diff --git a/sys/dev/virtio/network/if_vtnet.c b/sys/dev/virtio/network/if_vtnet.c
index e3a42413d5cd..dc232d769fa6 100644
--- a/sys/dev/virtio/network/if_vtnet.c
+++ b/sys/dev/virtio/network/if_vtnet.c
@@ -1,4397 +1,4403 @@
 /*-
  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
  *
  * Copyright (c) 2011, Bryan Venteicher <bryanv@FreeBSD.org>
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice unmodified, this list of conditions, and the following
  *    disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 /* Driver for VirtIO network devices. */
 
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
 #include <sys/param.h>
 #include <sys/eventhandler.h>
 #include <sys/systm.h>
 #include <sys/kernel.h>
 #include <sys/sockio.h>
 #include <sys/mbuf.h>
 #include <sys/malloc.h>
 #include <sys/module.h>
 #include <sys/socket.h>
 #include <sys/sysctl.h>
 #include <sys/random.h>
 #include <sys/sglist.h>
 #include <sys/lock.h>
 #include <sys/mutex.h>
 #include <sys/taskqueue.h>
 #include <sys/smp.h>
 #include <machine/smp.h>
 
 #include <vm/uma.h>
 
 #include <net/debugnet.h>
 #include <net/ethernet.h>
 #include <net/pfil.h>
 #include <net/if.h>
 #include <net/if_var.h>
 #include <net/if_arp.h>
 #include <net/if_dl.h>
 #include <net/if_types.h>
 #include <net/if_media.h>
 #include <net/if_vlan_var.h>
 
 #include <net/bpf.h>
 
 #include <netinet/in_systm.h>
 #include <netinet/in.h>
 #include <netinet/ip.h>
 #include <netinet/ip6.h>
 #include <netinet6/ip6_var.h>
 #include <netinet/udp.h>
 #include <netinet/tcp.h>
 #include <netinet/tcp_lro.h>
 
 #include <machine/bus.h>
 #include <machine/resource.h>
 #include <sys/bus.h>
 #include <sys/rman.h>
 
 #include <dev/virtio/virtio.h>
 #include <dev/virtio/virtqueue.h>
 #include <dev/virtio/network/virtio_net.h>
 #include <dev/virtio/network/if_vtnetvar.h>
 #include "virtio_if.h"
 
 #include "opt_inet.h"
 #include "opt_inet6.h"
 
 #if defined(INET) || defined(INET6)
 #include <machine/in_cksum.h>
 #endif
 
 static int	vtnet_modevent(module_t, int, void *);
 
 static int	vtnet_probe(device_t);
 static int	vtnet_attach(device_t);
 static int	vtnet_detach(device_t);
 static int	vtnet_suspend(device_t);
 static int	vtnet_resume(device_t);
 static int	vtnet_shutdown(device_t);
 static int	vtnet_attach_completed(device_t);
 static int	vtnet_config_change(device_t);
 
 static void	vtnet_negotiate_features(struct vtnet_softc *);
 static void	vtnet_setup_features(struct vtnet_softc *);
 static int	vtnet_init_rxq(struct vtnet_softc *, int);
 static int	vtnet_init_txq(struct vtnet_softc *, int);
 static int	vtnet_alloc_rxtx_queues(struct vtnet_softc *);
 static void	vtnet_free_rxtx_queues(struct vtnet_softc *);
 static int	vtnet_alloc_rx_filters(struct vtnet_softc *);
 static void	vtnet_free_rx_filters(struct vtnet_softc *);
 static int	vtnet_alloc_virtqueues(struct vtnet_softc *);
 static int	vtnet_alloc_interface(struct vtnet_softc *);
 static int	vtnet_setup_interface(struct vtnet_softc *);
 static int	vtnet_ioctl_mtu(struct vtnet_softc *, int);
 static int	vtnet_ioctl_ifflags(struct vtnet_softc *);
 static int	vtnet_ioctl_multi(struct vtnet_softc *);
 static int	vtnet_ioctl_ifcap(struct vtnet_softc *, struct ifreq *);
 static int	vtnet_ioctl(struct ifnet *, u_long, caddr_t);
 static uint64_t	vtnet_get_counter(struct ifnet *, ift_counter);
 
 static int	vtnet_rxq_populate(struct vtnet_rxq *);
 static void	vtnet_rxq_free_mbufs(struct vtnet_rxq *);
 static struct mbuf *
 		vtnet_rx_alloc_buf(struct vtnet_softc *, int , struct mbuf **);
 static int	vtnet_rxq_replace_lro_nomrg_buf(struct vtnet_rxq *,
 		    struct mbuf *, int);
 static int	vtnet_rxq_replace_buf(struct vtnet_rxq *, struct mbuf *, int);
 static int	vtnet_rxq_enqueue_buf(struct vtnet_rxq *, struct mbuf *);
 static int	vtnet_rxq_new_buf(struct vtnet_rxq *);
 static int	vtnet_rxq_csum_needs_csum(struct vtnet_rxq *, struct mbuf *,
 		     uint16_t, int, struct virtio_net_hdr *);
 static int	vtnet_rxq_csum_data_valid(struct vtnet_rxq *, struct mbuf *,
 		     uint16_t, int, struct virtio_net_hdr *);
 static int	vtnet_rxq_csum(struct vtnet_rxq *, struct mbuf *,
 		     struct virtio_net_hdr *);
 static void	vtnet_rxq_discard_merged_bufs(struct vtnet_rxq *, int);
 static void	vtnet_rxq_discard_buf(struct vtnet_rxq *, struct mbuf *);
 static int	vtnet_rxq_merged_eof(struct vtnet_rxq *, struct mbuf *, int);
 static void	vtnet_rxq_input(struct vtnet_rxq *, struct mbuf *,
 		    struct virtio_net_hdr *);
 static int	vtnet_rxq_eof(struct vtnet_rxq *);
 static void	vtnet_rx_vq_process(struct vtnet_rxq *rxq, int tries);
 static void	vtnet_rx_vq_intr(void *);
 static void	vtnet_rxq_tq_intr(void *, int);
 
 static int	vtnet_txq_intr_threshold(struct vtnet_txq *);
 static int	vtnet_txq_below_threshold(struct vtnet_txq *);
 static int	vtnet_txq_notify(struct vtnet_txq *);
 static void	vtnet_txq_free_mbufs(struct vtnet_txq *);
 static int	vtnet_txq_offload_ctx(struct vtnet_txq *, struct mbuf *,
 		    int *, int *, int *);
 static int	vtnet_txq_offload_tso(struct vtnet_txq *, struct mbuf *, int,
 		    int, struct virtio_net_hdr *);
 static struct mbuf *
 		vtnet_txq_offload(struct vtnet_txq *, struct mbuf *,
 		    struct virtio_net_hdr *);
 static int	vtnet_txq_enqueue_buf(struct vtnet_txq *, struct mbuf **,
 		    struct vtnet_tx_header *);
 static int	vtnet_txq_encap(struct vtnet_txq *, struct mbuf **, int);
 #ifdef VTNET_LEGACY_TX
 static void	vtnet_start_locked(struct vtnet_txq *, struct ifnet *);
 static void	vtnet_start(struct ifnet *);
 #else
 static int	vtnet_txq_mq_start_locked(struct vtnet_txq *, struct mbuf *);
 static int	vtnet_txq_mq_start(struct ifnet *, struct mbuf *);
 static void	vtnet_txq_tq_deferred(void *, int);
 #endif
 static void	vtnet_txq_start(struct vtnet_txq *);
 static void	vtnet_txq_tq_intr(void *, int);
 static int	vtnet_txq_eof(struct vtnet_txq *);
 static void	vtnet_tx_vq_intr(void *);
 static void	vtnet_tx_start_all(struct vtnet_softc *);
 
 #ifndef VTNET_LEGACY_TX
 static void	vtnet_qflush(struct ifnet *);
 #endif
 
 static int	vtnet_watchdog(struct vtnet_txq *);
 static void	vtnet_accum_stats(struct vtnet_softc *,
 		    struct vtnet_rxq_stats *, struct vtnet_txq_stats *);
 static void	vtnet_tick(void *);
 
 static void	vtnet_start_taskqueues(struct vtnet_softc *);
 static void	vtnet_free_taskqueues(struct vtnet_softc *);
 static void	vtnet_drain_taskqueues(struct vtnet_softc *);
 
 static void	vtnet_drain_rxtx_queues(struct vtnet_softc *);
 static void	vtnet_stop_rendezvous(struct vtnet_softc *);
 static void	vtnet_stop(struct vtnet_softc *);
 static int	vtnet_virtio_reinit(struct vtnet_softc *);
 static void	vtnet_init_rx_filters(struct vtnet_softc *);
 static int	vtnet_init_rx_queues(struct vtnet_softc *);
 static int	vtnet_init_tx_queues(struct vtnet_softc *);
 static int	vtnet_init_rxtx_queues(struct vtnet_softc *);
 static void	vtnet_set_active_vq_pairs(struct vtnet_softc *);
 static void	vtnet_update_rx_offloads(struct vtnet_softc *);
 static int	vtnet_reinit(struct vtnet_softc *);
 static void	vtnet_init_locked(struct vtnet_softc *, int);
 static void	vtnet_init(void *);
 
 static void	vtnet_free_ctrl_vq(struct vtnet_softc *);
 static void	vtnet_exec_ctrl_cmd(struct vtnet_softc *, void *,
 		    struct sglist *, int, int);
 static int	vtnet_ctrl_mac_cmd(struct vtnet_softc *, uint8_t *);
 static int	vtnet_ctrl_guest_offloads(struct vtnet_softc *, uint64_t);
 static int	vtnet_ctrl_mq_cmd(struct vtnet_softc *, uint16_t);
 static int	vtnet_ctrl_rx_cmd(struct vtnet_softc *, uint8_t, int);
 static int	vtnet_set_promisc(struct vtnet_softc *, int);
 static int	vtnet_set_allmulti(struct vtnet_softc *, int);
 static void	vtnet_rx_filter(struct vtnet_softc *);
 static void	vtnet_rx_filter_mac(struct vtnet_softc *);
 static int	vtnet_exec_vlan_filter(struct vtnet_softc *, int, uint16_t);
 static void	vtnet_rx_filter_vlan(struct vtnet_softc *);
 static void	vtnet_update_vlan_filter(struct vtnet_softc *, int, uint16_t);
 static void	vtnet_register_vlan(void *, struct ifnet *, uint16_t);
 static void	vtnet_unregister_vlan(void *, struct ifnet *, uint16_t);
 
 static void	vtnet_update_speed_duplex(struct vtnet_softc *);
 static int	vtnet_is_link_up(struct vtnet_softc *);
 static void	vtnet_update_link_status(struct vtnet_softc *);
 static int	vtnet_ifmedia_upd(struct ifnet *);
 static void	vtnet_ifmedia_sts(struct ifnet *, struct ifmediareq *);
 static void	vtnet_get_macaddr(struct vtnet_softc *);
 static void	vtnet_set_macaddr(struct vtnet_softc *);
 static void	vtnet_attached_set_macaddr(struct vtnet_softc *);
 static void	vtnet_vlan_tag_remove(struct mbuf *);
 static void	vtnet_set_rx_process_limit(struct vtnet_softc *);
 
 static void	vtnet_setup_rxq_sysctl(struct sysctl_ctx_list *,
 		    struct sysctl_oid_list *, struct vtnet_rxq *);
 static void	vtnet_setup_txq_sysctl(struct sysctl_ctx_list *,
 		    struct sysctl_oid_list *, struct vtnet_txq *);
 static void	vtnet_setup_queue_sysctl(struct vtnet_softc *);
 static void	vtnet_load_tunables(struct vtnet_softc *);
 static void	vtnet_setup_sysctl(struct vtnet_softc *);
 
 static int	vtnet_rxq_enable_intr(struct vtnet_rxq *);
 static void	vtnet_rxq_disable_intr(struct vtnet_rxq *);
 static int	vtnet_txq_enable_intr(struct vtnet_txq *);
 static void	vtnet_txq_disable_intr(struct vtnet_txq *);
 static void	vtnet_enable_rx_interrupts(struct vtnet_softc *);
 static void	vtnet_enable_tx_interrupts(struct vtnet_softc *);
 static void	vtnet_enable_interrupts(struct vtnet_softc *);
 static void	vtnet_disable_rx_interrupts(struct vtnet_softc *);
 static void	vtnet_disable_tx_interrupts(struct vtnet_softc *);
 static void	vtnet_disable_interrupts(struct vtnet_softc *);
 
 static int	vtnet_tunable_int(struct vtnet_softc *, const char *, int);
 
 DEBUGNET_DEFINE(vtnet);
 
 #define vtnet_htog16(_sc, _val)	virtio_htog16(vtnet_modern(_sc), _val)
 #define vtnet_htog32(_sc, _val)	virtio_htog32(vtnet_modern(_sc), _val)
 #define vtnet_htog64(_sc, _val)	virtio_htog64(vtnet_modern(_sc), _val)
 #define vtnet_gtoh16(_sc, _val)	virtio_gtoh16(vtnet_modern(_sc), _val)
 #define vtnet_gtoh32(_sc, _val)	virtio_gtoh32(vtnet_modern(_sc), _val)
 #define vtnet_gtoh64(_sc, _val)	virtio_gtoh64(vtnet_modern(_sc), _val)
 
 /* Tunables. */
 static SYSCTL_NODE(_hw, OID_AUTO, vtnet, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
     "VirtIO Net driver parameters");
 
 static int vtnet_csum_disable = 0;
 TUNABLE_INT("hw.vtnet.csum_disable", &vtnet_csum_disable);
 SYSCTL_INT(_hw_vtnet, OID_AUTO, csum_disable, CTLFLAG_RDTUN,
     &vtnet_csum_disable, 0, "Disables receive and send checksum offload");
 
 static int vtnet_fixup_needs_csum = 0;
 SYSCTL_INT(_hw_vtnet, OID_AUTO, fixup_needs_csum, CTLFLAG_RDTUN,
     &vtnet_fixup_needs_csum, 0,
     "Calculate valid checksum for NEEDS_CSUM packets");
 
 static int vtnet_tso_disable = 0;
 TUNABLE_INT("hw.vtnet.tso_disable", &vtnet_tso_disable);
 SYSCTL_INT(_hw_vtnet, OID_AUTO, tso_disable, CTLFLAG_RDTUN, &vtnet_tso_disable,
     0, "Disables TCP Segmentation Offload");
 
 static int vtnet_lro_disable = 0;
 TUNABLE_INT("hw.vtnet.lro_disable", &vtnet_lro_disable);
 SYSCTL_INT(_hw_vtnet, OID_AUTO, lro_disable, CTLFLAG_RDTUN, &vtnet_lro_disable,
     0, "Disables TCP Large Receive Offload");
 
 static int vtnet_mq_disable = 0;
 TUNABLE_INT("hw.vtnet.mq_disable", &vtnet_mq_disable);
 SYSCTL_INT(_hw_vtnet, OID_AUTO, mq_disable, CTLFLAG_RDTUN, &vtnet_mq_disable,
     0, "Disables multiqueue support");
 
 static int vtnet_mq_max_pairs = VTNET_MAX_QUEUE_PAIRS;
 TUNABLE_INT("hw.vtnet.mq_max_pairs", &vtnet_mq_max_pairs);
 SYSCTL_INT(_hw_vtnet, OID_AUTO, mq_max_pairs, CTLFLAG_RDTUN,
     &vtnet_mq_max_pairs, 0, "Sets the maximum number of multiqueue pairs");
 
 static int vtnet_tso_maxlen = IP_MAXPACKET;
 TUNABLE_INT("hw.vtnet.tso_maxlen", &vtnet_tso_maxlen);
 SYSCTL_INT(_hw_vtnet, OID_AUTO, tso_maxlen, CTLFLAG_RDTUN,
     &vtnet_tso_maxlen, 0, "TSO burst limit");
 
 static int vtnet_rx_process_limit = 1024;
 TUNABLE_INT("hw.vtnet.rx_process_limit", &vtnet_rx_process_limit);
 SYSCTL_INT(_hw_vtnet, OID_AUTO, rx_process_limit, CTLFLAG_RDTUN,
     &vtnet_rx_process_limit, 0, "Limits RX segments processed in a single pass");
 
 static int vtnet_lro_entry_count = 128;
 SYSCTL_INT(_hw_vtnet, OID_AUTO, lro_entry_count, CTLFLAG_RDTUN,
     &vtnet_lro_entry_count, 0, "Software LRO entry count");
 
 /* Enable sorted LRO, and the depth of the mbuf queue. */
 static int vtnet_lro_mbufq_depth = 0;
 SYSCTL_UINT(_hw_vtnet, OID_AUTO, lro_mbufq_depth, CTLFLAG_RDTUN,
     &vtnet_lro_mbufq_depth, 0, "Depth of software LRO mbuf queue");
 
 static uma_zone_t vtnet_tx_header_zone;
 
 static struct virtio_feature_desc vtnet_feature_desc[] = {
 	{ VIRTIO_NET_F_CSUM,			"TxChecksum"		},
 	{ VIRTIO_NET_F_GUEST_CSUM,		"RxChecksum"		},
 	{ VIRTIO_NET_F_CTRL_GUEST_OFFLOADS,	"CtrlRxOffloads"	},
 	{ VIRTIO_NET_F_MAC,			"MAC"			},
 	{ VIRTIO_NET_F_GSO,			"TxGSO"			},
 	{ VIRTIO_NET_F_GUEST_TSO4,		"RxLROv4"		},
 	{ VIRTIO_NET_F_GUEST_TSO6,		"RxLROv6"		},
 	{ VIRTIO_NET_F_GUEST_ECN,		"RxLROECN"		},
 	{ VIRTIO_NET_F_GUEST_UFO,		"RxUFO"			},
 	{ VIRTIO_NET_F_HOST_TSO4,		"TxTSOv4"		},
 	{ VIRTIO_NET_F_HOST_TSO6,		"TxTSOv6"		},
 	{ VIRTIO_NET_F_HOST_ECN,		"TxTSOECN"		},
 	{ VIRTIO_NET_F_HOST_UFO,		"TxUFO"			},
 	{ VIRTIO_NET_F_MRG_RXBUF,		"MrgRxBuf"		},
 	{ VIRTIO_NET_F_STATUS,			"Status"		},
 	{ VIRTIO_NET_F_CTRL_VQ,			"CtrlVq"		},
 	{ VIRTIO_NET_F_CTRL_RX,			"CtrlRxMode"		},
 	{ VIRTIO_NET_F_CTRL_VLAN,		"CtrlVLANFilter"	},
 	{ VIRTIO_NET_F_CTRL_RX_EXTRA,		"CtrlRxModeExtra"	},
 	{ VIRTIO_NET_F_GUEST_ANNOUNCE,		"GuestAnnounce"		},
 	{ VIRTIO_NET_F_MQ,			"Multiqueue"		},
 	{ VIRTIO_NET_F_CTRL_MAC_ADDR,		"CtrlMacAddr"		},
 	{ VIRTIO_NET_F_SPEED_DUPLEX,		"SpeedDuplex"		},
 
 	{ 0, NULL }
 };
 
 static device_method_t vtnet_methods[] = {
 	/* Device methods. */
 	DEVMETHOD(device_probe,			vtnet_probe),
 	DEVMETHOD(device_attach,		vtnet_attach),
 	DEVMETHOD(device_detach,		vtnet_detach),
 	DEVMETHOD(device_suspend,		vtnet_suspend),
 	DEVMETHOD(device_resume,		vtnet_resume),
 	DEVMETHOD(device_shutdown,		vtnet_shutdown),
 
 	/* VirtIO methods. */
 	DEVMETHOD(virtio_attach_completed,	vtnet_attach_completed),
 	DEVMETHOD(virtio_config_change,		vtnet_config_change),
 
 	DEVMETHOD_END
 };
 
 #ifdef DEV_NETMAP
 #include <dev/netmap/if_vtnet_netmap.h>
 #endif
 
 static driver_t vtnet_driver = {
     .name = "vtnet",
     .methods = vtnet_methods,
     .size = sizeof(struct vtnet_softc)
 };
 static devclass_t vtnet_devclass;
 
 DRIVER_MODULE(vtnet, virtio_mmio, vtnet_driver, vtnet_devclass,
     vtnet_modevent, 0);
 DRIVER_MODULE(vtnet, virtio_pci, vtnet_driver, vtnet_devclass,
     vtnet_modevent, 0);
 MODULE_VERSION(vtnet, 1);
 MODULE_DEPEND(vtnet, virtio, 1, 1, 1);
 #ifdef DEV_NETMAP
 MODULE_DEPEND(vtnet, netmap, 1, 1, 1);
 #endif
 
