if (timer->running) {
        timer_del(timer->timer);
        timer->running = false;
    }
}

static inline void
e1000e_intrmgr_fire_delayed_interrupts(E1000ECore *core)
{
    trace_e1000e_irq_fire_delayed_interrupts();
    e1000e_set_interrupt_cause(core, 0);
}

static void
e1000e_intrmgr_on_timer(void *opaque)
{
    E1000IntrDelayTimer *timer = opaque;

    trace_e1000e_irq_throttling_timer(timer->delay_reg << 2);

    timer->running = false;
    e1000e_intrmgr_fire_delayed_interrupts(timer->core);
}

static void
e1000e_intrmgr_on_throttling_timer(void *opaque)
{
    E1000IntrDelayTimer *timer = opaque;

    assert(!msix_enabled(timer->core->owner));

    timer->running = false;

    if (!timer->core->itr_intr_pending) {
        trace_e1000e_irq_throttling_no_pending_interrupts();
        return;
    }

    if (msi_enabled(timer->core->owner)) {
        trace_e1000e_irq_msi_notify_postponed();
        /* Clear msi_causes_pending to fire MSI eventually */
        timer->core->msi_causes_pending = 0;
        e1000e_set_interrupt_cause(timer->core, 0);
    } else {
        trace_e1000e_irq_legacy_notify_postponed();
        e1000e_set_interrupt_cause(timer->core, 0);
    }
}

static void
e1000e_intrmgr_on_msix_throttling_timer(void *opaque)
{
    E1000IntrDelayTimer *timer = opaque;
    int idx = timer - &timer->core->eitr[0];

    assert(msix_enabled(timer->core->owner));

    timer->running = false;

    if (!timer->core->eitr_intr_pending[idx]) {
        trace_e1000e_irq_throttling_no_pending_vec(idx);
        return;
    }

    trace_e1000e_irq_msix_notify_postponed_vec(idx);
    msix_notify(timer->core->owner, idx);
}

static void
e1000e_intrmgr_initialize_all_timers(E1000ECore *core, bool create)
{
    int i;

    core->radv.delay_reg = RADV;
    core->rdtr.delay_reg = RDTR;
    core->raid.delay_reg = RAID;
    core->tadv.delay_reg = TADV;
    core->tidv.delay_reg = TIDV;

    core->radv.delay_resolution_ns = E1000_INTR_DELAY_NS_RES;
    core->rdtr.delay_resolution_ns = E1000_INTR_DELAY_NS_RES;
    core->raid.delay_resolution_ns = E1000_INTR_DELAY_NS_RES;
    core->tadv.delay_resolution_ns = E1000_INTR_DELAY_NS_RES;
    core->tidv.delay_resolution_ns = E1000_INTR_DELAY_NS_RES;

    core->radv.core = core;
    core->rdtr.core = core;
    core->raid.core = core;
    core->tadv.core = core;
    core->tidv.core = core;

    core->itr.core = core;
    core->itr.delay_reg = ITR;
    core->itr.delay_resolution_ns = E1000_INTR_THROTTLING_NS_RES;

    for (i = 0; i < E1000E_MSIX_VEC_NUM; i++) {
        core->eitr[i].core = core;
        core->eitr[i].delay_reg = EITR + i;
        core->eitr[i].delay_resolution_ns = E1000_INTR_THROTTLING_NS_RES;
    }

    if (!create) {
        return;
    }

    core->radv.timer =
        timer_new_ns(QEMU_CLOCK_VIRTUAL, e1000e_intrmgr_on_timer, &core->radv);
    core->rdtr.timer =
        timer_new_ns(QEMU_CLOCK_VIRTUAL, e1000e_intrmgr_on_timer, &core->rdtr);
    core->raid.timer =
        timer_new_ns(QEMU_CLOCK_VIRTUAL, e1000e_intrmgr_on_timer, &core->raid);

    core->tadv.timer =
        timer_new_ns(QEMU_CLOCK_VIRTUAL, e1000e_intrmgr_on_timer, &core->tadv);
    core->tidv.timer =
        timer_new_ns(QEMU_CLOCK_VIRTUAL, e1000e_intrmgr_on_timer, &core->tidv);

    core->itr.timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
                                   e1000e_intrmgr_on_throttling_timer,
                                   &core->itr);

    for (i = 0; i < E1000E_MSIX_VEC_NUM; i++) {
        core->eitr[i].timer =
            timer_new_ns(QEMU_CLOCK_VIRTUAL,
                         e1000e_intrmgr_on_msix_throttling_timer,
                         &core->eitr[i]);
    }
}

static inline void
e1000e_intrmgr_stop_delay_timers(E1000ECore *core)
{
    e1000e_intrmgr_stop_timer(&core->radv);
    e1000e_intrmgr_stop_timer(&core->rdtr);
    e1000e_intrmgr_stop_timer(&core->raid);
    e1000e_intrmgr_stop_timer(&core->tidv);
    e1000e_intrmgr_stop_timer(&core->tadv);
}

static bool
e1000e_intrmgr_delay_rx_causes(E1000ECore *core, uint32_t *causes)
{
    uint32_t delayable_causes;
    uint32_t rdtr = core->mac[RDTR];
    uint32_t radv = core->mac[RADV];
    uint32_t raid = core->mac[RAID];

    if (msix_enabled(core->owner)) {
        return false;
    }

    delayable_causes = E1000_ICR_RXQ0 |
                       E1000_ICR_RXQ1 |
                       E1000_ICR_RXT0;

    if (!(core->mac[RFCTL] & E1000_RFCTL_ACK_DIS)) {
        delayable_causes |= E1000_ICR_ACK;
    }

    /* Clean up all causes that may be delayed */
    core->delayed_causes |= *causes & delayable_causes;
    *causes &= ~delayable_causes;

    /* Check if delayed RX interrupts disabled by client
       or if there are causes that cannot be delayed */
    if ((rdtr == 0) || (*causes != 0)) {
        return false;
    }

    /* Check if delayed RX ACK interrupts disabled by client
       and there is an ACK packet received */
    if ((raid == 0) && (core->delayed_causes & E1000_ICR_ACK)) {
        return false;
    }

    /* All causes delayed */
    e1000e_intrmgr_rearm_timer(&core->rdtr);

    if (!core->radv.running && (radv != 0)) {
        e1000e_intrmgr_rearm_timer(&core->radv);
    }

    if (!core->raid.running && (core->delayed_causes & E1000_ICR_ACK)) {
        e1000e_intrmgr_rearm_timer(&core->raid);
    }

    return true;
}

static bool
e1000e_intrmgr_delay_tx_causes(E1000ECore *core, uint32_t *causes)
{
    static const uint32_t delayable_causes = E1000_ICR_TXQ0 |
                                             E1000_ICR_TXQ1 |
                                             E1000_ICR_TXQE |
                                             E1000_ICR_TXDW;

    if (msix_enabled(core->owner)) {
        return false;
    }

    /* Clean up all causes that may be delayed */
    core->delayed_causes |= *causes & delayable_causes;
    *causes &= ~delayable_causes;

    /* If there are causes that cannot be delayed */
    if (*causes != 0) {
        return false;
    }

    /* All causes delayed */
    e1000e_intrmgr_rearm_timer(&core->tidv);

    if (!core->tadv.running && (core->mac[TADV] != 0)) {
        e1000e_intrmgr_rearm_timer(&core->tadv);
    }

    return true;
}

static uint32_t
e1000e_intmgr_collect_delayed_causes(E1000ECore *core)
{
    uint32_t res;

    if (msix_enabled(core->owner)) {
        assert(core->delayed_causes == 0);
        return 0;
    }

    res = core->delayed_causes;
    core->delayed_causes = 0;

    e1000e_intrmgr_stop_delay_timers(core);

    return res;
}

static void
e1000e_intrmgr_fire_all_timers(E1000ECore *core)
{
    int i;
    uint32_t val = e1000e_intmgr_collect_delayed_causes(core);

    trace_e1000e_irq_adding_delayed_causes(val, core->mac[ICR]);
    core->mac[ICR] |= val;

    if (core->itr.running) {
        timer_del(core->itr.timer);
        e1000e_intrmgr_on_throttling_timer(&core->itr);
    }

    for (i = 0; i < E1000E_MSIX_VEC_NUM; i++) {
        if (core->eitr[i].running) {
            timer_del(core->eitr[i].timer);
            e1000e_intrmgr_on_msix_throttling_timer(&core->eitr[i]);
        }
    }
}

static void
e1000e_intrmgr_resume(E1000ECore *core)
{
    int i;

    e1000e_intmgr_timer_resume(&core->radv);
    e1000e_intmgr_timer_resume(&core->rdtr);
    e1000e_intmgr_timer_resume(&core->raid);
    e1000e_intmgr_timer_resume(&core->tidv);
    e1000e_intmgr_timer_resume(&core->tadv);

    e1000e_intmgr_timer_resume(&core->itr);

    for (i = 0; i < E1000E_MSIX_VEC_NUM; i++) {
        e1000e_intmgr_timer_resume(&core->eitr[i]);
    }
}

static void
e1000e_intrmgr_pause(E1000ECore *core)
{
    int i;

    e1000e_intmgr_timer_pause(&core->radv);
    e1000e_intmgr_timer_pause(&core->rdtr);
    e1000e_intmgr_timer_pause(&core->raid);
    e1000e_intmgr_timer_pause(&core->tidv);
    e1000e_intmgr_timer_pause(&core->tadv);

    e1000e_intmgr_timer_pause(&core->itr);

    for (i = 0; i < E1000E_MSIX_VEC_NUM; i++) {
        e1000e_intmgr_timer_pause(&core->eitr[i]);
    }
}

static void
e1000e_intrmgr_reset(E1000ECore *core)
{
    int i;

    core->delayed_causes = 0;

    e1000e_intrmgr_stop_delay_timers(core);

    e1000e_intrmgr_stop_timer(&core->itr);

    for (i = 0; i < E1000E_MSIX_VEC_NUM; i++) {
        e1000e_intrmgr_stop_timer(&core->eitr[i]);
    }
}

static void
e1000e_intrmgr_pci_unint(E1000ECore *core)
{
    int i;

    timer_free(core->radv.timer);
    timer_free(core->rdtr.timer);
    timer_free(core->raid.timer);

    timer_free(core->tadv.timer);
    timer_free(core->tidv.timer);

    timer_free(core->itr.timer);

    for (i = 0; i < E1000E_MSIX_VEC_NUM; i++) {
        timer_free(core->eitr[i].timer);
    }
}

static void
e1000e_intrmgr_pci_realize(E1000ECore *core)
{
    e1000e_intrmgr_initialize_all_timers(core, true);
}

static inline bool
e1000e_rx_csum_enabled(E1000ECore *core)
{
    return (core->mac[RXCSUM] & E1000_RXCSUM_PCSD) ? false : true;
}

static inline bool
e1000e_rx_use_legacy_descriptor(E1000ECore *core)
{
    return (core->mac[RFCTL] & E1000_RFCTL_EXTEN) ? false : true;
}

static inline bool
e1000e_rx_use_ps_descriptor(E1000ECore *core)
{
    return !e1000e_rx_use_legacy_descriptor(core) &&
           (core->mac[RCTL] & E1000_RCTL_DTYP_PS);
}

static inline bool
e1000e_rss_enabled(E1000ECore *core)
{
    return E1000_MRQC_ENABLED(core->mac[MRQC]) &&
           !e1000e_rx_csum_enabled(core) &&
           !e1000e_rx_use_legacy_descriptor(core);
}

typedef struct E1000E_RSSInfo_st {
    bool enabled;
    uint32_t hash;
    uint32_t queue;
    uint32_t type;
} E1000E_RSSInfo;

static uint32_t
e1000e_rss_get_hash_type(E1000ECore *core, struct NetRxPkt *pkt)
{
    bool isip4, isip6, isudp, istcp;

    assert(e1000e_rss_enabled(core));

    net_rx_pkt_get_protocols(pkt, &isip4, &isip6, &isudp, &istcp);

    if (isip4) {
        bool fragment = net_rx_pkt_get_ip4_info(pkt)->fragment;

        trace_e1000e_rx_rss_ip4(fragment, istcp, core->mac[MRQC],
                                E1000_MRQC_EN_TCPIPV4(core->mac[MRQC]),
                                E1000_MRQC_EN_IPV4(core->mac[MRQC]));

        if (!fragment && istcp && E1000_MRQC_EN_TCPIPV4(core->mac[MRQC])) {
            return E1000_MRQ_RSS_TYPE_IPV4TCP;
        }

        if (E1000_MRQC_EN_IPV4(core->mac[MRQC])) {
            return E1000_MRQ_RSS_TYPE_IPV4;
        }
    } else if (isip6) {
        eth_ip6_hdr_info *ip6info = net_rx_pkt_get_ip6_info(pkt);

        bool ex_dis = core->mac[RFCTL] & E1000_RFCTL_IPV6_EX_DIS;
        bool new_ex_dis = core->mac[RFCTL] & E1000_RFCTL_NEW_IPV6_EXT_DIS;

