xref: /freebsd/sys/dev/virtio/network/if_vtnet.c (revision fd45b686)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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/param.h>
32 #include <sys/eventhandler.h>
33 #include <sys/systm.h>
34 #include <sys/kernel.h>
35 #include <sys/sockio.h>
36 #include <sys/malloc.h>
37 #include <sys/mbuf.h>
38 #include <sys/module.h>
39 #include <sys/msan.h>
40 #include <sys/socket.h>
41 #include <sys/sysctl.h>
42 #include <sys/random.h>
43 #include <sys/sglist.h>
44 #include <sys/lock.h>
45 #include <sys/mutex.h>
46 #include <sys/taskqueue.h>
47 #include <sys/smp.h>
48 #include <machine/smp.h>
49 
50 #include <vm/uma.h>
51 
52 #include <net/debugnet.h>
53 #include <net/ethernet.h>
54 #include <net/pfil.h>
55 #include <net/if.h>
56 #include <net/if_var.h>
57 #include <net/if_arp.h>
58 #include <net/if_dl.h>
59 #include <net/if_types.h>
60 #include <net/if_media.h>
61 #include <net/if_vlan_var.h>
62 
63 #include <net/bpf.h>
64 
65 #include <netinet/in_systm.h>
66 #include <netinet/in.h>
67 #include <netinet/ip.h>
68 #include <netinet/ip6.h>
69 #include <netinet6/ip6_var.h>
70 #include <netinet/udp.h>
71 #include <netinet/tcp.h>
72 #include <netinet/tcp_lro.h>
73 
74 #include <machine/bus.h>
75 #include <machine/resource.h>
76 #include <sys/bus.h>
77 #include <sys/rman.h>
78 
79 #include <dev/virtio/virtio.h>
80 #include <dev/virtio/virtqueue.h>
81 #include <dev/virtio/network/virtio_net.h>
82 #include <dev/virtio/network/if_vtnetvar.h>
83 #include "virtio_if.h"
84 
85 #include "opt_inet.h"
86 #include "opt_inet6.h"
87 
88 #if defined(INET) || defined(INET6)
89 #include <machine/in_cksum.h>
90 #endif
91 
92 static int	vtnet_modevent(module_t, int, void *);
93 
94 static int	vtnet_probe(device_t);
95 static int	vtnet_attach(device_t);
96 static int	vtnet_detach(device_t);
97 static int	vtnet_suspend(device_t);
98 static int	vtnet_resume(device_t);
99 static int	vtnet_shutdown(device_t);
100 static int	vtnet_attach_completed(device_t);
101 static int	vtnet_config_change(device_t);
102 
103 static int	vtnet_negotiate_features(struct vtnet_softc *);
104 static int	vtnet_setup_features(struct vtnet_softc *);
105 static int	vtnet_init_rxq(struct vtnet_softc *, int);
106 static int	vtnet_init_txq(struct vtnet_softc *, int);
107 static int	vtnet_alloc_rxtx_queues(struct vtnet_softc *);
108 static void	vtnet_free_rxtx_queues(struct vtnet_softc *);
109 static int	vtnet_alloc_rx_filters(struct vtnet_softc *);
110 static void	vtnet_free_rx_filters(struct vtnet_softc *);
111 static int	vtnet_alloc_virtqueues(struct vtnet_softc *);
112 static int	vtnet_alloc_interface(struct vtnet_softc *);
113 static int	vtnet_setup_interface(struct vtnet_softc *);
114 static int	vtnet_ioctl_mtu(struct vtnet_softc *, u_int);
115 static int	vtnet_ioctl_ifflags(struct vtnet_softc *);
116 static int	vtnet_ioctl_multi(struct vtnet_softc *);
117 static int	vtnet_ioctl_ifcap(struct vtnet_softc *, struct ifreq *);
118 static int	vtnet_ioctl(if_t, u_long, caddr_t);
119 static uint64_t	vtnet_get_counter(if_t, ift_counter);
120 
121 static int	vtnet_rxq_populate(struct vtnet_rxq *);
122 static void	vtnet_rxq_free_mbufs(struct vtnet_rxq *);
123 static struct mbuf *
124 		vtnet_rx_alloc_buf(struct vtnet_softc *, int , struct mbuf **);
125 static int	vtnet_rxq_replace_lro_nomrg_buf(struct vtnet_rxq *,
126 		    struct mbuf *, int);
127 static int	vtnet_rxq_replace_buf(struct vtnet_rxq *, struct mbuf *, int);
128 static int	vtnet_rxq_enqueue_buf(struct vtnet_rxq *, struct mbuf *);
129 static int	vtnet_rxq_new_buf(struct vtnet_rxq *);
130 static int	vtnet_rxq_csum_needs_csum(struct vtnet_rxq *, struct mbuf *,
131 		     uint16_t, int, struct virtio_net_hdr *);
132 static int	vtnet_rxq_csum_data_valid(struct vtnet_rxq *, struct mbuf *,
133 		     uint16_t, int, struct virtio_net_hdr *);
134 static int	vtnet_rxq_csum(struct vtnet_rxq *, struct mbuf *,
135 		     struct virtio_net_hdr *);
136 static void	vtnet_rxq_discard_merged_bufs(struct vtnet_rxq *, int);
137 static void	vtnet_rxq_discard_buf(struct vtnet_rxq *, struct mbuf *);
138 static int	vtnet_rxq_merged_eof(struct vtnet_rxq *, struct mbuf *, int);
139 static void	vtnet_rxq_input(struct vtnet_rxq *, struct mbuf *,
140 		    struct virtio_net_hdr *);
141 static int	vtnet_rxq_eof(struct vtnet_rxq *);
142 static void	vtnet_rx_vq_process(struct vtnet_rxq *rxq, int tries);
143 static void	vtnet_rx_vq_intr(void *);
144 static void	vtnet_rxq_tq_intr(void *, int);
145 
146 static int	vtnet_txq_intr_threshold(struct vtnet_txq *);
147 static int	vtnet_txq_below_threshold(struct vtnet_txq *);
148 static int	vtnet_txq_notify(struct vtnet_txq *);
149 static void	vtnet_txq_free_mbufs(struct vtnet_txq *);
150 static int	vtnet_txq_offload_ctx(struct vtnet_txq *, struct mbuf *,
151 		    int *, int *, int *);
152 static int	vtnet_txq_offload_tso(struct vtnet_txq *, struct mbuf *, int,
153 		    int, struct virtio_net_hdr *);
154 static struct mbuf *
155 		vtnet_txq_offload(struct vtnet_txq *, struct mbuf *,
156 		    struct virtio_net_hdr *);