 VIRTIO_SIMPLE_PNPTABLE(vtnet, VIRTIO_ID_NETWORK, "VirtIO Networking Adapter");
 VIRTIO_SIMPLE_PNPINFO(virtio_mmio, vtnet);
 VIRTIO_SIMPLE_PNPINFO(virtio_pci, vtnet);
 
 static int
 vtnet_modevent(module_t mod, int type, void *unused)
 {
 	int error = 0;
 	static int loaded = 0;
 
 	switch (type) {
 	case MOD_LOAD:
 		if (loaded++ == 0) {
 			vtnet_tx_header_zone = uma_zcreate("vtnet_tx_hdr",
 				sizeof(struct vtnet_tx_header),
 				NULL, NULL, NULL, NULL, 0, 0);
 #ifdef DEBUGNET
 			/*
 			 * We need to allocate from this zone in the transmit path, so ensure
 			 * that we have at least one item per header available.
 			 * XXX add a separate zone like we do for mbufs? otherwise we may alloc
 			 * buckets
 			 */
 			uma_zone_reserve(vtnet_tx_header_zone, DEBUGNET_MAX_IN_FLIGHT * 2);
 			uma_prealloc(vtnet_tx_header_zone, DEBUGNET_MAX_IN_FLIGHT * 2);
 #endif
 		}
 		break;
 	case MOD_QUIESCE:
 		if (uma_zone_get_cur(vtnet_tx_header_zone) > 0)
 			error = EBUSY;
 		break;
 	case MOD_UNLOAD:
 		if (--loaded == 0) {
 			uma_zdestroy(vtnet_tx_header_zone);
 			vtnet_tx_header_zone = NULL;
 		}
 		break;
 	case MOD_SHUTDOWN:
 		break;
 	default:
 		error = EOPNOTSUPP;
 		break;
 	}
 
 	return (error);
 }
 
 static int
 vtnet_probe(device_t dev)
 {
 	return (VIRTIO_SIMPLE_PROBE(dev, vtnet));
 }
 
 static int
 vtnet_attach(device_t dev)
 {
 	struct vtnet_softc *sc;
 	int error;
 
 	sc = device_get_softc(dev);
 	sc->vtnet_dev = dev;
 
 	virtio_set_feature_desc(dev, vtnet_feature_desc);
 
 	VTNET_CORE_LOCK_INIT(sc);
 	callout_init_mtx(&sc->vtnet_tick_ch, VTNET_CORE_MTX(sc), 0);
 	vtnet_load_tunables(sc);
 
 	error = vtnet_alloc_interface(sc);
 	if (error) {
 		device_printf(dev, "cannot allocate interface\n");
 		goto fail;
 	}
 
 	vtnet_setup_sysctl(sc);
 	vtnet_setup_features(sc);
 
 	error = vtnet_alloc_rx_filters(sc);
 	if (error) {
 		device_printf(dev, "cannot allocate Rx filters\n");
 		goto fail;
 	}
 
 	error = vtnet_alloc_rxtx_queues(sc);
 	if (error) {
 		device_printf(dev, "cannot allocate queues\n");
 		goto fail;
 	}
 
 	error = vtnet_alloc_virtqueues(sc);
 	if (error) {
 		device_printf(dev, "cannot allocate virtqueues\n");
 		goto fail;
 	}
 
 	error = vtnet_setup_interface(sc);
 	if (error) {
 		device_printf(dev, "cannot setup interface\n");
 		goto fail;
 	}
 
 	error = virtio_setup_intr(dev, INTR_TYPE_NET);
 	if (error) {
 		device_printf(dev, "cannot setup interrupts\n");
 		ether_ifdetach(sc->vtnet_ifp);
 		goto fail;
 	}
 
 #ifdef DEV_NETMAP
 	vtnet_netmap_attach(sc);
 #endif
 	vtnet_start_taskqueues(sc);
 
 fail:
 	if (error)
 		vtnet_detach(dev);
 
 	return (error);
 }
 
 static int
 vtnet_detach(device_t dev)
 {
 	struct vtnet_softc *sc;
 	struct ifnet *ifp;
 
 	sc = device_get_softc(dev);
 	ifp = sc->vtnet_ifp;
 
 	if (device_is_attached(dev)) {
 		VTNET_CORE_LOCK(sc);
 		vtnet_stop(sc);
 		VTNET_CORE_UNLOCK(sc);
 
 		callout_drain(&sc->vtnet_tick_ch);
 		vtnet_drain_taskqueues(sc);
 
 		ether_ifdetach(ifp);
 	}
 
 #ifdef DEV_NETMAP
 	netmap_detach(ifp);
 #endif
 
 	vtnet_free_taskqueues(sc);
 
 	if (sc->vtnet_vlan_attach != NULL) {
 		EVENTHANDLER_DEREGISTER(vlan_config, sc->vtnet_vlan_attach);
 		sc->vtnet_vlan_attach = NULL;
 	}
 	if (sc->vtnet_vlan_detach != NULL) {
 		EVENTHANDLER_DEREGISTER(vlan_unconfig, sc->vtnet_vlan_detach);
 		sc->vtnet_vlan_detach = NULL;
 	}
 
 	ifmedia_removeall(&sc->vtnet_media);
 
 	if (ifp != NULL) {
 		if_free(ifp);
 		sc->vtnet_ifp = NULL;
 	}
 
 	vtnet_free_rxtx_queues(sc);
 	vtnet_free_rx_filters(sc);
 
 	if (sc->vtnet_ctrl_vq != NULL)
 		vtnet_free_ctrl_vq(sc);
 
 	VTNET_CORE_LOCK_DESTROY(sc);
 
 	return (0);
 }
 
 static int
 vtnet_suspend(device_t dev)
 {
 	struct vtnet_softc *sc;
 
 	sc = device_get_softc(dev);
 
 	VTNET_CORE_LOCK(sc);
 	vtnet_stop(sc);
 	sc->vtnet_flags |= VTNET_FLAG_SUSPENDED;
 	VTNET_CORE_UNLOCK(sc);
 
 	return (0);
 }
 
 static int
 vtnet_resume(device_t dev)
 {
 	struct vtnet_softc *sc;
 	struct ifnet *ifp;
 
 	sc = device_get_softc(dev);
 	ifp = sc->vtnet_ifp;
 
 	VTNET_CORE_LOCK(sc);
 	if (ifp->if_flags & IFF_UP)
 		vtnet_init_locked(sc, 0);
 	sc->vtnet_flags &= ~VTNET_FLAG_SUSPENDED;
 	VTNET_CORE_UNLOCK(sc);
 
 	return (0);
 }
 
 static int
 vtnet_shutdown(device_t dev)
 {
 	/*
 	 * Suspend already does all of what we need to
 	 * do here; we just never expect to be resumed.
 	 */
 	return (vtnet_suspend(dev));
 }
 
 static int
 vtnet_attach_completed(device_t dev)
 {
 	struct vtnet_softc *sc;
 
 	sc = device_get_softc(dev);
 
 	VTNET_CORE_LOCK(sc);
 	vtnet_attached_set_macaddr(sc);
 	VTNET_CORE_UNLOCK(sc);
 
 	return (0);
 }
 
 static int
 vtnet_config_change(device_t dev)
 {
 	struct vtnet_softc *sc;
 
 	sc = device_get_softc(dev);
 
 	VTNET_CORE_LOCK(sc);
 	vtnet_update_link_status(sc);
 	if (sc->vtnet_link_active != 0)
 		vtnet_tx_start_all(sc);
 	VTNET_CORE_UNLOCK(sc);
 
 	return (0);
 }
 
 static void
 vtnet_negotiate_features(struct vtnet_softc *sc)
 {
 	device_t dev;
 	uint64_t features, negotiated_features;
 	int no_csum;
 
 	dev = sc->vtnet_dev;
 	features = virtio_bus_is_modern(dev) ? VTNET_MODERN_FEATURES :
 	    VTNET_LEGACY_FEATURES;
 
 	/*
 	 * TSO and LRO are only available when their corresponding checksum
 	 * offload feature is also negotiated.
 	 */
 	no_csum = vtnet_tunable_int(sc, "csum_disable", vtnet_csum_disable);
 	if (no_csum)
 		features &= ~(VIRTIO_NET_F_CSUM | VIRTIO_NET_F_GUEST_CSUM);
 	if (no_csum || vtnet_tunable_int(sc, "tso_disable", vtnet_tso_disable))
 		features &= ~VTNET_TSO_FEATURES;
 	if (no_csum || vtnet_tunable_int(sc, "lro_disable", vtnet_lro_disable))
 		features &= ~VTNET_LRO_FEATURES;
 
 #ifndef VTNET_LEGACY_TX
 	if (vtnet_tunable_int(sc, "mq_disable", vtnet_mq_disable))
 		features &= ~VIRTIO_NET_F_MQ;
 #else
 	features &= ~VIRTIO_NET_F_MQ;
 #endif
 
 	negotiated_features = virtio_negotiate_features(dev, features);
 
 	if (virtio_with_feature(dev, VIRTIO_NET_F_MTU)) {
 		uint16_t mtu;
 
 		mtu = virtio_read_dev_config_2(dev,
 		    offsetof(struct virtio_net_config, mtu));
 		if (mtu < VTNET_MIN_MTU /* || mtu > VTNET_MAX_MTU */) {
 			device_printf(dev, "Invalid MTU value: %d. "
 			    "MTU feature disabled.\n", mtu);
 			features &= ~VIRTIO_NET_F_MTU;
 			negotiated_features =
 			    virtio_negotiate_features(dev, features);
 		}
 	}
 
 	if (virtio_with_feature(dev, VIRTIO_NET_F_MQ)) {
 		uint16_t npairs;
 
 		npairs = virtio_read_dev_config_2(dev,
 		    offsetof(struct virtio_net_config, max_virtqueue_pairs));
 		if (npairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
 		    npairs > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX) {
 			device_printf(dev, "Invalid max_virtqueue_pairs value: "
 			    "%d. Multiqueue feature disabled.\n", npairs);
 			features &= ~VIRTIO_NET_F_MQ;
 			negotiated_features =
 			    virtio_negotiate_features(dev, features);
 		}
 	}
 
 	if (virtio_with_feature(dev, VTNET_LRO_FEATURES) &&
 	    virtio_with_feature(dev, VIRTIO_NET_F_MRG_RXBUF) == 0) {
 		/*
 		 * LRO without mergeable buffers requires special care. This
 		 * is not ideal because every receive buffer must be large
 		 * enough to hold the maximum TCP packet, the Ethernet header,
 		 * and the header. This requires up to 34 descriptors with
 		 * MCLBYTES clusters. If we do not have indirect descriptors,
 		 * LRO is disabled since the virtqueue will not contain very
 		 * many receive buffers.
 		 */
 		if (!virtio_with_feature(dev, VIRTIO_RING_F_INDIRECT_DESC)) {
 			device_printf(dev,
 			    "Host LRO disabled since both mergeable buffers "
 			    "and indirect descriptors were not negotiated\n");
 			features &= ~VTNET_LRO_FEATURES;
 			negotiated_features =
 			    virtio_negotiate_features(dev, features);
 		} else
 			sc->vtnet_flags |= VTNET_FLAG_LRO_NOMRG;
 	}
 
 	sc->vtnet_features = negotiated_features;
 	sc->vtnet_negotiated_features = negotiated_features;
 
 	virtio_finalize_features(dev);
 }
 
 static void
 vtnet_setup_features(struct vtnet_softc *sc)
 {
 	device_t dev;
 
 	dev = sc->vtnet_dev;
 
 	vtnet_negotiate_features(sc);
 
 	if (virtio_with_feature(dev, VIRTIO_F_VERSION_1))
 		sc->vtnet_flags |= VTNET_FLAG_MODERN;
 	if (virtio_with_feature(dev, VIRTIO_RING_F_INDIRECT_DESC))
 		sc->vtnet_flags |= VTNET_FLAG_INDIRECT;
 	if (virtio_with_feature(dev, VIRTIO_RING_F_EVENT_IDX))
 		sc->vtnet_flags |= VTNET_FLAG_EVENT_IDX;
 
 	if (virtio_with_feature(dev, VIRTIO_NET_F_MAC)) {
 		/* This feature should always be negotiated. */
 		sc->vtnet_flags |= VTNET_FLAG_MAC;
 	}
 
 	if (virtio_with_feature(dev, VIRTIO_NET_F_MTU)) {
 		sc->vtnet_max_mtu = virtio_read_dev_config_2(dev,
 		    offsetof(struct virtio_net_config, mtu));
 	} else
 		sc->vtnet_max_mtu = VTNET_MAX_MTU;
 
 	if (virtio_with_feature(dev, VIRTIO_NET_F_MRG_RXBUF)) {
 		sc->vtnet_flags |= VTNET_FLAG_MRG_RXBUFS;
 		sc->vtnet_hdr_size = sizeof(struct virtio_net_hdr_mrg_rxbuf);
 	} else if (vtnet_modern(sc)) {
 		/* This is identical to the mergeable header. */
 		sc->vtnet_hdr_size = sizeof(struct virtio_net_hdr_v1);
 	} else
 		sc->vtnet_hdr_size = sizeof(struct virtio_net_hdr);
 
 	if (vtnet_modern(sc) || sc->vtnet_flags & VTNET_FLAG_MRG_RXBUFS)
 		sc->vtnet_rx_nsegs = VTNET_RX_SEGS_HDR_INLINE;
 	else if (sc->vtnet_flags & VTNET_FLAG_LRO_NOMRG)
 		sc->vtnet_rx_nsegs = VTNET_RX_SEGS_LRO_NOMRG;
 	else
 		sc->vtnet_rx_nsegs = VTNET_RX_SEGS_HDR_SEPARATE;
 
 	/*
 	 * Favor "hardware" LRO if negotiated, but support software LRO as
 	 * a fallback; there is usually little benefit (or worse) with both.
 	 */
 	if (virtio_with_feature(dev, VIRTIO_NET_F_GUEST_TSO4) == 0 &&
 	    virtio_with_feature(dev, VIRTIO_NET_F_GUEST_TSO6) == 0)
 		sc->vtnet_flags |= VTNET_FLAG_SW_LRO;
 
 	if (virtio_with_feature(dev, VIRTIO_NET_F_GSO) ||
 	    virtio_with_feature(dev, VIRTIO_NET_F_HOST_TSO4) ||
 	    virtio_with_feature(dev, VIRTIO_NET_F_HOST_TSO6))
 		sc->vtnet_tx_nsegs = VTNET_TX_SEGS_MAX;
 	else
 		sc->vtnet_tx_nsegs = VTNET_TX_SEGS_MIN;
 
 	sc->vtnet_req_vq_pairs = 1;
 	sc->vtnet_max_vq_pairs = 1;
 
 	if (virtio_with_feature(dev, VIRTIO_NET_F_CTRL_VQ)) {
 		sc->vtnet_flags |= VTNET_FLAG_CTRL_VQ;
 
 		if (virtio_with_feature(dev, VIRTIO_NET_F_CTRL_RX))
 			sc->vtnet_flags |= VTNET_FLAG_CTRL_RX;
 		if (virtio_with_feature(dev, VIRTIO_NET_F_CTRL_VLAN))
 			sc->vtnet_flags |= VTNET_FLAG_VLAN_FILTER;
 		if (virtio_with_feature(dev, VIRTIO_NET_F_CTRL_MAC_ADDR))
 			sc->vtnet_flags |= VTNET_FLAG_CTRL_MAC;
 
 		if (virtio_with_feature(dev, VIRTIO_NET_F_MQ)) {
 			sc->vtnet_max_vq_pairs = virtio_read_dev_config_2(dev,
 			    offsetof(struct virtio_net_config,
 			    max_virtqueue_pairs));
 		}
 	}
 
 	if (sc->vtnet_max_vq_pairs > 1) {
 		int req;
 
 		/*
 		 * Limit the maximum number of requested queue pairs to the
 		 * number of CPUs and the configured maximum.
 		 */
 		req = vtnet_tunable_int(sc, "mq_max_pairs", vtnet_mq_max_pairs);
 		if (req < 0)
 			req = 1;
 		if (req == 0)
 			req = mp_ncpus;
 		if (req > sc->vtnet_max_vq_pairs)
 			req = sc->vtnet_max_vq_pairs;
 		if (req > mp_ncpus)
 			req = mp_ncpus;
 		if (req > 1) {
 			sc->vtnet_req_vq_pairs = req;
 			sc->vtnet_flags |= VTNET_FLAG_MQ;
 		}
 	}
 }
 
 static int
 vtnet_init_rxq(struct vtnet_softc *sc, int id)
 {
 	struct vtnet_rxq *rxq;
 
 	rxq = &sc->vtnet_rxqs[id];
 
 	snprintf(rxq->vtnrx_name, sizeof(rxq->vtnrx_name), "%s-rx%d",
 	    device_get_nameunit(sc->vtnet_dev), id);
 	mtx_init(&rxq->vtnrx_mtx, rxq->vtnrx_name, NULL, MTX_DEF);
 
 	rxq->vtnrx_sc = sc;
 	rxq->vtnrx_id = id;
 
 	rxq->vtnrx_sg = sglist_alloc(sc->vtnet_rx_nsegs, M_NOWAIT);
 	if (rxq->vtnrx_sg == NULL)
 		return (ENOMEM);
 
 #if defined(INET) || defined(INET6)
 	if (vtnet_software_lro(sc)) {
 		if (tcp_lro_init_args(&rxq->vtnrx_lro, sc->vtnet_ifp,
 		    sc->vtnet_lro_entry_count, sc->vtnet_lro_mbufq_depth) != 0)
 			return (ENOMEM);
 	}
 #endif
 
 	NET_TASK_INIT(&rxq->vtnrx_intrtask, 0, vtnet_rxq_tq_intr, rxq);
 	rxq->vtnrx_tq = taskqueue_create(rxq->vtnrx_name, M_NOWAIT,
 	    taskqueue_thread_enqueue, &rxq->vtnrx_tq);
 
 	return (rxq->vtnrx_tq == NULL ? ENOMEM : 0);
 }
 
 static int
 vtnet_init_txq(struct vtnet_softc *sc, int id)
 {
 	struct vtnet_txq *txq;
 
 	txq = &sc->vtnet_txqs[id];
 
 	snprintf(txq->vtntx_name, sizeof(txq->vtntx_name), "%s-tx%d",
 	    device_get_nameunit(sc->vtnet_dev), id);
 	mtx_init(&txq->vtntx_mtx, txq->vtntx_name, NULL, MTX_DEF);
 
 	txq->vtntx_sc = sc;
 	txq->vtntx_id = id;
 
 	txq->vtntx_sg = sglist_alloc(sc->vtnet_tx_nsegs, M_NOWAIT);
 	if (txq->vtntx_sg == NULL)
 		return (ENOMEM);
 
 #ifndef VTNET_LEGACY_TX
 	txq->vtntx_br = buf_ring_alloc(VTNET_DEFAULT_BUFRING_SIZE, M_DEVBUF,
 	    M_NOWAIT, &txq->vtntx_mtx);
 	if (txq->vtntx_br == NULL)
 		return (ENOMEM);
 
 	TASK_INIT(&txq->vtntx_defrtask, 0, vtnet_txq_tq_deferred, txq);
 #endif
 	TASK_INIT(&txq->vtntx_intrtask, 0, vtnet_txq_tq_intr, txq);
 	txq->vtntx_tq = taskqueue_create(txq->vtntx_name, M_NOWAIT,
 	    taskqueue_thread_enqueue, &txq->vtntx_tq);
 	if (txq->vtntx_tq == NULL)
 		return (ENOMEM);
 
 	return (0);
 }
 
 static int
 vtnet_alloc_rxtx_queues(struct vtnet_softc *sc)
 {
 	int i, npairs, error;
 
 	npairs = sc->vtnet_max_vq_pairs;
 
 	sc->vtnet_rxqs = malloc(sizeof(struct vtnet_rxq) * npairs, M_DEVBUF,
 	    M_NOWAIT | M_ZERO);
 	sc->vtnet_txqs = malloc(sizeof(struct vtnet_txq) * npairs, M_DEVBUF,
 	    M_NOWAIT | M_ZERO);
 	if (sc->vtnet_rxqs == NULL || sc->vtnet_txqs == NULL)
 		return (ENOMEM);
 
 	for (i = 0; i < npairs; i++) {
 		error = vtnet_init_rxq(sc, i);
 		if (error)
 			return (error);
 		error = vtnet_init_txq(sc, i);
 		if (error)
 			return (error);
 	}
 
 	vtnet_set_rx_process_limit(sc);
 	vtnet_setup_queue_sysctl(sc);
 
 	return (0);
 }
 
 static void
 vtnet_destroy_rxq(struct vtnet_rxq *rxq)
 {
 
 	rxq->vtnrx_sc = NULL;
 	rxq->vtnrx_id = -1;
 
 #if defined(INET) || defined(INET6)
 	tcp_lro_free(&rxq->vtnrx_lro);
 #endif
 
 	if (rxq->vtnrx_sg != NULL) {
 		sglist_free(rxq->vtnrx_sg);
 		rxq->vtnrx_sg = NULL;
 	}
 
 	if (mtx_initialized(&rxq->vtnrx_mtx) != 0)
 		mtx_destroy(&rxq->vtnrx_mtx);
 }
 
 static void
 vtnet_destroy_txq(struct vtnet_txq *txq)
 {
 
 	txq->vtntx_sc = NULL;
 	txq->vtntx_id = -1;
 
 	if (txq->vtntx_sg != NULL) {
 		sglist_free(txq->vtntx_sg);
 		txq->vtntx_sg = NULL;
 	}
 
