xref: /dragonfly/sys/dev/virtual/virtio/net/if_vtnet.c (revision 099c4d8e)
1 /*-
2  * Copyright (c) 2011, Bryan Venteicher <bryanv@FreeBSD.org>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice unmodified, this list of conditions, and the following
10  *    disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 /* Driver for VirtIO network devices. */
28 
29 #include <sys/cdefs.h>
30 
31 #include <sys/param.h>
32 #include <sys/systm.h>
33 #include <sys/kernel.h>
34 #include <sys/sockio.h>
35 #include <sys/mbuf.h>
36 #include <sys/malloc.h>
37 #include <sys/module.h>
38 #include <sys/socket.h>
39 #include <sys/sysctl.h>
40 #include <sys/taskqueue.h>
41 #include <sys/random.h>
42 #include <sys/sglist.h>
43 #include <sys/serialize.h>
44 #include <sys/bus.h>
45 #include <sys/rman.h>
46 
47 #include <machine/limits.h>
48 
49 #include <net/ethernet.h>
50 #include <net/if.h>
51 #include <net/if_arp.h>
52 #include <net/if_dl.h>
53 #include <net/if_types.h>
54 #include <net/if_media.h>
55 #include <net/vlan/if_vlan_var.h>
56 #include <net/vlan/if_vlan_ether.h>
57 #include <net/ifq_var.h>
58 
59 #include <net/bpf.h>
60 
61 #include <netinet/in_systm.h>
62 #include <netinet/in.h>
63 #include <netinet/ip.h>
64 #include <netinet/ip6.h>
65 #include <netinet/udp.h>
66 #include <netinet/tcp.h>
67 
68 #include <dev/virtual/virtio/virtio/virtio.h>
69 #include <dev/virtual/virtio/virtio/virtqueue.h>
70 #include <dev/virtual/virtio/net/virtio_net.h>
71 #include <dev/virtual/virtio/net/if_vtnetvar.h>
72 
73 MALLOC_DEFINE(M_VTNET, "VTNET_TX", "Outgoing VTNET TX frame header");
74 
75 static int	vtnet_probe(device_t);
76 static int	vtnet_attach(device_t);
77 static int	vtnet_detach(device_t);
78 static int	vtnet_suspend(device_t);
79 static int	vtnet_resume(device_t);
80 static int	vtnet_shutdown(device_t);
81 
82 static void	vtnet_negotiate_features(struct vtnet_softc *);
83 static int	vtnet_alloc_intrs(struct vtnet_softc *);
84 static int	vtnet_alloc_virtqueues(struct vtnet_softc *);
85 static void	vtnet_get_hwaddr(struct vtnet_softc *);
86 static void	vtnet_set_hwaddr(struct vtnet_softc *);
87 static int	vtnet_is_link_up(struct vtnet_softc *);
88 static void	vtnet_update_link_status(struct vtnet_softc *);
89 #if 0
90 static void	vtnet_watchdog(struct vtnet_softc *);
91 #endif
92 static void	vtnet_config_change_task(void *, int);
93 static int	vtnet_setup_interface(struct vtnet_softc *);
94 static int	vtnet_change_mtu(struct vtnet_softc *, int);
95 static int	vtnet_ioctl(struct ifnet *, u_long, caddr_t, struct ucred *);
96 
97 static int	vtnet_init_rx_vq(struct vtnet_softc *);
98 static void	vtnet_free_rx_mbufs(struct vtnet_softc *);
99 static void	vtnet_free_tx_mbufs(struct vtnet_softc *);
100 static void	vtnet_free_ctrl_vq(struct vtnet_softc *);
101 
102 static struct mbuf * vtnet_alloc_rxbuf(struct vtnet_softc *, int,
103 		    struct mbuf **);
104 static int	vtnet_replace_rxbuf(struct vtnet_softc *,
105 		    struct mbuf *, int);
106 static int	vtnet_newbuf(struct vtnet_softc *);
107 static void	vtnet_discard_merged_rxbuf(struct vtnet_softc *, int);
108 static void	vtnet_discard_rxbuf(struct vtnet_softc *, struct mbuf *);
109 static int	vtnet_enqueue_rxbuf(struct vtnet_softc *, struct mbuf *);
110 static void	vtnet_vlan_tag_remove(struct mbuf *);
111 static int	vtnet_rx_csum(struct vtnet_softc *, struct mbuf *,
112 		    struct virtio_net_hdr *);
113 static int	vtnet_rxeof_merged(struct vtnet_softc *, struct mbuf *, int);
114 static int	vtnet_rxeof(struct vtnet_softc *, int, int *);
115 static void	vtnet_rx_intr_task(void *);
116 static void	vtnet_rx_vq_intr(void *);
117 
118 static void	vtnet_enqueue_txhdr(struct vtnet_softc *,
119 		    struct vtnet_tx_header *);
120 static void	vtnet_txeof(struct vtnet_softc *);
121 static struct mbuf * vtnet_tx_offload(struct vtnet_softc *, struct mbuf *,
122 		    struct virtio_net_hdr *);
123 static int	vtnet_enqueue_txbuf(struct vtnet_softc *, struct mbuf **,
124 		    struct vtnet_tx_header *);
125 static int	vtnet_encap(struct vtnet_softc *, struct mbuf **);
126 static void	vtnet_start_locked(struct ifnet *, struct ifaltq_subque *);
127 static void	vtnet_start(struct ifnet *, struct ifaltq_subque *);
128 static void	vtnet_tick(void *);
129 static void	vtnet_tx_intr_task(void *);
130 static void	vtnet_tx_vq_intr(void *);
131 
132 static void	vtnet_config_intr(void *);
133 
134 static void	vtnet_stop(struct vtnet_softc *);
135 static int	vtnet_virtio_reinit(struct vtnet_softc *);
136 static void	vtnet_init_locked(struct vtnet_softc *);
137 static void	vtnet_init(void *);
138 
139 static void	vtnet_exec_ctrl_cmd(struct vtnet_softc *, void *,
140 		    struct sglist *, int, int);
141 
142 static int	vtnet_ctrl_mac_cmd(struct vtnet_softc *, uint8_t *);
143 static int	vtnet_ctrl_rx_cmd(struct vtnet_softc *, int, int);
144 static int	vtnet_set_promisc(struct vtnet_softc *, int);
145 static int	vtnet_set_allmulti(struct vtnet_softc *, int);
146 static void	vtnet_rx_filter(struct vtnet_softc *sc);
147 static void	vtnet_rx_filter_mac(struct vtnet_softc *);
148 
149 static int	vtnet_exec_vlan_filter(struct vtnet_softc *, int, uint16_t);
150 static void	vtnet_rx_filter_vlan(struct vtnet_softc *);
151 static void	vtnet_update_vlan_filter(struct vtnet_softc *, int, uint16_t);
152 static void	vtnet_register_vlan(void *, struct ifnet *, uint16_t);
153 static void	vtnet_unregister_vlan(void *, struct ifnet *, uint16_t);
154 
155 static int	vtnet_ifmedia_upd(struct ifnet *);
156 static void	vtnet_ifmedia_sts(struct ifnet *, struct ifmediareq *);
157 
158 static void	vtnet_add_statistics(struct vtnet_softc *);
159 
160 static int	vtnet_enable_rx_intr(struct vtnet_softc *);
161 static int	vtnet_enable_tx_intr(struct vtnet_softc *);
162 static void	vtnet_disable_rx_intr(struct vtnet_softc *);
163 static void	vtnet_disable_tx_intr(struct vtnet_softc *);
164 
165 /* Tunables. */
166 static int vtnet_csum_disable = 0;
167 TUNABLE_INT("hw.vtnet.csum_disable", &vtnet_csum_disable);
168 static int vtnet_tso_disable = 1;
169 TUNABLE_INT("hw.vtnet.tso_disable", &vtnet_tso_disable);
170 static int vtnet_lro_disable = 0;
171 TUNABLE_INT("hw.vtnet.lro_disable", &vtnet_lro_disable);
172 
173 /*
174  * Reducing the number of transmit completed interrupts can
175  * improve performance. To do so, the define below keeps the
176  * Tx vq interrupt disabled and adds calls to vtnet_txeof()
177  * in the start and watchdog paths. The price to pay for this
178  * is the m_free'ing of transmitted mbufs may be delayed until
179  * the watchdog fires.
180  */
181 #define VTNET_TX_INTR_MODERATION
182 
183 static struct virtio_feature_desc vtnet_feature_desc[] = {
184 	{ VIRTIO_NET_F_CSUM,		"TxChecksum"	},
185 	{ VIRTIO_NET_F_GUEST_CSUM,	"RxChecksum"	},
186 	{ VIRTIO_NET_F_CTRL_GUEST_OFFLOADS, "DynOffload"	},
187 	{ VIRTIO_NET_F_MAC,		"MacAddress"	},
188 	{ VIRTIO_NET_F_GSO,		"TxAllGSO"	},
189 	{ VIRTIO_NET_F_GUEST_TSO4,	"RxTSOv4"	},
190 	{ VIRTIO_NET_F_GUEST_TSO6,	"RxTSOv6"	},
191 	{ VIRTIO_NET_F_GUEST_ECN,	"RxECN"		},
192 	{ VIRTIO_NET_F_GUEST_UFO,	"RxUFO"		},
193 	{ VIRTIO_NET_F_HOST_TSO4,	"TxTSOv4"	},
194 	{ VIRTIO_NET_F_HOST_TSO6,	"TxTSOv6"	},
195 	{ VIRTIO_NET_F_HOST_ECN,	"TxTSOECN"	},
196 	{ VIRTIO_NET_F_HOST_UFO,	"TxUFO"		},
197 	{ VIRTIO_NET_F_MRG_RXBUF,	"MrgRxBuf"	},
198 	{ VIRTIO_NET_F_STATUS,		"Status"	},
199 	{ VIRTIO_NET_F_CTRL_VQ,		"ControlVq"	},
200 	{ VIRTIO_NET_F_CTRL_RX,		"RxMode"	},
201 	{ VIRTIO_NET_F_CTRL_VLAN,	"VLanFilter"	},
202 	{ VIRTIO_NET_F_CTRL_RX_EXTRA,	"RxModeExtra"	},
203 	{ VIRTIO_NET_F_GUEST_ANNOUNCE,	"GuestAnnounce"	},
204 	{ VIRTIO_NET_F_MQ,		"RFS"		},
205 	{ VIRTIO_NET_F_CTRL_MAC_ADDR,	"SetMacAddress"	},
206 	{ 0, NULL }
207 };
208 
209 static device_method_t vtnet_methods[] = {
210 	/* Device methods. */
211 	DEVMETHOD(device_probe,		vtnet_probe),
212 	DEVMETHOD(device_attach,	vtnet_attach),
213 	DEVMETHOD(device_detach,	vtnet_detach),
214 	DEVMETHOD(device_suspend,	vtnet_suspend),
215 	DEVMETHOD(device_resume,	vtnet_resume),
216 	DEVMETHOD(device_shutdown,	vtnet_shutdown),
217 
218 	DEVMETHOD_END
219 };
220 
221 static driver_t vtnet_driver = {
222 	"vtnet",
223 	vtnet_methods,
224 	sizeof(struct vtnet_softc)
225 };
226 
227 static devclass_t vtnet_devclass;
228 
229 DRIVER_MODULE(vtnet, virtio_pci, vtnet_driver, vtnet_devclass, NULL, NULL);
230 MODULE_VERSION(vtnet, 1);
231 MODULE_DEPEND(vtnet, virtio, 1, 1, 1);
232 
233 static int
234 vtnet_probe(device_t dev)
235 {
236 	if (virtio_get_device_type(dev) != VIRTIO_ID_NETWORK)
237 		return (ENXIO);
238 
239 	device_set_desc(dev, "VirtIO Networking Adapter");
240 
241 	return (BUS_PROBE_DEFAULT);
242 }
243 
244 struct irqmap {
245 	int irq;
246 	driver_intr_t *handler;
247 };
248 
249 static int
250 vtnet_attach(device_t dev)
251 {
252 	struct vtnet_softc *sc;
253 	int i, error;
254 
255 	sc = device_get_softc(dev);
256 	sc->vtnet_dev = dev;
257 
258 	lwkt_serialize_init(&sc->vtnet_slz);
259 	callout_init(&sc->vtnet_tick_ch);
260 
261 	ifmedia_init(&sc->vtnet_media, IFM_IMASK, vtnet_ifmedia_upd,
262 		     vtnet_ifmedia_sts);
263 	ifmedia_add(&sc->vtnet_media, VTNET_MEDIATYPE, 0, NULL);
264 	ifmedia_set(&sc->vtnet_media, VTNET_MEDIATYPE);
265 
266 	vtnet_add_statistics(sc);
267 	SLIST_INIT(&sc->vtnet_txhdr_free);
268 
269 	/* Register our feature descriptions. */
270 	virtio_set_feature_desc(dev, vtnet_feature_desc);
271 	vtnet_negotiate_features(sc);
272 
273 	if (virtio_with_feature(dev, VIRTIO_RING_F_INDIRECT_DESC))
274 		sc->vtnet_flags |= VTNET_FLAG_INDIRECT;
275 
276 	if (virtio_with_feature(dev, VIRTIO_NET_F_MAC)) {
277 		/* This feature should always be negotiated. */
278 		sc->vtnet_flags |= VTNET_FLAG_MAC;
279 	}
280 
281 	if (virtio_with_feature(dev, VIRTIO_NET_F_MRG_RXBUF)) {
282 		sc->vtnet_flags |= VTNET_FLAG_MRG_RXBUFS;
283 		sc->vtnet_hdr_size = sizeof(struct virtio_net_hdr_mrg_rxbuf);
284 	} else {
285 		sc->vtnet_hdr_size = sizeof(struct virtio_net_hdr);
286 	}
287 
288 	sc->vtnet_rx_mbuf_size = MCLBYTES;
289 	sc->vtnet_rx_mbuf_count = VTNET_NEEDED_RX_MBUFS(sc);
290 
291 	if (virtio_with_feature(dev, VIRTIO_NET_F_CTRL_VQ)) {
292 		sc->vtnet_flags |= VTNET_FLAG_CTRL_VQ;
293 
294 		if (virtio_with_feature(dev, VIRTIO_NET_F_CTRL_RX))
295 			sc->vtnet_flags |= VTNET_FLAG_CTRL_RX;
296 		if (virtio_with_feature(dev, VIRTIO_NET_F_CTRL_VLAN))
297 			sc->vtnet_flags |= VTNET_FLAG_VLAN_FILTER;
298 		if (virtio_with_feature(dev, VIRTIO_NET_F_CTRL_MAC_ADDR) &&
299 		    virtio_with_feature(dev, VIRTIO_NET_F_CTRL_RX))
300 			sc->vtnet_flags |= VTNET_FLAG_CTRL_MAC;
301 	}
302 
303 	error = vtnet_alloc_intrs(sc);
304 	if (error) {
305 		device_printf(dev, "cannot allocate interrupts\n");
306 		goto fail;
307 	}
308 
309 	error = vtnet_alloc_virtqueues(sc);
310 	if (error) {
311 		device_printf(dev, "cannot allocate virtqueues\n");
312 		goto fail;
313 	}
314 
315 	/* XXX Separate function */
316 	struct irqmap info[2];
317 
318 	/* Possible "Virtqueue <-> IRQ" configurations */
319 	switch (sc->vtnet_nintr) {
320 	case 1:
321 		info[0] = (struct irqmap){0, vtnet_rx_vq_intr};
322 		info[1] = (struct irqmap){0, vtnet_tx_vq_intr};
323 		break;
324 	case 2:
325 		if (virtio_with_feature(dev, VIRTIO_NET_F_STATUS)) {
326 			info[0] = (struct irqmap){1, vtnet_rx_vq_intr};
327 		} else {
328 			info[0] = (struct irqmap){0, vtnet_rx_vq_intr};
329 		}
330 		info[1] = (struct irqmap){1, vtnet_tx_vq_intr};
331 		break;
332 	case 3:
333 		info[0] = (struct irqmap){1, vtnet_rx_vq_intr};
334 		info[1] = (struct irqmap){2, vtnet_tx_vq_intr};
335 		break;
336 	default:
337 		device_printf(dev, "Invalid interrupt vector count: %d\n",
338 		    sc->vtnet_nintr);
339 		goto fail;
340 	}
341 	for (i = 0; i < 2; i++) {
342 		error = virtio_bind_intr(dev, info[i].irq, i,
343 		    info[i].handler, sc);
344 		if (error) {
345 			device_printf(dev, "cannot bind virtqueue IRQs\n");
346 			goto fail;
347 		}
348 	}
349 	if (virtio_with_feature(dev, VIRTIO_NET_F_STATUS)) {
350 		error = virtio_bind_intr(dev, 0, -1, vtnet_config_intr, sc);
351 		if (error) {
352 			device_printf(dev, "cannot bind config_change IRQ\n");
353 			goto fail;
354 		}
355 	}
356 
357 	/* Read (or generate) the MAC address for the adapter. */
358 	vtnet_get_hwaddr(sc);
359 
360 	error = vtnet_setup_interface(sc);
361 	if (error) {
362 		device_printf(dev, "cannot setup interface\n");
363 		goto fail;
364 	}
365 
366 	TASK_INIT(&sc->vtnet_cfgchg_task, 0, vtnet_config_change_task, sc);
367 
368 	for (i = 0; i < sc->vtnet_nintr; i++) {
369 		error = virtio_setup_intr(dev, i, &sc->vtnet_slz);
370 		if (error) {
371 			device_printf(dev, "cannot setup virtqueue "
372 			    "interrupts\n");
373 			ether_ifdetach(sc->vtnet_ifp);
374 			goto fail;
375 		}
376 	}
377 
378 	if ((sc->vtnet_flags & VTNET_FLAG_MAC) == 0) {
379 		lwkt_serialize_enter(&sc->vtnet_slz);
380 		vtnet_set_hwaddr(sc);
381 		lwkt_serialize_exit(&sc->vtnet_slz);
382 	}
383 
384 	/*
385 	 * Device defaults to promiscuous mode for backwards
386 	 * compatibility. Turn it off if possible.