157 static int	vtnet_txq_enqueue_buf(struct vtnet_txq *, struct mbuf **,
158 		    struct vtnet_tx_header *);
159 static int	vtnet_txq_encap(struct vtnet_txq *, struct mbuf **, int);
160 #ifdef VTNET_LEGACY_TX
161 static void	vtnet_start_locked(struct vtnet_txq *, if_t);
162 static void	vtnet_start(if_t);
163 #else
164 static int	vtnet_txq_mq_start_locked(struct vtnet_txq *, struct mbuf *);
165 static int	vtnet_txq_mq_start(if_t, struct mbuf *);
166 static void	vtnet_txq_tq_deferred(void *, int);
167 #endif
168 static void	vtnet_txq_start(struct vtnet_txq *);
169 static void	vtnet_txq_tq_intr(void *, int);
170 static int	vtnet_txq_eof(struct vtnet_txq *);
171 static void	vtnet_tx_vq_intr(void *);
172 static void	vtnet_tx_start_all(struct vtnet_softc *);
173 
174 #ifndef VTNET_LEGACY_TX
175 static void	vtnet_qflush(if_t);
176 #endif
177 
178 static int	vtnet_watchdog(struct vtnet_txq *);
179 static void	vtnet_accum_stats(struct vtnet_softc *,
180 		    struct vtnet_rxq_stats *, struct vtnet_txq_stats *);
181 static void	vtnet_tick(void *);
182 
183 static void	vtnet_start_taskqueues(struct vtnet_softc *);
184 static void	vtnet_free_taskqueues(struct vtnet_softc *);
185 static void	vtnet_drain_taskqueues(struct vtnet_softc *);
186 
187 static void	vtnet_drain_rxtx_queues(struct vtnet_softc *);
188 static void	vtnet_stop_rendezvous(struct vtnet_softc *);
189 static void	vtnet_stop(struct vtnet_softc *);
190 static int	vtnet_virtio_reinit(struct vtnet_softc *);
191 static void	vtnet_init_rx_filters(struct vtnet_softc *);
192 static int	vtnet_init_rx_queues(struct vtnet_softc *);
193 static int	vtnet_init_tx_queues(struct vtnet_softc *);
194 static int	vtnet_init_rxtx_queues(struct vtnet_softc *);
195 static void	vtnet_set_active_vq_pairs(struct vtnet_softc *);
196 static void	vtnet_update_rx_offloads(struct vtnet_softc *);
197 static int	vtnet_reinit(struct vtnet_softc *);
198 static void	vtnet_init_locked(struct vtnet_softc *, int);
199 static void	vtnet_init(void *);
200 
201 static void	vtnet_free_ctrl_vq(struct vtnet_softc *);
202 static void	vtnet_exec_ctrl_cmd(struct vtnet_softc *, void *,
203 		    struct sglist *, int, int);
204 static int	vtnet_ctrl_mac_cmd(struct vtnet_softc *, uint8_t *);
205 static int	vtnet_ctrl_guest_offloads(struct vtnet_softc *, uint64_t);
206 static int	vtnet_ctrl_mq_cmd(struct vtnet_softc *, uint16_t);
207 static int	vtnet_ctrl_rx_cmd(struct vtnet_softc *, uint8_t, bool);
208 static int	vtnet_set_promisc(struct vtnet_softc *, bool);
209 static int	vtnet_set_allmulti(struct vtnet_softc *, bool);
210 static void	vtnet_rx_filter(struct vtnet_softc *);
211 static void	vtnet_rx_filter_mac(struct vtnet_softc *);
212 static int	vtnet_exec_vlan_filter(struct vtnet_softc *, int, uint16_t);
213 static void	vtnet_rx_filter_vlan(struct vtnet_softc *);
214 static void	vtnet_update_vlan_filter(struct vtnet_softc *, int, uint16_t);
215 static void	vtnet_register_vlan(void *, if_t, uint16_t);
216 static void	vtnet_unregister_vlan(void *, if_t, uint16_t);
217 
218 static void	vtnet_update_speed_duplex(struct vtnet_softc *);
219 static int	vtnet_is_link_up(struct vtnet_softc *);
220 static void	vtnet_update_link_status(struct vtnet_softc *);
221 static int	vtnet_ifmedia_upd(if_t);
222 static void	vtnet_ifmedia_sts(if_t, struct ifmediareq *);
223 static void	vtnet_get_macaddr(struct vtnet_softc *);
224 static void	vtnet_set_macaddr(struct vtnet_softc *);
225 static void	vtnet_attached_set_macaddr(struct vtnet_softc *);
226 static void	vtnet_vlan_tag_remove(struct mbuf *);
227 static void	vtnet_set_rx_process_limit(struct vtnet_softc *);
228 
229 static void	vtnet_setup_rxq_sysctl(struct sysctl_ctx_list *,
230 		    struct sysctl_oid_list *, struct vtnet_rxq *);
231 static void	vtnet_setup_txq_sysctl(struct sysctl_ctx_list *,
232 		    struct sysctl_oid_list *, struct vtnet_txq *);
233 static void	vtnet_setup_queue_sysctl(struct vtnet_softc *);
234 static void	vtnet_load_tunables(struct vtnet_softc *);
235 static void	vtnet_setup_sysctl(struct vtnet_softc *);
236 
237 static int	vtnet_rxq_enable_intr(struct vtnet_rxq *);
238 static void	vtnet_rxq_disable_intr(struct vtnet_rxq *);
239 static int	vtnet_txq_enable_intr(struct vtnet_txq *);
240 static void	vtnet_txq_disable_intr(struct vtnet_txq *);
241 static void	vtnet_enable_rx_interrupts(struct vtnet_softc *);
242 static void	vtnet_enable_tx_interrupts(struct vtnet_softc *);
243 static void	vtnet_enable_interrupts(struct vtnet_softc *);
244 static void	vtnet_disable_rx_interrupts(struct vtnet_softc *);
245 static void	vtnet_disable_tx_interrupts(struct vtnet_softc *);
246 static void	vtnet_disable_interrupts(struct vtnet_softc *);
247 
248 static int	vtnet_tunable_int(struct vtnet_softc *, const char *, int);
249 
250 DEBUGNET_DEFINE(vtnet);
251 
252 #define vtnet_htog16(_sc, _val)	virtio_htog16(vtnet_modern(_sc), _val)
253 #define vtnet_htog32(_sc, _val)	virtio_htog32(vtnet_modern(_sc), _val)
254 #define vtnet_htog64(_sc, _val)	virtio_htog64(vtnet_modern(_sc), _val)
255 #define vtnet_gtoh16(_sc, _val)	virtio_gtoh16(vtnet_modern(_sc), _val)