        /*
         * Following two traces must not be combined because resulting
         * event will have 11 arguments totally and some trace backends
         * (at least "ust") have limitation of maximum 10 arguments per
         * event. Events with more arguments fail to compile for
         * backends like these.
         */
        trace_e1000e_rx_rss_ip6_rfctl(core->mac[RFCTL]);
        trace_e1000e_rx_rss_ip6(ex_dis, new_ex_dis, istcp,
                                ip6info->has_ext_hdrs,
                                ip6info->rss_ex_dst_valid,
                                ip6info->rss_ex_src_valid,
                                core->mac[MRQC],
                                E1000_MRQC_EN_TCPIPV6(core->mac[MRQC]),
                                E1000_MRQC_EN_IPV6EX(core->mac[MRQC]),
                                E1000_MRQC_EN_IPV6(core->mac[MRQC]));

        if ((!ex_dis || !ip6info->has_ext_hdrs) &&
            (!new_ex_dis || !(ip6info->rss_ex_dst_valid ||
                              ip6info->rss_ex_src_valid))) {

            if (istcp && !ip6info->fragment &&
                E1000_MRQC_EN_TCPIPV6(core->mac[MRQC])) {
                return E1000_MRQ_RSS_TYPE_IPV6TCP;
            }

            if (E1000_MRQC_EN_IPV6EX(core->mac[MRQC])) {
                return E1000_MRQ_RSS_TYPE_IPV6EX;
            }

        }

        if (E1000_MRQC_EN_IPV6(core->mac[MRQC])) {
            return E1000_MRQ_RSS_TYPE_IPV6;
        }

    }

    return E1000_MRQ_RSS_TYPE_NONE;
}

static uint32_t
e1000e_rss_calc_hash(E1000ECore *core,
                     struct NetRxPkt *pkt,
                     E1000E_RSSInfo *info)
{
    NetRxPktRssType type;

    assert(e1000e_rss_enabled(core));

    switch (info->type) {
    case E1000_MRQ_RSS_TYPE_IPV4:
        type = NetPktRssIpV4;
        break;
    case E1000_MRQ_RSS_TYPE_IPV4TCP:
        type = NetPktRssIpV4Tcp;
        break;
    case E1000_MRQ_RSS_TYPE_IPV6TCP:
        type = NetPktRssIpV6TcpEx;
        break;
    case E1000_MRQ_RSS_TYPE_IPV6:
        type = NetPktRssIpV6;
        break;
    case E1000_MRQ_RSS_TYPE_IPV6EX:
        type = NetPktRssIpV6Ex;
        break;
    default:
        assert(false);
        return 0;
    }

    return net_rx_pkt_calc_rss_hash(pkt, type, (uint8_t *) &core->mac[RSSRK]);
}

static void
e1000e_rss_parse_packet(E1000ECore *core,
                        struct NetRxPkt *pkt,
                        E1000E_RSSInfo *info)
{
    trace_e1000e_rx_rss_started();

    if (!e1000e_rss_enabled(core)) {
        info->enabled = false;
        info->hash = 0;
        info->queue = 0;
        info->type = 0;
        trace_e1000e_rx_rss_disabled();
        return;
    }

    info->enabled = true;

    info->type = e1000e_rss_get_hash_type(core, pkt);

    trace_e1000e_rx_rss_type(info->type);

    if (info->type == E1000_MRQ_RSS_TYPE_NONE) {
        info->hash = 0;
        info->queue = 0;
        return;
    }

    info->hash = e1000e_rss_calc_hash(core, pkt, info);
    info->queue = E1000_RSS_QUEUE(&core->mac[RETA], info->hash);
}

static void
e1000e_setup_tx_offloads(E1000ECore *core, struct e1000e_tx *tx)
{
    if (tx->props.tse && tx->cptse) {
        net_tx_pkt_build_vheader(tx->tx_pkt, true, true, tx->props.mss);
        net_tx_pkt_update_ip_checksums(tx->tx_pkt);
        e1000x_inc_reg_if_not_full(core->mac, TSCTC);
        return;
    }

    if (tx->sum_needed & E1000_TXD_POPTS_TXSM) {
        net_tx_pkt_build_vheader(tx->tx_pkt, false, true, 0);
    }

    if (tx->sum_needed & E1000_TXD_POPTS_IXSM) {
        net_tx_pkt_update_ip_hdr_checksum(tx->tx_pkt);
    }
}

static bool
e1000e_tx_pkt_send(E1000ECore *core, struct e1000e_tx *tx, int queue_index)
{
    int target_queue = MIN(core->max_queue_num, queue_index);
    NetClientState *queue = qemu_get_subqueue(core->owner_nic, target_queue);

    e1000e_setup_tx_offloads(core, tx);

    net_tx_pkt_dump(tx->tx_pkt);

    if ((core->phy[0][PHY_CTRL] & MII_CR_LOOPBACK) ||
        ((core->mac[RCTL] & E1000_RCTL_LBM_MAC) == E1000_RCTL_LBM_MAC)) {
        return net_tx_pkt_send_loopback(tx->tx_pkt, queue);
    } else {
        return net_tx_pkt_send(tx->tx_pkt, queue);
    }
}

static void
e1000e_on_tx_done_update_stats(E1000ECore *core, struct NetTxPkt *tx_pkt)
{
    static const int PTCregs[6] = { PTC64, PTC127, PTC255, PTC511,
                                    PTC1023, PTC1522 };

    size_t tot_len = net_tx_pkt_get_total_len(tx_pkt);

    e1000x_increase_size_stats(core->mac, PTCregs, tot_len);
    e1000x_inc_reg_if_not_full(core->mac, TPT);
    e1000x_grow_8reg_if_not_full(core->mac, TOTL, tot_len);

    switch (net_tx_pkt_get_packet_type(tx_pkt)) {
    case ETH_PKT_BCAST:
        e1000x_inc_reg_if_not_full(core->mac, BPTC);
        break;
    case ETH_PKT_MCAST:
        e1000x_inc_reg_if_not_full(core->mac, MPTC);
        break;
    case ETH_PKT_UCAST:
        break;
    default:
        g_assert_not_reached();
    }

    core->mac[GPTC] = core->mac[TPT];
    core->mac[GOTCL] = core->mac[TOTL];
    core->mac[GOTCH] = core->mac[TOTH];
}

static void
e1000e_process_tx_desc(E1000ECore *core,
                       struct e1000e_tx *tx,
                       struct e1000_tx_desc *dp,
                       int queue_index)
{
    uint32_t txd_lower = le32_to_cpu(dp->lower.data);
    uint32_t dtype = txd_lower & (E1000_TXD_CMD_DEXT | E1000_TXD_DTYP_D);
    unsigned int split_size = txd_lower & 0xffff;
    uint64_t addr;
    struct e1000_context_desc *xp = (struct e1000_context_desc *)dp;
    bool eop = txd_lower & E1000_TXD_CMD_EOP;

    if (dtype == E1000_TXD_CMD_DEXT) { /* context descriptor */
        e1000x_read_tx_ctx_descr(xp, &tx->props);
        e1000e_process_snap_option(core, le32_to_cpu(xp->cmd_and_length));
        return;
    } else if (dtype == (E1000_TXD_CMD_DEXT | E1000_TXD_DTYP_D)) {
        /* data descriptor */
        tx->sum_needed = le32_to_cpu(dp->upper.data) >> 8;
        tx->cptse = (txd_lower & E1000_TXD_CMD_TSE) ? 1 : 0;
        e1000e_process_ts_option(core, dp);
    } else {
        /* legacy descriptor */
        e1000e_process_ts_option(core, dp);
        tx->cptse = 0;
    }

    addr = le64_to_cpu(dp->buffer_addr);

    if (!tx->skip_cp) {
        if (!net_tx_pkt_add_raw_fragment(tx->tx_pkt, addr, split_size)) {
            tx->skip_cp = true;
        }
    }

    if (eop) {
        if (!tx->skip_cp && net_tx_pkt_parse(tx->tx_pkt)) {
            if (e1000x_vlan_enabled(core->mac) &&
                e1000x_is_vlan_txd(txd_lower)) {
                net_tx_pkt_setup_vlan_header_ex(tx->tx_pkt,
                    le16_to_cpu(dp->upper.fields.special), core->mac[VET]);
            }
            if (e1000e_tx_pkt_send(core, tx, queue_index)) {
                e1000e_on_tx_done_update_stats(core, tx->tx_pkt);
            }
        }

        tx->skip_cp = false;
        net_tx_pkt_reset(tx->tx_pkt);

        tx->sum_needed = 0;
        tx->cptse = 0;
    }
}

static inline uint32_t
e1000e_tx_wb_interrupt_cause(E1000ECore *core, int queue_idx)
{
    if (!msix_enabled(core->owner)) {
        return E1000_ICR_TXDW;
    }

    return (queue_idx == 0) ? E1000_ICR_TXQ0 : E1000_ICR_TXQ1;
}

static inline uint32_t
e1000e_rx_wb_interrupt_cause(E1000ECore *core, int queue_idx,
                             bool min_threshold_hit)
{
    if (!msix_enabled(core->owner)) {
        return E1000_ICS_RXT0 | (min_threshold_hit ? E1000_ICS_RXDMT0 : 0);
    }

    return (queue_idx == 0) ? E1000_ICR_RXQ0 : E1000_ICR_RXQ1;
}

static uint32_t
e1000e_txdesc_writeback(E1000ECore *core, dma_addr_t base,
                        struct e1000_tx_desc *dp, bool *ide, int queue_idx)
{
    uint32_t txd_upper, txd_lower = le32_to_cpu(dp->lower.data);

    if (!(txd_lower & E1000_TXD_CMD_RS) &&
        !(core->mac[IVAR] & E1000_IVAR_TX_INT_EVERY_WB)) {
        return 0;
    }

    *ide = (txd_lower & E1000_TXD_CMD_IDE) ? true : false;

    txd_upper = le32_to_cpu(dp->upper.data) | E1000_TXD_STAT_DD;

    dp->upper.data = cpu_to_le32(txd_upper);
    pci_dma_write(core->owner, base + ((char *)&dp->upper - (char *)dp),
                  &dp->upper, sizeof(dp->upper));
    return e1000e_tx_wb_interrupt_cause(core, queue_idx);
}

typedef struct E1000E_RingInfo_st {
    int dbah;
    int dbal;
    int dlen;
    int dh;
    int dt;
    int idx;
} E1000E_RingInfo;

static inline bool
e1000e_ring_empty(E1000ECore *core, const E1000E_RingInfo *r)
{
    return core->mac[r->dh] == core->mac[r->dt] ||
                core->mac[r->dt] >= core->mac[r->dlen] / E1000_RING_DESC_LEN;
}

static inline uint64_t
e1000e_ring_base(E1000ECore *core, const E1000E_RingInfo *r)
{
    uint64_t bah = core->mac[r->dbah];
    uint64_t bal = core->mac[r->dbal];

    return (bah << 32) + bal;
}

static inline uint64_t
e1000e_ring_head_descr(E1000ECore *core, const E1000E_RingInfo *r)
{
    return e1000e_ring_base(core, r) + E1000_RING_DESC_LEN * core->mac[r->dh];
}

static inline void
e1000e_ring_advance(E1000ECore *core, const E1000E_RingInfo *r, uint32_t count)
{
    core->mac[r->dh] += count;

    if (core->mac[r->dh] * E1000_RING_DESC_LEN >= core->mac[r->dlen]) {
        core->mac[r->dh] = 0;
    }
}

static inline uint32_t
e1000e_ring_free_descr_num(E1000ECore *core, const E1000E_RingInfo *r)
{
    trace_e1000e_ring_free_space(r->idx, core->mac[r->dlen],
                                 core->mac[r->dh],  core->mac[r->dt]);

    if (core->mac[r->dh] <= core->mac[r->dt]) {
        return core->mac[r->dt] - core->mac[r->dh];
    }

    if (core->mac[r->dh] > core->mac[r->dt]) {
        return core->mac[r->dlen] / E1000_RING_DESC_LEN +
               core->mac[r->dt] - core->mac[r->dh];
    }

    g_assert_not_reached();
    return 0;
}

static inline bool
e1000e_ring_enabled(E1000ECore *core, const E1000E_RingInfo *r)
{
    return core->mac[r->dlen] > 0;
}

static inline uint32_t
e1000e_ring_len(E1000ECore *core, const E1000E_RingInfo *r)
{
    return core->mac[r->dlen];
}

typedef struct E1000E_TxRing_st {
    const E1000E_RingInfo *i;
    struct e1000e_tx *tx;
} E1000E_TxRing;

static inline int
e1000e_mq_queue_idx(int base_reg_idx, int reg_idx)
{
    return (reg_idx - base_reg_idx) / (0x100 >> 2);
}

