Adding upstream version 1:7.2+dfsg.upstream/1%7.2+dfsgupstream

Signed-off-by: Daniel Baumann <mail@daniel-baumann.ch>

1 files changed, 3907 insertions, 0 deletions

diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
new file mode 100644
index 00000000..aba12759
--- /dev/null
+++ b/hw/net/virtio-net.c
@@ -0,0 +1,3907 @@
+/*
+ * Virtio Network Device
+ *
+ * Copyright IBM, Corp. 2007
+ *
+ * Authors:
+ *  Anthony Liguori   <aliguori@us.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the COPYING file in the top-level directory.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/atomic.h"
+#include "qemu/iov.h"
+#include "qemu/log.h"
+#include "qemu/main-loop.h"
+#include "qemu/module.h"
+#include "hw/virtio/virtio.h"
+#include "net/net.h"
+#include "net/checksum.h"
+#include "net/tap.h"
+#include "qemu/error-report.h"
+#include "qemu/timer.h"
+#include "qemu/option.h"
+#include "qemu/option_int.h"
+#include "qemu/config-file.h"
+#include "qapi/qmp/qdict.h"
+#include "hw/virtio/virtio-net.h"
+#include "net/vhost_net.h"
+#include "net/announce.h"
+#include "hw/virtio/virtio-bus.h"
+#include "qapi/error.h"
+#include "qapi/qapi-events-net.h"
+#include "hw/qdev-properties.h"
+#include "qapi/qapi-types-migration.h"
+#include "qapi/qapi-events-migration.h"
+#include "hw/virtio/virtio-access.h"
+#include "migration/misc.h"
+#include "standard-headers/linux/ethtool.h"
+#include "sysemu/sysemu.h"
+#include "trace.h"
+#include "monitor/qdev.h"
+#include "hw/pci/pci.h"
+#include "net_rx_pkt.h"
+#include "hw/virtio/vhost.h"
+#include "sysemu/qtest.h"
+
+#define VIRTIO_NET_VM_VERSION    11
+
+#define MAX_VLAN    (1 << 12)   /* Per 802.1Q definition */
+
+/* previously fixed value */
+#define VIRTIO_NET_RX_QUEUE_DEFAULT_SIZE 256
+#define VIRTIO_NET_TX_QUEUE_DEFAULT_SIZE 256
+
+/* for now, only allow larger queue_pairs; with virtio-1, guest can downsize */
+#define VIRTIO_NET_RX_QUEUE_MIN_SIZE VIRTIO_NET_RX_QUEUE_DEFAULT_SIZE
+#define VIRTIO_NET_TX_QUEUE_MIN_SIZE VIRTIO_NET_TX_QUEUE_DEFAULT_SIZE
+
+#define VIRTIO_NET_IP4_ADDR_SIZE   8        /* ipv4 saddr + daddr */
+
+#define VIRTIO_NET_TCP_FLAG         0x3F
+#define VIRTIO_NET_TCP_HDR_LENGTH   0xF000
+
+/* IPv4 max payload, 16 bits in the header */
+#define VIRTIO_NET_MAX_IP4_PAYLOAD (65535 - sizeof(struct ip_header))
+#define VIRTIO_NET_MAX_TCP_PAYLOAD 65535
+
+/* header length value in ip header without option */
+#define VIRTIO_NET_IP4_HEADER_LENGTH 5
+
+#define VIRTIO_NET_IP6_ADDR_SIZE   32      /* ipv6 saddr + daddr */
+#define VIRTIO_NET_MAX_IP6_PAYLOAD VIRTIO_NET_MAX_TCP_PAYLOAD
+
+/* Purge coalesced packets timer interval, This value affects the performance
+   a lot, and should be tuned carefully, '300000'(300us) is the recommended
+   value to pass the WHQL test, '50000' can gain 2x netperf throughput with
+   tso/gso/gro 'off'. */
+#define VIRTIO_NET_RSC_DEFAULT_INTERVAL 300000
+
+#define VIRTIO_NET_RSS_SUPPORTED_HASHES (VIRTIO_NET_RSS_HASH_TYPE_IPv4 | \
+                                         VIRTIO_NET_RSS_HASH_TYPE_TCPv4 | \
+                                         VIRTIO_NET_RSS_HASH_TYPE_UDPv4 | \
+                                         VIRTIO_NET_RSS_HASH_TYPE_IPv6 | \
+                                         VIRTIO_NET_RSS_HASH_TYPE_TCPv6 | \
+                                         VIRTIO_NET_RSS_HASH_TYPE_UDPv6 | \
+                                         VIRTIO_NET_RSS_HASH_TYPE_IP_EX | \
+                                         VIRTIO_NET_RSS_HASH_TYPE_TCP_EX | \
+                                         VIRTIO_NET_RSS_HASH_TYPE_UDP_EX)
+
+static const VirtIOFeature feature_sizes[] = {
+    {.flags = 1ULL << VIRTIO_NET_F_MAC,
+     .end = endof(struct virtio_net_config, mac)},
+    {.flags = 1ULL << VIRTIO_NET_F_STATUS,
+     .end = endof(struct virtio_net_config, status)},
+    {.flags = 1ULL << VIRTIO_NET_F_MQ,
+     .end = endof(struct virtio_net_config, max_virtqueue_pairs)},
+    {.flags = 1ULL << VIRTIO_NET_F_MTU,
+     .end = endof(struct virtio_net_config, mtu)},
+    {.flags = 1ULL << VIRTIO_NET_F_SPEED_DUPLEX,
+     .end = endof(struct virtio_net_config, duplex)},
+    {.flags = (1ULL << VIRTIO_NET_F_RSS) | (1ULL << VIRTIO_NET_F_HASH_REPORT),
+     .end = endof(struct virtio_net_config, supported_hash_types)},
+    {}
+};
+
+static const VirtIOConfigSizeParams cfg_size_params = {
+    .min_size = endof(struct virtio_net_config, mac),
+    .max_size = sizeof(struct virtio_net_config),
+    .feature_sizes = feature_sizes
+};
+
+static VirtIONetQueue *virtio_net_get_subqueue(NetClientState *nc)
+{
+    VirtIONet *n = qemu_get_nic_opaque(nc);
+
+    return &n->vqs[nc->queue_index];
+}
+
+static int vq2q(int queue_index)
+{
+    return queue_index / 2;
+}
+
+static void flush_or_purge_queued_packets(NetClientState *nc)
+{
+    if (!nc->peer) {
+        return;
+    }
+
+    qemu_flush_or_purge_queued_packets(nc->peer, true);
+    assert(!virtio_net_get_subqueue(nc)->async_tx.elem);
+}
+
+/* TODO
+ * - we could suppress RX interrupt if we were so inclined.
+ */
+
+static void virtio_net_get_config(VirtIODevice *vdev, uint8_t *config)
+{
+    VirtIONet *n = VIRTIO_NET(vdev);
+    struct virtio_net_config netcfg;
+    NetClientState *nc = qemu_get_queue(n->nic);
+    static const MACAddr zero = { .a = { 0, 0, 0, 0, 0, 0 } };
+
+    int ret = 0;
+    memset(&netcfg, 0 , sizeof(struct virtio_net_config));
+    virtio_stw_p(vdev, &netcfg.status, n->status);
+    virtio_stw_p(vdev, &netcfg.max_virtqueue_pairs, n->max_queue_pairs);
+    virtio_stw_p(vdev, &netcfg.mtu, n->net_conf.mtu);
+    memcpy(netcfg.mac, n->mac, ETH_ALEN);
+    virtio_stl_p(vdev, &netcfg.speed, n->net_conf.speed);
+    netcfg.duplex = n->net_conf.duplex;
+    netcfg.rss_max_key_size = VIRTIO_NET_RSS_MAX_KEY_SIZE;
+    virtio_stw_p(vdev, &netcfg.rss_max_indirection_table_length,
+                 virtio_host_has_feature(vdev, VIRTIO_NET_F_RSS) ?
+                 VIRTIO_NET_RSS_MAX_TABLE_LEN : 1);
+    virtio_stl_p(vdev, &netcfg.supported_hash_types,
+                 VIRTIO_NET_RSS_SUPPORTED_HASHES);
+    memcpy(config, &netcfg, n->config_size);
+
+    /*
+     * Is this VDPA? No peer means not VDPA: there's no way to
+     * disconnect/reconnect a VDPA peer.
+     */
+    if (nc->peer && nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_VDPA) {
+        ret = vhost_net_get_config(get_vhost_net(nc->peer), (uint8_t *)&netcfg,
+                                   n->config_size);
+        if (ret != -1) {
+            /*
+             * Some NIC/kernel combinations present 0 as the mac address.  As
+             * that is not a legal address, try to proceed with the
+             * address from the QEMU command line in the hope that the
+             * address has been configured correctly elsewhere - just not
+             * reported by the device.
+             */
+            if (memcmp(&netcfg.mac, &zero, sizeof(zero)) == 0) {
+                info_report("Zero hardware mac address detected. Ignoring.");
+                memcpy(netcfg.mac, n->mac, ETH_ALEN);
+            }
+            memcpy(config, &netcfg, n->config_size);
+        }
+    }
+}
+
+static void virtio_net_set_config(VirtIODevice *vdev, const uint8_t *config)
+{
+    VirtIONet *n = VIRTIO_NET(vdev);
+    struct virtio_net_config netcfg = {};
+    NetClientState *nc = qemu_get_queue(n->nic);
+
+    memcpy(&netcfg, config, n->config_size);
+
+    if (!virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR) &&
+        !virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1) &&
+        memcmp(netcfg.mac, n->mac, ETH_ALEN)) {
+        memcpy(n->mac, netcfg.mac, ETH_ALEN);
+        qemu_format_nic_info_str(qemu_get_queue(n->nic), n->mac);
+    }
+
+    /*
+     * Is this VDPA? No peer means not VDPA: there's no way to
+     * disconnect/reconnect a VDPA peer.
+     */
+    if (nc->peer && nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_VDPA) {
+        vhost_net_set_config(get_vhost_net(nc->peer),
+                             (uint8_t *)&netcfg, 0, n->config_size,
+                             VHOST_SET_CONFIG_TYPE_MASTER);
+      }
+}
+
+static bool virtio_net_started(VirtIONet *n, uint8_t status)
+{
+    VirtIODevice *vdev = VIRTIO_DEVICE(n);
+    return (status & VIRTIO_CONFIG_S_DRIVER_OK) &&
+        (n->status & VIRTIO_NET_S_LINK_UP) && vdev->vm_running;
+}
+
+static void virtio_net_announce_notify(VirtIONet *net)
+{
+    VirtIODevice *vdev = VIRTIO_DEVICE(net);
+    trace_virtio_net_announce_notify();
+
+    net->status |= VIRTIO_NET_S_ANNOUNCE;
+    virtio_notify_config(vdev);
+}
+
+static void virtio_net_announce_timer(void *opaque)
+{
+    VirtIONet *n = opaque;
+    trace_virtio_net_announce_timer(n->announce_timer.round);
+
+    n->announce_timer.round--;
+    virtio_net_announce_notify(n);
+}
+
+static void virtio_net_announce(NetClientState *nc)
+{
+    VirtIONet *n = qemu_get_nic_opaque(nc);
+    VirtIODevice *vdev = VIRTIO_DEVICE(n);
+
+    /*
+     * Make sure the virtio migration announcement timer isn't running
+     * If it is, let it trigger announcement so that we do not cause
+     * confusion.
+     */
+    if (n->announce_timer.round) {
+        return;
+    }
+
+    if (virtio_vdev_has_feature(vdev, VIRTIO_NET_F_GUEST_ANNOUNCE) &&
+        virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ)) {
+            virtio_net_announce_notify(n);
+    }
+}
+
+static void virtio_net_vhost_status(VirtIONet *n, uint8_t status)
+{
+    VirtIODevice *vdev = VIRTIO_DEVICE(n);
+    NetClientState *nc = qemu_get_queue(n->nic);
+    int queue_pairs = n->multiqueue ? n->max_queue_pairs : 1;
+    int cvq = virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ) ?
+              n->max_ncs - n->max_queue_pairs : 0;
+
+    if (!get_vhost_net(nc->peer)) {
+        return;
+    }
+
+    if ((virtio_net_started(n, status) && !nc->peer->link_down) ==
+        !!n->vhost_started) {
+        return;
+    }
+    if (!n->vhost_started) {
+        int r, i;
+
+        if (n->needs_vnet_hdr_swap) {
+            error_report("backend does not support %s vnet headers; "
+                         "falling back on userspace virtio",
+                         virtio_is_big_endian(vdev) ? "BE" : "LE");
+            return;
+        }
+
+        /* Any packets outstanding? Purge them to avoid touching rings
+         * when vhost is running.
+         */
+        for (i = 0;  i < queue_pairs; i++) {
+            NetClientState *qnc = qemu_get_subqueue(n->nic, i);
+
+            /* Purge both directions: TX and RX. */
+            qemu_net_queue_purge(qnc->peer->incoming_queue, qnc);
+            qemu_net_queue_purge(qnc->incoming_queue, qnc->peer);
+        }
+
+        if (virtio_has_feature(vdev->guest_features, VIRTIO_NET_F_MTU)) {
+            r = vhost_net_set_mtu(get_vhost_net(nc->peer), n->net_conf.mtu);
+            if (r < 0) {
+                error_report("%uBytes MTU not supported by the backend",
+                             n->net_conf.mtu);
+
+                return;
+            }
+        }
+
+        n->vhost_started = 1;
+        r = vhost_net_start(vdev, n->nic->ncs, queue_pairs, cvq);
+        if (r < 0) {
+            error_report("unable to start vhost net: %d: "
+                         "falling back on userspace virtio", -r);
+            n->vhost_started = 0;
+        }
+    } else {
+        vhost_net_stop(vdev, n->nic->ncs, queue_pairs, cvq);
+        n->vhost_started = 0;
+    }
+}
+
+static int virtio_net_set_vnet_endian_one(VirtIODevice *vdev,
+                                          NetClientState *peer,
+                                          bool enable)
+{
+    if (virtio_is_big_endian(vdev)) {
+        return qemu_set_vnet_be(peer, enable);
+    } else {
+        return qemu_set_vnet_le(peer, enable);
+    }
+}
+
+static bool virtio_net_set_vnet_endian(VirtIODevice *vdev, NetClientState *ncs,
+                                       int queue_pairs, bool enable)
+{
+    int i;
+
+    for (i = 0; i < queue_pairs; i++) {
+        if (virtio_net_set_vnet_endian_one(vdev, ncs[i].peer, enable) < 0 &&
+            enable) {
+            while (--i >= 0) {
+                virtio_net_set_vnet_endian_one(vdev, ncs[i].peer, false);
+            }
+
+            return true;
+        }
+    }
+
+    return false;
+}
+
+static void virtio_net_vnet_endian_status(VirtIONet *n, uint8_t status)
+{
+    VirtIODevice *vdev = VIRTIO_DEVICE(n);
+    int queue_pairs = n->multiqueue ? n->max_queue_pairs : 1;
+
+    if (virtio_net_started(n, status)) {
+        /* Before using the device, we tell the network backend about the
+         * endianness to use when parsing vnet headers. If the backend
+         * can't do it, we fallback onto fixing the headers in the core
+         * virtio-net code.
+         */
+        n->needs_vnet_hdr_swap = virtio_net_set_vnet_endian(vdev, n->nic->ncs,
+                                                            queue_pairs, true);
+    } else if (virtio_net_started(n, vdev->status)) {
+        /* After using the device, we need to reset the network backend to
+         * the default (guest native endianness), otherwise the guest may
+         * lose network connectivity if it is rebooted into a different
+         * endianness.