256 #define vtnet_gtoh32(_sc, _val)	virtio_gtoh32(vtnet_modern(_sc), _val)
257 #define vtnet_gtoh64(_sc, _val)	virtio_gtoh64(vtnet_modern(_sc), _val)
258 
259 /* Tunables. */
260 static SYSCTL_NODE(_hw, OID_AUTO, vtnet, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
261     "VirtIO Net driver parameters");
262 
263 static int vtnet_csum_disable = 0;
264 SYSCTL_INT(_hw_vtnet, OID_AUTO, csum_disable, CTLFLAG_RDTUN,
265     &vtnet_csum_disable, 0, "Disables receive and send checksum offload");
266 
267 static int vtnet_fixup_needs_csum = 0;
268 SYSCTL_INT(_hw_vtnet, OID_AUTO, fixup_needs_csum, CTLFLAG_RDTUN,
269     &vtnet_fixup_needs_csum, 0,
270     "Calculate valid checksum for NEEDS_CSUM packets");
271 
272 static int vtnet_tso_disable = 0;
273 SYSCTL_INT(_hw_vtnet, OID_AUTO, tso_disable, CTLFLAG_RDTUN,
274     &vtnet_tso_disable, 0, "Disables TSO");
275 
276 static int vtnet_lro_disable = 0;
277 SYSCTL_INT(_hw_vtnet, OID_AUTO, lro_disable, CTLFLAG_RDTUN,
278     &vtnet_lro_disable, 0, "Disables hardware LRO");
279 
280 static int vtnet_mq_disable = 0;
281 SYSCTL_INT(_hw_vtnet, OID_AUTO, mq_disable, CTLFLAG_RDTUN,
282     &vtnet_mq_disable, 0, "Disables multiqueue support");
283 
284 static int vtnet_mq_max_pairs = VTNET_MAX_QUEUE_PAIRS;
285 SYSCTL_INT(_hw_vtnet, OID_AUTO, mq_max_pairs, CTLFLAG_RDTUN,
286     &vtnet_mq_max_pairs, 0, "Maximum number of multiqueue pairs");
287 
288 static int vtnet_tso_maxlen = IP_MAXPACKET;
289 SYSCTL_INT(_hw_vtnet, OID_AUTO, tso_maxlen, CTLFLAG_RDTUN,
290     &vtnet_tso_maxlen, 0, "TSO burst limit");
291 
292 static int vtnet_rx_process_limit = 1024;
293 SYSCTL_INT(_hw_vtnet, OID_AUTO, rx_process_limit, CTLFLAG_RDTUN,
294     &vtnet_rx_process_limit, 0,
295     "Number of RX segments processed in one pass");
296 
297 static int vtnet_lro_entry_count = 128;
298 SYSCTL_INT(_hw_vtnet, OID_AUTO, lro_entry_count, CTLFLAG_RDTUN,
299     &vtnet_lro_entry_count, 0, "Software LRO entry count");
300 
301 /* Enable sorted LRO, and the depth of the mbuf queue. */
302 static int vtnet_lro_mbufq_depth = 0;
303 SYSCTL_UINT(_hw_vtnet, OID_AUTO, lro_mbufq_depth, CTLFLAG_RDTUN,
304     &vtnet_lro_mbufq_depth, 0, "Depth of software LRO mbuf queue");
305 
306 static uma_zone_t vtnet_tx_header_zone;
307 
308 static struct virtio_feature_desc vtnet_feature_desc[] = {
309 	{ VIRTIO_NET_F_CSUM,			"TxChecksum"		},
310 	{ VIRTIO_NET_F_GUEST_CSUM,		"RxChecksum"		},
311 	{ VIRTIO_NET_F_CTRL_GUEST_OFFLOADS,	"CtrlRxOffloads"	},
312 	{ VIRTIO_NET_F_MAC,			"MAC"			},
313 	{ VIRTIO_NET_F_GSO,			"TxGSO"			},
314 	{ VIRTIO_NET_F_GUEST_TSO4,		"RxLROv4"		},
315 	{ VIRTIO_NET_F_GUEST_TSO6,		"RxLROv6"		},
316 	{ VIRTIO_NET_F_GUEST_ECN,		"RxLROECN"		},
317 	{ VIRTIO_NET_F_GUEST_UFO,		"RxUFO"			},
318 	{ VIRTIO_NET_F_HOST_TSO4,		"TxTSOv4"		},
319 	{ VIRTIO_NET_F_HOST_TSO6,		"TxTSOv6"		},
320 	{ VIRTIO_NET_F_HOST_ECN,		"TxTSOECN"		},
321 	{ VIRTIO_NET_F_HOST_UFO,		"TxUFO"			},
322 	{ VIRTIO_NET_F_MRG_RXBUF,		"MrgRxBuf"		},
323 	{ VIRTIO_NET_F_STATUS,			"Status"		},
324 	{ VIRTIO_NET_F_CTRL_VQ,			"CtrlVq"		},
325 	{ VIRTIO_NET_F_CTRL_RX,			"CtrlRxMode"		},
326 	{ VIRTIO_NET_F_CTRL_VLAN,		"CtrlVLANFilter"	},
327 	{ VIRTIO_NET_F_CTRL_RX_EXTRA,		"CtrlRxModeExtra"	},
328 	{ VIRTIO_NET_F_GUEST_ANNOUNCE,		"GuestAnnounce"		},
329 	{ VIRTIO_NET_F_MQ,			"Multiqueue"		},
330 	{ VIRTIO_NET_F_CTRL_MAC_ADDR,		"CtrlMacAddr"		},
331 	{ VIRTIO_NET_F_SPEED_DUPLEX,		"SpeedDuplex"		},
332 
333 	{ 0, NULL }
334 };
335 
336 static device_method_t vtnet_methods[] = {
337 	/* Device methods. */
338 	DEVMETHOD(device_probe,			vtnet_probe),
339 	DEVMETHOD(device_attach,		vtnet_attach),
340 	DEVMETHOD(device_detach,		vtnet_detach),
341 	DEVMETHOD(device_suspend,		vtnet_suspend),
342 	DEVMETHOD(device_resume,		vtnet_resume),
343 	DEVMETHOD(device_shutdown,		vtnet_shutdown),
344 
345 	/* VirtIO methods. */
346 	DEVMETHOD(virtio_attach_completed,	vtnet_attach_completed),
347 	DEVMETHOD(virtio_config_change,		vtnet_config_change),
348 
349 	DEVMETHOD_END
350 };
351 
352 #ifdef DEV_NETMAP
353 #include <dev/netmap/if_vtnet_netmap.h>
354 #endif
355 
356 static driver_t vtnet_driver = {
357     .name = "vtnet",
358     .methods = vtnet_methods,
359     .size = sizeof(struct vtnet_softc)
360 };
361 VIRTIO_DRIVER_MODULE(vtnet, vtnet_driver, vtnet_modevent, NULL);
362 MODULE_VERSION(vtnet, 1);
363 MODULE_DEPEND(vtnet, virtio, 1, 1, 1);
364 #ifdef DEV_NETMAP
365 MODULE_DEPEND(vtnet, netmap, 1, 1, 1);
366 #endif
367 
368 VIRTIO_SIMPLE_PNPINFO(vtnet, VIRTIO_ID_NETWORK, "VirtIO Networking Adapter");
369 
370 static int
371 vtnet_modevent(module_t mod __unused, int type, void *unused __unused)
372 {
373 	int error = 0;
374 	static int loaded = 0;
375 
376 	switch (type) {
377 	case MOD_LOAD:
378 		if (loaded++ == 0) {
379 			vtnet_tx_header_zone = uma_zcreate("vtnet_tx_hdr",
380 				sizeof(struct vtnet_tx_header),
381 				NULL, NULL, NULL, NULL, 0, 0);
382 #ifdef DEBUGNET
383 			/*
384 			 * We need to allocate from this zone in the transmit path, so ensure
385 			 * that we have at least one item per header available.