static inline void
e1000e_tx_ring_init(E1000ECore *core, E1000E_TxRing *txr, int idx)
{
    static const E1000E_RingInfo i[E1000E_NUM_QUEUES] = {
        { TDBAH,  TDBAL,  TDLEN,  TDH,  TDT, 0 },
        { TDBAH1, TDBAL1, TDLEN1, TDH1, TDT1, 1 }
    };

    assert(idx < ARRAY_SIZE(i));

    txr->i     = &i[idx];
    txr->tx    = &core->tx[idx];
}

typedef struct E1000E_RxRing_st {
    const E1000E_RingInfo *i;
} E1000E_RxRing;

static inline void
e1000e_rx_ring_init(E1000ECore *core, E1000E_RxRing *rxr, int idx)
{
    static const E1000E_RingInfo i[E1000E_NUM_QUEUES] = {
        { RDBAH0, RDBAL0, RDLEN0, RDH0, RDT0, 0 },
        { RDBAH1, RDBAL1, RDLEN1, RDH1, RDT1, 1 }
    };

    assert(idx < ARRAY_SIZE(i));

    rxr->i      = &i[idx];
}

static void
e1000e_start_xmit(E1000ECore *core, const E1000E_TxRing *txr)
{
    dma_addr_t base;
    struct e1000_tx_desc desc;
    bool ide = false;
    const E1000E_RingInfo *txi = txr->i;
    uint32_t cause = E1000_ICS_TXQE;

    if (!(core->mac[TCTL] & E1000_TCTL_EN)) {
        trace_e1000e_tx_disabled();
        return;
    }

    while (!e1000e_ring_empty(core, txi)) {
        base = e1000e_ring_head_descr(core, txi);

        pci_dma_read(core->owner, base, &desc, sizeof(desc));

        trace_e1000e_tx_descr((void *)(intptr_t)desc.buffer_addr,
                              desc.lower.data, desc.upper.data);

        e1000e_process_tx_desc(core, txr->tx, &desc, txi->idx);
        cause |= e1000e_txdesc_writeback(core, base, &desc, &ide, txi->idx);

        e1000e_ring_advance(core, txi, 1);
    }

    if (!ide || !e1000e_intrmgr_delay_tx_causes(core, &cause)) {
        e1000e_set_interrupt_cause(core, cause);
    }
}

static bool
e1000e_has_rxbufs(E1000ECore *core, const E1000E_RingInfo *r,
                  size_t total_size)
{
    uint32_t bufs = e1000e_ring_free_descr_num(core, r);

    trace_e1000e_rx_has_buffers(r->idx, bufs, total_size,
                                core->rx_desc_buf_size);

    return total_size <= bufs / (core->rx_desc_len / E1000_MIN_RX_DESC_LEN) *
                         core->rx_desc_buf_size;
}

void
e1000e_start_recv(E1000ECore *core)
{
    int i;

    trace_e1000e_rx_start_recv();

    for (i = 0; i <= core->max_queue_num; i++) {
        qemu_flush_queued_packets(qemu_get_subqueue(core->owner_nic, i));
    }
}

bool
e1000e_can_receive(E1000ECore *core)
{
    int i;

    if (!e1000x_rx_ready(core->owner, core->mac)) {
        return false;
    }

    for (i = 0; i < E1000E_NUM_QUEUES; i++) {
        E1000E_RxRing rxr;

        e1000e_rx_ring_init(core, &rxr, i);
        if (e1000e_ring_enabled(core, rxr.i) &&
            e1000e_has_rxbufs(core, rxr.i, 1)) {
            trace_e1000e_rx_can_recv();
            return true;
        }
    }

    trace_e1000e_rx_can_recv_rings_full();
    return false;
}

ssize_t
e1000e_receive(E1000ECore *core, const uint8_t *buf, size_t size)
{
    const struct iovec iov = {
        .iov_base = (uint8_t *)buf,
        .iov_len = size
    };

    return e1000e_receive_iov(core, &iov, 1);
}

static inline bool

e1000e_rx_l3_cso_enabled(E1000ECore *core)
{
    return !!(core->mac[RXCSUM] & E1000_RXCSUM_IPOFLD);
}

static inline bool
e1000e_rx_l4_cso_enabled(E1000ECore *core)
{
    return !!(core->mac[RXCSUM] & E1000_RXCSUM_TUOFLD);
}

static bool
e1000e_receive_filter(E1000ECore *core, const uint8_t *buf, int size)
{
    uint32_t rctl = core->mac[RCTL];

    if (e1000x_is_vlan_packet(buf, core->mac[VET]) &&
        e1000x_vlan_rx_filter_enabled(core->mac)) {
        uint16_t vid = lduw_be_p(buf + 14);
        uint32_t vfta = ldl_le_p((uint32_t *)(core->mac + VFTA) +
                                 ((vid >> 5) & 0x7f));
        if ((vfta & (1 << (vid & 0x1f))) == 0) {
            trace_e1000e_rx_flt_vlan_mismatch(vid);
            return false;
        } else {
            trace_e1000e_rx_flt_vlan_match(vid);
        }
    }

    switch (net_rx_pkt_get_packet_type(core->rx_pkt)) {
    case ETH_PKT_UCAST:
        if (rctl & E1000_RCTL_UPE) {
            return true; /* promiscuous ucast */
        }
        break;

    case ETH_PKT_BCAST:
        if (rctl & E1000_RCTL_BAM) {
            return true; /* broadcast enabled */
        }
        break;

    case ETH_PKT_MCAST:
        if (rctl & E1000_RCTL_MPE) {
            return true; /* promiscuous mcast */
        }
        break;

    default:
        g_assert_not_reached();
    }

    return e1000x_rx_group_filter(core->mac, buf);
}

static inline void
e1000e_read_lgcy_rx_descr(E1000ECore *core, uint8_t *desc, hwaddr *buff_addr)
{
    struct e1000_rx_desc *d = (struct e1000_rx_desc *) desc;
    *buff_addr = le64_to_cpu(d->buffer_addr);
}

static inline void
e1000e_read_ext_rx_descr(E1000ECore *core, uint8_t *desc, hwaddr *buff_addr)
{
    union e1000_rx_desc_extended *d = (union e1000_rx_desc_extended *) desc;
    *buff_addr = le64_to_cpu(d->read.buffer_addr);
}

static inline void
e1000e_read_ps_rx_descr(E1000ECore *core, uint8_t *desc,
                        hwaddr (*buff_addr)[MAX_PS_BUFFERS])
{
    int i;
    union e1000_rx_desc_packet_split *d =
        (union e1000_rx_desc_packet_split *) desc;

    for (i = 0; i < MAX_PS_BUFFERS; i++) {
        (*buff_addr)[i] = le64_to_cpu(d->read.buffer_addr[i]);
    }

    trace_e1000e_rx_desc_ps_read((*buff_addr)[0], (*buff_addr)[1],
                                 (*buff_addr)[2], (*buff_addr)[3]);
}

static inline void
e1000e_read_rx_descr(E1000ECore *core, uint8_t *desc,
                     hwaddr (*buff_addr)[MAX_PS_BUFFERS])
{
    if (e1000e_rx_use_legacy_descriptor(core)) {
        e1000e_read_lgcy_rx_descr(core, desc, &(*buff_addr)[0]);
        (*buff_addr)[1] = (*buff_addr)[2] = (*buff_addr)[3] = 0;
    } else {
        if (core->mac[RCTL] & E1000_RCTL_DTYP_PS) {
            e1000e_read_ps_rx_descr(core, desc, buff_addr);
        } else {
            e1000e_read_ext_rx_descr(core, desc, &(*buff_addr)[0]);
            (*buff_addr)[1] = (*buff_addr)[2] = (*buff_addr)[3] = 0;
        }
    }
}

static void
e1000e_verify_csum_in_sw(E1000ECore *core,
                         struct NetRxPkt *pkt,
                         uint32_t *status_flags,
                         bool istcp, bool isudp)
{
    bool csum_valid;
    uint32_t csum_error;

    if (e1000e_rx_l3_cso_enabled(core)) {
        if (!net_rx_pkt_validate_l3_csum(pkt, &csum_valid)) {
            trace_e1000e_rx_metadata_l3_csum_validation_failed();
        } else {
            csum_error = csum_valid ? 0 : E1000_RXDEXT_STATERR_IPE;
            *status_flags |= E1000_RXD_STAT_IPCS | csum_error;
        }
    } else {
        trace_e1000e_rx_metadata_l3_cso_disabled();
    }

    if (!e1000e_rx_l4_cso_enabled(core)) {
        trace_e1000e_rx_metadata_l4_cso_disabled();
        return;
    }

    if (!net_rx_pkt_validate_l4_csum(pkt, &csum_valid)) {
        trace_e1000e_rx_metadata_l4_csum_validation_failed();
        return;
    }

    csum_error = csum_valid ? 0 : E1000_RXDEXT_STATERR_TCPE;

    if (istcp) {
        *status_flags |= E1000_RXD_STAT_TCPCS |
                         csum_error;
    } else if (isudp) {
        *status_flags |= E1000_RXD_STAT_TCPCS |
                         E1000_RXD_STAT_UDPCS |
                         csum_error;
    }
}

static inline bool
e1000e_is_tcp_ack(E1000ECore *core, struct NetRxPkt *rx_pkt)
{
    if (!net_rx_pkt_is_tcp_ack(rx_pkt)) {
        return false;
    }

    if (core->mac[RFCTL] & E1000_RFCTL_ACK_DATA_DIS) {
        return !net_rx_pkt_has_tcp_data(rx_pkt);
    }

    return true;
}

static void
e1000e_build_rx_metadata(E1000ECore *core,
                         struct NetRxPkt *pkt,
                         bool is_eop,
                         const E1000E_RSSInfo *rss_info,
                         uint32_t *rss, uint32_t *mrq,
                         uint32_t *status_flags,
                         uint16_t *ip_id,
                         uint16_t *vlan_tag)
{
    struct virtio_net_hdr *vhdr;
    bool isip4, isip6, istcp, isudp;
    uint32_t pkt_type;

    *status_flags = E1000_RXD_STAT_DD;

    /* No additional metadata needed for non-EOP descriptors */
    if (!is_eop) {
        goto func_exit;
    }

    *status_flags |= E1000_RXD_STAT_EOP;

    net_rx_pkt_get_protocols(pkt, &isip4, &isip6, &isudp, &istcp);
    trace_e1000e_rx_metadata_protocols(isip4, isip6, isudp, istcp);

    /* VLAN state */
    if (net_rx_pkt_is_vlan_stripped(pkt)) {
        *status_flags |= E1000_RXD_STAT_VP;
        *vlan_tag = cpu_to_le16(net_rx_pkt_get_vlan_tag(pkt));
        trace_e1000e_rx_metadata_vlan(*vlan_tag);
    }

    /* Packet parsing results */
    if ((core->mac[RXCSUM] & E1000_RXCSUM_PCSD) != 0) {
        if (rss_info->enabled) {
            *rss = cpu_to_le32(rss_info->hash);
            *mrq = cpu_to_le32(rss_info->type | (rss_info->queue << 8));
            trace_e1000e_rx_metadata_rss(*rss, *mrq);
        }
    } else if (isip4) {
            *status_flags |= E1000_RXD_STAT_IPIDV;
            *ip_id = cpu_to_le16(net_rx_pkt_get_ip_id(pkt));
            trace_e1000e_rx_metadata_ip_id(*ip_id);
    }

    if (istcp && e1000e_is_tcp_ack(core, pkt)) {
        *status_flags |= E1000_RXD_STAT_ACK;
        trace_e1000e_rx_metadata_ack();
    }

    if (isip6 && (core->mac[RFCTL] & E1000_RFCTL_IPV6_DIS)) {
        trace_e1000e_rx_metadata_ipv6_filtering_disabled();
        pkt_type = E1000_RXD_PKT_MAC;
    } else if (istcp || isudp) {
        pkt_type = isip4 ? E1000_RXD_PKT_IP4_XDP : E1000_RXD_PKT_IP6_XDP;
    } else if (isip4 || isip6) {
        pkt_type = isip4 ? E1000_RXD_PKT_IP4 : E1000_RXD_PKT_IP6;
    } else {
        pkt_type = E1000_RXD_PKT_MAC;
    }

    *status_flags |= E1000_RXD_PKT_TYPE(pkt_type);
    trace_e1000e_rx_metadata_pkt_type(pkt_type);