+         */
+        virtio_net_set_vnet_endian(vdev, n->nic->ncs, queue_pairs, false);
+    }
+}
+
+static void virtio_net_drop_tx_queue_data(VirtIODevice *vdev, VirtQueue *vq)
+{
+    unsigned int dropped = virtqueue_drop_all(vq);
+    if (dropped) {
+        virtio_notify(vdev, vq);
+    }
+}
+
+static void virtio_net_set_status(struct VirtIODevice *vdev, uint8_t status)
+{
+    VirtIONet *n = VIRTIO_NET(vdev);
+    VirtIONetQueue *q;
+    int i;
+    uint8_t queue_status;
+
+    virtio_net_vnet_endian_status(n, status);
+    virtio_net_vhost_status(n, status);
+
+    for (i = 0; i < n->max_queue_pairs; i++) {
+        NetClientState *ncs = qemu_get_subqueue(n->nic, i);
+        bool queue_started;
+        q = &n->vqs[i];
+
+        if ((!n->multiqueue && i != 0) || i >= n->curr_queue_pairs) {
+            queue_status = 0;
+        } else {
+            queue_status = status;
+        }
+        queue_started =
+            virtio_net_started(n, queue_status) && !n->vhost_started;
+
+        if (queue_started) {
+            qemu_flush_queued_packets(ncs);
+        }
+
+        if (!q->tx_waiting) {
+            continue;
+        }
+
+        if (queue_started) {
+            if (q->tx_timer) {
+                timer_mod(q->tx_timer,
+                               qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + n->tx_timeout);
+            } else {
+                qemu_bh_schedule(q->tx_bh);
+            }
+        } else {
+            if (q->tx_timer) {
+                timer_del(q->tx_timer);
+            } else {
+                qemu_bh_cancel(q->tx_bh);
+            }
+            if ((n->status & VIRTIO_NET_S_LINK_UP) == 0 &&
+                (queue_status & VIRTIO_CONFIG_S_DRIVER_OK) &&
+                vdev->vm_running) {
+                /* if tx is waiting we are likely have some packets in tx queue
+                 * and disabled notification */
+                q->tx_waiting = 0;
+                virtio_queue_set_notification(q->tx_vq, 1);
+                virtio_net_drop_tx_queue_data(vdev, q->tx_vq);
+            }
+        }
+    }
+}
+
+static void virtio_net_set_link_status(NetClientState *nc)
+{
+    VirtIONet *n = qemu_get_nic_opaque(nc);
+    VirtIODevice *vdev = VIRTIO_DEVICE(n);
+    uint16_t old_status = n->status;
+
+    if (nc->link_down)
+        n->status &= ~VIRTIO_NET_S_LINK_UP;
+    else
+        n->status |= VIRTIO_NET_S_LINK_UP;
+
+    if (n->status != old_status)
+        virtio_notify_config(vdev);
+
+    virtio_net_set_status(vdev, vdev->status);
+}
+
+static void rxfilter_notify(NetClientState *nc)
+{
+    VirtIONet *n = qemu_get_nic_opaque(nc);
+
+    if (nc->rxfilter_notify_enabled) {
+        char *path = object_get_canonical_path(OBJECT(n->qdev));
+        qapi_event_send_nic_rx_filter_changed(!!n->netclient_name,
+                                              n->netclient_name, path);
+        g_free(path);
+
+        /* disable event notification to avoid events flooding */
+        nc->rxfilter_notify_enabled = 0;
+    }
+}
+
+static intList *get_vlan_table(VirtIONet *n)
+{
+    intList *list;
+    int i, j;
+
+    list = NULL;
+    for (i = 0; i < MAX_VLAN >> 5; i++) {
+        for (j = 0; n->vlans[i] && j <= 0x1f; j++) {
+            if (n->vlans[i] & (1U << j)) {
+                QAPI_LIST_PREPEND(list, (i << 5) + j);
+            }
+        }
+    }
+
+    return list;
+}
+
+static RxFilterInfo *virtio_net_query_rxfilter(NetClientState *nc)
+{
+    VirtIONet *n = qemu_get_nic_opaque(nc);
+    VirtIODevice *vdev = VIRTIO_DEVICE(n);
+    RxFilterInfo *info;
+    strList *str_list;
+    int i;
+
+    info = g_malloc0(sizeof(*info));
+    info->name = g_strdup(nc->name);
+    info->promiscuous = n->promisc;
+
+    if (n->nouni) {
+        info->unicast = RX_STATE_NONE;
+    } else if (n->alluni) {
+        info->unicast = RX_STATE_ALL;
+    } else {
+        info->unicast = RX_STATE_NORMAL;
+    }
+
+    if (n->nomulti) {
+        info->multicast = RX_STATE_NONE;
+    } else if (n->allmulti) {
+        info->multicast = RX_STATE_ALL;
+    } else {
+        info->multicast = RX_STATE_NORMAL;
+    }
+
+    info->broadcast_allowed = n->nobcast;
+    info->multicast_overflow = n->mac_table.multi_overflow;
+    info->unicast_overflow = n->mac_table.uni_overflow;
+
+    info->main_mac = qemu_mac_strdup_printf(n->mac);
+
+    str_list = NULL;
+    for (i = 0; i < n->mac_table.first_multi; i++) {
+        QAPI_LIST_PREPEND(str_list,
+                      qemu_mac_strdup_printf(n->mac_table.macs + i * ETH_ALEN));
+    }
+    info->unicast_table = str_list;
+
+    str_list = NULL;
+    for (i = n->mac_table.first_multi; i < n->mac_table.in_use; i++) {
+        QAPI_LIST_PREPEND(str_list,
+                      qemu_mac_strdup_printf(n->mac_table.macs + i * ETH_ALEN));
+    }
+    info->multicast_table = str_list;
+    info->vlan_table = get_vlan_table(n);
+
+    if (!virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_VLAN)) {
+        info->vlan = RX_STATE_ALL;
+    } else if (!info->vlan_table) {
+        info->vlan = RX_STATE_NONE;
+    } else {
+        info->vlan = RX_STATE_NORMAL;
+    }
+
+    /* enable event notification after query */
+    nc->rxfilter_notify_enabled = 1;
+
+    return info;
+}
+
+static void virtio_net_queue_reset(VirtIODevice *vdev, uint32_t queue_index)
+{
+    VirtIONet *n = VIRTIO_NET(vdev);
+    NetClientState *nc;
+
+    /* validate queue_index and skip for cvq */
+    if (queue_index >= n->max_queue_pairs * 2) {
+        return;
+    }
+
+    nc = qemu_get_subqueue(n->nic, vq2q(queue_index));
+
+    if (!nc->peer) {
+        return;
+    }
+
+    if (get_vhost_net(nc->peer) &&
+        nc->peer->info->type == NET_CLIENT_DRIVER_TAP) {
+        vhost_net_virtqueue_reset(vdev, nc, queue_index);
+    }
+
+    flush_or_purge_queued_packets(nc);
+}
+
+static void virtio_net_queue_enable(VirtIODevice *vdev, uint32_t queue_index)
+{
+    VirtIONet *n = VIRTIO_NET(vdev);
+    NetClientState *nc;
+    int r;
+
+    /* validate queue_index and skip for cvq */
+    if (queue_index >= n->max_queue_pairs * 2) {
+        return;
+    }
+
+    nc = qemu_get_subqueue(n->nic, vq2q(queue_index));
+
+    if (!nc->peer || !vdev->vhost_started) {
+        return;
+    }
+
+    if (get_vhost_net(nc->peer) &&
+        nc->peer->info->type == NET_CLIENT_DRIVER_TAP) {
+        r = vhost_net_virtqueue_restart(vdev, nc, queue_index);
+        if (r < 0) {
+            error_report("unable to restart vhost net virtqueue: %d, "
+                            "when resetting the queue", queue_index);
+        }
+    }
+}
+
+static void virtio_net_reset(VirtIODevice *vdev)
+{
+    VirtIONet *n = VIRTIO_NET(vdev);
+    int i;
+
+    /* Reset back to compatibility mode */
+    n->promisc = 1;
+    n->allmulti = 0;
+    n->alluni = 0;
+    n->nomulti = 0;
+    n->nouni = 0;
+    n->nobcast = 0;
+    /* multiqueue is disabled by default */
+    n->curr_queue_pairs = 1;
+    timer_del(n->announce_timer.tm);
+    n->announce_timer.round = 0;
+    n->status &= ~VIRTIO_NET_S_ANNOUNCE;
+
+    /* Flush any MAC and VLAN filter table state */
+    n->mac_table.in_use = 0;
+    n->mac_table.first_multi = 0;
+    n->mac_table.multi_overflow = 0;
+    n->mac_table.uni_overflow = 0;
+    memset(n->mac_table.macs, 0, MAC_TABLE_ENTRIES * ETH_ALEN);
+    memcpy(&n->mac[0], &n->nic->conf->macaddr, sizeof(n->mac));
+    qemu_format_nic_info_str(qemu_get_queue(n->nic), n->mac);
+    memset(n->vlans, 0, MAX_VLAN >> 3);
+
+    /* Flush any async TX */
+    for (i = 0;  i < n->max_queue_pairs; i++) {
+        flush_or_purge_queued_packets(qemu_get_subqueue(n->nic, i));
+    }
+}
+
+static void peer_test_vnet_hdr(VirtIONet *n)
+{
+    NetClientState *nc = qemu_get_queue(n->nic);
+    if (!nc->peer) {
+        return;
+    }
+
+    n->has_vnet_hdr = qemu_has_vnet_hdr(nc->peer);
+}
+
+static int peer_has_vnet_hdr(VirtIONet *n)
+{
+    return n->has_vnet_hdr;
+}
+
+static int peer_has_ufo(VirtIONet *n)
+{
+    if (!peer_has_vnet_hdr(n))
+        return 0;
+
+    n->has_ufo = qemu_has_ufo(qemu_get_queue(n->nic)->peer);
+
+    return n->has_ufo;
+}
+
+static void virtio_net_set_mrg_rx_bufs(VirtIONet *n, int mergeable_rx_bufs,
+                                       int version_1, int hash_report)
+{
+    int i;
+    NetClientState *nc;
+
+    n->mergeable_rx_bufs = mergeable_rx_bufs;
+
+    if (version_1) {
+        n->guest_hdr_len = hash_report ?
+            sizeof(struct virtio_net_hdr_v1_hash) :
+            sizeof(struct virtio_net_hdr_mrg_rxbuf);
+        n->rss_data.populate_hash = !!hash_report;
+    } else {
+        n->guest_hdr_len = n->mergeable_rx_bufs ?
+            sizeof(struct virtio_net_hdr_mrg_rxbuf) :
+            sizeof(struct virtio_net_hdr);
+    }
+
+    for (i = 0; i < n->max_queue_pairs; i++) {
+        nc = qemu_get_subqueue(n->nic, i);
+
+        if (peer_has_vnet_hdr(n) &&
+            qemu_has_vnet_hdr_len(nc->peer, n->guest_hdr_len)) {
+            qemu_set_vnet_hdr_len(nc->peer, n->guest_hdr_len);
+            n->host_hdr_len = n->guest_hdr_len;
+        }
+    }
+}
+
+static int virtio_net_max_tx_queue_size(VirtIONet *n)
+{
+    NetClientState *peer = n->nic_conf.peers.ncs[0];
+
+    /*
+     * Backends other than vhost-user or vhost-vdpa don't support max queue
+     * size.
+     */
+    if (!peer) {
+        return VIRTIO_NET_TX_QUEUE_DEFAULT_SIZE;
+    }
+
+    switch(peer->info->type) {
+    case NET_CLIENT_DRIVER_VHOST_USER:
+    case NET_CLIENT_DRIVER_VHOST_VDPA:
+        return VIRTQUEUE_MAX_SIZE;
+    default:
+        return VIRTIO_NET_TX_QUEUE_DEFAULT_SIZE;
+    };
+}
+
+static int peer_attach(VirtIONet *n, int index)
+{
+    NetClientState *nc = qemu_get_subqueue(n->nic, index);
+
+    if (!nc->peer) {
+        return 0;
+    }
+
+    if (nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_USER) {
+        vhost_set_vring_enable(nc->peer, 1);
+    }
+
+    if (nc->peer->info->type != NET_CLIENT_DRIVER_TAP) {
+        return 0;
+    }
+
+    if (n->max_queue_pairs == 1) {
+        return 0;
+    }
+
+    return tap_enable(nc->peer);
+}
+
+static int peer_detach(VirtIONet *n, int index)
+{
+    NetClientState *nc = qemu_get_subqueue(n->nic, index);
+
+    if (!nc->peer) {
+        return 0;
+    }
+
+    if (nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_USER) {
+        vhost_set_vring_enable(nc->peer, 0);
+    }
+
+    if (nc->peer->info->type !=  NET_CLIENT_DRIVER_TAP) {
+        return 0;
+    }
+
+    return tap_disable(nc->peer);
+}
+
+static void virtio_net_set_queue_pairs(VirtIONet *n)
+{
+    int i;
+    int r;
+
+    if (n->nic->peer_deleted) {
+        return;
+    }
+
+    for (i = 0; i < n->max_queue_pairs; i++) {
+        if (i < n->curr_queue_pairs) {
+            r = peer_attach(n, i);
+            assert(!r);
+        } else {
+            r = peer_detach(n, i);
+            assert(!r);
+        }
+    }
+}
+
+static void virtio_net_set_multiqueue(VirtIONet *n, int multiqueue);
+
+static uint64_t virtio_net_get_features(VirtIODevice *vdev, uint64_t features,
+                                        Error **errp)
+{
+    VirtIONet *n = VIRTIO_NET(vdev);
+    NetClientState *nc = qemu_get_queue(n->nic);
+
+    /* Firstly sync all virtio-net possible supported features */
+    features |= n->host_features;
+
+    virtio_add_feature(&features, VIRTIO_NET_F_MAC);
+
+    if (!peer_has_vnet_hdr(n)) {
+        virtio_clear_feature(&features, VIRTIO_NET_F_CSUM);
+        virtio_clear_feature(&features, VIRTIO_NET_F_HOST_TSO4);
+        virtio_clear_feature(&features, VIRTIO_NET_F_HOST_TSO6);
+        virtio_clear_feature(&features, VIRTIO_NET_F_HOST_ECN);
+
+        virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_CSUM);
+        virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_TSO4);
+        virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_TSO6);
+        virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_ECN);
+
+        virtio_clear_feature(&features, VIRTIO_NET_F_HASH_REPORT);
+    }
+
+    if (!peer_has_vnet_hdr(n) || !peer_has_ufo(n)) {
+        virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_UFO);
+        virtio_clear_feature(&features, VIRTIO_NET_F_HOST_UFO);
+    }
+
+    if (!get_vhost_net(nc->peer)) {
+        virtio_add_feature(&features, VIRTIO_F_RING_RESET);
+        return features;
+    }
+
+    if (!ebpf_rss_is_loaded(&n->ebpf_rss)) {
+        virtio_clear_feature(&features, VIRTIO_NET_F_RSS);
+    }
+    features = vhost_net_get_features(get_vhost_net(nc->peer), features);
+    vdev->backend_features = features;
+
+    if (n->mtu_bypass_backend &&
+            (n->host_features & 1ULL << VIRTIO_NET_F_MTU)) {
+        features |= (1ULL << VIRTIO_NET_F_MTU);
+    }
+
+    return features;
+}
+
+static uint64_t virtio_net_bad_features(VirtIODevice *vdev)
+{
+    uint64_t features = 0;
+
+    /* Linux kernel 2.6.25.  It understood MAC (as everyone must),
+     * but also these: */
+    virtio_add_feature(&features, VIRTIO_NET_F_MAC);
+    virtio_add_feature(&features, VIRTIO_NET_F_CSUM);
+    virtio_add_feature(&features, VIRTIO_NET_F_HOST_TSO4);
+    virtio_add_feature(&features, VIRTIO_NET_F_HOST_TSO6);
+    virtio_add_feature(&features, VIRTIO_NET_F_HOST_ECN);
+
+    return features;
+}
+
+static void virtio_net_apply_guest_offloads(VirtIONet *n)
+{
+    qemu_set_offload(qemu_get_queue(n->nic)->peer,
+            !!(n->curr_guest_offloads & (1ULL << VIRTIO_NET_F_GUEST_CSUM)),
+            !!(n->curr_guest_offloads & (1ULL << VIRTIO_NET_F_GUEST_TSO4)),
+            !!(n->curr_guest_offloads & (1ULL << VIRTIO_NET_F_GUEST_TSO6)),
+            !!(n->curr_guest_offloads & (1ULL << VIRTIO_NET_F_GUEST_ECN)),
+            !!(n->curr_guest_offloads & (1ULL << VIRTIO_NET_F_GUEST_UFO)));
+}
+
+static uint64_t virtio_net_guest_offloads_by_features(uint32_t features)
+{
+    static const uint64_t guest_offloads_mask =
+        (1ULL << VIRTIO_NET_F_GUEST_CSUM) |
+        (1ULL << VIRTIO_NET_F_GUEST_TSO4) |
+        (1ULL << VIRTIO_NET_F_GUEST_TSO6) |
+        (1ULL << VIRTIO_NET_F_GUEST_ECN)  |
+        (1ULL << VIRTIO_NET_F_GUEST_UFO);
+
+    return guest_offloads_mask & features;
+}
+
+static inline uint64_t virtio_net_supported_guest_offloads(VirtIONet *n)
+{
+    VirtIODevice *vdev = VIRTIO_DEVICE(n);
+    return virtio_net_guest_offloads_by_features(vdev->guest_features);
+}
+
+typedef struct {
+    VirtIONet *n;
+    DeviceState *dev;
+} FailoverDevice;
+
+/**
+ * Set the failover primary device
+ *
+ * @opaque: FailoverId to setup
+ * @opts: opts for device we are handling
+ * @errp: returns an error if this function fails
+ */
+static int failover_set_primary(DeviceState *dev, void *opaque)
+{
+    FailoverDevice *fdev = opaque;
+    PCIDevice *pci_dev = (PCIDevice *)
+        object_dynamic_cast(OBJECT(dev), TYPE_PCI_DEVICE);
+
+    if (!pci_dev) {
+        return 0;
+    }
+
+    if (!g_strcmp0(pci_dev->failover_pair_id, fdev->n->netclient_name)) {
+        fdev->dev = dev;
+        return 1;
+    }
+
+    return 0;
+}
+
+/**
+ * Find the primary device for this failover virtio-net
+ *
+ * @n: VirtIONet device
+ * @errp: returns an error if this function fails
+ */
+static DeviceState *failover_find_primary_device(VirtIONet *n)
+{
+    FailoverDevice fdev = {
+        .n = n,
+    };
+
+    qbus_walk_children(sysbus_get_default(), failover_set_primary, NULL,
+                       NULL, NULL, &fdev);
+    return fdev.dev;
+}
+
+static void failover_add_primary(VirtIONet *n, Error **errp)
+{
+    Error *err = NULL;
+    DeviceState *dev = failover_find_primary_device(n);
+
+    if (dev) {
+        return;
+    }
+
+    if (!n->primary_opts) {
+        error_setg(errp, "Primary device not found");
+        error_append_hint(errp, "Virtio-net failover will not work. Make "
+                          "sure primary device has parameter"
+                          " failover_pair_id=%s\n", n->netclient_name);
+        return;
+    }
+
+    dev = qdev_device_add_from_qdict(n->primary_opts,
+                                     n->primary_opts_from_json,
+                                     &err);
+    if (err) {
+        qobject_unref(n->primary_opts);
+        n->primary_opts = NULL;
+    } else {
+        object_unref(OBJECT(dev));
+    }
+    error_propagate(errp, err);
+}
+
+static void virtio_net_set_features(VirtIODevice *vdev, uint64_t features)
+{
+    VirtIONet *n = VIRTIO_NET(vdev);
+    Error *err = NULL;
+    int i;
+
+    if (n->mtu_bypass_backend &&
+            !virtio_has_feature(vdev->backend_features, VIRTIO_NET_F_MTU)) {
+        features &= ~(1ULL << VIRTIO_NET_F_MTU);
+    }
+
+    virtio_net_set_multiqueue(n,
+                              virtio_has_feature(features, VIRTIO_NET_F_RSS) ||
+                              virtio_has_feature(features, VIRTIO_NET_F_MQ));
+
+    virtio_net_set_mrg_rx_bufs(n,
+                               virtio_has_feature(features,