386 			 * XXX add a separate zone like we do for mbufs? otherwise we may alloc
387 			 * buckets
388 			 */
389 			uma_zone_reserve(vtnet_tx_header_zone, DEBUGNET_MAX_IN_FLIGHT * 2);
390 			uma_prealloc(vtnet_tx_header_zone, DEBUGNET_MAX_IN_FLIGHT * 2);
391 #endif
392 		}
393 		break;
394 	case MOD_QUIESCE:
395 		if (uma_zone_get_cur(vtnet_tx_header_zone) > 0)
396 			error = EBUSY;
397 		break;
398 	case MOD_UNLOAD:
399 		if (--loaded == 0) {
400 			uma_zdestroy(vtnet_tx_header_zone);
401 			vtnet_tx_header_zone = NULL;
402 		}
403 		break;
404 	case MOD_SHUTDOWN:
405 		break;
406 	default:
407 		error = EOPNOTSUPP;
408 		break;
409 	}
410 
411 	return (error);
412 }
413 
414 static int
415 vtnet_probe(device_t dev)
416 {
417 	return (VIRTIO_SIMPLE_PROBE(dev, vtnet));
418 }
419 
420 static int
421 vtnet_attach(device_t dev)
422 {
423 	struct vtnet_softc *sc;
424 	int error;
425 
426 	sc = device_get_softc(dev);
427 	sc->vtnet_dev = dev;
428 	virtio_set_feature_desc(dev, vtnet_feature_desc);
429 
430 	VTNET_CORE_LOCK_INIT(sc);
431 	callout_init_mtx(&sc->vtnet_tick_ch, VTNET_CORE_MTX(sc), 0);
432 	vtnet_load_tunables(sc);
433 
434 	error = vtnet_alloc_interface(sc);
435 	if (error) {
436 		device_printf(dev, "cannot allocate interface\n");
437 		goto fail;
438 	}
439 
440 	vtnet_setup_sysctl(sc);
441 
442 	error = vtnet_setup_features(sc);
443 	if (error) {
444 		device_printf(dev, "cannot setup features\n");
445 		goto fail;
446 	}
447 
448 	error = vtnet_alloc_rx_filters(sc);
449 	if (error) {
450 		device_printf(dev, "cannot allocate Rx filters\n");
451 		goto fail;
452 	}
453 
454 	error = vtnet_alloc_rxtx_queues(sc);
455 	if (error) {
456 		device_printf(dev, "cannot allocate queues\n");
457 		goto fail;
458 	}
459 
460 	error = vtnet_alloc_virtqueues(sc);
461 	if (error) {
462 		device_printf(dev, "cannot allocate virtqueues\n");
463 		goto fail;
464 	}
465 
466 	error = vtnet_setup_interface(sc);
467 	if (error) {
468 		device_printf(dev, "cannot setup interface\n");
469 		goto fail;
470 	}
471 
472 	error = virtio_setup_intr(dev, INTR_TYPE_NET);
473 	if (error) {
474 		device_printf(dev, "cannot setup interrupts\n");
475 		ether_ifdetach(sc->vtnet_ifp);
476 		goto fail;
477 	}
478 
479 #ifdef DEV_NETMAP
480 	vtnet_netmap_attach(sc);
481 #endif
482 	vtnet_start_taskqueues(sc);
483 
484 fail:
485 	if (error)
486 		vtnet_detach(dev);
487 
488 	return (error);
489 }
490 
491 static int
492 vtnet_detach(device_t dev)
493 {
494 	struct vtnet_softc *sc;
495 	if_t ifp;
496 
497 	sc = device_get_softc(dev);
498 	ifp = sc->vtnet_ifp;
499 
500 	if (device_is_attached(dev)) {
501 		VTNET_CORE_LOCK(sc);
502 		vtnet_stop(sc);
503 		VTNET_CORE_UNLOCK(sc);
504 
505 		callout_drain(&sc->vtnet_tick_ch);
506 		vtnet_drain_taskqueues(sc);
507 
508 		ether_ifdetach(ifp);
509 	}
510 
511 #ifdef DEV_NETMAP
512 	netmap_detach(ifp);
513 #endif
514 
515 	if (sc->vtnet_pfil != NULL) {
516 		pfil_head_unregister(sc->vtnet_pfil);
517 		sc->vtnet_pfil = NULL;
518 	}
519 
520 	vtnet_free_taskqueues(sc);
521 
522 	if (sc->vtnet_vlan_attach != NULL) {
523 		EVENTHANDLER_DEREGISTER(vlan_config, sc->vtnet_vlan_attach);
524 		sc->vtnet_vlan_attach = NULL;
525 	}
526 	if (sc->vtnet_vlan_detach != NULL) {
527 		EVENTHANDLER_DEREGISTER(vlan_unconfig, sc->vtnet_vlan_detach);
528 		sc->vtnet_vlan_detach = NULL;
529 	}
530 
531 	ifmedia_removeall(&sc->vtnet_media);
532 
533 	if (ifp != NULL) {
534 		if_free(ifp);
535 		sc->vtnet_ifp = NULL;
536 	}
537 
538 	vtnet_free_rxtx_queues(sc);
539 	vtnet_free_rx_filters(sc);
540 
541 	if (sc->vtnet_ctrl_vq != NULL)
542 		vtnet_free_ctrl_vq(sc);
543 
544 	VTNET_CORE_LOCK_DESTROY(sc);
545 
546 	return (0);
547 }
548 
549 static int
550 vtnet_suspend(device_t dev)
551 {
552 	struct vtnet_softc *sc;
553 
554 	sc = device_get_softc(dev);
555 
556 	VTNET_CORE_LOCK(sc);
557 	vtnet_stop(sc);
558 	sc->vtnet_flags |= VTNET_FLAG_SUSPENDED;
559 	VTNET_CORE_UNLOCK(sc);
560 
561 	return (0);
562 }
563 
564 static int
565 vtnet_resume(device_t dev)
566 {
567 	struct vtnet_softc *sc;
568 	if_t ifp;
569 
570 	sc = device_get_softc(dev);
571 	ifp = sc->vtnet_ifp;
572 
573 	VTNET_CORE_LOCK(sc);
574 	if (if_getflags(ifp) & IFF_UP)
575 		vtnet_init_locked(sc, 0);
576 	sc->vtnet_flags &= ~VTNET_FLAG_SUSPENDED;
577 	VTNET_CORE_UNLOCK(sc);
578 
579 	return (0);
580 }
581 
582 static int
583 vtnet_shutdown(device_t dev)
584 {
585 	/*
586 	 * Suspend already does all of what we need to
587 	 * do here; we just never expect to be resumed.
588 	 */
589 	return (vtnet_suspend(dev));
590 }
591 
592 static int
593 vtnet_attach_completed(device_t dev)
594 {
595 	struct vtnet_softc *sc;
596 
597 	sc = device_get_softc(dev);
598 
599 	VTNET_CORE_LOCK(sc);
600 	vtnet_attached_set_macaddr(sc);
601 	VTNET_CORE_UNLOCK(sc);
602 
603 	return (0);
604 }
605 
606 static int
607 vtnet_config_change(device_t dev)
608 {
609 	struct vtnet_softc *sc;
610 
611 	sc = device_get_softc(dev);
612 
613 	VTNET_CORE_LOCK(sc);
614 	vtnet_update_link_status(sc);
615 	if (sc->vtnet_link_active != 0)
616 		vtnet_tx_start_all(sc);
617 	VTNET_CORE_UNLOCK(sc);
618 
619 	return (0);
620 }
621 
622 static int
623 vtnet_negotiate_features(struct vtnet_softc *sc)
624 {
625 	device_t dev;
626 	uint64_t features, negotiated_features;
627 	int no_csum;
628 
629 	dev = sc->vtnet_dev;
630 	features = virtio_bus_is_modern(dev) ? VTNET_MODERN_FEATURES :
631 	    VTNET_LEGACY_FEATURES;
632 
633 	/*
634 	 * TSO and LRO are only available when their corresponding checksum
635 	 * offload feature is also negotiated.