    /* RX CSO information */
    if (isip6 && (core->mac[RFCTL] & E1000_RFCTL_IPV6_XSUM_DIS)) {
        trace_e1000e_rx_metadata_ipv6_sum_disabled();
        goto func_exit;
    }

    if (!net_rx_pkt_has_virt_hdr(pkt)) {
        trace_e1000e_rx_metadata_no_virthdr();
        e1000e_verify_csum_in_sw(core, pkt, status_flags, istcp, isudp);
        goto func_exit;
    }

    vhdr = net_rx_pkt_get_vhdr(pkt);

    if (!(vhdr->flags & VIRTIO_NET_HDR_F_DATA_VALID) &&
        !(vhdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM)) {
        trace_e1000e_rx_metadata_virthdr_no_csum_info();
        e1000e_verify_csum_in_sw(core, pkt, status_flags, istcp, isudp);
        goto func_exit;
    }

    if (e1000e_rx_l3_cso_enabled(core)) {
        *status_flags |= isip4 ? E1000_RXD_STAT_IPCS : 0;
    } else {
        trace_e1000e_rx_metadata_l3_cso_disabled();
    }

    if (e1000e_rx_l4_cso_enabled(core)) {
        if (istcp) {
            *status_flags |= E1000_RXD_STAT_TCPCS;
        } else if (isudp) {
            *status_flags |= E1000_RXD_STAT_TCPCS | E1000_RXD_STAT_UDPCS;
        }
    } else {
        trace_e1000e_rx_metadata_l4_cso_disabled();
    }

    trace_e1000e_rx_metadata_status_flags(*status_flags);

func_exit:
    *status_flags = cpu_to_le32(*status_flags);
}

static inline void
e1000e_write_lgcy_rx_descr(E1000ECore *core, uint8_t *desc,
                           struct NetRxPkt *pkt,
                           const E1000E_RSSInfo *rss_info,
                           uint16_t length)
{
    uint32_t status_flags, rss, mrq;
    uint16_t ip_id;

    struct e1000_rx_desc *d = (struct e1000_rx_desc *) desc;

    assert(!rss_info->enabled);

    d->length = cpu_to_le16(length);
    d->csum = 0;

    e1000e_build_rx_metadata(core, pkt, pkt != NULL,
                             rss_info,
                             &rss, &mrq,
                             &status_flags, &ip_id,
                             &d->special);
    d->errors = (uint8_t) (le32_to_cpu(status_flags) >> 24);
    d->status = (uint8_t) le32_to_cpu(status_flags);
}

static inline void
e1000e_write_ext_rx_descr(E1000ECore *core, uint8_t *desc,
                          struct NetRxPkt *pkt,
                          const E1000E_RSSInfo *rss_info,
                          uint16_t length)
{
    union e1000_rx_desc_extended *d = (union e1000_rx_desc_extended *) desc;

    memset(&d->wb, 0, sizeof(d->wb));

    d->wb.upper.length = cpu_to_le16(length);

    e1000e_build_rx_metadata(core, pkt, pkt != NULL,
                             rss_info,
                             &d->wb.lower.hi_dword.rss,
                             &d->wb.lower.mrq,
                             &d->wb.upper.status_error,
                             &d->wb.lower.hi_dword.csum_ip.ip_id,
                             &d->wb.upper.vlan);
}

static inline void
e1000e_write_ps_rx_descr(E1000ECore *core, uint8_t *desc,
                         struct NetRxPkt *pkt,
                         const E1000E_RSSInfo *rss_info,
                         size_t ps_hdr_len,
                         uint16_t(*written)[MAX_PS_BUFFERS])
{
    int i;
    union e1000_rx_desc_packet_split *d =
        (union e1000_rx_desc_packet_split *) desc;

    memset(&d->wb, 0, sizeof(d->wb));

    d->wb.middle.length0 = cpu_to_le16((*written)[0]);

    for (i = 0; i < PS_PAGE_BUFFERS; i++) {
        d->wb.upper.length[i] = cpu_to_le16((*written)[i + 1]);
    }

    e1000e_build_rx_metadata(core, pkt, pkt != NULL,
                             rss_info,
                             &d->wb.lower.hi_dword.rss,
                             &d->wb.lower.mrq,
                             &d->wb.middle.status_error,
                             &d->wb.lower.hi_dword.csum_ip.ip_id,
                             &d->wb.middle.vlan);

    d->wb.upper.header_status =
        cpu_to_le16(ps_hdr_len | (ps_hdr_len ? E1000_RXDPS_HDRSTAT_HDRSP : 0));

    trace_e1000e_rx_desc_ps_write((*written)[0], (*written)[1],
                                  (*written)[2], (*written)[3]);
}

static inline void
e1000e_write_rx_descr(E1000ECore *core, uint8_t *desc,
struct NetRxPkt *pkt, const E1000E_RSSInfo *rss_info,
    size_t ps_hdr_len, uint16_t(*written)[MAX_PS_BUFFERS])
{
    if (e1000e_rx_use_legacy_descriptor(core)) {
        assert(ps_hdr_len == 0);
        e1000e_write_lgcy_rx_descr(core, desc, pkt, rss_info, (*written)[0]);
    } else {
        if (core->mac[RCTL] & E1000_RCTL_DTYP_PS) {
            e1000e_write_ps_rx_descr(core, desc, pkt, rss_info,
                                      ps_hdr_len, written);
        } else {
            assert(ps_hdr_len == 0);
            e1000e_write_ext_rx_descr(core, desc, pkt, rss_info,
                                       (*written)[0]);
        }
    }
}

typedef struct e1000e_ba_state_st {
    uint16_t written[MAX_PS_BUFFERS];
    uint8_t cur_idx;
} e1000e_ba_state;

static inline void
e1000e_write_hdr_to_rx_buffers(E1000ECore *core,
                               hwaddr (*ba)[MAX_PS_BUFFERS],
                               e1000e_ba_state *bastate,
                               const char *data,
                               dma_addr_t data_len)
{
    assert(data_len <= core->rxbuf_sizes[0] - bastate->written[0]);

    pci_dma_write(core->owner, (*ba)[0] + bastate->written[0], data, data_len);
    bastate->written[0] += data_len;

    bastate->cur_idx = 1;
}

static void
e1000e_write_to_rx_buffers(E1000ECore *core,
                           hwaddr (*ba)[MAX_PS_BUFFERS],
                           e1000e_ba_state *bastate,
                           const char *data,
                           dma_addr_t data_len)
{
    while (data_len > 0) {
        uint32_t cur_buf_len = core->rxbuf_sizes[bastate->cur_idx];
        uint32_t cur_buf_bytes_left = cur_buf_len -
                                      bastate->written[bastate->cur_idx];
        uint32_t bytes_to_write = MIN(data_len, cur_buf_bytes_left);

        trace_e1000e_rx_desc_buff_write(bastate->cur_idx,
                                        (*ba)[bastate->cur_idx],
                                        bastate->written[bastate->cur_idx],
                                        data,
                                        bytes_to_write);

        pci_dma_write(core->owner,
            (*ba)[bastate->cur_idx] + bastate->written[bastate->cur_idx],
            data, bytes_to_write);

        bastate->written[bastate->cur_idx] += bytes_to_write;
        data += bytes_to_write;
        data_len -= bytes_to_write;

        if (bastate->written[bastate->cur_idx] == cur_buf_len) {
            bastate->cur_idx++;
        }

        assert(bastate->cur_idx < MAX_PS_BUFFERS);
    }
}

static void
e1000e_update_rx_stats(E1000ECore *core,
                       size_t data_size,
                       size_t data_fcs_size)
{
    e1000x_update_rx_total_stats(core->mac, data_size, data_fcs_size);

    switch (net_rx_pkt_get_packet_type(core->rx_pkt)) {
    case ETH_PKT_BCAST:
        e1000x_inc_reg_if_not_full(core->mac, BPRC);
        break;

    case ETH_PKT_MCAST:
        e1000x_inc_reg_if_not_full(core->mac, MPRC);
        break;

    default:
        break;
    }
}

static inline bool
e1000e_rx_descr_threshold_hit(E1000ECore *core, const E1000E_RingInfo *rxi)
{
    return e1000e_ring_free_descr_num(core, rxi) ==
           e1000e_ring_len(core, rxi) >> core->rxbuf_min_shift;
}

static bool
e1000e_do_ps(E1000ECore *core, struct NetRxPkt *pkt, size_t *hdr_len)
{
    bool isip4, isip6, isudp, istcp;
    bool fragment;

    if (!e1000e_rx_use_ps_descriptor(core)) {
        return false;
    }

    net_rx_pkt_get_protocols(pkt, &isip4, &isip6, &isudp, &istcp);

    if (isip4) {
        fragment = net_rx_pkt_get_ip4_info(pkt)->fragment;
    } else if (isip6) {
        fragment = net_rx_pkt_get_ip6_info(pkt)->fragment;
    } else {
        return false;
    }

    if (fragment && (core->mac[RFCTL] & E1000_RFCTL_IPFRSP_DIS)) {
        return false;
    }

    if (!fragment && (isudp || istcp)) {
        *hdr_len = net_rx_pkt_get_l5_hdr_offset(pkt);
    } else {
        *hdr_len = net_rx_pkt_get_l4_hdr_offset(pkt);
    }

    if ((*hdr_len > core->rxbuf_sizes[0]) ||
        (*hdr_len > net_rx_pkt_get_total_len(pkt))) {
        return false;
    }

    return true;
}

static void
e1000e_write_packet_to_guest(E1000ECore *core, struct NetRxPkt *pkt,
                             const E1000E_RxRing *rxr,
                             const E1000E_RSSInfo *rss_info)
{
    PCIDevice *d = core->owner;
    dma_addr_t base;
    uint8_t desc[E1000_MAX_RX_DESC_LEN];
    size_t desc_size;
    size_t desc_offset = 0;
    size_t iov_ofs = 0;

    struct iovec *iov = net_rx_pkt_get_iovec(pkt);
    size_t size = net_rx_pkt_get_total_len(pkt);
    size_t total_size = size + e1000x_fcs_len(core->mac);
    const E1000E_RingInfo *rxi;
    size_t ps_hdr_len = 0;
    bool do_ps = e1000e_do_ps(core, pkt, &ps_hdr_len);
    bool is_first = true;

    rxi = rxr->i;

    do {
        hwaddr ba[MAX_PS_BUFFERS];
        e1000e_ba_state bastate = { { 0 } };
        bool is_last = false;

        desc_size = total_size - desc_offset;

        if (desc_size > core->rx_desc_buf_size) {
            desc_size = core->rx_desc_buf_size;
        }

        if (e1000e_ring_empty(core, rxi)) {
            return;
        }

        base = e1000e_ring_head_descr(core, rxi);

        pci_dma_read(d, base, &desc, core->rx_desc_len);

        trace_e1000e_rx_descr(rxi->idx, base, core->rx_desc_len);

        e1000e_read_rx_descr(core, desc, &ba);

        if (ba[0]) {
            if (desc_offset < size) {
                static const uint32_t fcs_pad;
                size_t iov_copy;
                size_t copy_size = size - desc_offset;
                if (copy_size > core->rx_desc_buf_size) {
                    copy_size = core->rx_desc_buf_size;
                }

                /* For PS mode copy the packet header first */
                if (do_ps) {
                    if (is_first) {
                        size_t ps_hdr_copied = 0;
                        do {
                            iov_copy = MIN(ps_hdr_len - ps_hdr_copied,
                                           iov->iov_len - iov_ofs);

                            e1000e_write_hdr_to_rx_buffers(core, &ba, &bastate,
                                                      iov->iov_base, iov_copy);

                            copy_size -= iov_copy;
                            ps_hdr_copied += iov_copy;

                            iov_ofs += iov_copy;
                            if (iov_ofs == iov->iov_len) {
                                iov++;
                                iov_ofs = 0;
                            }
                        } while (ps_hdr_copied < ps_hdr_len);

                        is_first = false;
                    } else {
                        /* Leave buffer 0 of each descriptor except first */
                        /* empty as per spec 7.1.5.1                      */
                        e1000e_write_hdr_to_rx_buffers(core, &ba, &bastate,
                                                       NULL, 0);
                    }
                }

                /* Copy packet payload */
                while (copy_size) {
                    iov_copy = MIN(copy_size, iov->iov_len - iov_ofs);

                    e1000e_write_to_rx_buffers(core, &ba, &bastate,
                                            iov->iov_base + iov_ofs, iov_copy);

                    copy_size -= iov_copy;
                    iov_ofs += iov_copy;
                    if (iov_ofs == iov->iov_len) {
                        iov++;
                        iov_ofs = 0;
                    }
                }

                if (desc_offset + desc_size >= total_size) {
                    /* Simulate FCS checksum presence in the last descriptor */
                    e1000e_write_to_rx_buffers(core, &ba, &bastate,
                          (const char *) &fcs_pad, e1000x_fcs_len(core->mac));
                }
            }
        } else { /* as per intel docs; skip descriptors with null buf addr */
            trace_e1000e_rx_null_descriptor();
        }
        desc_offset += desc_size;
        if (desc_offset >= total_size) {
            is_last = true;
        }

        e1000e_write_rx_descr(core, desc, is_last ? core->rx_pkt : NULL,
                           rss_info, do_ps ? ps_hdr_len : 0, &bastate.written);
        pci_dma_write(d, base, &desc, core->rx_desc_len);

        e1000e_ring_advance(core, rxi,
                            core->rx_desc_len / E1000_MIN_RX_DESC_LEN);

