xref: /freebsd/sys/dev/virtio/network/if_vtnet.c (revision 130d950cafcd29c6a32cf5357bf600dcd9c1d998)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2011, Bryan Venteicher <bryanv@FreeBSD.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice unmodified, this list of conditions, and the following
12  *    disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 /* Driver for VirtIO network devices. */
30 
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
33 
34 #include <sys/param.h>
35 #include <sys/eventhandler.h>
36 #include <sys/systm.h>
37 #include <sys/kernel.h>
38 #include <sys/sockio.h>
39 #include <sys/mbuf.h>
40 #include <sys/malloc.h>
41 #include <sys/module.h>
42 #include <sys/socket.h>
43 #include <sys/sysctl.h>
44 #include <sys/random.h>
45 #include <sys/sglist.h>
46 #include <sys/lock.h>
47 #include <sys/mutex.h>
48 #include <sys/taskqueue.h>
49 #include <sys/smp.h>
50 #include <machine/smp.h>
51 
52 #include <vm/uma.h>
53 
54 #include <net/debugnet.h>
55 #include <net/ethernet.h>
56 #include <net/pfil.h>
57 #include <net/if.h>
58 #include <net/if_var.h>
59 #include <net/if_arp.h>
60 #include <net/if_dl.h>
61 #include <net/if_types.h>
62 #include <net/if_media.h>
63 #include <net/if_vlan_var.h>
64 
65 #include <net/bpf.h>
66 
67 #include <netinet/in_systm.h>
68 #include <netinet/in.h>
69 #include <netinet/ip.h>
70 #include <netinet/ip6.h>
71 #include <netinet6/ip6_var.h>
72 #include <netinet/udp.h>
73 #include <netinet/tcp.h>
74 
75 #include <machine/bus.h>
76 #include <machine/resource.h>
77 #include <sys/bus.h>
78 #include <sys/rman.h>
79 
80 #include <dev/virtio/virtio.h>
81 #include <dev/virtio/virtqueue.h>
82 #include <dev/virtio/network/virtio_net.h>
83 #include <dev/virtio/network/if_vtnetvar.h>
84 #include "virtio_if.h"
85 
86 #include "opt_inet.h"
87 #include "opt_inet6.h"
88 
89 static int	vtnet_modevent(module_t, int, void *);
90 
91 static int	vtnet_probe(device_t);
92 static int	vtnet_attach(device_t);
93 static int	vtnet_detach(device_t);
94 static int	vtnet_suspend(device_t);
95 static int	vtnet_resume(device_t);
96 static int	vtnet_shutdown(device_t);
97 static int	vtnet_attach_completed(device_t);
98 static int	vtnet_config_change(device_t);
99 
100 static void	vtnet_negotiate_features(struct vtnet_softc *);
101 static void	vtnet_setup_features(struct vtnet_softc *);
102 static int	vtnet_init_rxq(struct vtnet_softc *, int);
103 static int	vtnet_init_txq(struct vtnet_softc *, int);
104 static int	vtnet_alloc_rxtx_queues(struct vtnet_softc *);
105 static void	vtnet_free_rxtx_queues(struct vtnet_softc *);
106 static int	vtnet_alloc_rx_filters(struct vtnet_softc *);
107 static void	vtnet_free_rx_filters(struct vtnet_softc *);
108 static int	vtnet_alloc_virtqueues(struct vtnet_softc *);
109 static int	vtnet_setup_interface(struct vtnet_softc *);
110 static int	vtnet_change_mtu(struct vtnet_softc *, int);
111 static int	vtnet_ioctl(struct ifnet *, u_long, caddr_t);
112 static uint64_t	vtnet_get_counter(struct ifnet *, ift_counter);
113 
114 static int	vtnet_rxq_populate(struct vtnet_rxq *);
115 static void	vtnet_rxq_free_mbufs(struct vtnet_rxq *);
116 static struct mbuf *
117 		vtnet_rx_alloc_buf(struct vtnet_softc *, int , struct mbuf **);
118 static int	vtnet_rxq_replace_lro_nomgr_buf(struct vtnet_rxq *,
119 		    struct mbuf *, int);
120 static int	vtnet_rxq_replace_buf(struct vtnet_rxq *, struct mbuf *, int);
121 static int	vtnet_rxq_enqueue_buf(struct vtnet_rxq *, struct mbuf *);
122 static int	vtnet_rxq_new_buf(struct vtnet_rxq *);
123 static int	vtnet_rxq_csum(struct vtnet_rxq *, struct mbuf *,
124 		     struct virtio_net_hdr *);
125 static void	vtnet_rxq_discard_merged_bufs(struct vtnet_rxq *, int);
126 static void	vtnet_rxq_discard_buf(struct vtnet_rxq *, struct mbuf *);
127 static int	vtnet_rxq_merged_eof(struct vtnet_rxq *, struct mbuf *, int);
128 static void	vtnet_rxq_input(struct vtnet_rxq *, struct mbuf *,
129 		    struct virtio_net_hdr *);
130 static int	vtnet_rxq_eof(struct vtnet_rxq *);
131 static void	vtnet_rx_vq_intr(void *);
132 static void	vtnet_rxq_tq_intr(void *, int);
133 
134 static int	vtnet_txq_below_threshold(struct vtnet_txq *);
135 static int	vtnet_txq_notify(struct vtnet_txq *);
136 static void	vtnet_txq_free_mbufs(struct vtnet_txq *);
137 static int	vtnet_txq_offload_ctx(struct vtnet_txq *, struct mbuf *,
138 		    int *, int *, int *);
139 static int	vtnet_txq_offload_tso(struct vtnet_txq *, struct mbuf *, int,
140 		    int, struct virtio_net_hdr *);
141 static struct mbuf *
142 		vtnet_txq_offload(struct vtnet_txq *, struct mbuf *,
143 		    struct virtio_net_hdr *);
144 static int	vtnet_txq_enqueue_buf(struct vtnet_txq *, struct mbuf **,
145 		    struct vtnet_tx_header *);
146 static int	vtnet_txq_encap(struct vtnet_txq *, struct mbuf **, int);
147 #ifdef VTNET_LEGACY_TX
148 static void	vtnet_start_locked(struct vtnet_txq *, struct ifnet *);
149 static void	vtnet_start(struct ifnet *);
150 #else
151 static int	vtnet_txq_mq_start_locked(struct vtnet_txq *, struct mbuf *);
152 static int	vtnet_txq_mq_start(struct ifnet *, struct mbuf *);
153 static void	vtnet_txq_tq_deferred(void *, int);
154 #endif
155 static void	vtnet_txq_start(struct vtnet_txq *);
156 static void	vtnet_txq_tq_intr(void *, int);
157 static int	vtnet_txq_eof(struct vtnet_txq *);
158 static void	vtnet_tx_vq_intr(void *);
159 static void	vtnet_tx_start_all(struct vtnet_softc *);
160 
161 #ifndef VTNET_LEGACY_TX
162 static void	vtnet_qflush(struct ifnet *);
163 #endif
164 
165 static int	vtnet_watchdog(struct vtnet_txq *);
166 static void	vtnet_accum_stats(struct vtnet_softc *,
167 		    struct vtnet_rxq_stats *, struct vtnet_txq_stats *);
168 static void	vtnet_tick(void *);
169 
170 static void	vtnet_start_taskqueues(struct vtnet_softc *);
171 static void	vtnet_free_taskqueues(struct vtnet_softc *);
172 static void	vtnet_drain_taskqueues(struct vtnet_softc *);
173 
174 static void	vtnet_drain_rxtx_queues(struct vtnet_softc *);
175 static void	vtnet_stop_rendezvous(struct vtnet_softc *);
176 static void	vtnet_stop(struct vtnet_softc *);
177 static int	vtnet_virtio_reinit(struct vtnet_softc *);
178 static void	vtnet_init_rx_filters(struct vtnet_softc *);
179 static int	vtnet_init_rx_queues(struct vtnet_softc *);
180 static int	vtnet_init_tx_queues(struct vtnet_softc *);
181 static int	vtnet_init_rxtx_queues(struct vtnet_softc *);
182 static void	vtnet_set_active_vq_pairs(struct vtnet_softc *);
183 static int	vtnet_reinit(struct vtnet_softc *);
184 static void	vtnet_init_locked(struct vtnet_softc *);
185 static void	vtnet_init(void *);
186 
187 static void	vtnet_free_ctrl_vq(struct vtnet_softc *);
188 static void	vtnet_exec_ctrl_cmd(struct vtnet_softc *, void *,
189 		    struct sglist *, int, int);
190 static int	vtnet_ctrl_mac_cmd(struct vtnet_softc *, uint8_t *);
191 static int	vtnet_ctrl_mq_cmd(struct vtnet_softc *, uint16_t);
192 static int	vtnet_ctrl_rx_cmd(struct vtnet_softc *, int, int);
193 static int	vtnet_set_promisc(struct vtnet_softc *, int);
194 static int	vtnet_set_allmulti(struct vtnet_softc *, int);
195 static void	vtnet_attach_disable_promisc(struct vtnet_softc *);
196 static void	vtnet_rx_filter(struct vtnet_softc *);
197 static void	vtnet_rx_filter_mac(struct vtnet_softc *);
198 static int	vtnet_exec_vlan_filter(struct vtnet_softc *, int, uint16_t);
199 static void	vtnet_rx_filter_vlan(struct vtnet_softc *);
200 static void	vtnet_update_vlan_filter(struct vtnet_softc *, int, uint16_t);
201 static void	vtnet_register_vlan(void *, struct ifnet *, uint16_t);
202 static void	vtnet_unregister_vlan(void *, struct ifnet *, uint16_t);
203 
204 static int	vtnet_is_link_up(struct vtnet_softc *);
205 static void	vtnet_update_link_status(struct vtnet_softc *);
206 static int	vtnet_ifmedia_upd(struct ifnet *);
207 static void	vtnet_ifmedia_sts(struct ifnet *, struct ifmediareq *);
208 static void	vtnet_get_hwaddr(struct vtnet_softc *);
209 static void	vtnet_set_hwaddr(struct vtnet_softc *);
210 static void	vtnet_vlan_tag_remove(struct mbuf *);
211 static void	vtnet_set_rx_process_limit(struct vtnet_softc *);
212 static void	vtnet_set_tx_intr_threshold(struct vtnet_softc *);
213 
214 static void	vtnet_setup_rxq_sysctl(struct sysctl_ctx_list *,
215 		    struct sysctl_oid_list *, struct vtnet_rxq *);
216 static void	vtnet_setup_txq_sysctl(struct sysctl_ctx_list *,
217 		    struct sysctl_oid_list *, struct vtnet_txq *);
218 static void	vtnet_setup_queue_sysctl(struct vtnet_softc *);
219 static void	vtnet_setup_sysctl(struct vtnet_softc *);
220 
221 static int	vtnet_rxq_enable_intr(struct vtnet_rxq *);
222 static void	vtnet_rxq_disable_intr(struct vtnet_rxq *);
223 static int	vtnet_txq_enable_intr(struct vtnet_txq *);
224 static void	vtnet_txq_disable_intr(struct vtnet_txq *);
225 static void	vtnet_enable_rx_interrupts(struct vtnet_softc *);
226 static void	vtnet_enable_tx_interrupts(struct vtnet_softc *);
227 static void	vtnet_enable_interrupts(struct vtnet_softc *);
228 static void	vtnet_disable_rx_interrupts(struct vtnet_softc *);
229 static void	vtnet_disable_tx_interrupts(struct vtnet_softc *);
230 static void	vtnet_disable_interrupts(struct vtnet_softc *);
231 
232 static int	vtnet_tunable_int(struct vtnet_softc *, const char *, int);
233 
234 DEBUGNET_DEFINE(vtnet);
235 
236 /* Tunables. */
237 static SYSCTL_NODE(_hw, OID_AUTO, vtnet, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
238     "VNET driver parameters");
239 static int vtnet_csum_disable = 0;
240 TUNABLE_INT("hw.vtnet.csum_disable", &vtnet_csum_disable);
241 SYSCTL_INT(_hw_vtnet, OID_AUTO, csum_disable, CTLFLAG_RDTUN,
242     &vtnet_csum_disable, 0, "Disables receive and send checksum offload");
243 static int vtnet_tso_disable = 0;
244 TUNABLE_INT("hw.vtnet.tso_disable", &vtnet_tso_disable);
245 SYSCTL_INT(_hw_vtnet, OID_AUTO, tso_disable, CTLFLAG_RDTUN, &vtnet_tso_disable,
246     0, "Disables TCP Segmentation Offload");
247 static int vtnet_lro_disable = 0;
248 TUNABLE_INT("hw.vtnet.lro_disable", &vtnet_lro_disable);
249 SYSCTL_INT(_hw_vtnet, OID_AUTO, lro_disable, CTLFLAG_RDTUN, &vtnet_lro_disable,
250     0, "Disables TCP Large Receive Offload");
251 static int vtnet_mq_disable = 0;
252 TUNABLE_INT("hw.vtnet.mq_disable", &vtnet_mq_disable);
253 SYSCTL_INT(_hw_vtnet, OID_AUTO, mq_disable, CTLFLAG_RDTUN, &vtnet_mq_disable,
254     0, "Disables Multi Queue support");
255 static int vtnet_mq_max_pairs = VTNET_MAX_QUEUE_PAIRS;
256 TUNABLE_INT("hw.vtnet.mq_max_pairs", &vtnet_mq_max_pairs);
257 SYSCTL_INT(_hw_vtnet, OID_AUTO, mq_max_pairs, CTLFLAG_RDTUN,
258     &vtnet_mq_max_pairs, 0, "Sets the maximum number of Multi Queue pairs");
259 static int vtnet_rx_process_limit = 512;
260 TUNABLE_INT("hw.vtnet.rx_process_limit", &vtnet_rx_process_limit);
261 SYSCTL_INT(_hw_vtnet, OID_AUTO, rx_process_limit, CTLFLAG_RDTUN,
262     &vtnet_rx_process_limit, 0,
263     "Limits the number RX segments processed in a single pass");
264 
265 static uma_zone_t vtnet_tx_header_zone;
266 
267 static struct virtio_feature_desc vtnet_feature_desc[] = {
268 	{ VIRTIO_NET_F_CSUM,		"TxChecksum"	},
269 	{ VIRTIO_NET_F_GUEST_CSUM,	"RxChecksum"	},
270 	{ VIRTIO_NET_F_MAC,		"MacAddress"	},
271 	{ VIRTIO_NET_F_GSO,		"TxAllGSO"	},
272 	{ VIRTIO_NET_F_GUEST_TSO4,	"RxTSOv4"	},
273 	{ VIRTIO_NET_F_GUEST_TSO6,	"RxTSOv6"	},
274 	{ VIRTIO_NET_F_GUEST_ECN,	"RxECN"		},
275 	{ VIRTIO_NET_F_GUEST_UFO,	"RxUFO"		},
276 	{ VIRTIO_NET_F_HOST_TSO4,	"TxTSOv4"	},
277 	{ VIRTIO_NET_F_HOST_TSO6,	"TxTSOv6"	},
278 	{ VIRTIO_NET_F_HOST_ECN,	"TxTSOECN"	},
279 	{ VIRTIO_NET_F_HOST_UFO,	"TxUFO"		},
280 	{ VIRTIO_NET_F_MRG_RXBUF,	"MrgRxBuf"	},
281 	{ VIRTIO_NET_F_STATUS,		"Status"	},
282 	{ VIRTIO_NET_F_CTRL_VQ,		"ControlVq"	},
283 	{ VIRTIO_NET_F_CTRL_RX,		"RxMode"	},
284 	{ VIRTIO_NET_F_CTRL_VLAN,	"VLanFilter"	},
285 	{ VIRTIO_NET_F_CTRL_RX_EXTRA,	"RxModeExtra"	},
286 	{ VIRTIO_NET_F_GUEST_ANNOUNCE,	"GuestAnnounce"	},
287 	{ VIRTIO_NET_F_MQ,		"Multiqueue"	},
288 	{ VIRTIO_NET_F_CTRL_MAC_ADDR,	"SetMacAddress"	},
289 
290 	{ 0, NULL }
291 };
292 
293 static device_method_t vtnet_methods[] = {
294 	/* Device methods. */
295 	DEVMETHOD(device_probe,			vtnet_probe),
296 	DEVMETHOD(device_attach,		vtnet_attach),
297 	DEVMETHOD(device_detach,		vtnet_detach),
298 	DEVMETHOD(device_suspend,		vtnet_suspend),
299 	DEVMETHOD(device_resume,		vtnet_resume),
300 	DEVMETHOD(device_shutdown,		vtnet_shutdown),
301 
302 	/* VirtIO methods. */
303 	DEVMETHOD(virtio_attach_completed,	vtnet_attach_completed),
304 	DEVMETHOD(virtio_config_change,		vtnet_config_change),
305 
306 	DEVMETHOD_END
307 };
308 
309 #ifdef DEV_NETMAP
310 #include <dev/netmap/if_vtnet_netmap.h>
311 #endif /* DEV_NETMAP */
312 
313 static driver_t vtnet_driver = {
314 	"vtnet",
315 	vtnet_methods,
316 	sizeof(struct vtnet_softc)
317 };
318 static devclass_t vtnet_devclass;
319 
320 DRIVER_MODULE(vtnet, virtio_mmio, vtnet_driver, vtnet_devclass,
321     vtnet_modevent, 0);
322 DRIVER_MODULE(vtnet, virtio_pci, vtnet_driver, vtnet_devclass,
323     vtnet_modevent, 0);
324 MODULE_VERSION(vtnet, 1);
325 MODULE_DEPEND(vtnet, virtio, 1, 1, 1);
326 #ifdef DEV_NETMAP
327 MODULE_DEPEND(vtnet, netmap, 1, 1, 1);
328 #endif /* DEV_NETMAP */
329 
330 VIRTIO_SIMPLE_PNPTABLE(vtnet, VIRTIO_ID_NETWORK, "VirtIO Networking Adapter");
331 VIRTIO_SIMPLE_PNPINFO(virtio_mmio, vtnet);
332 VIRTIO_SIMPLE_PNPINFO(virtio_pci, vtnet);
333 
334 static int
335 vtnet_modevent(module_t mod, int type, void *unused)
336 {
337 	int error = 0;
338 	static int loaded = 0;
339 
340 	switch (type) {
341 	case MOD_LOAD:
342 		if (loaded++ == 0) {
343 			vtnet_tx_header_zone = uma_zcreate("vtnet_tx_hdr",
344 				sizeof(struct vtnet_tx_header),
345 				NULL, NULL, NULL, NULL, 0, 0);
346 #ifdef DEBUGNET
347 			/*
348 			 * We need to allocate from this zone in the transmit path, so ensure
349 			 * that we have at least one item per header available.