 #ifndef VTNET_LEGACY_TX
 	if (txq->vtntx_br != NULL) {
 		buf_ring_free(txq->vtntx_br, M_DEVBUF);
 		txq->vtntx_br = NULL;
 	}
 #endif
 
 	if (mtx_initialized(&txq->vtntx_mtx) != 0)
 		mtx_destroy(&txq->vtntx_mtx);
 }
 
 static void
 vtnet_free_rxtx_queues(struct vtnet_softc *sc)
 {
 	int i;
 
 	if (sc->vtnet_rxqs != NULL) {
 		for (i = 0; i < sc->vtnet_max_vq_pairs; i++)
 			vtnet_destroy_rxq(&sc->vtnet_rxqs[i]);
 		free(sc->vtnet_rxqs, M_DEVBUF);
 		sc->vtnet_rxqs = NULL;
 	}
 
 	if (sc->vtnet_txqs != NULL) {
 		for (i = 0; i < sc->vtnet_max_vq_pairs; i++)
 			vtnet_destroy_txq(&sc->vtnet_txqs[i]);
 		free(sc->vtnet_txqs, M_DEVBUF);
 		sc->vtnet_txqs = NULL;
 	}
 }
 
 static int
 vtnet_alloc_rx_filters(struct vtnet_softc *sc)
 {
 
 	if (sc->vtnet_flags & VTNET_FLAG_CTRL_RX) {
 		sc->vtnet_mac_filter = malloc(sizeof(struct vtnet_mac_filter),
 		    M_DEVBUF, M_NOWAIT | M_ZERO);
 		if (sc->vtnet_mac_filter == NULL)
 			return (ENOMEM);
 	}
 
 	if (sc->vtnet_flags & VTNET_FLAG_VLAN_FILTER) {
 		sc->vtnet_vlan_filter = malloc(sizeof(uint32_t) *
 		    VTNET_VLAN_FILTER_NWORDS, M_DEVBUF, M_NOWAIT | M_ZERO);
 		if (sc->vtnet_vlan_filter == NULL)
 			return (ENOMEM);
 	}
 
 	return (0);
 }
 
 static void
 vtnet_free_rx_filters(struct vtnet_softc *sc)
 {
 
 	if (sc->vtnet_mac_filter != NULL) {
 		free(sc->vtnet_mac_filter, M_DEVBUF);
 		sc->vtnet_mac_filter = NULL;
 	}
 
 	if (sc->vtnet_vlan_filter != NULL) {
 		free(sc->vtnet_vlan_filter, M_DEVBUF);
 		sc->vtnet_vlan_filter = NULL;
 	}
 }
 
 static int
 vtnet_alloc_virtqueues(struct vtnet_softc *sc)
 {
 	device_t dev;
 	struct vq_alloc_info *info;
 	struct vtnet_rxq *rxq;
 	struct vtnet_txq *txq;
 	int i, idx, flags, nvqs, error;
 
 	dev = sc->vtnet_dev;
 	flags = 0;
 
 	nvqs = sc->vtnet_max_vq_pairs * 2;
 	if (sc->vtnet_flags & VTNET_FLAG_CTRL_VQ)
 		nvqs++;
 
 	info = malloc(sizeof(struct vq_alloc_info) * nvqs, M_TEMP, M_NOWAIT);
 	if (info == NULL)
 		return (ENOMEM);
 
 	for (i = 0, idx = 0; i < sc->vtnet_req_vq_pairs; i++, idx += 2) {
 		rxq = &sc->vtnet_rxqs[i];
 		VQ_ALLOC_INFO_INIT(&info[idx], sc->vtnet_rx_nsegs,
 		    vtnet_rx_vq_intr, rxq, &rxq->vtnrx_vq,
 		    "%s-rx%d", device_get_nameunit(dev), rxq->vtnrx_id);
 
 		txq = &sc->vtnet_txqs[i];
 		VQ_ALLOC_INFO_INIT(&info[idx+1], sc->vtnet_tx_nsegs,
 		    vtnet_tx_vq_intr, txq, &txq->vtntx_vq,
 		    "%s-tx%d", device_get_nameunit(dev), txq->vtntx_id);
 	}
 
 	/* These queues will not be used so allocate the minimum resources. */
 	for (/**/; i < sc->vtnet_max_vq_pairs; i++, idx += 2) {
 		rxq = &sc->vtnet_rxqs[i];
 		VQ_ALLOC_INFO_INIT(&info[idx], 0, NULL, rxq, &rxq->vtnrx_vq,
 		    "%s-rx%d", device_get_nameunit(dev), rxq->vtnrx_id);
 
 		txq = &sc->vtnet_txqs[i];
 		VQ_ALLOC_INFO_INIT(&info[idx+1], 0, NULL, txq, &txq->vtntx_vq,
 		    "%s-tx%d", device_get_nameunit(dev), txq->vtntx_id);
 	}
 
 	if (sc->vtnet_flags & VTNET_FLAG_CTRL_VQ) {
 		VQ_ALLOC_INFO_INIT(&info[idx], 0, NULL, NULL,
 		    &sc->vtnet_ctrl_vq, "%s ctrl", device_get_nameunit(dev));
 	}
 
 	/*
 	 * TODO: Enable interrupt binding if this is multiqueue. This will
 	 * only matter when per-virtqueue MSIX is available.
 	 */
 	if (sc->vtnet_flags & VTNET_FLAG_MQ)
 		flags |= 0;
 
 	error = virtio_alloc_virtqueues(dev, flags, nvqs, info);
 	free(info, M_TEMP);
 
 	return (error);
 }
 
 static int
 vtnet_alloc_interface(struct vtnet_softc *sc)
 {
 	device_t dev;
 	struct ifnet *ifp;
 
 	dev = sc->vtnet_dev;
 
 	ifp = if_alloc(IFT_ETHER);
 	if (ifp == NULL)
 		return (ENOMEM);
 
 	sc->vtnet_ifp = ifp;
 	ifp->if_softc = sc;
 	if_initname(ifp, device_get_name(dev), device_get_unit(dev));
 
 	return (0);
 }
 
 static int
 vtnet_setup_interface(struct vtnet_softc *sc)
 {
 	device_t dev;
 	struct pfil_head_args pa;
 	struct ifnet *ifp;
 
 	dev = sc->vtnet_dev;
 	ifp = sc->vtnet_ifp;
 
 	ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST |
 	    IFF_KNOWSEPOCH;
 	ifp->if_baudrate = IF_Gbps(10);
 	ifp->if_init = vtnet_init;
 	ifp->if_ioctl = vtnet_ioctl;
 	ifp->if_get_counter = vtnet_get_counter;
 #ifndef VTNET_LEGACY_TX
 	ifp->if_transmit = vtnet_txq_mq_start;
 	ifp->if_qflush = vtnet_qflush;
 #else
 	struct virtqueue *vq = sc->vtnet_txqs[0].vtntx_vq;
 	ifp->if_start = vtnet_start;
 	IFQ_SET_MAXLEN(&ifp->if_snd, virtqueue_size(vq) - 1);
 	ifp->if_snd.ifq_drv_maxlen = virtqueue_size(vq) - 1;
 	IFQ_SET_READY(&ifp->if_snd);
 #endif
 
 	vtnet_get_macaddr(sc);
 
 	if (virtio_with_feature(dev, VIRTIO_NET_F_STATUS))
 		ifp->if_capabilities |= IFCAP_LINKSTATE;
 
 	ifmedia_init(&sc->vtnet_media, 0, vtnet_ifmedia_upd, vtnet_ifmedia_sts);
 	ifmedia_add(&sc->vtnet_media, IFM_ETHER | IFM_AUTO, 0, NULL);
 	ifmedia_set(&sc->vtnet_media, IFM_ETHER | IFM_AUTO);
 
 	if (virtio_with_feature(dev, VIRTIO_NET_F_CSUM)) {
 		int gso;
 
 		ifp->if_capabilities |= IFCAP_TXCSUM | IFCAP_TXCSUM_IPV6;
 
 		gso = virtio_with_feature(dev, VIRTIO_NET_F_GSO);
 		if (gso || virtio_with_feature(dev, VIRTIO_NET_F_HOST_TSO4))
 			ifp->if_capabilities |= IFCAP_TSO4;
 		if (gso || virtio_with_feature(dev, VIRTIO_NET_F_HOST_TSO6))
 			ifp->if_capabilities |= IFCAP_TSO6;
 		if (gso || virtio_with_feature(dev, VIRTIO_NET_F_HOST_ECN))
 			sc->vtnet_flags |= VTNET_FLAG_TSO_ECN;
 
 		if (ifp->if_capabilities & (IFCAP_TSO4 | IFCAP_TSO6)) {
 			int tso_maxlen;
 
 			ifp->if_capabilities |= IFCAP_VLAN_HWTSO;
 
 			tso_maxlen = vtnet_tunable_int(sc, "tso_maxlen",
 			    vtnet_tso_maxlen);
 			ifp->if_hw_tsomax = tso_maxlen -
 			    (ETHER_HDR_LEN + ETHER_VLAN_ENCAP_LEN);
 			ifp->if_hw_tsomaxsegcount = sc->vtnet_tx_nsegs - 1;
 			ifp->if_hw_tsomaxsegsize = PAGE_SIZE;
 		}
 	}
 
 	if (virtio_with_feature(dev, VIRTIO_NET_F_GUEST_CSUM)) {
 		ifp->if_capabilities |= IFCAP_RXCSUM;
 #ifdef notyet
 		/* BMV: Rx checksums not distinguished between IPv4 and IPv6. */
 		ifp->if_capabilities |= IFCAP_RXCSUM_IPV6;
 #endif
 
 		if (vtnet_tunable_int(sc, "fixup_needs_csum",
 		    vtnet_fixup_needs_csum) != 0)
 			sc->vtnet_flags |= VTNET_FLAG_FIXUP_NEEDS_CSUM;
 
 		/* Support either "hardware" or software LRO. */
 		ifp->if_capabilities |= IFCAP_LRO;
 	}
 
 	if (ifp->if_capabilities & (IFCAP_HWCSUM | IFCAP_HWCSUM_IPV6)) {
 		/*
 		 * VirtIO does not support VLAN tagging, but we can fake
 		 * it by inserting and removing the 802.1Q header during
 		 * transmit and receive. We are then able to do checksum
 		 * offloading of VLAN frames.
 		 */
 		ifp->if_capabilities |=
 		    IFCAP_VLAN_HWTAGGING | IFCAP_VLAN_HWCSUM;
 	}
 
 	if (sc->vtnet_max_mtu >= ETHERMTU_JUMBO)
 		ifp->if_capabilities |= IFCAP_JUMBO_MTU;
 	ifp->if_capabilities |= IFCAP_VLAN_MTU;
 
 	/*
 	 * Capabilities after here are not enabled by default.
 	 */
 	ifp->if_capenable = ifp->if_capabilities;
 
 	if (sc->vtnet_flags & VTNET_FLAG_VLAN_FILTER) {
 		ifp->if_capabilities |= IFCAP_VLAN_HWFILTER;
 
 		sc->vtnet_vlan_attach = EVENTHANDLER_REGISTER(vlan_config,
 		    vtnet_register_vlan, sc, EVENTHANDLER_PRI_FIRST);
 		sc->vtnet_vlan_detach = EVENTHANDLER_REGISTER(vlan_unconfig,
 		    vtnet_unregister_vlan, sc, EVENTHANDLER_PRI_FIRST);
 	}
 
 	ether_ifattach(ifp, sc->vtnet_hwaddr);
 
 	/* Tell the upper layer(s) we support long frames. */
 	ifp->if_hdrlen = sizeof(struct ether_vlan_header);
 
 	DEBUGNET_SET(ifp, vtnet);
 
 	pa.pa_version = PFIL_VERSION;
 	pa.pa_flags = PFIL_IN;
 	pa.pa_type = PFIL_TYPE_ETHERNET;
 	pa.pa_headname = ifp->if_xname;
 	sc->vtnet_pfil = pfil_head_register(&pa);
 
 	return (0);
 }
 
 static int
 vtnet_rx_cluster_size(struct vtnet_softc *sc, int mtu)
 {
 	int framesz;
 
 	if (sc->vtnet_flags & VTNET_FLAG_MRG_RXBUFS)
 		return (MJUMPAGESIZE);
 	else if (sc->vtnet_flags & VTNET_FLAG_LRO_NOMRG)
 		return (MCLBYTES);
 
 	/*
 	 * Try to scale the receive mbuf cluster size from the MTU. We
 	 * could also use the VQ size to influence the selected size,
 	 * but that would only matter for very small queues.
 	 */
 	if (vtnet_modern(sc)) {
 		MPASS(sc->vtnet_hdr_size == sizeof(struct virtio_net_hdr_v1));
 		framesz = sizeof(struct virtio_net_hdr_v1);
 	} else
 		framesz = sizeof(struct vtnet_rx_header);
 	framesz += sizeof(struct ether_vlan_header) + mtu;
 
 	if (framesz <= MCLBYTES)
 		return (MCLBYTES);
 	else if (framesz <= MJUMPAGESIZE)
 		return (MJUMPAGESIZE);
 	else if (framesz <= MJUM9BYTES)
 		return (MJUM9BYTES);
 
 	/* Sane default; avoid 16KB clusters. */
 	return (MCLBYTES);
 }
 
 static int
 vtnet_ioctl_mtu(struct vtnet_softc *sc, int mtu)
 {
 	struct ifnet *ifp;
 	int clustersz;
 
 	ifp = sc->vtnet_ifp;
 	VTNET_CORE_LOCK_ASSERT(sc);
 
 	if (ifp->if_mtu == mtu)
 		return (0);
 	else if (mtu < ETHERMIN || mtu > sc->vtnet_max_mtu)
 		return (EINVAL);
 
 	ifp->if_mtu = mtu;
 	clustersz = vtnet_rx_cluster_size(sc, mtu);
 
 	if (clustersz != sc->vtnet_rx_clustersz &&
 	    ifp->if_drv_flags & IFF_DRV_RUNNING) {
 		ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
 		vtnet_init_locked(sc, 0);
 	}
 
 	return (0);
 }
 
 static int
 vtnet_ioctl_ifflags(struct vtnet_softc *sc)
 {
 	struct ifnet *ifp;
 	int drv_running;
 
 	ifp = sc->vtnet_ifp;
 	drv_running = (ifp->if_drv_flags & IFF_DRV_RUNNING) != 0;
 
 	VTNET_CORE_LOCK_ASSERT(sc);
 
 	if ((ifp->if_flags & IFF_UP) == 0) {
 		if (drv_running)
 			vtnet_stop(sc);
 		goto out;
 	}
 
 	if (!drv_running) {
 		vtnet_init_locked(sc, 0);
 		goto out;
 	}
 
 	if ((ifp->if_flags ^ sc->vtnet_if_flags) &
 	    (IFF_PROMISC | IFF_ALLMULTI)) {
 		if ((sc->vtnet_flags & VTNET_FLAG_CTRL_RX) == 0)
 			return (ENOTSUP);
 		vtnet_rx_filter(sc);
 	}
 
 out:
 	sc->vtnet_if_flags = ifp->if_flags;
 	return (0);
 }
 
 static int
 vtnet_ioctl_multi(struct vtnet_softc *sc)
 {
 	struct ifnet *ifp;
 
 	ifp = sc->vtnet_ifp;
 
 	VTNET_CORE_LOCK_ASSERT(sc);
 
 	if (sc->vtnet_flags & VTNET_FLAG_CTRL_RX &&
 	    ifp->if_drv_flags & IFF_DRV_RUNNING)
 		vtnet_rx_filter_mac(sc);
 
 	return (0);
 }
 
 static int
 vtnet_ioctl_ifcap(struct vtnet_softc *sc, struct ifreq *ifr)
 {
 	struct ifnet *ifp;
 	int mask, reinit, update;
 
 	ifp = sc->vtnet_ifp;
 	mask = (ifr->ifr_reqcap & ifp->if_capabilities) ^ ifp->if_capenable;
 	reinit = update = 0;
 
 	VTNET_CORE_LOCK_ASSERT(sc);
 
 	if (mask & IFCAP_TXCSUM)
 		ifp->if_capenable ^= IFCAP_TXCSUM;
 	if (mask & IFCAP_TXCSUM_IPV6)
 		ifp->if_capenable ^= IFCAP_TXCSUM_IPV6;
 	if (mask & IFCAP_TSO4)
 		ifp->if_capenable ^= IFCAP_TSO4;
 	if (mask & IFCAP_TSO6)
 		ifp->if_capenable ^= IFCAP_TSO6;
 
 	if (mask & (IFCAP_RXCSUM | IFCAP_RXCSUM_IPV6 | IFCAP_LRO)) {
 		/*
 		 * These Rx features require the negotiated features to
 		 * be updated. Avoid a full reinit if possible.
 		 */
 		if (sc->vtnet_features & VIRTIO_NET_F_CTRL_GUEST_OFFLOADS)
 			update = 1;
 		else
 			reinit = 1;
 
 		/* BMV: Avoid needless renegotiation for just software LRO. */
 		if ((mask & (IFCAP_RXCSUM | IFCAP_RXCSUM_IPV6 | IFCAP_LRO)) ==
 		    IFCAP_LRO && vtnet_software_lro(sc))
 			reinit = update = 0;
 
 		if (mask & IFCAP_RXCSUM)
 			ifp->if_capenable ^= IFCAP_RXCSUM;
 		if (mask & IFCAP_RXCSUM_IPV6)
 			ifp->if_capenable ^= IFCAP_RXCSUM_IPV6;
 		if (mask & IFCAP_LRO)
 			ifp->if_capenable ^= IFCAP_LRO;
 
 		/*
 		 * VirtIO does not distinguish between IPv4 and IPv6 checksums
 		 * so treat them as a pair. Guest TSO (LRO) requires receive
 		 * checksums.
 		 */
 		if (ifp->if_capenable & (IFCAP_RXCSUM | IFCAP_RXCSUM_IPV6)) {
 			ifp->if_capenable |= IFCAP_RXCSUM;
 #ifdef notyet
 			ifp->if_capenable |= IFCAP_RXCSUM_IPV6;
 #endif
 		} else
 			ifp->if_capenable &=
 			    ~(IFCAP_RXCSUM | IFCAP_RXCSUM_IPV6 | IFCAP_LRO);
 	}
 
 	if (mask & IFCAP_VLAN_HWFILTER) {
 		/* These Rx features require renegotiation. */
 		reinit = 1;
 
 		if (mask & IFCAP_VLAN_HWFILTER)
 			ifp->if_capenable ^= IFCAP_VLAN_HWFILTER;
 	}
 
 	if (mask & IFCAP_VLAN_HWTSO)
 		ifp->if_capenable ^= IFCAP_VLAN_HWTSO;
 	if (mask & IFCAP_VLAN_HWTAGGING)
 		ifp->if_capenable ^= IFCAP_VLAN_HWTAGGING;
 
 	if (ifp->if_drv_flags & IFF_DRV_RUNNING) {
 		if (reinit) {
 			ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
 			vtnet_init_locked(sc, 0);
 		} else if (update)
 			vtnet_update_rx_offloads(sc);
 	}
 
 	return (0);
 }
 
 static int
 vtnet_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
 {
 	struct vtnet_softc *sc;
 	struct ifreq *ifr;
 	int error;
 
 	sc = ifp->if_softc;
 	ifr = (struct ifreq *) data;
 	error = 0;
 
 	switch (cmd) {
 	case SIOCSIFMTU:
 		VTNET_CORE_LOCK(sc);
 		error = vtnet_ioctl_mtu(sc, ifr->ifr_mtu);
 		VTNET_CORE_UNLOCK(sc);
 		break;
 
 	case SIOCSIFFLAGS:
 		VTNET_CORE_LOCK(sc);
 		error = vtnet_ioctl_ifflags(sc);
 		VTNET_CORE_UNLOCK(sc);
 		break;
 
 	case SIOCADDMULTI:
 	case SIOCDELMULTI:
 		VTNET_CORE_LOCK(sc);
 		error = vtnet_ioctl_multi(sc);
 		VTNET_CORE_UNLOCK(sc);
 		break;
 
 	case SIOCSIFMEDIA:
 	case SIOCGIFMEDIA:
 		error = ifmedia_ioctl(ifp, ifr, &sc->vtnet_media, cmd);
 		break;
 
 	case SIOCSIFCAP:
 		VTNET_CORE_LOCK(sc);
 		error = vtnet_ioctl_ifcap(sc, ifr);
 		VTNET_CORE_UNLOCK(sc);
 		VLAN_CAPABILITIES(ifp);
 		break;
 
 	default:
 		error = ether_ioctl(ifp, cmd, data);
 		break;
 	}
 
 	VTNET_CORE_LOCK_ASSERT_NOTOWNED(sc);
 
 	return (error);
 }
 
 static int
 vtnet_rxq_populate(struct vtnet_rxq *rxq)
 {
 	struct virtqueue *vq;
 	int nbufs, error;
 