387 	 */
388 	if (sc->vtnet_flags & VTNET_FLAG_CTRL_RX) {
389 		lwkt_serialize_enter(&sc->vtnet_slz);
390 		if (vtnet_set_promisc(sc, 0) != 0) {
391 			sc->vtnet_ifp->if_flags |= IFF_PROMISC;
392 			device_printf(dev,
393 			    "cannot disable promiscuous mode\n");
394 		}
395 		lwkt_serialize_exit(&sc->vtnet_slz);
396 	} else
397 		sc->vtnet_ifp->if_flags |= IFF_PROMISC;
398 
399 fail:
400 	if (error)
401 		vtnet_detach(dev);
402 
403 	return (error);
404 }
405 
406 static int
407 vtnet_detach(device_t dev)
408 {
409 	struct vtnet_softc *sc;
410 	struct ifnet *ifp;
411 	int i;
412 
413 	sc = device_get_softc(dev);
414 	ifp = sc->vtnet_ifp;
415 
416 	for (i = 0; i < sc->vtnet_nintr; i++)
417 		virtio_teardown_intr(dev, i);
418 
419 	if (device_is_attached(dev)) {
420 		lwkt_serialize_enter(&sc->vtnet_slz);
421 		vtnet_stop(sc);
422 		lwkt_serialize_exit(&sc->vtnet_slz);
423 
424 		callout_stop(&sc->vtnet_tick_ch);
425 		taskqueue_drain(taskqueue_swi, &sc->vtnet_cfgchg_task);
426 
427 		ether_ifdetach(ifp);
428 	}
429 
430 	if (sc->vtnet_vlan_attach != NULL) {
431 		EVENTHANDLER_DEREGISTER(vlan_config, sc->vtnet_vlan_attach);
432 		sc->vtnet_vlan_attach = NULL;
433 	}
434 	if (sc->vtnet_vlan_detach != NULL) {
435 		EVENTHANDLER_DEREGISTER(vlan_unconfig, sc->vtnet_vlan_detach);
436 		sc->vtnet_vlan_detach = NULL;
437 	}
438 
439 	if (ifp) {
440 		if_free(ifp);
441 		sc->vtnet_ifp = NULL;
442 	}
443 
444 	if (sc->vtnet_rx_vq != NULL)
445 		vtnet_free_rx_mbufs(sc);
446 	if (sc->vtnet_tx_vq != NULL)
447 		vtnet_free_tx_mbufs(sc);
448 	if (sc->vtnet_ctrl_vq != NULL)
449 		vtnet_free_ctrl_vq(sc);
450 
451 	if (sc->vtnet_txhdrarea != NULL) {
452 		contigfree(sc->vtnet_txhdrarea,
453 		    sc->vtnet_txhdrcount * sizeof(struct vtnet_tx_header),
454 		    M_VTNET);
455 		sc->vtnet_txhdrarea = NULL;
456 	}
457 	SLIST_INIT(&sc->vtnet_txhdr_free);
458 	if (sc->vtnet_macfilter != NULL) {
459 		contigfree(sc->vtnet_macfilter,
460 		    sizeof(struct vtnet_mac_filter), M_DEVBUF);
461 		sc->vtnet_macfilter = NULL;
462 	}
463 
464 	ifmedia_removeall(&sc->vtnet_media);
465 
466 	return (0);
467 }
468 
469 static int
470 vtnet_suspend(device_t dev)
471 {
472 	struct vtnet_softc *sc;
473 
474 	sc = device_get_softc(dev);
475 
476 	lwkt_serialize_enter(&sc->vtnet_slz);
477 	vtnet_stop(sc);
478 	sc->vtnet_flags |= VTNET_FLAG_SUSPENDED;
479 	lwkt_serialize_exit(&sc->vtnet_slz);
480 
481 	return (0);
482 }
483 
484 static int
485 vtnet_resume(device_t dev)
486 {
487 	struct vtnet_softc *sc;
488 	struct ifnet *ifp;
489 
490 	sc = device_get_softc(dev);
491 	ifp = sc->vtnet_ifp;
492 
493 	lwkt_serialize_enter(&sc->vtnet_slz);
494 	if (ifp->if_flags & IFF_UP)
495 		vtnet_init_locked(sc);
496 	sc->vtnet_flags &= ~VTNET_FLAG_SUSPENDED;
497 	lwkt_serialize_exit(&sc->vtnet_slz);
498 
499 	return (0);
500 }
501 
502 static int
503 vtnet_shutdown(device_t dev)
504 {
505 
506 	/*
507 	 * Suspend already does all of what we need to
508 	 * do here; we just never expect to be resumed.
509 	 */
510 	return (vtnet_suspend(dev));
511 }
512 
513 static void
514 vtnet_negotiate_features(struct vtnet_softc *sc)
515 {
516 	device_t dev;
517 	uint64_t mask, features;
518 
519 	dev = sc->vtnet_dev;
520 	mask = 0;
521 
522 	if (vtnet_csum_disable)
523 		mask |= VIRTIO_NET_F_CSUM | VIRTIO_NET_F_GUEST_CSUM;
524 
525 	/*
526 	 * XXX DragonFly doesn't support receive checksum offload for ipv6 yet,
527 	 *     hence always disable the virtio feature for now.
528 	 * XXX We need to support the DynOffload feature, in order to
529 	 *     dynamically enable/disable this feature.
530 	 */
531 	mask |= VIRTIO_NET_F_GUEST_CSUM;
532 
533 	/*
534 	 * TSO is only available when the tx checksum offload feature is also
535 	 * negotiated.
536 	 */
537 	if (vtnet_csum_disable || vtnet_tso_disable)
538 		mask |= VIRTIO_NET_F_HOST_TSO4 | VIRTIO_NET_F_HOST_TSO6 |
539 		    VIRTIO_NET_F_HOST_ECN;
540 
541 	if (vtnet_lro_disable)
542 		mask |= VTNET_LRO_FEATURES;
543 
544 	features = VTNET_FEATURES & ~mask;
545 	features |= VIRTIO_F_NOTIFY_ON_EMPTY;
546 	features |= VIRTIO_F_ANY_LAYOUT;
547 	sc->vtnet_features = virtio_negotiate_features(dev, features);
548 
549 	if (virtio_with_feature(dev, VTNET_LRO_FEATURES) &&
550 	    virtio_with_feature(dev, VIRTIO_NET_F_MRG_RXBUF) == 0) {
551 		/*
552 		 * LRO without mergeable buffers requires special care. This
553 		 * is not ideal because every receive buffer must be large
554 		 * enough to hold the maximum TCP packet, the Ethernet header,
555 		 * and the header. This requires up to 34 descriptors with
556 		 * MCLBYTES clusters. If we do not have indirect descriptors,
557 		 * LRO is disabled since the virtqueue will not contain very
558 		 * many receive buffers.
559 		 */
560 		if (!virtio_with_feature(dev, VIRTIO_RING_F_INDIRECT_DESC)) {
561 			device_printf(dev,
562 			    "LRO disabled due to both mergeable buffers and "
563 			    "indirect descriptors not negotiated\n");
564 
565 			features &= ~VTNET_LRO_FEATURES;
566 			sc->vtnet_features =
567 			    virtio_negotiate_features(dev, features);
568 		} else
569 			sc->vtnet_flags |= VTNET_FLAG_LRO_NOMRG;
570 	}
571 }
572 
573 static int
574 vtnet_alloc_intrs(struct vtnet_softc *sc)
575 {
576 	int cnt, error;
577 	int intrcount = virtio_intr_count(sc->vtnet_dev);
578 	int i;
579 	int use_config;
580 
581 	if (virtio_with_feature(sc->vtnet_dev, VIRTIO_NET_F_STATUS)) {
582 		use_config = 1;
583 		/* We can use a maximum of 3 interrupt vectors. */
584 		intrcount = imin(intrcount, 3);
585 	} else {
586 		/* We can use a maximum of 2 interrupt vectors. */
587 		intrcount = imin(intrcount, 2);
588 	}
589 
590 	if (intrcount < 1)
591 		return (ENXIO);
592 
593 	/*
594 	 * XXX We should explicitly set the cpus for the rx/tx threads, to
595 	 *     only use cpus, where the network stack is running.
596 	 */
597 	for (i = 0; i < intrcount; i++)
598 		sc->vtnet_cpus[i] = -1;
599 
600 	cnt = intrcount;
601         error = virtio_intr_alloc(sc->vtnet_dev, &cnt, use_config,
602 	    sc->vtnet_cpus);
603         if (error != 0) {
604 		virtio_intr_release(sc->vtnet_dev);
605                 return (error);
606 	}
607 	sc->vtnet_nintr = cnt;
608 
609         return (0);
610 }
611 
612 static int
613 vtnet_alloc_virtqueues(struct vtnet_softc *sc)
614 {
615 	device_t dev;
616 	struct vq_alloc_info vq_info[3];
617 	int nvqs;
618 
619 	dev = sc->vtnet_dev;
620 	nvqs = 2;
621 
622 	/*
623 	 * Indirect descriptors are not needed for the Rx
624 	 * virtqueue when mergeable buffers are negotiated.
625 	 * The header is placed inline with the data, not
626 	 * in a separate descriptor, and mbuf clusters are
627 	 * always physically contiguous.
628 	 */
629 	if ((sc->vtnet_flags & VTNET_FLAG_MRG_RXBUFS) == 0) {
630 		sc->vtnet_rx_nsegs = (sc->vtnet_flags & VTNET_FLAG_LRO_NOMRG) ?