350 			 * XXX add a separate zone like we do for mbufs? otherwise we may alloc
351 			 * buckets
352 			 */
353 			uma_zone_reserve(vtnet_tx_header_zone, DEBUGNET_MAX_IN_FLIGHT * 2);
354 			uma_prealloc(vtnet_tx_header_zone, DEBUGNET_MAX_IN_FLIGHT * 2);
355 #endif
356 		}
357 		break;
358 	case MOD_QUIESCE:
359 		if (uma_zone_get_cur(vtnet_tx_header_zone) > 0)
360 			error = EBUSY;
361 		break;
362 	case MOD_UNLOAD:
363 		if (--loaded == 0) {
364 			uma_zdestroy(vtnet_tx_header_zone);
365 			vtnet_tx_header_zone = NULL;
366 		}
367 		break;
368 	case MOD_SHUTDOWN:
369 		break;
370 	default:
371 		error = EOPNOTSUPP;
372 		break;
373 	}
374 
375 	return (error);
376 }
377 
378 static int
379 vtnet_probe(device_t dev)
380 {
381 	return (VIRTIO_SIMPLE_PROBE(dev, vtnet));
382 }
383 
384 static int
385 vtnet_attach(device_t dev)
386 {
387 	struct vtnet_softc *sc;
388 	int error;
389 
390 	sc = device_get_softc(dev);
391 	sc->vtnet_dev = dev;
392 
393 	/* Register our feature descriptions. */
394 	virtio_set_feature_desc(dev, vtnet_feature_desc);
395 
396 	VTNET_CORE_LOCK_INIT(sc);
397 	callout_init_mtx(&sc->vtnet_tick_ch, VTNET_CORE_MTX(sc), 0);
398 
399 	vtnet_setup_sysctl(sc);
400 	vtnet_setup_features(sc);
401 
402 	error = vtnet_alloc_rx_filters(sc);
403 	if (error) {
404 		device_printf(dev, "cannot allocate Rx filters\n");
405 		goto fail;
406 	}
407 
408 	error = vtnet_alloc_rxtx_queues(sc);
409 	if (error) {
410 		device_printf(dev, "cannot allocate queues\n");
411 		goto fail;
412 	}
413 
414 	error = vtnet_alloc_virtqueues(sc);
415 	if (error) {
416 		device_printf(dev, "cannot allocate virtqueues\n");
417 		goto fail;
418 	}
419 
420 	error = vtnet_setup_interface(sc);
421 	if (error) {
422 		device_printf(dev, "cannot setup interface\n");
423 		goto fail;
424 	}
425 
426 	error = virtio_setup_intr(dev, INTR_TYPE_NET);
427 	if (error) {
428 		device_printf(dev, "cannot setup virtqueue interrupts\n");
429 		/* BMV: This will crash if during boot! */
430 		ether_ifdetach(sc->vtnet_ifp);
431 		goto fail;
432 	}
433 
434 #ifdef DEV_NETMAP
435 	vtnet_netmap_attach(sc);
436 #endif /* DEV_NETMAP */
437 
438 	vtnet_start_taskqueues(sc);
439 
440 fail:
441 	if (error)
442 		vtnet_detach(dev);
443 
444 	return (error);
445 }
446 
447 static int
448 vtnet_detach(device_t dev)
449 {
450 	struct vtnet_softc *sc;
451 	struct ifnet *ifp;
452 
453 	sc = device_get_softc(dev);
454 	ifp = sc->vtnet_ifp;
455 
456 	if (device_is_attached(dev)) {
457 		VTNET_CORE_LOCK(sc);
458 		vtnet_stop(sc);
459 		VTNET_CORE_UNLOCK(sc);
460 
461 		callout_drain(&sc->vtnet_tick_ch);
462 		vtnet_drain_taskqueues(sc);
463 
464 		ether_ifdetach(ifp);
465 	}
466 
467 #ifdef DEV_NETMAP
468 	netmap_detach(ifp);
469 #endif /* DEV_NETMAP */
470 
471 	vtnet_free_taskqueues(sc);
472 
473 	if (sc->vtnet_vlan_attach != NULL) {
474 		EVENTHANDLER_DEREGISTER(vlan_config, sc->vtnet_vlan_attach);
475 		sc->vtnet_vlan_attach = NULL;
476 	}
477 	if (sc->vtnet_vlan_detach != NULL) {
478 		EVENTHANDLER_DEREGISTER(vlan_unconfig, sc->vtnet_vlan_detach);
479 		sc->vtnet_vlan_detach = NULL;
480 	}
481 
482 	ifmedia_removeall(&sc->vtnet_media);
483 
484 	if (ifp != NULL) {
485 		if_free(ifp);
486 		sc->vtnet_ifp = NULL;
487 	}
488 
489 	vtnet_free_rxtx_queues(sc);
490 	vtnet_free_rx_filters(sc);
491 
492 	if (sc->vtnet_ctrl_vq != NULL)
493 		vtnet_free_ctrl_vq(sc);
494 
495 	VTNET_CORE_LOCK_DESTROY(sc);
496 
497 	return (0);
498 }
499 
500 static int
501 vtnet_suspend(device_t dev)
502 {
503 	struct vtnet_softc *sc;
504 
505 	sc = device_get_softc(dev);
506 
507 	VTNET_CORE_LOCK(sc);
508 	vtnet_stop(sc);
509 	sc->vtnet_flags |= VTNET_FLAG_SUSPENDED;
510 	VTNET_CORE_UNLOCK(sc);
511 
512 	return (0);
513 }
514 
515 static int
516 vtnet_resume(device_t dev)
517 {
518 	struct vtnet_softc *sc;
519 	struct ifnet *ifp;
520 
521 	sc = device_get_softc(dev);
522 	ifp = sc->vtnet_ifp;
523 
524 	VTNET_CORE_LOCK(sc);
525 	if (ifp->if_flags & IFF_UP)
526 		vtnet_init_locked(sc);
527 	sc->vtnet_flags &= ~VTNET_FLAG_SUSPENDED;
528 	VTNET_CORE_UNLOCK(sc);
529 
530 	return (0);
531 }
532 
533 static int
534 vtnet_shutdown(device_t dev)
535 {
536 
537 	/*
538 	 * Suspend already does all of what we need to
539 	 * do here; we just never expect to be resumed.
540 	 */
541 	return (vtnet_suspend(dev));
542 }
543 
544 static int
545 vtnet_attach_completed(device_t dev)
546 {
547 
548 	vtnet_attach_disable_promisc(device_get_softc(dev));
549 
550 	return (0);
551 }
552 
553 static int
554 vtnet_config_change(device_t dev)
555 {
556 	struct vtnet_softc *sc;
557 
558 	sc = device_get_softc(dev);
559 
560 	VTNET_CORE_LOCK(sc);
561 	vtnet_update_link_status(sc);
562 	if (sc->vtnet_link_active != 0)
563 		vtnet_tx_start_all(sc);
564 	VTNET_CORE_UNLOCK(sc);
565 
566 	return (0);
567 }
568 
569 static void
570 vtnet_negotiate_features(struct vtnet_softc *sc)
571 {
572 	device_t dev;
573 	uint64_t mask, features;
574 
575 	dev = sc->vtnet_dev;
576 	mask = 0;
577 
578 	/*
579 	 * TSO and LRO are only available when their corresponding checksum
580 	 * offload feature is also negotiated.
581 	 */
582 	if (vtnet_tunable_int(sc, "csum_disable", vtnet_csum_disable)) {
583 		mask |= VIRTIO_NET_F_CSUM | VIRTIO_NET_F_GUEST_CSUM;
584 		mask |= VTNET_TSO_FEATURES | VTNET_LRO_FEATURES;
585 	}
586 	if (vtnet_tunable_int(sc, "tso_disable", vtnet_tso_disable))
587 		mask |= VTNET_TSO_FEATURES;
588 	if (vtnet_tunable_int(sc, "lro_disable", vtnet_lro_disable))
589 		mask |= VTNET_LRO_FEATURES;
590 #ifndef VTNET_LEGACY_TX
591 	if (vtnet_tunable_int(sc, "mq_disable", vtnet_mq_disable))
592 		mask |= VIRTIO_NET_F_MQ;
593 #else
594 	mask |= VIRTIO_NET_F_MQ;
595 #endif
596 
597 	features = VTNET_FEATURES & ~mask;
598 	sc->vtnet_features = virtio_negotiate_features(dev, features);
599 
600 	if (virtio_with_feature(dev, VTNET_LRO_FEATURES) &&
601 	    virtio_with_feature(dev, VIRTIO_NET_F_MRG_RXBUF) == 0) {
602 		/*
603 		 * LRO without mergeable buffers requires special care. This
604 		 * is not ideal because every receive buffer must be large
605 		 * enough to hold the maximum TCP packet, the Ethernet header,
606 		 * and the header. This requires up to 34 descriptors with
607 		 * MCLBYTES clusters. If we do not have indirect descriptors,
608 		 * LRO is disabled since the virtqueue will not contain very
609 		 * many receive buffers.
610 		 */
611 		if (!virtio_with_feature(dev, VIRTIO_RING_F_INDIRECT_DESC)) {
612 			device_printf(dev,
613 			    "LRO disabled due to both mergeable buffers and "
614 			    "indirect descriptors not negotiated\n");
615 
616 			features &= ~VTNET_LRO_FEATURES;
617 			sc->vtnet_features =
618 			    virtio_negotiate_features(dev, features);
619 		} else
620 			sc->vtnet_flags |= VTNET_FLAG_LRO_NOMRG;
621 	}
622 }
623 
624 static void
625 vtnet_setup_features(struct vtnet_softc *sc)
626 {
627 	device_t dev;
628 
629 	dev = sc->vtnet_dev;
630 
631 	vtnet_negotiate_features(sc);
632 
633 	if (virtio_with_feature(dev, VIRTIO_RING_F_INDIRECT_DESC))
634 		sc->vtnet_flags |= VTNET_FLAG_INDIRECT;
635 	if (virtio_with_feature(dev, VIRTIO_RING_F_EVENT_IDX))
636 		sc->vtnet_flags |= VTNET_FLAG_EVENT_IDX;
637 
638 	if (virtio_with_feature(dev, VIRTIO_NET_F_MAC)) {
639 		/* This feature should always be negotiated. */
640 		sc->vtnet_flags |= VTNET_FLAG_MAC;
641 	}
642 
643 	if (virtio_with_feature(dev, VIRTIO_NET_F_MRG_RXBUF)) {
644 		sc->vtnet_flags |= VTNET_FLAG_MRG_RXBUFS;
645 		sc->vtnet_hdr_size = sizeof(struct virtio_net_hdr_mrg_rxbuf);
646 	} else
647 		sc->vtnet_hdr_size = sizeof(struct virtio_net_hdr);
648 
649 	if (sc->vtnet_flags & VTNET_FLAG_MRG_RXBUFS)
650 		sc->vtnet_rx_nsegs = VTNET_MRG_RX_SEGS;
651 	else if (sc->vtnet_flags & VTNET_FLAG_LRO_NOMRG)
652 		sc->vtnet_rx_nsegs = VTNET_MAX_RX_SEGS;
653 	else
654 		sc->vtnet_rx_nsegs = VTNET_MIN_RX_SEGS;
655 
656 	if (virtio_with_feature(dev, VIRTIO_NET_F_GSO) ||
657 	    virtio_with_feature(dev, VIRTIO_NET_F_HOST_TSO4) ||
658 	    virtio_with_feature(dev, VIRTIO_NET_F_HOST_TSO6))
659 		sc->vtnet_tx_nsegs = VTNET_MAX_TX_SEGS;
660 	else
661 		sc->vtnet_tx_nsegs = VTNET_MIN_TX_SEGS;
662 
663 	if (virtio_with_feature(dev, VIRTIO_NET_F_CTRL_VQ)) {
664 		sc->vtnet_flags |= VTNET_FLAG_CTRL_VQ;
665 
666 		if (virtio_with_feature(dev, VIRTIO_NET_F_CTRL_RX))
667 			sc->vtnet_flags |= VTNET_FLAG_CTRL_RX;
668 		if (virtio_with_feature(dev, VIRTIO_NET_F_CTRL_VLAN))
669 			sc->vtnet_flags |= VTNET_FLAG_VLAN_FILTER;
670 		if (virtio_with_feature(dev, VIRTIO_NET_F_CTRL_MAC_ADDR))
671 			sc->vtnet_flags |= VTNET_FLAG_CTRL_MAC;
672 	}
673 
674 	if (virtio_with_feature(dev, VIRTIO_NET_F_MQ) &&
675 	    sc->vtnet_flags & VTNET_FLAG_CTRL_VQ) {
676 		sc->vtnet_max_vq_pairs = virtio_read_dev_config_2(dev,
677 		    offsetof(struct virtio_net_config, max_virtqueue_pairs));
678 	} else
679 		sc->vtnet_max_vq_pairs = 1;
680 
681 	if (sc->vtnet_max_vq_pairs > 1) {
682 		/*
683 		 * Limit the maximum number of queue pairs to the lower of
684 		 * the number of CPUs and the configured maximum.
685 		 * The actual number of queues that get used may be less.
686 		 */
687 		int max;
688 
689 		max = vtnet_tunable_int(sc, "mq_max_pairs", vtnet_mq_max_pairs);
690 		if (max > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN) {
691 			if (max > mp_ncpus)
692 				max = mp_ncpus;
693 			if (max > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX)
694 				max = VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX;
695 			if (max > 1) {
696 				sc->vtnet_requested_vq_pairs = max;
697 				sc->vtnet_flags |= VTNET_FLAG_MULTIQ;
698 			}
699 		}
700 	}
701 }
702 
703 static int
704 vtnet_init_rxq(struct vtnet_softc *sc, int id)
705 {
706 	struct vtnet_rxq *rxq;
707 
708 	rxq = &sc->vtnet_rxqs[id];
709 
710 	snprintf(rxq->vtnrx_name, sizeof(rxq->vtnrx_name), "%s-rx%d",
711 	    device_get_nameunit(sc->vtnet_dev), id);
712 	mtx_init(&rxq->vtnrx_mtx, rxq->vtnrx_name, NULL, MTX_DEF);
713 
714 	rxq->vtnrx_sc = sc;
715 	rxq->vtnrx_id = id;
716 
717 	rxq->vtnrx_sg = sglist_alloc(sc->vtnet_rx_nsegs, M_NOWAIT);
718 	if (rxq->vtnrx_sg == NULL)
719 		return (ENOMEM);
720 
721 	NET_TASK_INIT(&rxq->vtnrx_intrtask, 0, vtnet_rxq_tq_intr, rxq);
722 	rxq->vtnrx_tq = taskqueue_create(rxq->vtnrx_name, M_NOWAIT,
723 	    taskqueue_thread_enqueue, &rxq->vtnrx_tq);
724 
725 	return (rxq->vtnrx_tq == NULL ? ENOMEM : 0);
726 }
727 
728 static int
729 vtnet_init_txq(struct vtnet_softc *sc, int id)
730 {
731 	struct vtnet_txq *txq;
732 
733 	txq = &sc->vtnet_txqs[id];
734 
735 	snprintf(txq->vtntx_name, sizeof(txq->vtntx_name), "%s-tx%d",
736 	    device_get_nameunit(sc->vtnet_dev), id);
737 	mtx_init(&txq->vtntx_mtx, txq->vtntx_name, NULL, MTX_DEF);
738 
739 	txq->vtntx_sc = sc;
740 	txq->vtntx_id = id;
741 
742 	txq->vtntx_sg = sglist_alloc(sc->vtnet_tx_nsegs, M_NOWAIT);
743 	if (txq->vtntx_sg == NULL)
744 		return (ENOMEM);
745 
746 #ifndef VTNET_LEGACY_TX
747 	txq->vtntx_br = buf_ring_alloc(VTNET_DEFAULT_BUFRING_SIZE, M_DEVBUF,
748 	    M_NOWAIT, &txq->vtntx_mtx);
749 	if (txq->vtntx_br == NULL)
750 		return (ENOMEM);
751 
752 	TASK_INIT(&txq->vtntx_defrtask, 0, vtnet_txq_tq_deferred, txq);
753 #endif
754 	TASK_INIT(&txq->vtntx_intrtask, 0, vtnet_txq_tq_intr, txq);
755 	txq->vtntx_tq = taskqueue_create(txq->vtntx_name, M_NOWAIT,
756 	    taskqueue_thread_enqueue, &txq->vtntx_tq);
757 	if (txq->vtntx_tq == NULL)
758 		return (ENOMEM);
759 
760 	return (0);
761 }
762 
763 static int
764 vtnet_alloc_rxtx_queues(struct vtnet_softc *sc)
765 {
766 	int i, npairs, error;
767 
768 	npairs = sc->vtnet_max_vq_pairs;
769 
770 	sc->vtnet_rxqs = malloc(sizeof(struct vtnet_rxq) * npairs, M_DEVBUF,
771 	    M_NOWAIT | M_ZERO);
772 	sc->vtnet_txqs = malloc(sizeof(struct vtnet_txq) * npairs, M_DEVBUF,
773 	    M_NOWAIT | M_ZERO);
774 	if (sc->vtnet_rxqs == NULL || sc->vtnet_txqs == NULL)
775 		return (ENOMEM);
776 
777 	for (i = 0; i < npairs; i++) {
778 		error = vtnet_init_rxq(sc, i);
779 		if (error)
780 			return (error);
781 		error = vtnet_init_txq(sc, i);
782 		if (error)
783 			return (error);
784 	}
785 
786 	vtnet_setup_queue_sysctl(sc);
787 
788 	return (0);
789 }
790 
791 static void
792 vtnet_destroy_rxq(struct vtnet_rxq *rxq)
793 {
794 
795 	rxq->vtnrx_sc = NULL;
796 	rxq->vtnrx_id = -1;
797 
798 	if (rxq->vtnrx_sg != NULL) {
799 		sglist_free(rxq->vtnrx_sg);
800 		rxq->vtnrx_sg = NULL;
801 	}
802 
803 	if (mtx_initialized(&rxq->vtnrx_mtx) != 0)
804 		mtx_destroy(&rxq->vtnrx_mtx);
805 }
806 
807 static void
808 vtnet_destroy_txq(struct vtnet_txq *txq)
809 {
810 
811 	txq->vtntx_sc = NULL;
812 	txq->vtntx_id = -1;
813 
814 	if (txq->vtntx_sg != NULL) {
815 		sglist_free(txq->vtntx_sg);
816 		txq->vtntx_sg = NULL;
817 	}
818 
819 #ifndef VTNET_LEGACY_TX
820 	if (txq->vtntx_br != NULL) {
821 		buf_ring_free(txq->vtntx_br, M_DEVBUF);
822 		txq->vtntx_br = NULL;
823 	}
824 #endif
825 
826 	if (mtx_initialized(&txq->vtntx_mtx) != 0)
827 		mtx_destroy(&txq->vtntx_mtx);
828 }
829 
830 static void
831 vtnet_free_rxtx_queues(struct vtnet_softc *sc)
832 {
833 	int i;
834 
835 	if (sc->vtnet_rxqs != NULL) {
836 		for (i = 0; i < sc->vtnet_max_vq_pairs; i++)
837 			vtnet_destroy_rxq(&sc->vtnet_rxqs[i]);
838 		free(sc->vtnet_rxqs, M_DEVBUF);
839 		sc->vtnet_rxqs = NULL;
840 	}
841 
842 	if (sc->vtnet_txqs != NULL) {
843 		for (i = 0; i < sc->vtnet_max_vq_pairs; i++)
844 			vtnet_destroy_txq(&sc->vtnet_txqs[i]);
845 		free(sc->vtnet_txqs, M_DEVBUF);
846 		sc->vtnet_txqs = NULL;
847 	}
848 }
849 
850 static int
851 vtnet_alloc_rx_filters(struct vtnet_softc *sc)
852 {
853 
854 	if (sc->vtnet_flags & VTNET_FLAG_CTRL_RX) {
855 		sc->vtnet_mac_filter = malloc(sizeof(struct vtnet_mac_filter),
856 		    M_DEVBUF, M_NOWAIT | M_ZERO);
857 		if (sc->vtnet_mac_filter == NULL)
858 			return (ENOMEM);
859 	}
860 
861 	if (sc->vtnet_flags & VTNET_FLAG_VLAN_FILTER) {
862 		sc->vtnet_vlan_filter = malloc(sizeof(uint32_t) *
863 		    VTNET_VLAN_FILTER_NWORDS, M_DEVBUF, M_NOWAIT | M_ZERO);
864 		if (sc->vtnet_vlan_filter == NULL)
865 			return (ENOMEM);
866 	}
867 
868 	return (0);
869 }
870 
871 static void
872 vtnet_free_rx_filters(struct vtnet_softc *sc)
873 {
874 
875 	if (sc->vtnet_mac_filter != NULL) {
876 		free(sc->vtnet_mac_filter, M_DEVBUF);
877 		sc->vtnet_mac_filter = NULL;
878 	}
879 
880 	if (sc->vtnet_vlan_filter != NULL) {
881 		free(sc->vtnet_vlan_filter, M_DEVBUF);
882 		sc->vtnet_vlan_filter = NULL;
883 	}
884 }
885 
886 static int
887 vtnet_alloc_virtqueues(struct vtnet_softc *sc)
888 {
889 	device_t dev;
890 	struct vq_alloc_info *info;
891 	struct vtnet_rxq *rxq;
892 	struct vtnet_txq *txq;
893 	int i, idx, flags, nvqs, error;
894 
895 	dev = sc->vtnet_dev;
896 	flags = 0;
897 
898 	nvqs = sc->vtnet_max_vq_pairs * 2;
899 	if (sc->vtnet_flags & VTNET_FLAG_CTRL_VQ)
900 		nvqs++;
901 
902 	info = malloc(sizeof(struct vq_alloc_info) * nvqs, M_TEMP, M_NOWAIT);
903 	if (info == NULL)
904 		return (ENOMEM);
905 
906 	for (i = 0, idx = 0; i < sc->vtnet_max_vq_pairs; i++, idx+=2) {
907 		rxq = &sc->vtnet_rxqs[i];
908 		VQ_ALLOC_INFO_INIT(&info[idx], sc->vtnet_rx_nsegs,
909 		    vtnet_rx_vq_intr, rxq, &rxq->vtnrx_vq,
910 		    "%s-%d rx", device_get_nameunit(dev), rxq->vtnrx_id);
911 
912 		txq = &sc->vtnet_txqs[i];
913 		VQ_ALLOC_INFO_INIT(&info[idx+1], sc->vtnet_tx_nsegs,
914 		    vtnet_tx_vq_intr, txq, &txq->vtntx_vq,
915 		    "%s-%d tx", device_get_nameunit(dev), txq->vtntx_id);
916 	}
917 
918 	if (sc->vtnet_flags & VTNET_FLAG_CTRL_VQ) {
919 		VQ_ALLOC_INFO_INIT(&info[idx], 0, NULL, NULL,
920 		    &sc->vtnet_ctrl_vq, "%s ctrl", device_get_nameunit(dev));
921 	}
922 
923 	/*
924 	 * Enable interrupt binding if this is multiqueue. This only matters
925 	 * when per-vq MSIX is available.