    } while (desc_offset < total_size);

    e1000e_update_rx_stats(core, size, total_size);
}

static inline void
e1000e_rx_fix_l4_csum(E1000ECore *core, struct NetRxPkt *pkt)
{
    if (net_rx_pkt_has_virt_hdr(pkt)) {
        struct virtio_net_hdr *vhdr = net_rx_pkt_get_vhdr(pkt);

        if (vhdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
            net_rx_pkt_fix_l4_csum(pkt);
        }
    }
}

ssize_t
e1000e_receive_iov(E1000ECore *core, const struct iovec *iov, int iovcnt)
{
    static const int maximum_ethernet_hdr_len = (14 + 4);
    /* Min. octets in an ethernet frame sans FCS */
    static const int min_buf_size = 60;

    uint32_t n = 0;
    uint8_t min_buf[min_buf_size];
    struct iovec min_iov;
    uint8_t *filter_buf;
    size_t size, orig_size;
    size_t iov_ofs = 0;
    E1000E_RxRing rxr;
    E1000E_RSSInfo rss_info;
    size_t total_size;
    ssize_t retval;
    bool rdmts_hit;

    trace_e1000e_rx_receive_iov(iovcnt);

    if (!e1000x_hw_rx_enabled(core->mac)) {
        return -1;
    }

    /* Pull virtio header in */
    if (core->has_vnet) {
        net_rx_pkt_set_vhdr_iovec(core->rx_pkt, iov, iovcnt);
        iov_ofs = sizeof(struct virtio_net_hdr);
    }

    filter_buf = iov->iov_base + iov_ofs;
    orig_size = iov_size(iov, iovcnt);
    size = orig_size - iov_ofs;

    /* Pad to minimum Ethernet frame length */
    if (size < sizeof(min_buf)) {
        iov_to_buf(iov, iovcnt, iov_ofs, min_buf, size);
        memset(&min_buf[size], 0, sizeof(min_buf) - size);
        e1000x_inc_reg_if_not_full(core->mac, RUC);
        min_iov.iov_base = filter_buf = min_buf;
        min_iov.iov_len = size = sizeof(min_buf);
        iovcnt = 1;
        iov = &min_iov;
        iov_ofs = 0;
    } else if (iov->iov_len < maximum_ethernet_hdr_len) {
        /* This is very unlikely, but may happen. */
        iov_to_buf(iov, iovcnt, iov_ofs, min_buf, maximum_ethernet_hdr_len);
        filter_buf = min_buf;
    }

    /* Discard oversized packets if !LPE and !SBP. */
    if (e1000x_is_oversized(core->mac, size)) {
        return orig_size;
    }

    net_rx_pkt_set_packet_type(core->rx_pkt,
        get_eth_packet_type(PKT_GET_ETH_HDR(filter_buf)));

    if (!e1000e_receive_filter(core, filter_buf, size)) {
        trace_e1000e_rx_flt_dropped();
        return orig_size;
    }

    net_rx_pkt_attach_iovec_ex(core->rx_pkt, iov, iovcnt, iov_ofs,
                               e1000x_vlan_enabled(core->mac), core->mac[VET]);

    e1000e_rss_parse_packet(core, core->rx_pkt, &rss_info);
    e1000e_rx_ring_init(core, &rxr, rss_info.queue);

    trace_e1000e_rx_rss_dispatched_to_queue(rxr.i->idx);

    total_size = net_rx_pkt_get_total_len(core->rx_pkt) +
        e1000x_fcs_len(core->mac);

    if (e1000e_has_rxbufs(core, rxr.i, total_size)) {
        e1000e_rx_fix_l4_csum(core, core->rx_pkt);

        e1000e_write_packet_to_guest(core, core->rx_pkt, &rxr, &rss_info);

        retval = orig_size;

        /* Perform small receive detection (RSRPD) */
        if (total_size < core->mac[RSRPD]) {
            n |= E1000_ICS_SRPD;
        }

        /* Perform ACK receive detection */
        if  (!(core->mac[RFCTL] & E1000_RFCTL_ACK_DIS) &&
             (e1000e_is_tcp_ack(core, core->rx_pkt))) {
            n |= E1000_ICS_ACK;
        }

        /* Check if receive descriptor minimum threshold hit */
        rdmts_hit = e1000e_rx_descr_threshold_hit(core, rxr.i);
        n |= e1000e_rx_wb_interrupt_cause(core, rxr.i->idx, rdmts_hit);

        trace_e1000e_rx_written_to_guest(n);
    } else {
        n |= E1000_ICS_RXO;
        retval = 0;

        trace_e1000e_rx_not_written_to_guest(n);
    }

    if (!e1000e_intrmgr_delay_rx_causes(core, &n)) {
        trace_e1000e_rx_interrupt_set(n);
        e1000e_set_interrupt_cause(core, n);
    } else {
        trace_e1000e_rx_interrupt_delayed(n);
    }

    return retval;
}

static inline bool
e1000e_have_autoneg(E1000ECore *core)
{
    return core->phy[0][PHY_CTRL] & MII_CR_AUTO_NEG_EN;
}

static void e1000e_update_flowctl_status(E1000ECore *core)
{
    if (e1000e_have_autoneg(core) &&
        core->phy[0][PHY_STATUS] & MII_SR_AUTONEG_COMPLETE) {
        trace_e1000e_link_autoneg_flowctl(true);
        core->mac[CTRL] |= E1000_CTRL_TFCE | E1000_CTRL_RFCE;
    } else {
        trace_e1000e_link_autoneg_flowctl(false);
    }
}

static inline void
e1000e_link_down(E1000ECore *core)
{
    e1000x_update_regs_on_link_down(core->mac, core->phy[0]);
    e1000e_update_flowctl_status(core);
}

static inline void
e1000e_set_phy_ctrl(E1000ECore *core, int index, uint16_t val)
{
    /* bits 0-5 reserved; MII_CR_[RESTART_AUTO_NEG,RESET] are self clearing */
    core->phy[0][PHY_CTRL] = val & ~(0x3f |
                                     MII_CR_RESET |
                                     MII_CR_RESTART_AUTO_NEG);

    if ((val & MII_CR_RESTART_AUTO_NEG) &&
        e1000e_have_autoneg(core)) {
        e1000x_restart_autoneg(core->mac, core->phy[0], core->autoneg_timer);
    }
}

static void
e1000e_set_phy_oem_bits(E1000ECore *core, int index, uint16_t val)
{
    core->phy[0][PHY_OEM_BITS] = val & ~BIT(10);

    if (val & BIT(10)) {
        e1000x_restart_autoneg(core->mac, core->phy[0], core->autoneg_timer);
    }
}

static void
e1000e_set_phy_page(E1000ECore *core, int index, uint16_t val)
{
    core->phy[0][PHY_PAGE] = val & PHY_PAGE_RW_MASK;
}

void
e1000e_core_set_link_status(E1000ECore *core)
{
    NetClientState *nc = qemu_get_queue(core->owner_nic);
    uint32_t old_status = core->mac[STATUS];

    trace_e1000e_link_status_changed(nc->link_down ? false : true);

    if (nc->link_down) {
        e1000x_update_regs_on_link_down(core->mac, core->phy[0]);
    } else {
        if (e1000e_have_autoneg(core) &&
            !(core->phy[0][PHY_STATUS] & MII_SR_AUTONEG_COMPLETE)) {
            e1000x_restart_autoneg(core->mac, core->phy[0],
                                   core->autoneg_timer);
        } else {
            e1000x_update_regs_on_link_up(core->mac, core->phy[0]);
            e1000e_start_recv(core);
        }
    }

    if (core->mac[STATUS] != old_status) {
        e1000e_set_interrupt_cause(core, E1000_ICR_LSC);
    }
}

static void
e1000e_set_ctrl(E1000ECore *core, int index, uint32_t val)
{
    trace_e1000e_core_ctrl_write(index, val);

    /* RST is self clearing */
    core->mac[CTRL] = val & ~E1000_CTRL_RST;
    core->mac[CTRL_DUP] = core->mac[CTRL];

    trace_e1000e_link_set_params(
        !!(val & E1000_CTRL_ASDE),
        (val & E1000_CTRL_SPD_SEL) >> E1000_CTRL_SPD_SHIFT,
        !!(val & E1000_CTRL_FRCSPD),
        !!(val & E1000_CTRL_FRCDPX),
        !!(val & E1000_CTRL_RFCE),
        !!(val & E1000_CTRL_TFCE));

    if (val & E1000_CTRL_RST) {
        trace_e1000e_core_ctrl_sw_reset();
        e1000x_reset_mac_addr(core->owner_nic, core->mac, core->permanent_mac);
    }

    if (val & E1000_CTRL_PHY_RST) {
        trace_e1000e_core_ctrl_phy_reset();
        core->mac[STATUS] |= E1000_STATUS_PHYRA;
    }
}

static void
e1000e_set_rfctl(E1000ECore *core, int index, uint32_t val)
{
    trace_e1000e_rx_set_rfctl(val);

    if (!(val & E1000_RFCTL_ISCSI_DIS)) {
        trace_e1000e_wrn_iscsi_filtering_not_supported();
    }

    if (!(val & E1000_RFCTL_NFSW_DIS)) {
        trace_e1000e_wrn_nfsw_filtering_not_supported();
    }

    if (!(val & E1000_RFCTL_NFSR_DIS)) {
        trace_e1000e_wrn_nfsr_filtering_not_supported();
    }

    core->mac[RFCTL] = val;
}

static void
e1000e_calc_per_desc_buf_size(E1000ECore *core)
{
    int i;
    core->rx_desc_buf_size = 0;

    for (i = 0; i < ARRAY_SIZE(core->rxbuf_sizes); i++) {
        core->rx_desc_buf_size += core->rxbuf_sizes[i];
    }
}

static void
e1000e_parse_rxbufsize(E1000ECore *core)
{
    uint32_t rctl = core->mac[RCTL];

    memset(core->rxbuf_sizes, 0, sizeof(core->rxbuf_sizes));

    if (rctl & E1000_RCTL_DTYP_MASK) {
        uint32_t bsize;

        bsize = core->mac[PSRCTL] & E1000_PSRCTL_BSIZE0_MASK;
        core->rxbuf_sizes[0] = (bsize >> E1000_PSRCTL_BSIZE0_SHIFT) * 128;

        bsize = core->mac[PSRCTL] & E1000_PSRCTL_BSIZE1_MASK;
        core->rxbuf_sizes[1] = (bsize >> E1000_PSRCTL_BSIZE1_SHIFT) * 1024;

        bsize = core->mac[PSRCTL] & E1000_PSRCTL_BSIZE2_MASK;
        core->rxbuf_sizes[2] = (bsize >> E1000_PSRCTL_BSIZE2_SHIFT) * 1024;

        bsize = core->mac[PSRCTL] & E1000_PSRCTL_BSIZE3_MASK;
        core->rxbuf_sizes[3] = (bsize >> E1000_PSRCTL_BSIZE3_SHIFT) * 1024;
    } else if (rctl & E1000_RCTL_FLXBUF_MASK) {
        int flxbuf = rctl & E1000_RCTL_FLXBUF_MASK;
        core->rxbuf_sizes[0] = (flxbuf >> E1000_RCTL_FLXBUF_SHIFT) * 1024;
    } else {
        core->rxbuf_sizes[0] = e1000x_rxbufsize(rctl);
    }

    trace_e1000e_rx_desc_buff_sizes(core->rxbuf_sizes[0], core->rxbuf_sizes[1],
                                    core->rxbuf_sizes[2], core->rxbuf_sizes[3]);

    e1000e_calc_per_desc_buf_size(core);
}

static void
e1000e_calc_rxdesclen(E1000ECore *core)
{
    if (e1000e_rx_use_legacy_descriptor(core)) {
        core->rx_desc_len = sizeof(struct e1000_rx_desc);
    } else {
        if (core->mac[RCTL] & E1000_RCTL_DTYP_PS) {
            core->rx_desc_len = sizeof(union e1000_rx_desc_packet_split);
        } else {
            core->rx_desc_len = sizeof(union e1000_rx_desc_extended);
        }
    }
    trace_e1000e_rx_desc_len(core->rx_desc_len);
}

static void
e1000e_set_rx_control(E1000ECore *core, int index, uint32_t val)
{
    core->mac[RCTL] = val;
    trace_e1000e_rx_set_rctl(core->mac[RCTL]);

    if (val & E1000_RCTL_EN) {
        e1000e_parse_rxbufsize(core);
        e1000e_calc_rxdesclen(core);
        core->rxbuf_min_shift = ((val / E1000_RCTL_RDMTS_QUAT) & 3) + 1 +
                                E1000_RING_DESC_LEN_SHIFT;

        e1000e_start_recv(core);
    }
}

static
void(*e1000e_phyreg_writeops[E1000E_PHY_PAGES][E1000E_PHY_PAGE_SIZE])
(E1000ECore *, int, uint16_t) = {
    [0] = {
        [PHY_CTRL]     = e1000e_set_phy_ctrl,
        [PHY_PAGE]     = e1000e_set_phy_page,
        [PHY_OEM_BITS] = e1000e_set_phy_oem_bits
    }
};

static inline void
e1000e_clear_ims_bits(E1000ECore *core, uint32_t bits)
{
    trace_e1000e_irq_clear_ims(bits, core->mac[IMS], core->mac[IMS] & ~bits);
    core->mac[IMS] &= ~bits;
}

static inline bool
e1000e_postpone_interrupt(bool *interrupt_pending,
                           E1000IntrDelayTimer *timer)
{
    if (timer->running) {
        trace_e1000e_irq_postponed_by_xitr(timer->delay_reg << 2);