636 	 */
637 	no_csum = vtnet_tunable_int(sc, "csum_disable", vtnet_csum_disable);
638 	if (no_csum)
639 		features &= ~(VIRTIO_NET_F_CSUM | VIRTIO_NET_F_GUEST_CSUM);
640 	if (no_csum || vtnet_tunable_int(sc, "tso_disable", vtnet_tso_disable))
641 		features &= ~VTNET_TSO_FEATURES;
642 	if (no_csum || vtnet_tunable_int(sc, "lro_disable", vtnet_lro_disable))
643 		features &= ~VTNET_LRO_FEATURES;
644 
645 #ifndef VTNET_LEGACY_TX
646 	if (vtnet_tunable_int(sc, "mq_disable", vtnet_mq_disable))
647 		features &= ~VIRTIO_NET_F_MQ;
648 #else
649 	features &= ~VIRTIO_NET_F_MQ;
650 #endif
651 
652 	negotiated_features = virtio_negotiate_features(dev, features);
653 
654 	if (virtio_with_feature(dev, VIRTIO_NET_F_MTU)) {
655 		uint16_t mtu;
656 
657 		mtu = virtio_read_dev_config_2(dev,
658 		    offsetof(struct virtio_net_config, mtu));
659 		if (mtu < VTNET_MIN_MTU /* || mtu > VTNET_MAX_MTU */) {
660 			device_printf(dev, "Invalid MTU value: %d. "
661 			    "MTU feature disabled.\n", mtu);
662 			features &= ~VIRTIO_NET_F_MTU;
663 			negotiated_features =
664 			    virtio_negotiate_features(dev, features);
665 		}
666 	}
667 
668 	if (virtio_with_feature(dev, VIRTIO_NET_F_MQ)) {
669 		uint16_t npairs;
670 
671 		npairs = virtio_read_dev_config_2(dev,
672 		    offsetof(struct virtio_net_config, max_virtqueue_pairs));
673 		if (npairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
674 		    npairs > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX) {
675 			device_printf(dev, "Invalid max_virtqueue_pairs value: "
676 			    "%d. Multiqueue feature disabled.\n", npairs);
677 			features &= ~VIRTIO_NET_F_MQ;
678 			negotiated_features =
679 			    virtio_negotiate_features(dev, features);
680 		}
681 	}
682 
683 	if (virtio_with_feature(dev, VTNET_LRO_FEATURES) &&
684 	    virtio_with_feature(dev, VIRTIO_NET_F_MRG_RXBUF) == 0) {
685 		/*
686 		 * LRO without mergeable buffers requires special care. This
687 		 * is not ideal because every receive buffer must be large
688 		 * enough to hold the maximum TCP packet, the Ethernet header,
689 		 * and the header. This requires up to 34 descriptors with
690 		 * MCLBYTES clusters. If we do not have indirect descriptors,
691 		 * LRO is disabled since the virtqueue will not contain very
692 		 * many receive buffers.
693 		 */
694 		if (!virtio_with_feature(dev, VIRTIO_RING_F_INDIRECT_DESC)) {
695 			device_printf(dev,
696 			    "Host LRO disabled since both mergeable buffers "
697 			    "and indirect descriptors were not negotiated\n");
698 			features &= ~VTNET_LRO_FEATURES;
699 			negotiated_features =
700 			    virtio_negotiate_features(dev, features);
701 		} else
702 			sc->vtnet_flags |= VTNET_FLAG_LRO_NOMRG;
703 	}
704 
705 	sc->vtnet_features = negotiated_features;
706 	sc->vtnet_negotiated_features = negotiated_features;
707 
708 	return (virtio_finalize_features(dev));
709 }
710 
711 static int
712 vtnet_setup_features(struct vtnet_softc *sc)
713 {
714 	device_t dev;
715 	int error;
716 
717 	dev = sc->vtnet_dev;
718 
719 	error = vtnet_negotiate_features(sc);
720 	if (error)
721 		return (error);
722 
723 	if (virtio_with_feature(dev, VIRTIO_F_VERSION_1))
724 		sc->vtnet_flags |= VTNET_FLAG_MODERN;
725 	if (virtio_with_feature(dev, VIRTIO_RING_F_INDIRECT_DESC))
726 		sc->vtnet_flags |= VTNET_FLAG_INDIRECT;
727 	if (virtio_with_feature(dev, VIRTIO_RING_F_EVENT_IDX))
728 		sc->vtnet_flags |= VTNET_FLAG_EVENT_IDX;
729 
730 	if (virtio_with_feature(dev, VIRTIO_NET_F_MAC)) {
731 		/* This feature should always be negotiated. */
732 		sc->vtnet_flags |= VTNET_FLAG_MAC;
733 	}
734 
735 	if (virtio_with_feature(dev, VIRTIO_NET_F_MTU)) {
736 		sc->vtnet_max_mtu = virtio_read_dev_config_2(dev,
737 		    offsetof(struct virtio_net_config, mtu));
738 	} else
739 		sc->vtnet_max_mtu = VTNET_MAX_MTU;
740 
741 	if (virtio_with_feature(dev, VIRTIO_NET_F_MRG_RXBUF)) {
742 		sc->vtnet_flags |= VTNET_FLAG_MRG_RXBUFS;
743 		sc->vtnet_hdr_size = sizeof(struct virtio_net_hdr_mrg_rxbuf);
744 	} else if (vtnet_modern(sc)) {
745 		/* This is identical to the mergeable header. */
746 		sc->vtnet_hdr_size = sizeof(struct virtio_net_hdr_v1);
747 	} else
748 		sc->vtnet_hdr_size = sizeof(struct virtio_net_hdr);
749 
750 	if (vtnet_modern(sc) || sc->vtnet_flags & VTNET_FLAG_MRG_RXBUFS)
751 		sc->vtnet_rx_nsegs = VTNET_RX_SEGS_HDR_INLINE;
752 	else if (sc->vtnet_flags & VTNET_FLAG_LRO_NOMRG)
753 		sc->vtnet_rx_nsegs = VTNET_RX_SEGS_LRO_NOMRG;
754 	else
755 		sc->vtnet_rx_nsegs = VTNET_RX_SEGS_HDR_SEPARATE;
756 
757 	/*
758 	 * Favor "hardware" LRO if negotiated, but support software LRO as
759 	 * a fallback; there is usually little benefit (or worse) with both.