926 	 */
927 	if (sc->vtnet_flags & VTNET_FLAG_MULTIQ)
928 		flags |= 0;
929 
930 	error = virtio_alloc_virtqueues(dev, flags, nvqs, info);
931 	free(info, M_TEMP);
932 
933 	return (error);
934 }
935 
936 static int
937 vtnet_setup_interface(struct vtnet_softc *sc)
938 {
939 	device_t dev;
940 	struct pfil_head_args pa;
941 	struct ifnet *ifp;
942 
943 	dev = sc->vtnet_dev;
944 
945 	ifp = sc->vtnet_ifp = if_alloc(IFT_ETHER);
946 	if (ifp == NULL) {
947 		device_printf(dev, "cannot allocate ifnet structure\n");
948 		return (ENOSPC);
949 	}
950 
951 	if_initname(ifp, device_get_name(dev), device_get_unit(dev));
952 	ifp->if_baudrate = IF_Gbps(10);	/* Approx. */
953 	ifp->if_softc = sc;
954 	ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST |
955 	    IFF_KNOWSEPOCH;
956 	ifp->if_init = vtnet_init;
957 	ifp->if_ioctl = vtnet_ioctl;
958 	ifp->if_get_counter = vtnet_get_counter;
959 #ifndef VTNET_LEGACY_TX
960 	ifp->if_transmit = vtnet_txq_mq_start;
961 	ifp->if_qflush = vtnet_qflush;
962 #else
963 	struct virtqueue *vq = sc->vtnet_txqs[0].vtntx_vq;
964 	ifp->if_start = vtnet_start;
965 	IFQ_SET_MAXLEN(&ifp->if_snd, virtqueue_size(vq) - 1);
966 	ifp->if_snd.ifq_drv_maxlen = virtqueue_size(vq) - 1;
967 	IFQ_SET_READY(&ifp->if_snd);
968 #endif
969 
970 	ifmedia_init(&sc->vtnet_media, IFM_IMASK, vtnet_ifmedia_upd,
971 	    vtnet_ifmedia_sts);
972 	ifmedia_add(&sc->vtnet_media, VTNET_MEDIATYPE, 0, NULL);
973 	ifmedia_set(&sc->vtnet_media, VTNET_MEDIATYPE);
974 
975 	/* Read (or generate) the MAC address for the adapter. */
976 	vtnet_get_hwaddr(sc);
977 
978 	ether_ifattach(ifp, sc->vtnet_hwaddr);
979 
980 	if (virtio_with_feature(dev, VIRTIO_NET_F_STATUS))
981 		ifp->if_capabilities |= IFCAP_LINKSTATE;
982 
983 	/* Tell the upper layer(s) we support long frames. */
984 	ifp->if_hdrlen = sizeof(struct ether_vlan_header);
985 	ifp->if_capabilities |= IFCAP_JUMBO_MTU | IFCAP_VLAN_MTU;
986 
987 	if (virtio_with_feature(dev, VIRTIO_NET_F_CSUM)) {
988 		ifp->if_capabilities |= IFCAP_TXCSUM | IFCAP_TXCSUM_IPV6;
989 
990 		if (virtio_with_feature(dev, VIRTIO_NET_F_GSO)) {
991 			ifp->if_capabilities |= IFCAP_TSO4 | IFCAP_TSO6;
992 			sc->vtnet_flags |= VTNET_FLAG_TSO_ECN;
993 		} else {
994 			if (virtio_with_feature(dev, VIRTIO_NET_F_HOST_TSO4))
995 				ifp->if_capabilities |= IFCAP_TSO4;
996 			if (virtio_with_feature(dev, VIRTIO_NET_F_HOST_TSO6))
997 				ifp->if_capabilities |= IFCAP_TSO6;
998 			if (virtio_with_feature(dev, VIRTIO_NET_F_HOST_ECN))
999 				sc->vtnet_flags |= VTNET_FLAG_TSO_ECN;
1000 		}
1001 
1002 		if (ifp->if_capabilities & IFCAP_TSO)
1003 			ifp->if_capabilities |= IFCAP_VLAN_HWTSO;
1004 	}
1005 
1006 	if (virtio_with_feature(dev, VIRTIO_NET_F_GUEST_CSUM)) {
1007 		ifp->if_capabilities |= IFCAP_RXCSUM | IFCAP_RXCSUM_IPV6;
1008 
1009 		if (virtio_with_feature(dev, VIRTIO_NET_F_GUEST_TSO4) ||
1010 		    virtio_with_feature(dev, VIRTIO_NET_F_GUEST_TSO6))
1011 			ifp->if_capabilities |= IFCAP_LRO;
1012 	}
1013 
1014 	if (ifp->if_capabilities & IFCAP_HWCSUM) {
1015 		/*
1016 		 * VirtIO does not support VLAN tagging, but we can fake
1017 		 * it by inserting and removing the 802.1Q header during
1018 		 * transmit and receive. We are then able to do checksum
1019 		 * offloading of VLAN frames.
1020 		 */
1021 		ifp->if_capabilities |=
1022 		    IFCAP_VLAN_HWTAGGING | IFCAP_VLAN_HWCSUM;
1023 	}
1024 
1025 	ifp->if_capenable = ifp->if_capabilities;
1026 
1027 	/*
1028 	 * Capabilities after here are not enabled by default.
1029 	 */
1030 
1031 	if (sc->vtnet_flags & VTNET_FLAG_VLAN_FILTER) {
1032 		ifp->if_capabilities |= IFCAP_VLAN_HWFILTER;
1033 
1034 		sc->vtnet_vlan_attach = EVENTHANDLER_REGISTER(vlan_config,
1035 		    vtnet_register_vlan, sc, EVENTHANDLER_PRI_FIRST);
1036 		sc->vtnet_vlan_detach = EVENTHANDLER_REGISTER(vlan_unconfig,
1037 		    vtnet_unregister_vlan, sc, EVENTHANDLER_PRI_FIRST);
1038 	}
1039 
1040 	vtnet_set_rx_process_limit(sc);
1041 	vtnet_set_tx_intr_threshold(sc);
1042 
1043 	DEBUGNET_SET(ifp, vtnet);
1044 
1045 	pa.pa_version = PFIL_VERSION;
1046 	pa.pa_flags = PFIL_IN;
1047 	pa.pa_type = PFIL_TYPE_ETHERNET;
1048 	pa.pa_headname = ifp->if_xname;
1049 	sc->vtnet_pfil = pfil_head_register(&pa);
1050 
1051 	return (0);
1052 }
1053 
1054 static int
1055 vtnet_change_mtu(struct vtnet_softc *sc, int new_mtu)
1056 {
1057 	struct ifnet *ifp;
1058 	int frame_size, clsize;
1059 
1060 	ifp = sc->vtnet_ifp;
1061 
1062 	if (new_mtu < ETHERMIN || new_mtu > VTNET_MAX_MTU)
1063 		return (EINVAL);
1064 
1065 	frame_size = sc->vtnet_hdr_size + sizeof(struct ether_vlan_header) +
1066 	    new_mtu;
1067 
1068 	/*
1069 	 * Based on the new MTU (and hence frame size) determine which
1070 	 * cluster size is most appropriate for the receive queues.
1071 	 */
1072 	if (frame_size <= MCLBYTES) {
1073 		clsize = MCLBYTES;
1074 	} else if ((sc->vtnet_flags & VTNET_FLAG_MRG_RXBUFS) == 0) {
1075 		/* Avoid going past 9K jumbos. */
1076 		if (frame_size > MJUM9BYTES)
1077 			return (EINVAL);
1078 		clsize = MJUM9BYTES;
1079 	} else
1080 		clsize = MJUMPAGESIZE;
1081 
1082 	ifp->if_mtu = new_mtu;
1083 	sc->vtnet_rx_new_clsize = clsize;
1084 
1085 	if (ifp->if_drv_flags & IFF_DRV_RUNNING) {
1086 		ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
1087 		vtnet_init_locked(sc);
1088 	}
1089 
1090 	return (0);
1091 }
1092 
1093 static int
1094 vtnet_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
1095 {
1096 	struct vtnet_softc *sc;
1097 	struct ifreq *ifr;
1098 	int reinit, mask, error;
1099 
1100 	sc = ifp->if_softc;
1101 	ifr = (struct ifreq *) data;
1102 	error = 0;
1103 
1104 	switch (cmd) {
1105 	case SIOCSIFMTU:
1106 		if (ifp->if_mtu != ifr->ifr_mtu) {
1107 			VTNET_CORE_LOCK(sc);
1108 			error = vtnet_change_mtu(sc, ifr->ifr_mtu);
1109 			VTNET_CORE_UNLOCK(sc);
1110 		}
1111 		break;
1112 
1113 	case SIOCSIFFLAGS:
1114 		VTNET_CORE_LOCK(sc);
1115 		if ((ifp->if_flags & IFF_UP) == 0) {
1116 			if (ifp->if_drv_flags & IFF_DRV_RUNNING)
1117 				vtnet_stop(sc);
1118 		} else if (ifp->if_drv_flags & IFF_DRV_RUNNING) {
1119 			if ((ifp->if_flags ^ sc->vtnet_if_flags) &
1120 			    (IFF_PROMISC | IFF_ALLMULTI)) {
1121 				if (sc->vtnet_flags & VTNET_FLAG_CTRL_RX)
1122 					vtnet_rx_filter(sc);
1123 				else {
1124 					ifp->if_flags |= IFF_PROMISC;
1125 					if ((ifp->if_flags ^ sc->vtnet_if_flags)
1126 					    & IFF_ALLMULTI)
1127 						error = ENOTSUP;
1128 				}
1129 			}
1130 		} else
1131 			vtnet_init_locked(sc);
1132 
1133 		if (error == 0)
1134 			sc->vtnet_if_flags = ifp->if_flags;
1135 		VTNET_CORE_UNLOCK(sc);
1136 		break;
1137 
1138 	case SIOCADDMULTI:
1139 	case SIOCDELMULTI:
1140 		if ((sc->vtnet_flags & VTNET_FLAG_CTRL_RX) == 0)
1141 			break;
1142 		VTNET_CORE_LOCK(sc);
1143 		if (ifp->if_drv_flags & IFF_DRV_RUNNING)
1144 			vtnet_rx_filter_mac(sc);
1145 		VTNET_CORE_UNLOCK(sc);
1146 		break;
1147 
1148 	case SIOCSIFMEDIA:
1149 	case SIOCGIFMEDIA:
1150 		error = ifmedia_ioctl(ifp, ifr, &sc->vtnet_media, cmd);
1151 		break;
1152 
1153 	case SIOCSIFCAP:
1154 		VTNET_CORE_LOCK(sc);
1155 		mask = ifr->ifr_reqcap ^ ifp->if_capenable;
1156 
1157 		if (mask & IFCAP_TXCSUM)
1158 			ifp->if_capenable ^= IFCAP_TXCSUM;
1159 		if (mask & IFCAP_TXCSUM_IPV6)
1160 			ifp->if_capenable ^= IFCAP_TXCSUM_IPV6;
1161 		if (mask & IFCAP_TSO4)
1162 			ifp->if_capenable ^= IFCAP_TSO4;
1163 		if (mask & IFCAP_TSO6)
1164 			ifp->if_capenable ^= IFCAP_TSO6;
1165 
1166 		if (mask & (IFCAP_RXCSUM | IFCAP_RXCSUM_IPV6 | IFCAP_LRO |
1167 		    IFCAP_VLAN_HWFILTER)) {
1168 			/* These Rx features require us to renegotiate. */
1169 			reinit = 1;
1170 
1171 			if (mask & IFCAP_RXCSUM)
1172 				ifp->if_capenable ^= IFCAP_RXCSUM;
1173 			if (mask & IFCAP_RXCSUM_IPV6)
1174 				ifp->if_capenable ^= IFCAP_RXCSUM_IPV6;
1175 			if (mask & IFCAP_LRO)
1176 				ifp->if_capenable ^= IFCAP_LRO;
1177 			if (mask & IFCAP_VLAN_HWFILTER)
1178 				ifp->if_capenable ^= IFCAP_VLAN_HWFILTER;
1179 		} else
1180 			reinit = 0;
1181 
1182 		if (mask & IFCAP_VLAN_HWTSO)
1183 			ifp->if_capenable ^= IFCAP_VLAN_HWTSO;
1184 		if (mask & IFCAP_VLAN_HWTAGGING)
1185 			ifp->if_capenable ^= IFCAP_VLAN_HWTAGGING;
1186 
1187 		if (reinit && (ifp->if_drv_flags & IFF_DRV_RUNNING)) {
1188 			ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
1189 			vtnet_init_locked(sc);
1190 		}
1191 
1192 		VTNET_CORE_UNLOCK(sc);
1193 		VLAN_CAPABILITIES(ifp);
1194 
1195 		break;
1196 
1197 	default:
1198 		error = ether_ioctl(ifp, cmd, data);
1199 		break;
1200 	}
1201 
1202 	VTNET_CORE_LOCK_ASSERT_NOTOWNED(sc);
1203 
1204 	return (error);
1205 }
1206 
1207 static int
1208 vtnet_rxq_populate(struct vtnet_rxq *rxq)
1209 {
1210 	struct virtqueue *vq;
1211 	int nbufs, error;
1212 
1213 #ifdef DEV_NETMAP
1214 	error = vtnet_netmap_rxq_populate(rxq);
1215 	if (error >= 0)
1216 		return (error);
1217 #endif  /* DEV_NETMAP */
1218 
1219 	vq = rxq->vtnrx_vq;
1220 	error = ENOSPC;
1221 
1222 	for (nbufs = 0; !virtqueue_full(vq); nbufs++) {
1223 		error = vtnet_rxq_new_buf(rxq);
1224 		if (error)
1225 			break;
1226 	}
1227 
1228 	if (nbufs > 0) {
1229 		virtqueue_notify(vq);
1230 		/*
1231 		 * EMSGSIZE signifies the virtqueue did not have enough
1232 		 * entries available to hold the last mbuf. This is not
1233 		 * an error.
1234 		 */
1235 		if (error == EMSGSIZE)
1236 			error = 0;
1237 	}
1238 
1239 	return (error);
1240 }
1241 
1242 static void
1243 vtnet_rxq_free_mbufs(struct vtnet_rxq *rxq)
1244 {
1245 	struct virtqueue *vq;
1246 	struct mbuf *m;
1247 	int last;
1248 #ifdef DEV_NETMAP
1249 	int netmap_bufs = vtnet_netmap_queue_on(rxq->vtnrx_sc, NR_RX,
1250 						rxq->vtnrx_id);
1251 #else  /* !DEV_NETMAP */
1252 	int netmap_bufs = 0;
1253 #endif /* !DEV_NETMAP */
1254 
1255 	vq = rxq->vtnrx_vq;
1256 	last = 0;
1257 
1258 	while ((m = virtqueue_drain(vq, &last)) != NULL) {
1259 		if (!netmap_bufs)
1260 			m_freem(m);
1261 	}
1262 
1263 	KASSERT(virtqueue_empty(vq),
1264 	    ("%s: mbufs remaining in rx queue %p", __func__, rxq));
1265 }
1266 
1267 static struct mbuf *
1268 vtnet_rx_alloc_buf(struct vtnet_softc *sc, int nbufs, struct mbuf **m_tailp)
1269 {
1270 	struct mbuf *m_head, *m_tail, *m;
1271 	int i, clsize;
1272 
1273 	clsize = sc->vtnet_rx_clsize;
1274 
1275 	KASSERT(nbufs == 1 || sc->vtnet_flags & VTNET_FLAG_LRO_NOMRG,
1276 	    ("%s: chained mbuf %d request without LRO_NOMRG", __func__, nbufs));
1277 
1278 	m_head = m_getjcl(M_NOWAIT, MT_DATA, M_PKTHDR, clsize);
1279 	if (m_head == NULL)
1280 		goto fail;
1281 
1282 	m_head->m_len = clsize;
1283 	m_tail = m_head;
1284 
1285 	/* Allocate the rest of the chain. */
1286 	for (i = 1; i < nbufs; i++) {
1287 		m = m_getjcl(M_NOWAIT, MT_DATA, 0, clsize);
1288 		if (m == NULL)
1289 			goto fail;
1290 
1291 		m->m_len = clsize;
1292 		m_tail->m_next = m;
1293 		m_tail = m;
1294 	}
1295 
1296 	if (m_tailp != NULL)
1297 		*m_tailp = m_tail;
1298 
1299 	return (m_head);
1300 
1301 fail:
1302 	sc->vtnet_stats.mbuf_alloc_failed++;
1303 	m_freem(m_head);
1304 
1305 	return (NULL);
1306 }
1307 
1308 /*
1309  * Slow path for when LRO without mergeable buffers is negotiated.
1310  */
1311 static int
1312 vtnet_rxq_replace_lro_nomgr_buf(struct vtnet_rxq *rxq, struct mbuf *m0,
1313     int len0)
1314 {
1315 	struct vtnet_softc *sc;
1316 	struct mbuf *m, *m_prev;
1317 	struct mbuf *m_new, *m_tail;
1318 	int len, clsize, nreplace, error;
1319 
1320 	sc = rxq->vtnrx_sc;
1321 	clsize = sc->vtnet_rx_clsize;
1322 
1323 	m_prev = NULL;
1324 	m_tail = NULL;
1325 	nreplace = 0;
1326 
1327 	m = m0;
1328 	len = len0;
1329 
1330 	/*
1331 	 * Since these mbuf chains are so large, we avoid allocating an
1332 	 * entire replacement chain if possible. When the received frame
1333 	 * did not consume the entire chain, the unused mbufs are moved
1334 	 * to the replacement chain.
1335 	 */
1336 	while (len > 0) {
1337 		/*
1338 		 * Something is seriously wrong if we received a frame
1339 		 * larger than the chain. Drop it.
1340 		 */
1341 		if (m == NULL) {
1342 			sc->vtnet_stats.rx_frame_too_large++;
1343 			return (EMSGSIZE);
1344 		}
1345 
1346 		/* We always allocate the same cluster size. */
1347 		KASSERT(m->m_len == clsize,
1348 		    ("%s: mbuf size %d is not the cluster size %d",
1349 		    __func__, m->m_len, clsize));
1350 
1351 		m->m_len = MIN(m->m_len, len);
1352 		len -= m->m_len;
1353 
1354 		m_prev = m;
1355 		m = m->m_next;
1356 		nreplace++;
1357 	}
1358 
1359 	KASSERT(nreplace <= sc->vtnet_rx_nmbufs,
1360 	    ("%s: too many replacement mbufs %d max %d", __func__, nreplace,
1361 	    sc->vtnet_rx_nmbufs));
1362 
1363 	m_new = vtnet_rx_alloc_buf(sc, nreplace, &m_tail);
1364 	if (m_new == NULL) {
1365 		m_prev->m_len = clsize;
1366 		return (ENOBUFS);
1367 	}
1368 
1369 	/*
1370 	 * Move any unused mbufs from the received chain onto the end
1371 	 * of the new chain.
1372 	 */
1373 	if (m_prev->m_next != NULL) {
1374 		m_tail->m_next = m_prev->m_next;
1375 		m_prev->m_next = NULL;
1376 	}
1377 
1378 	error = vtnet_rxq_enqueue_buf(rxq, m_new);
1379 	if (error) {
1380 		/*
1381 		 * BAD! We could not enqueue the replacement mbuf chain. We
1382 		 * must restore the m0 chain to the original state if it was
1383 		 * modified so we can subsequently discard it.
1384 		 *
1385 		 * NOTE: The replacement is suppose to be an identical copy
1386 		 * to the one just dequeued so this is an unexpected error.
1387 		 */
1388 		sc->vtnet_stats.rx_enq_replacement_failed++;
1389 
1390 		if (m_tail->m_next != NULL) {
1391 			m_prev->m_next = m_tail->m_next;
1392 			m_tail->m_next = NULL;
1393 		}
1394 
1395 		m_prev->m_len = clsize;
1396 		m_freem(m_new);
1397 	}
1398 
1399 	return (error);
1400 }
1401 
1402 static int
1403 vtnet_rxq_replace_buf(struct vtnet_rxq *rxq, struct mbuf *m, int len)
1404 {
1405 	struct vtnet_softc *sc;
1406 	struct mbuf *m_new;
1407 	int error;
1408 
1409 	sc = rxq->vtnrx_sc;
1410 
1411 	KASSERT(sc->vtnet_flags & VTNET_FLAG_LRO_NOMRG || m->m_next == NULL,
1412 	    ("%s: chained mbuf without LRO_NOMRG", __func__));
1413 
1414 	if (m->m_next == NULL) {
1415 		/* Fast-path for the common case of just one mbuf. */
1416 		if (m->m_len < len)
1417 			return (EINVAL);
1418 
1419 		m_new = vtnet_rx_alloc_buf(sc, 1, NULL);
1420 		if (m_new == NULL)
1421 			return (ENOBUFS);
1422 
1423 		error = vtnet_rxq_enqueue_buf(rxq, m_new);
1424 		if (error) {
1425 			/*
1426 			 * The new mbuf is suppose to be an identical
1427 			 * copy of the one just dequeued so this is an
1428 			 * unexpected error.