+                                                  VIRTIO_NET_F_MRG_RXBUF),
+                               virtio_has_feature(features,
+                                                  VIRTIO_F_VERSION_1),
+                               virtio_has_feature(features,
+                                                  VIRTIO_NET_F_HASH_REPORT));
+
+    n->rsc4_enabled = virtio_has_feature(features, VIRTIO_NET_F_RSC_EXT) &&
+        virtio_has_feature(features, VIRTIO_NET_F_GUEST_TSO4);
+    n->rsc6_enabled = virtio_has_feature(features, VIRTIO_NET_F_RSC_EXT) &&
+        virtio_has_feature(features, VIRTIO_NET_F_GUEST_TSO6);
+    n->rss_data.redirect = virtio_has_feature(features, VIRTIO_NET_F_RSS);
+
+    if (n->has_vnet_hdr) {
+        n->curr_guest_offloads =
+            virtio_net_guest_offloads_by_features(features);
+        virtio_net_apply_guest_offloads(n);
+    }
+
+    for (i = 0;  i < n->max_queue_pairs; i++) {
+        NetClientState *nc = qemu_get_subqueue(n->nic, i);
+
+        if (!get_vhost_net(nc->peer)) {
+            continue;
+        }
+        vhost_net_ack_features(get_vhost_net(nc->peer), features);
+    }
+
+    if (virtio_has_feature(features, VIRTIO_NET_F_CTRL_VLAN)) {
+        memset(n->vlans, 0, MAX_VLAN >> 3);
+    } else {
+        memset(n->vlans, 0xff, MAX_VLAN >> 3);
+    }
+
+    if (virtio_has_feature(features, VIRTIO_NET_F_STANDBY)) {
+        qapi_event_send_failover_negotiated(n->netclient_name);
+        qatomic_set(&n->failover_primary_hidden, false);
+        failover_add_primary(n, &err);
+        if (err) {
+            if (!qtest_enabled()) {
+                warn_report_err(err);
+            } else {
+                error_free(err);
+            }
+        }
+    }
+}
+
+static int virtio_net_handle_rx_mode(VirtIONet *n, uint8_t cmd,
+                                     struct iovec *iov, unsigned int iov_cnt)
+{
+    uint8_t on;
+    size_t s;
+    NetClientState *nc = qemu_get_queue(n->nic);
+
+    s = iov_to_buf(iov, iov_cnt, 0, &on, sizeof(on));
+    if (s != sizeof(on)) {
+        return VIRTIO_NET_ERR;
+    }
+
+    if (cmd == VIRTIO_NET_CTRL_RX_PROMISC) {
+        n->promisc = on;
+    } else if (cmd == VIRTIO_NET_CTRL_RX_ALLMULTI) {
+        n->allmulti = on;
+    } else if (cmd == VIRTIO_NET_CTRL_RX_ALLUNI) {
+        n->alluni = on;
+    } else if (cmd == VIRTIO_NET_CTRL_RX_NOMULTI) {
+        n->nomulti = on;
+    } else if (cmd == VIRTIO_NET_CTRL_RX_NOUNI) {
+        n->nouni = on;
+    } else if (cmd == VIRTIO_NET_CTRL_RX_NOBCAST) {
+        n->nobcast = on;
+    } else {
+        return VIRTIO_NET_ERR;
+    }
+
+    rxfilter_notify(nc);
+
+    return VIRTIO_NET_OK;
+}
+
+static int virtio_net_handle_offloads(VirtIONet *n, uint8_t cmd,
+                                     struct iovec *iov, unsigned int iov_cnt)
+{
+    VirtIODevice *vdev = VIRTIO_DEVICE(n);
+    uint64_t offloads;
+    size_t s;
+
+    if (!virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS)) {
+        return VIRTIO_NET_ERR;
+    }
+
+    s = iov_to_buf(iov, iov_cnt, 0, &offloads, sizeof(offloads));
+    if (s != sizeof(offloads)) {
+        return VIRTIO_NET_ERR;
+    }
+
+    if (cmd == VIRTIO_NET_CTRL_GUEST_OFFLOADS_SET) {
+        uint64_t supported_offloads;
+
+        offloads = virtio_ldq_p(vdev, &offloads);
+
+        if (!n->has_vnet_hdr) {
+            return VIRTIO_NET_ERR;
+        }
+
+        n->rsc4_enabled = virtio_has_feature(offloads, VIRTIO_NET_F_RSC_EXT) &&
+            virtio_has_feature(offloads, VIRTIO_NET_F_GUEST_TSO4);
+        n->rsc6_enabled = virtio_has_feature(offloads, VIRTIO_NET_F_RSC_EXT) &&
+            virtio_has_feature(offloads, VIRTIO_NET_F_GUEST_TSO6);
+        virtio_clear_feature(&offloads, VIRTIO_NET_F_RSC_EXT);
+
+        supported_offloads = virtio_net_supported_guest_offloads(n);
+        if (offloads & ~supported_offloads) {
+            return VIRTIO_NET_ERR;
+        }
+
+        n->curr_guest_offloads = offloads;
+        virtio_net_apply_guest_offloads(n);
+
+        return VIRTIO_NET_OK;
+    } else {
+        return VIRTIO_NET_ERR;
+    }
+}
+
+static int virtio_net_handle_mac(VirtIONet *n, uint8_t cmd,
+                                 struct iovec *iov, unsigned int iov_cnt)
+{
+    VirtIODevice *vdev = VIRTIO_DEVICE(n);
+    struct virtio_net_ctrl_mac mac_data;
+    size_t s;
+    NetClientState *nc = qemu_get_queue(n->nic);
+
+    if (cmd == VIRTIO_NET_CTRL_MAC_ADDR_SET) {
+        if (iov_size(iov, iov_cnt) != sizeof(n->mac)) {
+            return VIRTIO_NET_ERR;
+        }
+        s = iov_to_buf(iov, iov_cnt, 0, &n->mac, sizeof(n->mac));
+        assert(s == sizeof(n->mac));
+        qemu_format_nic_info_str(qemu_get_queue(n->nic), n->mac);
+        rxfilter_notify(nc);
+
+        return VIRTIO_NET_OK;
+    }
+
+    if (cmd != VIRTIO_NET_CTRL_MAC_TABLE_SET) {
+        return VIRTIO_NET_ERR;
+    }
+
+    int in_use = 0;
+    int first_multi = 0;
+    uint8_t uni_overflow = 0;
+    uint8_t multi_overflow = 0;
+    uint8_t *macs = g_malloc0(MAC_TABLE_ENTRIES * ETH_ALEN);
+
+    s = iov_to_buf(iov, iov_cnt, 0, &mac_data.entries,
+                   sizeof(mac_data.entries));
+    mac_data.entries = virtio_ldl_p(vdev, &mac_data.entries);
+    if (s != sizeof(mac_data.entries)) {
+        goto error;
+    }
+    iov_discard_front(&iov, &iov_cnt, s);
+
+    if (mac_data.entries * ETH_ALEN > iov_size(iov, iov_cnt)) {
+        goto error;
+    }
+
+    if (mac_data.entries <= MAC_TABLE_ENTRIES) {
+        s = iov_to_buf(iov, iov_cnt, 0, macs,
+                       mac_data.entries * ETH_ALEN);
+        if (s != mac_data.entries * ETH_ALEN) {
+            goto error;
+        }
+        in_use += mac_data.entries;
+    } else {
+        uni_overflow = 1;
+    }
+
+    iov_discard_front(&iov, &iov_cnt, mac_data.entries * ETH_ALEN);
+
+    first_multi = in_use;
+
+    s = iov_to_buf(iov, iov_cnt, 0, &mac_data.entries,
+                   sizeof(mac_data.entries));
+    mac_data.entries = virtio_ldl_p(vdev, &mac_data.entries);
+    if (s != sizeof(mac_data.entries)) {
+        goto error;
+    }
+
+    iov_discard_front(&iov, &iov_cnt, s);
+
+    if (mac_data.entries * ETH_ALEN != iov_size(iov, iov_cnt)) {
+        goto error;
+    }
+
+    if (mac_data.entries <= MAC_TABLE_ENTRIES - in_use) {
+        s = iov_to_buf(iov, iov_cnt, 0, &macs[in_use * ETH_ALEN],
+                       mac_data.entries * ETH_ALEN);
+        if (s != mac_data.entries * ETH_ALEN) {
+            goto error;
+        }
+        in_use += mac_data.entries;
+    } else {
+        multi_overflow = 1;
+    }
+
+    n->mac_table.in_use = in_use;
+    n->mac_table.first_multi = first_multi;
+    n->mac_table.uni_overflow = uni_overflow;
+    n->mac_table.multi_overflow = multi_overflow;
+    memcpy(n->mac_table.macs, macs, MAC_TABLE_ENTRIES * ETH_ALEN);
+    g_free(macs);
+    rxfilter_notify(nc);
+
+    return VIRTIO_NET_OK;
+
+error:
+    g_free(macs);
+    return VIRTIO_NET_ERR;
+}
+
+static int virtio_net_handle_vlan_table(VirtIONet *n, uint8_t cmd,
+                                        struct iovec *iov, unsigned int iov_cnt)
+{
+    VirtIODevice *vdev = VIRTIO_DEVICE(n);
+    uint16_t vid;
+    size_t s;
+    NetClientState *nc = qemu_get_queue(n->nic);
+
+    s = iov_to_buf(iov, iov_cnt, 0, &vid, sizeof(vid));
+    vid = virtio_lduw_p(vdev, &vid);
+    if (s != sizeof(vid)) {
+        return VIRTIO_NET_ERR;
+    }
+
+    if (vid >= MAX_VLAN)
+        return VIRTIO_NET_ERR;
+
+    if (cmd == VIRTIO_NET_CTRL_VLAN_ADD)
+        n->vlans[vid >> 5] |= (1U << (vid & 0x1f));
+    else if (cmd == VIRTIO_NET_CTRL_VLAN_DEL)
+        n->vlans[vid >> 5] &= ~(1U << (vid & 0x1f));
+    else
+        return VIRTIO_NET_ERR;
+
+    rxfilter_notify(nc);
+
+    return VIRTIO_NET_OK;
+}
+
+static int virtio_net_handle_announce(VirtIONet *n, uint8_t cmd,
+                                      struct iovec *iov, unsigned int iov_cnt)
+{
+    trace_virtio_net_handle_announce(n->announce_timer.round);
+    if (cmd == VIRTIO_NET_CTRL_ANNOUNCE_ACK &&
+        n->status & VIRTIO_NET_S_ANNOUNCE) {
+        n->status &= ~VIRTIO_NET_S_ANNOUNCE;
+        if (n->announce_timer.round) {
+            qemu_announce_timer_step(&n->announce_timer);
+        }
+        return VIRTIO_NET_OK;
+    } else {
+        return VIRTIO_NET_ERR;
+    }
+}
+
+static void virtio_net_detach_epbf_rss(VirtIONet *n);
+
+static void virtio_net_disable_rss(VirtIONet *n)
+{
+    if (n->rss_data.enabled) {
+        trace_virtio_net_rss_disable();
+    }
+    n->rss_data.enabled = false;
+
+    virtio_net_detach_epbf_rss(n);
+}
+
+static bool virtio_net_attach_ebpf_to_backend(NICState *nic, int prog_fd)
+{
+    NetClientState *nc = qemu_get_peer(qemu_get_queue(nic), 0);
+    if (nc == NULL || nc->info->set_steering_ebpf == NULL) {
+        return false;
+    }
+
+    return nc->info->set_steering_ebpf(nc, prog_fd);
+}
+
+static void rss_data_to_rss_config(struct VirtioNetRssData *data,
+                                   struct EBPFRSSConfig *config)
+{
+    config->redirect = data->redirect;
+    config->populate_hash = data->populate_hash;
+    config->hash_types = data->hash_types;
+    config->indirections_len = data->indirections_len;
+    config->default_queue = data->default_queue;
+}
+
+static bool virtio_net_attach_epbf_rss(VirtIONet *n)
+{
+    struct EBPFRSSConfig config = {};
+
+    if (!ebpf_rss_is_loaded(&n->ebpf_rss)) {
+        return false;
+    }
+
+    rss_data_to_rss_config(&n->rss_data, &config);
+
+    if (!ebpf_rss_set_all(&n->ebpf_rss, &config,
+                          n->rss_data.indirections_table, n->rss_data.key)) {
+        return false;
+    }
+
+    if (!virtio_net_attach_ebpf_to_backend(n->nic, n->ebpf_rss.program_fd)) {
+        return false;
+    }
+
+    return true;
+}
+
+static void virtio_net_detach_epbf_rss(VirtIONet *n)
+{
+    virtio_net_attach_ebpf_to_backend(n->nic, -1);
+}
+
+static bool virtio_net_load_ebpf(VirtIONet *n)
+{
+    if (!virtio_net_attach_ebpf_to_backend(n->nic, -1)) {
+        /* backend does't support steering ebpf */
+        return false;
+    }
+
+    return ebpf_rss_load(&n->ebpf_rss);
+}
+
+static void virtio_net_unload_ebpf(VirtIONet *n)
+{
+    virtio_net_attach_ebpf_to_backend(n->nic, -1);
+    ebpf_rss_unload(&n->ebpf_rss);
+}
+
+static uint16_t virtio_net_handle_rss(VirtIONet *n,
+                                      struct iovec *iov,
+                                      unsigned int iov_cnt,
+                                      bool do_rss)
+{
+    VirtIODevice *vdev = VIRTIO_DEVICE(n);
+    struct virtio_net_rss_config cfg;
+    size_t s, offset = 0, size_get;
+    uint16_t queue_pairs, i;
+    struct {
+        uint16_t us;
+        uint8_t b;
+    } QEMU_PACKED temp;
+    const char *err_msg = "";
+    uint32_t err_value = 0;
+
+    if (do_rss && !virtio_vdev_has_feature(vdev, VIRTIO_NET_F_RSS)) {
+        err_msg = "RSS is not negotiated";
+        goto error;
+    }
+    if (!do_rss && !virtio_vdev_has_feature(vdev, VIRTIO_NET_F_HASH_REPORT)) {
+        err_msg = "Hash report is not negotiated";
+        goto error;
+    }
+    size_get = offsetof(struct virtio_net_rss_config, indirection_table);
+    s = iov_to_buf(iov, iov_cnt, offset, &cfg, size_get);
+    if (s != size_get) {
+        err_msg = "Short command buffer";
+        err_value = (uint32_t)s;
+        goto error;
+    }
+    n->rss_data.hash_types = virtio_ldl_p(vdev, &cfg.hash_types);
+    n->rss_data.indirections_len =
+        virtio_lduw_p(vdev, &cfg.indirection_table_mask);
+    n->rss_data.indirections_len++;
+    if (!do_rss) {
+        n->rss_data.indirections_len = 1;
+    }
+    if (!is_power_of_2(n->rss_data.indirections_len)) {
+        err_msg = "Invalid size of indirection table";
+        err_value = n->rss_data.indirections_len;
+        goto error;
+    }
+    if (n->rss_data.indirections_len > VIRTIO_NET_RSS_MAX_TABLE_LEN) {
+        err_msg = "Too large indirection table";
+        err_value = n->rss_data.indirections_len;
+        goto error;
+    }
+    n->rss_data.default_queue = do_rss ?
+        virtio_lduw_p(vdev, &cfg.unclassified_queue) : 0;
+    if (n->rss_data.default_queue >= n->max_queue_pairs) {
+        err_msg = "Invalid default queue";
+        err_value = n->rss_data.default_queue;
+        goto error;
+    }
+    offset += size_get;
+    size_get = sizeof(uint16_t) * n->rss_data.indirections_len;
+    g_free(n->rss_data.indirections_table);
+    n->rss_data.indirections_table = g_malloc(size_get);
+    if (!n->rss_data.indirections_table) {
+        err_msg = "Can't allocate indirections table";
+        err_value = n->rss_data.indirections_len;
+        goto error;
+    }
+    s = iov_to_buf(iov, iov_cnt, offset,
+                   n->rss_data.indirections_table, size_get);
+    if (s != size_get) {
+        err_msg = "Short indirection table buffer";
+        err_value = (uint32_t)s;
+        goto error;
+    }
+    for (i = 0; i < n->rss_data.indirections_len; ++i) {
+        uint16_t val = n->rss_data.indirections_table[i];
+        n->rss_data.indirections_table[i] = virtio_lduw_p(vdev, &val);
+    }
+    offset += size_get;
+    size_get = sizeof(temp);
+    s = iov_to_buf(iov, iov_cnt, offset, &temp, size_get);
+    if (s != size_get) {
+        err_msg = "Can't get queue_pairs";
+        err_value = (uint32_t)s;
+        goto error;
+    }
+    queue_pairs = do_rss ? virtio_lduw_p(vdev, &temp.us) : n->curr_queue_pairs;
+    if (queue_pairs == 0 || queue_pairs > n->max_queue_pairs) {
+        err_msg = "Invalid number of queue_pairs";
+        err_value = queue_pairs;
+        goto error;
+    }
+    if (temp.b > VIRTIO_NET_RSS_MAX_KEY_SIZE) {
+        err_msg = "Invalid key size";
+        err_value = temp.b;
+        goto error;
+    }
+    if (!temp.b && n->rss_data.hash_types) {
+        err_msg = "No key provided";
+        err_value = 0;
+        goto error;
+    }
+    if (!temp.b && !n->rss_data.hash_types) {
+        virtio_net_disable_rss(n);
+        return queue_pairs;
+    }
+    offset += size_get;
+    size_get = temp.b;
+    s = iov_to_buf(iov, iov_cnt, offset, n->rss_data.key, size_get);
+    if (s != size_get) {
+        err_msg = "Can get key buffer";
+        err_value = (uint32_t)s;
+        goto error;
+    }
+    n->rss_data.enabled = true;
+
+    if (!n->rss_data.populate_hash) {
+        if (!virtio_net_attach_epbf_rss(n)) {
+            /* EBPF must be loaded for vhost */
+            if (get_vhost_net(qemu_get_queue(n->nic)->peer)) {
+                warn_report("Can't load eBPF RSS for vhost");
+                goto error;
+            }
+            /* fallback to software RSS */
+            warn_report("Can't load eBPF RSS - fallback to software RSS");
+            n->rss_data.enabled_software_rss = true;
+        }
+    } else {
+        /* use software RSS for hash populating */
+        /* and detach eBPF if was loaded before */
+        virtio_net_detach_epbf_rss(n);
+        n->rss_data.enabled_software_rss = true;
+    }
+
+    trace_virtio_net_rss_enable(n->rss_data.hash_types,
+                                n->rss_data.indirections_len,
+                                temp.b);
+    return queue_pairs;
+error:
+    trace_virtio_net_rss_error(err_msg, err_value);
+    virtio_net_disable_rss(n);
+    return 0;
+}
+
+static int virtio_net_handle_mq(VirtIONet *n, uint8_t cmd,
+                                struct iovec *iov, unsigned int iov_cnt)
+{
+    VirtIODevice *vdev = VIRTIO_DEVICE(n);
+    uint16_t queue_pairs;
+    NetClientState *nc = qemu_get_queue(n->nic);
+
+    virtio_net_disable_rss(n);
+    if (cmd == VIRTIO_NET_CTRL_MQ_HASH_CONFIG) {
+        queue_pairs = virtio_net_handle_rss(n, iov, iov_cnt, false);
+        return queue_pairs ? VIRTIO_NET_OK : VIRTIO_NET_ERR;
+    }
+    if (cmd == VIRTIO_NET_CTRL_MQ_RSS_CONFIG) {
+        queue_pairs = virtio_net_handle_rss(n, iov, iov_cnt, true);
+    } else if (cmd == VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET) {
+        struct virtio_net_ctrl_mq mq;
+        size_t s;
+        if (!virtio_vdev_has_feature(vdev, VIRTIO_NET_F_MQ)) {
+            return VIRTIO_NET_ERR;
+        }
+        s = iov_to_buf(iov, iov_cnt, 0, &mq, sizeof(mq));
+        if (s != sizeof(mq)) {
+            return VIRTIO_NET_ERR;
+        }
+        queue_pairs = virtio_lduw_p(vdev, &mq.virtqueue_pairs);
+
+    } else {
+        return VIRTIO_NET_ERR;
+    }
+
+    if (queue_pairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
+        queue_pairs > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX ||
+        queue_pairs > n->max_queue_pairs ||
+        !n->multiqueue) {
+        return VIRTIO_NET_ERR;
+    }
+
+    n->curr_queue_pairs = queue_pairs;
+    if (nc->peer && nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_VDPA) {
+        /*
+         * Avoid updating the backend for a vdpa device: We're only interested
+         * in updating the device model queues.