631 		    VTNET_MAX_RX_SEGS : VTNET_MIN_RX_SEGS;
632 	} else
633 		sc->vtnet_rx_nsegs = VTNET_MRG_RX_SEGS;
634 
635 	if (virtio_with_feature(dev, VIRTIO_NET_F_HOST_TSO4) ||
636             virtio_with_feature(dev, VIRTIO_NET_F_HOST_TSO6))
637 		sc->vtnet_tx_nsegs = VTNET_MAX_TX_SEGS;
638 	else
639 		sc->vtnet_tx_nsegs = VTNET_MIN_TX_SEGS;
640 
641 	VQ_ALLOC_INFO_INIT(&vq_info[0], sc->vtnet_rx_nsegs, &sc->vtnet_rx_vq,
642 	    "%s receive", device_get_nameunit(dev));
643 
644 	VQ_ALLOC_INFO_INIT(&vq_info[1], sc->vtnet_tx_nsegs, &sc->vtnet_tx_vq,
645 	    "%s transmit", device_get_nameunit(dev));
646 
647 	if (sc->vtnet_flags & VTNET_FLAG_CTRL_VQ) {
648 		nvqs++;
649 
650 		VQ_ALLOC_INFO_INIT(&vq_info[2], 0, &sc->vtnet_ctrl_vq,
651 		    "%s control", device_get_nameunit(dev));
652 	}
653 
654 	return (virtio_alloc_virtqueues(dev, nvqs, vq_info));
655 }
656 
657 static int
658 vtnet_setup_interface(struct vtnet_softc *sc)
659 {
660 	device_t dev;
661 	struct ifnet *ifp;
662 	int i;
663 
664 	dev = sc->vtnet_dev;
665 
666 	ifp = sc->vtnet_ifp = if_alloc(IFT_ETHER);
667 	if (ifp == NULL) {
668 		device_printf(dev, "cannot allocate ifnet structure\n");
669 		return (ENOSPC);
670 	}
671 
672 	ifp->if_softc = sc;
673 	if_initname(ifp, device_get_name(dev), device_get_unit(dev));
674 	ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
675 	ifp->if_init = vtnet_init;
676 	ifp->if_start = vtnet_start;
677 	ifp->if_ioctl = vtnet_ioctl;
678 
679 	sc->vtnet_rx_process_limit = virtqueue_size(sc->vtnet_rx_vq);
680 	sc->vtnet_tx_size = virtqueue_size(sc->vtnet_tx_vq);
681 	if (sc->vtnet_flags & VTNET_FLAG_INDIRECT)
682 		sc->vtnet_txhdrcount = sc->vtnet_tx_size;
683 	else
684 		sc->vtnet_txhdrcount = (sc->vtnet_tx_size / 2) + 1;
685 	sc->vtnet_txhdrarea = contigmalloc(
686 	    sc->vtnet_txhdrcount * sizeof(struct vtnet_tx_header),
687 	    M_VTNET, M_WAITOK, 0, BUS_SPACE_MAXADDR, 4, 0);
688 	if (sc->vtnet_txhdrarea == NULL) {
689 		device_printf(dev, "cannot contigmalloc the tx headers\n");
690 		return (ENOMEM);
691 	}
692 	for (i = 0; i < sc->vtnet_txhdrcount; i++)
693 		vtnet_enqueue_txhdr(sc, &sc->vtnet_txhdrarea[i]);
694 	sc->vtnet_macfilter = contigmalloc(
695 	    sizeof(struct vtnet_mac_filter),
696 	    M_DEVBUF, M_WAITOK, 0, BUS_SPACE_MAXADDR, 4, 0);
697 	if (sc->vtnet_macfilter == NULL) {
698 		device_printf(dev,
699 		    "cannot contigmalloc the mac filter table\n");
700 		return (ENOMEM);
701 	}
702 	ifq_set_maxlen(&ifp->if_snd, sc->vtnet_tx_size - 1);
703 	ifq_set_ready(&ifp->if_snd);
704 
705 	ether_ifattach(ifp, sc->vtnet_hwaddr, NULL);
706 
707 	/* The Tx IRQ is currently always the last allocated interrupt. */
708 	ifq_set_cpuid(&ifp->if_snd, sc->vtnet_cpus[sc->vtnet_nintr - 1]);
709 
710 	/* Tell the upper layer(s) we support long frames. */
711 	ifp->if_data.ifi_hdrlen = sizeof(struct ether_vlan_header);
712 	ifp->if_capabilities |= IFCAP_JUMBO_MTU | IFCAP_VLAN_MTU;
713 
714 	if (virtio_with_feature(dev, VIRTIO_NET_F_CSUM)) {
715 		ifp->if_capabilities |= IFCAP_TXCSUM;
716 
717 		if (virtio_with_feature(dev, VIRTIO_NET_F_HOST_TSO4))
718 			ifp->if_capabilities |= IFCAP_TSO4;
719 		if (virtio_with_feature(dev, VIRTIO_NET_F_HOST_TSO6))
720 			ifp->if_capabilities |= IFCAP_TSO6;
721 		if (ifp->if_capabilities & IFCAP_TSO)
722 			ifp->if_capabilities |= IFCAP_VLAN_HWTSO;
723 
724 		if (virtio_with_feature(dev, VIRTIO_NET_F_HOST_ECN))
725 			sc->vtnet_flags |= VTNET_FLAG_TSO_ECN;
726 	}
727 
728 	if (virtio_with_feature(dev, VIRTIO_NET_F_GUEST_CSUM))
729 		ifp->if_capabilities |= IFCAP_RXCSUM;
730 
731 #if 0	/* IFCAP_LRO doesn't exist in DragonFly. */
732 	if (virtio_with_feature(dev, VIRTIO_NET_F_GUEST_TSO4) ||
733 	    virtio_with_feature(dev, VIRTIO_NET_F_GUEST_TSO6))
734 		ifp->if_capabilities |= IFCAP_LRO;
735 #endif
736 
737 	if ((ifp->if_capabilities & IFCAP_HWCSUM) == IFCAP_HWCSUM) {
738 		/*
739 		 * VirtIO does not support VLAN tagging, but we can fake
740 		 * it by inserting and removing the 802.1Q header during
741 		 * transmit and receive. We are then able to do checksum
742 		 * offloading of VLAN frames.
743 		 */
744 		ifp->if_capabilities |=
745 			IFCAP_VLAN_HWTAGGING | IFCAP_VLAN_HWCSUM;
746 	}
747 
748 	ifp->if_capenable = ifp->if_capabilities;
749 
750 	/*
751 	 * Capabilities after here are not enabled by default.
752 	 */
753 
754 	if (sc->vtnet_flags & VTNET_FLAG_VLAN_FILTER) {
755 		ifp->if_capabilities |= IFCAP_VLAN_HWFILTER;
756 
757 		sc->vtnet_vlan_attach = EVENTHANDLER_REGISTER(vlan_config,
758 		    vtnet_register_vlan, sc, EVENTHANDLER_PRI_FIRST);
759 		sc->vtnet_vlan_detach = EVENTHANDLER_REGISTER(vlan_unconfig,
760 		    vtnet_unregister_vlan, sc, EVENTHANDLER_PRI_FIRST);
761 	}
762 
763 	return (0);
764 }
765 
766 static void
767 vtnet_set_hwaddr(struct vtnet_softc *sc)
768 {
769 	device_t dev;
770 
771 	dev = sc->vtnet_dev;
772 
773 	if ((sc->vtnet_flags & VTNET_FLAG_CTRL_MAC) &&
774 	    (sc->vtnet_flags & VTNET_FLAG_CTRL_RX)) {
775 		if (vtnet_ctrl_mac_cmd(sc, sc->vtnet_hwaddr) != 0)
776 			device_printf(dev, "unable to set MAC address\n");
777 	} else if (sc->vtnet_flags & VTNET_FLAG_MAC) {
778 		virtio_write_device_config(dev,
779 		    offsetof(struct virtio_net_config, mac),
780 		    sc->vtnet_hwaddr, ETHER_ADDR_LEN);
781 	}
782 }
783 
784 static void
785 vtnet_get_hwaddr(struct vtnet_softc *sc)
786 {
787 	device_t dev;
788 
789 	dev = sc->vtnet_dev;
790 
791 	if ((sc->vtnet_flags & VTNET_FLAG_MAC) == 0) {
792 		/*
793 		 * Generate a random locally administered unicast address.
794 		 *
795 		 * It would be nice to generate the same MAC address across
796 		 * reboots, but it seems all the hosts currently available
797 		 * support the MAC feature, so this isn't too important.
798 		 */
799 		sc->vtnet_hwaddr[0] = 0xB2;
800 		karc4rand(&sc->vtnet_hwaddr[1], ETHER_ADDR_LEN - 1);
801 		return;
802 	}
803 
804 	virtio_read_device_config(dev,
805 	    offsetof(struct virtio_net_config, mac),
806 	    sc->vtnet_hwaddr, ETHER_ADDR_LEN);
807 }
808 
809 static int
810 vtnet_is_link_up(struct vtnet_softc *sc)
811 {
812 	device_t dev;
813 	struct ifnet *ifp;
814 	uint16_t status;
815 
816 	dev = sc->vtnet_dev;
817 	ifp = sc->vtnet_ifp;
818 
819 	ASSERT_SERIALIZED(&sc->vtnet_slz);
820 
821 	if (virtio_with_feature(dev, VIRTIO_NET_F_STATUS)) {
822 		status = virtio_read_dev_config_2(dev,
823 				offsetof(struct virtio_net_config, status));
824 	} else {
825 		status = VIRTIO_NET_S_LINK_UP;
826 	}
827 
828 	return ((status & VIRTIO_NET_S_LINK_UP) != 0);
829 }
830 
831 static void
832 vtnet_update_link_status(struct vtnet_softc *sc)
833 {
834 	device_t dev;
835 	struct ifnet *ifp;
836 	struct ifaltq_subque *ifsq;
837 	int link;
838 
839 	dev = sc->vtnet_dev;
840 	ifp = sc->vtnet_ifp;
841 	ifsq = ifq_get_subq_default(&ifp->if_snd);
842 
843 	link = vtnet_is_link_up(sc);
844 
845 	if (link && ((sc->vtnet_flags & VTNET_FLAG_LINK) == 0)) {
846 		sc->vtnet_flags |= VTNET_FLAG_LINK;
847 		if (bootverbose)
848 			device_printf(dev, "Link is up\n");
849 		ifp->if_link_state = LINK_STATE_UP;
850 		if_link_state_change(ifp);
851 		if (!ifsq_is_empty(ifsq))
852 			vtnet_start_locked(ifp, ifsq);
853 	} else if (!link && (sc->vtnet_flags & VTNET_FLAG_LINK)) {
854 		sc->vtnet_flags &= ~VTNET_FLAG_LINK;
855 		if (bootverbose)
856 			device_printf(dev, "Link is down\n");
857 
858 		ifp->if_link_state = LINK_STATE_DOWN;
859 		if_link_state_change(ifp);
860 	}
861 }
862 
863 #if 0
864 static void
865 vtnet_watchdog(struct vtnet_softc *sc)
866 {
867 	struct ifnet *ifp;
868 
869 	ifp = sc->vtnet_ifp;
870 
871 #ifdef VTNET_TX_INTR_MODERATION
872 	vtnet_txeof(sc);
873 #endif
874 
875 	if (sc->vtnet_watchdog_timer == 0 || --sc->vtnet_watchdog_timer)
876 		return;
877 
878 	if_printf(ifp, "watchdog timeout -- resetting\n");
879 #ifdef VTNET_DEBUG
880 	virtqueue_dump(sc->vtnet_tx_vq);
881 #endif
882 	ifp->if_oerrors++;
883 	ifp->if_flags &= ~IFF_RUNNING;
884 	vtnet_init_locked(sc);
885 }
886 #endif
887 
888 static void
889 vtnet_config_change_task(void *arg, int pending)
890 {
891 	struct vtnet_softc *sc;
892 
893 	sc = arg;
894 
895 	lwkt_serialize_enter(&sc->vtnet_slz);
896 	vtnet_update_link_status(sc);
897 	lwkt_serialize_exit(&sc->vtnet_slz);
898 }
899 
900 static int
901 vtnet_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data,struct ucred *cr)
902 {
903 	struct vtnet_softc *sc;
904 	struct ifreq *ifr;
905 	int reinit, mask, error;
906 
907 	sc = ifp->if_softc;
908 	ifr = (struct ifreq *) data;
909 	reinit = 0;
910 	error = 0;
911 
912 	switch (cmd) {
913 	case SIOCSIFMTU:
914 		if (ifr->ifr_mtu < ETHERMIN || ifr->ifr_mtu > VTNET_MAX_MTU)
915 			error = EINVAL;
916 		else if (ifp->if_mtu != ifr->ifr_mtu) {
917 			lwkt_serialize_enter(&sc->vtnet_slz);
918 			error = vtnet_change_mtu(sc, ifr->ifr_mtu);
919 			lwkt_serialize_exit(&sc->vtnet_slz);
920 		}
921 		break;
922 
923 	case SIOCSIFFLAGS:
924 		lwkt_serialize_enter(&sc->vtnet_slz);
925 		if ((ifp->if_flags & IFF_UP) == 0) {
926 			if (ifp->if_flags & IFF_RUNNING)
927 				vtnet_stop(sc);
928 		} else if (ifp->if_flags & IFF_RUNNING) {
929 			if ((ifp->if_flags ^ sc->vtnet_if_flags) &
930 			    (IFF_PROMISC | IFF_ALLMULTI)) {
931 				if (sc->vtnet_flags & VTNET_FLAG_CTRL_RX)
932 					vtnet_rx_filter(sc);
933 				else
934 					error = ENOTSUP;
935 			}
936 		} else
937 			vtnet_init_locked(sc);
938 
939 		if (error == 0)
940 			sc->vtnet_if_flags = ifp->if_flags;
941 		lwkt_serialize_exit(&sc->vtnet_slz);
942 		break;
943 
944 	case SIOCADDMULTI:
945 	case SIOCDELMULTI:
946 		lwkt_serialize_enter(&sc->vtnet_slz);