1429 			 */
1430 			m_freem(m_new);
1431 			sc->vtnet_stats.rx_enq_replacement_failed++;
1432 		} else
1433 			m->m_len = len;
1434 	} else
1435 		error = vtnet_rxq_replace_lro_nomgr_buf(rxq, m, len);
1436 
1437 	return (error);
1438 }
1439 
1440 static int
1441 vtnet_rxq_enqueue_buf(struct vtnet_rxq *rxq, struct mbuf *m)
1442 {
1443 	struct vtnet_softc *sc;
1444 	struct sglist *sg;
1445 	struct vtnet_rx_header *rxhdr;
1446 	uint8_t *mdata;
1447 	int offset, error;
1448 
1449 	sc = rxq->vtnrx_sc;
1450 	sg = rxq->vtnrx_sg;
1451 	mdata = mtod(m, uint8_t *);
1452 
1453 	VTNET_RXQ_LOCK_ASSERT(rxq);
1454 	KASSERT(sc->vtnet_flags & VTNET_FLAG_LRO_NOMRG || m->m_next == NULL,
1455 	    ("%s: chained mbuf without LRO_NOMRG", __func__));
1456 	KASSERT(m->m_len == sc->vtnet_rx_clsize,
1457 	    ("%s: unexpected cluster size %d/%d", __func__, m->m_len,
1458 	     sc->vtnet_rx_clsize));
1459 
1460 	sglist_reset(sg);
1461 	if ((sc->vtnet_flags & VTNET_FLAG_MRG_RXBUFS) == 0) {
1462 		MPASS(sc->vtnet_hdr_size == sizeof(struct virtio_net_hdr));
1463 		rxhdr = (struct vtnet_rx_header *) mdata;
1464 		sglist_append(sg, &rxhdr->vrh_hdr, sc->vtnet_hdr_size);
1465 		offset = sizeof(struct vtnet_rx_header);
1466 	} else
1467 		offset = 0;
1468 
1469 	sglist_append(sg, mdata + offset, m->m_len - offset);
1470 	if (m->m_next != NULL) {
1471 		error = sglist_append_mbuf(sg, m->m_next);
1472 		MPASS(error == 0);
1473 	}
1474 
1475 	error = virtqueue_enqueue(rxq->vtnrx_vq, m, sg, 0, sg->sg_nseg);
1476 
1477 	return (error);
1478 }
1479 
1480 static int
1481 vtnet_rxq_new_buf(struct vtnet_rxq *rxq)
1482 {
1483 	struct vtnet_softc *sc;
1484 	struct mbuf *m;
1485 	int error;
1486 
1487 	sc = rxq->vtnrx_sc;
1488 
1489 	m = vtnet_rx_alloc_buf(sc, sc->vtnet_rx_nmbufs, NULL);
1490 	if (m == NULL)
1491 		return (ENOBUFS);
1492 
1493 	error = vtnet_rxq_enqueue_buf(rxq, m);
1494 	if (error)
1495 		m_freem(m);
1496 
1497 	return (error);
1498 }
1499 
1500 /*
1501  * Use the checksum offset in the VirtIO header to set the
1502  * correct CSUM_* flags.
1503  */
1504 static int
1505 vtnet_rxq_csum_by_offset(struct vtnet_rxq *rxq, struct mbuf *m,
1506     uint16_t eth_type, int ip_start, struct virtio_net_hdr *hdr)
1507 {
1508 	struct vtnet_softc *sc;
1509 #if defined(INET) || defined(INET6)
1510 	int offset = hdr->csum_start + hdr->csum_offset;
1511 #endif
1512 
1513 	sc = rxq->vtnrx_sc;
1514 
1515 	/* Only do a basic sanity check on the offset. */
1516 	switch (eth_type) {
1517 #if defined(INET)
1518 	case ETHERTYPE_IP:
1519 		if (__predict_false(offset < ip_start + sizeof(struct ip)))
1520 			return (1);
1521 		break;
1522 #endif
1523 #if defined(INET6)
1524 	case ETHERTYPE_IPV6:
1525 		if (__predict_false(offset < ip_start + sizeof(struct ip6_hdr)))
1526 			return (1);
1527 		break;
1528 #endif
1529 	default:
1530 		sc->vtnet_stats.rx_csum_bad_ethtype++;
1531 		return (1);
1532 	}
1533 
1534 	/*
1535 	 * Use the offset to determine the appropriate CSUM_* flags. This is
1536 	 * a bit dirty, but we can get by with it since the checksum offsets
1537 	 * happen to be different. We assume the host host does not do IPv4
1538 	 * header checksum offloading.
1539 	 */
1540 	switch (hdr->csum_offset) {
1541 	case offsetof(struct udphdr, uh_sum):
1542 	case offsetof(struct tcphdr, th_sum):
1543 		m->m_pkthdr.csum_flags |= CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
1544 		m->m_pkthdr.csum_data = 0xFFFF;
1545 		break;
1546 	default:
1547 		sc->vtnet_stats.rx_csum_bad_offset++;
1548 		return (1);
1549 	}
1550 
1551 	return (0);
1552 }
1553 
1554 static int
1555 vtnet_rxq_csum_by_parse(struct vtnet_rxq *rxq, struct mbuf *m,
1556     uint16_t eth_type, int ip_start, struct virtio_net_hdr *hdr)
1557 {
1558 	struct vtnet_softc *sc;
1559 	int offset, proto;
1560 
1561 	sc = rxq->vtnrx_sc;
1562 
1563 	switch (eth_type) {
1564 #if defined(INET)
1565 	case ETHERTYPE_IP: {
1566 		struct ip *ip;
1567 		if (__predict_false(m->m_len < ip_start + sizeof(struct ip)))
1568 			return (1);
1569 		ip = (struct ip *)(m->m_data + ip_start);
1570 		proto = ip->ip_p;
1571 		offset = ip_start + (ip->ip_hl << 2);
1572 		break;
1573 	}
1574 #endif
1575 #if defined(INET6)
1576 	case ETHERTYPE_IPV6:
1577 		if (__predict_false(m->m_len < ip_start +
1578 		    sizeof(struct ip6_hdr)))
1579 			return (1);
1580 		offset = ip6_lasthdr(m, ip_start, IPPROTO_IPV6, &proto);
1581 		if (__predict_false(offset < 0))
1582 			return (1);
1583 		break;
1584 #endif
1585 	default:
1586 		sc->vtnet_stats.rx_csum_bad_ethtype++;
1587 		return (1);
1588 	}
1589 
1590 	switch (proto) {
1591 	case IPPROTO_TCP:
1592 		if (__predict_false(m->m_len < offset + sizeof(struct tcphdr)))
1593 			return (1);
1594 		m->m_pkthdr.csum_flags |= CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
1595 		m->m_pkthdr.csum_data = 0xFFFF;
1596 		break;
1597 	case IPPROTO_UDP:
1598 		if (__predict_false(m->m_len < offset + sizeof(struct udphdr)))
1599 			return (1);
1600 		m->m_pkthdr.csum_flags |= CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
1601 		m->m_pkthdr.csum_data = 0xFFFF;
1602 		break;
1603 	default:
1604 		/*
1605 		 * For the remaining protocols, FreeBSD does not support
1606 		 * checksum offloading, so the checksum will be recomputed.
1607 		 */
1608 #if 0
1609 		if_printf(sc->vtnet_ifp, "cksum offload of unsupported "
1610 		    "protocol eth_type=%#x proto=%d csum_start=%d "
1611 		    "csum_offset=%d\n", __func__, eth_type, proto,
1612 		    hdr->csum_start, hdr->csum_offset);
1613 #endif
1614 		break;
1615 	}
1616 
1617 	return (0);
1618 }
1619 
1620 /*
1621  * Set the appropriate CSUM_* flags. Unfortunately, the information
1622  * provided is not directly useful to us. The VirtIO header gives the
1623  * offset of the checksum, which is all Linux needs, but this is not
1624  * how FreeBSD does things. We are forced to peek inside the packet
1625  * a bit.
1626  *
1627  * It would be nice if VirtIO gave us the L4 protocol or if FreeBSD
1628  * could accept the offsets and let the stack figure it out.
1629  */
1630 static int
1631 vtnet_rxq_csum(struct vtnet_rxq *rxq, struct mbuf *m,
1632     struct virtio_net_hdr *hdr)
1633 {
1634 	struct ether_header *eh;
1635 	struct ether_vlan_header *evh;
1636 	uint16_t eth_type;
1637 	int offset, error;
1638 
1639 	eh = mtod(m, struct ether_header *);
1640 	eth_type = ntohs(eh->ether_type);
1641 	if (eth_type == ETHERTYPE_VLAN) {
1642 		/* BMV: We should handle nested VLAN tags too. */
1643 		evh = mtod(m, struct ether_vlan_header *);
1644 		eth_type = ntohs(evh->evl_proto);
1645 		offset = sizeof(struct ether_vlan_header);
1646 	} else
1647 		offset = sizeof(struct ether_header);
1648 
1649 	if (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM)
1650 		error = vtnet_rxq_csum_by_offset(rxq, m, eth_type, offset, hdr);
1651 	else
1652 		error = vtnet_rxq_csum_by_parse(rxq, m, eth_type, offset, hdr);
1653 
1654 	return (error);
1655 }
1656 
1657 static void
1658 vtnet_rxq_discard_merged_bufs(struct vtnet_rxq *rxq, int nbufs)
1659 {
1660 	struct mbuf *m;
1661 
1662 	while (--nbufs > 0) {
1663 		m = virtqueue_dequeue(rxq->vtnrx_vq, NULL);
1664 		if (m == NULL)
1665 			break;
1666 		vtnet_rxq_discard_buf(rxq, m);
1667 	}
1668 }
1669 
1670 static void
1671 vtnet_rxq_discard_buf(struct vtnet_rxq *rxq, struct mbuf *m)
1672 {
1673 	int error;
1674 
1675 	/*
1676 	 * Requeue the discarded mbuf. This should always be successful
1677 	 * since it was just dequeued.
1678 	 */
1679 	error = vtnet_rxq_enqueue_buf(rxq, m);
1680 	KASSERT(error == 0,
1681 	    ("%s: cannot requeue discarded mbuf %d", __func__, error));
1682 }
1683 
1684 static int
1685 vtnet_rxq_merged_eof(struct vtnet_rxq *rxq, struct mbuf *m_head, int nbufs)
1686 {
1687 	struct vtnet_softc *sc;
1688 	struct virtqueue *vq;
1689 	struct mbuf *m, *m_tail;
1690 	int len;
1691 
1692 	sc = rxq->vtnrx_sc;
1693 	vq = rxq->vtnrx_vq;
1694 	m_tail = m_head;
1695 
1696 	while (--nbufs > 0) {
1697 		m = virtqueue_dequeue(vq, &len);
1698 		if (m == NULL) {
1699 			rxq->vtnrx_stats.vrxs_ierrors++;
1700 			goto fail;
1701 		}
1702 
1703 		if (vtnet_rxq_new_buf(rxq) != 0) {
1704 			rxq->vtnrx_stats.vrxs_iqdrops++;
1705 			vtnet_rxq_discard_buf(rxq, m);
1706 			if (nbufs > 1)
1707 				vtnet_rxq_discard_merged_bufs(rxq, nbufs);
1708 			goto fail;
1709 		}
1710 
1711 		if (m->m_len < len)
1712 			len = m->m_len;
1713 
1714 		m->m_len = len;
1715 		m->m_flags &= ~M_PKTHDR;
1716 
1717 		m_head->m_pkthdr.len += len;
1718 		m_tail->m_next = m;
1719 		m_tail = m;
1720 	}
1721 
1722 	return (0);
1723 
1724 fail:
1725 	sc->vtnet_stats.rx_mergeable_failed++;
1726 	m_freem(m_head);
1727 
1728 	return (1);
1729 }
1730 
1731 static void
1732 vtnet_rxq_input(struct vtnet_rxq *rxq, struct mbuf *m,
1733     struct virtio_net_hdr *hdr)
1734 {
1735 	struct vtnet_softc *sc;
1736 	struct ifnet *ifp;
1737 	struct ether_header *eh;
1738 
1739 	sc = rxq->vtnrx_sc;
1740 	ifp = sc->vtnet_ifp;
1741 
1742 	if (ifp->if_capenable & IFCAP_VLAN_HWTAGGING) {
1743 		eh = mtod(m, struct ether_header *);
1744 		if (eh->ether_type == htons(ETHERTYPE_VLAN)) {
1745 			vtnet_vlan_tag_remove(m);
1746 			/*
1747 			 * With the 802.1Q header removed, update the
1748 			 * checksum starting location accordingly.
1749 			 */
1750 			if (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM)
1751 				hdr->csum_start -= ETHER_VLAN_ENCAP_LEN;
1752 		}
1753 	}
1754 
1755 	m->m_pkthdr.flowid = rxq->vtnrx_id;
1756 	M_HASHTYPE_SET(m, M_HASHTYPE_OPAQUE);
1757 
1758 	/*
1759 	 * BMV: FreeBSD does not have the UNNECESSARY and PARTIAL checksum
1760 	 * distinction that Linux does. Need to reevaluate if performing
1761 	 * offloading for the NEEDS_CSUM case is really appropriate.
1762 	 */
1763 	if (hdr->flags & (VIRTIO_NET_HDR_F_NEEDS_CSUM |
1764 	    VIRTIO_NET_HDR_F_DATA_VALID)) {
1765 		if (vtnet_rxq_csum(rxq, m, hdr) == 0)
1766 			rxq->vtnrx_stats.vrxs_csum++;
1767 		else
1768 			rxq->vtnrx_stats.vrxs_csum_failed++;
1769 	}
1770 
1771 	rxq->vtnrx_stats.vrxs_ipackets++;
1772 	rxq->vtnrx_stats.vrxs_ibytes += m->m_pkthdr.len;
1773 
1774 	VTNET_RXQ_UNLOCK(rxq);
1775 	(*ifp->if_input)(ifp, m);
1776 	VTNET_RXQ_LOCK(rxq);
1777 }
1778 
1779 static int
1780 vtnet_rxq_eof(struct vtnet_rxq *rxq)
1781 {
1782 	struct virtio_net_hdr lhdr, *hdr;
1783 	struct vtnet_softc *sc;
1784 	struct ifnet *ifp;
1785 	struct virtqueue *vq;
1786 	struct mbuf *m, *mr;
1787 	struct virtio_net_hdr_mrg_rxbuf *mhdr;
1788 	int len, deq, nbufs, adjsz, count;
1789 	pfil_return_t pfil;
1790 	bool pfil_done;
1791 
1792 	sc = rxq->vtnrx_sc;
1793 	vq = rxq->vtnrx_vq;
1794 	ifp = sc->vtnet_ifp;
1795 	hdr = &lhdr;
1796 	deq = 0;
1797 	count = sc->vtnet_rx_process_limit;
1798 
1799 	VTNET_RXQ_LOCK_ASSERT(rxq);
1800 
1801 	while (count-- > 0) {
1802 		m = virtqueue_dequeue(vq, &len);
1803 		if (m == NULL)
1804 			break;
1805 		deq++;
1806 
1807 		if (len < sc->vtnet_hdr_size + ETHER_HDR_LEN) {
1808 			rxq->vtnrx_stats.vrxs_ierrors++;
1809 			vtnet_rxq_discard_buf(rxq, m);
1810 			continue;
1811 		}
1812 
1813 		if ((sc->vtnet_flags & VTNET_FLAG_MRG_RXBUFS) == 0) {
1814 			nbufs = 1;
1815 			adjsz = sizeof(struct vtnet_rx_header);
1816 			/*
1817 			 * Account for our pad inserted between the header
1818 			 * and the actual start of the frame.
1819 			 */
1820 			len += VTNET_RX_HEADER_PAD;
1821 		} else {
1822 			mhdr = mtod(m, struct virtio_net_hdr_mrg_rxbuf *);
1823 			nbufs = mhdr->num_buffers;
1824 			adjsz = sizeof(struct virtio_net_hdr_mrg_rxbuf);
1825 		}
1826 
1827 		/*
1828 		 * If we have enough data in first mbuf, run it through
1829 		 * pfil as a memory buffer before dequeueing the rest.
1830 		 */
1831 		if (PFIL_HOOKED_IN(sc->vtnet_pfil) &&
1832 		    len - adjsz >= ETHER_HDR_LEN + max_protohdr) {
1833 			pfil = pfil_run_hooks(sc->vtnet_pfil,
1834 			    m->m_data + adjsz, ifp,
1835 			    (len - adjsz) | PFIL_MEMPTR | PFIL_IN, NULL);
1836 			switch (pfil) {
1837 			case PFIL_REALLOCED:
1838 				mr = pfil_mem2mbuf(m->m_data + adjsz);
1839 				vtnet_rxq_input(rxq, mr, hdr);
1840 				/* FALLTHROUGH */
1841 			case PFIL_DROPPED:
1842 			case PFIL_CONSUMED:
1843 				vtnet_rxq_discard_buf(rxq, m);
1844 				if (nbufs > 1)
1845 					vtnet_rxq_discard_merged_bufs(rxq,
1846 					    nbufs);
1847 				continue;
1848 			default:
1849 				KASSERT(pfil == PFIL_PASS,
1850 				    ("Filter returned %d!\n", pfil));
1851 			};
1852 			pfil_done = true;
1853 		} else
1854 			pfil_done = false;
1855 
1856 		if (vtnet_rxq_replace_buf(rxq, m, len) != 0) {
1857 			rxq->vtnrx_stats.vrxs_iqdrops++;
1858 			vtnet_rxq_discard_buf(rxq, m);
1859 			if (nbufs > 1)
1860 				vtnet_rxq_discard_merged_bufs(rxq, nbufs);
1861 			continue;
1862 		}
1863 
1864 		m->m_pkthdr.len = len;
1865 		m->m_pkthdr.rcvif = ifp;
1866 		m->m_pkthdr.csum_flags = 0;
1867 
1868 		if (nbufs > 1) {
1869 			/* Dequeue the rest of chain. */
1870 			if (vtnet_rxq_merged_eof(rxq, m, nbufs) != 0)
1871 				continue;
1872 		}
1873 
1874 		/*
1875 		 * Save copy of header before we strip it. For both mergeable
1876 		 * and non-mergeable, the header is at the beginning of the
1877 		 * mbuf data. We no longer need num_buffers, so always use a
1878 		 * regular header.
1879 		 *
1880 		 * BMV: Is this memcpy() expensive? We know the mbuf data is
1881 		 * still valid even after the m_adj().
1882 		 */
1883 		memcpy(hdr, mtod(m, void *), sizeof(struct virtio_net_hdr));
1884 		m_adj(m, adjsz);
1885 
1886 		if (PFIL_HOOKED_IN(sc->vtnet_pfil) && pfil_done == false) {
1887 			pfil = pfil_run_hooks(sc->vtnet_pfil, &m, ifp, PFIL_IN,
1888 			    NULL);
1889 			switch (pfil) {
1890 			case PFIL_DROPPED:
1891 			case PFIL_CONSUMED:
1892 				continue;
1893 			default:
1894 				KASSERT(pfil == PFIL_PASS,
1895 				    ("Filter returned %d!\n", pfil));
1896 			}
1897 		}
1898 
1899 		vtnet_rxq_input(rxq, m, hdr);
1900 
1901 		/* Must recheck after dropping the Rx lock. */
1902 		if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0)
1903 			break;
1904 	}
1905 
1906 	if (deq > 0)
1907 		virtqueue_notify(vq);
1908 
1909 	return (count > 0 ? 0 : EAGAIN);
1910 }
1911 
1912 static void
1913 vtnet_rx_vq_intr(void *xrxq)
1914 {
1915 	struct vtnet_softc *sc;
1916 	struct vtnet_rxq *rxq;
1917 	struct ifnet *ifp;
1918 	int tries, more;
1919 
1920 	rxq = xrxq;
1921 	sc = rxq->vtnrx_sc;
1922 	ifp = sc->vtnet_ifp;
1923 	tries = 0;
1924 
1925 	if (__predict_false(rxq->vtnrx_id >= sc->vtnet_act_vq_pairs)) {
1926 		/*
1927 		 * Ignore this interrupt. Either this is a spurious interrupt
1928 		 * or multiqueue without per-VQ MSIX so every queue needs to
1929 		 * be polled (a brain dead configuration we could try harder
1930 		 * to avoid).
1931 		 */
1932 		vtnet_rxq_disable_intr(rxq);
1933 		return;
1934 	}
1935 
1936 #ifdef DEV_NETMAP
1937 	if (netmap_rx_irq(ifp, rxq->vtnrx_id, &more) != NM_IRQ_PASS)
1938 		return;
1939 #endif /* DEV_NETMAP */
1940 
1941 	VTNET_RXQ_LOCK(rxq);
1942 
1943 again:
1944 	if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) {
1945 		VTNET_RXQ_UNLOCK(rxq);
1946 		return;
1947 	}
1948 
1949 	more = vtnet_rxq_eof(rxq);
1950 	if (more || vtnet_rxq_enable_intr(rxq) != 0) {
1951 		if (!more)
1952 			vtnet_rxq_disable_intr(rxq);
1953 		/*
1954 		 * This is an occasional condition or race (when !more),
1955 		 * so retry a few times before scheduling the taskqueue.