+         */
+        return VIRTIO_NET_OK;
+    }
+    /* stop the backend before changing the number of queue_pairs to avoid handling a
+     * disabled queue */
+    virtio_net_set_status(vdev, vdev->status);
+    virtio_net_set_queue_pairs(n);
+
+    return VIRTIO_NET_OK;
+}
+
+size_t virtio_net_handle_ctrl_iov(VirtIODevice *vdev,
+                                  const struct iovec *in_sg, unsigned in_num,
+                                  const struct iovec *out_sg,
+                                  unsigned out_num)
+{
+    VirtIONet *n = VIRTIO_NET(vdev);
+    struct virtio_net_ctrl_hdr ctrl;
+    virtio_net_ctrl_ack status = VIRTIO_NET_ERR;
+    size_t s;
+    struct iovec *iov, *iov2;
+
+    if (iov_size(in_sg, in_num) < sizeof(status) ||
+        iov_size(out_sg, out_num) < sizeof(ctrl)) {
+        virtio_error(vdev, "virtio-net ctrl missing headers");
+        return 0;
+    }
+
+    iov2 = iov = g_memdup2(out_sg, sizeof(struct iovec) * out_num);
+    s = iov_to_buf(iov, out_num, 0, &ctrl, sizeof(ctrl));
+    iov_discard_front(&iov, &out_num, sizeof(ctrl));
+    if (s != sizeof(ctrl)) {
+        status = VIRTIO_NET_ERR;
+    } else if (ctrl.class == VIRTIO_NET_CTRL_RX) {
+        status = virtio_net_handle_rx_mode(n, ctrl.cmd, iov, out_num);
+    } else if (ctrl.class == VIRTIO_NET_CTRL_MAC) {
+        status = virtio_net_handle_mac(n, ctrl.cmd, iov, out_num);
+    } else if (ctrl.class == VIRTIO_NET_CTRL_VLAN) {
+        status = virtio_net_handle_vlan_table(n, ctrl.cmd, iov, out_num);
+    } else if (ctrl.class == VIRTIO_NET_CTRL_ANNOUNCE) {
+        status = virtio_net_handle_announce(n, ctrl.cmd, iov, out_num);
+    } else if (ctrl.class == VIRTIO_NET_CTRL_MQ) {
+        status = virtio_net_handle_mq(n, ctrl.cmd, iov, out_num);
+    } else if (ctrl.class == VIRTIO_NET_CTRL_GUEST_OFFLOADS) {
+        status = virtio_net_handle_offloads(n, ctrl.cmd, iov, out_num);
+    }
+
+    s = iov_from_buf(in_sg, in_num, 0, &status, sizeof(status));
+    assert(s == sizeof(status));
+
+    g_free(iov2);
+    return sizeof(status);
+}
+
+static void virtio_net_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
+{
+    VirtQueueElement *elem;
+
+    for (;;) {
+        size_t written;
+        elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
+        if (!elem) {
+            break;
+        }
+
+        written = virtio_net_handle_ctrl_iov(vdev, elem->in_sg, elem->in_num,
+                                             elem->out_sg, elem->out_num);
+        if (written > 0) {
+            virtqueue_push(vq, elem, written);
+            virtio_notify(vdev, vq);
+            g_free(elem);
+        } else {
+            virtqueue_detach_element(vq, elem, 0);
+            g_free(elem);
+            break;
+        }
+    }
+}
+
+/* RX */
+
+static void virtio_net_handle_rx(VirtIODevice *vdev, VirtQueue *vq)
+{
+    VirtIONet *n = VIRTIO_NET(vdev);
+    int queue_index = vq2q(virtio_get_queue_index(vq));
+
+    qemu_flush_queued_packets(qemu_get_subqueue(n->nic, queue_index));
+}
+
+static bool virtio_net_can_receive(NetClientState *nc)
+{
+    VirtIONet *n = qemu_get_nic_opaque(nc);
+    VirtIODevice *vdev = VIRTIO_DEVICE(n);
+    VirtIONetQueue *q = virtio_net_get_subqueue(nc);
+
+    if (!vdev->vm_running) {
+        return false;
+    }
+
+    if (nc->queue_index >= n->curr_queue_pairs) {
+        return false;
+    }
+
+    if (!virtio_queue_ready(q->rx_vq) ||
+        !(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) {
+        return false;
+    }
+
+    return true;
+}
+
+static int virtio_net_has_buffers(VirtIONetQueue *q, int bufsize)
+{
+    VirtIONet *n = q->n;
+    if (virtio_queue_empty(q->rx_vq) ||
+        (n->mergeable_rx_bufs &&
+         !virtqueue_avail_bytes(q->rx_vq, bufsize, 0))) {
+        virtio_queue_set_notification(q->rx_vq, 1);
+
+        /* To avoid a race condition where the guest has made some buffers
+         * available after the above check but before notification was
+         * enabled, check for available buffers again.
+         */
+        if (virtio_queue_empty(q->rx_vq) ||
+            (n->mergeable_rx_bufs &&
+             !virtqueue_avail_bytes(q->rx_vq, bufsize, 0))) {
+            return 0;
+        }
+    }
+
+    virtio_queue_set_notification(q->rx_vq, 0);
+    return 1;
+}
+
+static void virtio_net_hdr_swap(VirtIODevice *vdev, struct virtio_net_hdr *hdr)
+{
+    virtio_tswap16s(vdev, &hdr->hdr_len);
+    virtio_tswap16s(vdev, &hdr->gso_size);
+    virtio_tswap16s(vdev, &hdr->csum_start);
+    virtio_tswap16s(vdev, &hdr->csum_offset);
+}
+
+/* dhclient uses AF_PACKET but doesn't pass auxdata to the kernel so
+ * it never finds out that the packets don't have valid checksums.  This
+ * causes dhclient to get upset.  Fedora's carried a patch for ages to
+ * fix this with Xen but it hasn't appeared in an upstream release of
+ * dhclient yet.
+ *
+ * To avoid breaking existing guests, we catch udp packets and add
+ * checksums.  This is terrible but it's better than hacking the guest
+ * kernels.
+ *
+ * N.B. if we introduce a zero-copy API, this operation is no longer free so
+ * we should provide a mechanism to disable it to avoid polluting the host
+ * cache.
+ */
+static void work_around_broken_dhclient(struct virtio_net_hdr *hdr,
+                                        uint8_t *buf, size_t size)
+{
+    if ((hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && /* missing csum */
+        (size > 27 && size < 1500) && /* normal sized MTU */
+        (buf[12] == 0x08 && buf[13] == 0x00) && /* ethertype == IPv4 */
+        (buf[23] == 17) && /* ip.protocol == UDP */
+        (buf[34] == 0 && buf[35] == 67)) { /* udp.srcport == bootps */
+        net_checksum_calculate(buf, size, CSUM_UDP);
+        hdr->flags &= ~VIRTIO_NET_HDR_F_NEEDS_CSUM;
+    }
+}
+
+static void receive_header(VirtIONet *n, const struct iovec *iov, int iov_cnt,
+                           const void *buf, size_t size)
+{
+    if (n->has_vnet_hdr) {
+        /* FIXME this cast is evil */
+        void *wbuf = (void *)buf;
+        work_around_broken_dhclient(wbuf, wbuf + n->host_hdr_len,
+                                    size - n->host_hdr_len);
+
+        if (n->needs_vnet_hdr_swap) {
+            virtio_net_hdr_swap(VIRTIO_DEVICE(n), wbuf);
+        }
+        iov_from_buf(iov, iov_cnt, 0, buf, sizeof(struct virtio_net_hdr));
+    } else {
+        struct virtio_net_hdr hdr = {
+            .flags = 0,
+            .gso_type = VIRTIO_NET_HDR_GSO_NONE
+        };
+        iov_from_buf(iov, iov_cnt, 0, &hdr, sizeof hdr);
+    }
+}
+
+static int receive_filter(VirtIONet *n, const uint8_t *buf, int size)
+{
+    static const uint8_t bcast[] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
+    static const uint8_t vlan[] = {0x81, 0x00};
+    uint8_t *ptr = (uint8_t *)buf;
+    int i;
+
+    if (n->promisc)
+        return 1;
+
+    ptr += n->host_hdr_len;
+
+    if (!memcmp(&ptr[12], vlan, sizeof(vlan))) {
+        int vid = lduw_be_p(ptr + 14) & 0xfff;
+        if (!(n->vlans[vid >> 5] & (1U << (vid & 0x1f))))
+            return 0;
+    }
+
+    if (ptr[0] & 1) { // multicast
+        if (!memcmp(ptr, bcast, sizeof(bcast))) {
+            return !n->nobcast;
+        } else if (n->nomulti) {
+            return 0;
+        } else if (n->allmulti || n->mac_table.multi_overflow) {
+            return 1;
+        }
+
+        for (i = n->mac_table.first_multi; i < n->mac_table.in_use; i++) {
+            if (!memcmp(ptr, &n->mac_table.macs[i * ETH_ALEN], ETH_ALEN)) {
+                return 1;
+            }
+        }
+    } else { // unicast
+        if (n->nouni) {
+            return 0;
+        } else if (n->alluni || n->mac_table.uni_overflow) {
+            return 1;
+        } else if (!memcmp(ptr, n->mac, ETH_ALEN)) {
+            return 1;
+        }
+
+        for (i = 0; i < n->mac_table.first_multi; i++) {
+            if (!memcmp(ptr, &n->mac_table.macs[i * ETH_ALEN], ETH_ALEN)) {
+                return 1;
+            }
+        }
+    }
+
+    return 0;
+}
+
+static uint8_t virtio_net_get_hash_type(bool isip4,
+                                        bool isip6,
+                                        bool isudp,
+                                        bool istcp,
+                                        uint32_t types)
+{
+    if (isip4) {
+        if (istcp && (types & VIRTIO_NET_RSS_HASH_TYPE_TCPv4)) {
+            return NetPktRssIpV4Tcp;
+        }
+        if (isudp && (types & VIRTIO_NET_RSS_HASH_TYPE_UDPv4)) {
+            return NetPktRssIpV4Udp;
+        }
+        if (types & VIRTIO_NET_RSS_HASH_TYPE_IPv4) {
+            return NetPktRssIpV4;
+        }
+    } else if (isip6) {
+        uint32_t mask = VIRTIO_NET_RSS_HASH_TYPE_TCP_EX |
+                        VIRTIO_NET_RSS_HASH_TYPE_TCPv6;
+
+        if (istcp && (types & mask)) {
+            return (types & VIRTIO_NET_RSS_HASH_TYPE_TCP_EX) ?
+                NetPktRssIpV6TcpEx : NetPktRssIpV6Tcp;
+        }
+        mask = VIRTIO_NET_RSS_HASH_TYPE_UDP_EX | VIRTIO_NET_RSS_HASH_TYPE_UDPv6;
+        if (isudp && (types & mask)) {
+            return (types & VIRTIO_NET_RSS_HASH_TYPE_UDP_EX) ?
+                NetPktRssIpV6UdpEx : NetPktRssIpV6Udp;
+        }
+        mask = VIRTIO_NET_RSS_HASH_TYPE_IP_EX | VIRTIO_NET_RSS_HASH_TYPE_IPv6;
+        if (types & mask) {
+            return (types & VIRTIO_NET_RSS_HASH_TYPE_IP_EX) ?
+                NetPktRssIpV6Ex : NetPktRssIpV6;
+        }
+    }
+    return 0xff;
+}
+
+static void virtio_set_packet_hash(const uint8_t *buf, uint8_t report,
+                                   uint32_t hash)
+{
+    struct virtio_net_hdr_v1_hash *hdr = (void *)buf;
+    hdr->hash_value = hash;
+    hdr->hash_report = report;
+}
+
+static int virtio_net_process_rss(NetClientState *nc, const uint8_t *buf,
+                                  size_t size)
+{
+    VirtIONet *n = qemu_get_nic_opaque(nc);
+    unsigned int index = nc->queue_index, new_index = index;
+    struct NetRxPkt *pkt = n->rx_pkt;
+    uint8_t net_hash_type;
+    uint32_t hash;
+    bool isip4, isip6, isudp, istcp;
+    static const uint8_t reports[NetPktRssIpV6UdpEx + 1] = {
+        VIRTIO_NET_HASH_REPORT_IPv4,
+        VIRTIO_NET_HASH_REPORT_TCPv4,
+        VIRTIO_NET_HASH_REPORT_TCPv6,
+        VIRTIO_NET_HASH_REPORT_IPv6,
+        VIRTIO_NET_HASH_REPORT_IPv6_EX,
+        VIRTIO_NET_HASH_REPORT_TCPv6_EX,
+        VIRTIO_NET_HASH_REPORT_UDPv4,
+        VIRTIO_NET_HASH_REPORT_UDPv6,
+        VIRTIO_NET_HASH_REPORT_UDPv6_EX
+    };
+
+    net_rx_pkt_set_protocols(pkt, buf + n->host_hdr_len,
+                             size - n->host_hdr_len);
+    net_rx_pkt_get_protocols(pkt, &isip4, &isip6, &isudp, &istcp);
+    if (isip4 && (net_rx_pkt_get_ip4_info(pkt)->fragment)) {
+        istcp = isudp = false;
+    }
+    if (isip6 && (net_rx_pkt_get_ip6_info(pkt)->fragment)) {
+        istcp = isudp = false;
+    }
+    net_hash_type = virtio_net_get_hash_type(isip4, isip6, isudp, istcp,
+                                             n->rss_data.hash_types);
+    if (net_hash_type > NetPktRssIpV6UdpEx) {
+        if (n->rss_data.populate_hash) {
+            virtio_set_packet_hash(buf, VIRTIO_NET_HASH_REPORT_NONE, 0);
+        }
+        return n->rss_data.redirect ? n->rss_data.default_queue : -1;
+    }
+
+    hash = net_rx_pkt_calc_rss_hash(pkt, net_hash_type, n->rss_data.key);
+
+    if (n->rss_data.populate_hash) {
+        virtio_set_packet_hash(buf, reports[net_hash_type], hash);
+    }
+
+    if (n->rss_data.redirect) {
+        new_index = hash & (n->rss_data.indirections_len - 1);
+        new_index = n->rss_data.indirections_table[new_index];
+    }
+
+    return (index == new_index) ? -1 : new_index;
+}
+
+static ssize_t virtio_net_receive_rcu(NetClientState *nc, const uint8_t *buf,
+                                      size_t size, bool no_rss)
+{
+    VirtIONet *n = qemu_get_nic_opaque(nc);
+    VirtIONetQueue *q = virtio_net_get_subqueue(nc);
+    VirtIODevice *vdev = VIRTIO_DEVICE(n);
+    VirtQueueElement *elems[VIRTQUEUE_MAX_SIZE];
+    size_t lens[VIRTQUEUE_MAX_SIZE];
+    struct iovec mhdr_sg[VIRTQUEUE_MAX_SIZE];
+    struct virtio_net_hdr_mrg_rxbuf mhdr;
+    unsigned mhdr_cnt = 0;
+    size_t offset, i, guest_offset, j;
+    ssize_t err;
+
+    if (!virtio_net_can_receive(nc)) {
+        return -1;
+    }
+
+    if (!no_rss && n->rss_data.enabled && n->rss_data.enabled_software_rss) {
+        int index = virtio_net_process_rss(nc, buf, size);
+        if (index >= 0) {
+            NetClientState *nc2 = qemu_get_subqueue(n->nic, index);
+            return virtio_net_receive_rcu(nc2, buf, size, true);
+        }
+    }
+
+    /* hdr_len refers to the header we supply to the guest */
+    if (!virtio_net_has_buffers(q, size + n->guest_hdr_len - n->host_hdr_len)) {
+        return 0;
+    }
+
+    if (!receive_filter(n, buf, size))
+        return size;
+
+    offset = i = 0;
+
+    while (offset < size) {
+        VirtQueueElement *elem;
+        int len, total;
+        const struct iovec *sg;
+
+        total = 0;
+
+        if (i == VIRTQUEUE_MAX_SIZE) {
+            virtio_error(vdev, "virtio-net unexpected long buffer chain");
+            err = size;
+            goto err;
+        }
+
+        elem = virtqueue_pop(q->rx_vq, sizeof(VirtQueueElement));
+        if (!elem) {
+            if (i) {
+                virtio_error(vdev, "virtio-net unexpected empty queue: "
+                             "i %zd mergeable %d offset %zd, size %zd, "
+                             "guest hdr len %zd, host hdr len %zd "
+                             "guest features 0x%" PRIx64,
+                             i, n->mergeable_rx_bufs, offset, size,
+                             n->guest_hdr_len, n->host_hdr_len,
+                             vdev->guest_features);
+            }
+            err = -1;
+            goto err;
+        }
+
+        if (elem->in_num < 1) {
+            virtio_error(vdev,
+                         "virtio-net receive queue contains no in buffers");
+            virtqueue_detach_element(q->rx_vq, elem, 0);
+            g_free(elem);
+            err = -1;
+            goto err;
+        }
+
+        sg = elem->in_sg;
+        if (i == 0) {
+            assert(offset == 0);
+            if (n->mergeable_rx_bufs) {
+                mhdr_cnt = iov_copy(mhdr_sg, ARRAY_SIZE(mhdr_sg),
+                                    sg, elem->in_num,
+                                    offsetof(typeof(mhdr), num_buffers),
+                                    sizeof(mhdr.num_buffers));
+            }
+
+            receive_header(n, sg, elem->in_num, buf, size);
+            if (n->rss_data.populate_hash) {
+                offset = sizeof(mhdr);
+                iov_from_buf(sg, elem->in_num, offset,
+                             buf + offset, n->host_hdr_len - sizeof(mhdr));
+            }
+            offset = n->host_hdr_len;
+            total += n->guest_hdr_len;
+            guest_offset = n->guest_hdr_len;
+        } else {
+            guest_offset = 0;
+        }
+
+        /* copy in packet.  ugh */
+        len = iov_from_buf(sg, elem->in_num, guest_offset,
+                           buf + offset, size - offset);
+        total += len;
+        offset += len;
+        /* If buffers can't be merged, at this point we
+         * must have consumed the complete packet.