947 		if ((sc->vtnet_flags & VTNET_FLAG_CTRL_RX) &&
948 		    (ifp->if_flags & IFF_RUNNING))
949 			vtnet_rx_filter_mac(sc);
950 		lwkt_serialize_exit(&sc->vtnet_slz);
951 		break;
952 
953 	case SIOCSIFMEDIA:
954 	case SIOCGIFMEDIA:
955 		error = ifmedia_ioctl(ifp, ifr, &sc->vtnet_media, cmd);
956 		break;
957 
958 	case SIOCSIFCAP:
959 		mask = ifr->ifr_reqcap ^ ifp->if_capenable;
960 
961 		lwkt_serialize_enter(&sc->vtnet_slz);
962 
963 		if (mask & IFCAP_TXCSUM) {
964 			ifp->if_capenable ^= IFCAP_TXCSUM;
965 			if (ifp->if_capenable & IFCAP_TXCSUM)
966 				ifp->if_hwassist |= VTNET_CSUM_OFFLOAD;
967 			else
968 				ifp->if_hwassist &= ~VTNET_CSUM_OFFLOAD;
969 		}
970 
971 		if (mask & IFCAP_TSO4) {
972 			ifp->if_capenable ^= IFCAP_TSO4;
973 			if (ifp->if_capenable & IFCAP_TSO4)
974 				ifp->if_hwassist |= CSUM_TSO;
975 			else
976 				ifp->if_hwassist &= ~CSUM_TSO;
977 		}
978 
979 		if (mask & IFCAP_RXCSUM) {
980 			ifp->if_capenable ^= IFCAP_RXCSUM;
981 			reinit = 1;
982 		}
983 
984 #if 0	/* IFCAP_LRO doesn't exist in DragonFly. */
985 		if (mask & IFCAP_LRO) {
986 			ifp->if_capenable ^= IFCAP_LRO;
987 			reinit = 1;
988 		}
989 #endif
990 
991 		if (mask & IFCAP_VLAN_HWFILTER) {
992 			ifp->if_capenable ^= IFCAP_VLAN_HWFILTER;
993 			reinit = 1;
994 		}
995 
996 		if (mask & IFCAP_VLAN_HWTSO)
997 			ifp->if_capenable ^= IFCAP_VLAN_HWTSO;
998 
999 		if (mask & IFCAP_VLAN_HWTAGGING)
1000 			ifp->if_capenable ^= IFCAP_VLAN_HWTAGGING;
1001 
1002 		if (reinit && (ifp->if_flags & IFF_RUNNING)) {
1003 			ifp->if_flags &= ~IFF_RUNNING;
1004 			vtnet_init_locked(sc);
1005 		}
1006 		//VLAN_CAPABILITIES(ifp);
1007 
1008 		lwkt_serialize_exit(&sc->vtnet_slz);
1009 		break;
1010 
1011 	default:
1012 		error = ether_ioctl(ifp, cmd, data);
1013 		break;
1014 	}
1015 
1016 	return (error);
1017 }
1018 
1019 static int
1020 vtnet_change_mtu(struct vtnet_softc *sc, int new_mtu)
1021 {
1022 	struct ifnet *ifp;
1023 	int new_frame_size, clsize;
1024 
1025 	ifp = sc->vtnet_ifp;
1026 
1027 	if ((sc->vtnet_flags & VTNET_FLAG_MRG_RXBUFS) == 0) {
1028 		new_frame_size = sizeof(struct vtnet_rx_header) +
1029 		    sizeof(struct ether_vlan_header) + new_mtu;
1030 
1031 		if (new_frame_size > MJUM9BYTES)
1032 			return (EINVAL);
1033 
1034 		if (new_frame_size <= MCLBYTES)
1035 			clsize = MCLBYTES;
1036 		else
1037 			clsize = MJUM9BYTES;
1038 	} else {
1039 		new_frame_size = sizeof(struct virtio_net_hdr_mrg_rxbuf) +
1040 		    sizeof(struct ether_vlan_header) + new_mtu;
1041 
1042 		if (new_frame_size <= MCLBYTES)
1043 			clsize = MCLBYTES;
1044 		else
1045 			clsize = MJUMPAGESIZE;
1046 	}
1047 
1048 	sc->vtnet_rx_mbuf_size = clsize;
1049 	sc->vtnet_rx_mbuf_count = VTNET_NEEDED_RX_MBUFS(sc);
1050 	KASSERT(sc->vtnet_rx_mbuf_count < VTNET_MAX_RX_SEGS,
1051 	    ("too many rx mbufs: %d", sc->vtnet_rx_mbuf_count));
1052 
1053 	ifp->if_mtu = new_mtu;
1054 
1055 	if (ifp->if_flags & IFF_RUNNING) {
1056 		ifp->if_flags &= ~IFF_RUNNING;
1057 		vtnet_init_locked(sc);
1058 	}
1059 
1060 	return (0);
1061 }
1062 
1063 static int
1064 vtnet_init_rx_vq(struct vtnet_softc *sc)
1065 {
1066 	struct virtqueue *vq;
1067 	int nbufs, error;
1068 
1069 	vq = sc->vtnet_rx_vq;
1070 	nbufs = 0;
1071 	error = ENOSPC;
1072 
1073 	while (!virtqueue_full(vq)) {
1074 		if ((error = vtnet_newbuf(sc)) != 0)
1075 			break;
1076 		nbufs++;
1077 	}
1078 
1079 	if (nbufs > 0) {
1080 		virtqueue_notify(vq, &sc->vtnet_slz);
1081 
1082 		/*
1083 		 * EMSGSIZE signifies the virtqueue did not have enough
1084 		 * entries available to hold the last mbuf. This is not
1085 		 * an error. We should not get ENOSPC since we check if
1086 		 * the virtqueue is full before attempting to add a
1087 		 * buffer.
1088 		 */
1089 		if (error == EMSGSIZE)
1090 			error = 0;
1091 	}
1092 
1093 	return (error);
1094 }
1095 
1096 static void
1097 vtnet_free_rx_mbufs(struct vtnet_softc *sc)
1098 {
1099 	struct virtqueue *vq;
1100 	struct mbuf *m;
1101 	int last;
1102 
1103 	vq = sc->vtnet_rx_vq;
1104 	last = 0;
1105 
1106 	while ((m = virtqueue_drain(vq, &last)) != NULL)
1107 		m_freem(m);
1108 
1109 	KASSERT(virtqueue_empty(vq), ("mbufs remaining in Rx Vq"));
1110 }
1111 
1112 static void
1113 vtnet_free_tx_mbufs(struct vtnet_softc *sc)
1114 {
1115 	struct virtqueue *vq;
1116 	struct vtnet_tx_header *txhdr;
1117 	int last;
1118 
1119 	vq = sc->vtnet_tx_vq;
1120 	last = 0;
1121 
1122 	while ((txhdr = virtqueue_drain(vq, &last)) != NULL) {
1123 		m_freem(txhdr->vth_mbuf);
1124 		vtnet_enqueue_txhdr(sc, txhdr);
1125 	}
1126 
1127 	KASSERT(virtqueue_empty(vq), ("mbufs remaining in Tx Vq"));
1128 }
1129 
1130 static void
1131 vtnet_free_ctrl_vq(struct vtnet_softc *sc)
1132 {
1133 	/*
1134 	 * The control virtqueue is only polled, therefore
1135 	 * it should already be empty.
1136 	 */
1137 	KASSERT(virtqueue_empty(sc->vtnet_ctrl_vq),
1138 		("Ctrl Vq not empty"));
1139 }
1140 
1141 static struct mbuf *
1142 vtnet_alloc_rxbuf(struct vtnet_softc *sc, int nbufs, struct mbuf **m_tailp)
1143 {
1144 	struct mbuf *m_head, *m_tail, *m;
1145 	int i, clsize;
1146 
1147 	clsize = sc->vtnet_rx_mbuf_size;
1148 
1149 	/*use getcl instead of getjcl. see  if_mxge.c comment line 2398*/
1150 	//m_head = m_getjcl(M_DONTWAIT, MT_DATA, M_PKTHDR, clsize);
1151 	m_head = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR );
1152 	if (m_head == NULL)
1153 		goto fail;
1154 
1155 	m_head->m_len = clsize;
1156 	m_tail = m_head;
1157 
1158 	if (nbufs > 1) {
1159 		KASSERT(sc->vtnet_flags & VTNET_FLAG_LRO_NOMRG,
1160 			("chained Rx mbuf requested without LRO_NOMRG"));
1161 
1162 		for (i = 0; i < nbufs - 1; i++) {
1163 			//m = m_getjcl(M_DONTWAIT, MT_DATA, 0, clsize);
1164 			m = m_getcl(M_NOWAIT, MT_DATA, 0);
1165 			if (m == NULL)
1166 				goto fail;
1167 
1168 			m->m_len = clsize;
1169 			m_tail->m_next = m;
1170 			m_tail = m;
1171 		}
1172 	}
1173 
1174 	if (m_tailp != NULL)
1175 		*m_tailp = m_tail;
1176 
1177 	return (m_head);
1178 
1179 fail:
1180 	sc->vtnet_stats.mbuf_alloc_failed++;
1181 	m_freem(m_head);
1182 
1183 	return (NULL);
1184 }
1185 
1186 static int
1187 vtnet_replace_rxbuf(struct vtnet_softc *sc, struct mbuf *m0, int len0)
1188 {
1189 	struct mbuf *m, *m_prev;
1190 	struct mbuf *m_new, *m_tail;
1191 	int len, clsize, nreplace, error;
1192 
1193 	m = m0;
1194 	m_prev = NULL;
1195 	len = len0;
1196 
1197 	m_tail = NULL;
1198 	clsize = sc->vtnet_rx_mbuf_size;
1199 	nreplace = 0;
1200 
1201 	if (m->m_next != NULL)
1202 		KASSERT(sc->vtnet_flags & VTNET_FLAG_LRO_NOMRG,
1203 		    ("chained Rx mbuf without LRO_NOMRG"));
1204 
1205 	/*
1206 	 * Since LRO_NOMRG mbuf chains are so large, we want to avoid
1207 	 * allocating an entire chain for each received frame. When
1208 	 * the received frame's length is less than that of the chain,
1209 	 * the unused mbufs are reassigned to the new chain.
1210 	 */
1211 	while (len > 0) {
1212 		/*
1213 		 * Something is seriously wrong if we received
1214 		 * a frame larger than the mbuf chain. Drop it.
1215 		 */
1216 		if (m == NULL) {
1217 			sc->vtnet_stats.rx_frame_too_large++;
1218 			return (EMSGSIZE);
1219 		}
1220 
1221 		KASSERT(m->m_len == clsize,
1222 		    ("mbuf length not expected cluster size: %d",
1223 		    m->m_len));
1224 
1225 		m->m_len = MIN(m->m_len, len);
1226 		len -= m->m_len;
1227 
1228 		m_prev = m;
1229 		m = m->m_next;
1230 		nreplace++;
1231 	}
1232 
1233 	KASSERT(m_prev != NULL, ("m_prev == NULL"));
1234 	KASSERT(nreplace <= sc->vtnet_rx_mbuf_count,
1235 		("too many replacement mbufs: %d/%d", nreplace,
1236 		sc->vtnet_rx_mbuf_count));
1237 
1238 	m_new = vtnet_alloc_rxbuf(sc, nreplace, &m_tail);
1239 	if (m_new == NULL) {
1240 		m_prev->m_len = clsize;
1241 		return (ENOBUFS);
1242 	}
1243 
1244 	/*
1245 	 * Move unused mbufs, if any, from the original chain
1246 	 * onto the end of the new chain.
1247 	 */
1248 	if (m_prev->m_next != NULL) {
1249 		m_tail->m_next = m_prev->m_next;
1250 		m_prev->m_next = NULL;
1251 	}
1252 
1253 	error = vtnet_enqueue_rxbuf(sc, m_new);
1254 	if (error) {
1255 		/*
1256 		 * BAD! We could not enqueue the replacement mbuf chain. We
1257 		 * must restore the m0 chain to the original state if it was
1258 		 * modified so we can subsequently discard it.
1259 		 *
1260 		 * NOTE: The replacement is suppose to be an identical copy
1261 		 * to the one just dequeued so this is an unexpected error.
1262 		 */
1263 		sc->vtnet_stats.rx_enq_replacement_failed++;
1264 
1265 		if (m_tail->m_next != NULL) {
1266 			m_prev->m_next = m_tail->m_next;
1267 			m_tail->m_next = NULL;
1268 		}
1269 
1270 		m_prev->m_len = clsize;
1271 		m_freem(m_new);
1272 	}
1273 
1274 	return (error);
1275 }
1276 
1277 static int
1278 vtnet_newbuf(struct vtnet_softc *sc)
1279 {
1280 	struct mbuf *m;
1281 	int error;
1282 
1283 	m = vtnet_alloc_rxbuf(sc, sc->vtnet_rx_mbuf_count, NULL);
1284 	if (m == NULL)
1285 		return (ENOBUFS);
1286 
1287 	error = vtnet_enqueue_rxbuf(sc, m);
1288 	if (error)
1289 		m_freem(m);
1290 
1291 	return (error);
1292 }
1293 
1294 static void
1295 vtnet_discard_merged_rxbuf(struct vtnet_softc *sc, int nbufs)
1296 {
1297 	struct virtqueue *vq;
1298 	struct mbuf *m;
1299 
1300 	vq = sc->vtnet_rx_vq;
1301 
1302 	while (--nbufs > 0) {
1303 		if ((m = virtqueue_dequeue(vq, NULL)) == NULL)
1304 			break;
1305 		vtnet_discard_rxbuf(sc, m);
1306 	}
1307 }
1308 
1309 static void
1310 vtnet_discard_rxbuf(struct vtnet_softc *sc, struct mbuf *m)
1311 {
1312 	int error;
1313 
1314 	/*
1315 	 * Requeue the discarded mbuf. This should always be
1316 	 * successful since it was just dequeued.