 #ifdef DEV_NETMAP
 	error = vtnet_netmap_rxq_populate(rxq);
 	if (error >= 0)
 		return (error);
 #endif  /* DEV_NETMAP */
 
 	vq = rxq->vtnrx_vq;
 	error = ENOSPC;
 
 	for (nbufs = 0; !virtqueue_full(vq); nbufs++) {
 		error = vtnet_rxq_new_buf(rxq);
 		if (error)
 			break;
 	}
 
 	if (nbufs > 0) {
 		virtqueue_notify(vq);
 		/*
 		 * EMSGSIZE signifies the virtqueue did not have enough
 		 * entries available to hold the last mbuf. This is not
 		 * an error.
 		 */
 		if (error == EMSGSIZE)
 			error = 0;
 	}
 
 	return (error);
 }
 
 static void
 vtnet_rxq_free_mbufs(struct vtnet_rxq *rxq)
 {
 	struct virtqueue *vq;
 	struct mbuf *m;
 	int last;
 #ifdef DEV_NETMAP
 	struct netmap_kring *kring = netmap_kring_on(NA(rxq->vtnrx_sc->vtnet_ifp),
 							rxq->vtnrx_id, NR_RX);
 #else  /* !DEV_NETMAP */
 	void *kring = NULL;
 #endif /* !DEV_NETMAP */
 
 	vq = rxq->vtnrx_vq;
 	last = 0;
 
 	while ((m = virtqueue_drain(vq, &last)) != NULL) {
 		if (kring == NULL)
 			m_freem(m);
 	}
 
 	KASSERT(virtqueue_empty(vq),
 	    ("%s: mbufs remaining in rx queue %p", __func__, rxq));
 }
 
 static struct mbuf *
 vtnet_rx_alloc_buf(struct vtnet_softc *sc, int nbufs, struct mbuf **m_tailp)
 {
 	struct mbuf *m_head, *m_tail, *m;
 	int i, size;
 
 	m_head = NULL;
 	size = sc->vtnet_rx_clustersz;
 
 	KASSERT(nbufs == 1 || sc->vtnet_flags & VTNET_FLAG_LRO_NOMRG,
 	    ("%s: mbuf %d chain requested without LRO_NOMRG", __func__, nbufs));
 
 	for (i = 0; i < nbufs; i++) {
 		m = m_getjcl(M_NOWAIT, MT_DATA, i == 0 ? M_PKTHDR : 0, size);
 		if (m == NULL) {
 			sc->vtnet_stats.mbuf_alloc_failed++;
 			m_freem(m_head);
 			return (NULL);
 		}
 
 		m->m_len = size;
 		if (m_head != NULL) {
 			m_tail->m_next = m;
 			m_tail = m;
 		} else
 			m_head = m_tail = m;
 	}
 
 	if (m_tailp != NULL)
 		*m_tailp = m_tail;
 
 	return (m_head);
 }
 
 /*
  * Slow path for when LRO without mergeable buffers is negotiated.
  */
 static int
 vtnet_rxq_replace_lro_nomrg_buf(struct vtnet_rxq *rxq, struct mbuf *m0,
     int len0)
 {
 	struct vtnet_softc *sc;
 	struct mbuf *m, *m_prev, *m_new, *m_tail;
 	int len, clustersz, nreplace, error;
 
 	sc = rxq->vtnrx_sc;
 	clustersz = sc->vtnet_rx_clustersz;
 
 	m_prev = NULL;
 	m_tail = NULL;
 	nreplace = 0;
 
 	m = m0;
 	len = len0;
 
 	/*
 	 * Since these mbuf chains are so large, avoid allocating a complete
 	 * replacement when the received frame did not consume the entire
 	 * chain. Unused mbufs are moved to the tail of the replacement mbuf.
 	 */
 	while (len > 0) {
 		if (m == NULL) {
 			sc->vtnet_stats.rx_frame_too_large++;
 			return (EMSGSIZE);
 		}
 
 		/*
 		 * Every mbuf should have the expected cluster size since that
 		 * is also used to allocate the replacements.
 		 */
 		KASSERT(m->m_len == clustersz,
 		    ("%s: mbuf size %d not expected cluster size %d", __func__,
 		    m->m_len, clustersz));
 
 		m->m_len = MIN(m->m_len, len);
 		len -= m->m_len;
 
 		m_prev = m;
 		m = m->m_next;
 		nreplace++;
 	}
 
 	KASSERT(nreplace > 0 && nreplace <= sc->vtnet_rx_nmbufs,
 	    ("%s: invalid replacement mbuf count %d max %d", __func__,
 	    nreplace, sc->vtnet_rx_nmbufs));
 
 	m_new = vtnet_rx_alloc_buf(sc, nreplace, &m_tail);
 	if (m_new == NULL) {
 		m_prev->m_len = clustersz;
 		return (ENOBUFS);
 	}
 
 	/*
 	 * Move any unused mbufs from the received mbuf chain onto the
 	 * end of the replacement chain.
 	 */
 	if (m_prev->m_next != NULL) {
 		m_tail->m_next = m_prev->m_next;
 		m_prev->m_next = NULL;
 	}
 
 	error = vtnet_rxq_enqueue_buf(rxq, m_new);
 	if (error) {
 		/*
 		 * The replacement is suppose to be an copy of the one
 		 * dequeued so this is a very unexpected error.
 		 *
 		 * Restore the m0 chain to the original state if it was
 		 * modified so we can then discard it.
 		 */
 		if (m_tail->m_next != NULL) {
 			m_prev->m_next = m_tail->m_next;
 			m_tail->m_next = NULL;
 		}
 		m_prev->m_len = clustersz;
 		sc->vtnet_stats.rx_enq_replacement_failed++;
 		m_freem(m_new);
 	}
 
 	return (error);
 }
 
 static int
 vtnet_rxq_replace_buf(struct vtnet_rxq *rxq, struct mbuf *m, int len)
 {
 	struct vtnet_softc *sc;
 	struct mbuf *m_new;
 	int error;
 
 	sc = rxq->vtnrx_sc;
 
 	if (sc->vtnet_flags & VTNET_FLAG_LRO_NOMRG)
 		return (vtnet_rxq_replace_lro_nomrg_buf(rxq, m, len));
 
 	MPASS(m->m_next == NULL);
 	if (m->m_len < len)
 		return (EMSGSIZE);
 
 	m_new = vtnet_rx_alloc_buf(sc, 1, NULL);
 	if (m_new == NULL)
 		return (ENOBUFS);
 
 	error = vtnet_rxq_enqueue_buf(rxq, m_new);
 	if (error) {
 		sc->vtnet_stats.rx_enq_replacement_failed++;
 		m_freem(m_new);
 	} else
 		m->m_len = len;
 
 	return (error);
 }
 
 static int
 vtnet_rxq_enqueue_buf(struct vtnet_rxq *rxq, struct mbuf *m)
 {
 	struct vtnet_softc *sc;
 	struct sglist *sg;
 	int header_inlined, error;
 
 	sc = rxq->vtnrx_sc;
 	sg = rxq->vtnrx_sg;
 
 	KASSERT(m->m_next == NULL || sc->vtnet_flags & VTNET_FLAG_LRO_NOMRG,
 	    ("%s: mbuf chain without LRO_NOMRG", __func__));
 	VTNET_RXQ_LOCK_ASSERT(rxq);
 
 	sglist_reset(sg);
 	header_inlined = vtnet_modern(sc) ||
 	    (sc->vtnet_flags & VTNET_FLAG_MRG_RXBUFS) != 0; /* TODO: ANY_LAYOUT */
 
 	if (header_inlined)
 		error = sglist_append_mbuf(sg, m);
 	else {
 		struct vtnet_rx_header *rxhdr =
 		    mtod(m, struct vtnet_rx_header *);
 		MPASS(sc->vtnet_hdr_size == sizeof(struct virtio_net_hdr));
 
 		/* Append the header and remaining mbuf data. */
 		error = sglist_append(sg, &rxhdr->vrh_hdr, sc->vtnet_hdr_size);
 		if (error)
 			return (error);
 		error = sglist_append(sg, &rxhdr[1],
 		    m->m_len - sizeof(struct vtnet_rx_header));
 		if (error)
 			return (error);
 
 		if (m->m_next != NULL)
 			error = sglist_append_mbuf(sg, m->m_next);
 	}
 
 	if (error)
 		return (error);
 
 	return (virtqueue_enqueue(rxq->vtnrx_vq, m, sg, 0, sg->sg_nseg));
 }
 
 static int
 vtnet_rxq_new_buf(struct vtnet_rxq *rxq)
 {
 	struct vtnet_softc *sc;
 	struct mbuf *m;
 	int error;
 
 	sc = rxq->vtnrx_sc;
 
 	m = vtnet_rx_alloc_buf(sc, sc->vtnet_rx_nmbufs, NULL);
 	if (m == NULL)
 		return (ENOBUFS);
 
 	error = vtnet_rxq_enqueue_buf(rxq, m);
 	if (error)
 		m_freem(m);
 
 	return (error);
 }
 
 static int
 vtnet_rxq_csum_needs_csum(struct vtnet_rxq *rxq, struct mbuf *m, uint16_t etype,
     int hoff, struct virtio_net_hdr *hdr)
 {
 	struct vtnet_softc *sc;
 	int error;
 
 	sc = rxq->vtnrx_sc;
 
 	/*
 	 * NEEDS_CSUM corresponds to Linux's CHECKSUM_PARTIAL, but FreeBSD does
 	 * not have an analogous CSUM flag. The checksum has been validated,
 	 * but is incomplete (TCP/UDP pseudo header).
 	 *
 	 * The packet is likely from another VM on the same host that itself
 	 * performed checksum offloading so Tx/Rx is basically a memcpy and
 	 * the checksum has little value.
 	 *
 	 * Default to receiving the packet as-is for performance reasons, but
 	 * this can cause issues if the packet is to be forwarded because it
 	 * does not contain a valid checksum. This patch may be helpful:
 	 * https://reviews.freebsd.org/D6611. In the meantime, have the driver
 	 * compute the checksum if requested.
 	 *
 	 * BMV: Need to add an CSUM_PARTIAL flag?
 	 */
 	if ((sc->vtnet_flags & VTNET_FLAG_FIXUP_NEEDS_CSUM) == 0) {
 		error = vtnet_rxq_csum_data_valid(rxq, m, etype, hoff, hdr);
 		return (error);
 	}
 
 	/*
 	 * Compute the checksum in the driver so the packet will contain a
 	 * valid checksum. The checksum is at csum_offset from csum_start.
 	 */
 	switch (etype) {
 #if defined(INET) || defined(INET6)
 	case ETHERTYPE_IP:
 	case ETHERTYPE_IPV6: {
 		int csum_off, csum_end;
 		uint16_t csum;
 
 		csum_off = hdr->csum_start + hdr->csum_offset;
 		csum_end = csum_off + sizeof(uint16_t);
 
 		/* Assume checksum will be in the first mbuf. */
 		if (m->m_len < csum_end || m->m_pkthdr.len < csum_end)
 			return (1);
 
 		/*
 		 * Like in_delayed_cksum()/in6_delayed_cksum(), compute the
 		 * checksum and write it at the specified offset. We could
 		 * try to verify the packet: csum_start should probably
 		 * correspond to the start of the TCP/UDP header.
 		 *
 		 * BMV: Need to properly handle UDP with zero checksum. Is
 		 * the IPv4 header checksum implicitly validated?
 		 */
 		csum = in_cksum_skip(m, m->m_pkthdr.len, hdr->csum_start);
 		*(uint16_t *)(mtodo(m, csum_off)) = csum;
 		m->m_pkthdr.csum_flags |= CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
 		m->m_pkthdr.csum_data = 0xFFFF;
 		break;
 	}
 #endif
 	default:
 		sc->vtnet_stats.rx_csum_bad_ethtype++;
 		return (1);
 	}
 
 	return (0);
 }
 
 static int
 vtnet_rxq_csum_data_valid(struct vtnet_rxq *rxq, struct mbuf *m,
     uint16_t etype, int hoff, struct virtio_net_hdr *hdr)
 {
 	struct vtnet_softc *sc;
 	int protocol;
 
 	sc = rxq->vtnrx_sc;
 
 	switch (etype) {
 #if defined(INET)
 	case ETHERTYPE_IP:
 		if (__predict_false(m->m_len < hoff + sizeof(struct ip)))
 			protocol = IPPROTO_DONE;
 		else {
 			struct ip *ip = (struct ip *)(m->m_data + hoff);
 			protocol = ip->ip_p;
 		}
 		break;
 #endif
 #if defined(INET6)
 	case ETHERTYPE_IPV6:
 		if (__predict_false(m->m_len < hoff + sizeof(struct ip6_hdr))
 		    || ip6_lasthdr(m, hoff, IPPROTO_IPV6, &protocol) < 0)
 			protocol = IPPROTO_DONE;
 		break;
 #endif
 	default:
 		protocol = IPPROTO_DONE;
 		break;
 	}
 
 	switch (protocol) {
 	case IPPROTO_TCP:
 	case IPPROTO_UDP:
 		m->m_pkthdr.csum_flags |= CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
 		m->m_pkthdr.csum_data = 0xFFFF;
 		break;
 	default:
 		/*
 		 * FreeBSD does not support checksum offloading of this
 		 * protocol. Let the stack re-verify the checksum later
 		 * if the protocol is supported.
 		 */
 #if 0
 		if_printf(sc->vtnet_ifp,
 		    "%s: checksum offload of unsupported protocol "
 		    "etype=%#x protocol=%d csum_start=%d csum_offset=%d\n",
 		    __func__, etype, protocol, hdr->csum_start,
 		    hdr->csum_offset);
 #endif
 		break;
 	}
 
 	return (0);
 }
 
 static int
 vtnet_rxq_csum(struct vtnet_rxq *rxq, struct mbuf *m,
     struct virtio_net_hdr *hdr)
 {
 	const struct ether_header *eh;
 	int hoff;
 	uint16_t etype;
 
 	eh = mtod(m, const struct ether_header *);
 	etype = ntohs(eh->ether_type);
 	if (etype == ETHERTYPE_VLAN) {
 		/* TODO BMV: Handle QinQ. */
 		const struct ether_vlan_header *evh =
 		    mtod(m, const struct ether_vlan_header *);
 		etype = ntohs(evh->evl_proto);
 		hoff = sizeof(struct ether_vlan_header);
 	} else
 		hoff = sizeof(struct ether_header);
 
 	if (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM)
 		return (vtnet_rxq_csum_needs_csum(rxq, m, etype, hoff, hdr));
 	else /* VIRTIO_NET_HDR_F_DATA_VALID */
 		return (vtnet_rxq_csum_data_valid(rxq, m, etype, hoff, hdr));
 }
 
 static void
 vtnet_rxq_discard_merged_bufs(struct vtnet_rxq *rxq, int nbufs)
 {
 	struct mbuf *m;
 
 	while (--nbufs > 0) {
 		m = virtqueue_dequeue(rxq->vtnrx_vq, NULL);
 		if (m == NULL)
 			break;
 		vtnet_rxq_discard_buf(rxq, m);
 	}
 }
 
 static void
 vtnet_rxq_discard_buf(struct vtnet_rxq *rxq, struct mbuf *m)
 {
 	int error;
 
 	/*
 	 * Requeue the discarded mbuf. This should always be successful
 	 * since it was just dequeued.
 	 */
 	error = vtnet_rxq_enqueue_buf(rxq, m);
 	KASSERT(error == 0,
 	    ("%s: cannot requeue discarded mbuf %d", __func__, error));
 }
 
 static int
 vtnet_rxq_merged_eof(struct vtnet_rxq *rxq, struct mbuf *m_head, int nbufs)
 {
 	struct vtnet_softc *sc;
 	struct virtqueue *vq;
 	struct mbuf *m_tail;
 
 	sc = rxq->vtnrx_sc;
 	vq = rxq->vtnrx_vq;
 	m_tail = m_head;
 
 	while (--nbufs > 0) {
 		struct mbuf *m;
 		int len;
 
 		m = virtqueue_dequeue(vq, &len);
 		if (m == NULL) {
 			rxq->vtnrx_stats.vrxs_ierrors++;
 			goto fail;
 		}
 
 		if (vtnet_rxq_new_buf(rxq) != 0) {
 			rxq->vtnrx_stats.vrxs_iqdrops++;
 			vtnet_rxq_discard_buf(rxq, m);
 			if (nbufs > 1)
 				vtnet_rxq_discard_merged_bufs(rxq, nbufs);
 			goto fail;
 		}
 
 		if (m->m_len < len)
 			len = m->m_len;
 
 		m->m_len = len;
 		m->m_flags &= ~M_PKTHDR;
 
 		m_head->m_pkthdr.len += len;
 		m_tail->m_next = m;
 		m_tail = m;
 	}
 
 	return (0);
 
 fail:
 	sc->vtnet_stats.rx_mergeable_failed++;
 	m_freem(m_head);
 
 	return (1);
 }
 
 #if defined(INET) || defined(INET6)
 static int
 vtnet_lro_rx(struct vtnet_rxq *rxq, struct mbuf *m)
 {
 	struct lro_ctrl *lro;
 
 	lro = &rxq->vtnrx_lro;
 
 	if (lro->lro_mbuf_max != 0) {
 		tcp_lro_queue_mbuf(lro, m);
 		return (0);
 	}
 
 	return (tcp_lro_rx(lro, m, 0));
 }
 #endif
 
 static void
 vtnet_rxq_input(struct vtnet_rxq *rxq, struct mbuf *m,
     struct virtio_net_hdr *hdr)
 {
 	struct vtnet_softc *sc;
 	struct ifnet *ifp;
 
 	sc = rxq->vtnrx_sc;
 	ifp = sc->vtnet_ifp;
 
 	if (ifp->if_capenable & IFCAP_VLAN_HWTAGGING) {
 		struct ether_header *eh = mtod(m, struct ether_header *);
 		if (eh->ether_type == htons(ETHERTYPE_VLAN)) {
 			vtnet_vlan_tag_remove(m);
 			/*
 			 * With the 802.1Q header removed, update the
 			 * checksum starting location accordingly.
 			 */
 			if (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM)
 				hdr->csum_start -= ETHER_VLAN_ENCAP_LEN;
 		}
 	}
 
 	m->m_pkthdr.flowid = rxq->vtnrx_id;
 	M_HASHTYPE_SET(m, M_HASHTYPE_OPAQUE);
 
 	if (hdr->flags &
 	    (VIRTIO_NET_HDR_F_NEEDS_CSUM | VIRTIO_NET_HDR_F_DATA_VALID)) {
 		if (vtnet_rxq_csum(rxq, m, hdr) == 0)
 			rxq->vtnrx_stats.vrxs_csum++;
 		else
 			rxq->vtnrx_stats.vrxs_csum_failed++;
 	}
 
 	rxq->vtnrx_stats.vrxs_ipackets++;
 	rxq->vtnrx_stats.vrxs_ibytes += m->m_pkthdr.len;
 
 #if defined(INET) || defined(INET6)
 	if (vtnet_software_lro(sc) && ifp->if_capenable & IFCAP_LRO) {
 		if (vtnet_lro_rx(rxq, m) == 0)
 			return;
 	}
 #endif
 
 	(*ifp->if_input)(ifp, m);
 }
 
 static int
 vtnet_rxq_eof(struct vtnet_rxq *rxq)
 {
 	struct virtio_net_hdr lhdr, *hdr;
 	struct vtnet_softc *sc;
 	struct ifnet *ifp;
 	struct virtqueue *vq;
 	int deq, count;
 
 	sc = rxq->vtnrx_sc;
 	vq = rxq->vtnrx_vq;
 	ifp = sc->vtnet_ifp;
 	deq = 0;
 	count = sc->vtnet_rx_process_limit;
 
 	VTNET_RXQ_LOCK_ASSERT(rxq);
 
 	while (count-- > 0) {
 		struct mbuf *m;
 		int len, nbufs, adjsz;
 
 		m = virtqueue_dequeue(vq, &len);
 		if (m == NULL)
 			break;
 		deq++;
 
 		if (len < sc->vtnet_hdr_size + ETHER_HDR_LEN) {
 			rxq->vtnrx_stats.vrxs_ierrors++;
 			vtnet_rxq_discard_buf(rxq, m);
 			continue;
 		}
 
 		if (sc->vtnet_flags & VTNET_FLAG_MRG_RXBUFS) {
 			struct virtio_net_hdr_mrg_rxbuf *mhdr =
 			    mtod(m, struct virtio_net_hdr_mrg_rxbuf *);
 			nbufs = vtnet_htog16(sc, mhdr->num_buffers);
 			adjsz = sizeof(struct virtio_net_hdr_mrg_rxbuf);
 		} else if (vtnet_modern(sc)) {
 			nbufs = 1; /* num_buffers is always 1 */
 			adjsz = sizeof(struct virtio_net_hdr_v1);
 		} else {
 			nbufs = 1;
 			adjsz = sizeof(struct vtnet_rx_header);
 			/*
 			 * Account for our gap between the header and start of
 			 * data to keep the segments separated.
 			 */
 			len += VTNET_RX_HEADER_PAD;
 		}
 
 		if (vtnet_rxq_replace_buf(rxq, m, len) != 0) {
 			rxq->vtnrx_stats.vrxs_iqdrops++;
 			vtnet_rxq_discard_buf(rxq, m);
 			if (nbufs > 1)
 				vtnet_rxq_discard_merged_bufs(rxq, nbufs);
 			continue;
 		}
 
 		m->m_pkthdr.len = len;
 		m->m_pkthdr.rcvif = ifp;
 		m->m_pkthdr.csum_flags = 0;
 
 		if (nbufs > 1) {
 			/* Dequeue the rest of chain. */
 			if (vtnet_rxq_merged_eof(rxq, m, nbufs) != 0)
 				continue;
 		}
 