1956 		 */
1957 		if (tries++ < VTNET_INTR_DISABLE_RETRIES)
1958 			goto again;
1959 
1960 		VTNET_RXQ_UNLOCK(rxq);
1961 		rxq->vtnrx_stats.vrxs_rescheduled++;
1962 		taskqueue_enqueue(rxq->vtnrx_tq, &rxq->vtnrx_intrtask);
1963 	} else
1964 		VTNET_RXQ_UNLOCK(rxq);
1965 }
1966 
1967 static void
1968 vtnet_rxq_tq_intr(void *xrxq, int pending)
1969 {
1970 	struct vtnet_softc *sc;
1971 	struct vtnet_rxq *rxq;
1972 	struct ifnet *ifp;
1973 	int more;
1974 
1975 	rxq = xrxq;
1976 	sc = rxq->vtnrx_sc;
1977 	ifp = sc->vtnet_ifp;
1978 
1979 	VTNET_RXQ_LOCK(rxq);
1980 
1981 	if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) {
1982 		VTNET_RXQ_UNLOCK(rxq);
1983 		return;
1984 	}
1985 
1986 	more = vtnet_rxq_eof(rxq);
1987 	if (more || vtnet_rxq_enable_intr(rxq) != 0) {
1988 		if (!more)
1989 			vtnet_rxq_disable_intr(rxq);
1990 		rxq->vtnrx_stats.vrxs_rescheduled++;
1991 		taskqueue_enqueue(rxq->vtnrx_tq, &rxq->vtnrx_intrtask);
1992 	}
1993 
1994 	VTNET_RXQ_UNLOCK(rxq);
1995 }
1996 
1997 static int
1998 vtnet_txq_below_threshold(struct vtnet_txq *txq)
1999 {
2000 	struct vtnet_softc *sc;
2001 	struct virtqueue *vq;
2002 
2003 	sc = txq->vtntx_sc;
2004 	vq = txq->vtntx_vq;
2005 
2006 	return (virtqueue_nfree(vq) <= sc->vtnet_tx_intr_thresh);
2007 }
2008 
2009 static int
2010 vtnet_txq_notify(struct vtnet_txq *txq)
2011 {
2012 	struct virtqueue *vq;
2013 
2014 	vq = txq->vtntx_vq;
2015 
2016 	txq->vtntx_watchdog = VTNET_TX_TIMEOUT;
2017 	virtqueue_notify(vq);
2018 
2019 	if (vtnet_txq_enable_intr(txq) == 0)
2020 		return (0);
2021 
2022 	/*
2023 	 * Drain frames that were completed since last checked. If this
2024 	 * causes the queue to go above the threshold, the caller should
2025 	 * continue transmitting.
2026 	 */
2027 	if (vtnet_txq_eof(txq) != 0 && vtnet_txq_below_threshold(txq) == 0) {
2028 		virtqueue_disable_intr(vq);
2029 		return (1);
2030 	}
2031 
2032 	return (0);
2033 }
2034 
2035 static void
2036 vtnet_txq_free_mbufs(struct vtnet_txq *txq)
2037 {
2038 	struct virtqueue *vq;
2039 	struct vtnet_tx_header *txhdr;
2040 	int last;
2041 #ifdef DEV_NETMAP
2042 	int netmap_bufs = vtnet_netmap_queue_on(txq->vtntx_sc, NR_TX,
2043 						txq->vtntx_id);
2044 #else  /* !DEV_NETMAP */
2045 	int netmap_bufs = 0;
2046 #endif /* !DEV_NETMAP */
2047 
2048 	vq = txq->vtntx_vq;
2049 	last = 0;
2050 
2051 	while ((txhdr = virtqueue_drain(vq, &last)) != NULL) {
2052 		if (!netmap_bufs) {
2053 			m_freem(txhdr->vth_mbuf);
2054 			uma_zfree(vtnet_tx_header_zone, txhdr);
2055 		}
2056 	}
2057 
2058 	KASSERT(virtqueue_empty(vq),
2059 	    ("%s: mbufs remaining in tx queue %p", __func__, txq));
2060 }
2061 
2062 /*
2063  * BMV: Much of this can go away once we finally have offsets in
2064  * the mbuf packet header. Bug andre@.
2065  */
2066 static int
2067 vtnet_txq_offload_ctx(struct vtnet_txq *txq, struct mbuf *m,
2068     int *etype, int *proto, int *start)
2069 {
2070 	struct vtnet_softc *sc;
2071 	struct ether_vlan_header *evh;
2072 	int offset;
2073 
2074 	sc = txq->vtntx_sc;
2075 
2076 	evh = mtod(m, struct ether_vlan_header *);
2077 	if (evh->evl_encap_proto == htons(ETHERTYPE_VLAN)) {
2078 		/* BMV: We should handle nested VLAN tags too. */
2079 		*etype = ntohs(evh->evl_proto);
2080 		offset = sizeof(struct ether_vlan_header);
2081 	} else {
2082 		*etype = ntohs(evh->evl_encap_proto);
2083 		offset = sizeof(struct ether_header);
2084 	}
2085 
2086 	switch (*etype) {
2087 #if defined(INET)
2088 	case ETHERTYPE_IP: {
2089 		struct ip *ip, iphdr;
2090 		if (__predict_false(m->m_len < offset + sizeof(struct ip))) {
2091 			m_copydata(m, offset, sizeof(struct ip),
2092 			    (caddr_t) &iphdr);
2093 			ip = &iphdr;
2094 		} else
2095 			ip = (struct ip *)(m->m_data + offset);
2096 		*proto = ip->ip_p;
2097 		*start = offset + (ip->ip_hl << 2);
2098 		break;
2099 	}
2100 #endif
2101 #if defined(INET6)
2102 	case ETHERTYPE_IPV6:
2103 		*proto = -1;
2104 		*start = ip6_lasthdr(m, offset, IPPROTO_IPV6, proto);
2105 		/* Assert the network stack sent us a valid packet. */
2106 		KASSERT(*start > offset,
2107 		    ("%s: mbuf %p start %d offset %d proto %d", __func__, m,
2108 		    *start, offset, *proto));
2109 		break;
2110 #endif
2111 	default:
2112 		sc->vtnet_stats.tx_csum_bad_ethtype++;
2113 		return (EINVAL);
2114 	}
2115 
2116 	return (0);
2117 }
2118 
2119 static int
2120 vtnet_txq_offload_tso(struct vtnet_txq *txq, struct mbuf *m, int eth_type,
2121     int offset, struct virtio_net_hdr *hdr)
2122 {
2123 	static struct timeval lastecn;
2124 	static int curecn;
2125 	struct vtnet_softc *sc;
2126 	struct tcphdr *tcp, tcphdr;
2127 
2128 	sc = txq->vtntx_sc;
2129 
2130 	if (__predict_false(m->m_len < offset + sizeof(struct tcphdr))) {
2131 		m_copydata(m, offset, sizeof(struct tcphdr), (caddr_t) &tcphdr);
2132 		tcp = &tcphdr;
2133 	} else
2134 		tcp = (struct tcphdr *)(m->m_data + offset);
2135 
2136 	hdr->hdr_len = offset + (tcp->th_off << 2);
2137 	hdr->gso_size = m->m_pkthdr.tso_segsz;
2138 	hdr->gso_type = eth_type == ETHERTYPE_IP ? VIRTIO_NET_HDR_GSO_TCPV4 :
2139 	    VIRTIO_NET_HDR_GSO_TCPV6;
2140 
2141 	if (tcp->th_flags & TH_CWR) {
2142 		/*
2143 		 * Drop if VIRTIO_NET_F_HOST_ECN was not negotiated. In FreeBSD,
2144 		 * ECN support is not on a per-interface basis, but globally via
2145 		 * the net.inet.tcp.ecn.enable sysctl knob. The default is off.
2146 		 */
2147 		if ((sc->vtnet_flags & VTNET_FLAG_TSO_ECN) == 0) {
2148 			if (ppsratecheck(&lastecn, &curecn, 1))
2149 				if_printf(sc->vtnet_ifp,
2150 				    "TSO with ECN not negotiated with host\n");
2151 			return (ENOTSUP);
2152 		}
2153 		hdr->gso_type |= VIRTIO_NET_HDR_GSO_ECN;
2154 	}
2155 
2156 	txq->vtntx_stats.vtxs_tso++;
2157 
2158 	return (0);
2159 }
2160 
2161 static struct mbuf *
2162 vtnet_txq_offload(struct vtnet_txq *txq, struct mbuf *m,
2163     struct virtio_net_hdr *hdr)
2164 {
2165 	struct vtnet_softc *sc;
2166 	int flags, etype, csum_start, proto, error;
2167 
2168 	sc = txq->vtntx_sc;
2169 	flags = m->m_pkthdr.csum_flags;
2170 
2171 	error = vtnet_txq_offload_ctx(txq, m, &etype, &proto, &csum_start);
2172 	if (error)
2173 		goto drop;
2174 
2175 	if ((etype == ETHERTYPE_IP && flags & VTNET_CSUM_OFFLOAD) ||
2176 	    (etype == ETHERTYPE_IPV6 && flags & VTNET_CSUM_OFFLOAD_IPV6)) {
2177 		/*
2178 		 * We could compare the IP protocol vs the CSUM_ flag too,
2179 		 * but that really should not be necessary.
2180 		 */
2181 		hdr->flags |= VIRTIO_NET_HDR_F_NEEDS_CSUM;
2182 		hdr->csum_start = csum_start;
2183 		hdr->csum_offset = m->m_pkthdr.csum_data;
2184 		txq->vtntx_stats.vtxs_csum++;
2185 	}
2186 
2187 	if (flags & CSUM_TSO) {
2188 		if (__predict_false(proto != IPPROTO_TCP)) {
2189 			/* Likely failed to correctly parse the mbuf. */
2190 			sc->vtnet_stats.tx_tso_not_tcp++;
2191 			goto drop;
2192 		}
2193 
2194 		KASSERT(hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM,
2195 		    ("%s: mbuf %p TSO without checksum offload %#x",
2196 		    __func__, m, flags));
2197 
2198 		error = vtnet_txq_offload_tso(txq, m, etype, csum_start, hdr);
2199 		if (error)
2200 			goto drop;
2201 	}
2202 
2203 	return (m);
2204 
2205 drop:
2206 	m_freem(m);
2207 	return (NULL);
2208 }
2209 
2210 static int
2211 vtnet_txq_enqueue_buf(struct vtnet_txq *txq, struct mbuf **m_head,
2212     struct vtnet_tx_header *txhdr)
2213 {
2214 	struct vtnet_softc *sc;
2215 	struct virtqueue *vq;
2216 	struct sglist *sg;
2217 	struct mbuf *m;
2218 	int error;
2219 
2220 	sc = txq->vtntx_sc;
2221 	vq = txq->vtntx_vq;
2222 	sg = txq->vtntx_sg;
2223 	m = *m_head;
2224 
2225 	sglist_reset(sg);
2226 	error = sglist_append(sg, &txhdr->vth_uhdr, sc->vtnet_hdr_size);
2227 	KASSERT(error == 0 && sg->sg_nseg == 1,
2228 	    ("%s: error %d adding header to sglist", __func__, error));
2229 
2230 	error = sglist_append_mbuf(sg, m);
2231 	if (error) {
2232 		m = m_defrag(m, M_NOWAIT);
2233 		if (m == NULL)
2234 			goto fail;
2235 
2236 		*m_head = m;
2237 		sc->vtnet_stats.tx_defragged++;
2238 
2239 		error = sglist_append_mbuf(sg, m);
2240 		if (error)
2241 			goto fail;
2242 	}
2243 
2244 	txhdr->vth_mbuf = m;
2245 	error = virtqueue_enqueue(vq, txhdr, sg, sg->sg_nseg, 0);
2246 
2247 	return (error);
2248 
2249 fail:
2250 	sc->vtnet_stats.tx_defrag_failed++;
2251 	m_freem(*m_head);
2252 	*m_head = NULL;
2253 
2254 	return (ENOBUFS);
2255 }
2256 
2257 static int
2258 vtnet_txq_encap(struct vtnet_txq *txq, struct mbuf **m_head, int flags)
2259 {
2260 	struct vtnet_tx_header *txhdr;
2261 	struct virtio_net_hdr *hdr;
2262 	struct mbuf *m;
2263 	int error;
2264 
2265 	m = *m_head;
2266 	M_ASSERTPKTHDR(m);
2267 
2268 	txhdr = uma_zalloc(vtnet_tx_header_zone, flags | M_ZERO);
2269 	if (txhdr == NULL) {
2270 		m_freem(m);
2271 		*m_head = NULL;
2272 		return (ENOMEM);
2273 	}
2274 
2275 	/*
2276 	 * Always use the non-mergeable header, regardless if the feature
2277 	 * was negotiated. For transmit, num_buffers is always zero. The
2278 	 * vtnet_hdr_size is used to enqueue the correct header size.
2279 	 */
2280 	hdr = &txhdr->vth_uhdr.hdr;
2281 
2282 	if (m->m_flags & M_VLANTAG) {
2283 		m = ether_vlanencap(m, m->m_pkthdr.ether_vtag);
2284 		if ((*m_head = m) == NULL) {
2285 			error = ENOBUFS;
2286 			goto fail;
2287 		}
2288 		m->m_flags &= ~M_VLANTAG;
2289 	}
2290 
2291 	if (m->m_pkthdr.csum_flags & VTNET_CSUM_ALL_OFFLOAD) {
2292 		m = vtnet_txq_offload(txq, m, hdr);
2293 		if ((*m_head = m) == NULL) {
2294 			error = ENOBUFS;
2295 			goto fail;
2296 		}
2297 	}
2298 
2299 	error = vtnet_txq_enqueue_buf(txq, m_head, txhdr);
2300 	if (error == 0)
2301 		return (0);
2302 
2303 fail:
2304 	uma_zfree(vtnet_tx_header_zone, txhdr);
2305 
2306 	return (error);
2307 }
2308 
2309 #ifdef VTNET_LEGACY_TX
2310 
2311 static void
2312 vtnet_start_locked(struct vtnet_txq *txq, struct ifnet *ifp)
2313 {
2314 	struct vtnet_softc *sc;
2315 	struct virtqueue *vq;
2316 	struct mbuf *m0;
2317 	int tries, enq;
2318 
2319 	sc = txq->vtntx_sc;
2320 	vq = txq->vtntx_vq;
2321 	tries = 0;
2322 
2323 	VTNET_TXQ_LOCK_ASSERT(txq);
2324 
2325 	if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
2326 	    sc->vtnet_link_active == 0)
2327 		return;
2328 
2329 	vtnet_txq_eof(txq);
2330 
2331 again:
2332 	enq = 0;
2333 
2334 	while (!IFQ_DRV_IS_EMPTY(&ifp->if_snd)) {
2335 		if (virtqueue_full(vq))
2336 			break;
2337 
2338 		IFQ_DRV_DEQUEUE(&ifp->if_snd, m0);
2339 		if (m0 == NULL)
2340 			break;
2341 
2342 		if (vtnet_txq_encap(txq, &m0, M_NOWAIT) != 0) {
2343 			if (m0 != NULL)
2344 				IFQ_DRV_PREPEND(&ifp->if_snd, m0);
2345 			break;
2346 		}
2347 
2348 		enq++;
2349 		ETHER_BPF_MTAP(ifp, m0);
2350 	}
2351 
2352 	if (enq > 0 && vtnet_txq_notify(txq) != 0) {
2353 		if (tries++ < VTNET_NOTIFY_RETRIES)
2354 			goto again;
2355 
2356 		txq->vtntx_stats.vtxs_rescheduled++;
2357 		taskqueue_enqueue(txq->vtntx_tq, &txq->vtntx_intrtask);
2358 	}
2359 }
2360 
2361 static void
2362 vtnet_start(struct ifnet *ifp)
2363 {
2364 	struct vtnet_softc *sc;
2365 	struct vtnet_txq *txq;
2366 
2367 	sc = ifp->if_softc;
2368 	txq = &sc->vtnet_txqs[0];
2369 
2370 	VTNET_TXQ_LOCK(txq);
2371 	vtnet_start_locked(txq, ifp);
2372 	VTNET_TXQ_UNLOCK(txq);
2373 }
2374 
2375 #else /* !VTNET_LEGACY_TX */
2376 
2377 static int
2378 vtnet_txq_mq_start_locked(struct vtnet_txq *txq, struct mbuf *m)
2379 {
2380 	struct vtnet_softc *sc;
2381 	struct virtqueue *vq;
2382 	struct buf_ring *br;
2383 	struct ifnet *ifp;
2384 	int enq, tries, error;
2385 
2386 	sc = txq->vtntx_sc;
2387 	vq = txq->vtntx_vq;
2388 	br = txq->vtntx_br;
2389 	ifp = sc->vtnet_ifp;
2390 	tries = 0;
2391 	error = 0;
2392 
2393 	VTNET_TXQ_LOCK_ASSERT(txq);
2394 
2395 	if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
2396 	    sc->vtnet_link_active == 0) {
2397 		if (m != NULL)
2398 			error = drbr_enqueue(ifp, br, m);
2399 		return (error);
2400 	}
2401 
2402 	if (m != NULL) {
2403 		error = drbr_enqueue(ifp, br, m);
2404 		if (error)
2405 			return (error);
2406 	}
2407 
2408 	vtnet_txq_eof(txq);
2409 
2410 again:
2411 	enq = 0;
2412 
2413 	while ((m = drbr_peek(ifp, br)) != NULL) {
2414 		if (virtqueue_full(vq)) {
2415 			drbr_putback(ifp, br, m);
2416 			break;
2417 		}
2418 
2419 		if (vtnet_txq_encap(txq, &m, M_NOWAIT) != 0) {
2420 			if (m != NULL)
2421 				drbr_putback(ifp, br, m);
2422 			else
2423 				drbr_advance(ifp, br);
2424 			break;
2425 		}
2426 		drbr_advance(ifp, br);
2427 
2428 		enq++;
2429 		ETHER_BPF_MTAP(ifp, m);
2430 	}
2431 
2432 	if (enq > 0 && vtnet_txq_notify(txq) != 0) {
2433 		if (tries++ < VTNET_NOTIFY_RETRIES)
2434 			goto again;
2435 
2436 		txq->vtntx_stats.vtxs_rescheduled++;
2437 		taskqueue_enqueue(txq->vtntx_tq, &txq->vtntx_intrtask);
2438 	}
2439 
2440 	return (0);
2441 }
2442 
2443 static int
2444 vtnet_txq_mq_start(struct ifnet *ifp, struct mbuf *m)
2445 {
2446 	struct vtnet_softc *sc;
2447 	struct vtnet_txq *txq;
2448 	int i, npairs, error;
2449 
2450 	sc = ifp->if_softc;
2451 	npairs = sc->vtnet_act_vq_pairs;
2452 
2453 	/* check if flowid is set */
2454 	if (M_HASHTYPE_GET(m) != M_HASHTYPE_NONE)
2455 		i = m->m_pkthdr.flowid % npairs;
2456 	else
2457 		i = curcpu % npairs;
2458 
2459 	txq = &sc->vtnet_txqs[i];
2460 
2461 	if (VTNET_TXQ_TRYLOCK(txq) != 0) {
2462 		error = vtnet_txq_mq_start_locked(txq, m);
2463 		VTNET_TXQ_UNLOCK(txq);
2464 	} else {
2465 		error = drbr_enqueue(ifp, txq->vtntx_br, m);
2466 		taskqueue_enqueue(txq->vtntx_tq, &txq->vtntx_defrtask);
2467 	}
2468 
2469 	return (error);
2470 }
2471 
2472 static void
2473 vtnet_txq_tq_deferred(void *xtxq, int pending)
2474 {
2475 	struct vtnet_softc *sc;
2476 	struct vtnet_txq *txq;
2477 
2478 	txq = xtxq;
2479 	sc = txq->vtntx_sc;
2480 
2481 	VTNET_TXQ_LOCK(txq);
2482 	if (!drbr_empty(sc->vtnet_ifp, txq->vtntx_br))
2483 		vtnet_txq_mq_start_locked(txq, NULL);
2484 	VTNET_TXQ_UNLOCK(txq);
2485 }
2486 
2487 #endif /* VTNET_LEGACY_TX */
2488 
2489 static void
2490 vtnet_txq_start(struct vtnet_txq *txq)
2491 {
2492 	struct vtnet_softc *sc;
2493 	struct ifnet *ifp;
2494 
2495 	sc = txq->vtntx_sc;
2496 	ifp = sc->vtnet_ifp;
2497 
2498 #ifdef VTNET_LEGACY_TX
2499 	if (!IFQ_DRV_IS_EMPTY(&ifp->if_snd))
2500 		vtnet_start_locked(txq, ifp);
2501 #else
2502 	if (!drbr_empty(ifp, txq->vtntx_br))
2503 		vtnet_txq_mq_start_locked(txq, NULL);
2504 #endif
2505 }
2506 
2507 static void
2508 vtnet_txq_tq_intr(void *xtxq, int pending)
2509 {
2510 	struct vtnet_softc *sc;
2511 	struct vtnet_txq *txq;
2512 	struct ifnet *ifp;
2513 
2514 	txq = xtxq;
2515 	sc = txq->vtntx_sc;
2516 	ifp = sc->vtnet_ifp;
2517 
2518 	VTNET_TXQ_LOCK(txq);
2519 
2520 	if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) {
2521 		VTNET_TXQ_UNLOCK(txq);
2522 		return;
2523 	}
2524 
2525 	vtnet_txq_eof(txq);
2526 	vtnet_txq_start(txq);
2527 
2528 	VTNET_TXQ_UNLOCK(txq);
2529 }
2530 
2531 static int
2532 vtnet_txq_eof(struct vtnet_txq *txq)
2533 {
2534 	struct virtqueue *vq;
2535 	struct vtnet_tx_header *txhdr;
2536 	struct mbuf *m;
2537 	int deq;
2538 
2539 	vq = txq->vtntx_vq;
2540 	deq = 0;
2541 	VTNET_TXQ_LOCK_ASSERT(txq);
2542 
2543 	while ((txhdr = virtqueue_dequeue(vq, NULL)) != NULL) {
2544 		m = txhdr->vth_mbuf;
2545 		deq++;
2546 
2547 		txq->vtntx_stats.vtxs_opackets++;
2548 		txq->vtntx_stats.vtxs_obytes += m->m_pkthdr.len;
2549 		if (m->m_flags & M_MCAST)
2550 			txq->vtntx_stats.vtxs_omcasts++;
2551 
2552 		m_freem(m);
2553 		uma_zfree(vtnet_tx_header_zone, txhdr);
2554 	}
2555 
2556 	if (virtqueue_empty(vq))
2557 		txq->vtntx_watchdog = 0;
2558 
2559 	return (deq);
2560 }
2561 
2562 static void
2563 vtnet_tx_vq_intr(void *xtxq)
2564 {
2565 	struct vtnet_softc *sc;
2566 	struct vtnet_txq *txq;
2567 	struct ifnet *ifp;
2568 
2569 	txq = xtxq;
2570 	sc = txq->vtntx_sc;
2571 	ifp = sc->vtnet_ifp;
2572 
2573 	if (__predict_false(txq->vtntx_id >= sc->vtnet_act_vq_pairs)) {
2574 		/*
2575 		 * Ignore this interrupt. Either this is a spurious interrupt
2576 		 * or multiqueue without per-VQ MSIX so every queue needs to
2577 		 * be polled (a brain dead configuration we could try harder
2578 		 * to avoid).