1317 	 */
1318 	error = vtnet_enqueue_rxbuf(sc, m);
1319 	KASSERT(error == 0, ("cannot requeue discarded mbuf"));
1320 }
1321 
1322 static int
1323 vtnet_enqueue_rxbuf(struct vtnet_softc *sc, struct mbuf *m)
1324 {
1325 	struct sglist sg;
1326 	struct sglist_seg segs[VTNET_MAX_RX_SEGS];
1327 	struct vtnet_rx_header *rxhdr;
1328 	struct virtio_net_hdr *hdr;
1329 	uint8_t *mdata;
1330 	int offset, error;
1331 
1332 	ASSERT_SERIALIZED(&sc->vtnet_slz);
1333 	if ((sc->vtnet_flags & VTNET_FLAG_LRO_NOMRG) == 0)
1334 		KASSERT(m->m_next == NULL, ("chained Rx mbuf"));
1335 
1336 	sglist_init(&sg, sc->vtnet_rx_nsegs, segs);
1337 
1338 	mdata = mtod(m, uint8_t *);
1339 	offset = 0;
1340 
1341 	if ((sc->vtnet_flags & VTNET_FLAG_MRG_RXBUFS) == 0) {
1342 		rxhdr = (struct vtnet_rx_header *) mdata;
1343 		hdr = &rxhdr->vrh_hdr;
1344 		offset += sizeof(struct vtnet_rx_header);
1345 
1346 		error = sglist_append(&sg, hdr, sc->vtnet_hdr_size);
1347 		KASSERT(error == 0, ("cannot add header to sglist"));
1348 	}
1349 
1350 	error = sglist_append(&sg, mdata + offset, m->m_len - offset);
1351 	if (error)
1352 		return (error);
1353 
1354 	if (m->m_next != NULL) {
1355 		error = sglist_append_mbuf(&sg, m->m_next);
1356 		if (error)
1357 			return (error);
1358 	}
1359 
1360 	return (virtqueue_enqueue(sc->vtnet_rx_vq, m, &sg, 0, sg.sg_nseg));
1361 }
1362 
1363 static void
1364 vtnet_vlan_tag_remove(struct mbuf *m)
1365 {
1366 	struct ether_vlan_header *evl;
1367 
1368 	evl = mtod(m, struct ether_vlan_header *);
1369 
1370 	m->m_pkthdr.ether_vlantag = ntohs(evl->evl_tag);
1371 	m->m_flags |= M_VLANTAG;
1372 
1373 	/* Strip the 802.1Q header. */
1374 	bcopy((char *) evl, (char *) evl + ETHER_VLAN_ENCAP_LEN,
1375 	    ETHER_HDR_LEN - ETHER_TYPE_LEN);
1376 	m_adj(m, ETHER_VLAN_ENCAP_LEN);
1377 }
1378 
1379 /*
1380  * Alternative method of doing receive checksum offloading. Rather
1381  * than parsing the received frame down to the IP header, use the
1382  * csum_offset to determine which CSUM_* flags are appropriate. We
1383  * can get by with doing this only because the checksum offsets are
1384  * unique for the things we care about.
1385  */
1386 static int
1387 vtnet_rx_csum(struct vtnet_softc *sc, struct mbuf *m,
1388     struct virtio_net_hdr *hdr)
1389 {
1390 	struct ether_header *eh;
1391 	struct ether_vlan_header *evh;
1392 	struct udphdr *udp;
1393 	int csum_len;
1394 	uint16_t eth_type;
1395 
1396 	csum_len = hdr->csum_start + hdr->csum_offset;
1397 
1398 	if (csum_len < sizeof(struct ether_header) + sizeof(struct ip))
1399 		return (1);
1400 	if (m->m_len < csum_len)
1401 		return (1);
1402 
1403 	eh = mtod(m, struct ether_header *);
1404 	eth_type = ntohs(eh->ether_type);
1405 	if (eth_type == ETHERTYPE_VLAN) {
1406 		evh = mtod(m, struct ether_vlan_header *);
1407 		eth_type = ntohs(evh->evl_proto);
1408 	}
1409 
1410 	if (eth_type != ETHERTYPE_IP && eth_type != ETHERTYPE_IPV6) {
1411 		sc->vtnet_stats.rx_csum_bad_ethtype++;
1412 		return (1);
1413 	}
1414 
1415 	/* Use the offset to determine the appropriate CSUM_* flags. */
1416 	switch (hdr->csum_offset) {
1417 	case offsetof(struct udphdr, uh_sum):
1418 		if (m->m_len < hdr->csum_start + sizeof(struct udphdr))
1419 			return (1);
1420 		udp = (struct udphdr *)(mtod(m, uint8_t *) + hdr->csum_start);
1421 		if (udp->uh_sum == 0)
1422 			return (0);
1423 
1424 		/* FALLTHROUGH */
1425 
1426 	case offsetof(struct tcphdr, th_sum):
1427 		m->m_pkthdr.csum_flags |= CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
1428 		m->m_pkthdr.csum_data = 0xFFFF;
1429 		break;
1430 
1431 	default:
1432 		sc->vtnet_stats.rx_csum_bad_offset++;
1433 		return (1);
1434 	}
1435 
1436 	sc->vtnet_stats.rx_csum_offloaded++;
1437 
1438 	return (0);
1439 }
1440 
1441 static int
1442 vtnet_rxeof_merged(struct vtnet_softc *sc, struct mbuf *m_head, int nbufs)
1443 {
1444 	struct ifnet *ifp;
1445 	struct virtqueue *vq;
1446 	struct mbuf *m, *m_tail;
1447 	int len;
1448 
1449 	ifp = sc->vtnet_ifp;
1450 	vq = sc->vtnet_rx_vq;
1451 	m_tail = m_head;
1452 
1453 	while (--nbufs > 0) {
1454 		m = virtqueue_dequeue(vq, &len);
1455 		if (m == NULL) {
1456 			ifp->if_ierrors++;
1457 			goto fail;
1458 		}
1459 
1460 		if (vtnet_newbuf(sc) != 0) {
1461 			ifp->if_iqdrops++;
1462 			vtnet_discard_rxbuf(sc, m);
1463 			if (nbufs > 1)
1464 				vtnet_discard_merged_rxbuf(sc, nbufs);
1465 			goto fail;
1466 		}
1467 
1468 		if (m->m_len < len)
1469 			len = m->m_len;
1470 
1471 		m->m_len = len;
1472 		m->m_flags &= ~M_PKTHDR;
1473 
1474 		m_head->m_pkthdr.len += len;
1475 		m_tail->m_next = m;
1476 		m_tail = m;
1477 	}
1478 
1479 	return (0);
1480 
1481 fail:
1482 	sc->vtnet_stats.rx_mergeable_failed++;
1483 	m_freem(m_head);
1484 
1485 	return (1);
1486 }
1487 
1488 static int
1489 vtnet_rxeof(struct vtnet_softc *sc, int count, int *rx_npktsp)
1490 {
1491 	struct virtio_net_hdr lhdr;
1492 	struct ifnet *ifp;
1493 	struct virtqueue *vq;
1494 	struct mbuf *m;
1495 	struct ether_header *eh;
1496 	struct virtio_net_hdr *hdr;
1497 	struct virtio_net_hdr_mrg_rxbuf *mhdr;
1498 	int len, deq, nbufs, adjsz, rx_npkts;
1499 
1500 	ifp = sc->vtnet_ifp;
1501 	vq = sc->vtnet_rx_vq;
1502 	hdr = &lhdr;
1503 	deq = 0;
1504 	rx_npkts = 0;
1505 
1506 	ASSERT_SERIALIZED(&sc->vtnet_slz);
1507 
1508 	while (--count >= 0) {
1509 		m = virtqueue_dequeue(vq, &len);
1510 		if (m == NULL)
1511 			break;
1512 		deq++;
1513 
1514 		if (len < sc->vtnet_hdr_size + ETHER_HDR_LEN) {
1515 			ifp->if_ierrors++;
1516 			vtnet_discard_rxbuf(sc, m);
1517 			continue;
1518 		}
1519 
1520 		if ((sc->vtnet_flags & VTNET_FLAG_MRG_RXBUFS) == 0) {
1521 			nbufs = 1;
1522 			adjsz = sizeof(struct vtnet_rx_header);
1523 			/*
1524 			 * Account for our pad between the header and
1525 			 * the actual start of the frame.
1526 			 */
1527 			len += VTNET_RX_HEADER_PAD;
1528 		} else {
1529 			mhdr = mtod(m, struct virtio_net_hdr_mrg_rxbuf *);
1530 			nbufs = mhdr->num_buffers;
1531 			adjsz = sizeof(struct virtio_net_hdr_mrg_rxbuf);
1532 		}
1533 
1534 		if (vtnet_replace_rxbuf(sc, m, len) != 0) {
1535 			ifp->if_iqdrops++;
1536 			vtnet_discard_rxbuf(sc, m);
1537 			if (nbufs > 1)
1538 				vtnet_discard_merged_rxbuf(sc, nbufs);
1539 			continue;
1540 		}
1541 
1542 		m->m_pkthdr.len = len;
1543 		m->m_pkthdr.rcvif = ifp;
1544 		m->m_pkthdr.csum_flags = 0;
1545 
1546 		if (nbufs > 1) {
1547 			if (vtnet_rxeof_merged(sc, m, nbufs) != 0)
1548 				continue;
1549 		}
1550 
1551 		ifp->if_ipackets++;
1552 
1553 		/*
1554 		 * Save copy of header before we strip it. For both mergeable
1555 		 * and non-mergeable, the VirtIO header is placed first in the
1556 		 * mbuf's data. We no longer need num_buffers, so always use a
1557 		 * virtio_net_hdr.
1558 		 */
1559 		memcpy(hdr, mtod(m, void *), sizeof(struct virtio_net_hdr));
1560 		m_adj(m, adjsz);
1561 
1562 		if (ifp->if_capenable & IFCAP_VLAN_HWTAGGING) {
1563 			eh = mtod(m, struct ether_header *);
1564 			if (eh->ether_type == htons(ETHERTYPE_VLAN)) {
1565 				vtnet_vlan_tag_remove(m);
1566 
1567 				/*
1568 				 * With the 802.1Q header removed, update the
1569 				 * checksum starting location accordingly.
1570 				 */
1571 				if (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM)
1572 					hdr->csum_start -=
1573 					    ETHER_VLAN_ENCAP_LEN;
1574 			}
1575 		}
1576 
1577 		if (ifp->if_capenable & IFCAP_RXCSUM &&
1578 		    hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
1579 			if (vtnet_rx_csum(sc, m, hdr) != 0)
1580 				sc->vtnet_stats.rx_csum_failed++;
1581 		}
1582 
1583 		lwkt_serialize_exit(&sc->vtnet_slz);
1584 		rx_npkts++;
1585 		ifp->if_input(ifp, m, NULL, -1);
1586 		lwkt_serialize_enter(&sc->vtnet_slz);
1587 
1588 		/*
1589 		 * The interface may have been stopped while we were
1590 		 * passing the packet up the network stack.
1591 		 */
1592 		if ((ifp->if_flags & IFF_RUNNING) == 0)
1593 			break;
1594 	}
1595 
1596 	virtqueue_notify(vq, &sc->vtnet_slz);
1597 
1598 	if (rx_npktsp != NULL)
1599 		*rx_npktsp = rx_npkts;
1600 
1601 	return (count > 0 ? 0 : EAGAIN);
1602 }
1603 
1604 static void
1605 vtnet_rx_intr_task(void *arg)
1606 {
1607 	struct vtnet_softc *sc;
1608 	struct ifnet *ifp;
1609 	int more;
1610 
1611 	sc = arg;
1612 	ifp = sc->vtnet_ifp;
1613 
1614 next:
1615 //	lwkt_serialize_enter(&sc->vtnet_slz);
1616 
1617 	if ((ifp->if_flags & IFF_RUNNING) == 0) {
1618 		vtnet_enable_rx_intr(sc);
1619 //		lwkt_serialize_exit(&sc->vtnet_slz);
1620 		return;
1621 	}
1622 
1623 	more = vtnet_rxeof(sc, sc->vtnet_rx_process_limit, NULL);
1624 	if (!more && vtnet_enable_rx_intr(sc) != 0) {
1625 		vtnet_disable_rx_intr(sc);
1626 		more = 1;
1627 	}
1628 
1629 //	lwkt_serialize_exit(&sc->vtnet_slz);
1630 
1631 	if (more) {
1632 		sc->vtnet_stats.rx_task_rescheduled++;
1633 		goto next;
1634 	}
1635 }
1636 
1637 static void
1638 vtnet_rx_vq_intr(void *xsc)
1639 {
1640 	struct vtnet_softc *sc;
1641 
1642 	sc = xsc;
1643 
1644 	if (!virtqueue_pending(sc->vtnet_rx_vq))
1645 		return;
1646 
1647 	vtnet_disable_rx_intr(sc);
1648 	vtnet_rx_intr_task(sc);
1649 }
1650 
1651 static void
1652 vtnet_enqueue_txhdr(struct vtnet_softc *sc, struct vtnet_tx_header *txhdr)
1653 {
1654 	bzero(txhdr, sizeof(*txhdr));
1655 	SLIST_INSERT_HEAD(&sc->vtnet_txhdr_free, txhdr, link);
1656 }
1657 
1658 static void
1659 vtnet_txeof(struct vtnet_softc *sc)
1660 {
1661 	struct virtqueue *vq;
1662 	struct ifnet *ifp;
1663 	struct vtnet_tx_header *txhdr;
1664 	int deq;
1665 
1666 	vq = sc->vtnet_tx_vq;
1667 	ifp = sc->vtnet_ifp;
1668 	deq = 0;
1669 
1670 	ASSERT_SERIALIZED(&sc->vtnet_slz);
1671 
1672 	while ((txhdr = virtqueue_dequeue(vq, NULL)) != NULL) {
1673 		deq++;
1674 		ifp->if_opackets++;
1675 		m_freem(txhdr->vth_mbuf);
1676 		vtnet_enqueue_txhdr(sc, txhdr);
1677 	}
1678 
1679 	if (deq > 0) {
1680 		ifq_clr_oactive(&ifp->if_snd);
1681 		if (virtqueue_empty(vq))
1682 			sc->vtnet_watchdog_timer = 0;
1683 	}
1684 }
1685 
1686 static struct mbuf *
1687 vtnet_tx_offload(struct vtnet_softc *sc, struct mbuf *m,
1688     struct virtio_net_hdr *hdr)
1689 {
1690 	struct ifnet *ifp;
1691 	struct ether_header *eh;
1692 	struct ether_vlan_header *evh;
1693 	struct ip *ip;
1694 	struct ip6_hdr *ip6;
1695 	struct tcphdr *tcp;
1696 	int ip_offset;
1697 	uint16_t eth_type, csum_start;
1698 	uint8_t ip_proto, gso_type;
1699 
1700 	ifp = sc->vtnet_ifp;
1701 	M_ASSERTPKTHDR(m);
1702 
1703 	ip_offset = sizeof(struct ether_header);
1704 	if (m->m_len < ip_offset) {
1705 		if ((m = m_pullup(m, ip_offset)) == NULL)
1706 			return (NULL);
1707 	}
1708 
1709 	eh = mtod(m, struct ether_header *);
1710 	eth_type = ntohs(eh->ether_type);
1711 	if (eth_type == ETHERTYPE_VLAN) {
1712 		ip_offset = sizeof(struct ether_vlan_header);
1713 		if (m->m_len < ip_offset) {
1714 			if ((m = m_pullup(m, ip_offset)) == NULL)
1715 				return (NULL);
1716 		}
1717 		evh = mtod(m, struct ether_vlan_header *);
1718 		eth_type = ntohs(evh->evl_proto);
1719 	}
1720 
1721 	switch (eth_type) {
1722 	case ETHERTYPE_IP:
1723 		if (m->m_len < ip_offset + sizeof(struct ip)) {
1724 			m = m_pullup(m, ip_offset + sizeof(struct ip));
1725 			if (m == NULL)
1726 				return (NULL);
1727 		}
1728 
1729 		ip = (struct ip *)(mtod(m, uint8_t *) + ip_offset);
1730 		ip_proto = ip->ip_p;
1731 		csum_start = ip_offset + (ip->ip_hl << 2);
1732 		gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
1733 		break;
1734 
1735 	case ETHERTYPE_IPV6:
1736 		if (m->m_len < ip_offset + sizeof(struct ip6_hdr)) {
1737 			m = m_pullup(m, ip_offset + sizeof(struct ip6_hdr));
1738 			if (m == NULL)
1739 				return (NULL);
1740 		}
1741 
1742 		ip6 = (struct ip6_hdr *)(mtod(m, uint8_t *) + ip_offset);
1743 		/*
1744 		 * XXX Assume no extension headers are present. Presently,
1745 		 * this will always be true in the case of TSO, and FreeBSD
1746 		 * does not perform checksum offloading of IPv6 yet.