 		/*
 		 * Save an endian swapped version of the header prior to it
 		 * being stripped. The header is always at the start of the
 		 * mbuf data. num_buffers was already saved (and not needed)
 		 * so use the standard header.
 		 */
 		hdr = mtod(m, struct virtio_net_hdr *);
 		lhdr.flags = hdr->flags;
 		lhdr.gso_type = hdr->gso_type;
 		lhdr.hdr_len = vtnet_htog16(sc, hdr->hdr_len);
 		lhdr.gso_size = vtnet_htog16(sc, hdr->gso_size);
 		lhdr.csum_start = vtnet_htog16(sc, hdr->csum_start);
 		lhdr.csum_offset = vtnet_htog16(sc, hdr->csum_offset);
 		m_adj(m, adjsz);
 
 		if (PFIL_HOOKED_IN(sc->vtnet_pfil)) {
 			pfil_return_t pfil;
 
 			pfil = pfil_run_hooks(sc->vtnet_pfil, &m, ifp, PFIL_IN,
 			    NULL);
 			switch (pfil) {
 			case PFIL_REALLOCED:
 				m = pfil_mem2mbuf(m->m_data);
 				break;
 			case PFIL_DROPPED:
 			case PFIL_CONSUMED:
 				continue;
 			default:
 				KASSERT(pfil == PFIL_PASS,
 				    ("Filter returned %d!", pfil));
 			}
 		}
 
 		vtnet_rxq_input(rxq, m, &lhdr);
 	}
 
 	if (deq > 0) {
 #if defined(INET) || defined(INET6)
 		tcp_lro_flush_all(&rxq->vtnrx_lro);
 #endif
 		virtqueue_notify(vq);
 	}
 
 	return (count > 0 ? 0 : EAGAIN);
 }
 
 static void
 vtnet_rx_vq_process(struct vtnet_rxq *rxq, int tries)
 {
 	struct vtnet_softc *sc;
 	struct ifnet *ifp;
 	int more;
 #ifdef DEV_NETMAP
 	int nmirq;
 #endif /* DEV_NETMAP */
 
 	sc = rxq->vtnrx_sc;
 	ifp = sc->vtnet_ifp;
 
 	if (__predict_false(rxq->vtnrx_id >= sc->vtnet_act_vq_pairs)) {
 		/*
 		 * Ignore this interrupt. Either this is a spurious interrupt
 		 * or multiqueue without per-VQ MSIX so every queue needs to
 		 * be polled (a brain dead configuration we could try harder
 		 * to avoid).
 		 */
 		vtnet_rxq_disable_intr(rxq);
 		return;
 	}
 
 	VTNET_RXQ_LOCK(rxq);
 
 #ifdef DEV_NETMAP
 	/*
 	 * We call netmap_rx_irq() under lock to prevent concurrent calls.
 	 * This is not necessary to serialize the access to the RX vq, but
 	 * rather to avoid races that may happen if this interface is
 	 * attached to a VALE switch, which would cause received packets
 	 * to stall in the RX queue (nm_kr_tryget() could find the kring
 	 * busy when called from netmap_bwrap_intr_notify()).
 	 */
 	nmirq = netmap_rx_irq(ifp, rxq->vtnrx_id, &more);
 	if (nmirq != NM_IRQ_PASS) {
 		VTNET_RXQ_UNLOCK(rxq);
 		if (nmirq == NM_IRQ_RESCHED) {
 			taskqueue_enqueue(rxq->vtnrx_tq, &rxq->vtnrx_intrtask);
 		}
 		return;
 	}
 #endif /* DEV_NETMAP */
 
 again:
 	if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) {
 		VTNET_RXQ_UNLOCK(rxq);
 		return;
 	}
 
 	more = vtnet_rxq_eof(rxq);
 	if (more || vtnet_rxq_enable_intr(rxq) != 0) {
 		if (!more)
 			vtnet_rxq_disable_intr(rxq);
 		/*
 		 * This is an occasional condition or race (when !more),
 		 * so retry a few times before scheduling the taskqueue.
 		 */
 		if (tries-- > 0)
 			goto again;
 
 		rxq->vtnrx_stats.vrxs_rescheduled++;
 		VTNET_RXQ_UNLOCK(rxq);
 		taskqueue_enqueue(rxq->vtnrx_tq, &rxq->vtnrx_intrtask);
 	} else
 		VTNET_RXQ_UNLOCK(rxq);
 }
 
 static void
 vtnet_rx_vq_intr(void *xrxq)
 {
 	struct vtnet_rxq *rxq;
 
 	rxq = xrxq;
 	vtnet_rx_vq_process(rxq, VTNET_INTR_DISABLE_RETRIES);
 }
 
 static void
 vtnet_rxq_tq_intr(void *xrxq, int pending)
 {
 	struct vtnet_rxq *rxq;
 
 	rxq = xrxq;
 	vtnet_rx_vq_process(rxq, 0);
 }
 
 static int
 vtnet_txq_intr_threshold(struct vtnet_txq *txq)
 {
 	struct vtnet_softc *sc;
 	int threshold;
 
 	sc = txq->vtntx_sc;
 
 	/*
 	 * The Tx interrupt is disabled until the queue free count falls
 	 * below our threshold. Completed frames are drained from the Tx
 	 * virtqueue before transmitting new frames and in the watchdog
 	 * callout, so the frequency of Tx interrupts is greatly reduced,
 	 * at the cost of not freeing mbufs as quickly as they otherwise
 	 * would be.
 	 */
 	threshold = virtqueue_size(txq->vtntx_vq) / 4;
 
 	/*
 	 * Without indirect descriptors, leave enough room for the most
 	 * segments we handle.
 	 */
 	if ((sc->vtnet_flags & VTNET_FLAG_INDIRECT) == 0 &&
 	    threshold < sc->vtnet_tx_nsegs)
 		threshold = sc->vtnet_tx_nsegs;
 
 	return (threshold);
 }
 
 static int
 vtnet_txq_below_threshold(struct vtnet_txq *txq)
 {
 	struct virtqueue *vq;
 
 	vq = txq->vtntx_vq;
 
 	return (virtqueue_nfree(vq) <= txq->vtntx_intr_threshold);
 }
 
 static int
 vtnet_txq_notify(struct vtnet_txq *txq)
 {
 	struct virtqueue *vq;
 
 	vq = txq->vtntx_vq;
 
 	txq->vtntx_watchdog = VTNET_TX_TIMEOUT;
 	virtqueue_notify(vq);
 
 	if (vtnet_txq_enable_intr(txq) == 0)
 		return (0);
 
 	/*
 	 * Drain frames that were completed since last checked. If this
 	 * causes the queue to go above the threshold, the caller should
 	 * continue transmitting.
 	 */
 	if (vtnet_txq_eof(txq) != 0 && vtnet_txq_below_threshold(txq) == 0) {
 		virtqueue_disable_intr(vq);
 		return (1);
 	}
 
 	return (0);
 }
 
 static void
 vtnet_txq_free_mbufs(struct vtnet_txq *txq)
 {
 	struct virtqueue *vq;
 	struct vtnet_tx_header *txhdr;
 	int last;
 #ifdef DEV_NETMAP
 	struct netmap_kring *kring = netmap_kring_on(NA(txq->vtntx_sc->vtnet_ifp),
 							txq->vtntx_id, NR_TX);
 #else  /* !DEV_NETMAP */
 	void *kring = NULL;
 #endif /* !DEV_NETMAP */
 
 	vq = txq->vtntx_vq;
 	last = 0;
 
 	while ((txhdr = virtqueue_drain(vq, &last)) != NULL) {
 		if (kring == NULL) {
 			m_freem(txhdr->vth_mbuf);
 			uma_zfree(vtnet_tx_header_zone, txhdr);
 		}
 	}
 
 	KASSERT(virtqueue_empty(vq),
 	    ("%s: mbufs remaining in tx queue %p", __func__, txq));
 }
 
 /*
  * BMV: This can go away once we finally have offsets in the mbuf header.
  */
 static int
 vtnet_txq_offload_ctx(struct vtnet_txq *txq, struct mbuf *m, int *etype,
     int *proto, int *start)
 {
 	struct vtnet_softc *sc;
 	struct ether_vlan_header *evh;
 	int offset;
 
 	sc = txq->vtntx_sc;
 
 	evh = mtod(m, struct ether_vlan_header *);
 	if (evh->evl_encap_proto == htons(ETHERTYPE_VLAN)) {
 		/* BMV: We should handle nested VLAN tags too. */
 		*etype = ntohs(evh->evl_proto);
 		offset = sizeof(struct ether_vlan_header);
 	} else {
 		*etype = ntohs(evh->evl_encap_proto);
 		offset = sizeof(struct ether_header);
 	}
 
 	switch (*etype) {
 #if defined(INET)
 	case ETHERTYPE_IP: {
 		struct ip *ip, iphdr;
 		if (__predict_false(m->m_len < offset + sizeof(struct ip))) {
 			m_copydata(m, offset, sizeof(struct ip),
 			    (caddr_t) &iphdr);
 			ip = &iphdr;
 		} else
 			ip = (struct ip *)(m->m_data + offset);
 		*proto = ip->ip_p;
 		*start = offset + (ip->ip_hl << 2);
 		break;
 	}
 #endif
 #if defined(INET6)
 	case ETHERTYPE_IPV6:
 		*proto = -1;
 		*start = ip6_lasthdr(m, offset, IPPROTO_IPV6, proto);
 		/* Assert the network stack sent us a valid packet. */
 		KASSERT(*start > offset,
 		    ("%s: mbuf %p start %d offset %d proto %d", __func__, m,
 		    *start, offset, *proto));
 		break;
 #endif
 	default:
 		sc->vtnet_stats.tx_csum_bad_ethtype++;
 		return (EINVAL);
 	}
 
 	return (0);
 }
 
 static int
 vtnet_txq_offload_tso(struct vtnet_txq *txq, struct mbuf *m, int eth_type,
     int offset, struct virtio_net_hdr *hdr)
 {
 	static struct timeval lastecn;
 	static int curecn;
 	struct vtnet_softc *sc;
 	struct tcphdr *tcp, tcphdr;
 
 	sc = txq->vtntx_sc;
 
 	if (__predict_false(m->m_len < offset + sizeof(struct tcphdr))) {
 		m_copydata(m, offset, sizeof(struct tcphdr), (caddr_t) &tcphdr);
 		tcp = &tcphdr;
 	} else
 		tcp = (struct tcphdr *)(m->m_data + offset);
 
 	hdr->hdr_len = vtnet_gtoh16(sc, offset + (tcp->th_off << 2));
 	hdr->gso_size = vtnet_gtoh16(sc, m->m_pkthdr.tso_segsz);
 	hdr->gso_type = eth_type == ETHERTYPE_IP ? VIRTIO_NET_HDR_GSO_TCPV4 :
 	    VIRTIO_NET_HDR_GSO_TCPV6;
 
 	if (tcp->th_flags & TH_CWR) {
 		/*
 		 * Drop if VIRTIO_NET_F_HOST_ECN was not negotiated. In FreeBSD,
 		 * ECN support is not on a per-interface basis, but globally via
 		 * the net.inet.tcp.ecn.enable sysctl knob. The default is off.
 		 */
 		if ((sc->vtnet_flags & VTNET_FLAG_TSO_ECN) == 0) {
 			if (ppsratecheck(&lastecn, &curecn, 1))
 				if_printf(sc->vtnet_ifp,
 				    "TSO with ECN not negotiated with host\n");
 			return (ENOTSUP);
 		}
 		hdr->gso_type |= VIRTIO_NET_HDR_GSO_ECN;
 	}
 
 	txq->vtntx_stats.vtxs_tso++;
 
 	return (0);
 }
 
 static struct mbuf *
 vtnet_txq_offload(struct vtnet_txq *txq, struct mbuf *m,
     struct virtio_net_hdr *hdr)
 {
 	struct vtnet_softc *sc;
 	int flags, etype, csum_start, proto, error;
 
 	sc = txq->vtntx_sc;
 	flags = m->m_pkthdr.csum_flags;
 
 	error = vtnet_txq_offload_ctx(txq, m, &etype, &proto, &csum_start);
 	if (error)
 		goto drop;
 
 	if ((etype == ETHERTYPE_IP && flags & VTNET_CSUM_OFFLOAD) ||
 	    (etype == ETHERTYPE_IPV6 && flags & VTNET_CSUM_OFFLOAD_IPV6)) {
 		/*
 		 * We could compare the IP protocol vs the CSUM_ flag too,
 		 * but that really should not be necessary.
 		 */
 		hdr->flags |= VIRTIO_NET_HDR_F_NEEDS_CSUM;
 		hdr->csum_start = vtnet_gtoh16(sc, csum_start);
 		hdr->csum_offset = vtnet_gtoh16(sc, m->m_pkthdr.csum_data);
 		txq->vtntx_stats.vtxs_csum++;
 	}
 
 	if (flags & CSUM_TSO) {
 		if (__predict_false(proto != IPPROTO_TCP)) {
 			/* Likely failed to correctly parse the mbuf. */
 			sc->vtnet_stats.tx_tso_not_tcp++;
 			goto drop;
 		}
 
 		KASSERT(hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM,
 		    ("%s: mbuf %p TSO without checksum offload %#x",
 		    __func__, m, flags));
 
 		error = vtnet_txq_offload_tso(txq, m, etype, csum_start, hdr);
 		if (error)
 			goto drop;
 	}
 
 	return (m);
 
 drop:
 	m_freem(m);
 	return (NULL);
 }
 
 static int
 vtnet_txq_enqueue_buf(struct vtnet_txq *txq, struct mbuf **m_head,
     struct vtnet_tx_header *txhdr)
 {
 	struct vtnet_softc *sc;
 	struct virtqueue *vq;
 	struct sglist *sg;
 	struct mbuf *m;
 	int error;
 
 	sc = txq->vtntx_sc;
 	vq = txq->vtntx_vq;
 	sg = txq->vtntx_sg;
 	m = *m_head;
 
 	sglist_reset(sg);
 	error = sglist_append(sg, &txhdr->vth_uhdr, sc->vtnet_hdr_size);
 	if (error != 0 || sg->sg_nseg != 1) {
 		KASSERT(0, ("%s: cannot add header to sglist error %d nseg %d",
 		    __func__, error, sg->sg_nseg));
 		goto fail;
 	}
 
 	error = sglist_append_mbuf(sg, m);
 	if (error) {
 		m = m_defrag(m, M_NOWAIT);
 		if (m == NULL)
 			goto fail;
 
 		*m_head = m;
 		sc->vtnet_stats.tx_defragged++;
 
 		error = sglist_append_mbuf(sg, m);
 		if (error)
 			goto fail;
 	}
 
 	txhdr->vth_mbuf = m;
 	error = virtqueue_enqueue(vq, txhdr, sg, sg->sg_nseg, 0);
 
 	return (error);
 
 fail:
 	sc->vtnet_stats.tx_defrag_failed++;
 	m_freem(*m_head);
 	*m_head = NULL;
 
 	return (ENOBUFS);
 }
 
 static int
 vtnet_txq_encap(struct vtnet_txq *txq, struct mbuf **m_head, int flags)
 {
 	struct vtnet_tx_header *txhdr;
 	struct virtio_net_hdr *hdr;
 	struct mbuf *m;
 	int error;
 
 	m = *m_head;
 	M_ASSERTPKTHDR(m);
 
 	txhdr = uma_zalloc(vtnet_tx_header_zone, flags | M_ZERO);
 	if (txhdr == NULL) {
 		m_freem(m);
 		*m_head = NULL;
 		return (ENOMEM);
 	}
 
 	/*
 	 * Always use the non-mergeable header, regardless if mergable headers
 	 * were negotiated, because for transmit num_buffers is always zero.
 	 * The vtnet_hdr_size is used to enqueue the right header size segment.
 	 */
 	hdr = &txhdr->vth_uhdr.hdr;
 
 	if (m->m_flags & M_VLANTAG) {
 		m = ether_vlanencap(m, m->m_pkthdr.ether_vtag);
 		if ((*m_head = m) == NULL) {
 			error = ENOBUFS;
 			goto fail;
 		}
 		m->m_flags &= ~M_VLANTAG;
 	}
 
 	if (m->m_pkthdr.csum_flags & VTNET_CSUM_ALL_OFFLOAD) {
 		m = vtnet_txq_offload(txq, m, hdr);
 		if ((*m_head = m) == NULL) {
 			error = ENOBUFS;
 			goto fail;
 		}
 	}
 
 	error = vtnet_txq_enqueue_buf(txq, m_head, txhdr);
 fail:
 	if (error)
 		uma_zfree(vtnet_tx_header_zone, txhdr);
 
 	return (error);
 }
 
 #ifdef VTNET_LEGACY_TX
 
 static void
 vtnet_start_locked(struct vtnet_txq *txq, struct ifnet *ifp)
 {
 	struct vtnet_softc *sc;
 	struct virtqueue *vq;
 	struct mbuf *m0;
 	int tries, enq;
 
 	sc = txq->vtntx_sc;
 	vq = txq->vtntx_vq;
 	tries = 0;
 
 	VTNET_TXQ_LOCK_ASSERT(txq);
 
 	if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
 	    sc->vtnet_link_active == 0)
 		return;
 
 	vtnet_txq_eof(txq);
 
 again:
 	enq = 0;
 
 	while (!IFQ_DRV_IS_EMPTY(&ifp->if_snd)) {
 		if (virtqueue_full(vq))
 			break;
 
 		IFQ_DRV_DEQUEUE(&ifp->if_snd, m0);
 		if (m0 == NULL)
 			break;
 
 		if (vtnet_txq_encap(txq, &m0, M_NOWAIT) != 0) {
 			if (m0 != NULL)
 				IFQ_DRV_PREPEND(&ifp->if_snd, m0);
 			break;
 		}
 
 		enq++;
 		ETHER_BPF_MTAP(ifp, m0);
 	}
 
 	if (enq > 0 && vtnet_txq_notify(txq) != 0) {
 		if (tries++ < VTNET_NOTIFY_RETRIES)
 			goto again;
 
 		txq->vtntx_stats.vtxs_rescheduled++;
 		taskqueue_enqueue(txq->vtntx_tq, &txq->vtntx_intrtask);
 	}
 }
 
 static void
 vtnet_start(struct ifnet *ifp)
 {
 	struct vtnet_softc *sc;
 	struct vtnet_txq *txq;
 
 	sc = ifp->if_softc;
 	txq = &sc->vtnet_txqs[0];
 
 	VTNET_TXQ_LOCK(txq);
 	vtnet_start_locked(txq, ifp);
 	VTNET_TXQ_UNLOCK(txq);
 }
 
 #else /* !VTNET_LEGACY_TX */
 
 static int
 vtnet_txq_mq_start_locked(struct vtnet_txq *txq, struct mbuf *m)
 {
 	struct vtnet_softc *sc;
 	struct virtqueue *vq;
 	struct buf_ring *br;
 	struct ifnet *ifp;
 	int enq, tries, error;
 
 	sc = txq->vtntx_sc;
 	vq = txq->vtntx_vq;
 	br = txq->vtntx_br;
 	ifp = sc->vtnet_ifp;
 	tries = 0;
 	error = 0;
 
 	VTNET_TXQ_LOCK_ASSERT(txq);
 
 	if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
 	    sc->vtnet_link_active == 0) {
 		if (m != NULL)
 			error = drbr_enqueue(ifp, br, m);
 		return (error);
 	}
 
 	if (m != NULL) {
 		error = drbr_enqueue(ifp, br, m);
 		if (error)
 			return (error);
 	}
 
 	vtnet_txq_eof(txq);
 
 again:
 	enq = 0;
 
 	while ((m = drbr_peek(ifp, br)) != NULL) {
 		if (virtqueue_full(vq)) {
 			drbr_putback(ifp, br, m);
 			break;
 		}
 
 		if (vtnet_txq_encap(txq, &m, M_NOWAIT) != 0) {
 			if (m != NULL)
 				drbr_putback(ifp, br, m);
 			else
 				drbr_advance(ifp, br);
 			break;
 		}
 		drbr_advance(ifp, br);
 
 		enq++;
 		ETHER_BPF_MTAP(ifp, m);
 	}
 
 	if (enq > 0 && vtnet_txq_notify(txq) != 0) {
 		if (tries++ < VTNET_NOTIFY_RETRIES)
 			goto again;
 
 		txq->vtntx_stats.vtxs_rescheduled++;
 		taskqueue_enqueue(txq->vtntx_tq, &txq->vtntx_intrtask);
 	}
 
 	return (0);
 }
 
 static int
 vtnet_txq_mq_start(struct ifnet *ifp, struct mbuf *m)
 {
 	struct vtnet_softc *sc;
 	struct vtnet_txq *txq;
 	int i, npairs, error;
 
 	sc = ifp->if_softc;
 	npairs = sc->vtnet_act_vq_pairs;
 
 	if (M_HASHTYPE_GET(m) != M_HASHTYPE_NONE)
 		i = m->m_pkthdr.flowid % npairs;
 	else
 		i = curcpu % npairs;
 
 	txq = &sc->vtnet_txqs[i];
 
 	if (VTNET_TXQ_TRYLOCK(txq) != 0) {
 		error = vtnet_txq_mq_start_locked(txq, m);
 		VTNET_TXQ_UNLOCK(txq);
 	} else {
 		error = drbr_enqueue(ifp, txq->vtntx_br, m);
 		taskqueue_enqueue(txq->vtntx_tq, &txq->vtntx_defrtask);
 	}
 
 	return (error);
 }
 
 static void
 vtnet_txq_tq_deferred(void *xtxq, int pending)
 {
 	struct vtnet_softc *sc;
 	struct vtnet_txq *txq;
 
 	txq = xtxq;
 	sc = txq->vtntx_sc;
 