2579 		 */
2580 		vtnet_txq_disable_intr(txq);
2581 		return;
2582 	}
2583 
2584 #ifdef DEV_NETMAP
2585 	if (netmap_tx_irq(ifp, txq->vtntx_id) != NM_IRQ_PASS)
2586 		return;
2587 #endif /* DEV_NETMAP */
2588 
2589 	VTNET_TXQ_LOCK(txq);
2590 
2591 	if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) {
2592 		VTNET_TXQ_UNLOCK(txq);
2593 		return;
2594 	}
2595 
2596 	vtnet_txq_eof(txq);
2597 	vtnet_txq_start(txq);
2598 
2599 	VTNET_TXQ_UNLOCK(txq);
2600 }
2601 
2602 static void
2603 vtnet_tx_start_all(struct vtnet_softc *sc)
2604 {
2605 	struct vtnet_txq *txq;
2606 	int i;
2607 
2608 	VTNET_CORE_LOCK_ASSERT(sc);
2609 
2610 	for (i = 0; i < sc->vtnet_act_vq_pairs; i++) {
2611 		txq = &sc->vtnet_txqs[i];
2612 
2613 		VTNET_TXQ_LOCK(txq);
2614 		vtnet_txq_start(txq);
2615 		VTNET_TXQ_UNLOCK(txq);
2616 	}
2617 }
2618 
2619 #ifndef VTNET_LEGACY_TX
2620 static void
2621 vtnet_qflush(struct ifnet *ifp)
2622 {
2623 	struct vtnet_softc *sc;
2624 	struct vtnet_txq *txq;
2625 	struct mbuf *m;
2626 	int i;
2627 
2628 	sc = ifp->if_softc;
2629 
2630 	for (i = 0; i < sc->vtnet_act_vq_pairs; i++) {
2631 		txq = &sc->vtnet_txqs[i];
2632 
2633 		VTNET_TXQ_LOCK(txq);
2634 		while ((m = buf_ring_dequeue_sc(txq->vtntx_br)) != NULL)
2635 			m_freem(m);
2636 		VTNET_TXQ_UNLOCK(txq);
2637 	}
2638 
2639 	if_qflush(ifp);
2640 }
2641 #endif
2642 
2643 static int
2644 vtnet_watchdog(struct vtnet_txq *txq)
2645 {
2646 	struct ifnet *ifp;
2647 
2648 	ifp = txq->vtntx_sc->vtnet_ifp;
2649 
2650 	VTNET_TXQ_LOCK(txq);
2651 	if (txq->vtntx_watchdog == 1) {
2652 		/*
2653 		 * Only drain completed frames if the watchdog is about to
2654 		 * expire. If any frames were drained, there may be enough
2655 		 * free descriptors now available to transmit queued frames.
2656 		 * In that case, the timer will immediately be decremented
2657 		 * below, but the timeout is generous enough that should not
2658 		 * be a problem.
2659 		 */
2660 		if (vtnet_txq_eof(txq) != 0)
2661 			vtnet_txq_start(txq);
2662 	}
2663 
2664 	if (txq->vtntx_watchdog == 0 || --txq->vtntx_watchdog) {
2665 		VTNET_TXQ_UNLOCK(txq);
2666 		return (0);
2667 	}
2668 	VTNET_TXQ_UNLOCK(txq);
2669 
2670 	if_printf(ifp, "watchdog timeout on queue %d\n", txq->vtntx_id);
2671 	return (1);
2672 }
2673 
2674 static void
2675 vtnet_accum_stats(struct vtnet_softc *sc, struct vtnet_rxq_stats *rxacc,
2676     struct vtnet_txq_stats *txacc)
2677 {
2678 
2679 	bzero(rxacc, sizeof(struct vtnet_rxq_stats));
2680 	bzero(txacc, sizeof(struct vtnet_txq_stats));
2681 
2682 	for (int i = 0; i < sc->vtnet_max_vq_pairs; i++) {
2683 		struct vtnet_rxq_stats *rxst;
2684 		struct vtnet_txq_stats *txst;
2685 
2686 		rxst = &sc->vtnet_rxqs[i].vtnrx_stats;
2687 		rxacc->vrxs_ipackets += rxst->vrxs_ipackets;
2688 		rxacc->vrxs_ibytes += rxst->vrxs_ibytes;
2689 		rxacc->vrxs_iqdrops += rxst->vrxs_iqdrops;
2690 		rxacc->vrxs_csum += rxst->vrxs_csum;
2691 		rxacc->vrxs_csum_failed += rxst->vrxs_csum_failed;
2692 		rxacc->vrxs_rescheduled += rxst->vrxs_rescheduled;
2693 
2694 		txst = &sc->vtnet_txqs[i].vtntx_stats;
2695 		txacc->vtxs_opackets += txst->vtxs_opackets;
2696 		txacc->vtxs_obytes += txst->vtxs_obytes;
2697 		txacc->vtxs_csum += txst->vtxs_csum;
2698 		txacc->vtxs_tso += txst->vtxs_tso;
2699 		txacc->vtxs_rescheduled += txst->vtxs_rescheduled;
2700 	}
2701 }
2702 
2703 static uint64_t
2704 vtnet_get_counter(if_t ifp, ift_counter cnt)
2705 {
2706 	struct vtnet_softc *sc;
2707 	struct vtnet_rxq_stats rxaccum;
2708 	struct vtnet_txq_stats txaccum;
2709 
2710 	sc = if_getsoftc(ifp);
2711 	vtnet_accum_stats(sc, &rxaccum, &txaccum);
2712 
2713 	switch (cnt) {
2714 	case IFCOUNTER_IPACKETS:
2715 		return (rxaccum.vrxs_ipackets);
2716 	case IFCOUNTER_IQDROPS:
2717 		return (rxaccum.vrxs_iqdrops);
2718 	case IFCOUNTER_IERRORS:
2719 		return (rxaccum.vrxs_ierrors);
2720 	case IFCOUNTER_OPACKETS:
2721 		return (txaccum.vtxs_opackets);
2722 #ifndef VTNET_LEGACY_TX
2723 	case IFCOUNTER_OBYTES:
2724 		return (txaccum.vtxs_obytes);
2725 	case IFCOUNTER_OMCASTS:
2726 		return (txaccum.vtxs_omcasts);
2727 #endif
2728 	default:
2729 		return (if_get_counter_default(ifp, cnt));
2730 	}
2731 }
2732 
2733 static void
2734 vtnet_tick(void *xsc)
2735 {
2736 	struct vtnet_softc *sc;
2737 	struct ifnet *ifp;
2738 	int i, timedout;
2739 
2740 	sc = xsc;
2741 	ifp = sc->vtnet_ifp;
2742 	timedout = 0;
2743 
2744 	VTNET_CORE_LOCK_ASSERT(sc);
2745 
2746 	for (i = 0; i < sc->vtnet_act_vq_pairs; i++)
2747 		timedout |= vtnet_watchdog(&sc->vtnet_txqs[i]);
2748 
2749 	if (timedout != 0) {
2750 		ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
2751 		vtnet_init_locked(sc);
2752 	} else
2753 		callout_schedule(&sc->vtnet_tick_ch, hz);
2754 }
2755 
2756 static void
2757 vtnet_start_taskqueues(struct vtnet_softc *sc)
2758 {
2759 	device_t dev;
2760 	struct vtnet_rxq *rxq;
2761 	struct vtnet_txq *txq;
2762 	int i, error;
2763 
2764 	dev = sc->vtnet_dev;
2765 
2766 	/*
2767 	 * Errors here are very difficult to recover from - we cannot
2768 	 * easily fail because, if this is during boot, we will hang
2769 	 * when freeing any successfully started taskqueues because
2770 	 * the scheduler isn't up yet.
2771 	 *
2772 	 * Most drivers just ignore the return value - it only fails
2773 	 * with ENOMEM so an error is not likely.
2774 	 */
2775 	for (i = 0; i < sc->vtnet_max_vq_pairs; i++) {
2776 		rxq = &sc->vtnet_rxqs[i];
2777 		error = taskqueue_start_threads(&rxq->vtnrx_tq, 1, PI_NET,
2778 		    "%s rxq %d", device_get_nameunit(dev), rxq->vtnrx_id);
2779 		if (error) {
2780 			device_printf(dev, "failed to start rx taskq %d\n",
2781 			    rxq->vtnrx_id);
2782 		}
2783 
2784 		txq = &sc->vtnet_txqs[i];
2785 		error = taskqueue_start_threads(&txq->vtntx_tq, 1, PI_NET,
2786 		    "%s txq %d", device_get_nameunit(dev), txq->vtntx_id);
2787 		if (error) {
2788 			device_printf(dev, "failed to start tx taskq %d\n",
2789 			    txq->vtntx_id);
2790 		}
2791 	}
2792 }
2793 
2794 static void
2795 vtnet_free_taskqueues(struct vtnet_softc *sc)
2796 {
2797 	struct vtnet_rxq *rxq;
2798 	struct vtnet_txq *txq;
2799 	int i;
2800 
2801 	for (i = 0; i < sc->vtnet_max_vq_pairs; i++) {
2802 		rxq = &sc->vtnet_rxqs[i];
2803 		if (rxq->vtnrx_tq != NULL) {
2804 			taskqueue_free(rxq->vtnrx_tq);
2805 			rxq->vtnrx_tq = NULL;
2806 		}
2807 
2808 		txq = &sc->vtnet_txqs[i];
2809 		if (txq->vtntx_tq != NULL) {
2810 			taskqueue_free(txq->vtntx_tq);
2811 			txq->vtntx_tq = NULL;
2812 		}
2813 	}
2814 }
2815 
2816 static void
2817 vtnet_drain_taskqueues(struct vtnet_softc *sc)
2818 {
2819 	struct vtnet_rxq *rxq;
2820 	struct vtnet_txq *txq;
2821 	int i;
2822 
2823 	for (i = 0; i < sc->vtnet_max_vq_pairs; i++) {
2824 		rxq = &sc->vtnet_rxqs[i];
2825 		if (rxq->vtnrx_tq != NULL)
2826 			taskqueue_drain(rxq->vtnrx_tq, &rxq->vtnrx_intrtask);
2827 
2828 		txq = &sc->vtnet_txqs[i];
2829 		if (txq->vtntx_tq != NULL) {
2830 			taskqueue_drain(txq->vtntx_tq, &txq->vtntx_intrtask);
2831 #ifndef VTNET_LEGACY_TX
2832 			taskqueue_drain(txq->vtntx_tq, &txq->vtntx_defrtask);
2833 #endif
2834 		}
2835 	}
2836 }
2837 
2838 static void
2839 vtnet_drain_rxtx_queues(struct vtnet_softc *sc)
2840 {
2841 	struct vtnet_rxq *rxq;
2842 	struct vtnet_txq *txq;
2843 	int i;
2844 
2845 	for (i = 0; i < sc->vtnet_act_vq_pairs; i++) {
2846 		rxq = &sc->vtnet_rxqs[i];
2847 		vtnet_rxq_free_mbufs(rxq);
2848 
2849 		txq = &sc->vtnet_txqs[i];
2850 		vtnet_txq_free_mbufs(txq);
2851 	}
2852 }
2853 
2854 static void
2855 vtnet_stop_rendezvous(struct vtnet_softc *sc)
2856 {
2857 	struct vtnet_rxq *rxq;
2858 	struct vtnet_txq *txq;
2859 	int i;
2860 
2861 	/*
2862 	 * Lock and unlock the per-queue mutex so we known the stop
2863 	 * state is visible. Doing only the active queues should be
2864 	 * sufficient, but it does not cost much extra to do all the
2865 	 * queues. Note we hold the core mutex here too.
2866 	 */
2867 	for (i = 0; i < sc->vtnet_max_vq_pairs; i++) {
2868 		rxq = &sc->vtnet_rxqs[i];
2869 		VTNET_RXQ_LOCK(rxq);
2870 		VTNET_RXQ_UNLOCK(rxq);
2871 
2872 		txq = &sc->vtnet_txqs[i];
2873 		VTNET_TXQ_LOCK(txq);
2874 		VTNET_TXQ_UNLOCK(txq);
2875 	}
2876 }
2877 
2878 static void
2879 vtnet_stop(struct vtnet_softc *sc)
2880 {
2881 	device_t dev;
2882 	struct ifnet *ifp;
2883 
2884 	dev = sc->vtnet_dev;
2885 	ifp = sc->vtnet_ifp;
2886 
2887 	VTNET_CORE_LOCK_ASSERT(sc);
2888 
2889 	ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
2890 	sc->vtnet_link_active = 0;
2891 	callout_stop(&sc->vtnet_tick_ch);
2892 
2893 	/* Only advisory. */
2894 	vtnet_disable_interrupts(sc);
2895 
2896 	/*
2897 	 * Stop the host adapter. This resets it to the pre-initialized
2898 	 * state. It will not generate any interrupts until after it is
2899 	 * reinitialized.
2900 	 */
2901 	virtio_stop(dev);
2902 	vtnet_stop_rendezvous(sc);
2903 
2904 	/* Free any mbufs left in the virtqueues. */
2905 	vtnet_drain_rxtx_queues(sc);
2906 }
2907 
2908 static int
2909 vtnet_virtio_reinit(struct vtnet_softc *sc)
2910 {
2911 	device_t dev;
2912 	struct ifnet *ifp;
2913 	uint64_t features;
2914 	int mask, error;
2915 
2916 	dev = sc->vtnet_dev;
2917 	ifp = sc->vtnet_ifp;
2918 	features = sc->vtnet_features;
2919 
2920 	mask = 0;
2921 #if defined(INET)
2922 	mask |= IFCAP_RXCSUM;
2923 #endif
2924 #if defined (INET6)
2925 	mask |= IFCAP_RXCSUM_IPV6;
2926 #endif
2927 
2928 	/*
2929 	 * Re-negotiate with the host, removing any disabled receive
2930 	 * features. Transmit features are disabled only on our side
2931 	 * via if_capenable and if_hwassist.
2932 	 */
2933 
2934 	if (ifp->if_capabilities & mask) {
2935 		/*
2936 		 * We require both IPv4 and IPv6 offloading to be enabled
2937 		 * in order to negotiated it: VirtIO does not distinguish
2938 		 * between the two.
2939 		 */
2940 		if ((ifp->if_capenable & mask) != mask)
2941 			features &= ~VIRTIO_NET_F_GUEST_CSUM;
2942 	}
2943 
2944 	if (ifp->if_capabilities & IFCAP_LRO) {
2945 		if ((ifp->if_capenable & IFCAP_LRO) == 0)
2946 			features &= ~VTNET_LRO_FEATURES;
2947 	}
2948 
2949 	if (ifp->if_capabilities & IFCAP_VLAN_HWFILTER) {
2950 		if ((ifp->if_capenable & IFCAP_VLAN_HWFILTER) == 0)
2951 			features &= ~VIRTIO_NET_F_CTRL_VLAN;
2952 	}
2953 
2954 	error = virtio_reinit(dev, features);
2955 	if (error)
2956 		device_printf(dev, "virtio reinit error %d\n", error);
2957 
2958 	return (error);
2959 }
2960 
2961 static void
2962 vtnet_init_rx_filters(struct vtnet_softc *sc)
2963 {
2964 	struct ifnet *ifp;
2965 
2966 	ifp = sc->vtnet_ifp;
2967 
2968 	if (sc->vtnet_flags & VTNET_FLAG_CTRL_RX) {
2969 		/* Restore promiscuous and all-multicast modes. */
2970 		vtnet_rx_filter(sc);
2971 		/* Restore filtered MAC addresses. */
2972 		vtnet_rx_filter_mac(sc);
2973 	}
2974 
2975 	if (ifp->if_capenable & IFCAP_VLAN_HWFILTER)
2976 		vtnet_rx_filter_vlan(sc);
2977 }
2978 
2979 static int
2980 vtnet_init_rx_queues(struct vtnet_softc *sc)
2981 {
2982 	device_t dev;
2983 	struct vtnet_rxq *rxq;
2984 	int i, clsize, error;
2985 
2986 	dev = sc->vtnet_dev;
2987 
2988 	/*
2989 	 * Use the new cluster size if one has been set (via a MTU
2990 	 * change). Otherwise, use the standard 2K clusters.
2991 	 *
2992 	 * BMV: It might make sense to use page sized clusters as
2993 	 * the default (depending on the features negotiated).
2994 	 */
2995 	if (sc->vtnet_rx_new_clsize != 0) {
2996 		clsize = sc->vtnet_rx_new_clsize;
2997 		sc->vtnet_rx_new_clsize = 0;
2998 	} else
2999 		clsize = MCLBYTES;
3000 
3001 	sc->vtnet_rx_clsize = clsize;
3002 	sc->vtnet_rx_nmbufs = VTNET_NEEDED_RX_MBUFS(sc, clsize);
3003 
3004 	KASSERT(sc->vtnet_flags & VTNET_FLAG_MRG_RXBUFS ||
3005 	    sc->vtnet_rx_nmbufs < sc->vtnet_rx_nsegs,
3006 	    ("%s: too many rx mbufs %d for %d segments", __func__,
3007 	    sc->vtnet_rx_nmbufs, sc->vtnet_rx_nsegs));
3008 
3009 	for (i = 0; i < sc->vtnet_act_vq_pairs; i++) {
3010 		rxq = &sc->vtnet_rxqs[i];
3011 
3012 		/* Hold the lock to satisfy asserts. */
3013 		VTNET_RXQ_LOCK(rxq);
3014 		error = vtnet_rxq_populate(rxq);
3015 		VTNET_RXQ_UNLOCK(rxq);
3016 
3017 		if (error) {
3018 			device_printf(dev,
3019 			    "cannot allocate mbufs for Rx queue %d\n", i);
3020 			return (error);
3021 		}
3022 	}
3023 
3024 	return (0);
3025 }
3026 
3027 static int
3028 vtnet_init_tx_queues(struct vtnet_softc *sc)
3029 {
3030 	struct vtnet_txq *txq;
3031 	int i;
3032 
3033 	for (i = 0; i < sc->vtnet_act_vq_pairs; i++) {
3034 		txq = &sc->vtnet_txqs[i];
3035 		txq->vtntx_watchdog = 0;
3036 	}
3037 
3038 	return (0);
3039 }
3040 
3041 static int
3042 vtnet_init_rxtx_queues(struct vtnet_softc *sc)
3043 {
3044 	int error;
3045 
3046 	error = vtnet_init_rx_queues(sc);
3047 	if (error)
3048 		return (error);
3049 
3050 	error = vtnet_init_tx_queues(sc);
3051 	if (error)
3052 		return (error);
3053 
3054 	return (0);
3055 }
3056 
3057 static void
3058 vtnet_set_active_vq_pairs(struct vtnet_softc *sc)
3059 {
3060 	device_t dev;
3061 	int npairs;
3062 
3063 	dev = sc->vtnet_dev;
3064 
3065 	if ((sc->vtnet_flags & VTNET_FLAG_MULTIQ) == 0) {
3066 		sc->vtnet_act_vq_pairs = 1;
3067 		return;
3068 	}
3069 
3070 	npairs = sc->vtnet_requested_vq_pairs;
3071 
3072 	if (vtnet_ctrl_mq_cmd(sc, npairs) != 0) {
3073 		device_printf(dev,
3074 		    "cannot set active queue pairs to %d\n", npairs);
3075 		npairs = 1;
3076 	}
3077 
3078 	sc->vtnet_act_vq_pairs = npairs;
3079 }
3080 
3081 static int
3082 vtnet_reinit(struct vtnet_softc *sc)
3083 {
3084 	struct ifnet *ifp;
3085 	int error;
3086 
3087 	ifp = sc->vtnet_ifp;
3088 
3089 	/* Use the current MAC address. */
3090 	bcopy(IF_LLADDR(ifp), sc->vtnet_hwaddr, ETHER_ADDR_LEN);
3091 	vtnet_set_hwaddr(sc);
3092 
3093 	vtnet_set_active_vq_pairs(sc);
3094 
3095 	ifp->if_hwassist = 0;
3096 	if (ifp->if_capenable & IFCAP_TXCSUM)
3097 		ifp->if_hwassist |= VTNET_CSUM_OFFLOAD;
3098 	if (ifp->if_capenable & IFCAP_TXCSUM_IPV6)
3099 		ifp->if_hwassist |= VTNET_CSUM_OFFLOAD_IPV6;
3100 	if (ifp->if_capenable & IFCAP_TSO4)
3101 		ifp->if_hwassist |= CSUM_IP_TSO;
3102 	if (ifp->if_capenable & IFCAP_TSO6)
3103 		ifp->if_hwassist |= CSUM_IP6_TSO;
3104 
3105 	if (sc->vtnet_flags & VTNET_FLAG_CTRL_VQ)
3106 		vtnet_init_rx_filters(sc);
3107 
3108 	error = vtnet_init_rxtx_queues(sc);
3109 	if (error)
3110 		return (error);
3111 
3112 	vtnet_enable_interrupts(sc);
3113 	ifp->if_drv_flags |= IFF_DRV_RUNNING;
3114 
3115 	return (0);
3116 }
3117 
3118 static void
3119 vtnet_init_locked(struct vtnet_softc *sc)
3120 {
3121 	device_t dev;
3122 	struct ifnet *ifp;
3123 
3124 	dev = sc->vtnet_dev;
3125 	ifp = sc->vtnet_ifp;
3126 
3127 	VTNET_CORE_LOCK_ASSERT(sc);
3128 
3129 	if (ifp->if_drv_flags & IFF_DRV_RUNNING)
3130 		return;
3131 
3132 	vtnet_stop(sc);
3133 
3134 	/* Reinitialize with the host. */
3135 	if (vtnet_virtio_reinit(sc) != 0)
3136 		goto fail;
3137 
3138 	if (vtnet_reinit(sc) != 0)
3139 		goto fail;
3140 
3141 	virtio_reinit_complete(dev);
3142 
3143 	vtnet_update_link_status(sc);
3144 	callout_reset(&sc->vtnet_tick_ch, hz, vtnet_tick, sc);
3145 
3146 	return;
3147 
3148 fail:
3149 	vtnet_stop(sc);
3150 }
3151 
3152 static void
3153 vtnet_init(void *xsc)
3154 {
3155 	struct vtnet_softc *sc;
3156 
3157 	sc = xsc;
3158 
3159 	VTNET_CORE_LOCK(sc);
3160 	vtnet_init_locked(sc);
3161 	VTNET_CORE_UNLOCK(sc);
3162 }
3163 
3164 static void
3165 vtnet_free_ctrl_vq(struct vtnet_softc *sc)
3166 {
3167 	struct virtqueue *vq;
3168 
3169 	vq = sc->vtnet_ctrl_vq;
3170 
3171 	/*
3172 	 * The control virtqueue is only polled and therefore it should
3173 	 * already be empty.