        *interrupt_pending = true;
        return true;
    }

    if (timer->core->mac[timer->delay_reg] != 0) {
        e1000e_intrmgr_rearm_timer(timer);
    }

    return false;
}

static inline bool
e1000e_itr_should_postpone(E1000ECore *core)
{
    return e1000e_postpone_interrupt(&core->itr_intr_pending, &core->itr);
}

static inline bool
e1000e_eitr_should_postpone(E1000ECore *core, int idx)
{
    return e1000e_postpone_interrupt(&core->eitr_intr_pending[idx],
                                     &core->eitr[idx]);
}

static void
e1000e_msix_notify_one(E1000ECore *core, uint32_t cause, uint32_t int_cfg)
{
    uint32_t effective_eiac;

    if (E1000_IVAR_ENTRY_VALID(int_cfg)) {
        uint32_t vec = E1000_IVAR_ENTRY_VEC(int_cfg);
        if (vec < E1000E_MSIX_VEC_NUM) {
            if (!e1000e_eitr_should_postpone(core, vec)) {

                trace_e1000e_irq_msix_notify_vec(vec);
                msix_notify(core->owner, vec);
            }
        } else {
            trace_e1000e_wrn_msix_vec_wrong(cause, int_cfg);
        }
    } else {
        trace_e1000e_wrn_msix_invalid(cause, int_cfg);
    }

    if (core->mac[CTRL_EXT] & E1000_CTRL_EXT_EIAME) {
        trace_e1000e_irq_iam_clear_eiame(core->mac[IAM], cause);
        core->mac[IAM] &= ~cause;
    }

    trace_e1000e_irq_icr_clear_eiac(core->mac[ICR], core->mac[EIAC]);

    effective_eiac = core->mac[EIAC] & cause;

    core->mac[ICR] &= ~effective_eiac;
    core->msi_causes_pending &= ~effective_eiac;

    if (!(core->mac[CTRL_EXT] & E1000_CTRL_EXT_IAME)) {
        core->mac[IMS] &= ~effective_eiac;
    }
}

static void
e1000e_msix_notify(E1000ECore *core, uint32_t causes)
{
    if (causes & E1000_ICR_RXQ0) {
        e1000e_msix_notify_one(core, E1000_ICR_RXQ0,
                               E1000_IVAR_RXQ0(core->mac[IVAR]));
    }

    if (causes & E1000_ICR_RXQ1) {
        e1000e_msix_notify_one(core, E1000_ICR_RXQ1,
                               E1000_IVAR_RXQ1(core->mac[IVAR]));
    }

    if (causes & E1000_ICR_TXQ0) {
        e1000e_msix_notify_one(core, E1000_ICR_TXQ0,
                               E1000_IVAR_TXQ0(core->mac[IVAR]));
    }

    if (causes & E1000_ICR_TXQ1) {
        e1000e_msix_notify_one(core, E1000_ICR_TXQ1,
                               E1000_IVAR_TXQ1(core->mac[IVAR]));
    }

    if (causes & E1000_ICR_OTHER) {
        e1000e_msix_notify_one(core, E1000_ICR_OTHER,
                               E1000_IVAR_OTHER(core->mac[IVAR]));
    }
}

static void
e1000e_msix_clear_one(E1000ECore *core, uint32_t cause, uint32_t int_cfg)
{
    if (E1000_IVAR_ENTRY_VALID(int_cfg)) {
        uint32_t vec = E1000_IVAR_ENTRY_VEC(int_cfg);
        if (vec < E1000E_MSIX_VEC_NUM) {
            trace_e1000e_irq_msix_pending_clearing(cause, int_cfg, vec);
            msix_clr_pending(core->owner, vec);
        } else {
            trace_e1000e_wrn_msix_vec_wrong(cause, int_cfg);
        }
    } else {
        trace_e1000e_wrn_msix_invalid(cause, int_cfg);
    }
}

static void
e1000e_msix_clear(E1000ECore *core, uint32_t causes)
{
    if (causes & E1000_ICR_RXQ0) {
        e1000e_msix_clear_one(core, E1000_ICR_RXQ0,
                              E1000_IVAR_RXQ0(core->mac[IVAR]));
    }

    if (causes & E1000_ICR_RXQ1) {
        e1000e_msix_clear_one(core, E1000_ICR_RXQ1,
                              E1000_IVAR_RXQ1(core->mac[IVAR]));
    }

    if (causes & E1000_ICR_TXQ0) {
        e1000e_msix_clear_one(core, E1000_ICR_TXQ0,
                              E1000_IVAR_TXQ0(core->mac[IVAR]));
    }

    if (causes & E1000_ICR_TXQ1) {
        e1000e_msix_clear_one(core, E1000_ICR_TXQ1,
                              E1000_IVAR_TXQ1(core->mac[IVAR]));
    }

    if (causes & E1000_ICR_OTHER) {
        e1000e_msix_clear_one(core, E1000_ICR_OTHER,
                              E1000_IVAR_OTHER(core->mac[IVAR]));
    }
}

static inline void
e1000e_fix_icr_asserted(E1000ECore *core)
{
    core->mac[ICR] &= ~E1000_ICR_ASSERTED;
    if (core->mac[ICR]) {
        core->mac[ICR] |= E1000_ICR_ASSERTED;
    }

    trace_e1000e_irq_fix_icr_asserted(core->mac[ICR]);
}

static void
e1000e_send_msi(E1000ECore *core, bool msix)
{
    uint32_t causes = core->mac[ICR] & core->mac[IMS] & ~E1000_ICR_ASSERTED;

    core->msi_causes_pending &= causes;
    causes ^= core->msi_causes_pending;
    if (causes == 0) {
        return;
    }
    core->msi_causes_pending |= causes;

    if (msix) {
        e1000e_msix_notify(core, causes);
    } else {
        if (!e1000e_itr_should_postpone(core)) {
            trace_e1000e_irq_msi_notify(causes);
            msi_notify(core->owner, 0);
        }
    }
}

static void
e1000e_update_interrupt_state(E1000ECore *core)
{
    bool interrupts_pending;
    bool is_msix = msix_enabled(core->owner);

    /* Set ICR[OTHER] for MSI-X */
    if (is_msix) {
        if (core->mac[ICR] & E1000_ICR_OTHER_CAUSES) {
            core->mac[ICR] |= E1000_ICR_OTHER;
            trace_e1000e_irq_add_msi_other(core->mac[ICR]);
        }
    }

    e1000e_fix_icr_asserted(core);

    /*
     * Make sure ICR and ICS registers have the same value.
     * The spec says that the ICS register is write-only.  However in practice,
     * on real hardware ICS is readable, and for reads it has the same value as
     * ICR (except that ICS does not have the clear on read behaviour of ICR).
     *
     * The VxWorks PRO/1000 driver uses this behaviour.
     */
    core->mac[ICS] = core->mac[ICR];

    interrupts_pending = (core->mac[IMS] & core->mac[ICR]) ? true : false;
    if (!interrupts_pending) {
        core->msi_causes_pending = 0;
    }

    trace_e1000e_irq_pending_interrupts(core->mac[ICR] & core->mac[IMS],
                                        core->mac[ICR], core->mac[IMS]);

    if (is_msix || msi_enabled(core->owner)) {
        if (interrupts_pending) {
            e1000e_send_msi(core, is_msix);
        }
    } else {
        if (interrupts_pending) {
            if (!e1000e_itr_should_postpone(core)) {
                e1000e_raise_legacy_irq(core);
            }
        } else {
            e1000e_lower_legacy_irq(core);
        }
    }
}

static void
e1000e_set_interrupt_cause(E1000ECore *core, uint32_t val)
{
    trace_e1000e_irq_set_cause_entry(val, core->mac[ICR]);

    val |= e1000e_intmgr_collect_delayed_causes(core);
    core->mac[ICR] |= val;

    trace_e1000e_irq_set_cause_exit(val, core->mac[ICR]);

    e1000e_update_interrupt_state(core);
}

static inline void
e1000e_autoneg_timer(void *opaque)
{
    E1000ECore *core = opaque;
    if (!qemu_get_queue(core->owner_nic)->link_down) {
        e1000x_update_regs_on_autoneg_done(core->mac, core->phy[0]);
        e1000e_start_recv(core);

        e1000e_update_flowctl_status(core);
        /* signal link status change to the guest */
        e1000e_set_interrupt_cause(core, E1000_ICR_LSC);
    }
}

static inline uint16_t
e1000e_get_reg_index_with_offset(const uint16_t *mac_reg_access, hwaddr addr)
{
    uint16_t index = (addr & 0x1ffff) >> 2;
    return index + (mac_reg_access[index] & 0xfffe);
}

static const char e1000e_phy_regcap[E1000E_PHY_PAGES][0x20] = {
    [0] = {
        [PHY_CTRL]          = PHY_ANYPAGE | PHY_RW,
        [PHY_STATUS]        = PHY_ANYPAGE | PHY_R,
        [PHY_ID1]           = PHY_ANYPAGE | PHY_R,
        [PHY_ID2]           = PHY_ANYPAGE | PHY_R,
        [PHY_AUTONEG_ADV]   = PHY_ANYPAGE | PHY_RW,
        [PHY_LP_ABILITY]    = PHY_ANYPAGE | PHY_R,
        [PHY_AUTONEG_EXP]   = PHY_ANYPAGE | PHY_R,
        [PHY_NEXT_PAGE_TX]  = PHY_ANYPAGE | PHY_RW,
        [PHY_LP_NEXT_PAGE]  = PHY_ANYPAGE | PHY_R,
        [PHY_1000T_CTRL]    = PHY_ANYPAGE | PHY_RW,
        [PHY_1000T_STATUS]  = PHY_ANYPAGE | PHY_R,
        [PHY_EXT_STATUS]    = PHY_ANYPAGE | PHY_R,
        [PHY_PAGE]          = PHY_ANYPAGE | PHY_RW,

        [PHY_COPPER_CTRL1]      = PHY_RW,
        [PHY_COPPER_STAT1]      = PHY_R,
        [PHY_COPPER_CTRL3]      = PHY_RW,
        [PHY_RX_ERR_CNTR]       = PHY_R,
        [PHY_OEM_BITS]          = PHY_RW,
        [PHY_BIAS_1]            = PHY_RW,
        [PHY_BIAS_2]            = PHY_RW,
        [PHY_COPPER_INT_ENABLE] = PHY_RW,
        [PHY_COPPER_STAT2]      = PHY_R,
        [PHY_COPPER_CTRL2]      = PHY_RW
    },
    [2] = {
        [PHY_MAC_CTRL1]         = PHY_RW,
        [PHY_MAC_INT_ENABLE]    = PHY_RW,
        [PHY_MAC_STAT]          = PHY_R,
        [PHY_MAC_CTRL2]         = PHY_RW
    },
    [3] = {
        [PHY_LED_03_FUNC_CTRL1] = PHY_RW,
        [PHY_LED_03_POL_CTRL]   = PHY_RW,
        [PHY_LED_TIMER_CTRL]    = PHY_RW,
        [PHY_LED_45_CTRL]       = PHY_RW
    },
    [5] = {
        [PHY_1000T_SKEW]        = PHY_R,
        [PHY_1000T_SWAP]        = PHY_R
    },
    [6] = {
        [PHY_CRC_COUNTERS]      = PHY_R
    }
};

static bool
e1000e_phy_reg_check_cap(E1000ECore *core, uint32_t addr,
                         char cap, uint8_t *page)
{
    *page =
        (e1000e_phy_regcap[0][addr] & PHY_ANYPAGE) ? 0
                                                    : core->phy[0][PHY_PAGE];

    if (*page >= E1000E_PHY_PAGES) {
        return false;
    }

    return e1000e_phy_regcap[*page][addr] & cap;
}

static void
e1000e_phy_reg_write(E1000ECore *core, uint8_t page,
                     uint32_t addr, uint16_t data)
{
    assert(page < E1000E_PHY_PAGES);
    assert(addr < E1000E_PHY_PAGE_SIZE);