760 	 */
761 	if (virtio_with_feature(dev, VIRTIO_NET_F_GUEST_TSO4) == 0 &&
762 	    virtio_with_feature(dev, VIRTIO_NET_F_GUEST_TSO6) == 0)
763 		sc->vtnet_flags |= VTNET_FLAG_SW_LRO;
764 
765 	if (virtio_with_feature(dev, VIRTIO_NET_F_GSO) ||
766 	    virtio_with_feature(dev, VIRTIO_NET_F_HOST_TSO4) ||
767 	    virtio_with_feature(dev, VIRTIO_NET_F_HOST_TSO6))
768 		sc->vtnet_tx_nsegs = VTNET_TX_SEGS_MAX;
769 	else
770 		sc->vtnet_tx_nsegs = VTNET_TX_SEGS_MIN;
771 
772 	sc->vtnet_req_vq_pairs = 1;
773 	sc->vtnet_max_vq_pairs = 1;
774 
775 	if (virtio_with_feature(dev, VIRTIO_NET_F_CTRL_VQ)) {
776 		sc->vtnet_flags |= VTNET_FLAG_CTRL_VQ;
777 
778 		if (virtio_with_feature(dev, VIRTIO_NET_F_CTRL_RX))
779 			sc->vtnet_flags |= VTNET_FLAG_CTRL_RX;
780 		if (virtio_with_feature(dev, VIRTIO_NET_F_CTRL_VLAN))
781 			sc->vtnet_flags |= VTNET_FLAG_VLAN_FILTER;
782 		if (virtio_with_feature(dev, VIRTIO_NET_F_CTRL_MAC_ADDR))
783 			sc->vtnet_flags |= VTNET_FLAG_CTRL_MAC;
784 
785 		if (virtio_with_feature(dev, VIRTIO_NET_F_MQ)) {
786 			sc->vtnet_max_vq_pairs = virtio_read_dev_config_2(dev,
787 			    offsetof(struct virtio_net_config,
788 			    max_virtqueue_pairs));
789 		}
790 	}
791 
792 	if (sc->vtnet_max_vq_pairs > 1) {
793 		int req;
794 
795 		/*
796 		 * Limit the maximum number of requested queue pairs to the
797 		 * number of CPUs and the configured maximum.
798 		 */
799 		req = vtnet_tunable_int(sc, "mq_max_pairs", vtnet_mq_max_pairs);
800 		if (req < 0)
801 			req = 1;
802 		if (req == 0)
803 			req = mp_ncpus;
804 		if (req > sc->vtnet_max_vq_pairs)
805 			req = sc->vtnet_max_vq_pairs;
806 		if (req > mp_ncpus)
807 			req = mp_ncpus;
808 		if (req > 1) {
809 			sc->vtnet_req_vq_pairs = req;
810 			sc->vtnet_flags |= VTNET_FLAG_MQ;
811 		}
812 	}
813 
814 	return (0);
815 }
816 
817 static int
818 vtnet_init_rxq(struct vtnet_softc *sc, int id)
819 {
820 	struct vtnet_rxq *rxq;
821 
822 	rxq = &sc->vtnet_rxqs[id];
823 
824 	snprintf(rxq->vtnrx_name, sizeof(rxq->vtnrx_name), "%s-rx%d",
825 	    device_get_nameunit(sc->vtnet_dev), id);
826 	mtx_init(&rxq->vtnrx_mtx, rxq->vtnrx_name, NULL, MTX_DEF);
827 
828 	rxq->vtnrx_sc = sc;
829 	rxq->vtnrx_id = id;
830 
831 	rxq->vtnrx_sg = sglist_alloc(sc->vtnet_rx_nsegs, M_NOWAIT);
832 	if (rxq->vtnrx_sg == NULL)
833 		return (ENOMEM);
834 
835 #if defined(INET) || defined(INET6)
836 	if (vtnet_software_lro(sc)) {
837 		if (tcp_lro_init_args(&rxq->vtnrx_lro, sc->vtnet_ifp,
838 		    sc->vtnet_lro_entry_count, sc->vtnet_lro_mbufq_depth) != 0)
839 			return (ENOMEM);
840 	}
841 #endif
842 
843 	NET_TASK_INIT(&rxq->vtnrx_intrtask, 0, vtnet_rxq_tq_intr, rxq);
844 	rxq->vtnrx_tq = taskqueue_create(rxq->vtnrx_name, M_NOWAIT,
845 	    taskqueue_thread_enqueue, &rxq->vtnrx_tq);
846 
847 	return (rxq->vtnrx_tq == NULL ? ENOMEM : 0);
848 }
849 
850 static int
851 vtnet_init_txq(struct vtnet_softc *sc, int id)
852 {
853 	struct vtnet_txq *txq;
854 
855 	txq = &sc->vtnet_txqs[id];
856 
857 	snprintf(txq->vtntx_name, sizeof(txq->vtntx_name), "%s-tx%d",
858 	    device_get_nameunit(sc->vtnet_dev), id);
859 	mtx_init(&txq->vtntx_mtx, txq->vtntx_name, NULL, MTX_DEF);
860 
861 	txq->vtntx_sc = sc;
862 	txq->vtntx_id = id;
863 
864 	txq->vtntx_sg = sglist_alloc(sc->vtnet_tx_nsegs, M_NOWAIT);
865 	if (txq->vtntx_sg == NULL)
866 		return (ENOMEM);
867 
868 #ifndef VTNET_LEGACY_TX
869 	txq->vtntx_br = buf_ring_alloc(VTNET_DEFAULT_BUFRING_SIZE, M_DEVBUF,
870 	    M_NOWAIT, &txq->vtntx_mtx);
871 	if (txq->vtntx_br == NULL)
872 		return (ENOMEM);
873 
874 	TASK_INIT(&txq->vtntx_defrtask, 0, vtnet_txq_tq_deferred, txq);
875 #endif
876 	TASK_INIT(&txq->vtntx_intrtask, 0, vtnet_txq_tq_intr, txq);
877 	txq->vtntx_tq = taskqueue_create(txq->vtntx_name, M_NOWAIT,
878 	    taskqueue_thread_enqueue, &txq->vtntx_tq);
879 	if (txq->vtntx_tq == NULL)
880 		return (ENOMEM);
881 
882 	return (0);
883 }
884 
885 static int
886 vtnet_alloc_rxtx_queues(struct vtnet_softc *sc)
887 {
888 	int i, npairs, error;
889 
890 	npairs = sc->vtnet_max_vq_pairs;
891 
892 	sc->vtnet_rxqs = malloc(sizeof(struct vtnet_rxq) * npairs, M_DEVBUF,
893 	    M_NOWAIT | M_ZERO);
894 	sc->vtnet_txqs = malloc(sizeof(struct vtnet_txq) * npairs, M_DEVBUF,
895 	    M_NOWAIT | M_ZERO);
896 	if (sc->vtnet_rxqs == NULL || sc->vtnet_txqs == NULL)
897 		return (ENOMEM);
898 
899 	for (i = 0; i < npairs; i++) {
900 		error = vtnet_init_rxq(sc, i);
901 		if (error)
902 			return (error);
903 		error = vtnet_init_txq(sc, i);
904 		if (error)