1747 		 */
1748 		ip_proto = ip6->ip6_nxt;
1749 		csum_start = ip_offset + sizeof(struct ip6_hdr);
1750 		gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
1751 		break;
1752 
1753 	default:
1754 		return (m);
1755 	}
1756 
1757 	if (m->m_pkthdr.csum_flags & VTNET_CSUM_OFFLOAD) {
1758 		hdr->flags |= VIRTIO_NET_HDR_F_NEEDS_CSUM;
1759 		hdr->csum_start = csum_start;
1760 		hdr->csum_offset = m->m_pkthdr.csum_data;
1761 
1762 		sc->vtnet_stats.tx_csum_offloaded++;
1763 	}
1764 
1765 	if (m->m_pkthdr.csum_flags & CSUM_TSO) {
1766 		if (ip_proto != IPPROTO_TCP)
1767 			return (m);
1768 
1769 		if (m->m_len < csum_start + sizeof(struct tcphdr)) {
1770 			m = m_pullup(m, csum_start + sizeof(struct tcphdr));
1771 			if (m == NULL)
1772 				return (NULL);
1773 		}
1774 
1775 		tcp = (struct tcphdr *)(mtod(m, uint8_t *) + csum_start);
1776 		hdr->gso_type = gso_type;
1777 		hdr->hdr_len = csum_start + (tcp->th_off << 2);
1778 		hdr->gso_size = m->m_pkthdr.tso_segsz;
1779 
1780 		if (tcp->th_flags & TH_CWR) {
1781 			/*
1782 			 * Drop if we did not negotiate VIRTIO_NET_F_HOST_ECN.
1783 			 * ECN support is only configurable globally with the
1784 			 * net.inet.tcp.ecn.enable sysctl knob.
1785 			 */
1786 			if ((sc->vtnet_flags & VTNET_FLAG_TSO_ECN) == 0) {
1787 				if_printf(ifp, "TSO with ECN not supported "
1788 				    "by host\n");
1789 				m_freem(m);
1790 				return (NULL);
1791 			}
1792 
1793 			hdr->gso_type |= VIRTIO_NET_HDR_GSO_ECN;
1794 		}
1795 
1796 		sc->vtnet_stats.tx_tso_offloaded++;
1797 	}
1798 
1799 	return (m);
1800 }
1801 
1802 static int
1803 vtnet_enqueue_txbuf(struct vtnet_softc *sc, struct mbuf **m_head,
1804     struct vtnet_tx_header *txhdr)
1805 {
1806 	struct sglist sg;
1807 	struct sglist_seg segs[VTNET_MAX_TX_SEGS];
1808 	struct virtqueue *vq;
1809 	struct mbuf *m;
1810 	int error;
1811 
1812 	vq = sc->vtnet_tx_vq;
1813 	m = *m_head;
1814 
1815 	sglist_init(&sg, sc->vtnet_tx_nsegs, segs);
1816 	error = sglist_append(&sg, &txhdr->vth_uhdr, sc->vtnet_hdr_size);
1817 	KASSERT(error == 0 && sg.sg_nseg == 1,
1818 	    ("%s: error %d adding header to sglist", __func__, error));
1819 
1820 	error = sglist_append_mbuf(&sg, m);
1821 	if (error) {
1822 		m = m_defrag(m, M_NOWAIT);
1823 		if (m == NULL)
1824 			goto fail;
1825 
1826 		*m_head = m;
1827 		sc->vtnet_stats.tx_defragged++;
1828 
1829 		error = sglist_append_mbuf(&sg, m);
1830 		if (error)
1831 			goto fail;
1832 	}
1833 
1834 	txhdr->vth_mbuf = m;
1835 	error = virtqueue_enqueue(vq, txhdr, &sg, sg.sg_nseg, 0);
1836 
1837 	return (error);
1838 
1839 fail:
1840 	sc->vtnet_stats.tx_defrag_failed++;
1841 	m_freem(*m_head);
1842 	*m_head = NULL;
1843 
1844 	return (ENOBUFS);
1845 }
1846 
1847 static struct mbuf *
1848 vtnet_vlan_tag_insert(struct mbuf *m)
1849 {
1850 	struct mbuf *n;
1851 	struct ether_vlan_header *evl;
1852 
1853 	if (M_WRITABLE(m) == 0) {
1854 		n = m_dup(m, M_NOWAIT);
1855 		m_freem(m);
1856 		if ((m = n) == NULL)
1857 			return (NULL);
1858 	}
1859 
1860 	M_PREPEND(m, ETHER_VLAN_ENCAP_LEN, M_NOWAIT);
1861 	if (m == NULL)
1862 		return (NULL);
1863 	if (m->m_len < sizeof(struct ether_vlan_header)) {
1864 		m = m_pullup(m, sizeof(struct ether_vlan_header));
1865 		if (m == NULL)
1866 			return (NULL);
1867 	}
1868 
1869 	/* Insert 802.1Q header into the existing Ethernet header. */
1870 	evl = mtod(m, struct ether_vlan_header *);
1871 	bcopy((char *) evl + ETHER_VLAN_ENCAP_LEN,
1872 	      (char *) evl, ETHER_HDR_LEN - ETHER_TYPE_LEN);
1873 	evl->evl_encap_proto = htons(ETHERTYPE_VLAN);
1874 	evl->evl_tag = htons(m->m_pkthdr.ether_vlantag);
1875 	m->m_flags &= ~M_VLANTAG;
1876 
1877 	return (m);
1878 }
1879 
1880 static int
1881 vtnet_encap(struct vtnet_softc *sc, struct mbuf **m_head)
1882 {
1883 	struct vtnet_tx_header *txhdr;
1884 	struct virtio_net_hdr *hdr;
1885 	struct mbuf *m;
1886 	int error;
1887 
1888 	txhdr = SLIST_FIRST(&sc->vtnet_txhdr_free);
1889 	if (txhdr == NULL)
1890 		return (ENOBUFS);
1891 	SLIST_REMOVE_HEAD(&sc->vtnet_txhdr_free, link);
1892 
1893 	/*
1894 	 * Always use the non-mergeable header to simplify things. When
1895 	 * the mergeable feature is negotiated, the num_buffers field
1896 	 * must be set to zero. We use vtnet_hdr_size later to enqueue
1897 	 * the correct header size to the host.
1898 	 */
1899 	hdr = &txhdr->vth_uhdr.hdr;
1900 	m = *m_head;
1901 
1902 	error = ENOBUFS;
1903 
1904 	if (m->m_flags & M_VLANTAG) {
1905 		//m = ether_vlanencap(m, m->m_pkthdr.ether_vtag);
1906 		m = vtnet_vlan_tag_insert(m);
1907 		if ((*m_head = m) == NULL)
1908 			goto fail;
1909 		m->m_flags &= ~M_VLANTAG;
1910 	}
1911 
1912 	if (m->m_pkthdr.csum_flags != 0) {
1913 		m = vtnet_tx_offload(sc, m, hdr);
1914 		if ((*m_head = m) == NULL)
1915 			goto fail;
1916 	}
1917 
1918 	error = vtnet_enqueue_txbuf(sc, m_head, txhdr);
1919 fail:
1920 	if (error != 0)
1921 		vtnet_enqueue_txhdr(sc, txhdr);
1922 	return (error);
1923 }
1924 
1925 static void
1926 vtnet_start(struct ifnet *ifp, struct ifaltq_subque *ifsq)
1927 {
1928 	struct vtnet_softc *sc;
1929 
1930 	sc = ifp->if_softc;
1931 
1932 	ASSERT_ALTQ_SQ_DEFAULT(ifp, ifsq);
1933 	lwkt_serialize_enter(&sc->vtnet_slz);
1934 	vtnet_start_locked(ifp, ifsq);
1935 	lwkt_serialize_exit(&sc->vtnet_slz);
1936 }
1937 
1938 static void
1939 vtnet_start_locked(struct ifnet *ifp, struct ifaltq_subque *ifsq)
1940 {
1941 	struct vtnet_softc *sc;
1942 	struct virtqueue *vq;
1943 	struct mbuf *m0;
1944 	int enq;
1945 
1946 	sc = ifp->if_softc;
1947 	vq = sc->vtnet_tx_vq;
1948 	enq = 0;
1949 
1950 	ASSERT_SERIALIZED(&sc->vtnet_slz);
1951 
1952 	if ((ifp->if_flags & (IFF_RUNNING)) !=
1953 	    IFF_RUNNING || ((sc->vtnet_flags & VTNET_FLAG_LINK) == 0))
1954 		return;
1955 
1956 #ifdef VTNET_TX_INTR_MODERATION
1957 	if (virtqueue_nused(vq) >= sc->vtnet_tx_size / 2)
1958 		vtnet_txeof(sc);
1959 #endif
1960 
1961 	while (!ifsq_is_empty(ifsq)) {
1962 		if (virtqueue_full(vq)) {
1963 			ifq_set_oactive(&ifp->if_snd);
1964 			break;
1965 		}
1966 
1967 		m0 = ifq_dequeue(&ifp->if_snd);
1968 		if (m0 == NULL)
1969 			break;
1970 
1971 		if (vtnet_encap(sc, &m0) != 0) {
1972 			if (m0 == NULL)
1973 				break;
1974 			ifq_prepend(&ifp->if_snd, m0);
1975 			ifq_set_oactive(&ifp->if_snd);
1976 			break;
1977 		}
1978 
1979 		enq++;
1980 		ETHER_BPF_MTAP(ifp, m0);
1981 	}
1982 
1983 	if (enq > 0) {
1984 		virtqueue_notify(vq, &sc->vtnet_slz);
1985 		sc->vtnet_watchdog_timer = VTNET_WATCHDOG_TIMEOUT;
1986 	}
1987 }
1988 
1989 static void
1990 vtnet_tick(void *xsc)
1991 {
1992 	struct vtnet_softc *sc;
1993 
1994 	sc = xsc;
1995 
1996 #if 0
1997 	ASSERT_SERIALIZED(&sc->vtnet_slz);
1998 #ifdef VTNET_DEBUG
1999 	virtqueue_dump(sc->vtnet_rx_vq);
2000 	virtqueue_dump(sc->vtnet_tx_vq);
2001 #endif
2002 
2003 	vtnet_watchdog(sc);
2004 	callout_reset(&sc->vtnet_tick_ch, hz, vtnet_tick, sc);
2005 #endif
2006 }
2007 
2008 static void
2009 vtnet_tx_intr_task(void *arg)
2010 {
2011 	struct vtnet_softc *sc;
2012 	struct ifnet *ifp;
2013 	struct ifaltq_subque *ifsq;
2014 
2015 	sc = arg;
2016 	ifp = sc->vtnet_ifp;
2017 	ifsq = ifq_get_subq_default(&ifp->if_snd);
2018 
2019 next:
2020 //	lwkt_serialize_enter(&sc->vtnet_slz);
2021 
2022 	if ((ifp->if_flags & IFF_RUNNING) == 0) {
2023 		vtnet_enable_tx_intr(sc);
2024 //		lwkt_serialize_exit(&sc->vtnet_slz);
2025 		return;
2026 	}
2027 
2028 	vtnet_txeof(sc);
2029 
2030 	if (!ifsq_is_empty(ifsq))
2031 		vtnet_start_locked(ifp, ifsq);
2032 
2033 	if (vtnet_enable_tx_intr(sc) != 0) {
2034 		vtnet_disable_tx_intr(sc);
2035 		sc->vtnet_stats.tx_task_rescheduled++;
2036 //		lwkt_serialize_exit(&sc->vtnet_slz);
2037 		goto next;
2038 	}
2039 
2040 //	lwkt_serialize_exit(&sc->vtnet_slz);
2041 }
2042 
2043 static void
2044 vtnet_tx_vq_intr(void *xsc)
2045 {
2046 	struct vtnet_softc *sc;
2047 
2048 	sc = xsc;
2049 
2050 	if (!virtqueue_pending(sc->vtnet_tx_vq))
2051 		return;
2052 
2053 	vtnet_disable_tx_intr(sc);
2054 	vtnet_tx_intr_task(sc);
2055 }
2056 
2057 static void
2058 vtnet_config_intr(void *arg)
2059 {
2060 	struct vtnet_softc *sc;
2061 
2062 	sc = arg;
2063 
2064 	taskqueue_enqueue(taskqueue_thread[mycpuid], &sc->vtnet_cfgchg_task);
2065 }
2066 
2067 static void
2068 vtnet_stop(struct vtnet_softc *sc)
2069 {
2070 	device_t dev;
2071 	struct ifnet *ifp;
2072 
2073 	dev = sc->vtnet_dev;
2074 	ifp = sc->vtnet_ifp;
2075 
2076 	ASSERT_SERIALIZED(&sc->vtnet_slz);
2077 
2078 	sc->vtnet_watchdog_timer = 0;
2079 	callout_stop(&sc->vtnet_tick_ch);
2080 	ifq_clr_oactive(&ifp->if_snd);
2081 	ifp->if_flags &= ~(IFF_RUNNING);
2082 
2083 	vtnet_disable_rx_intr(sc);
2084 	vtnet_disable_tx_intr(sc);
2085 
2086 	/*
2087 	 * Stop the host VirtIO adapter. Note this will reset the host
2088 	 * adapter's state back to the pre-initialized state, so in
2089 	 * order to make the device usable again, we must drive it
2090 	 * through virtio_reinit() and virtio_reinit_complete().