 	VTNET_TXQ_LOCK(txq);
 	if (!drbr_empty(sc->vtnet_ifp, txq->vtntx_br))
 		vtnet_txq_mq_start_locked(txq, NULL);
 	VTNET_TXQ_UNLOCK(txq);
 }
 
 #endif /* VTNET_LEGACY_TX */
 
 static void
 vtnet_txq_start(struct vtnet_txq *txq)
 {
 	struct vtnet_softc *sc;
 	struct ifnet *ifp;
 
 	sc = txq->vtntx_sc;
 	ifp = sc->vtnet_ifp;
 
 #ifdef VTNET_LEGACY_TX
 	if (!IFQ_DRV_IS_EMPTY(&ifp->if_snd))
 		vtnet_start_locked(txq, ifp);
 #else
 	if (!drbr_empty(ifp, txq->vtntx_br))
 		vtnet_txq_mq_start_locked(txq, NULL);
 #endif
 }
 
 static void
 vtnet_txq_tq_intr(void *xtxq, int pending)
 {
 	struct vtnet_softc *sc;
 	struct vtnet_txq *txq;
 	struct ifnet *ifp;
 
 	txq = xtxq;
 	sc = txq->vtntx_sc;
 	ifp = sc->vtnet_ifp;
 
 	VTNET_TXQ_LOCK(txq);
 
 	if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) {
 		VTNET_TXQ_UNLOCK(txq);
 		return;
 	}
 
 	vtnet_txq_eof(txq);
 	vtnet_txq_start(txq);
 
 	VTNET_TXQ_UNLOCK(txq);
 }
 
 static int
 vtnet_txq_eof(struct vtnet_txq *txq)
 {
 	struct virtqueue *vq;
 	struct vtnet_tx_header *txhdr;
 	struct mbuf *m;
 	int deq;
 
 	vq = txq->vtntx_vq;
 	deq = 0;
 	VTNET_TXQ_LOCK_ASSERT(txq);
 
 	while ((txhdr = virtqueue_dequeue(vq, NULL)) != NULL) {
 		m = txhdr->vth_mbuf;
 		deq++;
 
 		txq->vtntx_stats.vtxs_opackets++;
 		txq->vtntx_stats.vtxs_obytes += m->m_pkthdr.len;
 		if (m->m_flags & M_MCAST)
 			txq->vtntx_stats.vtxs_omcasts++;
 
 		m_freem(m);
 		uma_zfree(vtnet_tx_header_zone, txhdr);
 	}
 
 	if (virtqueue_empty(vq))
 		txq->vtntx_watchdog = 0;
 
 	return (deq);
 }
 
 static void
 vtnet_tx_vq_intr(void *xtxq)
 {
 	struct vtnet_softc *sc;
 	struct vtnet_txq *txq;
 	struct ifnet *ifp;
 
 	txq = xtxq;
 	sc = txq->vtntx_sc;
 	ifp = sc->vtnet_ifp;
 
 	if (__predict_false(txq->vtntx_id >= sc->vtnet_act_vq_pairs)) {
 		/*
 		 * Ignore this interrupt. Either this is a spurious interrupt
 		 * or multiqueue without per-VQ MSIX so every queue needs to
 		 * be polled (a brain dead configuration we could try harder
 		 * to avoid).
 		 */
 		vtnet_txq_disable_intr(txq);
 		return;
 	}
 
 #ifdef DEV_NETMAP
 	if (netmap_tx_irq(ifp, txq->vtntx_id) != NM_IRQ_PASS)
 		return;
 #endif /* DEV_NETMAP */
 
 	VTNET_TXQ_LOCK(txq);
 
 	if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) {
 		VTNET_TXQ_UNLOCK(txq);
 		return;
 	}
 
 	vtnet_txq_eof(txq);
 	vtnet_txq_start(txq);
 
 	VTNET_TXQ_UNLOCK(txq);
 }
 
 static void
 vtnet_tx_start_all(struct vtnet_softc *sc)
 {
 	struct vtnet_txq *txq;
 	int i;
 
 	VTNET_CORE_LOCK_ASSERT(sc);
 
 	for (i = 0; i < sc->vtnet_act_vq_pairs; i++) {
 		txq = &sc->vtnet_txqs[i];
 
 		VTNET_TXQ_LOCK(txq);
 		vtnet_txq_start(txq);
 		VTNET_TXQ_UNLOCK(txq);
 	}
 }
 
 #ifndef VTNET_LEGACY_TX
 static void
 vtnet_qflush(struct ifnet *ifp)
 {
 	struct vtnet_softc *sc;
 	struct vtnet_txq *txq;
 	struct mbuf *m;
 	int i;
 
 	sc = ifp->if_softc;
 
 	for (i = 0; i < sc->vtnet_act_vq_pairs; i++) {
 		txq = &sc->vtnet_txqs[i];
 
 		VTNET_TXQ_LOCK(txq);
 		while ((m = buf_ring_dequeue_sc(txq->vtntx_br)) != NULL)
 			m_freem(m);
 		VTNET_TXQ_UNLOCK(txq);
 	}
 
 	if_qflush(ifp);
 }
 #endif
 
 static int
 vtnet_watchdog(struct vtnet_txq *txq)
 {
 	struct ifnet *ifp;
 
 	ifp = txq->vtntx_sc->vtnet_ifp;
 
 	VTNET_TXQ_LOCK(txq);
 	if (txq->vtntx_watchdog == 1) {
 		/*
 		 * Only drain completed frames if the watchdog is about to
 		 * expire. If any frames were drained, there may be enough
 		 * free descriptors now available to transmit queued frames.
 		 * In that case, the timer will immediately be decremented
 		 * below, but the timeout is generous enough that should not
 		 * be a problem.
 		 */
 		if (vtnet_txq_eof(txq) != 0)
 			vtnet_txq_start(txq);
 	}
 
 	if (txq->vtntx_watchdog == 0 || --txq->vtntx_watchdog) {
 		VTNET_TXQ_UNLOCK(txq);
 		return (0);
 	}
 	VTNET_TXQ_UNLOCK(txq);
 
 	if_printf(ifp, "watchdog timeout on queue %d\n", txq->vtntx_id);
 	return (1);
 }
 
 static void
 vtnet_accum_stats(struct vtnet_softc *sc, struct vtnet_rxq_stats *rxacc,
     struct vtnet_txq_stats *txacc)
 {
 
 	bzero(rxacc, sizeof(struct vtnet_rxq_stats));
 	bzero(txacc, sizeof(struct vtnet_txq_stats));
 
 	for (int i = 0; i < sc->vtnet_max_vq_pairs; i++) {
 		struct vtnet_rxq_stats *rxst;
 		struct vtnet_txq_stats *txst;
 
 		rxst = &sc->vtnet_rxqs[i].vtnrx_stats;
 		rxacc->vrxs_ipackets += rxst->vrxs_ipackets;
 		rxacc->vrxs_ibytes += rxst->vrxs_ibytes;
 		rxacc->vrxs_iqdrops += rxst->vrxs_iqdrops;
 		rxacc->vrxs_csum += rxst->vrxs_csum;
 		rxacc->vrxs_csum_failed += rxst->vrxs_csum_failed;
 		rxacc->vrxs_rescheduled += rxst->vrxs_rescheduled;
 
 		txst = &sc->vtnet_txqs[i].vtntx_stats;
 		txacc->vtxs_opackets += txst->vtxs_opackets;
 		txacc->vtxs_obytes += txst->vtxs_obytes;
 		txacc->vtxs_csum += txst->vtxs_csum;
 		txacc->vtxs_tso += txst->vtxs_tso;
 		txacc->vtxs_rescheduled += txst->vtxs_rescheduled;
 	}
 }
 
 static uint64_t
 vtnet_get_counter(if_t ifp, ift_counter cnt)
 {
 	struct vtnet_softc *sc;
 	struct vtnet_rxq_stats rxaccum;
 	struct vtnet_txq_stats txaccum;
 
 	sc = if_getsoftc(ifp);
 	vtnet_accum_stats(sc, &rxaccum, &txaccum);
 
 	switch (cnt) {
 	case IFCOUNTER_IPACKETS:
 		return (rxaccum.vrxs_ipackets);
 	case IFCOUNTER_IQDROPS:
 		return (rxaccum.vrxs_iqdrops);
 	case IFCOUNTER_IERRORS:
 		return (rxaccum.vrxs_ierrors);
 	case IFCOUNTER_OPACKETS:
 		return (txaccum.vtxs_opackets);
 #ifndef VTNET_LEGACY_TX
 	case IFCOUNTER_OBYTES:
 		return (txaccum.vtxs_obytes);
 	case IFCOUNTER_OMCASTS:
 		return (txaccum.vtxs_omcasts);
 #endif
 	default:
 		return (if_get_counter_default(ifp, cnt));
 	}
 }
 
 static void
 vtnet_tick(void *xsc)
 {
 	struct vtnet_softc *sc;
 	struct ifnet *ifp;
 	int i, timedout;
 
 	sc = xsc;
 	ifp = sc->vtnet_ifp;
 	timedout = 0;
 
 	VTNET_CORE_LOCK_ASSERT(sc);
 
 	for (i = 0; i < sc->vtnet_act_vq_pairs; i++)
 		timedout |= vtnet_watchdog(&sc->vtnet_txqs[i]);
 
 	if (timedout != 0) {
 		ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
 		vtnet_init_locked(sc, 0);
 	} else
 		callout_schedule(&sc->vtnet_tick_ch, hz);
 }
 
 static void
 vtnet_start_taskqueues(struct vtnet_softc *sc)
 {
 	device_t dev;
 	struct vtnet_rxq *rxq;
 	struct vtnet_txq *txq;
 	int i, error;
 
 	dev = sc->vtnet_dev;
 
 	/*
 	 * Errors here are very difficult to recover from - we cannot
 	 * easily fail because, if this is during boot, we will hang
 	 * when freeing any successfully started taskqueues because
 	 * the scheduler isn't up yet.
 	 *
 	 * Most drivers just ignore the return value - it only fails
 	 * with ENOMEM so an error is not likely.
 	 */
 	for (i = 0; i < sc->vtnet_req_vq_pairs; i++) {
 		rxq = &sc->vtnet_rxqs[i];
 		error = taskqueue_start_threads(&rxq->vtnrx_tq, 1, PI_NET,
 		    "%s rxq %d", device_get_nameunit(dev), rxq->vtnrx_id);
 		if (error) {
 			device_printf(dev, "failed to start rx taskq %d\n",
 			    rxq->vtnrx_id);
 		}
 
 		txq = &sc->vtnet_txqs[i];
 		error = taskqueue_start_threads(&txq->vtntx_tq, 1, PI_NET,
 		    "%s txq %d", device_get_nameunit(dev), txq->vtntx_id);
 		if (error) {
 			device_printf(dev, "failed to start tx taskq %d\n",
 			    txq->vtntx_id);
 		}
 	}
 }
 
 static void
 vtnet_free_taskqueues(struct vtnet_softc *sc)
 {
 	struct vtnet_rxq *rxq;
 	struct vtnet_txq *txq;
 	int i;
 
 	for (i = 0; i < sc->vtnet_max_vq_pairs; i++) {
 		rxq = &sc->vtnet_rxqs[i];
 		if (rxq->vtnrx_tq != NULL) {
 			taskqueue_free(rxq->vtnrx_tq);
 			rxq->vtnrx_tq = NULL;
 		}
 
 		txq = &sc->vtnet_txqs[i];
 		if (txq->vtntx_tq != NULL) {
 			taskqueue_free(txq->vtntx_tq);
 			txq->vtntx_tq = NULL;
 		}
 	}
 }
 
 static void
 vtnet_drain_taskqueues(struct vtnet_softc *sc)
 {
 	struct vtnet_rxq *rxq;
 	struct vtnet_txq *txq;
 	int i;
 
 	for (i = 0; i < sc->vtnet_max_vq_pairs; i++) {
 		rxq = &sc->vtnet_rxqs[i];
 		if (rxq->vtnrx_tq != NULL)
 			taskqueue_drain(rxq->vtnrx_tq, &rxq->vtnrx_intrtask);
 
 		txq = &sc->vtnet_txqs[i];
 		if (txq->vtntx_tq != NULL) {
 			taskqueue_drain(txq->vtntx_tq, &txq->vtntx_intrtask);
 #ifndef VTNET_LEGACY_TX
 			taskqueue_drain(txq->vtntx_tq, &txq->vtntx_defrtask);
 #endif
 		}
 	}
 }
 
 static void
 vtnet_drain_rxtx_queues(struct vtnet_softc *sc)
 {
 	struct vtnet_rxq *rxq;
 	struct vtnet_txq *txq;
 	int i;
 
 	for (i = 0; i < sc->vtnet_max_vq_pairs; i++) {
 		rxq = &sc->vtnet_rxqs[i];
 		vtnet_rxq_free_mbufs(rxq);
 
 		txq = &sc->vtnet_txqs[i];
 		vtnet_txq_free_mbufs(txq);
 	}
 }
 
 static void
 vtnet_stop_rendezvous(struct vtnet_softc *sc)
 {
 	struct vtnet_rxq *rxq;
 	struct vtnet_txq *txq;
 	int i;
 
+	VTNET_CORE_LOCK_ASSERT(sc);
+
 	/*
 	 * Lock and unlock the per-queue mutex so we known the stop
 	 * state is visible. Doing only the active queues should be
 	 * sufficient, but it does not cost much extra to do all the
-	 * queues. Note we hold the core mutex here too.
+	 * queues.
 	 */
 	for (i = 0; i < sc->vtnet_max_vq_pairs; i++) {
 		rxq = &sc->vtnet_rxqs[i];
 		VTNET_RXQ_LOCK(rxq);
 		VTNET_RXQ_UNLOCK(rxq);
 
 		txq = &sc->vtnet_txqs[i];
 		VTNET_TXQ_LOCK(txq);
 		VTNET_TXQ_UNLOCK(txq);
 	}
 }
 
 static void
 vtnet_stop(struct vtnet_softc *sc)
 {
 	device_t dev;
 	struct ifnet *ifp;
 
 	dev = sc->vtnet_dev;
 	ifp = sc->vtnet_ifp;
 
 	VTNET_CORE_LOCK_ASSERT(sc);
 
 	ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
 	sc->vtnet_link_active = 0;
 	callout_stop(&sc->vtnet_tick_ch);
 
 	/* Only advisory. */
 	vtnet_disable_interrupts(sc);
 
 #ifdef DEV_NETMAP
 	/* Stop any pending txsync/rxsync and disable them. */
 	netmap_disable_all_rings(ifp);
 #endif /* DEV_NETMAP */
 
 	/*
 	 * Stop the host adapter. This resets it to the pre-initialized
 	 * state. It will not generate any interrupts until after it is
 	 * reinitialized.
 	 */
 	virtio_stop(dev);
 	vtnet_stop_rendezvous(sc);
 
-	/* Free any mbufs left in the virtqueues. */
 	vtnet_drain_rxtx_queues(sc);
+	sc->vtnet_act_vq_pairs = 1;
 }
 
 static int
 vtnet_virtio_reinit(struct vtnet_softc *sc)
 {
 	device_t dev;
 	struct ifnet *ifp;
 	uint64_t features;
 	int error;
 
 	dev = sc->vtnet_dev;
 	ifp = sc->vtnet_ifp;
 	features = sc->vtnet_negotiated_features;
 
 	/*
 	 * Re-negotiate with the host, removing any disabled receive
 	 * features. Transmit features are disabled only on our side
 	 * via if_capenable and if_hwassist.
 	 */
 
 	if ((ifp->if_capenable & (IFCAP_RXCSUM | IFCAP_RXCSUM_IPV6)) == 0)
 		features &= ~(VIRTIO_NET_F_GUEST_CSUM | VTNET_LRO_FEATURES);
 
 	if ((ifp->if_capenable & IFCAP_LRO) == 0)
 		features &= ~VTNET_LRO_FEATURES;
 
 	if ((ifp->if_capenable & IFCAP_VLAN_HWFILTER) == 0)
 		features &= ~VIRTIO_NET_F_CTRL_VLAN;
 
 	error = virtio_reinit(dev, features);
 	if (error) {
 		device_printf(dev, "virtio reinit error %d\n", error);
 		return (error);
 	}
 
 	sc->vtnet_features = features;
 	virtio_reinit_complete(dev);
 
 	return (0);
 }
 
 static void
 vtnet_init_rx_filters(struct vtnet_softc *sc)
 {
 	struct ifnet *ifp;
 
 	ifp = sc->vtnet_ifp;
 
 	if (sc->vtnet_flags & VTNET_FLAG_CTRL_RX) {
 		vtnet_rx_filter(sc);
 		vtnet_rx_filter_mac(sc);
 	}
 
 	if (ifp->if_capenable & IFCAP_VLAN_HWFILTER)
 		vtnet_rx_filter_vlan(sc);
 }
 
 static int
 vtnet_init_rx_queues(struct vtnet_softc *sc)
 {
 	device_t dev;
 	struct ifnet *ifp;
 	struct vtnet_rxq *rxq;
 	int i, clustersz, error;
 
 	dev = sc->vtnet_dev;
 	ifp = sc->vtnet_ifp;
 
 	clustersz = vtnet_rx_cluster_size(sc, ifp->if_mtu);
 	sc->vtnet_rx_clustersz = clustersz;
 
 	if (sc->vtnet_flags & VTNET_FLAG_LRO_NOMRG) {
 		sc->vtnet_rx_nmbufs = howmany(sizeof(struct vtnet_rx_header) +
 		    VTNET_MAX_RX_SIZE, clustersz);
 		KASSERT(sc->vtnet_rx_nmbufs < sc->vtnet_rx_nsegs,
 		    ("%s: too many rx mbufs %d for %d segments", __func__,
 		    sc->vtnet_rx_nmbufs, sc->vtnet_rx_nsegs));
 	} else
 		sc->vtnet_rx_nmbufs = 1;
 
 	for (i = 0; i < sc->vtnet_act_vq_pairs; i++) {
 		rxq = &sc->vtnet_rxqs[i];
 
 		/* Hold the lock to satisfy asserts. */
 		VTNET_RXQ_LOCK(rxq);
 		error = vtnet_rxq_populate(rxq);
 		VTNET_RXQ_UNLOCK(rxq);
 
 		if (error) {
 			device_printf(dev, "cannot populate Rx queue %d\n", i);
 			return (error);
 		}
 	}
 
 	return (0);
 }
 
 static int
 vtnet_init_tx_queues(struct vtnet_softc *sc)
 {
 	struct vtnet_txq *txq;
 	int i;
 
 	for (i = 0; i < sc->vtnet_act_vq_pairs; i++) {
 		txq = &sc->vtnet_txqs[i];
 		txq->vtntx_watchdog = 0;
 		txq->vtntx_intr_threshold = vtnet_txq_intr_threshold(txq);
 #ifdef DEV_NETMAP
 		netmap_reset(NA(sc->vtnet_ifp), NR_TX, i, 0);
 #endif /* DEV_NETMAP */
 	}
 
 	return (0);
 }
 
 static int
 vtnet_init_rxtx_queues(struct vtnet_softc *sc)
 {
 	int error;
 
 	error = vtnet_init_rx_queues(sc);
 	if (error)
 		return (error);
 
 	error = vtnet_init_tx_queues(sc);
 	if (error)
 		return (error);
 
 	return (0);
 }
 
 static void
 vtnet_set_active_vq_pairs(struct vtnet_softc *sc)
 {
 	device_t dev;
 	int npairs;
 
 	dev = sc->vtnet_dev;
 
 	if ((sc->vtnet_flags & VTNET_FLAG_MQ) == 0) {
 		sc->vtnet_act_vq_pairs = 1;
 		return;
 	}
 
 	npairs = sc->vtnet_req_vq_pairs;
 
 	if (vtnet_ctrl_mq_cmd(sc, npairs) != 0) {
 		device_printf(dev, "cannot set active queue pairs to %d, "
 		    "falling back to 1 queue pair\n", npairs);
 		npairs = 1;
 	}
 
 	sc->vtnet_act_vq_pairs = npairs;
 }
 
 static void
 vtnet_update_rx_offloads(struct vtnet_softc *sc)
 {
 	struct ifnet *ifp;
 	uint64_t features;
 	int error;
 
 	ifp = sc->vtnet_ifp;
 	features = sc->vtnet_features;
 