    if (e1000e_phyreg_writeops[page][addr]) {
        e1000e_phyreg_writeops[page][addr](core, addr, data);
    } else {
        core->phy[page][addr] = data;
    }
}

static void
e1000e_set_mdic(E1000ECore *core, int index, uint32_t val)
{
    uint32_t data = val & E1000_MDIC_DATA_MASK;
    uint32_t addr = ((val & E1000_MDIC_REG_MASK) >> E1000_MDIC_REG_SHIFT);
    uint8_t page;

    if ((val & E1000_MDIC_PHY_MASK) >> E1000_MDIC_PHY_SHIFT != 1) { /* phy # */
        val = core->mac[MDIC] | E1000_MDIC_ERROR;
    } else if (val & E1000_MDIC_OP_READ) {
        if (!e1000e_phy_reg_check_cap(core, addr, PHY_R, &page)) {
            trace_e1000e_core_mdic_read_unhandled(page, addr);
            val |= E1000_MDIC_ERROR;
        } else {
            val = (val ^ data) | core->phy[page][addr];
            trace_e1000e_core_mdic_read(page, addr, val);
        }
    } else if (val & E1000_MDIC_OP_WRITE) {
        if (!e1000e_phy_reg_check_cap(core, addr, PHY_W, &page)) {
            trace_e1000e_core_mdic_write_unhandled(page, addr);
            val |= E1000_MDIC_ERROR;
        } else {
            trace_e1000e_core_mdic_write(page, addr, data);
            e1000e_phy_reg_write(core, page, addr, data);
        }
    }
    core->mac[MDIC] = val | E1000_MDIC_READY;

    if (val & E1000_MDIC_INT_EN) {
        e1000e_set_interrupt_cause(core, E1000_ICR_MDAC);
    }
}

static void
e1000e_set_rdt(E1000ECore *core, int index, uint32_t val)
{
    core->mac[index] = val & 0xffff;
    trace_e1000e_rx_set_rdt(e1000e_mq_queue_idx(RDT0, index), val);
    e1000e_start_recv(core);
}

static void
e1000e_set_status(E1000ECore *core, int index, uint32_t val)
{
    if ((val & E1000_STATUS_PHYRA) == 0) {
        core->mac[index] &= ~E1000_STATUS_PHYRA;
    }
}

static void
e1000e_set_ctrlext(E1000ECore *core, int index, uint32_t val)
{
    trace_e1000e_link_set_ext_params(!!(val & E1000_CTRL_EXT_ASDCHK),
                                     !!(val & E1000_CTRL_EXT_SPD_BYPS));

    /* Zero self-clearing bits */
    val &= ~(E1000_CTRL_EXT_ASDCHK | E1000_CTRL_EXT_EE_RST);
    core->mac[CTRL_EXT] = val;
}

static void
e1000e_set_pbaclr(E1000ECore *core, int index, uint32_t val)
{
    int i;

    core->mac[PBACLR] = val & E1000_PBACLR_VALID_MASK;

    if (!msix_enabled(core->owner)) {
        return;
    }

    for (i = 0; i < E1000E_MSIX_VEC_NUM; i++) {
        if (core->mac[PBACLR] & BIT(i)) {
            msix_clr_pending(core->owner, i);
        }
    }
}

static void
e1000e_set_fcrth(E1000ECore *core, int index, uint32_t val)
{
    core->mac[FCRTH] = val & 0xFFF8;
}

static void
e1000e_set_fcrtl(E1000ECore *core, int index, uint32_t val)
{
    core->mac[FCRTL] = val & 0x8000FFF8;
}

static inline void
e1000e_set_16bit(E1000ECore *core, int index, uint32_t val)
{
    core->mac[index] = val & 0xffff;
}

static void
e1000e_set_12bit(E1000ECore *core, int index, uint32_t val)
{
    core->mac[index] = val & 0xfff;
}

static void
e1000e_set_vet(E1000ECore *core, int index, uint32_t val)
{
    core->mac[VET] = val & 0xffff;
    trace_e1000e_vlan_vet(core->mac[VET]);
}

static void
e1000e_set_dlen(E1000ECore *core, int index, uint32_t val)
{
    core->mac[index] = val & E1000_XDLEN_MASK;
}

static void
e1000e_set_dbal(E1000ECore *core, int index, uint32_t val)
{
    core->mac[index] = val & E1000_XDBAL_MASK;
}

static void
e1000e_set_tctl(E1000ECore *core, int index, uint32_t val)
{
    E1000E_TxRing txr;
    core->mac[index] = val;

    if (core->mac[TARC0] & E1000_TARC_ENABLE) {
        e1000e_tx_ring_init(core, &txr, 0);
        e1000e_start_xmit(core, &txr);
    }

    if (core->mac[TARC1] & E1000_TARC_ENABLE) {
        e1000e_tx_ring_init(core, &txr, 1);
        e1000e_start_xmit(core, &txr);
    }
}

static void
e1000e_set_tdt(E1000ECore *core, int index, uint32_t val)
{
    E1000E_TxRing txr;
    int qidx = e1000e_mq_queue_idx(TDT, index);
    uint32_t tarc_reg = (qidx == 0) ? TARC0 : TARC1;

    core->mac[index] = val & 0xffff;

    if (core->mac[tarc_reg] & E1000_TARC_ENABLE) {
        e1000e_tx_ring_init(core, &txr, qidx);
        e1000e_start_xmit(core, &txr);
    }
}

static void
e1000e_set_ics(E1000ECore *core, int index, uint32_t val)
{
    trace_e1000e_irq_write_ics(val);
    e1000e_set_interrupt_cause(core, val);
}

static void
e1000e_set_icr(E1000ECore *core, int index, uint32_t val)
{
    uint32_t icr = 0;
    if ((core->mac[ICR] & E1000_ICR_ASSERTED) &&
        (core->mac[CTRL_EXT] & E1000_CTRL_EXT_IAME)) {
        trace_e1000e_irq_icr_process_iame();
        e1000e_clear_ims_bits(core, core->mac[IAM]);
    }

    icr = core->mac[ICR] & ~val;
    /* Windows driver expects that the "receive overrun" bit and other
     * ones to be cleared when the "Other" bit (#24) is cleared.
     */
    icr = (val & E1000_ICR_OTHER) ? (icr & ~E1000_ICR_OTHER_CAUSES) : icr;
    trace_e1000e_irq_icr_write(val, core->mac[ICR], icr);
    core->mac[ICR] = icr;
    e1000e_update_interrupt_state(core);
}

static void
e1000e_set_imc(E1000ECore *core, int index, uint32_t val)
{
    trace_e1000e_irq_ims_clear_set_imc(val);
    e1000e_clear_ims_bits(core, val);
    e1000e_update_interrupt_state(core);
}

static void
e1000e_set_ims(E1000ECore *core, int index, uint32_t val)
{
    static const uint32_t ims_ext_mask =
        E1000_IMS_RXQ0 | E1000_IMS_RXQ1 |
        E1000_IMS_TXQ0 | E1000_IMS_TXQ1 |
        E1000_IMS_OTHER;

    static const uint32_t ims_valid_mask =
        E1000_IMS_TXDW      | E1000_IMS_TXQE    | E1000_IMS_LSC  |
        E1000_IMS_RXDMT0    | E1000_IMS_RXO     | E1000_IMS_RXT0 |
        E1000_IMS_MDAC      | E1000_IMS_TXD_LOW | E1000_IMS_SRPD |
        E1000_IMS_ACK       | E1000_IMS_MNG     | E1000_IMS_RXQ0 |
        E1000_IMS_RXQ1      | E1000_IMS_TXQ0    | E1000_IMS_TXQ1 |
        E1000_IMS_OTHER;

    uint32_t valid_val = val & ims_valid_mask;

    trace_e1000e_irq_set_ims(val, core->mac[IMS], core->mac[IMS] | valid_val);
    core->mac[IMS] |= valid_val;

    if ((valid_val & ims_ext_mask) &&
        (core->mac[CTRL_EXT] & E1000_CTRL_EXT_PBA_CLR) &&
        msix_enabled(core->owner)) {
        e1000e_msix_clear(core, valid_val);
    }

    if ((valid_val == ims_valid_mask) &&
        (core->mac[CTRL_EXT] & E1000_CTRL_EXT_INT_TIMERS_CLEAR_ENA)) {
        trace_e1000e_irq_fire_all_timers(val);
        e1000e_intrmgr_fire_all_timers(core);
    }

    e1000e_update_interrupt_state(core);
}

static void
e1000e_set_rdtr(E1000ECore *core, int index, uint32_t val)
{
    e1000e_set_16bit(core, index, val);

    if ((val & E1000_RDTR_FPD) && (core->rdtr.running)) {
        trace_e1000e_irq_rdtr_fpd_running();
        e1000e_intrmgr_fire_delayed_interrupts(core);
    } else {
        trace_e1000e_irq_rdtr_fpd_not_running();
    }
}

static void
e1000e_set_tidv(E1000ECore *core, int index, uint32_t val)
{
    e1000e_set_16bit(core, index, val);

    if ((val & E1000_TIDV_FPD) && (core->tidv.running)) {
        trace_e1000e_irq_tidv_fpd_running();
        e1000e_intrmgr_fire_delayed_interrupts(core);
    } else {
        trace_e1000e_irq_tidv_fpd_not_running();
    }
}

static uint32_t
e1000e_mac_readreg(E1000ECore *core, int index)
{
    return core->mac[index];
}

static uint32_t
e1000e_mac_ics_read(E1000ECore *core, int index)
{
    trace_e1000e_irq_read_ics(core->mac[ICS]);
    return core->mac[ICS];
}

static uint32_t
e1000e_mac_ims_read(E1000ECore *core, int index)
{
    trace_e1000e_irq_read_ims(core->mac[IMS]);
    return core->mac[IMS];
}

#define E1000E_LOW_BITS_READ_FUNC(num)                      \
    static uint32_t                                         \
    e1000e_mac_low##num##_read(E1000ECore *core, int index) \
    {                                                       \
        return core->mac[index] & (BIT(num) - 1);           \
    }                                                       \

#define E1000E_LOW_BITS_READ(num)                           \
    e1000e_mac_low##num##_read

E1000E_LOW_BITS_READ_FUNC(4);
E1000E_LOW_BITS_READ_FUNC(6);
E1000E_LOW_BITS_READ_FUNC(11);
E1000E_LOW_BITS_READ_FUNC(13);
E1000E_LOW_BITS_READ_FUNC(16);

static uint32_t
e1000e_mac_swsm_read(E1000ECore *core, int index)
{
    uint32_t val = core->mac[SWSM];
    core->mac[SWSM] = val | 1;
    return val;
}

static uint32_t
e1000e_mac_itr_read(E1000ECore *core, int index)
{
    return core->itr_guest_value;
}

static uint32_t
e1000e_mac_eitr_read(E1000ECore *core, int index)
{
    return core->eitr_guest_value[index - EITR];
}

static uint32_t
e1000e_mac_icr_read(E1000ECore *core, int index)
{
    uint32_t ret = core->mac[ICR];
    trace_e1000e_irq_icr_read_entry(ret);

    if (core->mac[IMS] == 0) {
        trace_e1000e_irq_icr_clear_zero_ims();
        core->mac[ICR] = 0;
    }

    if (!msix_enabled(core->owner)) {
        trace_e1000e_irq_icr_clear_nonmsix_icr_read();
        core->mac[ICR] = 0;
    }

    if ((core->mac[ICR] & E1000_ICR_ASSERTED) &&
        (core->mac[CTRL_EXT] & E1000_CTRL_EXT_IAME)) {
        trace_e1000e_irq_icr_clear_iame();
        core->mac[ICR] = 0;
        trace_e1000e_irq_icr_process_iame();
        e1000e_clear_ims_bits(core, core->mac[IAM]);
    }

    trace_e1000e_irq_icr_read_exit(core->mac[ICR]);
    e1000e_update_interrupt_state(core);
    return ret;
}

static uint32_t
e1000e_mac_read_clr4(E1000ECore *core, int index)
{
    uint32_t ret = core->mac[index];

    core->mac[index] = 0;
    return ret;
}

static uint32_t
e1000e_mac_read_clr8(E1000ECore *core, int index)
{
    uint32_t ret = core->mac[index];

    core->mac[index] = 0;
    core->mac[index - 1] = 0;
    return ret;
}

static uint32_t
e1000e_get_ctrl(E1000ECore *core, int index)
{
    uint32_t val = core->mac[CTRL];

    trace_e1000e_link_read_params(
        !!(val & E1000_CTRL_ASDE),
        (val & E1000_CTRL_SPD_SEL) >> E1000_CTRL_SPD_SHIFT,
        !!(val & E1000_CTRL_FRCSPD),
        !!(val & E1000_CTRL_FRCDPX),
        !!(val & E1000_CTRL_RFCE),
        !!(val & E1000_CTRL_TFCE));