2091 	 */
2092 	virtio_stop(dev);
2093 
2094 	sc->vtnet_flags &= ~VTNET_FLAG_LINK;
2095 
2096 	vtnet_free_rx_mbufs(sc);
2097 	vtnet_free_tx_mbufs(sc);
2098 }
2099 
2100 static int
2101 vtnet_virtio_reinit(struct vtnet_softc *sc)
2102 {
2103 	device_t dev;
2104 	struct ifnet *ifp;
2105 	uint64_t features;
2106 	int error;
2107 
2108 	dev = sc->vtnet_dev;
2109 	ifp = sc->vtnet_ifp;
2110 	features = sc->vtnet_features;
2111 
2112 	/*
2113 	 * Re-negotiate with the host, removing any disabled receive
2114 	 * features. Transmit features are disabled only on our side
2115 	 * via if_capenable and if_hwassist.
2116 	 */
2117 
2118 	if (ifp->if_capabilities & IFCAP_RXCSUM) {
2119 		if ((ifp->if_capenable & IFCAP_RXCSUM) == 0)
2120 			features &= ~VIRTIO_NET_F_GUEST_CSUM;
2121 	}
2122 
2123 #if 0	/* IFCAP_LRO doesn't exist in DragonFly. */
2124 	if (ifp->if_capabilities & IFCAP_LRO) {
2125 		if ((ifp->if_capenable & IFCAP_LRO) == 0)
2126 			features &= ~VTNET_LRO_FEATURES;
2127 	}
2128 #endif
2129 
2130 	if (ifp->if_capabilities & IFCAP_VLAN_HWFILTER) {
2131 		if ((ifp->if_capenable & IFCAP_VLAN_HWFILTER) == 0)
2132 			features &= ~VIRTIO_NET_F_CTRL_VLAN;
2133 	}
2134 
2135 	error = virtio_reinit(dev, features);
2136 	if (error)
2137 		device_printf(dev, "virtio reinit error %d\n", error);
2138 
2139 	return (error);
2140 }
2141 
2142 static void
2143 vtnet_init_locked(struct vtnet_softc *sc)
2144 {
2145 	device_t dev;
2146 	struct ifnet *ifp;
2147 	int error;
2148 
2149 	dev = sc->vtnet_dev;
2150 	ifp = sc->vtnet_ifp;
2151 
2152 	ASSERT_SERIALIZED(&sc->vtnet_slz);
2153 
2154 	if (ifp->if_flags & IFF_RUNNING)
2155 		return;
2156 
2157 	/* Stop host's adapter, cancel any pending I/O. */
2158 	vtnet_stop(sc);
2159 
2160 	/* Reinitialize the host device. */
2161 	error = vtnet_virtio_reinit(sc);
2162 	if (error) {
2163 		device_printf(dev,
2164 		    "reinitialization failed, stopping device...\n");
2165 		vtnet_stop(sc);
2166 		return;
2167 	}
2168 
2169 	/* Update host with assigned MAC address. */
2170 	bcopy(IF_LLADDR(ifp), sc->vtnet_hwaddr, ETHER_ADDR_LEN);
2171 	vtnet_set_hwaddr(sc);
2172 
2173 	ifp->if_hwassist = 0;
2174 	if (ifp->if_capenable & IFCAP_TXCSUM)
2175 		ifp->if_hwassist |= VTNET_CSUM_OFFLOAD;
2176 	if (ifp->if_capenable & IFCAP_TSO4)
2177 		ifp->if_hwassist |= CSUM_TSO;
2178 
2179 	error = vtnet_init_rx_vq(sc);
2180 	if (error) {
2181 		device_printf(dev,
2182 		    "cannot allocate mbufs for Rx virtqueue\n");
2183 		vtnet_stop(sc);
2184 		return;
2185 	}
2186 
2187 	if (sc->vtnet_flags & VTNET_FLAG_CTRL_VQ) {
2188 		if (sc->vtnet_flags & VTNET_FLAG_CTRL_RX) {
2189 			/* Restore promiscuous and all-multicast modes. */
2190 			vtnet_rx_filter(sc);
2191 
2192 			/* Restore filtered MAC addresses. */
2193 			vtnet_rx_filter_mac(sc);
2194 		}
2195 
2196 		/* Restore VLAN filters. */
2197 		if (ifp->if_capenable & IFCAP_VLAN_HWFILTER)
2198 			vtnet_rx_filter_vlan(sc);
2199 	}
2200 
2201 	{
2202 		vtnet_enable_rx_intr(sc);
2203 		vtnet_enable_tx_intr(sc);
2204 	}
2205 
2206 	ifp->if_flags |= IFF_RUNNING;
2207 	ifq_clr_oactive(&ifp->if_snd);
2208 
2209 	virtio_reinit_complete(dev);
2210 
2211 	vtnet_update_link_status(sc);
2212 	callout_reset(&sc->vtnet_tick_ch, hz, vtnet_tick, sc);
2213 }
2214 
2215 static void
2216 vtnet_init(void *xsc)
2217 {
2218 	struct vtnet_softc *sc;
2219 
2220 	sc = xsc;
2221 
2222 	lwkt_serialize_enter(&sc->vtnet_slz);
2223 	vtnet_init_locked(sc);
2224 	lwkt_serialize_exit(&sc->vtnet_slz);
2225 }
2226 
2227 static void
2228 vtnet_exec_ctrl_cmd(struct vtnet_softc *sc, void *cookie,
2229     struct sglist *sg, int readable, int writable)
2230 {
2231 	struct virtqueue *vq;
2232 	void *c;
2233 
2234 	vq = sc->vtnet_ctrl_vq;
2235 
2236 	ASSERT_SERIALIZED(&sc->vtnet_slz);
2237 	KASSERT(sc->vtnet_flags & VTNET_FLAG_CTRL_VQ,
2238 	    ("no control virtqueue"));
2239 	KASSERT(virtqueue_empty(vq),
2240 	    ("control command already enqueued"));
2241 
2242 	if (virtqueue_enqueue(vq, cookie, sg, readable, writable) != 0)
2243 		return;
2244 
2245 	virtqueue_notify(vq, &sc->vtnet_slz);
2246 
2247 	/*
2248 	 * Poll until the command is complete. Previously, we would
2249 	 * sleep until the control virtqueue interrupt handler woke
2250 	 * us up, but dropping the VTNET_MTX leads to serialization
2251 	 * difficulties.
2252 	 *
2253 	 * Furthermore, it appears QEMU/KVM only allocates three MSIX
2254 	 * vectors. Two of those vectors are needed for the Rx and Tx
2255 	 * virtqueues. We do not support sharing both a Vq and config
2256 	 * changed notification on the same MSIX vector.
2257 	 */
2258 	c = virtqueue_poll(vq, NULL);
2259 	KASSERT(c == cookie, ("unexpected control command response"));
2260 }
2261 
2262 static int
2263 vtnet_ctrl_mac_cmd(struct vtnet_softc *sc, uint8_t *hwaddr)
2264 {
2265 	struct {
2266 		struct virtio_net_ctrl_hdr hdr __aligned(2);
2267 		uint8_t pad1;
2268 		char aligned_hwaddr[ETHER_ADDR_LEN] __aligned(8);
2269 		uint8_t pad2;
2270 		uint8_t ack;
2271 	} s;
2272 	struct sglist_seg segs[3];
2273 	struct sglist sg;
2274 	int error;
2275 
2276 	s.hdr.class = VIRTIO_NET_CTRL_MAC;
2277 	s.hdr.cmd = VIRTIO_NET_CTRL_MAC_ADDR_SET;
2278 	s.ack = VIRTIO_NET_ERR;
2279 
2280 	/* Copy the mac address into physically contiguous memory */
2281 	memcpy(s.aligned_hwaddr, hwaddr, ETHER_ADDR_LEN);
2282 
2283 	sglist_init(&sg, 3, segs);
2284 	error = 0;
2285 	error |= sglist_append(&sg, &s.hdr,
2286 	    sizeof(struct virtio_net_ctrl_hdr));
2287 	error |= sglist_append(&sg, s.aligned_hwaddr, ETHER_ADDR_LEN);
2288 	error |= sglist_append(&sg, &s.ack, sizeof(uint8_t));
2289 	KASSERT(error == 0 && sg.sg_nseg == 3,
2290 	    ("%s: error %d adding set MAC msg to sglist", __func__, error));
2291 
2292 	vtnet_exec_ctrl_cmd(sc, &s.ack, &sg, sg.sg_nseg - 1, 1);
2293 
2294 	return (s.ack == VIRTIO_NET_OK ? 0 : EIO);
2295 }
2296 
2297 static void
2298 vtnet_rx_filter(struct vtnet_softc *sc)
2299 {
2300 	device_t dev;
2301 	struct ifnet *ifp;
2302 
2303 	dev = sc->vtnet_dev;
2304 	ifp = sc->vtnet_ifp;
2305 
2306 	ASSERT_SERIALIZED(&sc->vtnet_slz);
2307 	KASSERT(sc->vtnet_flags & VTNET_FLAG_CTRL_RX,
2308 	    ("CTRL_RX feature not negotiated"));
2309 
2310 	if (vtnet_set_promisc(sc, ifp->if_flags & IFF_PROMISC) != 0)
2311 		device_printf(dev, "cannot %s promiscuous mode\n",
2312 		    (ifp->if_flags & IFF_PROMISC) ? "enable" : "disable");
2313 
2314 	if (vtnet_set_allmulti(sc, ifp->if_flags & IFF_ALLMULTI) != 0)
2315 		device_printf(dev, "cannot %s all-multicast mode\n",
2316 		    (ifp->if_flags & IFF_ALLMULTI) ? "enable" : "disable");
2317 }
2318 
2319 static int
2320 vtnet_ctrl_rx_cmd(struct vtnet_softc *sc, int cmd, int on)
2321 {
2322 	struct sglist_seg segs[3];
2323 	struct sglist sg;
2324 	struct {
2325 		struct virtio_net_ctrl_hdr hdr __aligned(2);
2326 		uint8_t pad1;
2327 		uint8_t onoff;
2328 		uint8_t pad2;
2329 		uint8_t ack;
2330 	} s;
2331 	int error;
2332 
2333 	KASSERT(sc->vtnet_flags & VTNET_FLAG_CTRL_RX,
2334 	    ("%s: CTRL_RX feature not negotiated", __func__));
2335 
2336 	s.hdr.class = VIRTIO_NET_CTRL_RX;
2337 	s.hdr.cmd = cmd;
2338 	s.onoff = !!on;
2339 	s.ack = VIRTIO_NET_ERR;
2340 
2341 	sglist_init(&sg, 3, segs);
2342 	error = 0;
2343 	error |= sglist_append(&sg, &s.hdr, sizeof(struct virtio_net_ctrl_hdr));
2344 	error |= sglist_append(&sg, &s.onoff, sizeof(uint8_t));
2345 	error |= sglist_append(&sg, &s.ack, sizeof(uint8_t));
2346 	KASSERT(error == 0 && sg.sg_nseg == 3,
2347 	    ("%s: error %d adding Rx message to sglist", __func__, error));
2348 
2349 	vtnet_exec_ctrl_cmd(sc, &s.ack, &sg, sg.sg_nseg - 1, 1);
2350 
2351 	return (s.ack == VIRTIO_NET_OK ? 0 : EIO);
2352 }
2353 
2354 static int
2355 vtnet_set_promisc(struct vtnet_softc *sc, int on)
2356 {
2357 
2358 	return (vtnet_ctrl_rx_cmd(sc, VIRTIO_NET_CTRL_RX_PROMISC, on));
2359 }
2360 
2361 static int
2362 vtnet_set_allmulti(struct vtnet_softc *sc, int on)
2363 {
2364 
2365 	return (vtnet_ctrl_rx_cmd(sc, VIRTIO_NET_CTRL_RX_ALLMULTI, on));
2366 }
2367 
2368 static void
2369 vtnet_rx_filter_mac(struct vtnet_softc *sc)
2370 {
2371 	struct virtio_net_ctrl_hdr hdr __aligned(2);
2372 	struct vtnet_mac_filter *filter;
2373 	struct sglist_seg segs[4];
2374 	struct sglist sg;
2375 	struct ifnet *ifp;
2376 	struct ifaddr *ifa;
2377         struct ifaddr_container *ifac;
2378 	struct ifmultiaddr *ifma;
2379 	int ucnt, mcnt, promisc, allmulti, error;
2380 	uint8_t ack;
2381 
2382 	ifp = sc->vtnet_ifp;
2383 	ucnt = 0;
2384 	mcnt = 0;
2385 	promisc = 0;
2386 	allmulti = 0;
2387 
2388 	ASSERT_SERIALIZED(&sc->vtnet_slz);
2389 	KASSERT(sc->vtnet_flags & VTNET_FLAG_CTRL_RX,
2390 	    ("%s: CTRL_RX feature not negotiated", __func__));
2391 
2392 	/* Use the MAC filtering table allocated in vtnet_attach. */
2393 	filter = sc->vtnet_macfilter;
2394 	memset(filter, 0, sizeof(struct vtnet_mac_filter));
2395 
2396 	/* Unicast MAC addresses: */
2397 	//if_addr_rlock(ifp);
2398 	TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) {
2399 		ifa = ifac->ifa;
2400 		if (ifa->ifa_addr->sa_family != AF_LINK)
2401 			continue;
2402 		else if (memcmp(LLADDR((struct sockaddr_dl *)ifa->ifa_addr),
2403 		    sc->vtnet_hwaddr, ETHER_ADDR_LEN) == 0)
2404 			continue;
2405 		else if (ucnt == VTNET_MAX_MAC_ENTRIES) {
2406 			promisc = 1;
2407 			break;
2408 		}
2409 
2410 		bcopy(LLADDR((struct sockaddr_dl *)ifa->ifa_addr),
2411 		    &filter->vmf_unicast.macs[ucnt], ETHER_ADDR_LEN);
2412 		ucnt++;
2413 	}
2414 	//if_addr_runlock(ifp);
2415 
2416 	if (promisc != 0) {
2417 		filter->vmf_unicast.nentries = 0;
2418 		if_printf(ifp, "more than %d MAC addresses assigned, "
2419 		    "falling back to promiscuous mode\n",
2420 		    VTNET_MAX_MAC_ENTRIES);
2421 	} else
2422 		filter->vmf_unicast.nentries = ucnt;
2423 
2424 	/* Multicast MAC addresses: */
2425 	//if_maddr_rlock(ifp);
2426 	TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
2427 		if (ifma->ifma_addr->sa_family != AF_LINK)
2428 			continue;
2429 		else if (mcnt == VTNET_MAX_MAC_ENTRIES) {
2430 			allmulti = 1;
2431 			break;
2432 		}
2433 
2434 		bcopy(LLADDR((struct sockaddr_dl *)ifma->ifma_addr),