905 			return (error);
906 	}
907 
908 	vtnet_set_rx_process_limit(sc);
909 	vtnet_setup_queue_sysctl(sc);
910 
911 	return (0);
912 }
913 
914 static void
915 vtnet_destroy_rxq(struct vtnet_rxq *rxq)
916 {
917 
918 	rxq->vtnrx_sc = NULL;
919 	rxq->vtnrx_id = -1;
920 
921 #if defined(INET) || defined(INET6)
922 	tcp_lro_free(&rxq->vtnrx_lro);
923 #endif
924 
925 	if (rxq->vtnrx_sg != NULL) {
926 		sglist_free(rxq->vtnrx_sg);
927 		rxq->vtnrx_sg = NULL;
928 	}
929 
930 	if (mtx_initialized(&rxq->vtnrx_mtx) != 0)
931 		mtx_destroy(&rxq->vtnrx_mtx);
932 }
933 
934 static void
935 vtnet_destroy_txq(struct vtnet_txq *txq)
936 {
937 
938 	txq->vtntx_sc = NULL;
939 	txq->vtntx_id = -1;
940 
941 	if (txq->vtntx_sg != NULL) {
942 		sglist_free(txq->vtntx_sg);
943 		txq->vtntx_sg = NULL;
944 	}
945 
946 #ifndef VTNET_LEGACY_TX
947 	if (txq->vtntx_br != NULL) {
948 		buf_ring_free(txq->vtntx_br, M_DEVBUF);
949 		txq->vtntx_br = NULL;
950 	}
951 #endif
952 
953 	if (mtx_initialized(&txq->vtntx_mtx) != 0)
954 		mtx_destroy(&txq->vtntx_mtx);
955 }
956 
957 static void
958 vtnet_free_rxtx_queues(struct vtnet_softc *sc)
959 {
960 	int i;
961 
962 	if (sc->vtnet_rxqs != NULL) {
963 		for (i = 0; i < sc->vtnet_max_vq_pairs; i++)
964 			vtnet_destroy_rxq(&sc->vtnet_rxqs[i]);
965 		free(sc->vtnet_rxqs, M_DEVBUF);
966 		sc->vtnet_rxqs = NULL;
967 	}
968 
969 	if (sc->vtnet_txqs != NULL) {
970 		for (i = 0; i < sc->vtnet_max_vq_pairs; i++)
971 			vtnet_destroy_txq(&sc->vtnet_txqs[i]);
972 		free(sc->vtnet_txqs, M_DEVBUF);
973 		sc->vtnet_txqs = NULL;
974 	}
975 }
976 
977 static int
978 vtnet_alloc_rx_filters(struct vtnet_softc *sc)
979 {
980 
981 	if (sc->vtnet_flags & VTNET_FLAG_CTRL_RX) {
982 		sc->vtnet_mac_filter = malloc(sizeof(struct vtnet_mac_filter),
983 		    M_DEVBUF, M_NOWAIT | M_ZERO);
984 		if (sc->vtnet_mac_filter == NULL)
985 			return (ENOMEM);
986 	}
987 
988 	if (sc->vtnet_flags & VTNET_FLAG_VLAN_FILTER) {
989 		sc->vtnet_vlan_filter = malloc(sizeof(uint32_t) *
990 		    VTNET_VLAN_FILTER_NWORDS, M_DEVBUF, M_NOWAIT | M_ZERO);
991 		if (sc->vtnet_vlan_filter == NULL)
992 			return (ENOMEM);
993 	}
994 
995 	return (0);
996 }
997 
998 static void
999 vtnet_free_rx_filters(struct vtnet_softc *sc)
1000 {
1001 
1002 	if (sc->vtnet_mac_filter != NULL) {
1003 		free(sc->vtnet_mac_filter, M_DEVBUF);
1004 		sc->vtnet_mac_filter = NULL;
1005 	}
1006 
1007 	if (sc->vtnet_vlan_filter != NULL) {
1008 		free(sc->vtnet_vlan_filter, M_DEVBUF);
1009 		sc->vtnet_vlan_filter = NULL;
1010 	}
1011 }
1012 
1013 static int
1014 vtnet_alloc_virtqueues(struct vtnet_softc *sc)
1015 {
1016 	device_t dev;
1017 	struct vq_alloc_info *info;
1018 	struct vtnet_rxq *rxq;
1019 	struct vtnet_txq *txq;
1020 	int i, idx, nvqs, error;
1021 
1022 	dev = sc->vtnet_dev;
1023 
1024 	nvqs = sc->vtnet_max_vq_pairs * 2;
1025 	if (sc->vtnet_flags & VTNET_FLAG_CTRL_VQ)
1026 		nvqs++;
1027 
1028 	info = malloc(sizeof(struct vq_alloc_info) * nvqs, M_TEMP, M_NOWAIT);
1029 	if (info == NULL)
1030 		return (ENOMEM);
1031 
1032 	for (i = 0, idx = 0; i < sc->vtnet_req_vq_pairs; i++, idx += 2) {
1033 		rxq = &sc->vtnet_rxqs[i];
1034 		VQ_ALLOC_INFO_INIT(&info[idx], sc->vtnet_rx_nsegs,
1035 		    vtnet_rx_vq_intr, rxq, &rxq->vtnrx_vq,
1036 		    "%s-rx%d", device_get_nameunit(dev), rxq->vtnrx_id);
1037 
1038 		txq = &sc->vtnet_txqs[i];
1039 		VQ_ALLOC_INFO_INIT(&info[idx+1], sc->vtnet_tx_nsegs,
1040 		    vtnet_tx_vq_intr, txq, &txq->vtntx_vq,
1041 		    "%s-tx%d", device_get_nameunit(dev), txq->vtntx_id);
1042 	}
1043 
1044 	/* These queues will not be used so allocate the minimum resources. */
1045 	for (/**/; i < sc->vtnet_max_vq_pairs; i++, idx += 2) {
1046 		rxq = &sc->vtnet_rxqs[i];
1047 		VQ_ALLOC_INFO_INIT(&info[idx], 0, NULL, rxq, &rxq->vtnrx_vq,
1048 		    "%s-rx%d", device_get_nameunit(dev), rxq->vtnrx_id);
1049 
1050 		txq = &sc->vtnet_txqs[i];
1051 		VQ_ALLOC_INFO_INIT(&info[idx+1], 0, NULL, txq, &txq->vtntx_vq,
1052 		    "%s-tx%d", device_get_nameunit(dev), txq->vtntx_id);
1053 	}
1054 
1055 	if (sc->vtnet_flags & VTNET_FLAG_CTRL_VQ) {
1056 		VQ_ALLOC_INFO_INIT(&info[idx], 0, NULL, NULL,
1057 		    &sc->vtnet_ctrl_vq, "%s ctrl", device_get_nameunit(dev));
1058 	}
1059 
1060 	error = virtio_alloc_virtqueues(dev, nvqs, info);
1061 	free(info, M_TEMP);
1062 
1063 	return (error);
1064 }
1065 
1066 static int
1067 vtnet_alloc_interface(struct vtnet_softc *sc)
1068 {
1069 	device_t dev;
1070 	if_t ifp;
1071 
1072 	dev = sc->vtnet_dev;
1073 
1074 	ifp = if_alloc(IFT_ETHER);