3174 	 */
3175 	KASSERT(virtqueue_empty(vq),
3176 	    ("%s: ctrl vq %p not empty", __func__, vq));
3177 }
3178 
3179 static void
3180 vtnet_exec_ctrl_cmd(struct vtnet_softc *sc, void *cookie,
3181     struct sglist *sg, int readable, int writable)
3182 {
3183 	struct virtqueue *vq;
3184 
3185 	vq = sc->vtnet_ctrl_vq;
3186 
3187 	VTNET_CORE_LOCK_ASSERT(sc);
3188 	KASSERT(sc->vtnet_flags & VTNET_FLAG_CTRL_VQ,
3189 	    ("%s: CTRL_VQ feature not negotiated", __func__));
3190 
3191 	if (!virtqueue_empty(vq))
3192 		return;
3193 	if (virtqueue_enqueue(vq, cookie, sg, readable, writable) != 0)
3194 		return;
3195 
3196 	/*
3197 	 * Poll for the response, but the command is likely already
3198 	 * done when we return from the notify.
3199 	 */
3200 	virtqueue_notify(vq);
3201 	virtqueue_poll(vq, NULL);
3202 }
3203 
3204 static int
3205 vtnet_ctrl_mac_cmd(struct vtnet_softc *sc, uint8_t *hwaddr)
3206 {
3207 	struct virtio_net_ctrl_hdr hdr __aligned(2);
3208 	struct sglist_seg segs[3];
3209 	struct sglist sg;
3210 	uint8_t ack;
3211 	int error;
3212 
3213 	hdr.class = VIRTIO_NET_CTRL_MAC;
3214 	hdr.cmd = VIRTIO_NET_CTRL_MAC_ADDR_SET;
3215 	ack = VIRTIO_NET_ERR;
3216 
3217 	sglist_init(&sg, 3, segs);
3218 	error = 0;
3219 	error |= sglist_append(&sg, &hdr, sizeof(struct virtio_net_ctrl_hdr));
3220 	error |= sglist_append(&sg, hwaddr, ETHER_ADDR_LEN);
3221 	error |= sglist_append(&sg, &ack, sizeof(uint8_t));
3222 	KASSERT(error == 0 && sg.sg_nseg == 3,
3223 	    ("%s: error %d adding set MAC msg to sglist", __func__, error));
3224 
3225 	vtnet_exec_ctrl_cmd(sc, &ack, &sg, sg.sg_nseg - 1, 1);
3226 
3227 	return (ack == VIRTIO_NET_OK ? 0 : EIO);
3228 }
3229 
3230 static int
3231 vtnet_ctrl_mq_cmd(struct vtnet_softc *sc, uint16_t npairs)
3232 {
3233 	struct sglist_seg segs[3];
3234 	struct sglist sg;
3235 	struct {
3236 		struct virtio_net_ctrl_hdr hdr;
3237 		uint8_t pad1;
3238 		struct virtio_net_ctrl_mq mq;
3239 		uint8_t pad2;
3240 		uint8_t ack;
3241 	} s __aligned(2);
3242 	int error;
3243 
3244 	s.hdr.class = VIRTIO_NET_CTRL_MQ;
3245 	s.hdr.cmd = VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET;
3246 	s.mq.virtqueue_pairs = npairs;
3247 	s.ack = VIRTIO_NET_ERR;
3248 
3249 	sglist_init(&sg, 3, segs);
3250 	error = 0;
3251 	error |= sglist_append(&sg, &s.hdr, sizeof(struct virtio_net_ctrl_hdr));
3252 	error |= sglist_append(&sg, &s.mq, sizeof(struct virtio_net_ctrl_mq));
3253 	error |= sglist_append(&sg, &s.ack, sizeof(uint8_t));
3254 	KASSERT(error == 0 && sg.sg_nseg == 3,
3255 	    ("%s: error %d adding MQ message to sglist", __func__, error));
3256 
3257 	vtnet_exec_ctrl_cmd(sc, &s.ack, &sg, sg.sg_nseg - 1, 1);
3258 
3259 	return (s.ack == VIRTIO_NET_OK ? 0 : EIO);
3260 }
3261 
3262 static int
3263 vtnet_ctrl_rx_cmd(struct vtnet_softc *sc, int cmd, int on)
3264 {
3265 	struct sglist_seg segs[3];
3266 	struct sglist sg;
3267 	struct {
3268 		struct virtio_net_ctrl_hdr hdr;
3269 		uint8_t pad1;
3270 		uint8_t onoff;
3271 		uint8_t pad2;
3272 		uint8_t ack;
3273 	} s __aligned(2);
3274 	int error;
3275 
3276 	KASSERT(sc->vtnet_flags & VTNET_FLAG_CTRL_RX,
3277 	    ("%s: CTRL_RX feature not negotiated", __func__));
3278 
3279 	s.hdr.class = VIRTIO_NET_CTRL_RX;
3280 	s.hdr.cmd = cmd;
3281 	s.onoff = !!on;
3282 	s.ack = VIRTIO_NET_ERR;
3283 
3284 	sglist_init(&sg, 3, segs);
3285 	error = 0;
3286 	error |= sglist_append(&sg, &s.hdr, sizeof(struct virtio_net_ctrl_hdr));
3287 	error |= sglist_append(&sg, &s.onoff, sizeof(uint8_t));
3288 	error |= sglist_append(&sg, &s.ack, sizeof(uint8_t));
3289 	KASSERT(error == 0 && sg.sg_nseg == 3,
3290 	    ("%s: error %d adding Rx message to sglist", __func__, error));
3291 
3292 	vtnet_exec_ctrl_cmd(sc, &s.ack, &sg, sg.sg_nseg - 1, 1);
3293 
3294 	return (s.ack == VIRTIO_NET_OK ? 0 : EIO);
3295 }
3296 
3297 static int
3298 vtnet_set_promisc(struct vtnet_softc *sc, int on)
3299 {
3300 
3301 	return (vtnet_ctrl_rx_cmd(sc, VIRTIO_NET_CTRL_RX_PROMISC, on));
3302 }
3303 
3304 static int
3305 vtnet_set_allmulti(struct vtnet_softc *sc, int on)
3306 {
3307 
3308 	return (vtnet_ctrl_rx_cmd(sc, VIRTIO_NET_CTRL_RX_ALLMULTI, on));
3309 }
3310 
3311 /*
3312  * The device defaults to promiscuous mode for backwards compatibility.
3313  * Turn it off at attach time if possible.
3314  */
3315 static void
3316 vtnet_attach_disable_promisc(struct vtnet_softc *sc)
3317 {
3318 	struct ifnet *ifp;
3319 
3320 	ifp = sc->vtnet_ifp;
3321 
3322 	VTNET_CORE_LOCK(sc);
3323 	if ((sc->vtnet_flags & VTNET_FLAG_CTRL_RX) == 0) {
3324 		ifp->if_flags |= IFF_PROMISC;
3325 	} else if (vtnet_set_promisc(sc, 0) != 0) {
3326 		ifp->if_flags |= IFF_PROMISC;
3327 		device_printf(sc->vtnet_dev,
3328 		    "cannot disable default promiscuous mode\n");
3329 	}
3330 	VTNET_CORE_UNLOCK(sc);
3331 }
3332 
3333 static void
3334 vtnet_rx_filter(struct vtnet_softc *sc)
3335 {
3336 	device_t dev;
3337 	struct ifnet *ifp;
3338 
3339 	dev = sc->vtnet_dev;
3340 	ifp = sc->vtnet_ifp;
3341 
3342 	VTNET_CORE_LOCK_ASSERT(sc);
3343 
3344 	if (vtnet_set_promisc(sc, ifp->if_flags & IFF_PROMISC) != 0)
3345 		device_printf(dev, "cannot %s promiscuous mode\n",
3346 		    ifp->if_flags & IFF_PROMISC ? "enable" : "disable");
3347 
3348 	if (vtnet_set_allmulti(sc, ifp->if_flags & IFF_ALLMULTI) != 0)
3349 		device_printf(dev, "cannot %s all-multicast mode\n",
3350 		    ifp->if_flags & IFF_ALLMULTI ? "enable" : "disable");
3351 }
3352 
3353 static u_int
3354 vtnet_copy_ifaddr(void *arg, struct sockaddr_dl *sdl, u_int ucnt)
3355 {
3356 	struct vtnet_softc *sc = arg;
3357 
3358 	if (memcmp(LLADDR(sdl), sc->vtnet_hwaddr, ETHER_ADDR_LEN) == 0)
3359 		return (0);
3360 
3361 	if (ucnt < VTNET_MAX_MAC_ENTRIES)
3362 		bcopy(LLADDR(sdl),
3363 		    &sc->vtnet_mac_filter->vmf_unicast.macs[ucnt],
3364 		    ETHER_ADDR_LEN);
3365 
3366 	return (1);
3367 }
3368 
3369 static u_int
3370 vtnet_copy_maddr(void *arg, struct sockaddr_dl *sdl, u_int mcnt)
3371 {
3372 	struct vtnet_mac_filter *filter = arg;
3373 
3374 	if (mcnt < VTNET_MAX_MAC_ENTRIES)
3375 		bcopy(LLADDR(sdl), &filter->vmf_multicast.macs[mcnt],
3376 		    ETHER_ADDR_LEN);
3377 
3378 	return (1);
3379 }
3380 
3381 static void
3382 vtnet_rx_filter_mac(struct vtnet_softc *sc)
3383 {
3384 	struct virtio_net_ctrl_hdr hdr __aligned(2);
3385 	struct vtnet_mac_filter *filter;
3386 	struct sglist_seg segs[4];
3387 	struct sglist sg;
3388 	struct ifnet *ifp;
3389 	bool promisc, allmulti;
3390 	u_int ucnt, mcnt;
3391 	int error;
3392 	uint8_t ack;
3393 
3394 	ifp = sc->vtnet_ifp;
3395 	filter = sc->vtnet_mac_filter;
3396 
3397 	VTNET_CORE_LOCK_ASSERT(sc);
3398 	KASSERT(sc->vtnet_flags & VTNET_FLAG_CTRL_RX,
3399 	    ("%s: CTRL_RX feature not negotiated", __func__));
3400 
3401 	/* Unicast MAC addresses: */
3402 	ucnt = if_foreach_lladdr(ifp, vtnet_copy_ifaddr, sc);
3403 	promisc = (ucnt > VTNET_MAX_MAC_ENTRIES);
3404 
3405 	if (promisc) {
3406 		filter->vmf_unicast.nentries = 0;
3407 		if_printf(ifp, "more than %d MAC addresses assigned, "
3408 		    "falling back to promiscuous mode\n",
3409 		    VTNET_MAX_MAC_ENTRIES);
3410 	} else
3411 		filter->vmf_unicast.nentries = ucnt;
3412 
3413 	/* Multicast MAC addresses: */
3414 	mcnt = if_foreach_llmaddr(ifp, vtnet_copy_maddr, filter);
3415 	allmulti = (mcnt > VTNET_MAX_MAC_ENTRIES);
3416 
3417 	if (allmulti) {
3418 		filter->vmf_multicast.nentries = 0;
3419 		if_printf(ifp, "more than %d multicast MAC addresses "
3420 		    "assigned, falling back to all-multicast mode\n",
3421 		    VTNET_MAX_MAC_ENTRIES);
3422 	} else
3423 		filter->vmf_multicast.nentries = mcnt;
3424 
3425 	if (promisc && allmulti)
3426 		goto out;
3427 
3428 	hdr.class = VIRTIO_NET_CTRL_MAC;
3429 	hdr.cmd = VIRTIO_NET_CTRL_MAC_TABLE_SET;
3430 	ack = VIRTIO_NET_ERR;
3431 
3432 	sglist_init(&sg, 4, segs);
3433 	error = 0;
3434 	error |= sglist_append(&sg, &hdr, sizeof(struct virtio_net_ctrl_hdr));
3435 	error |= sglist_append(&sg, &filter->vmf_unicast,
3436 	    sizeof(uint32_t) + filter->vmf_unicast.nentries * ETHER_ADDR_LEN);
3437 	error |= sglist_append(&sg, &filter->vmf_multicast,
3438 	    sizeof(uint32_t) + filter->vmf_multicast.nentries * ETHER_ADDR_LEN);
3439 	error |= sglist_append(&sg, &ack, sizeof(uint8_t));
3440 	KASSERT(error == 0 && sg.sg_nseg == 4,
3441 	    ("%s: error %d adding MAC filter msg to sglist", __func__, error));
3442 
3443 	vtnet_exec_ctrl_cmd(sc, &ack, &sg, sg.sg_nseg - 1, 1);
3444 
3445 	if (ack != VIRTIO_NET_OK)
3446 		if_printf(ifp, "error setting host MAC filter table\n");
3447 
3448 out:
3449 	if (promisc != 0 && vtnet_set_promisc(sc, 1) != 0)
3450 		if_printf(ifp, "cannot enable promiscuous mode\n");
3451 	if (allmulti != 0 && vtnet_set_allmulti(sc, 1) != 0)
3452 		if_printf(ifp, "cannot enable all-multicast mode\n");
3453 }
3454 
3455 static int
3456 vtnet_exec_vlan_filter(struct vtnet_softc *sc, int add, uint16_t tag)
3457 {
3458 	struct sglist_seg segs[3];
3459 	struct sglist sg;
3460 	struct {
3461 		struct virtio_net_ctrl_hdr hdr;
3462 		uint8_t pad1;
3463 		uint16_t tag;
3464 		uint8_t pad2;
3465 		uint8_t ack;
3466 	} s __aligned(2);
3467 	int error;
3468 
3469 	s.hdr.class = VIRTIO_NET_CTRL_VLAN;
3470 	s.hdr.cmd = add ? VIRTIO_NET_CTRL_VLAN_ADD : VIRTIO_NET_CTRL_VLAN_DEL;
3471 	s.tag = tag;
3472 	s.ack = VIRTIO_NET_ERR;
3473 
3474 	sglist_init(&sg, 3, segs);
3475 	error = 0;
3476 	error |= sglist_append(&sg, &s.hdr, sizeof(struct virtio_net_ctrl_hdr));
3477 	error |= sglist_append(&sg, &s.tag, sizeof(uint16_t));
3478 	error |= sglist_append(&sg, &s.ack, sizeof(uint8_t));
3479 	KASSERT(error == 0 && sg.sg_nseg == 3,
3480 	    ("%s: error %d adding VLAN message to sglist", __func__, error));
3481 
3482 	vtnet_exec_ctrl_cmd(sc, &s.ack, &sg, sg.sg_nseg - 1, 1);
3483 
3484 	return (s.ack == VIRTIO_NET_OK ? 0 : EIO);
3485 }
3486 
3487 static void
3488 vtnet_rx_filter_vlan(struct vtnet_softc *sc)
3489 {
3490 	uint32_t w;
3491 	uint16_t tag;
3492 	int i, bit;
3493 
3494 	VTNET_CORE_LOCK_ASSERT(sc);
3495 	KASSERT(sc->vtnet_flags & VTNET_FLAG_VLAN_FILTER,
3496 	    ("%s: VLAN_FILTER feature not negotiated", __func__));
3497 
3498 	/* Enable the filter for each configured VLAN. */
3499 	for (i = 0; i < VTNET_VLAN_FILTER_NWORDS; i++) {
3500 		w = sc->vtnet_vlan_filter[i];
3501 
3502 		while ((bit = ffs(w) - 1) != -1) {
3503 			w &= ~(1 << bit);
3504 			tag = sizeof(w) * CHAR_BIT * i + bit;
3505 
3506 			if (vtnet_exec_vlan_filter(sc, 1, tag) != 0) {
3507 				device_printf(sc->vtnet_dev,
3508 				    "cannot enable VLAN %d filter\n", tag);
3509 			}
3510 		}
3511 	}
3512 }
3513 
3514 static void
3515 vtnet_update_vlan_filter(struct vtnet_softc *sc, int add, uint16_t tag)
3516 {
3517 	struct ifnet *ifp;
3518 	int idx, bit;
3519 
3520 	ifp = sc->vtnet_ifp;
3521 	idx = (tag >> 5) & 0x7F;
3522 	bit = tag & 0x1F;
3523 
3524 	if (tag == 0 || tag > 4095)
3525 		return;
3526 
3527 	VTNET_CORE_LOCK(sc);
3528 
3529 	if (add)
3530 		sc->vtnet_vlan_filter[idx] |= (1 << bit);
3531 	else
3532 		sc->vtnet_vlan_filter[idx] &= ~(1 << bit);
3533 
3534 	if (ifp->if_capenable & IFCAP_VLAN_HWFILTER &&
3535 	    ifp->if_drv_flags & IFF_DRV_RUNNING &&
3536 	    vtnet_exec_vlan_filter(sc, add, tag) != 0) {
3537 		device_printf(sc->vtnet_dev,
3538 		    "cannot %s VLAN %d %s the host filter table\n",
3539 		    add ? "add" : "remove", tag, add ? "to" : "from");
3540 	}
3541 
3542 	VTNET_CORE_UNLOCK(sc);
3543 }
3544 
3545 static void
3546 vtnet_register_vlan(void *arg, struct ifnet *ifp, uint16_t tag)
3547 {
3548 
3549 	if (ifp->if_softc != arg)
3550 		return;
3551 
3552 	vtnet_update_vlan_filter(arg, 1, tag);
3553 }
3554 
3555 static void
3556 vtnet_unregister_vlan(void *arg, struct ifnet *ifp, uint16_t tag)
3557 {
3558 
3559 	if (ifp->if_softc != arg)
3560 		return;
3561 
3562 	vtnet_update_vlan_filter(arg, 0, tag);
3563 }
3564 
3565 static int
3566 vtnet_is_link_up(struct vtnet_softc *sc)
3567 {
3568 	device_t dev;
3569 	struct ifnet *ifp;
3570 	uint16_t status;
3571 
3572 	dev = sc->vtnet_dev;
3573 	ifp = sc->vtnet_ifp;
3574 
3575 	if ((ifp->if_capabilities & IFCAP_LINKSTATE) == 0)
3576 		status = VIRTIO_NET_S_LINK_UP;
3577 	else
3578 		status = virtio_read_dev_config_2(dev,
3579 		    offsetof(struct virtio_net_config, status));
3580 
3581 	return ((status & VIRTIO_NET_S_LINK_UP) != 0);
3582 }
3583 
3584 static void
3585 vtnet_update_link_status(struct vtnet_softc *sc)
3586 {
3587 	struct ifnet *ifp;
3588 	int link;
3589 
3590 	ifp = sc->vtnet_ifp;
3591 
3592 	VTNET_CORE_LOCK_ASSERT(sc);
3593 	link = vtnet_is_link_up(sc);
3594 
3595 	/* Notify if the link status has changed. */
3596 	if (link != 0 && sc->vtnet_link_active == 0) {
3597 		sc->vtnet_link_active = 1;
3598 		if_link_state_change(ifp, LINK_STATE_UP);
3599 	} else if (link == 0 && sc->vtnet_link_active != 0) {
3600 		sc->vtnet_link_active = 0;
3601 		if_link_state_change(ifp, LINK_STATE_DOWN);
3602 	}
3603 }
3604 
3605 static int
3606 vtnet_ifmedia_upd(struct ifnet *ifp)
3607 {
3608 	struct vtnet_softc *sc;
3609 	struct ifmedia *ifm;
3610 
3611 	sc = ifp->if_softc;
3612 	ifm = &sc->vtnet_media;
3613 
3614 	if (IFM_TYPE(ifm->ifm_media) != IFM_ETHER)
3615 		return (EINVAL);
3616 
3617 	return (0);
3618 }
3619 
3620 static void
3621 vtnet_ifmedia_sts(struct ifnet *ifp, struct ifmediareq *ifmr)
3622 {
3623 	struct vtnet_softc *sc;
3624 
3625 	sc = ifp->if_softc;
3626 
3627 	ifmr->ifm_status = IFM_AVALID;
3628 	ifmr->ifm_active = IFM_ETHER;
3629 
3630 	VTNET_CORE_LOCK(sc);
3631 	if (vtnet_is_link_up(sc) != 0) {
3632 		ifmr->ifm_status |= IFM_ACTIVE;
3633 		ifmr->ifm_active |= VTNET_MEDIATYPE;
3634 	} else
3635 		ifmr->ifm_active |= IFM_NONE;
3636 	VTNET_CORE_UNLOCK(sc);
3637 }
3638 
3639 static void
3640 vtnet_set_hwaddr(struct vtnet_softc *sc)
3641 {
3642 	device_t dev;
3643 	int i;
3644 
3645 	dev = sc->vtnet_dev;
3646 
3647 	if (sc->vtnet_flags & VTNET_FLAG_CTRL_MAC) {
3648 		if (vtnet_ctrl_mac_cmd(sc, sc->vtnet_hwaddr) != 0)
3649 			device_printf(dev, "unable to set MAC address\n");
3650 	} else if (sc->vtnet_flags & VTNET_FLAG_MAC) {
3651 		for (i = 0; i < ETHER_ADDR_LEN; i++) {
3652 			virtio_write_dev_config_1(dev,
3653 			    offsetof(struct virtio_net_config, mac) + i,
3654 			    sc->vtnet_hwaddr[i]);
3655 		}
3656 	}
3657 }
3658 
3659 static void
3660 vtnet_get_hwaddr(struct vtnet_softc *sc)
3661 {
3662 	device_t dev;
3663 	int i;
3664 
3665 	dev = sc->vtnet_dev;
3666 
3667 	if ((sc->vtnet_flags & VTNET_FLAG_MAC) == 0) {
3668 		/*
3669 		 * Generate a random locally administered unicast address.