+         * Otherwise, drop it. */
+        if (!n->mergeable_rx_bufs && offset < size) {
+            virtqueue_unpop(q->rx_vq, elem, total);
+            g_free(elem);
+            err = size;
+            goto err;
+        }
+
+        elems[i] = elem;
+        lens[i] = total;
+        i++;
+    }
+
+    if (mhdr_cnt) {
+        virtio_stw_p(vdev, &mhdr.num_buffers, i);
+        iov_from_buf(mhdr_sg, mhdr_cnt,
+                     0,
+                     &mhdr.num_buffers, sizeof mhdr.num_buffers);
+    }
+
+    for (j = 0; j < i; j++) {
+        /* signal other side */
+        virtqueue_fill(q->rx_vq, elems[j], lens[j], j);
+        g_free(elems[j]);
+    }
+
+    virtqueue_flush(q->rx_vq, i);
+    virtio_notify(vdev, q->rx_vq);
+
+    return size;
+
+err:
+    for (j = 0; j < i; j++) {
+        virtqueue_detach_element(q->rx_vq, elems[j], lens[j]);
+        g_free(elems[j]);
+    }
+
+    return err;
+}
+
+static ssize_t virtio_net_do_receive(NetClientState *nc, const uint8_t *buf,
+                                  size_t size)
+{
+    RCU_READ_LOCK_GUARD();
+
+    return virtio_net_receive_rcu(nc, buf, size, false);
+}
+
+static void virtio_net_rsc_extract_unit4(VirtioNetRscChain *chain,
+                                         const uint8_t *buf,
+                                         VirtioNetRscUnit *unit)
+{
+    uint16_t ip_hdrlen;
+    struct ip_header *ip;
+
+    ip = (struct ip_header *)(buf + chain->n->guest_hdr_len
+                              + sizeof(struct eth_header));
+    unit->ip = (void *)ip;
+    ip_hdrlen = (ip->ip_ver_len & 0xF) << 2;
+    unit->ip_plen = &ip->ip_len;
+    unit->tcp = (struct tcp_header *)(((uint8_t *)unit->ip) + ip_hdrlen);
+    unit->tcp_hdrlen = (htons(unit->tcp->th_offset_flags) & 0xF000) >> 10;
+    unit->payload = htons(*unit->ip_plen) - ip_hdrlen - unit->tcp_hdrlen;
+}
+
+static void virtio_net_rsc_extract_unit6(VirtioNetRscChain *chain,
+                                         const uint8_t *buf,
+                                         VirtioNetRscUnit *unit)
+{
+    struct ip6_header *ip6;
+
+    ip6 = (struct ip6_header *)(buf + chain->n->guest_hdr_len
+                                 + sizeof(struct eth_header));
+    unit->ip = ip6;
+    unit->ip_plen = &(ip6->ip6_ctlun.ip6_un1.ip6_un1_plen);
+    unit->tcp = (struct tcp_header *)(((uint8_t *)unit->ip)
+                                        + sizeof(struct ip6_header));
+    unit->tcp_hdrlen = (htons(unit->tcp->th_offset_flags) & 0xF000) >> 10;
+
+    /* There is a difference between payload lenght in ipv4 and v6,
+       ip header is excluded in ipv6 */
+    unit->payload = htons(*unit->ip_plen) - unit->tcp_hdrlen;
+}
+
+static size_t virtio_net_rsc_drain_seg(VirtioNetRscChain *chain,
+                                       VirtioNetRscSeg *seg)
+{
+    int ret;
+    struct virtio_net_hdr_v1 *h;
+
+    h = (struct virtio_net_hdr_v1 *)seg->buf;
+    h->flags = 0;
+    h->gso_type = VIRTIO_NET_HDR_GSO_NONE;
+
+    if (seg->is_coalesced) {
+        h->rsc.segments = seg->packets;
+        h->rsc.dup_acks = seg->dup_ack;
+        h->flags = VIRTIO_NET_HDR_F_RSC_INFO;
+        if (chain->proto == ETH_P_IP) {
+            h->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
+        } else {
+            h->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
+        }
+    }
+
+    ret = virtio_net_do_receive(seg->nc, seg->buf, seg->size);
+    QTAILQ_REMOVE(&chain->buffers, seg, next);
+    g_free(seg->buf);
+    g_free(seg);
+
+    return ret;
+}
+
+static void virtio_net_rsc_purge(void *opq)
+{
+    VirtioNetRscSeg *seg, *rn;
+    VirtioNetRscChain *chain = (VirtioNetRscChain *)opq;
+
+    QTAILQ_FOREACH_SAFE(seg, &chain->buffers, next, rn) {
+        if (virtio_net_rsc_drain_seg(chain, seg) == 0) {
+            chain->stat.purge_failed++;
+            continue;
+        }
+    }
+
+    chain->stat.timer++;
+    if (!QTAILQ_EMPTY(&chain->buffers)) {
+        timer_mod(chain->drain_timer,
+              qemu_clock_get_ns(QEMU_CLOCK_HOST) + chain->n->rsc_timeout);
+    }
+}
+
+static void virtio_net_rsc_cleanup(VirtIONet *n)
+{
+    VirtioNetRscChain *chain, *rn_chain;
+    VirtioNetRscSeg *seg, *rn_seg;
+
+    QTAILQ_FOREACH_SAFE(chain, &n->rsc_chains, next, rn_chain) {
+        QTAILQ_FOREACH_SAFE(seg, &chain->buffers, next, rn_seg) {
+            QTAILQ_REMOVE(&chain->buffers, seg, next);
+            g_free(seg->buf);
+            g_free(seg);
+        }
+
+        timer_free(chain->drain_timer);
+        QTAILQ_REMOVE(&n->rsc_chains, chain, next);
+        g_free(chain);
+    }
+}
+
+static void virtio_net_rsc_cache_buf(VirtioNetRscChain *chain,
+                                     NetClientState *nc,
+                                     const uint8_t *buf, size_t size)
+{
+    uint16_t hdr_len;
+    VirtioNetRscSeg *seg;
+
+    hdr_len = chain->n->guest_hdr_len;
+    seg = g_new(VirtioNetRscSeg, 1);
+    seg->buf = g_malloc(hdr_len + sizeof(struct eth_header)
+        + sizeof(struct ip6_header) + VIRTIO_NET_MAX_TCP_PAYLOAD);
+    memcpy(seg->buf, buf, size);
+    seg->size = size;
+    seg->packets = 1;
+    seg->dup_ack = 0;
+    seg->is_coalesced = 0;
+    seg->nc = nc;
+
+    QTAILQ_INSERT_TAIL(&chain->buffers, seg, next);
+    chain->stat.cache++;
+
+    switch (chain->proto) {
+    case ETH_P_IP:
+        virtio_net_rsc_extract_unit4(chain, seg->buf, &seg->unit);
+        break;
+    case ETH_P_IPV6:
+        virtio_net_rsc_extract_unit6(chain, seg->buf, &seg->unit);
+        break;
+    default:
+        g_assert_not_reached();
+    }
+}
+
+static int32_t virtio_net_rsc_handle_ack(VirtioNetRscChain *chain,
+                                         VirtioNetRscSeg *seg,
+                                         const uint8_t *buf,
+                                         struct tcp_header *n_tcp,
+                                         struct tcp_header *o_tcp)
+{
+    uint32_t nack, oack;
+    uint16_t nwin, owin;
+
+    nack = htonl(n_tcp->th_ack);
+    nwin = htons(n_tcp->th_win);
+    oack = htonl(o_tcp->th_ack);
+    owin = htons(o_tcp->th_win);
+
+    if ((nack - oack) >= VIRTIO_NET_MAX_TCP_PAYLOAD) {
+        chain->stat.ack_out_of_win++;
+        return RSC_FINAL;
+    } else if (nack == oack) {
+        /* duplicated ack or window probe */
+        if (nwin == owin) {
+            /* duplicated ack, add dup ack count due to whql test up to 1 */
+            chain->stat.dup_ack++;
+            return RSC_FINAL;
+        } else {
+            /* Coalesce window update */
+            o_tcp->th_win = n_tcp->th_win;
+            chain->stat.win_update++;
+            return RSC_COALESCE;
+        }
+    } else {
+        /* pure ack, go to 'C', finalize*/
+        chain->stat.pure_ack++;
+        return RSC_FINAL;
+    }
+}
+
+static int32_t virtio_net_rsc_coalesce_data(VirtioNetRscChain *chain,
+                                            VirtioNetRscSeg *seg,
+                                            const uint8_t *buf,
+                                            VirtioNetRscUnit *n_unit)
+{
+    void *data;
+    uint16_t o_ip_len;
+    uint32_t nseq, oseq;
+    VirtioNetRscUnit *o_unit;
+
+    o_unit = &seg->unit;
+    o_ip_len = htons(*o_unit->ip_plen);
+    nseq = htonl(n_unit->tcp->th_seq);
+    oseq = htonl(o_unit->tcp->th_seq);
+
+    /* out of order or retransmitted. */
+    if ((nseq - oseq) > VIRTIO_NET_MAX_TCP_PAYLOAD) {
+        chain->stat.data_out_of_win++;
+        return RSC_FINAL;
+    }
+
+    data = ((uint8_t *)n_unit->tcp) + n_unit->tcp_hdrlen;
+    if (nseq == oseq) {
+        if ((o_unit->payload == 0) && n_unit->payload) {
+            /* From no payload to payload, normal case, not a dup ack or etc */
+            chain->stat.data_after_pure_ack++;
+            goto coalesce;
+        } else {
+            return virtio_net_rsc_handle_ack(chain, seg, buf,
+                                             n_unit->tcp, o_unit->tcp);
+        }
+    } else if ((nseq - oseq) != o_unit->payload) {
+        /* Not a consistent packet, out of order */
+        chain->stat.data_out_of_order++;
+        return RSC_FINAL;
+    } else {
+coalesce:
+        if ((o_ip_len + n_unit->payload) > chain->max_payload) {
+            chain->stat.over_size++;
+            return RSC_FINAL;
+        }
+
+        /* Here comes the right data, the payload length in v4/v6 is different,
+           so use the field value to update and record the new data len */
+        o_unit->payload += n_unit->payload; /* update new data len */
+
+        /* update field in ip header */
+        *o_unit->ip_plen = htons(o_ip_len + n_unit->payload);
+
+        /* Bring 'PUSH' big, the whql test guide says 'PUSH' can be coalesced
+           for windows guest, while this may change the behavior for linux
+           guest (only if it uses RSC feature). */
+        o_unit->tcp->th_offset_flags = n_unit->tcp->th_offset_flags;
+
+        o_unit->tcp->th_ack = n_unit->tcp->th_ack;
+        o_unit->tcp->th_win = n_unit->tcp->th_win;
+
+        memmove(seg->buf + seg->size, data, n_unit->payload);
+        seg->size += n_unit->payload;
+        seg->packets++;
+        chain->stat.coalesced++;
+        return RSC_COALESCE;
+    }
+}
+
+static int32_t virtio_net_rsc_coalesce4(VirtioNetRscChain *chain,
+                                        VirtioNetRscSeg *seg,
+                                        const uint8_t *buf, size_t size,
+                                        VirtioNetRscUnit *unit)
+{
+    struct ip_header *ip1, *ip2;
+
+    ip1 = (struct ip_header *)(unit->ip);
+    ip2 = (struct ip_header *)(seg->unit.ip);
+    if ((ip1->ip_src ^ ip2->ip_src) || (ip1->ip_dst ^ ip2->ip_dst)
+        || (unit->tcp->th_sport ^ seg->unit.tcp->th_sport)
+        || (unit->tcp->th_dport ^ seg->unit.tcp->th_dport)) {
+        chain->stat.no_match++;
+        return RSC_NO_MATCH;
+    }
+
+    return virtio_net_rsc_coalesce_data(chain, seg, buf, unit);
+}
+
+static int32_t virtio_net_rsc_coalesce6(VirtioNetRscChain *chain,
+                                        VirtioNetRscSeg *seg,
+                                        const uint8_t *buf, size_t size,
+                                        VirtioNetRscUnit *unit)
+{
+    struct ip6_header *ip1, *ip2;
+
+    ip1 = (struct ip6_header *)(unit->ip);
+    ip2 = (struct ip6_header *)(seg->unit.ip);
+    if (memcmp(&ip1->ip6_src, &ip2->ip6_src, sizeof(struct in6_address))
+        || memcmp(&ip1->ip6_dst, &ip2->ip6_dst, sizeof(struct in6_address))
+        || (unit->tcp->th_sport ^ seg->unit.tcp->th_sport)
+        || (unit->tcp->th_dport ^ seg->unit.tcp->th_dport)) {
+            chain->stat.no_match++;
+            return RSC_NO_MATCH;
+    }
+
+    return virtio_net_rsc_coalesce_data(chain, seg, buf, unit);
+}
+
+/* Packets with 'SYN' should bypass, other flag should be sent after drain
+ * to prevent out of order */
+static int virtio_net_rsc_tcp_ctrl_check(VirtioNetRscChain *chain,
+                                         struct tcp_header *tcp)
+{
+    uint16_t tcp_hdr;
+    uint16_t tcp_flag;
+
+    tcp_flag = htons(tcp->th_offset_flags);
+    tcp_hdr = (tcp_flag & VIRTIO_NET_TCP_HDR_LENGTH) >> 10;
+    tcp_flag &= VIRTIO_NET_TCP_FLAG;
+    if (tcp_flag & TH_SYN) {
+        chain->stat.tcp_syn++;
+        return RSC_BYPASS;
+    }
+
+    if (tcp_flag & (TH_FIN | TH_URG | TH_RST | TH_ECE | TH_CWR)) {
+        chain->stat.tcp_ctrl_drain++;
+        return RSC_FINAL;
+    }
+
+    if (tcp_hdr > sizeof(struct tcp_header)) {
+        chain->stat.tcp_all_opt++;
+        return RSC_FINAL;
+    }
+
+    return RSC_CANDIDATE;
+}
+
+static size_t virtio_net_rsc_do_coalesce(VirtioNetRscChain *chain,
+                                         NetClientState *nc,
+                                         const uint8_t *buf, size_t size,
+                                         VirtioNetRscUnit *unit)
+{
+    int ret;
+    VirtioNetRscSeg *seg, *nseg;
+
+    if (QTAILQ_EMPTY(&chain->buffers)) {
+        chain->stat.empty_cache++;
+        virtio_net_rsc_cache_buf(chain, nc, buf, size);
+        timer_mod(chain->drain_timer,
+              qemu_clock_get_ns(QEMU_CLOCK_HOST) + chain->n->rsc_timeout);
+        return size;
+    }
+
+    QTAILQ_FOREACH_SAFE(seg, &chain->buffers, next, nseg) {
+        if (chain->proto == ETH_P_IP) {
+            ret = virtio_net_rsc_coalesce4(chain, seg, buf, size, unit);
+        } else {
+            ret = virtio_net_rsc_coalesce6(chain, seg, buf, size, unit);
+        }
+
+        if (ret == RSC_FINAL) {
+            if (virtio_net_rsc_drain_seg(chain, seg) == 0) {
+                /* Send failed */
+                chain->stat.final_failed++;
+                return 0;
+            }
+
+            /* Send current packet */
+            return virtio_net_do_receive(nc, buf, size);
+        } else if (ret == RSC_NO_MATCH) {
+            continue;
+        } else {
+            /* Coalesced, mark coalesced flag to tell calc cksum for ipv4 */
+            seg->is_coalesced = 1;
+            return size;
+        }
+    }
+
+    chain->stat.no_match_cache++;
+    virtio_net_rsc_cache_buf(chain, nc, buf, size);
+    return size;
+}
+
+/* Drain a connection data, this is to avoid out of order segments */
+static size_t virtio_net_rsc_drain_flow(VirtioNetRscChain *chain,
+                                        NetClientState *nc,
+                                        const uint8_t *buf, size_t size,
+                                        uint16_t ip_start, uint16_t ip_size,
+                                        uint16_t tcp_port)
+{
+    VirtioNetRscSeg *seg, *nseg;
+    uint32_t ppair1, ppair2;
+
+    ppair1 = *(uint32_t *)(buf + tcp_port);
+    QTAILQ_FOREACH_SAFE(seg, &chain->buffers, next, nseg) {
+        ppair2 = *(uint32_t *)(seg->buf + tcp_port);
+        if (memcmp(buf + ip_start, seg->buf + ip_start, ip_size)
+            || (ppair1 != ppair2)) {
+            continue;
+        }
+        if (virtio_net_rsc_drain_seg(chain, seg) == 0) {
+            chain->stat.drain_failed++;
+        }
+
+        break;
+    }
+
+    return virtio_net_do_receive(nc, buf, size);
+}
+
+static int32_t virtio_net_rsc_sanity_check4(VirtioNetRscChain *chain,
+                                            struct ip_header *ip,
+                                            const uint8_t *buf, size_t size)
+{
+    uint16_t ip_len;
+
+    /* Not an ipv4 packet */
+    if (((ip->ip_ver_len & 0xF0) >> 4) != IP_HEADER_VERSION_4) {
+        chain->stat.ip_option++;
+        return RSC_BYPASS;
+    }
+
+    /* Don't handle packets with ip option */
+    if ((ip->ip_ver_len & 0xF) != VIRTIO_NET_IP4_HEADER_LENGTH) {
+        chain->stat.ip_option++;
+        return RSC_BYPASS;
+    }
+
+    if (ip->ip_p != IPPROTO_TCP) {
+        chain->stat.bypass_not_tcp++;
+        return RSC_BYPASS;
+    }
+
+    /* Don't handle packets with ip fragment */
+    if (!(htons(ip->ip_off) & IP_DF)) {
+        chain->stat.ip_frag++;
+        return RSC_BYPASS;
+    }
+
+    /* Don't handle packets with ecn flag */
+    if (IPTOS_ECN(ip->ip_tos)) {
+        chain->stat.ip_ecn++;
+        return RSC_BYPASS;
+    }
+
+    ip_len = htons(ip->ip_len);
+    if (ip_len < (sizeof(struct ip_header) + sizeof(struct tcp_header))
+        || ip_len > (size - chain->n->guest_hdr_len -
+                     sizeof(struct eth_header))) {
+        chain->stat.ip_hacked++;
+        return RSC_BYPASS;
+    }
+
+    return RSC_CANDIDATE;
+}
+
+static size_t virtio_net_rsc_receive4(VirtioNetRscChain *chain,
+                                      NetClientState *nc,
+                                      const uint8_t *buf, size_t size)
+{
+    int32_t ret;
+    uint16_t hdr_len;
+    VirtioNetRscUnit unit;
+
+    hdr_len = ((VirtIONet *)(chain->n))->guest_hdr_len;
+
+    if (size < (hdr_len + sizeof(struct eth_header) + sizeof(struct ip_header)
+        + sizeof(struct tcp_header))) {
+        chain->stat.bypass_not_tcp++;
+        return virtio_net_do_receive(nc, buf, size);
+    }
+
+    virtio_net_rsc_extract_unit4(chain, buf, &unit);
+    if (virtio_net_rsc_sanity_check4(chain, unit.ip, buf, size)
+        != RSC_CANDIDATE) {
+        return virtio_net_do_receive(nc, buf, size);
+    }
+
+    ret = virtio_net_rsc_tcp_ctrl_check(chain, unit.tcp);
+    if (ret == RSC_BYPASS) {
+        return virtio_net_do_receive(nc, buf, size);
+    } else if (ret == RSC_FINAL) {
+        return virtio_net_rsc_drain_flow(chain, nc, buf, size,
+                ((hdr_len + sizeof(struct eth_header)) + 12),
+                VIRTIO_NET_IP4_ADDR_SIZE,
+                hdr_len + sizeof(struct eth_header) + sizeof(struct ip_header));
+    }
+
+    return virtio_net_rsc_do_coalesce(chain, nc, buf, size, &unit);
+}
+
+static int32_t virtio_net_rsc_sanity_check6(VirtioNetRscChain *chain,
+                                            struct ip6_header *ip6,
+                                            const uint8_t *buf, size_t size)
+{
+    uint16_t ip_len;
+
+    if (((ip6->ip6_ctlun.ip6_un1.ip6_un1_flow & 0xF0) >> 4)
+        != IP_HEADER_VERSION_6) {
+        return RSC_BYPASS;
+    }
+
+    /* Both option and protocol is checked in this */
+    if (ip6->ip6_ctlun.ip6_un1.ip6_un1_nxt != IPPROTO_TCP) {
+        chain->stat.bypass_not_tcp++;
+        return RSC_BYPASS;