 	VTNET_CORE_LOCK_ASSERT(sc);
 
 	if (ifp->if_capabilities & (IFCAP_RXCSUM | IFCAP_RXCSUM_IPV6)) {
 		if (ifp->if_capenable & (IFCAP_RXCSUM | IFCAP_RXCSUM_IPV6))
 			features |= VIRTIO_NET_F_GUEST_CSUM;
 		else
 			features &= ~VIRTIO_NET_F_GUEST_CSUM;
 	}
 
 	if (ifp->if_capabilities & IFCAP_LRO && !vtnet_software_lro(sc)) {
 		if (ifp->if_capenable & IFCAP_LRO)
 			features |= VTNET_LRO_FEATURES;
 		else
 			features &= ~VTNET_LRO_FEATURES;
 	}
 
 	error = vtnet_ctrl_guest_offloads(sc,
 	    features & (VIRTIO_NET_F_GUEST_CSUM | VIRTIO_NET_F_GUEST_TSO4 |
 		        VIRTIO_NET_F_GUEST_TSO6 | VIRTIO_NET_F_GUEST_ECN  |
 			VIRTIO_NET_F_GUEST_UFO));
 	if (error) {
 		device_printf(sc->vtnet_dev,
 		    "%s: cannot update Rx features\n", __func__);
 		if (ifp->if_drv_flags & IFF_DRV_RUNNING) {
 			ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
 			vtnet_init_locked(sc, 0);
 		}
 	} else
 		sc->vtnet_features = features;
 }
 
 static int
 vtnet_reinit(struct vtnet_softc *sc)
 {
 	device_t dev;
 	struct ifnet *ifp;
 	int error;
 
 	dev = sc->vtnet_dev;
 	ifp = sc->vtnet_ifp;
 
 	bcopy(IF_LLADDR(ifp), sc->vtnet_hwaddr, ETHER_ADDR_LEN);
 
 	error = vtnet_virtio_reinit(sc);
 	if (error)
 		return (error);
 
 	vtnet_set_macaddr(sc);
 	vtnet_set_active_vq_pairs(sc);
 
 	if (sc->vtnet_flags & VTNET_FLAG_CTRL_VQ)
 		vtnet_init_rx_filters(sc);
 
 	ifp->if_hwassist = 0;
 	if (ifp->if_capenable & IFCAP_TXCSUM)
 		ifp->if_hwassist |= VTNET_CSUM_OFFLOAD;
 	if (ifp->if_capenable & IFCAP_TXCSUM_IPV6)
 		ifp->if_hwassist |= VTNET_CSUM_OFFLOAD_IPV6;
 	if (ifp->if_capenable & IFCAP_TSO4)
 		ifp->if_hwassist |= CSUM_IP_TSO;
 	if (ifp->if_capenable & IFCAP_TSO6)
 		ifp->if_hwassist |= CSUM_IP6_TSO;
 
 	error = vtnet_init_rxtx_queues(sc);
 	if (error)
 		return (error);
 
 	return (0);
 }
 
 static void
 vtnet_init_locked(struct vtnet_softc *sc, int init_mode)
 {
 	device_t dev;
 	struct ifnet *ifp;
 
 	dev = sc->vtnet_dev;
 	ifp = sc->vtnet_ifp;
 
 	VTNET_CORE_LOCK_ASSERT(sc);
 
 	if (ifp->if_drv_flags & IFF_DRV_RUNNING)
 		return;
 
 	vtnet_stop(sc);
 
 #ifdef DEV_NETMAP
 	/* Once stopped we can update the netmap flags, if necessary. */
 	switch (init_mode) {
 	case VTNET_INIT_NETMAP_ENTER:
 		nm_set_native_flags(NA(ifp));
 		break;
 	case VTNET_INIT_NETMAP_EXIT:
 		nm_clear_native_flags(NA(ifp));
 		break;
 	}
 #endif /* DEV_NETMAP */
 
 	if (vtnet_reinit(sc) != 0) {
 		vtnet_stop(sc);
 		return;
 	}
 
 	ifp->if_drv_flags |= IFF_DRV_RUNNING;
 	vtnet_update_link_status(sc);
 	vtnet_enable_interrupts(sc);
 	callout_reset(&sc->vtnet_tick_ch, hz, vtnet_tick, sc);
 
 #ifdef DEV_NETMAP
 	/* Re-enable txsync/rxsync. */
 	netmap_enable_all_rings(ifp);
 #endif /* DEV_NETMAP */
 }
 
 static void
 vtnet_init(void *xsc)
 {
 	struct vtnet_softc *sc;
 
 	sc = xsc;
 
 	VTNET_CORE_LOCK(sc);
 	vtnet_init_locked(sc, 0);
 	VTNET_CORE_UNLOCK(sc);
 }
 
 static void
 vtnet_free_ctrl_vq(struct vtnet_softc *sc)
 {
 
 	/*
 	 * The control virtqueue is only polled and therefore it should
 	 * already be empty.
 	 */
 	KASSERT(virtqueue_empty(sc->vtnet_ctrl_vq),
 	    ("%s: ctrl vq %p not empty", __func__, sc->vtnet_ctrl_vq));
 }
 
 static void
 vtnet_exec_ctrl_cmd(struct vtnet_softc *sc, void *cookie,
     struct sglist *sg, int readable, int writable)
 {
 	struct virtqueue *vq;
 
 	vq = sc->vtnet_ctrl_vq;
 
 	MPASS(sc->vtnet_flags & VTNET_FLAG_CTRL_VQ);
 	VTNET_CORE_LOCK_ASSERT(sc);
 
 	if (!virtqueue_empty(vq))
 		return;
 
 	/*
 	 * Poll for the response, but the command is likely completed before
 	 * returning from the notify.
 	 */
 	if (virtqueue_enqueue(vq, cookie, sg, readable, writable) == 0)  {
 		virtqueue_notify(vq);
 		virtqueue_poll(vq, NULL);
 	}
 }
 
 static int
 vtnet_ctrl_mac_cmd(struct vtnet_softc *sc, uint8_t *hwaddr)
 {
 	struct sglist_seg segs[3];
 	struct sglist sg;
 	struct {
 		struct virtio_net_ctrl_hdr hdr __aligned(2);
 		uint8_t pad1;
 		uint8_t addr[ETHER_ADDR_LEN] __aligned(8);
 		uint8_t pad2;
 		uint8_t ack;
 	} s;
 	int error;
 
 	error = 0;
 	MPASS(sc->vtnet_flags & VTNET_FLAG_CTRL_MAC);
 
 	s.hdr.class = VIRTIO_NET_CTRL_MAC;
 	s.hdr.cmd = VIRTIO_NET_CTRL_MAC_ADDR_SET;
 	bcopy(hwaddr, &s.addr[0], ETHER_ADDR_LEN);
 	s.ack = VIRTIO_NET_ERR;
 
 	sglist_init(&sg, nitems(segs), segs);
 	error |= sglist_append(&sg, &s.hdr, sizeof(struct virtio_net_ctrl_hdr));
 	error |= sglist_append(&sg, &s.addr[0], ETHER_ADDR_LEN);
 	error |= sglist_append(&sg, &s.ack, sizeof(uint8_t));
 	MPASS(error == 0 && sg.sg_nseg == nitems(segs));
 
 	if (error == 0)
 		vtnet_exec_ctrl_cmd(sc, &s.ack, &sg, sg.sg_nseg - 1, 1);
 
 	return (s.ack == VIRTIO_NET_OK ? 0 : EIO);
 }
 
 static int
 vtnet_ctrl_guest_offloads(struct vtnet_softc *sc, uint64_t offloads)
 {
 	struct sglist_seg segs[3];
 	struct sglist sg;
 	struct {
 		struct virtio_net_ctrl_hdr hdr __aligned(2);
 		uint8_t pad1;
 		uint64_t offloads __aligned(8);
 		uint8_t pad2;
 		uint8_t ack;
 	} s;
 	int error;
 
 	error = 0;
 	MPASS(sc->vtnet_features & VIRTIO_NET_F_CTRL_GUEST_OFFLOADS);
 
 	s.hdr.class = VIRTIO_NET_CTRL_GUEST_OFFLOADS;
 	s.hdr.cmd = VIRTIO_NET_CTRL_GUEST_OFFLOADS_SET;
 	s.offloads = vtnet_gtoh64(sc, offloads);
 	s.ack = VIRTIO_NET_ERR;
 
 	sglist_init(&sg, nitems(segs), segs);
 	error |= sglist_append(&sg, &s.hdr, sizeof(struct virtio_net_ctrl_hdr));
 	error |= sglist_append(&sg, &s.offloads, sizeof(uint64_t));
 	error |= sglist_append(&sg, &s.ack, sizeof(uint8_t));
 	MPASS(error == 0 && sg.sg_nseg == nitems(segs));
 
 	if (error == 0)
 		vtnet_exec_ctrl_cmd(sc, &s.ack, &sg, sg.sg_nseg - 1, 1);
 
 	return (s.ack == VIRTIO_NET_OK ? 0 : EIO);
 }
 
 static int
 vtnet_ctrl_mq_cmd(struct vtnet_softc *sc, uint16_t npairs)
 {
 	struct sglist_seg segs[3];
 	struct sglist sg;
 	struct {
 		struct virtio_net_ctrl_hdr hdr __aligned(2);
 		uint8_t pad1;
 		struct virtio_net_ctrl_mq mq __aligned(2);
 		uint8_t pad2;
 		uint8_t ack;
 	} s;
 	int error;
 
 	error = 0;
 	MPASS(sc->vtnet_flags & VTNET_FLAG_MQ);
 
 	s.hdr.class = VIRTIO_NET_CTRL_MQ;
 	s.hdr.cmd = VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET;
 	s.mq.virtqueue_pairs = vtnet_gtoh16(sc, npairs);
 	s.ack = VIRTIO_NET_ERR;
 
 	sglist_init(&sg, nitems(segs), segs);
 	error |= sglist_append(&sg, &s.hdr, sizeof(struct virtio_net_ctrl_hdr));
 	error |= sglist_append(&sg, &s.mq, sizeof(struct virtio_net_ctrl_mq));
 	error |= sglist_append(&sg, &s.ack, sizeof(uint8_t));
 	MPASS(error == 0 && sg.sg_nseg == nitems(segs));
 
 	if (error == 0)
 		vtnet_exec_ctrl_cmd(sc, &s.ack, &sg, sg.sg_nseg - 1, 1);
 
 	return (s.ack == VIRTIO_NET_OK ? 0 : EIO);
 }
 
 static int
 vtnet_ctrl_rx_cmd(struct vtnet_softc *sc, uint8_t cmd, int on)
 {
 	struct sglist_seg segs[3];
 	struct sglist sg;
 	struct {
 		struct virtio_net_ctrl_hdr hdr __aligned(2);
 		uint8_t pad1;
 		uint8_t onoff;
 		uint8_t pad2;
 		uint8_t ack;
 	} s;
 	int error;
 
 	error = 0;
 	MPASS(sc->vtnet_flags & VTNET_FLAG_CTRL_RX);
 
 	s.hdr.class = VIRTIO_NET_CTRL_RX;
 	s.hdr.cmd = cmd;
 	s.onoff = !!on;
 	s.ack = VIRTIO_NET_ERR;
 
 	sglist_init(&sg, nitems(segs), segs);
 	error |= sglist_append(&sg, &s.hdr, sizeof(struct virtio_net_ctrl_hdr));
 	error |= sglist_append(&sg, &s.onoff, sizeof(uint8_t));
 	error |= sglist_append(&sg, &s.ack, sizeof(uint8_t));
 	MPASS(error == 0 && sg.sg_nseg == nitems(segs));
 
 	if (error == 0)
 		vtnet_exec_ctrl_cmd(sc, &s.ack, &sg, sg.sg_nseg - 1, 1);
 
 	return (s.ack == VIRTIO_NET_OK ? 0 : EIO);
 }
 
 static int
 vtnet_set_promisc(struct vtnet_softc *sc, int on)
 {
 	return (vtnet_ctrl_rx_cmd(sc, VIRTIO_NET_CTRL_RX_PROMISC, on));
 }
 
 static int
 vtnet_set_allmulti(struct vtnet_softc *sc, int on)
 {
 	return (vtnet_ctrl_rx_cmd(sc, VIRTIO_NET_CTRL_RX_ALLMULTI, on));
 }
 
 static void
 vtnet_rx_filter(struct vtnet_softc *sc)
 {
 	device_t dev;
 	struct ifnet *ifp;
 
 	dev = sc->vtnet_dev;
 	ifp = sc->vtnet_ifp;
 
 	VTNET_CORE_LOCK_ASSERT(sc);
 
 	if (vtnet_set_promisc(sc, ifp->if_flags & IFF_PROMISC) != 0) {
 		device_printf(dev, "cannot %s promiscuous mode\n",
 		    ifp->if_flags & IFF_PROMISC ? "enable" : "disable");
 	}
 
 	if (vtnet_set_allmulti(sc, ifp->if_flags & IFF_ALLMULTI) != 0) {
 		device_printf(dev, "cannot %s all-multicast mode\n",
 		    ifp->if_flags & IFF_ALLMULTI ? "enable" : "disable");
 	}
 }
 
 static u_int
 vtnet_copy_ifaddr(void *arg, struct sockaddr_dl *sdl, u_int ucnt)
 {
 	struct vtnet_softc *sc = arg;
 
 	if (memcmp(LLADDR(sdl), sc->vtnet_hwaddr, ETHER_ADDR_LEN) == 0)
 		return (0);
 
 	if (ucnt < VTNET_MAX_MAC_ENTRIES)
 		bcopy(LLADDR(sdl),
 		    &sc->vtnet_mac_filter->vmf_unicast.macs[ucnt],
 		    ETHER_ADDR_LEN);
 
 	return (1);
 }
 
 static u_int
 vtnet_copy_maddr(void *arg, struct sockaddr_dl *sdl, u_int mcnt)
 {
 	struct vtnet_mac_filter *filter = arg;
 
 	if (mcnt < VTNET_MAX_MAC_ENTRIES)
 		bcopy(LLADDR(sdl), &filter->vmf_multicast.macs[mcnt],
 		    ETHER_ADDR_LEN);
 
 	return (1);
 }
 
 static void
 vtnet_rx_filter_mac(struct vtnet_softc *sc)
 {
 	struct virtio_net_ctrl_hdr hdr __aligned(2);
 	struct vtnet_mac_filter *filter;
 	struct sglist_seg segs[4];
 	struct sglist sg;
 	struct ifnet *ifp;
 	bool promisc, allmulti;
 	u_int ucnt, mcnt;
 	int error;
 	uint8_t ack;
 
 	ifp = sc->vtnet_ifp;
 	filter = sc->vtnet_mac_filter;
 	error = 0;
 
 	MPASS(sc->vtnet_flags & VTNET_FLAG_CTRL_RX);
 	VTNET_CORE_LOCK_ASSERT(sc);
 
 	/* Unicast MAC addresses: */
 	ucnt = if_foreach_lladdr(ifp, vtnet_copy_ifaddr, sc);
 	promisc = (ucnt > VTNET_MAX_MAC_ENTRIES);
 
 	if (promisc) {
 		ucnt = 0;
 		if_printf(ifp, "more than %d MAC addresses assigned, "
 		    "falling back to promiscuous mode\n",
 		    VTNET_MAX_MAC_ENTRIES);
 	}
 
 	/* Multicast MAC addresses: */
 	mcnt = if_foreach_llmaddr(ifp, vtnet_copy_maddr, filter);
 	allmulti = (mcnt > VTNET_MAX_MAC_ENTRIES);
 
 	if (allmulti) {
 		mcnt = 0;
 		if_printf(ifp, "more than %d multicast MAC addresses "
 		    "assigned, falling back to all-multicast mode\n",
 		    VTNET_MAX_MAC_ENTRIES);
 	}
 
 	if (promisc && allmulti)
 		goto out;
 
 	filter->vmf_unicast.nentries = vtnet_gtoh32(sc, ucnt);
 	filter->vmf_multicast.nentries = vtnet_gtoh32(sc, mcnt);
 
 	hdr.class = VIRTIO_NET_CTRL_MAC;
 	hdr.cmd = VIRTIO_NET_CTRL_MAC_TABLE_SET;
 	ack = VIRTIO_NET_ERR;
 
 	sglist_init(&sg, nitems(segs), segs);
 	error |= sglist_append(&sg, &hdr, sizeof(struct virtio_net_ctrl_hdr));
 	error |= sglist_append(&sg, &filter->vmf_unicast,
 	    sizeof(uint32_t) + ucnt * ETHER_ADDR_LEN);
 	error |= sglist_append(&sg, &filter->vmf_multicast,
 	    sizeof(uint32_t) + mcnt * ETHER_ADDR_LEN);
 	error |= sglist_append(&sg, &ack, sizeof(uint8_t));
 	MPASS(error == 0 && sg.sg_nseg == nitems(segs));
 
 	if (error == 0)
 		vtnet_exec_ctrl_cmd(sc, &ack, &sg, sg.sg_nseg - 1, 1);
 	if (ack != VIRTIO_NET_OK)
 		if_printf(ifp, "error setting host MAC filter table\n");
 
 out:
 	if (promisc != 0 && vtnet_set_promisc(sc, 1) != 0)
 		if_printf(ifp, "cannot enable promiscuous mode\n");
 	if (allmulti != 0 && vtnet_set_allmulti(sc, 1) != 0)
 		if_printf(ifp, "cannot enable all-multicast mode\n");
 }
 
 static int
 vtnet_exec_vlan_filter(struct vtnet_softc *sc, int add, uint16_t tag)
 {
 	struct sglist_seg segs[3];
 	struct sglist sg;
 	struct {
 		struct virtio_net_ctrl_hdr hdr __aligned(2);
 		uint8_t pad1;
 		uint16_t tag __aligned(2);
 		uint8_t pad2;
 		uint8_t ack;
 	} s;
 	int error;
 
 	error = 0;
 	MPASS(sc->vtnet_flags & VTNET_FLAG_VLAN_FILTER);
 
 	s.hdr.class = VIRTIO_NET_CTRL_VLAN;
 	s.hdr.cmd = add ? VIRTIO_NET_CTRL_VLAN_ADD : VIRTIO_NET_CTRL_VLAN_DEL;
 	s.tag = vtnet_gtoh16(sc, tag);
 	s.ack = VIRTIO_NET_ERR;
 
 	sglist_init(&sg, nitems(segs), segs);
 	error |= sglist_append(&sg, &s.hdr, sizeof(struct virtio_net_ctrl_hdr));
 	error |= sglist_append(&sg, &s.tag, sizeof(uint16_t));
 	error |= sglist_append(&sg, &s.ack, sizeof(uint8_t));
 	MPASS(error == 0 && sg.sg_nseg == nitems(segs));
 
 	if (error == 0)
 		vtnet_exec_ctrl_cmd(sc, &s.ack, &sg, sg.sg_nseg - 1, 1);
 
 	return (s.ack == VIRTIO_NET_OK ? 0 : EIO);
 }
 
 static void
 vtnet_rx_filter_vlan(struct vtnet_softc *sc)
 {
 	int i, bit;
 	uint32_t w;
 	uint16_t tag;
 
 	MPASS(sc->vtnet_flags & VTNET_FLAG_VLAN_FILTER);
 	VTNET_CORE_LOCK_ASSERT(sc);
 
 	/* Enable the filter for each configured VLAN. */
 	for (i = 0; i < VTNET_VLAN_FILTER_NWORDS; i++) {
 		w = sc->vtnet_vlan_filter[i];
 
 		while ((bit = ffs(w) - 1) != -1) {
 			w &= ~(1 << bit);
 			tag = sizeof(w) * CHAR_BIT * i + bit;
 
 			if (vtnet_exec_vlan_filter(sc, 1, tag) != 0) {
 				device_printf(sc->vtnet_dev,
 				    "cannot enable VLAN %d filter\n", tag);
 			}
 		}
 	}
 }
 
 static void
 vtnet_update_vlan_filter(struct vtnet_softc *sc, int add, uint16_t tag)
 {
 	struct ifnet *ifp;
 	int idx, bit;
 
 	ifp = sc->vtnet_ifp;
 	idx = (tag >> 5) & 0x7F;
 	bit = tag & 0x1F;
 
 	if (tag == 0 || tag > 4095)
 		return;
 
 	VTNET_CORE_LOCK(sc);
 
 	if (add)
 		sc->vtnet_vlan_filter[idx] |= (1 << bit);
 	else
 		sc->vtnet_vlan_filter[idx] &= ~(1 << bit);
 
 	if (ifp->if_capenable & IFCAP_VLAN_HWFILTER &&
 	    ifp->if_drv_flags & IFF_DRV_RUNNING &&
 	    vtnet_exec_vlan_filter(sc, add, tag) != 0) {
 		device_printf(sc->vtnet_dev,
 		    "cannot %s VLAN %d %s the host filter table\n",
 		    add ? "add" : "remove", tag, add ? "to" : "from");
 	}
 