3670 		 *
3671 		 * It would be nice to generate the same MAC address across
3672 		 * reboots, but it seems all the hosts currently available
3673 		 * support the MAC feature, so this isn't too important.
3674 		 */
3675 		sc->vtnet_hwaddr[0] = 0xB2;
3676 		arc4rand(&sc->vtnet_hwaddr[1], ETHER_ADDR_LEN - 1, 0);
3677 		vtnet_set_hwaddr(sc);
3678 		return;
3679 	}
3680 
3681 	for (i = 0; i < ETHER_ADDR_LEN; i++) {
3682 		sc->vtnet_hwaddr[i] = virtio_read_dev_config_1(dev,
3683 		    offsetof(struct virtio_net_config, mac) + i);
3684 	}
3685 }
3686 
3687 static void
3688 vtnet_vlan_tag_remove(struct mbuf *m)
3689 {
3690 	struct ether_vlan_header *evh;
3691 
3692 	evh = mtod(m, struct ether_vlan_header *);
3693 	m->m_pkthdr.ether_vtag = ntohs(evh->evl_tag);
3694 	m->m_flags |= M_VLANTAG;
3695 
3696 	/* Strip the 802.1Q header. */
3697 	bcopy((char *) evh, (char *) evh + ETHER_VLAN_ENCAP_LEN,
3698 	    ETHER_HDR_LEN - ETHER_TYPE_LEN);
3699 	m_adj(m, ETHER_VLAN_ENCAP_LEN);
3700 }
3701 
3702 static void
3703 vtnet_set_rx_process_limit(struct vtnet_softc *sc)
3704 {
3705 	int limit;
3706 
3707 	limit = vtnet_tunable_int(sc, "rx_process_limit",
3708 	    vtnet_rx_process_limit);
3709 	if (limit < 0)
3710 		limit = INT_MAX;
3711 	sc->vtnet_rx_process_limit = limit;
3712 }
3713 
3714 static void
3715 vtnet_set_tx_intr_threshold(struct vtnet_softc *sc)
3716 {
3717 	int size, thresh;
3718 
3719 	size = virtqueue_size(sc->vtnet_txqs[0].vtntx_vq);
3720 
3721 	/*
3722 	 * The Tx interrupt is disabled until the queue free count falls
3723 	 * below our threshold. Completed frames are drained from the Tx
3724 	 * virtqueue before transmitting new frames and in the watchdog
3725 	 * callout, so the frequency of Tx interrupts is greatly reduced,
3726 	 * at the cost of not freeing mbufs as quickly as they otherwise
3727 	 * would be.
3728 	 *
3729 	 * N.B. We assume all the Tx queues are the same size.
3730 	 */
3731 	thresh = size / 4;
3732 
3733 	/*
3734 	 * Without indirect descriptors, leave enough room for the most
3735 	 * segments we handle.
3736 	 */
3737 	if ((sc->vtnet_flags & VTNET_FLAG_INDIRECT) == 0 &&
3738 	    thresh < sc->vtnet_tx_nsegs)
3739 		thresh = sc->vtnet_tx_nsegs;
3740 
3741 	sc->vtnet_tx_intr_thresh = thresh;
3742 }
3743 
3744 static void
3745 vtnet_setup_rxq_sysctl(struct sysctl_ctx_list *ctx,
3746     struct sysctl_oid_list *child, struct vtnet_rxq *rxq)
3747 {
3748 	struct sysctl_oid *node;
3749 	struct sysctl_oid_list *list;
3750 	struct vtnet_rxq_stats *stats;
3751 	char namebuf[16];
3752 
3753 	snprintf(namebuf, sizeof(namebuf), "rxq%d", rxq->vtnrx_id);
3754 	node = SYSCTL_ADD_NODE(ctx, child, OID_AUTO, namebuf,
3755 	    CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "Receive Queue");
3756 	list = SYSCTL_CHILDREN(node);
3757 
3758 	stats = &rxq->vtnrx_stats;
3759 
3760 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "ipackets", CTLFLAG_RD,
3761 	    &stats->vrxs_ipackets, "Receive packets");
3762 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "ibytes", CTLFLAG_RD,
3763 	    &stats->vrxs_ibytes, "Receive bytes");
3764 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "iqdrops", CTLFLAG_RD,
3765 	    &stats->vrxs_iqdrops, "Receive drops");
3766 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "ierrors", CTLFLAG_RD,
3767 	    &stats->vrxs_ierrors, "Receive errors");
3768 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "csum", CTLFLAG_RD,
3769 	    &stats->vrxs_csum, "Receive checksum offloaded");
3770 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "csum_failed", CTLFLAG_RD,
3771 	    &stats->vrxs_csum_failed, "Receive checksum offload failed");
3772 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "rescheduled", CTLFLAG_RD,
3773 	    &stats->vrxs_rescheduled,
3774 	    "Receive interrupt handler rescheduled");
3775 }
3776 
3777 static void
3778 vtnet_setup_txq_sysctl(struct sysctl_ctx_list *ctx,
3779     struct sysctl_oid_list *child, struct vtnet_txq *txq)
3780 {
3781 	struct sysctl_oid *node;
3782 	struct sysctl_oid_list *list;
3783 	struct vtnet_txq_stats *stats;
3784 	char namebuf[16];
3785 
3786 	snprintf(namebuf, sizeof(namebuf), "txq%d", txq->vtntx_id);
3787 	node = SYSCTL_ADD_NODE(ctx, child, OID_AUTO, namebuf,
3788 	    CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "Transmit Queue");
3789 	list = SYSCTL_CHILDREN(node);
3790 
3791 	stats = &txq->vtntx_stats;
3792 
3793 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "opackets", CTLFLAG_RD,
3794 	    &stats->vtxs_opackets, "Transmit packets");
3795 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "obytes", CTLFLAG_RD,
3796 	    &stats->vtxs_obytes, "Transmit bytes");
3797 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "omcasts", CTLFLAG_RD,
3798 	    &stats->vtxs_omcasts, "Transmit multicasts");
3799 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "csum", CTLFLAG_RD,
3800 	    &stats->vtxs_csum, "Transmit checksum offloaded");
3801 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "tso", CTLFLAG_RD,
3802 	    &stats->vtxs_tso, "Transmit segmentation offloaded");
3803 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "rescheduled", CTLFLAG_RD,
3804 	    &stats->vtxs_rescheduled,
3805 	    "Transmit interrupt handler rescheduled");
3806 }
3807 
3808 static void
3809 vtnet_setup_queue_sysctl(struct vtnet_softc *sc)
3810 {
3811 	device_t dev;
3812 	struct sysctl_ctx_list *ctx;
3813 	struct sysctl_oid *tree;
3814 	struct sysctl_oid_list *child;
3815 	int i;
3816 
3817 	dev = sc->vtnet_dev;
3818 	ctx = device_get_sysctl_ctx(dev);
3819 	tree = device_get_sysctl_tree(dev);
3820 	child = SYSCTL_CHILDREN(tree);
3821 
3822 	for (i = 0; i < sc->vtnet_max_vq_pairs; i++) {
3823 		vtnet_setup_rxq_sysctl(ctx, child, &sc->vtnet_rxqs[i]);
3824 		vtnet_setup_txq_sysctl(ctx, child, &sc->vtnet_txqs[i]);
3825 	}
3826 }
3827 
3828 static void
3829 vtnet_setup_stat_sysctl(struct sysctl_ctx_list *ctx,
3830     struct sysctl_oid_list *child, struct vtnet_softc *sc)
3831 {
3832 	struct vtnet_statistics *stats;
3833 	struct vtnet_rxq_stats rxaccum;
3834 	struct vtnet_txq_stats txaccum;
3835 
3836 	vtnet_accum_stats(sc, &rxaccum, &txaccum);
3837 
3838 	stats = &sc->vtnet_stats;
3839 	stats->rx_csum_offloaded = rxaccum.vrxs_csum;
3840 	stats->rx_csum_failed = rxaccum.vrxs_csum_failed;
3841 	stats->rx_task_rescheduled = rxaccum.vrxs_rescheduled;
3842 	stats->tx_csum_offloaded = txaccum.vtxs_csum;
3843 	stats->tx_tso_offloaded = txaccum.vtxs_tso;
3844 	stats->tx_task_rescheduled = txaccum.vtxs_rescheduled;
3845 
3846 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "mbuf_alloc_failed",
3847 	    CTLFLAG_RD, &stats->mbuf_alloc_failed,
3848 	    "Mbuf cluster allocation failures");
3849 
3850 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "rx_frame_too_large",
3851 	    CTLFLAG_RD, &stats->rx_frame_too_large,
3852 	    "Received frame larger than the mbuf chain");
3853 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "rx_enq_replacement_failed",
3854 	    CTLFLAG_RD, &stats->rx_enq_replacement_failed,
3855 	    "Enqueuing the replacement receive mbuf failed");
3856 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "rx_mergeable_failed",
3857 	    CTLFLAG_RD, &stats->rx_mergeable_failed,
3858 	    "Mergeable buffers receive failures");
3859 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "rx_csum_bad_ethtype",
3860 	    CTLFLAG_RD, &stats->rx_csum_bad_ethtype,
3861 	    "Received checksum offloaded buffer with unsupported "
3862 	    "Ethernet type");
3863 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "rx_csum_bad_ipproto",
3864 	    CTLFLAG_RD, &stats->rx_csum_bad_ipproto,
3865 	    "Received checksum offloaded buffer with incorrect IP protocol");
3866 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "rx_csum_bad_offset",
3867 	    CTLFLAG_RD, &stats->rx_csum_bad_offset,
3868 	    "Received checksum offloaded buffer with incorrect offset");
3869 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "rx_csum_bad_proto",
3870 	    CTLFLAG_RD, &stats->rx_csum_bad_proto,
3871 	    "Received checksum offloaded buffer with incorrect protocol");
3872 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "rx_csum_failed",
3873 	    CTLFLAG_RD, &stats->rx_csum_failed,
3874 	    "Received buffer checksum offload failed");
3875 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "rx_csum_offloaded",
3876 	    CTLFLAG_RD, &stats->rx_csum_offloaded,
3877 	    "Received buffer checksum offload succeeded");
3878 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "rx_task_rescheduled",
3879 	    CTLFLAG_RD, &stats->rx_task_rescheduled,
3880 	    "Times the receive interrupt task rescheduled itself");
3881 
3882 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "tx_csum_bad_ethtype",
3883 	    CTLFLAG_RD, &stats->tx_csum_bad_ethtype,
3884 	    "Aborted transmit of checksum offloaded buffer with unknown "
3885 	    "Ethernet type");
3886 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "tx_tso_bad_ethtype",
3887 	    CTLFLAG_RD, &stats->tx_tso_bad_ethtype,
3888 	    "Aborted transmit of TSO buffer with unknown Ethernet type");
3889 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "tx_tso_not_tcp",
3890 	    CTLFLAG_RD, &stats->tx_tso_not_tcp,
3891 	    "Aborted transmit of TSO buffer with non TCP protocol");
3892 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "tx_defragged",
3893 	    CTLFLAG_RD, &stats->tx_defragged,
3894 	    "Transmit mbufs defragged");
3895 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "tx_defrag_failed",
3896 	    CTLFLAG_RD, &stats->tx_defrag_failed,
3897 	    "Aborted transmit of buffer because defrag failed");
3898 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "tx_csum_offloaded",
3899 	    CTLFLAG_RD, &stats->tx_csum_offloaded,
3900 	    "Offloaded checksum of transmitted buffer");
3901 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "tx_tso_offloaded",
3902 	    CTLFLAG_RD, &stats->tx_tso_offloaded,
3903 	    "Segmentation offload of transmitted buffer");
3904 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "tx_task_rescheduled",
3905 	    CTLFLAG_RD, &stats->tx_task_rescheduled,
3906 	    "Times the transmit interrupt task rescheduled itself");
3907 }
3908 
3909 static void
3910 vtnet_setup_sysctl(struct vtnet_softc *sc)
3911 {
3912 	device_t dev;
3913 	struct sysctl_ctx_list *ctx;
3914 	struct sysctl_oid *tree;
3915 	struct sysctl_oid_list *child;
3916 
3917 	dev = sc->vtnet_dev;
3918 	ctx = device_get_sysctl_ctx(dev);
3919 	tree = device_get_sysctl_tree(dev);
3920 	child = SYSCTL_CHILDREN(tree);
3921 
3922 	SYSCTL_ADD_INT(ctx, child, OID_AUTO, "max_vq_pairs",
3923 	    CTLFLAG_RD, &sc->vtnet_max_vq_pairs, 0,
3924 	    "Maximum number of supported virtqueue pairs");
3925 	SYSCTL_ADD_INT(ctx, child, OID_AUTO, "requested_vq_pairs",
3926 	    CTLFLAG_RD, &sc->vtnet_requested_vq_pairs, 0,
3927 	    "Requested number of virtqueue pairs");
3928 	SYSCTL_ADD_INT(ctx, child, OID_AUTO, "act_vq_pairs",
3929 	    CTLFLAG_RD, &sc->vtnet_act_vq_pairs, 0,
3930 	    "Number of active virtqueue pairs");
3931 
3932 	vtnet_setup_stat_sysctl(ctx, child, sc);
3933 }
3934 
3935 static int
3936 vtnet_rxq_enable_intr(struct vtnet_rxq *rxq)
3937 {
3938 
3939 	return (virtqueue_enable_intr(rxq->vtnrx_vq));
3940 }
3941 
3942 static void
3943 vtnet_rxq_disable_intr(struct vtnet_rxq *rxq)
3944 {
3945 
3946 	virtqueue_disable_intr(rxq->vtnrx_vq);
3947 }
3948 
3949 static int
3950 vtnet_txq_enable_intr(struct vtnet_txq *txq)
3951 {
3952 	struct virtqueue *vq;
3953 
3954 	vq = txq->vtntx_vq;
3955 
3956 	if (vtnet_txq_below_threshold(txq) != 0)
3957 		return (virtqueue_postpone_intr(vq, VQ_POSTPONE_LONG));
3958 
3959 	/*
3960 	 * The free count is above our threshold. Keep the Tx interrupt
3961 	 * disabled until the queue is fuller.
3962 	 */
3963 	return (0);
3964 }
3965 
3966 static void
3967 vtnet_txq_disable_intr(struct vtnet_txq *txq)
3968 {
3969 
3970 	virtqueue_disable_intr(txq->vtntx_vq);
3971 }
3972 
3973 static void
3974 vtnet_enable_rx_interrupts(struct vtnet_softc *sc)
3975 {
3976 	int i;
3977 
3978 	for (i = 0; i < sc->vtnet_act_vq_pairs; i++)
3979 		vtnet_rxq_enable_intr(&sc->vtnet_rxqs[i]);
3980 }
3981 
3982 static void
3983 vtnet_enable_tx_interrupts(struct vtnet_softc *sc)
3984 {
3985 	int i;
3986 
3987 	for (i = 0; i < sc->vtnet_act_vq_pairs; i++)
3988 		vtnet_txq_enable_intr(&sc->vtnet_txqs[i]);
3989 }
3990 
3991 static void
3992 vtnet_enable_interrupts(struct vtnet_softc *sc)
3993 {
3994 
3995 	vtnet_enable_rx_interrupts(sc);
3996 	vtnet_enable_tx_interrupts(sc);
3997 }
3998 
3999 static void
4000 vtnet_disable_rx_interrupts(struct vtnet_softc *sc)
4001 {
4002 	int i;
4003 
4004 	for (i = 0; i < sc->vtnet_act_vq_pairs; i++)
4005 		vtnet_rxq_disable_intr(&sc->vtnet_rxqs[i]);
4006 }
4007 
4008 static void
4009 vtnet_disable_tx_interrupts(struct vtnet_softc *sc)
4010 {
4011 	int i;
4012 
4013 	for (i = 0; i < sc->vtnet_act_vq_pairs; i++)
4014 		vtnet_txq_disable_intr(&sc->vtnet_txqs[i]);
4015 }
4016 
4017 static void
4018 vtnet_disable_interrupts(struct vtnet_softc *sc)
4019 {
4020 
4021 	vtnet_disable_rx_interrupts(sc);
4022 	vtnet_disable_tx_interrupts(sc);
4023 }
4024 
4025 static int
4026 vtnet_tunable_int(struct vtnet_softc *sc, const char *knob, int def)
4027 {
4028 	char path[64];
4029 
4030 	snprintf(path, sizeof(path),
4031 	    "hw.vtnet.%d.%s", device_get_unit(sc->vtnet_dev), knob);
4032 	TUNABLE_INT_FETCH(path, &def);
4033 
4034 	return (def);
4035 }
4036 
4037 #ifdef DEBUGNET
4038 static void
4039 vtnet_debugnet_init(struct ifnet *ifp, int *nrxr, int *ncl, int *clsize)
4040 {
4041 	struct vtnet_softc *sc;
4042 
4043 	sc = if_getsoftc(ifp);
4044 
4045 	VTNET_CORE_LOCK(sc);
4046 	*nrxr = sc->vtnet_max_vq_pairs;
4047 	*ncl = DEBUGNET_MAX_IN_FLIGHT;
4048 	*clsize = sc->vtnet_rx_clsize;
4049 	VTNET_CORE_UNLOCK(sc);
4050 }
4051 
4052 static void
4053 vtnet_debugnet_event(struct ifnet *ifp __unused, enum debugnet_ev event __unused)
4054 {
4055 }
4056 
4057 static int
4058 vtnet_debugnet_transmit(struct ifnet *ifp, struct mbuf *m)
4059 {
4060 	struct vtnet_softc *sc;
4061 	struct vtnet_txq *txq;
4062 	int error;
4063 
4064 	sc = if_getsoftc(ifp);
4065 	if ((if_getdrvflags(ifp) & (IFF_DRV_RUNNING | IFF_DRV_OACTIVE)) !=
4066 	    IFF_DRV_RUNNING)
4067 		return (EBUSY);
4068 
4069 	txq = &sc->vtnet_txqs[0];
4070 	error = vtnet_txq_encap(txq, &m, M_NOWAIT | M_USE_RESERVE);
4071 	if (error == 0)
4072 		(void)vtnet_txq_notify(txq);
4073 	return (error);
4074 }
4075 
4076 static int
4077 vtnet_debugnet_poll(struct ifnet *ifp, int count)
4078 {
4079 	struct vtnet_softc *sc;
4080 	int i;
4081 
4082 	sc = if_getsoftc(ifp);
4083 	if ((if_getdrvflags(ifp) & (IFF_DRV_RUNNING | IFF_DRV_OACTIVE)) !=
4084 	    IFF_DRV_RUNNING)
4085 		return (EBUSY);
4086 
4087 	(void)vtnet_txq_eof(&sc->vtnet_txqs[0]);
4088 	for (i = 0; i < sc->vtnet_max_vq_pairs; i++)
4089 		(void)vtnet_rxq_eof(&sc->vtnet_rxqs[i]);
4090 	return (0);
4091 }
4092 #endif /* DEBUGNET */
4093