2435 		    &filter->vmf_multicast.macs[mcnt], ETHER_ADDR_LEN);
2436 		mcnt++;
2437 	}
2438 	//if_maddr_runlock(ifp);
2439 
2440 	if (allmulti != 0) {
2441 		filter->vmf_multicast.nentries = 0;
2442 		if_printf(ifp, "more than %d multicast MAC addresses "
2443 		    "assigned, falling back to all-multicast mode\n",
2444 		    VTNET_MAX_MAC_ENTRIES);
2445 	} else
2446 		filter->vmf_multicast.nentries = mcnt;
2447 
2448 	if (promisc != 0 && allmulti != 0)
2449 		goto out;
2450 
2451 	hdr.class = VIRTIO_NET_CTRL_MAC;
2452 	hdr.cmd = VIRTIO_NET_CTRL_MAC_TABLE_SET;
2453 	ack = VIRTIO_NET_ERR;
2454 
2455 	sglist_init(&sg, 4, segs);
2456 	error = 0;
2457 	error |= sglist_append(&sg, &hdr, sizeof(struct virtio_net_ctrl_hdr));
2458 	error |= sglist_append(&sg, &filter->vmf_unicast,
2459 	    sizeof(uint32_t) + filter->vmf_unicast.nentries * ETHER_ADDR_LEN);
2460 	error |= sglist_append(&sg, &filter->vmf_multicast,
2461 	    sizeof(uint32_t) + filter->vmf_multicast.nentries * ETHER_ADDR_LEN);
2462 	error |= sglist_append(&sg, &ack, sizeof(uint8_t));
2463 	KASSERT(error == 0 && sg.sg_nseg == 4,
2464 	    ("%s: error %d adding MAC filter msg to sglist", __func__, error));
2465 
2466 	vtnet_exec_ctrl_cmd(sc, &ack, &sg, sg.sg_nseg - 1, 1);
2467 
2468 	if (ack != VIRTIO_NET_OK)
2469 		if_printf(ifp, "error setting host MAC filter table\n");
2470 
2471 out:
2472 	if (promisc != 0 && vtnet_set_promisc(sc, 1) != 0)
2473 		if_printf(ifp, "cannot enable promiscuous mode\n");
2474 	if (allmulti != 0 && vtnet_set_allmulti(sc, 1) != 0)
2475 		if_printf(ifp, "cannot enable all-multicast mode\n");
2476 }
2477 
2478 static int
2479 vtnet_exec_vlan_filter(struct vtnet_softc *sc, int add, uint16_t tag)
2480 {
2481 	struct sglist_seg segs[3];
2482 	struct sglist sg;
2483 	struct {
2484 		struct virtio_net_ctrl_hdr hdr __aligned(2);
2485 		uint8_t pad1;
2486 		uint16_t tag;
2487 		uint8_t pad2;
2488 		uint8_t ack;
2489 	} s;
2490 	int error;
2491 
2492 	s.hdr.class = VIRTIO_NET_CTRL_VLAN;
2493 	s.hdr.cmd = add ? VIRTIO_NET_CTRL_VLAN_ADD : VIRTIO_NET_CTRL_VLAN_DEL;
2494 	s.tag = tag;
2495 	s.ack = VIRTIO_NET_ERR;
2496 
2497 	sglist_init(&sg, 3, segs);
2498 	error = 0;
2499 	error |= sglist_append(&sg, &s.hdr, sizeof(struct virtio_net_ctrl_hdr));
2500 	error |= sglist_append(&sg, &s.tag, sizeof(uint16_t));
2501 	error |= sglist_append(&sg, &s.ack, sizeof(uint8_t));
2502 	KASSERT(error == 0 && sg.sg_nseg == 3,
2503 	    ("%s: error %d adding VLAN message to sglist", __func__, error));
2504 
2505 	vtnet_exec_ctrl_cmd(sc, &s.ack, &sg, sg.sg_nseg - 1, 1);
2506 
2507 	return (s.ack == VIRTIO_NET_OK ? 0 : EIO);
2508 }
2509 
2510 static void
2511 vtnet_rx_filter_vlan(struct vtnet_softc *sc)
2512 {
2513 	uint32_t w;
2514 	uint16_t tag;
2515 	int i, bit, nvlans;
2516 
2517 	ASSERT_SERIALIZED(&sc->vtnet_slz);
2518 	KASSERT(sc->vtnet_flags & VTNET_FLAG_VLAN_FILTER,
2519 	    ("%s: VLAN_FILTER feature not negotiated", __func__));
2520 
2521 	nvlans = sc->vtnet_nvlans;
2522 
2523 	/* Enable the filter for each configured VLAN. */
2524 	for (i = 0; i < VTNET_VLAN_SHADOW_SIZE && nvlans > 0; i++) {
2525 		w = sc->vtnet_vlan_shadow[i];
2526 		while ((bit = ffs(w) - 1) != -1) {
2527 			w &= ~(1 << bit);
2528 			tag = sizeof(w) * CHAR_BIT * i + bit;
2529 			nvlans--;
2530 
2531 			if (vtnet_exec_vlan_filter(sc, 1, tag) != 0) {
2532 				device_printf(sc->vtnet_dev,
2533 				    "cannot enable VLAN %d filter\n", tag);
2534 			}
2535 		}
2536 	}
2537 
2538 	KASSERT(nvlans == 0, ("VLAN count incorrect"));
2539 }
2540 
2541 static void
2542 vtnet_update_vlan_filter(struct vtnet_softc *sc, int add, uint16_t tag)
2543 {
2544 	struct ifnet *ifp;
2545 	int idx, bit;
2546 
2547 	ifp = sc->vtnet_ifp;
2548 	idx = (tag >> 5) & 0x7F;
2549 	bit = tag & 0x1F;
2550 
2551 	if (tag == 0 || tag > 4095)
2552 		return;
2553 
2554 	lwkt_serialize_enter(&sc->vtnet_slz);
2555 
2556 	/* Update shadow VLAN table. */
2557 	if (add) {
2558 		sc->vtnet_nvlans++;
2559 		sc->vtnet_vlan_shadow[idx] |= (1 << bit);
2560 	} else {
2561 		sc->vtnet_nvlans--;
2562 		sc->vtnet_vlan_shadow[idx] &= ~(1 << bit);
2563 	}
2564 
2565 	if (ifp->if_capenable & IFCAP_VLAN_HWFILTER &&
2566 	    vtnet_exec_vlan_filter(sc, add, tag) != 0) {
2567 		device_printf(sc->vtnet_dev,
2568 		    "cannot %s VLAN %d %s the host filter table\n",
2569 		    add ? "add" : "remove", tag, add ? "to" : "from");
2570 	}
2571 
2572 	lwkt_serialize_exit(&sc->vtnet_slz);
2573 }
2574 
2575 static void
2576 vtnet_register_vlan(void *arg, struct ifnet *ifp, uint16_t tag)
2577 {
2578 
2579 	if (ifp->if_softc != arg)
2580 		return;
2581 
2582 	vtnet_update_vlan_filter(arg, 1, tag);
2583 }
2584 
2585 static void
2586 vtnet_unregister_vlan(void *arg, struct ifnet *ifp, uint16_t tag)
2587 {
2588 
2589 	if (ifp->if_softc != arg)
2590 		return;
2591 
2592 	vtnet_update_vlan_filter(arg, 0, tag);
2593 }
2594 
2595 static int
2596 vtnet_ifmedia_upd(struct ifnet *ifp)
2597 {
2598 	struct vtnet_softc *sc;
2599 	struct ifmedia *ifm;
2600 
2601 	sc = ifp->if_softc;
2602 	ifm = &sc->vtnet_media;
2603 
2604 	if (IFM_TYPE(ifm->ifm_media) != IFM_ETHER)
2605 		return (EINVAL);
2606 
2607 	return (0);
2608 }
2609 
2610 static void
2611 vtnet_ifmedia_sts(struct ifnet *ifp, struct ifmediareq *ifmr)
2612 {
2613 	struct vtnet_softc *sc;
2614 
2615 	sc = ifp->if_softc;
2616 
2617 	ifmr->ifm_status = IFM_AVALID;
2618 	ifmr->ifm_active = IFM_ETHER;
2619 
2620 	lwkt_serialize_enter(&sc->vtnet_slz);
2621 	if (vtnet_is_link_up(sc) != 0) {
2622 		ifmr->ifm_status |= IFM_ACTIVE;
2623 		ifmr->ifm_active |= VTNET_MEDIATYPE;
2624 	} else
2625 		ifmr->ifm_active |= IFM_NONE;
2626 	lwkt_serialize_exit(&sc->vtnet_slz);
2627 }
2628 
2629 static void
2630 vtnet_add_statistics(struct vtnet_softc *sc)
2631 {
2632 	device_t dev;
2633 	struct vtnet_statistics *stats;
2634 	struct sysctl_ctx_list *ctx;
2635 	struct sysctl_oid *tree;
2636 	struct sysctl_oid_list *child;
2637 
2638 	dev = sc->vtnet_dev;
2639 	stats = &sc->vtnet_stats;
2640 	ctx = device_get_sysctl_ctx(dev);
2641 	tree = device_get_sysctl_tree(dev);
2642 	child = SYSCTL_CHILDREN(tree);
2643 
2644 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "mbuf_alloc_failed",
2645 	    CTLFLAG_RD, &stats->mbuf_alloc_failed, 0,
2646 	    "Mbuf cluster allocation failures");
2647 
2648 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "rx_frame_too_large",
2649 	    CTLFLAG_RD, &stats->rx_frame_too_large, 0,
2650 	    "Received frame larger than the mbuf chain");
2651 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "rx_enq_replacement_failed",
2652 	    CTLFLAG_RD, &stats->rx_enq_replacement_failed, 0,
2653 	    "Enqueuing the replacement receive mbuf failed");
2654 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "rx_mergeable_failed",
2655 	    CTLFLAG_RD, &stats->rx_mergeable_failed, 0,
2656 	    "Mergeable buffers receive failures");
2657 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "rx_csum_bad_ethtype",
2658 	    CTLFLAG_RD, &stats->rx_csum_bad_ethtype, 0,
2659 	    "Received checksum offloaded buffer with unsupported "
2660 	    "Ethernet type");
2661 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "rx_csum_bad_ipproto",
2662 	    CTLFLAG_RD, &stats->rx_csum_bad_ipproto, 0,
2663 	    "Received checksum offloaded buffer with incorrect IP protocol");
2664 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "rx_csum_bad_offset",
2665 	    CTLFLAG_RD, &stats->rx_csum_bad_offset, 0,
2666 	    "Received checksum offloaded buffer with incorrect offset");
2667 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "rx_csum_failed",
2668 	    CTLFLAG_RD, &stats->rx_csum_failed, 0,
2669 	    "Received buffer checksum offload failed");
2670 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "rx_csum_offloaded",
2671 	    CTLFLAG_RD, &stats->rx_csum_offloaded, 0,
2672 	    "Received buffer checksum offload succeeded");
2673 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "rx_task_rescheduled",
2674 	    CTLFLAG_RD, &stats->rx_task_rescheduled, 0,
2675 	    "Times the receive interrupt task rescheduled itself");
2676 
2677 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "tx_csum_bad_ethtype",
2678 	    CTLFLAG_RD, &stats->tx_csum_bad_ethtype, 0,
2679 	    "Aborted transmit of checksum offloaded buffer with unknown "
2680 	    "Ethernet type");
2681 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "tx_tso_bad_ethtype",
2682 	    CTLFLAG_RD, &stats->tx_tso_bad_ethtype, 0,
2683 	    "Aborted transmit of TSO buffer with unknown Ethernet type");
2684 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "tx_defragged",
2685 	    CTLFLAG_RD, &stats->tx_defragged, 0,
2686 	    "Transmit mbufs defragged");
2687 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "tx_defrag_failed",
2688 	    CTLFLAG_RD, &stats->tx_defrag_failed, 0,
2689 	    "Aborted transmit of buffer because defrag failed");
2690 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "tx_csum_offloaded",
2691 	    CTLFLAG_RD, &stats->tx_csum_offloaded, 0,
2692 	    "Offloaded checksum of transmitted buffer");
2693 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "tx_tso_offloaded",
2694 	    CTLFLAG_RD, &stats->tx_tso_offloaded, 0,
2695 	    "Segmentation offload of transmitted buffer");
2696 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "tx_task_rescheduled",
2697 	    CTLFLAG_RD, &stats->tx_task_rescheduled, 0,
2698 	    "Times the transmit interrupt task rescheduled itself");
2699 }
2700 
2701 static int
2702 vtnet_enable_rx_intr(struct vtnet_softc *sc)
2703 {
2704 
2705 	return (virtqueue_enable_intr(sc->vtnet_rx_vq));
2706 }
2707 
2708 static void
2709 vtnet_disable_rx_intr(struct vtnet_softc *sc)
2710 {
2711 
2712 	virtqueue_disable_intr(sc->vtnet_rx_vq);
2713 }
2714 
2715 static int
2716 vtnet_enable_tx_intr(struct vtnet_softc *sc)
2717 {
2718 
2719 #ifdef VTNET_TX_INTR_MODERATION
2720 	return (0);
2721 #else
2722 	return (virtqueue_enable_intr(sc->vtnet_tx_vq));
2723 #endif
2724 }
2725 
2726 static void
2727 vtnet_disable_tx_intr(struct vtnet_softc *sc)
2728 {
2729 
2730 	virtqueue_disable_intr(sc->vtnet_tx_vq);
2731 }
2732