    return val;
}

static uint32_t
e1000e_get_status(E1000ECore *core, int index)
{
    uint32_t res = core->mac[STATUS];

    if (!(core->mac[CTRL] & E1000_CTRL_GIO_MASTER_DISABLE)) {
        res |= E1000_STATUS_GIO_MASTER_ENABLE;
    }

    if (core->mac[CTRL] & E1000_CTRL_FRCDPX) {
        res |= (core->mac[CTRL] & E1000_CTRL_FD) ? E1000_STATUS_FD : 0;
    } else {
        res |= E1000_STATUS_FD;
    }

    if ((core->mac[CTRL] & E1000_CTRL_FRCSPD) ||
        (core->mac[CTRL_EXT] & E1000_CTRL_EXT_SPD_BYPS)) {
        switch (core->mac[CTRL] & E1000_CTRL_SPD_SEL) {
        case E1000_CTRL_SPD_10:
            res |= E1000_STATUS_SPEED_10;
            break;
        case E1000_CTRL_SPD_100:
            res |= E1000_STATUS_SPEED_100;
            break;
        case E1000_CTRL_SPD_1000:
        default:
            res |= E1000_STATUS_SPEED_1000;
            break;
        }
    } else {
        res |= E1000_STATUS_SPEED_1000;
    }

    trace_e1000e_link_status(
        !!(res & E1000_STATUS_LU),
        !!(res & E1000_STATUS_FD),
        (res & E1000_STATUS_SPEED_MASK) >> E1000_STATUS_SPEED_SHIFT,
        (res & E1000_STATUS_ASDV) >> E1000_STATUS_ASDV_SHIFT);

    return res;
}

static uint32_t
e1000e_get_tarc(E1000ECore *core, int index)
{
    return core->mac[index] & ((BIT(11) - 1) |
                                BIT(27)      |
                                BIT(28)      |
                                BIT(29)      |
                                BIT(30));
}

static void
e1000e_mac_writereg(E1000ECore *core, int index, uint32_t val)
{
    core->mac[index] = val;
}

static void
e1000e_mac_setmacaddr(E1000ECore *core, int index, uint32_t val)
{
    uint32_t macaddr[2];

    core->mac[index] = val;

    macaddr[0] = cpu_to_le32(core->mac[RA]);
    macaddr[1] = cpu_to_le32(core->mac[RA + 1]);
    qemu_format_nic_info_str(qemu_get_queue(core->owner_nic),
        (uint8_t *) macaddr);

    trace_e1000e_mac_set_sw(MAC_ARG(macaddr));
}

static void
e1000e_set_eecd(E1000ECore *core, int index, uint32_t val)
{
    static const uint32_t ro_bits = E1000_EECD_PRES          |
                                    E1000_EECD_AUTO_RD       |
                                    E1000_EECD_SIZE_EX_MASK;

    core->mac[EECD] = (core->mac[EECD] & ro_bits) | (val & ~ro_bits);
}

static void
e1000e_set_eerd(E1000ECore *core, int index, uint32_t val)
{
    uint32_t addr = (val >> E1000_EERW_ADDR_SHIFT) & E1000_EERW_ADDR_MASK;
    uint32_t flags = 0;
    uint32_t data = 0;

    if ((addr < E1000E_EEPROM_SIZE) && (val & E1000_EERW_START)) {
        data = core->eeprom[addr];
        flags = E1000_EERW_DONE;
    }

    core->mac[EERD] = flags                           |
                      (addr << E1000_EERW_ADDR_SHIFT) |
                      (data << E1000_EERW_DATA_SHIFT);
}

static void
e1000e_set_eewr(E1000ECore *core, int index, uint32_t val)
{
    uint32_t addr = (val >> E1000_EERW_ADDR_SHIFT) & E1000_EERW_ADDR_MASK;
    uint32_t data = (val >> E1000_EERW_DATA_SHIFT) & E1000_EERW_DATA_MASK;
    uint32_t flags = 0;

    if ((addr < E1000E_EEPROM_SIZE) && (val & E1000_EERW_START)) {
        core->eeprom[addr] = data;
        flags = E1000_EERW_DONE;
    }

    core->mac[EERD] = flags                           |
                      (addr << E1000_EERW_ADDR_SHIFT) |
                      (data << E1000_EERW_DATA_SHIFT);
}

static void
e1000e_set_rxdctl(E1000ECore *core, int index, uint32_t val)
{
    core->mac[RXDCTL] = core->mac[RXDCTL1] = val;
}

static void
e1000e_set_itr(E1000ECore *core, int index, uint32_t val)
{
    uint32_t interval = val & 0xffff;

    trace_e1000e_irq_itr_set(val);

    core->itr_guest_value = interval;
    core->mac[index] = MAX(interval, E1000E_MIN_XITR);
}

static void
e1000e_set_eitr(E1000ECore *core, int index, uint32_t val)
{
    uint32_t interval = val & 0xffff;
    uint32_t eitr_num = index - EITR;

    trace_e1000e_irq_eitr_set(eitr_num, val);

    core->eitr_guest_value[eitr_num] = interval;
    core->mac[index] = MAX(interval, E1000E_MIN_XITR);
}

static void
e1000e_set_psrctl(E1000ECore *core, int index, uint32_t val)
{
    if (core->mac[RCTL] & E1000_RCTL_DTYP_MASK) {

        if ((val & E1000_PSRCTL_BSIZE0_MASK) == 0) {
            qemu_log_mask(LOG_GUEST_ERROR,
                          "e1000e: PSRCTL.BSIZE0 cannot be zero");
            return;
        }

        if ((val & E1000_PSRCTL_BSIZE1_MASK) == 0) {
            qemu_log_mask(LOG_GUEST_ERROR,
                          "e1000e: PSRCTL.BSIZE1 cannot be zero");
            return;
        }
    }

    core->mac[PSRCTL] = val;
}

static void
e1000e_update_rx_offloads(E1000ECore *core)
{
    int cso_state = e1000e_rx_l4_cso_enabled(core);

    trace_e1000e_rx_set_cso(cso_state);

    if (core->has_vnet) {
        qemu_set_offload(qemu_get_queue(core->owner_nic)->peer,
                         cso_state, 0, 0, 0, 0);
    }
}

static void
e1000e_set_rxcsum(E1000ECore *core, int index, uint32_t val)
{
    core->mac[RXCSUM] = val;
    e1000e_update_rx_offloads(core);
}

static void
e1000e_set_gcr(E1000ECore *core, int index, uint32_t val)
{
    uint32_t ro_bits = core->mac[GCR] & E1000_GCR_RO_BITS;
    core->mac[GCR] = (val & ~E1000_GCR_RO_BITS) | ro_bits;
}

#define e1000e_getreg(x)    [x] = e1000e_mac_readreg
typedef uint32_t (*readops)(E1000ECore *, int);
static const readops e1000e_macreg_readops[] = {
    e1000e_getreg(PBA),
    e1000e_getreg(WUFC),
    e1000e_getreg(MANC),
    e1000e_getreg(TOTL),
    e1000e_getreg(RDT0),
    e1000e_getreg(RDBAH0),
    e1000e_getreg(TDBAL1),
    e1000e_getreg(RDLEN0),
    e1000e_getreg(RDH1),
    e1000e_getreg(LATECOL),
    e1000e_getreg(SEQEC),
    e1000e_getreg(XONTXC),
    e1000e_getreg(WUS),
    e1000e_getreg(GORCL),
    e1000e_getreg(MGTPRC),
    e1000e_getreg(EERD),
    e1000e_getreg(EIAC),
    e1000e_getreg(PSRCTL),
    e1000e_getreg(MANC2H),
    e1000e_getreg(RXCSUM),
    e1000e_getreg(GSCL_3),
    e1000e_getreg(GSCN_2),
    e1000e_getreg(RSRPD),
    e1000e_getreg(RDBAL1),
    e1000e_getreg(FCAH),
    e1000e_getreg(FCRTH),
    e1000e_getreg(FLOP),
    e1000e_getreg(FLASHT),
    e1000e_getreg(RXSTMPH),
    e1000e_getreg(TXSTMPL),
    e1000e_getreg(TIMADJL),
    e1000e_getreg(TXDCTL),
    e1000e_getreg(RDH0),
    e1000e_getreg(TDT1),
    e1000e_getreg(TNCRS),
    e1000e_getreg(RJC),
    e1000e_getreg(IAM),
    e1000e_getreg(GSCL_2),
    e1000e_getreg(RDBAH1),
    e1000e_getreg(FLSWDATA),
    e1000e_getreg(RXSATRH),
    e1000e_getreg(TIPG),
    e1000e_getreg(FLMNGCTL),
    e1000e_getreg(FLMNGCNT),
    e1000e_getreg(TSYNCTXCTL),
    e1000e_getreg(EXTCNF_SIZE),
    e1000e_getreg(EXTCNF_CTRL),
    e1000e_getreg(EEMNGDATA),
    e1000e_getreg(CTRL_EXT),
    e1000e_getreg(SYSTIMH),
    e1000e_getreg(EEMNGCTL),
    e1000e_getreg(FLMNGDATA),
    e1000e_getreg(TSYNCRXCTL),
    e1000e_getreg(TDH),
    e1000e_getreg(LEDCTL),
    e1000e_getreg(TCTL),
    e1000e_getreg(TDBAL),
    e1000e_getreg(TDLEN),
    e1000e_getreg(TDH1),
    e1000e_getreg(RADV),
    e1000e_getreg(ECOL),
    e1000e_getreg(DC),
    e1000e_getreg(RLEC),
    e1000e_getreg(XOFFTXC),
    e1000e_getreg(RFC),
    e1000e_getreg(RNBC),
    e1000e_getreg(MGTPTC),
    e1000e_getreg(TIMINCA),
    e1000e_getreg(RXCFGL),
    e1000e_getreg(MFUTP01),
    e1000e_getreg(FACTPS),
    e1000e_getreg(GSCL_1),
    e1000e_getreg(GSCN_0),
    e1000e_getreg(GCR2),
    e1000e_getreg(RDT1),
    e1000e_getreg(PBACLR),
    e1000e_getreg(FCTTV),
    e1000e_getreg(EEWR),
    e1000e_getreg(FLSWCTL),
    e1000e_getreg(RXDCTL1),
    e1000e_getreg(RXSATRL),
    e1000e_getreg(SYSTIML),
    e1000e_getreg(RXUDP),
    e1000e_getreg(TORL),
    e1000e_getreg(TDLEN1),
    e1000e_getreg(MCC),
    e1000e_getreg(WUC),
    e1000e_getreg(EECD),
    e1000e_getreg(MFUTP23),
    e1000e_getreg(RAID),
    e1000e_getreg(FCRTV),
    e1000e_getreg(TXDCTL1),
    e1000e_getreg(RCTL),
    e1000e_getreg(TDT),
    e1000e_getreg(MDIC),
    e1000e_getreg(FCRUC),
    e1000e_getreg(VET),
    e1000e_getreg(RDBAL0),
    e1000e_getreg(TDBAH1),
    e1000e_getreg(RDTR),
    e1000e_getreg(SCC),
    e1000e_getreg(COLC),
    e1000e_getreg(CEXTERR),
    e1000e_getreg(XOFFRXC),
    e1000e_getreg(IPAV),
    e1000e_getreg(GOTCL),
    e1000e_getreg(MGTPDC),
    e1000e_getreg(GCR),
    e1000e_getreg(IVAR),
    e1000e_getreg(POEMB),
    e1000e_getreg(MFVAL),
    e1000e_getreg(FUNCTAG),
    e1000e_getreg(GSCL_4),
    e1000e_getreg(GSCN_3),
    e1000e_getreg(MRQC),
    e1000e_getreg(RDLEN1),
    e1000e_getreg(FCT),
    e1000e_getreg(FLA),
    e1000e_getreg(FLOL),
    e1000e_getreg(RXDCTL),
    e1000e_getreg(RXSTMPL),
    e1000e_getreg(TXSTMPH),
    e1000e_getreg(TIMADJH),
    e1000e_getreg(FCRTL),
    e1000e_getreg(TDBAH),
    e1000e_getreg(TADV),
    e1000e_getreg(XONRXC),
    e1000e_getreg(TSCTFC),
    e1000e_getreg(RFCTL),
    e1000e_getreg(GSCN_1),
    e1000e_getreg(FCAL),
    e1000e_getreg(FLSWCNT),

    [TOTH]    = e1000e_mac_read_clr8,
    [GOTCH]   = e1000e_mac_read_clr8,
    [PRC64]   = e1000e_mac_read_clr4,
    [PRC255]  = e1000e_mac_read_clr4,
    [PRC1023] = e1000e_mac_read_clr4,
    [PTC64]   = e1000e_mac_read_clr4,