+    }
+
+    ip_len = htons(ip6->ip6_ctlun.ip6_un1.ip6_un1_plen);
+    if (ip_len < sizeof(struct tcp_header) ||
+        ip_len > (size - chain->n->guest_hdr_len - sizeof(struct eth_header)
+                  - sizeof(struct ip6_header))) {
+        chain->stat.ip_hacked++;
+        return RSC_BYPASS;
+    }
+
+    /* Don't handle packets with ecn flag */
+    if (IP6_ECN(ip6->ip6_ctlun.ip6_un3.ip6_un3_ecn)) {
+        chain->stat.ip_ecn++;
+        return RSC_BYPASS;
+    }
+
+    return RSC_CANDIDATE;
+}
+
+static size_t virtio_net_rsc_receive6(void *opq, NetClientState *nc,
+                                      const uint8_t *buf, size_t size)
+{
+    int32_t ret;
+    uint16_t hdr_len;
+    VirtioNetRscChain *chain;
+    VirtioNetRscUnit unit;
+
+    chain = (VirtioNetRscChain *)opq;
+    hdr_len = ((VirtIONet *)(chain->n))->guest_hdr_len;
+
+    if (size < (hdr_len + sizeof(struct eth_header) + sizeof(struct ip6_header)
+        + sizeof(tcp_header))) {
+        return virtio_net_do_receive(nc, buf, size);
+    }
+
+    virtio_net_rsc_extract_unit6(chain, buf, &unit);
+    if (RSC_CANDIDATE != virtio_net_rsc_sanity_check6(chain,
+                                                 unit.ip, buf, size)) {
+        return virtio_net_do_receive(nc, buf, size);
+    }
+
+    ret = virtio_net_rsc_tcp_ctrl_check(chain, unit.tcp);
+    if (ret == RSC_BYPASS) {
+        return virtio_net_do_receive(nc, buf, size);
+    } else if (ret == RSC_FINAL) {
+        return virtio_net_rsc_drain_flow(chain, nc, buf, size,
+                ((hdr_len + sizeof(struct eth_header)) + 8),
+                VIRTIO_NET_IP6_ADDR_SIZE,
+                hdr_len + sizeof(struct eth_header)
+                + sizeof(struct ip6_header));
+    }
+
+    return virtio_net_rsc_do_coalesce(chain, nc, buf, size, &unit);
+}
+
+static VirtioNetRscChain *virtio_net_rsc_lookup_chain(VirtIONet *n,
+                                                      NetClientState *nc,
+                                                      uint16_t proto)
+{
+    VirtioNetRscChain *chain;
+
+    if ((proto != (uint16_t)ETH_P_IP) && (proto != (uint16_t)ETH_P_IPV6)) {
+        return NULL;
+    }
+
+    QTAILQ_FOREACH(chain, &n->rsc_chains, next) {
+        if (chain->proto == proto) {
+            return chain;
+        }
+    }
+
+    chain = g_malloc(sizeof(*chain));
+    chain->n = n;
+    chain->proto = proto;
+    if (proto == (uint16_t)ETH_P_IP) {
+        chain->max_payload = VIRTIO_NET_MAX_IP4_PAYLOAD;
+        chain->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
+    } else {
+        chain->max_payload = VIRTIO_NET_MAX_IP6_PAYLOAD;
+        chain->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
+    }
+    chain->drain_timer = timer_new_ns(QEMU_CLOCK_HOST,
+                                      virtio_net_rsc_purge, chain);
+    memset(&chain->stat, 0, sizeof(chain->stat));
+
+    QTAILQ_INIT(&chain->buffers);
+    QTAILQ_INSERT_TAIL(&n->rsc_chains, chain, next);
+
+    return chain;
+}
+
+static ssize_t virtio_net_rsc_receive(NetClientState *nc,
+                                      const uint8_t *buf,
+                                      size_t size)
+{
+    uint16_t proto;
+    VirtioNetRscChain *chain;
+    struct eth_header *eth;
+    VirtIONet *n;
+
+    n = qemu_get_nic_opaque(nc);
+    if (size < (n->host_hdr_len + sizeof(struct eth_header))) {
+        return virtio_net_do_receive(nc, buf, size);
+    }
+
+    eth = (struct eth_header *)(buf + n->guest_hdr_len);
+    proto = htons(eth->h_proto);
+
+    chain = virtio_net_rsc_lookup_chain(n, nc, proto);
+    if (chain) {
+        chain->stat.received++;
+        if (proto == (uint16_t)ETH_P_IP && n->rsc4_enabled) {
+            return virtio_net_rsc_receive4(chain, nc, buf, size);
+        } else if (proto == (uint16_t)ETH_P_IPV6 && n->rsc6_enabled) {
+            return virtio_net_rsc_receive6(chain, nc, buf, size);
+        }
+    }
+    return virtio_net_do_receive(nc, buf, size);
+}
+
+static ssize_t virtio_net_receive(NetClientState *nc, const uint8_t *buf,
+                                  size_t size)
+{
+    VirtIONet *n = qemu_get_nic_opaque(nc);
+    if ((n->rsc4_enabled || n->rsc6_enabled)) {
+        return virtio_net_rsc_receive(nc, buf, size);
+    } else {
+        return virtio_net_do_receive(nc, buf, size);
+    }
+}
+
+static int32_t virtio_net_flush_tx(VirtIONetQueue *q);
+
+static void virtio_net_tx_complete(NetClientState *nc, ssize_t len)
+{
+    VirtIONet *n = qemu_get_nic_opaque(nc);
+    VirtIONetQueue *q = virtio_net_get_subqueue(nc);
+    VirtIODevice *vdev = VIRTIO_DEVICE(n);
+    int ret;
+
+    virtqueue_push(q->tx_vq, q->async_tx.elem, 0);
+    virtio_notify(vdev, q->tx_vq);
+
+    g_free(q->async_tx.elem);
+    q->async_tx.elem = NULL;
+
+    virtio_queue_set_notification(q->tx_vq, 1);
+    ret = virtio_net_flush_tx(q);
+    if (ret >= n->tx_burst) {
+        /*
+         * the flush has been stopped by tx_burst
+         * we will not receive notification for the
+         * remainining part, so re-schedule
+         */
+        virtio_queue_set_notification(q->tx_vq, 0);
+        if (q->tx_bh) {
+            qemu_bh_schedule(q->tx_bh);
+        } else {
+            timer_mod(q->tx_timer,
+                      qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + n->tx_timeout);
+        }
+        q->tx_waiting = 1;
+    }
+}
+
+/* TX */
+static int32_t virtio_net_flush_tx(VirtIONetQueue *q)
+{
+    VirtIONet *n = q->n;
+    VirtIODevice *vdev = VIRTIO_DEVICE(n);
+    VirtQueueElement *elem;
+    int32_t num_packets = 0;
+    int queue_index = vq2q(virtio_get_queue_index(q->tx_vq));
+    if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) {
+        return num_packets;
+    }
+
+    if (q->async_tx.elem) {
+        virtio_queue_set_notification(q->tx_vq, 0);
+        return num_packets;
+    }
+
+    for (;;) {
+        ssize_t ret;
+        unsigned int out_num;
+        struct iovec sg[VIRTQUEUE_MAX_SIZE], sg2[VIRTQUEUE_MAX_SIZE + 1], *out_sg;
+        struct virtio_net_hdr_mrg_rxbuf mhdr;
+
+        elem = virtqueue_pop(q->tx_vq, sizeof(VirtQueueElement));
+        if (!elem) {
+            break;
+        }
+
+        out_num = elem->out_num;
+        out_sg = elem->out_sg;
+        if (out_num < 1) {
+            virtio_error(vdev, "virtio-net header not in first element");
+            virtqueue_detach_element(q->tx_vq, elem, 0);
+            g_free(elem);
+            return -EINVAL;
+        }
+
+        if (n->has_vnet_hdr) {
+            if (iov_to_buf(out_sg, out_num, 0, &mhdr, n->guest_hdr_len) <
+                n->guest_hdr_len) {
+                virtio_error(vdev, "virtio-net header incorrect");
+                virtqueue_detach_element(q->tx_vq, elem, 0);
+                g_free(elem);
+                return -EINVAL;
+            }
+            if (n->needs_vnet_hdr_swap) {
+                virtio_net_hdr_swap(vdev, (void *) &mhdr);
+                sg2[0].iov_base = &mhdr;
+                sg2[0].iov_len = n->guest_hdr_len;
+                out_num = iov_copy(&sg2[1], ARRAY_SIZE(sg2) - 1,
+                                   out_sg, out_num,
+                                   n->guest_hdr_len, -1);
+                if (out_num == VIRTQUEUE_MAX_SIZE) {
+                    goto drop;
+                }
+                out_num += 1;
+                out_sg = sg2;
+            }
+        }
+        /*
+         * If host wants to see the guest header as is, we can
+         * pass it on unchanged. Otherwise, copy just the parts
+         * that host is interested in.
+         */
+        assert(n->host_hdr_len <= n->guest_hdr_len);
+        if (n->host_hdr_len != n->guest_hdr_len) {
+            unsigned sg_num = iov_copy(sg, ARRAY_SIZE(sg),
+                                       out_sg, out_num,
+                                       0, n->host_hdr_len);
+            sg_num += iov_copy(sg + sg_num, ARRAY_SIZE(sg) - sg_num,
+                             out_sg, out_num,
+                             n->guest_hdr_len, -1);
+            out_num = sg_num;
+            out_sg = sg;
+        }
+
+        ret = qemu_sendv_packet_async(qemu_get_subqueue(n->nic, queue_index),
+                                      out_sg, out_num, virtio_net_tx_complete);
+        if (ret == 0) {
+            virtio_queue_set_notification(q->tx_vq, 0);
+            q->async_tx.elem = elem;
+            return -EBUSY;
+        }
+
+drop:
+        virtqueue_push(q->tx_vq, elem, 0);
+        virtio_notify(vdev, q->tx_vq);
+        g_free(elem);
+
+        if (++num_packets >= n->tx_burst) {
+            break;
+        }
+    }
+    return num_packets;
+}
+
+static void virtio_net_tx_timer(void *opaque);
+
+static void virtio_net_handle_tx_timer(VirtIODevice *vdev, VirtQueue *vq)
+{
+    VirtIONet *n = VIRTIO_NET(vdev);
+    VirtIONetQueue *q = &n->vqs[vq2q(virtio_get_queue_index(vq))];
+
+    if (unlikely((n->status & VIRTIO_NET_S_LINK_UP) == 0)) {
+        virtio_net_drop_tx_queue_data(vdev, vq);
+        return;
+    }
+
+    /* This happens when device was stopped but VCPU wasn't. */
+    if (!vdev->vm_running) {
+        q->tx_waiting = 1;
+        return;
+    }
+
+    if (q->tx_waiting) {
+        /* We already have queued packets, immediately flush */
+        timer_del(q->tx_timer);
+        virtio_net_tx_timer(q);
+    } else {
+        /* re-arm timer to flush it (and more) on next tick */
+        timer_mod(q->tx_timer,
+                  qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + n->tx_timeout);
+        q->tx_waiting = 1;
+        virtio_queue_set_notification(vq, 0);
+    }
+}
+
+static void virtio_net_handle_tx_bh(VirtIODevice *vdev, VirtQueue *vq)
+{
+    VirtIONet *n = VIRTIO_NET(vdev);
+    VirtIONetQueue *q = &n->vqs[vq2q(virtio_get_queue_index(vq))];
+
+    if (unlikely((n->status & VIRTIO_NET_S_LINK_UP) == 0)) {
+        virtio_net_drop_tx_queue_data(vdev, vq);
+        return;
+    }
+
+    if (unlikely(q->tx_waiting)) {
+        return;
+    }
+    q->tx_waiting = 1;
+    /* This happens when device was stopped but VCPU wasn't. */
+    if (!vdev->vm_running) {
+        return;
+    }
+    virtio_queue_set_notification(vq, 0);
+    qemu_bh_schedule(q->tx_bh);
+}
+
+static void virtio_net_tx_timer(void *opaque)
+{
+    VirtIONetQueue *q = opaque;
+    VirtIONet *n = q->n;
+    VirtIODevice *vdev = VIRTIO_DEVICE(n);
+    int ret;
+
+    /* This happens when device was stopped but BH wasn't. */
+    if (!vdev->vm_running) {
+        /* Make sure tx waiting is set, so we'll run when restarted. */
+        assert(q->tx_waiting);
+        return;
+    }
+
+    q->tx_waiting = 0;
+
+    /* Just in case the driver is not ready on more */
+    if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) {
+        return;
+    }
+
+    ret = virtio_net_flush_tx(q);
+    if (ret == -EBUSY || ret == -EINVAL) {
+        return;
+    }
+    /*
+     * If we flush a full burst of packets, assume there are
+     * more coming and immediately rearm
+     */
+    if (ret >= n->tx_burst) {
+        q->tx_waiting = 1;
+        timer_mod(q->tx_timer,
+                  qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + n->tx_timeout);
+        return;
+    }
+    /*
+     * If less than a full burst, re-enable notification and flush
+     * anything that may have come in while we weren't looking.  If
+     * we find something, assume the guest is still active and rearm
+     */
+    virtio_queue_set_notification(q->tx_vq, 1);
+    ret = virtio_net_flush_tx(q);
+    if (ret > 0) {
+        virtio_queue_set_notification(q->tx_vq, 0);
+        q->tx_waiting = 1;
+        timer_mod(q->tx_timer,
+                  qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + n->tx_timeout);
+    }
+}
+
+static void virtio_net_tx_bh(void *opaque)
+{
+    VirtIONetQueue *q = opaque;
+    VirtIONet *n = q->n;
+    VirtIODevice *vdev = VIRTIO_DEVICE(n);
+    int32_t ret;
+
+    /* This happens when device was stopped but BH wasn't. */
+    if (!vdev->vm_running) {
+        /* Make sure tx waiting is set, so we'll run when restarted. */
+        assert(q->tx_waiting);
+        return;
+    }
+
+    q->tx_waiting = 0;
+
+    /* Just in case the driver is not ready on more */
+    if (unlikely(!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK))) {
+        return;
+    }
+
+    ret = virtio_net_flush_tx(q);
+    if (ret == -EBUSY || ret == -EINVAL) {
+        return; /* Notification re-enable handled by tx_complete or device
+                 * broken */
+    }
+
+    /* If we flush a full burst of packets, assume there are
+     * more coming and immediately reschedule */
+    if (ret >= n->tx_burst) {
+        qemu_bh_schedule(q->tx_bh);
+        q->tx_waiting = 1;
+        return;
+    }
+
+    /* If less than a full burst, re-enable notification and flush
+     * anything that may have come in while we weren't looking.  If
+     * we find something, assume the guest is still active and reschedule */
+    virtio_queue_set_notification(q->tx_vq, 1);
+    ret = virtio_net_flush_tx(q);
+    if (ret == -EINVAL) {
+        return;
+    } else if (ret > 0) {
+        virtio_queue_set_notification(q->tx_vq, 0);
+        qemu_bh_schedule(q->tx_bh);
+        q->tx_waiting = 1;
+    }
+}
+
+static void virtio_net_add_queue(VirtIONet *n, int index)
+{
+    VirtIODevice *vdev = VIRTIO_DEVICE(n);
+
+    n->vqs[index].rx_vq = virtio_add_queue(vdev, n->net_conf.rx_queue_size,
+                                           virtio_net_handle_rx);
+
+    if (n->net_conf.tx && !strcmp(n->net_conf.tx, "timer")) {
+        n->vqs[index].tx_vq =
+            virtio_add_queue(vdev, n->net_conf.tx_queue_size,
+                             virtio_net_handle_tx_timer);
+        n->vqs[index].tx_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
+                                              virtio_net_tx_timer,
+                                              &n->vqs[index]);
+    } else {
+        n->vqs[index].tx_vq =
+            virtio_add_queue(vdev, n->net_conf.tx_queue_size,
+                             virtio_net_handle_tx_bh);
+        n->vqs[index].tx_bh = qemu_bh_new(virtio_net_tx_bh, &n->vqs[index]);
+    }
+
+    n->vqs[index].tx_waiting = 0;
+    n->vqs[index].n = n;
+}
+
+static void virtio_net_del_queue(VirtIONet *n, int index)
+{
+    VirtIODevice *vdev = VIRTIO_DEVICE(n);
+    VirtIONetQueue *q = &n->vqs[index];
+    NetClientState *nc = qemu_get_subqueue(n->nic, index);
+
+    qemu_purge_queued_packets(nc);
+
+    virtio_del_queue(vdev, index * 2);
+    if (q->tx_timer) {
+        timer_free(q->tx_timer);
+        q->tx_timer = NULL;
+    } else {
+        qemu_bh_delete(q->tx_bh);
+        q->tx_bh = NULL;
+    }
+    q->tx_waiting = 0;
+    virtio_del_queue(vdev, index * 2 + 1);
+}
+
+static void virtio_net_change_num_queue_pairs(VirtIONet *n, int new_max_queue_pairs)
+{
+    VirtIODevice *vdev = VIRTIO_DEVICE(n);
+    int old_num_queues = virtio_get_num_queues(vdev);
+    int new_num_queues = new_max_queue_pairs * 2 + 1;
+    int i;
+
+    assert(old_num_queues >= 3);
+    assert(old_num_queues % 2 == 1);
+
+    if (old_num_queues == new_num_queues) {
+        return;
+    }
+
+    /*
+     * We always need to remove and add ctrl vq if
+     * old_num_queues != new_num_queues. Remove ctrl_vq first,
+     * and then we only enter one of the following two loops.
+     */
+    virtio_del_queue(vdev, old_num_queues - 1);
+
+    for (i = new_num_queues - 1; i < old_num_queues - 1; i += 2) {
+        /* new_num_queues < old_num_queues */
+        virtio_net_del_queue(n, i / 2);
+    }
+
+    for (i = old_num_queues - 1; i < new_num_queues - 1; i += 2) {
+        /* new_num_queues > old_num_queues */
+        virtio_net_add_queue(n, i / 2);
+    }
+
+    /* add ctrl_vq last */
+    n->ctrl_vq = virtio_add_queue(vdev, 64, virtio_net_handle_ctrl);
+}
+
+static void virtio_net_set_multiqueue(VirtIONet *n, int multiqueue)
+{
+    int max = multiqueue ? n->max_queue_pairs : 1;
+
+    n->multiqueue = multiqueue;
+    virtio_net_change_num_queue_pairs(n, max);
+
+    virtio_net_set_queue_pairs(n);
+}
+
+static int virtio_net_post_load_device(void *opaque, int version_id)
+{
+    VirtIONet *n = opaque;
+    VirtIODevice *vdev = VIRTIO_DEVICE(n);
+    int i, link_down;
+
+    trace_virtio_net_post_load_device();
+    virtio_net_set_mrg_rx_bufs(n, n->mergeable_rx_bufs,
+                               virtio_vdev_has_feature(vdev,
+                                                       VIRTIO_F_VERSION_1),
+                               virtio_vdev_has_feature(vdev,
+                                                       VIRTIO_NET_F_HASH_REPORT));
+
+    /* MAC_TABLE_ENTRIES may be different from the saved image */
+    if (n->mac_table.in_use > MAC_TABLE_ENTRIES) {
+        n->mac_table.in_use = 0;
+    }
+
+    if (!virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS)) {
+        n->curr_guest_offloads = virtio_net_supported_guest_offloads(n);
+    }
+
+    /*
+     * curr_guest_offloads will be later overwritten by the
+     * virtio_set_features_nocheck call done from the virtio_load.
+     * Here we make sure it is preserved and restored accordingly
+     * in the virtio_net_post_load_virtio callback.