 	VTNET_CORE_UNLOCK(sc);
 }
 
 static void
 vtnet_register_vlan(void *arg, struct ifnet *ifp, uint16_t tag)
 {
 
 	if (ifp->if_softc != arg)
 		return;
 
 	vtnet_update_vlan_filter(arg, 1, tag);
 }
 
 static void
 vtnet_unregister_vlan(void *arg, struct ifnet *ifp, uint16_t tag)
 {
 
 	if (ifp->if_softc != arg)
 		return;
 
 	vtnet_update_vlan_filter(arg, 0, tag);
 }
 
 static void
 vtnet_update_speed_duplex(struct vtnet_softc *sc)
 {
 	struct ifnet *ifp;
 	uint32_t speed;
 
 	ifp = sc->vtnet_ifp;
 
 	if ((sc->vtnet_features & VIRTIO_NET_F_SPEED_DUPLEX) == 0)
 		return;
 
 	/* BMV: Ignore duplex. */
 	speed = virtio_read_dev_config_4(sc->vtnet_dev,
 	    offsetof(struct virtio_net_config, speed));
 	if (speed != -1)
 		ifp->if_baudrate = IF_Mbps(speed);
 }
 
 static int
 vtnet_is_link_up(struct vtnet_softc *sc)
 {
 	uint16_t status;
 
 	if ((sc->vtnet_features & VIRTIO_NET_F_STATUS) == 0)
 		return (1);
 
 	status = virtio_read_dev_config_2(sc->vtnet_dev,
 	    offsetof(struct virtio_net_config, status));
 
 	return ((status & VIRTIO_NET_S_LINK_UP) != 0);
 }
 
 static void
 vtnet_update_link_status(struct vtnet_softc *sc)
 {
 	struct ifnet *ifp;
 	int link;
 
 	ifp = sc->vtnet_ifp;
 	VTNET_CORE_LOCK_ASSERT(sc);
 	link = vtnet_is_link_up(sc);
 
 	/* Notify if the link status has changed. */
 	if (link != 0 && sc->vtnet_link_active == 0) {
 		vtnet_update_speed_duplex(sc);
 		sc->vtnet_link_active = 1;
 		if_link_state_change(ifp, LINK_STATE_UP);
 	} else if (link == 0 && sc->vtnet_link_active != 0) {
 		sc->vtnet_link_active = 0;
 		if_link_state_change(ifp, LINK_STATE_DOWN);
 	}
 }
 
 static int
 vtnet_ifmedia_upd(struct ifnet *ifp)
 {
 	return (EOPNOTSUPP);
 }
 
 static void
 vtnet_ifmedia_sts(struct ifnet *ifp, struct ifmediareq *ifmr)
 {
 	struct vtnet_softc *sc;
 
 	sc = ifp->if_softc;
 
 	ifmr->ifm_status = IFM_AVALID;
 	ifmr->ifm_active = IFM_ETHER;
 
 	VTNET_CORE_LOCK(sc);
 	if (vtnet_is_link_up(sc) != 0) {
 		ifmr->ifm_status |= IFM_ACTIVE;
 		ifmr->ifm_active |= IFM_10G_T | IFM_FDX;
 	} else
 		ifmr->ifm_active |= IFM_NONE;
 	VTNET_CORE_UNLOCK(sc);
 }
 
 static void
 vtnet_get_macaddr(struct vtnet_softc *sc)
 {
 
 	if (sc->vtnet_flags & VTNET_FLAG_MAC) {
 		virtio_read_device_config_array(sc->vtnet_dev,
 		    offsetof(struct virtio_net_config, mac),
 		    &sc->vtnet_hwaddr[0], sizeof(uint8_t), ETHER_ADDR_LEN);
 	} else {
 		/* Generate a random locally administered unicast address. */
 		sc->vtnet_hwaddr[0] = 0xB2;
 		arc4rand(&sc->vtnet_hwaddr[1], ETHER_ADDR_LEN - 1, 0);
 	}
 }
 
 static void
 vtnet_set_macaddr(struct vtnet_softc *sc)
 {
 	device_t dev;
 	int error;
 
 	dev = sc->vtnet_dev;
 
 	if (sc->vtnet_flags & VTNET_FLAG_CTRL_MAC) {
 		error = vtnet_ctrl_mac_cmd(sc, sc->vtnet_hwaddr);
 		if (error)
 			device_printf(dev, "unable to set MAC address\n");
 		return;
 	}
 
 	/* MAC in config is read-only in modern VirtIO. */
 	if (!vtnet_modern(sc) && sc->vtnet_flags & VTNET_FLAG_MAC) {
 		for (int i = 0; i < ETHER_ADDR_LEN; i++) {
 			virtio_write_dev_config_1(dev,
 			    offsetof(struct virtio_net_config, mac) + i,
 			    sc->vtnet_hwaddr[i]);
 		}
 	}
 }
 
 static void
 vtnet_attached_set_macaddr(struct vtnet_softc *sc)
 {
 
 	/* Assign MAC address if it was generated. */
 	if ((sc->vtnet_flags & VTNET_FLAG_MAC) == 0)
 		vtnet_set_macaddr(sc);
 }
 
 static void
 vtnet_vlan_tag_remove(struct mbuf *m)
 {
 	struct ether_vlan_header *evh;
 
 	evh = mtod(m, struct ether_vlan_header *);
 	m->m_pkthdr.ether_vtag = ntohs(evh->evl_tag);
 	m->m_flags |= M_VLANTAG;
 
 	/* Strip the 802.1Q header. */
 	bcopy((char *) evh, (char *) evh + ETHER_VLAN_ENCAP_LEN,
 	    ETHER_HDR_LEN - ETHER_TYPE_LEN);
 	m_adj(m, ETHER_VLAN_ENCAP_LEN);
 }
 
 static void
 vtnet_set_rx_process_limit(struct vtnet_softc *sc)
 {
 	int limit;
 
 	limit = vtnet_tunable_int(sc, "rx_process_limit",
 	    vtnet_rx_process_limit);
 	if (limit < 0)
 		limit = INT_MAX;
 	sc->vtnet_rx_process_limit = limit;
 }
 
 static void
 vtnet_setup_rxq_sysctl(struct sysctl_ctx_list *ctx,
     struct sysctl_oid_list *child, struct vtnet_rxq *rxq)
 {
 	struct sysctl_oid *node;
 	struct sysctl_oid_list *list;
 	struct vtnet_rxq_stats *stats;
 	char namebuf[16];
 
 	snprintf(namebuf, sizeof(namebuf), "rxq%d", rxq->vtnrx_id);
 	node = SYSCTL_ADD_NODE(ctx, child, OID_AUTO, namebuf,
 	    CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "Receive Queue");
 	list = SYSCTL_CHILDREN(node);
 
 	stats = &rxq->vtnrx_stats;
 
 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "ipackets", CTLFLAG_RD,
 	    &stats->vrxs_ipackets, "Receive packets");
 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "ibytes", CTLFLAG_RD,
 	    &stats->vrxs_ibytes, "Receive bytes");
 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "iqdrops", CTLFLAG_RD,
 	    &stats->vrxs_iqdrops, "Receive drops");
 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "ierrors", CTLFLAG_RD,
 	    &stats->vrxs_ierrors, "Receive errors");
 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "csum", CTLFLAG_RD,
 	    &stats->vrxs_csum, "Receive checksum offloaded");
 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "csum_failed", CTLFLAG_RD,
 	    &stats->vrxs_csum_failed, "Receive checksum offload failed");
 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "rescheduled", CTLFLAG_RD,
 	    &stats->vrxs_rescheduled,
 	    "Receive interrupt handler rescheduled");
 }
 
 static void
 vtnet_setup_txq_sysctl(struct sysctl_ctx_list *ctx,
     struct sysctl_oid_list *child, struct vtnet_txq *txq)
 {
 	struct sysctl_oid *node;
 	struct sysctl_oid_list *list;
 	struct vtnet_txq_stats *stats;
 	char namebuf[16];
 
 	snprintf(namebuf, sizeof(namebuf), "txq%d", txq->vtntx_id);
 	node = SYSCTL_ADD_NODE(ctx, child, OID_AUTO, namebuf,
 	    CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "Transmit Queue");
 	list = SYSCTL_CHILDREN(node);
 
 	stats = &txq->vtntx_stats;
 
 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "opackets", CTLFLAG_RD,
 	    &stats->vtxs_opackets, "Transmit packets");
 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "obytes", CTLFLAG_RD,
 	    &stats->vtxs_obytes, "Transmit bytes");
 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "omcasts", CTLFLAG_RD,
 	    &stats->vtxs_omcasts, "Transmit multicasts");
 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "csum", CTLFLAG_RD,
 	    &stats->vtxs_csum, "Transmit checksum offloaded");
 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "tso", CTLFLAG_RD,
 	    &stats->vtxs_tso, "Transmit segmentation offloaded");
 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "rescheduled", CTLFLAG_RD,
 	    &stats->vtxs_rescheduled,
 	    "Transmit interrupt handler rescheduled");
 }
 
 static void
 vtnet_setup_queue_sysctl(struct vtnet_softc *sc)
 {
 	device_t dev;
 	struct sysctl_ctx_list *ctx;
 	struct sysctl_oid *tree;
 	struct sysctl_oid_list *child;
 	int i;
 
 	dev = sc->vtnet_dev;
 	ctx = device_get_sysctl_ctx(dev);
 	tree = device_get_sysctl_tree(dev);
 	child = SYSCTL_CHILDREN(tree);
 
 	for (i = 0; i < sc->vtnet_req_vq_pairs; i++) {
 		vtnet_setup_rxq_sysctl(ctx, child, &sc->vtnet_rxqs[i]);
 		vtnet_setup_txq_sysctl(ctx, child, &sc->vtnet_txqs[i]);
 	}
 }
 
 static void
 vtnet_setup_stat_sysctl(struct sysctl_ctx_list *ctx,
     struct sysctl_oid_list *child, struct vtnet_softc *sc)
 {
 	struct vtnet_statistics *stats;
 	struct vtnet_rxq_stats rxaccum;
 	struct vtnet_txq_stats txaccum;
 
 	vtnet_accum_stats(sc, &rxaccum, &txaccum);
 
 	stats = &sc->vtnet_stats;
 	stats->rx_csum_offloaded = rxaccum.vrxs_csum;
 	stats->rx_csum_failed = rxaccum.vrxs_csum_failed;
 	stats->rx_task_rescheduled = rxaccum.vrxs_rescheduled;
 	stats->tx_csum_offloaded = txaccum.vtxs_csum;
 	stats->tx_tso_offloaded = txaccum.vtxs_tso;
 	stats->tx_task_rescheduled = txaccum.vtxs_rescheduled;
 
 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "mbuf_alloc_failed",
 	    CTLFLAG_RD, &stats->mbuf_alloc_failed,
 	    "Mbuf cluster allocation failures");
 
 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "rx_frame_too_large",
 	    CTLFLAG_RD, &stats->rx_frame_too_large,
 	    "Received frame larger than the mbuf chain");
 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "rx_enq_replacement_failed",
 	    CTLFLAG_RD, &stats->rx_enq_replacement_failed,
 	    "Enqueuing the replacement receive mbuf failed");
 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "rx_mergeable_failed",
 	    CTLFLAG_RD, &stats->rx_mergeable_failed,
 	    "Mergeable buffers receive failures");
 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "rx_csum_bad_ethtype",
 	    CTLFLAG_RD, &stats->rx_csum_bad_ethtype,
 	    "Received checksum offloaded buffer with unsupported "
 	    "Ethernet type");
 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "rx_csum_bad_ipproto",
 	    CTLFLAG_RD, &stats->rx_csum_bad_ipproto,
 	    "Received checksum offloaded buffer with incorrect IP protocol");
 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "rx_csum_bad_offset",
 	    CTLFLAG_RD, &stats->rx_csum_bad_offset,
 	    "Received checksum offloaded buffer with incorrect offset");
 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "rx_csum_bad_proto",
 	    CTLFLAG_RD, &stats->rx_csum_bad_proto,
 	    "Received checksum offloaded buffer with incorrect protocol");
 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "rx_csum_failed",
 	    CTLFLAG_RD, &stats->rx_csum_failed,
 	    "Received buffer checksum offload failed");
 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "rx_csum_offloaded",
 	    CTLFLAG_RD, &stats->rx_csum_offloaded,
 	    "Received buffer checksum offload succeeded");
 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "rx_task_rescheduled",
 	    CTLFLAG_RD, &stats->rx_task_rescheduled,
 	    "Times the receive interrupt task rescheduled itself");
 
 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "tx_csum_bad_ethtype",
 	    CTLFLAG_RD, &stats->tx_csum_bad_ethtype,
 	    "Aborted transmit of checksum offloaded buffer with unknown "
 	    "Ethernet type");
 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "tx_tso_bad_ethtype",
 	    CTLFLAG_RD, &stats->tx_tso_bad_ethtype,
 	    "Aborted transmit of TSO buffer with unknown Ethernet type");
 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "tx_tso_not_tcp",
 	    CTLFLAG_RD, &stats->tx_tso_not_tcp,
 	    "Aborted transmit of TSO buffer with non TCP protocol");
 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "tx_defragged",
 	    CTLFLAG_RD, &stats->tx_defragged,
 	    "Transmit mbufs defragged");
 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "tx_defrag_failed",
 	    CTLFLAG_RD, &stats->tx_defrag_failed,
 	    "Aborted transmit of buffer because defrag failed");
 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "tx_csum_offloaded",
 	    CTLFLAG_RD, &stats->tx_csum_offloaded,
 	    "Offloaded checksum of transmitted buffer");
 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "tx_tso_offloaded",
 	    CTLFLAG_RD, &stats->tx_tso_offloaded,
 	    "Segmentation offload of transmitted buffer");
 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "tx_task_rescheduled",
 	    CTLFLAG_RD, &stats->tx_task_rescheduled,
 	    "Times the transmit interrupt task rescheduled itself");
 }
 
 static void
 vtnet_setup_sysctl(struct vtnet_softc *sc)
 {
 	device_t dev;
 	struct sysctl_ctx_list *ctx;
 	struct sysctl_oid *tree;
 	struct sysctl_oid_list *child;
 
 	dev = sc->vtnet_dev;
 	ctx = device_get_sysctl_ctx(dev);
 	tree = device_get_sysctl_tree(dev);
 	child = SYSCTL_CHILDREN(tree);
 
 	SYSCTL_ADD_INT(ctx, child, OID_AUTO, "max_vq_pairs",
 	    CTLFLAG_RD, &sc->vtnet_max_vq_pairs, 0,
 	    "Number of maximum supported virtqueue pairs");
 	SYSCTL_ADD_INT(ctx, child, OID_AUTO, "req_vq_pairs",
 	    CTLFLAG_RD, &sc->vtnet_req_vq_pairs, 0,
 	    "Number of requested virtqueue pairs");
 	SYSCTL_ADD_INT(ctx, child, OID_AUTO, "act_vq_pairs",
 	    CTLFLAG_RD, &sc->vtnet_act_vq_pairs, 0,
 	    "Number of active virtqueue pairs");
 
 	vtnet_setup_stat_sysctl(ctx, child, sc);
 }
 
 static void
 vtnet_load_tunables(struct vtnet_softc *sc)
 {
 
 	sc->vtnet_lro_entry_count = vtnet_tunable_int(sc,
 	    "lro_entry_count", vtnet_lro_entry_count);
 	if (sc->vtnet_lro_entry_count < TCP_LRO_ENTRIES)
 		sc->vtnet_lro_entry_count = TCP_LRO_ENTRIES;
 
 	sc->vtnet_lro_mbufq_depth = vtnet_tunable_int(sc,
 	    "lro_mbufq_depth", vtnet_lro_mbufq_depth);
 }
 
 static int
 vtnet_rxq_enable_intr(struct vtnet_rxq *rxq)
 {
 
 	return (virtqueue_enable_intr(rxq->vtnrx_vq));
 }
 
 static void
 vtnet_rxq_disable_intr(struct vtnet_rxq *rxq)
 {
 
 	virtqueue_disable_intr(rxq->vtnrx_vq);
 }
 
 static int
 vtnet_txq_enable_intr(struct vtnet_txq *txq)
 {
 	struct virtqueue *vq;
 
 	vq = txq->vtntx_vq;
 
 	if (vtnet_txq_below_threshold(txq) != 0)
 		return (virtqueue_postpone_intr(vq, VQ_POSTPONE_LONG));
 
 	/*
 	 * The free count is above our threshold. Keep the Tx interrupt
 	 * disabled until the queue is fuller.
 	 */
 	return (0);
 }
 
 static void
 vtnet_txq_disable_intr(struct vtnet_txq *txq)
 {
 
 	virtqueue_disable_intr(txq->vtntx_vq);
 }
 
 static void
 vtnet_enable_rx_interrupts(struct vtnet_softc *sc)
 {
+	struct vtnet_rxq *rxq;
 	int i;
 
-	for (i = 0; i < sc->vtnet_act_vq_pairs; i++)
-		vtnet_rxq_enable_intr(&sc->vtnet_rxqs[i]);
+	for (i = 0; i < sc->vtnet_act_vq_pairs; i++) {
+		rxq = &sc->vtnet_rxqs[i];
+		if (vtnet_rxq_enable_intr(rxq) != 0)
+			taskqueue_enqueue(rxq->vtnrx_tq, &rxq->vtnrx_intrtask);
+	}
 }
 
 static void
 vtnet_enable_tx_interrupts(struct vtnet_softc *sc)
 {
 	int i;
 
 	for (i = 0; i < sc->vtnet_act_vq_pairs; i++)
 		vtnet_txq_enable_intr(&sc->vtnet_txqs[i]);
 }
 
 static void
 vtnet_enable_interrupts(struct vtnet_softc *sc)
 {
 
 	vtnet_enable_rx_interrupts(sc);
 	vtnet_enable_tx_interrupts(sc);
 }
 
 static void
 vtnet_disable_rx_interrupts(struct vtnet_softc *sc)
 {
 	int i;
 
 	for (i = 0; i < sc->vtnet_max_vq_pairs; i++)
 		vtnet_rxq_disable_intr(&sc->vtnet_rxqs[i]);
 }
 
 static void
 vtnet_disable_tx_interrupts(struct vtnet_softc *sc)
 {
 	int i;
 
 	for (i = 0; i < sc->vtnet_max_vq_pairs; i++)
 		vtnet_txq_disable_intr(&sc->vtnet_txqs[i]);
 }
 
 static void
 vtnet_disable_interrupts(struct vtnet_softc *sc)
 {
 
 	vtnet_disable_rx_interrupts(sc);
 	vtnet_disable_tx_interrupts(sc);
 }
 
 static int
 vtnet_tunable_int(struct vtnet_softc *sc, const char *knob, int def)
 {
 	char path[64];
 
 	snprintf(path, sizeof(path),
 	    "hw.vtnet.%d.%s", device_get_unit(sc->vtnet_dev), knob);
 	TUNABLE_INT_FETCH(path, &def);
 
 	return (def);
 }
 
 #ifdef DEBUGNET
 static void
 vtnet_debugnet_init(struct ifnet *ifp, int *nrxr, int *ncl, int *clsize)
 {
 	struct vtnet_softc *sc;
 
 	sc = if_getsoftc(ifp);
 
 	VTNET_CORE_LOCK(sc);
 	*nrxr = sc->vtnet_req_vq_pairs;
 	*ncl = DEBUGNET_MAX_IN_FLIGHT;
 	*clsize = sc->vtnet_rx_clustersz;
 	VTNET_CORE_UNLOCK(sc);
 }
 
 static void
 vtnet_debugnet_event(struct ifnet *ifp __unused, enum debugnet_ev event __unused)
 {
 }
 
 static int
 vtnet_debugnet_transmit(struct ifnet *ifp, struct mbuf *m)
 {
 	struct vtnet_softc *sc;
 	struct vtnet_txq *txq;
 	int error;
 
 	sc = if_getsoftc(ifp);
 	if ((if_getdrvflags(ifp) & (IFF_DRV_RUNNING | IFF_DRV_OACTIVE)) !=
 	    IFF_DRV_RUNNING)
 		return (EBUSY);
 
 	txq = &sc->vtnet_txqs[0];
 	error = vtnet_txq_encap(txq, &m, M_NOWAIT | M_USE_RESERVE);
 	if (error == 0)
 		(void)vtnet_txq_notify(txq);
 	return (error);
 }
 
 static int
 vtnet_debugnet_poll(struct ifnet *ifp, int count)
 {
 	struct vtnet_softc *sc;
 	int i;
 
 	sc = if_getsoftc(ifp);
 	if ((if_getdrvflags(ifp) & (IFF_DRV_RUNNING | IFF_DRV_OACTIVE)) !=
 	    IFF_DRV_RUNNING)
 		return (EBUSY);
 
 	(void)vtnet_txq_eof(&sc->vtnet_txqs[0]);
 	for (i = 0; i < sc->vtnet_act_vq_pairs; i++)
 		(void)vtnet_rxq_eof(&sc->vtnet_rxqs[i]);
 	return (0);
 }
 #endif /* DEBUGNET */