+     */
+    n->saved_guest_offloads = n->curr_guest_offloads;
+
+    virtio_net_set_queue_pairs(n);
+
+    /* Find the first multicast entry in the saved MAC filter */
+    for (i = 0; i < n->mac_table.in_use; i++) {
+        if (n->mac_table.macs[i * ETH_ALEN] & 1) {
+            break;
+        }
+    }
+    n->mac_table.first_multi = i;
+
+    /* nc.link_down can't be migrated, so infer link_down according
+     * to link status bit in n->status */
+    link_down = (n->status & VIRTIO_NET_S_LINK_UP) == 0;
+    for (i = 0; i < n->max_queue_pairs; i++) {
+        qemu_get_subqueue(n->nic, i)->link_down = link_down;
+    }
+
+    if (virtio_vdev_has_feature(vdev, VIRTIO_NET_F_GUEST_ANNOUNCE) &&
+        virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ)) {
+        qemu_announce_timer_reset(&n->announce_timer, migrate_announce_params(),
+                                  QEMU_CLOCK_VIRTUAL,
+                                  virtio_net_announce_timer, n);
+        if (n->announce_timer.round) {
+            timer_mod(n->announce_timer.tm,
+                      qemu_clock_get_ms(n->announce_timer.type));
+        } else {
+            qemu_announce_timer_del(&n->announce_timer, false);
+        }
+    }
+
+    if (n->rss_data.enabled) {
+        n->rss_data.enabled_software_rss = n->rss_data.populate_hash;
+        if (!n->rss_data.populate_hash) {
+            if (!virtio_net_attach_epbf_rss(n)) {
+                if (get_vhost_net(qemu_get_queue(n->nic)->peer)) {
+                    warn_report("Can't post-load eBPF RSS for vhost");
+                } else {
+                    warn_report("Can't post-load eBPF RSS - "
+                                "fallback to software RSS");
+                    n->rss_data.enabled_software_rss = true;
+                }
+            }
+        }
+
+        trace_virtio_net_rss_enable(n->rss_data.hash_types,
+                                    n->rss_data.indirections_len,
+                                    sizeof(n->rss_data.key));
+    } else {
+        trace_virtio_net_rss_disable();
+    }
+    return 0;
+}
+
+static int virtio_net_post_load_virtio(VirtIODevice *vdev)
+{
+    VirtIONet *n = VIRTIO_NET(vdev);
+    /*
+     * The actual needed state is now in saved_guest_offloads,
+     * see virtio_net_post_load_device for detail.
+     * Restore it back and apply the desired offloads.
+     */
+    n->curr_guest_offloads = n->saved_guest_offloads;
+    if (peer_has_vnet_hdr(n)) {
+        virtio_net_apply_guest_offloads(n);
+    }
+
+    return 0;
+}
+
+/* tx_waiting field of a VirtIONetQueue */
+static const VMStateDescription vmstate_virtio_net_queue_tx_waiting = {
+    .name = "virtio-net-queue-tx_waiting",
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT32(tx_waiting, VirtIONetQueue),
+        VMSTATE_END_OF_LIST()
+   },
+};
+
+static bool max_queue_pairs_gt_1(void *opaque, int version_id)
+{
+    return VIRTIO_NET(opaque)->max_queue_pairs > 1;
+}
+
+static bool has_ctrl_guest_offloads(void *opaque, int version_id)
+{
+    return virtio_vdev_has_feature(VIRTIO_DEVICE(opaque),
+                                   VIRTIO_NET_F_CTRL_GUEST_OFFLOADS);
+}
+
+static bool mac_table_fits(void *opaque, int version_id)
+{
+    return VIRTIO_NET(opaque)->mac_table.in_use <= MAC_TABLE_ENTRIES;
+}
+
+static bool mac_table_doesnt_fit(void *opaque, int version_id)
+{
+    return !mac_table_fits(opaque, version_id);
+}
+
+/* This temporary type is shared by all the WITH_TMP methods
+ * although only some fields are used by each.
+ */
+struct VirtIONetMigTmp {
+    VirtIONet      *parent;
+    VirtIONetQueue *vqs_1;
+    uint16_t        curr_queue_pairs_1;
+    uint8_t         has_ufo;
+    uint32_t        has_vnet_hdr;
+};
+
+/* The 2nd and subsequent tx_waiting flags are loaded later than
+ * the 1st entry in the queue_pairs and only if there's more than one
+ * entry.  We use the tmp mechanism to calculate a temporary
+ * pointer and count and also validate the count.
+ */
+
+static int virtio_net_tx_waiting_pre_save(void *opaque)
+{
+    struct VirtIONetMigTmp *tmp = opaque;
+
+    tmp->vqs_1 = tmp->parent->vqs + 1;
+    tmp->curr_queue_pairs_1 = tmp->parent->curr_queue_pairs - 1;
+    if (tmp->parent->curr_queue_pairs == 0) {
+        tmp->curr_queue_pairs_1 = 0;
+    }
+
+    return 0;
+}
+
+static int virtio_net_tx_waiting_pre_load(void *opaque)
+{
+    struct VirtIONetMigTmp *tmp = opaque;
+
+    /* Reuse the pointer setup from save */
+    virtio_net_tx_waiting_pre_save(opaque);
+
+    if (tmp->parent->curr_queue_pairs > tmp->parent->max_queue_pairs) {
+        error_report("virtio-net: curr_queue_pairs %x > max_queue_pairs %x",
+            tmp->parent->curr_queue_pairs, tmp->parent->max_queue_pairs);
+
+        return -EINVAL;
+    }
+
+    return 0; /* all good */
+}
+
+static const VMStateDescription vmstate_virtio_net_tx_waiting = {
+    .name      = "virtio-net-tx_waiting",
+    .pre_load  = virtio_net_tx_waiting_pre_load,
+    .pre_save  = virtio_net_tx_waiting_pre_save,
+    .fields    = (VMStateField[]) {
+        VMSTATE_STRUCT_VARRAY_POINTER_UINT16(vqs_1, struct VirtIONetMigTmp,
+                                     curr_queue_pairs_1,
+                                     vmstate_virtio_net_queue_tx_waiting,
+                                     struct VirtIONetQueue),
+        VMSTATE_END_OF_LIST()
+    },
+};
+
+/* the 'has_ufo' flag is just tested; if the incoming stream has the
+ * flag set we need to check that we have it
+ */
+static int virtio_net_ufo_post_load(void *opaque, int version_id)
+{
+    struct VirtIONetMigTmp *tmp = opaque;
+
+    if (tmp->has_ufo && !peer_has_ufo(tmp->parent)) {
+        error_report("virtio-net: saved image requires TUN_F_UFO support");
+        return -EINVAL;
+    }
+
+    return 0;
+}
+
+static int virtio_net_ufo_pre_save(void *opaque)
+{
+    struct VirtIONetMigTmp *tmp = opaque;
+
+    tmp->has_ufo = tmp->parent->has_ufo;
+
+    return 0;
+}
+
+static const VMStateDescription vmstate_virtio_net_has_ufo = {
+    .name      = "virtio-net-ufo",
+    .post_load = virtio_net_ufo_post_load,
+    .pre_save  = virtio_net_ufo_pre_save,
+    .fields    = (VMStateField[]) {
+        VMSTATE_UINT8(has_ufo, struct VirtIONetMigTmp),
+        VMSTATE_END_OF_LIST()
+    },
+};
+
+/* the 'has_vnet_hdr' flag is just tested; if the incoming stream has the
+ * flag set we need to check that we have it
+ */
+static int virtio_net_vnet_post_load(void *opaque, int version_id)
+{
+    struct VirtIONetMigTmp *tmp = opaque;
+
+    if (tmp->has_vnet_hdr && !peer_has_vnet_hdr(tmp->parent)) {
+        error_report("virtio-net: saved image requires vnet_hdr=on");
+        return -EINVAL;
+    }
+
+    return 0;
+}
+
+static int virtio_net_vnet_pre_save(void *opaque)
+{
+    struct VirtIONetMigTmp *tmp = opaque;
+
+    tmp->has_vnet_hdr = tmp->parent->has_vnet_hdr;
+
+    return 0;
+}
+
+static const VMStateDescription vmstate_virtio_net_has_vnet = {
+    .name      = "virtio-net-vnet",
+    .post_load = virtio_net_vnet_post_load,
+    .pre_save  = virtio_net_vnet_pre_save,
+    .fields    = (VMStateField[]) {
+        VMSTATE_UINT32(has_vnet_hdr, struct VirtIONetMigTmp),
+        VMSTATE_END_OF_LIST()
+    },
+};
+
+static bool virtio_net_rss_needed(void *opaque)
+{
+    return VIRTIO_NET(opaque)->rss_data.enabled;
+}
+
+static const VMStateDescription vmstate_virtio_net_rss = {
+    .name      = "virtio-net-device/rss",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .needed = virtio_net_rss_needed,
+    .fields = (VMStateField[]) {
+        VMSTATE_BOOL(rss_data.enabled, VirtIONet),
+        VMSTATE_BOOL(rss_data.redirect, VirtIONet),
+        VMSTATE_BOOL(rss_data.populate_hash, VirtIONet),
+        VMSTATE_UINT32(rss_data.hash_types, VirtIONet),
+        VMSTATE_UINT16(rss_data.indirections_len, VirtIONet),
+        VMSTATE_UINT16(rss_data.default_queue, VirtIONet),
+        VMSTATE_UINT8_ARRAY(rss_data.key, VirtIONet,
+                            VIRTIO_NET_RSS_MAX_KEY_SIZE),
+        VMSTATE_VARRAY_UINT16_ALLOC(rss_data.indirections_table, VirtIONet,
+                                    rss_data.indirections_len, 0,
+                                    vmstate_info_uint16, uint16_t),
+        VMSTATE_END_OF_LIST()
+    },
+};
+
+static const VMStateDescription vmstate_virtio_net_device = {
+    .name = "virtio-net-device",
+    .version_id = VIRTIO_NET_VM_VERSION,
+    .minimum_version_id = VIRTIO_NET_VM_VERSION,
+    .post_load = virtio_net_post_load_device,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT8_ARRAY(mac, VirtIONet, ETH_ALEN),
+        VMSTATE_STRUCT_POINTER(vqs, VirtIONet,
+                               vmstate_virtio_net_queue_tx_waiting,
+                               VirtIONetQueue),
+        VMSTATE_UINT32(mergeable_rx_bufs, VirtIONet),
+        VMSTATE_UINT16(status, VirtIONet),
+        VMSTATE_UINT8(promisc, VirtIONet),
+        VMSTATE_UINT8(allmulti, VirtIONet),
+        VMSTATE_UINT32(mac_table.in_use, VirtIONet),
+
+        /* Guarded pair: If it fits we load it, else we throw it away
+         * - can happen if source has a larger MAC table.; post-load
+         *  sets flags in this case.
+         */
+        VMSTATE_VBUFFER_MULTIPLY(mac_table.macs, VirtIONet,
+                                0, mac_table_fits, mac_table.in_use,
+                                 ETH_ALEN),
+        VMSTATE_UNUSED_VARRAY_UINT32(VirtIONet, mac_table_doesnt_fit, 0,
+                                     mac_table.in_use, ETH_ALEN),
+
+        /* Note: This is an array of uint32's that's always been saved as a
+         * buffer; hold onto your endiannesses; it's actually used as a bitmap
+         * but based on the uint.
+         */
+        VMSTATE_BUFFER_POINTER_UNSAFE(vlans, VirtIONet, 0, MAX_VLAN >> 3),
+        VMSTATE_WITH_TMP(VirtIONet, struct VirtIONetMigTmp,
+                         vmstate_virtio_net_has_vnet),
+        VMSTATE_UINT8(mac_table.multi_overflow, VirtIONet),
+        VMSTATE_UINT8(mac_table.uni_overflow, VirtIONet),
+        VMSTATE_UINT8(alluni, VirtIONet),
+        VMSTATE_UINT8(nomulti, VirtIONet),
+        VMSTATE_UINT8(nouni, VirtIONet),
+        VMSTATE_UINT8(nobcast, VirtIONet),
+        VMSTATE_WITH_TMP(VirtIONet, struct VirtIONetMigTmp,
+                         vmstate_virtio_net_has_ufo),
+        VMSTATE_SINGLE_TEST(max_queue_pairs, VirtIONet, max_queue_pairs_gt_1, 0,
+                            vmstate_info_uint16_equal, uint16_t),
+        VMSTATE_UINT16_TEST(curr_queue_pairs, VirtIONet, max_queue_pairs_gt_1),
+        VMSTATE_WITH_TMP(VirtIONet, struct VirtIONetMigTmp,
+                         vmstate_virtio_net_tx_waiting),
+        VMSTATE_UINT64_TEST(curr_guest_offloads, VirtIONet,
+                            has_ctrl_guest_offloads),
+        VMSTATE_END_OF_LIST()
+   },
+    .subsections = (const VMStateDescription * []) {
+        &vmstate_virtio_net_rss,
+        NULL
+    }
+};
+
+static NetClientInfo net_virtio_info = {
+    .type = NET_CLIENT_DRIVER_NIC,
+    .size = sizeof(NICState),
+    .can_receive = virtio_net_can_receive,
+    .receive = virtio_net_receive,
+    .link_status_changed = virtio_net_set_link_status,
+    .query_rx_filter = virtio_net_query_rxfilter,
+    .announce = virtio_net_announce,
+};
+
+static bool virtio_net_guest_notifier_pending(VirtIODevice *vdev, int idx)
+{
+    VirtIONet *n = VIRTIO_NET(vdev);
+    NetClientState *nc;
+    assert(n->vhost_started);
+    if (!virtio_vdev_has_feature(vdev, VIRTIO_NET_F_MQ) && idx == 2) {
+        /* Must guard against invalid features and bogus queue index
+         * from being set by malicious guest, or penetrated through
+         * buggy migration stream.
+         */
+        if (!virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ)) {
+            qemu_log_mask(LOG_GUEST_ERROR,
+                          "%s: bogus vq index ignored\n", __func__);
+            return false;
+        }
+        nc = qemu_get_subqueue(n->nic, n->max_queue_pairs);
+    } else {
+        nc = qemu_get_subqueue(n->nic, vq2q(idx));
+    }
+    return vhost_net_virtqueue_pending(get_vhost_net(nc->peer), idx);
+}
+
+static void virtio_net_guest_notifier_mask(VirtIODevice *vdev, int idx,
+                                           bool mask)
+{
+    VirtIONet *n = VIRTIO_NET(vdev);
+    NetClientState *nc;
+    assert(n->vhost_started);
+    if (!virtio_vdev_has_feature(vdev, VIRTIO_NET_F_MQ) && idx == 2) {
+        /* Must guard against invalid features and bogus queue index
+         * from being set by malicious guest, or penetrated through
+         * buggy migration stream.
+         */
+        if (!virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ)) {
+            qemu_log_mask(LOG_GUEST_ERROR,
+                          "%s: bogus vq index ignored\n", __func__);
+            return;
+        }
+        nc = qemu_get_subqueue(n->nic, n->max_queue_pairs);
+    } else {
+        nc = qemu_get_subqueue(n->nic, vq2q(idx));
+    }
+    vhost_net_virtqueue_mask(get_vhost_net(nc->peer),
+                             vdev, idx, mask);
+}
+
+static void virtio_net_set_config_size(VirtIONet *n, uint64_t host_features)
+{
+    virtio_add_feature(&host_features, VIRTIO_NET_F_MAC);
+
+    n->config_size = virtio_get_config_size(&cfg_size_params, host_features);
+}
+
+void virtio_net_set_netclient_name(VirtIONet *n, const char *name,
+                                   const char *type)
+{
+    /*
+     * The name can be NULL, the netclient name will be type.x.
+     */
+    assert(type != NULL);
+
+    g_free(n->netclient_name);
+    g_free(n->netclient_type);
+    n->netclient_name = g_strdup(name);
+    n->netclient_type = g_strdup(type);
+}
+
+static bool failover_unplug_primary(VirtIONet *n, DeviceState *dev)
+{
+    HotplugHandler *hotplug_ctrl;
+    PCIDevice *pci_dev;
+    Error *err = NULL;
+
+    hotplug_ctrl = qdev_get_hotplug_handler(dev);
+    if (hotplug_ctrl) {
+        pci_dev = PCI_DEVICE(dev);
+        pci_dev->partially_hotplugged = true;
+        hotplug_handler_unplug_request(hotplug_ctrl, dev, &err);
+        if (err) {
+            error_report_err(err);
+            return false;
+        }
+    } else {
+        return false;
+    }
+    return true;
+}
+
+static bool failover_replug_primary(VirtIONet *n, DeviceState *dev,
+                                    Error **errp)
+{
+    Error *err = NULL;
+    HotplugHandler *hotplug_ctrl;
+    PCIDevice *pdev = PCI_DEVICE(dev);
+    BusState *primary_bus;
+
+    if (!pdev->partially_hotplugged) {
+        return true;
+    }
+    primary_bus = dev->parent_bus;
+    if (!primary_bus) {
+        error_setg(errp, "virtio_net: couldn't find primary bus");
+        return false;
+    }
+    qdev_set_parent_bus(dev, primary_bus, &error_abort);
+    qatomic_set(&n->failover_primary_hidden, false);
+    hotplug_ctrl = qdev_get_hotplug_handler(dev);
+    if (hotplug_ctrl) {
+        hotplug_handler_pre_plug(hotplug_ctrl, dev, &err);
+        if (err) {
+            goto out;
+        }
+        hotplug_handler_plug(hotplug_ctrl, dev, &err);
+    }
+    pdev->partially_hotplugged = false;
+
+out:
+    error_propagate(errp, err);
+    return !err;
+}
+
+static void virtio_net_handle_migration_primary(VirtIONet *n, MigrationState *s)
+{
+    bool should_be_hidden;
+    Error *err = NULL;
+    DeviceState *dev = failover_find_primary_device(n);
+
+    if (!dev) {
+        return;
+    }
+
+    should_be_hidden = qatomic_read(&n->failover_primary_hidden);
+
+    if (migration_in_setup(s) && !should_be_hidden) {
+        if (failover_unplug_primary(n, dev)) {
+            vmstate_unregister(VMSTATE_IF(dev), qdev_get_vmsd(dev), dev);
+            qapi_event_send_unplug_primary(dev->id);
+            qatomic_set(&n->failover_primary_hidden, true);
+        } else {
+            warn_report("couldn't unplug primary device");
+        }
+    } else if (migration_has_failed(s)) {
+        /* We already unplugged the device let's plug it back */
+        if (!failover_replug_primary(n, dev, &err)) {
+            if (err) {
+                error_report_err(err);
+            }
+        }
+    }
+}
+
+static void virtio_net_migration_state_notifier(Notifier *notifier, void *data)
+{
+    MigrationState *s = data;
+    VirtIONet *n = container_of(notifier, VirtIONet, migration_state);
+    virtio_net_handle_migration_primary(n, s);
+}
+
+static bool failover_hide_primary_device(DeviceListener *listener,
+                                         const QDict *device_opts,
+                                         bool from_json,
+                                         Error **errp)
+{
+    VirtIONet *n = container_of(listener, VirtIONet, primary_listener);
+    const char *standby_id;
+
+    if (!device_opts) {
+        return false;
+    }
+
+    if (!qdict_haskey(device_opts, "failover_pair_id")) {
+        return false;
+    }
+
+    if (!qdict_haskey(device_opts, "id")) {
+        error_setg(errp, "Device with failover_pair_id needs to have id");
+        return false;
+    }
+
+    standby_id = qdict_get_str(device_opts, "failover_pair_id");
+    if (g_strcmp0(standby_id, n->netclient_name) != 0) {
+        return false;
+    }
+
+    /*
+     * The hide helper can be called several times for a given device.
+     * Check there is only one primary for a virtio-net device but
+     * don't duplicate the qdict several times if it's called for the same
+     * device.
+     */
+    if (n->primary_opts) {
+        const char *old, *new;
+        /* devices with failover_pair_id always have an id */
+        old = qdict_get_str(n->primary_opts, "id");
+        new = qdict_get_str(device_opts, "id");
+        if (strcmp(old, new) != 0) {
+            error_setg(errp, "Cannot attach more than one primary device to "
+                       "'%s': '%s' and '%s'", n->netclient_name, old, new);
+            return false;
+        }
+    } else {
+        n->primary_opts = qdict_clone_shallow(device_opts);
+        n->primary_opts_from_json = from_json;
+    }
+
+    /* failover_primary_hidden is set during feature negotiation */
+    return qatomic_read(&n->failover_primary_hidden);
+}
+
+static void virtio_net_device_realize(DeviceState *dev, Error **errp)
+{
+    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+    VirtIONet *n = VIRTIO_NET(dev);
+    NetClientState *nc;
+    int i;
+
+    if (n->net_conf.mtu) {
+        n->host_features |= (1ULL << VIRTIO_NET_F_MTU);
+    }
+
+    if (n->net_conf.duplex_str) {
+        if (strncmp(n->net_conf.duplex_str, "half", 5) == 0) {
+            n->net_conf.duplex = DUPLEX_HALF;
+        } else if (strncmp(n->net_conf.duplex_str, "full", 5) == 0) {
+            n->net_conf.duplex = DUPLEX_FULL;
+        } else {
+            error_setg(errp, "'duplex' must be 'half' or 'full'");
+            return;
+        }
+        n->host_features |= (1ULL << VIRTIO_NET_F_SPEED_DUPLEX);
+    } else {
+        n->net_conf.duplex = DUPLEX_UNKNOWN;
+    }
+
+    if (n->net_conf.speed < SPEED_UNKNOWN) {
+        error_setg(errp, "'speed' must be between 0 and INT_MAX");
+        return;
+    }
+    if (n->net_conf.speed >= 0) {
+        n->host_features |= (1ULL << VIRTIO_NET_F_SPEED_DUPLEX);
+    }
+
+    if (n->failover) {
+        n->primary_listener.hide_device = failover_hide_primary_device;
+        qatomic_set(&n->failover_primary_hidden, true);
+        device_listener_register(&n->primary_listener);
+        n->migration_state.notify = virtio_net_migration_state_notifier;
+        add_migration_state_change_notifier(&n->migration_state);
+        n->host_features |= (1ULL << VIRTIO_NET_F_STANDBY);
+    }
+
+    virtio_net_set_config_size(n, n->host_features);
+    virtio_init(vdev, VIRTIO_ID_NET, n->config_size);
+
+    /*
+     * We set a lower limit on RX queue size to what it always was.
+     * Guests that want a smaller ring can always resize it without
+     * help from us (using virtio 1 and up).
+     */
+    if (n->net_conf.rx_queue_size < VIRTIO_NET_RX_QUEUE_MIN_SIZE ||
+        n->net_conf.rx_queue_size > VIRTQUEUE_MAX_SIZE ||
+        !is_power_of_2(n->net_conf.rx_queue_size)) {
+        error_setg(errp, "Invalid rx_queue_size (= %" PRIu16 "), "
+                   "must be a power of 2 between %d and %d.",
+                   n->net_conf.rx_queue_size, VIRTIO_NET_RX_QUEUE_MIN_SIZE,
+                   VIRTQUEUE_MAX_SIZE);
+        virtio_cleanup(vdev);
+        return;
+    }
+
+    if (n->net_conf.tx_queue_size < VIRTIO_NET_TX_QUEUE_MIN_SIZE ||
+        n->net_conf.tx_queue_size > VIRTQUEUE_MAX_SIZE ||
+        !is_power_of_2(n->net_conf.tx_queue_size)) {
+        error_setg(errp, "Invalid tx_queue_size (= %" PRIu16 "), "
+                   "must be a power of 2 between %d and %d",
+                   n->net_conf.tx_queue_size, VIRTIO_NET_TX_QUEUE_MIN_SIZE,
+                   VIRTQUEUE_MAX_SIZE);
+        virtio_cleanup(vdev);
+        return;
+    }
+
+    n->max_ncs = MAX(n->nic_conf.peers.queues, 1);
+
+    /*
+     * Figure out the datapath queue pairs since the backend could
+     * provide control queue via peers as well.
+     */
+    if (n->nic_conf.peers.queues) {
+        for (i = 0; i < n->max_ncs; i++) {
+            if (n->nic_conf.peers.ncs[i]->is_datapath) {
+                ++n->max_queue_pairs;
+            }
+        }
+    }
+    n->max_queue_pairs = MAX(n->max_queue_pairs, 1);
+
+    if (n->max_queue_pairs * 2 + 1 > VIRTIO_QUEUE_MAX) {
+        error_setg(errp, "Invalid number of queue pairs (= %" PRIu32 "), "
+                   "must be a positive integer less than %d.",
+                   n->max_queue_pairs, (VIRTIO_QUEUE_MAX - 1) / 2);
+        virtio_cleanup(vdev);
+        return;
+    }
+    n->vqs = g_new0(VirtIONetQueue, n->max_queue_pairs);
+    n->curr_queue_pairs = 1;
+    n->tx_timeout = n->net_conf.txtimer;
+
+    if (n->net_conf.tx && strcmp(n->net_conf.tx, "timer")
+                       && strcmp(n->net_conf.tx, "bh")) {
+        warn_report("virtio-net: "
+                    "Unknown option tx=%s, valid options: \"timer\" \"bh\"",
+                    n->net_conf.tx);
+        error_printf("Defaulting to \"bh\"");
+    }
+
+    n->net_conf.tx_queue_size = MIN(virtio_net_max_tx_queue_size(n),
+                                    n->net_conf.tx_queue_size);
+
+    for (i = 0; i < n->max_queue_pairs; i++) {
+        virtio_net_add_queue(n, i);
+    }
+
+    n->ctrl_vq = virtio_add_queue(vdev, 64, virtio_net_handle_ctrl);
+    qemu_macaddr_default_if_unset(&n->nic_conf.macaddr);
+    memcpy(&n->mac[0], &n->nic_conf.macaddr, sizeof(n->mac));
+    n->status = VIRTIO_NET_S_LINK_UP;
+    qemu_announce_timer_reset(&n->announce_timer, migrate_announce_params(),
+                              QEMU_CLOCK_VIRTUAL,
+                              virtio_net_announce_timer, n);
+    n->announce_timer.round = 0;
+
+    if (n->netclient_type) {
+        /*
+         * Happen when virtio_net_set_netclient_name has been called.
+         */
+        n->nic = qemu_new_nic(&net_virtio_info, &n->nic_conf,
+                              n->netclient_type, n->netclient_name, n);
+    } else {
+        n->nic = qemu_new_nic(&net_virtio_info, &n->nic_conf,
+                              object_get_typename(OBJECT(dev)), dev->id, n);
+    }
+
+    for (i = 0; i < n->max_queue_pairs; i++) {
+        n->nic->ncs[i].do_not_pad = true;
+    }
+
+    peer_test_vnet_hdr(n);
+    if (peer_has_vnet_hdr(n)) {
+        for (i = 0; i < n->max_queue_pairs; i++) {
+            qemu_using_vnet_hdr(qemu_get_subqueue(n->nic, i)->peer, true);
+        }
+        n->host_hdr_len = sizeof(struct virtio_net_hdr);
+    } else {
+        n->host_hdr_len = 0;
+    }
+
+    qemu_format_nic_info_str(qemu_get_queue(n->nic), n->nic_conf.macaddr.a);
+
+    n->vqs[0].tx_waiting = 0;
+    n->tx_burst = n->net_conf.txburst;
+    virtio_net_set_mrg_rx_bufs(n, 0, 0, 0);
+    n->promisc = 1; /* for compatibility */
+
+    n->mac_table.macs = g_malloc0(MAC_TABLE_ENTRIES * ETH_ALEN);
+
+    n->vlans = g_malloc0(MAX_VLAN >> 3);
+
+    nc = qemu_get_queue(n->nic);
+    nc->rxfilter_notify_enabled = 1;
+
+   if (nc->peer && nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_VDPA) {
+        struct virtio_net_config netcfg = {};
+        memcpy(&netcfg.mac, &n->nic_conf.macaddr, ETH_ALEN);
+        vhost_net_set_config(get_vhost_net(nc->peer),
+            (uint8_t *)&netcfg, 0, ETH_ALEN, VHOST_SET_CONFIG_TYPE_MASTER);
+    }
+    QTAILQ_INIT(&n->rsc_chains);
+    n->qdev = dev;
+
+    net_rx_pkt_init(&n->rx_pkt, false);
+
+    if (virtio_has_feature(n->host_features, VIRTIO_NET_F_RSS)) {
+        virtio_net_load_ebpf(n);
+    }
+}
+
+static void virtio_net_device_unrealize(DeviceState *dev)
+{
+    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+    VirtIONet *n = VIRTIO_NET(dev);
+    int i, max_queue_pairs;
+
+    if (virtio_has_feature(n->host_features, VIRTIO_NET_F_RSS)) {
+        virtio_net_unload_ebpf(n);
+    }
+
+    /* This will stop vhost backend if appropriate. */
+    virtio_net_set_status(vdev, 0);
+
+    g_free(n->netclient_name);
+    n->netclient_name = NULL;
+    g_free(n->netclient_type);
+    n->netclient_type = NULL;
+
+    g_free(n->mac_table.macs);
+    g_free(n->vlans);
+
+    if (n->failover) {
+        qobject_unref(n->primary_opts);
+        device_listener_unregister(&n->primary_listener);
+        remove_migration_state_change_notifier(&n->migration_state);
+    } else {
+        assert(n->primary_opts == NULL);
+    }
+
+    max_queue_pairs = n->multiqueue ? n->max_queue_pairs : 1;
+    for (i = 0; i < max_queue_pairs; i++) {
+        virtio_net_del_queue(n, i);
+    }
+    /* delete also control vq */
+    virtio_del_queue(vdev, max_queue_pairs * 2);
+    qemu_announce_timer_del(&n->announce_timer, false);
+    g_free(n->vqs);
+    qemu_del_nic(n->nic);
+    virtio_net_rsc_cleanup(n);
+    g_free(n->rss_data.indirections_table);
+    net_rx_pkt_uninit(n->rx_pkt);
+    virtio_cleanup(vdev);
+}
+
+static void virtio_net_instance_init(Object *obj)
+{
+    VirtIONet *n = VIRTIO_NET(obj);
+
+    /*
+     * The default config_size is sizeof(struct virtio_net_config).
+     * Can be overriden with virtio_net_set_config_size.
+     */
+    n->config_size = sizeof(struct virtio_net_config);
+    device_add_bootindex_property(obj, &n->nic_conf.bootindex,
+                                  "bootindex", "/ethernet-phy@0",
+                                  DEVICE(n));
+
+    ebpf_rss_init(&n->ebpf_rss);
+}
+
+static int virtio_net_pre_save(void *opaque)
+{
+    VirtIONet *n = opaque;
+
+    /* At this point, backend must be stopped, otherwise
+     * it might keep writing to memory. */
+    assert(!n->vhost_started);
+
+    return 0;
+}
+
+static bool primary_unplug_pending(void *opaque)
+{
+    DeviceState *dev = opaque;
+    DeviceState *primary;
+    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+    VirtIONet *n = VIRTIO_NET(vdev);
+
+    if (!virtio_vdev_has_feature(vdev, VIRTIO_NET_F_STANDBY)) {
+        return false;
+    }
+    primary = failover_find_primary_device(n);
+    return primary ? primary->pending_deleted_event : false;
+}
+
+static bool dev_unplug_pending(void *opaque)
+{
+    DeviceState *dev = opaque;
+    VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(dev);
+
+    return vdc->primary_unplug_pending(dev);
+}
+
+static struct vhost_dev *virtio_net_get_vhost(VirtIODevice *vdev)
+{
+    VirtIONet *n = VIRTIO_NET(vdev);
+    NetClientState *nc = qemu_get_queue(n->nic);
+    struct vhost_net *net = get_vhost_net(nc->peer);
+    return &net->dev;
+}
+
+static const VMStateDescription vmstate_virtio_net = {
+    .name = "virtio-net",
+    .minimum_version_id = VIRTIO_NET_VM_VERSION,
+    .version_id = VIRTIO_NET_VM_VERSION,
+    .fields = (VMStateField[]) {
+        VMSTATE_VIRTIO_DEVICE,
+        VMSTATE_END_OF_LIST()
+    },
+    .pre_save = virtio_net_pre_save,
+    .dev_unplug_pending = dev_unplug_pending,
+};
+
+static Property virtio_net_properties[] = {
+    DEFINE_PROP_BIT64("csum", VirtIONet, host_features,
+                    VIRTIO_NET_F_CSUM, true),
+    DEFINE_PROP_BIT64("guest_csum", VirtIONet, host_features,
+                    VIRTIO_NET_F_GUEST_CSUM, true),
+    DEFINE_PROP_BIT64("gso", VirtIONet, host_features, VIRTIO_NET_F_GSO, true),
+    DEFINE_PROP_BIT64("guest_tso4", VirtIONet, host_features,
+                    VIRTIO_NET_F_GUEST_TSO4, true),
+    DEFINE_PROP_BIT64("guest_tso6", VirtIONet, host_features,
+                    VIRTIO_NET_F_GUEST_TSO6, true),
+    DEFINE_PROP_BIT64("guest_ecn", VirtIONet, host_features,
+                    VIRTIO_NET_F_GUEST_ECN, true),
+    DEFINE_PROP_BIT64("guest_ufo", VirtIONet, host_features,
+                    VIRTIO_NET_F_GUEST_UFO, true),
+    DEFINE_PROP_BIT64("guest_announce", VirtIONet, host_features,
+                    VIRTIO_NET_F_GUEST_ANNOUNCE, true),
+    DEFINE_PROP_BIT64("host_tso4", VirtIONet, host_features,
+                    VIRTIO_NET_F_HOST_TSO4, true),
+    DEFINE_PROP_BIT64("host_tso6", VirtIONet, host_features,
+                    VIRTIO_NET_F_HOST_TSO6, true),
+    DEFINE_PROP_BIT64("host_ecn", VirtIONet, host_features,
+                    VIRTIO_NET_F_HOST_ECN, true),
+    DEFINE_PROP_BIT64("host_ufo", VirtIONet, host_features,
+                    VIRTIO_NET_F_HOST_UFO, true),
+    DEFINE_PROP_BIT64("mrg_rxbuf", VirtIONet, host_features,
+                    VIRTIO_NET_F_MRG_RXBUF, true),
+    DEFINE_PROP_BIT64("status", VirtIONet, host_features,
+                    VIRTIO_NET_F_STATUS, true),
+    DEFINE_PROP_BIT64("ctrl_vq", VirtIONet, host_features,
+                    VIRTIO_NET_F_CTRL_VQ, true),
+    DEFINE_PROP_BIT64("ctrl_rx", VirtIONet, host_features,
+                    VIRTIO_NET_F_CTRL_RX, true),
+    DEFINE_PROP_BIT64("ctrl_vlan", VirtIONet, host_features,
+                    VIRTIO_NET_F_CTRL_VLAN, true),
+    DEFINE_PROP_BIT64("ctrl_rx_extra", VirtIONet, host_features,
+                    VIRTIO_NET_F_CTRL_RX_EXTRA, true),
+    DEFINE_PROP_BIT64("ctrl_mac_addr", VirtIONet, host_features,
+                    VIRTIO_NET_F_CTRL_MAC_ADDR, true),
+    DEFINE_PROP_BIT64("ctrl_guest_offloads", VirtIONet, host_features,
+                    VIRTIO_NET_F_CTRL_GUEST_OFFLOADS, true),
+    DEFINE_PROP_BIT64("mq", VirtIONet, host_features, VIRTIO_NET_F_MQ, false),
+    DEFINE_PROP_BIT64("rss", VirtIONet, host_features,
+                    VIRTIO_NET_F_RSS, false),
+    DEFINE_PROP_BIT64("hash", VirtIONet, host_features,
+                    VIRTIO_NET_F_HASH_REPORT, false),
+    DEFINE_PROP_BIT64("guest_rsc_ext", VirtIONet, host_features,
+                    VIRTIO_NET_F_RSC_EXT, false),
+    DEFINE_PROP_UINT32("rsc_interval", VirtIONet, rsc_timeout,
+                       VIRTIO_NET_RSC_DEFAULT_INTERVAL),
+    DEFINE_NIC_PROPERTIES(VirtIONet, nic_conf),
+    DEFINE_PROP_UINT32("x-txtimer", VirtIONet, net_conf.txtimer,
+                       TX_TIMER_INTERVAL),
+    DEFINE_PROP_INT32("x-txburst", VirtIONet, net_conf.txburst, TX_BURST),
+    DEFINE_PROP_STRING("tx", VirtIONet, net_conf.tx),
+    DEFINE_PROP_UINT16("rx_queue_size", VirtIONet, net_conf.rx_queue_size,
+                       VIRTIO_NET_RX_QUEUE_DEFAULT_SIZE),
+    DEFINE_PROP_UINT16("tx_queue_size", VirtIONet, net_conf.tx_queue_size,
+                       VIRTIO_NET_TX_QUEUE_DEFAULT_SIZE),
+    DEFINE_PROP_UINT16("host_mtu", VirtIONet, net_conf.mtu, 0),
+    DEFINE_PROP_BOOL("x-mtu-bypass-backend", VirtIONet, mtu_bypass_backend,
+                     true),
+    DEFINE_PROP_INT32("speed", VirtIONet, net_conf.speed, SPEED_UNKNOWN),
+    DEFINE_PROP_STRING("duplex", VirtIONet, net_conf.duplex_str),
+    DEFINE_PROP_BOOL("failover", VirtIONet, failover, false),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void virtio_net_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
+
+    device_class_set_props(dc, virtio_net_properties);
+    dc->vmsd = &vmstate_virtio_net;
+    set_bit(DEVICE_CATEGORY_NETWORK, dc->categories);
+    vdc->realize = virtio_net_device_realize;
+    vdc->unrealize = virtio_net_device_unrealize;
+    vdc->get_config = virtio_net_get_config;
+    vdc->set_config = virtio_net_set_config;
+    vdc->get_features = virtio_net_get_features;
+    vdc->set_features = virtio_net_set_features;
+    vdc->bad_features = virtio_net_bad_features;
+    vdc->reset = virtio_net_reset;
+    vdc->queue_reset = virtio_net_queue_reset;
+    vdc->queue_enable = virtio_net_queue_enable;
+    vdc->set_status = virtio_net_set_status;
+    vdc->guest_notifier_mask = virtio_net_guest_notifier_mask;
+    vdc->guest_notifier_pending = virtio_net_guest_notifier_pending;
+    vdc->legacy_features |= (0x1 << VIRTIO_NET_F_GSO);
+    vdc->post_load = virtio_net_post_load_virtio;
+    vdc->vmsd = &vmstate_virtio_net_device;
+    vdc->primary_unplug_pending = primary_unplug_pending;
+    vdc->get_vhost = virtio_net_get_vhost;
+}
+
+static const TypeInfo virtio_net_info = {
+    .name = TYPE_VIRTIO_NET,
+    .parent = TYPE_VIRTIO_DEVICE,
+    .instance_size = sizeof(VirtIONet),
+    .instance_init = virtio_net_instance_init,
+    .class_init = virtio_net_class_init,
+};
+
+static void virtio_register_types(void)
+{
+    type_register_static(&virtio_net_info);
+}
+
+type_init(virtio_register_types)