1075 	if (ifp == NULL)
1076 		return (ENOMEM);
1077 
1078 	sc->vtnet_ifp = ifp;
1079 	if_setsoftc(ifp, sc);
1080 	if_initname(ifp, device_get_name(dev), device_get_unit(dev));
1081 
1082 	return (0);
1083 }
1084 
1085 static int
1086 vtnet_setup_interface(struct vtnet_softc *sc)
1087 {
1088 	device_t dev;
1089 	struct pfil_head_args pa;
1090 	if_t ifp;
1091 
1092 	dev = sc->vtnet_dev;
1093 	ifp = sc->vtnet_ifp;
1094 
1095 	if_setflags(ifp, IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST);
1096 	if_setbaudrate(ifp, IF_Gbps(10));
1097 	if_setinitfn(ifp, vtnet_init);
1098 	if_setioctlfn(ifp, vtnet_ioctl);
1099 	if_setgetcounterfn(ifp, vtnet_get_counter);
1100 #ifndef VTNET_LEGACY_TX
1101 	if_settransmitfn(ifp, vtnet_txq_mq_start);
1102 	if_setqflushfn(ifp, vtnet_qflush);
1103 #else
1104 	struct virtqueue *vq = sc->vtnet_txqs[0].vtntx_vq;
1105 	if_setstartfn(ifp, vtnet_start);
1106 	if_setsendqlen(ifp, virtqueue_size(vq) - 1);
1107 	if_setsendqready(ifp);
1108 #endif
1109 
1110 	vtnet_get_macaddr(sc);
1111 
1112 	if (virtio_with_feature(dev, VIRTIO_NET_F_STATUS))
1113 		if_setcapabilitiesbit(ifp, IFCAP_LINKSTATE, 0);
1114 
1115 	ifmedia_init(&sc->vtnet_media, 0, vtnet_ifmedia_upd, vtnet_ifmedia_sts);
1116 	ifmedia_add(&sc->vtnet_media, IFM_ETHER | IFM_AUTO, 0, NULL);
1117 	ifmedia_set(&sc->vtnet_media, IFM_ETHER | IFM_AUTO);
1118 
1119 	if (virtio_with_feature(dev, VIRTIO_NET_F_CSUM)) {
1120 		int gso;
1121 
1122 		if_setcapabilitiesbit(ifp, IFCAP_TXCSUM | IFCAP_TXCSUM_IPV6, 0);
1123 
1124 		gso = virtio_with_feature(dev, VIRTIO_NET_F_GSO);
1125 		if (gso || virtio_with_feature(dev, VIRTIO_NET_F_HOST_TSO4))
1126 			if_setcapabilitiesbit(ifp, IFCAP_TSO4, 0);
1127 		if (gso || virtio_with_feature(dev, VIRTIO_NET_F_HOST_TSO6))
1128 			if_setcapabilitiesbit(ifp, IFCAP_TSO6, 0);
1129 		if (gso || virtio_with_feature(dev, VIRTIO_NET_F_HOST_ECN))
1130 			sc->vtnet_flags |= VTNET_FLAG_TSO_ECN;
1131 
1132 		if (if_getcapabilities(ifp) & (IFCAP_TSO4 | IFCAP_TSO6)) {
1133 			int tso_maxlen;
1134 
1135 			if_setcapabilitiesbit(ifp, IFCAP_VLAN_HWTSO, 0);
1136 
1137 			tso_maxlen = vtnet_tunable_int(sc, "tso_maxlen",
1138 			    vtnet_tso_maxlen);
1139 			if_sethwtsomax(ifp, tso_maxlen -
1140 			    (ETHER_HDR_LEN + ETHER_VLAN_ENCAP_LEN));
1141 			if_sethwtsomaxsegcount(ifp, sc->vtnet_tx_nsegs - 1);
1142 			if_sethwtsomaxsegsize(ifp, PAGE_SIZE);
1143 		}
1144 	}
1145 
1146 	if (virtio_with_feature(dev, VIRTIO_NET_F_GUEST_CSUM)) {
1147 		if_setcapabilitiesbit(ifp, IFCAP_RXCSUM, 0);
1148 #ifdef notyet
1149 		/* BMV: Rx checksums not distinguished between IPv4 and IPv6. */
1150 		if_setcapabilitiesbit(ifp, IFCAP_RXCSUM_IPV6, 0);
1151 #endif
1152 
1153 		if (vtnet_tunable_int(sc, "fixup_needs_csum",
1154 		    vtnet_fixup_needs_csum) != 0)
1155 			sc->vtnet_flags |= VTNET_FLAG_FIXUP_NEEDS_CSUM;
1156 
1157 		/* Support either "hardware" or software LRO. */
1158 		if_setcapabilitiesbit(ifp, IFCAP_LRO, 0);
1159 	}
1160 
1161 	if (if_getcapabilities(ifp) & (IFCAP_HWCSUM | IFCAP_HWCSUM_IPV6)) {
1162 		/*
1163 		 * VirtIO does not support VLAN tagging, but we can fake
1164 		 * it by inserting and removing the 802.1Q header during
1165 		 * transmit and receive. We are then able to do checksum
1166 		 * offloading of VLAN frames.
1167 		 */
1168 		if_setcapabilitiesbit(ifp, IFCAP_VLAN_HWTAGGING | IFCAP_VLAN_HWCSUM, 0);
1169 	}
1170 
1171 	if (sc->vtnet_max_mtu >= ETHERMTU_JUMBO)
1172 		if_setcapabilitiesbit(ifp, IFCAP_JUMBO_MTU, 0);
1173 	if_setcapabilitiesbit(ifp, IFCAP_VLAN_MTU, 0);
1174 
1175 	/*
1176 	 * Capabilities after here are not enabled by default.
1177 	 */
1178 	if_setcapenable(ifp, if_getcapabilities(ifp));
1179 
1180 	if (sc->vtnet_flags & VTNET_FLAG_VLAN_FILTER) {
1181 		if_setcapabilitiesbit(ifp, IFCAP_VLAN_HWFILTER, 0);
1182 
1183 		sc->vtnet_vlan_attach = EVENTHANDLER_REGISTER(vlan_config,
1184 		    vtnet_register_vlan, sc, EVENTHANDLER_PRI_FIRST);
1185 		sc->vtnet_vlan_detach = EVENTHANDLER_REGISTER(vlan_unconfig,
1186 		    vtnet_unregister_vlan, sc, EVENTHANDLER_PRI_FIRST);
1187 	}
1188 
1189 	ether_ifattach(ifp, sc->vtnet_hwaddr);
1190 
1191 	/* Tell the upper layer(s) we support long frames. */
1192 	if_setifheaderlen(ifp, sizeof(struct ether_vlan_header));
1193 
1194 	DEBUGNET_SET(ifp, vtnet);
1195 
1196 	pa.pa_version = PFIL_VERSION;
1197 	pa.pa_flags = PFIL_IN;
1198 	pa.pa_type = PFIL_TYPE_ETHERNET;
1199 	pa.pa_headname = if_name(ifp);
1200 	sc->vtnet_pfil = pfil_head_register(&pa);
1201 
1202 	return (0);
1203 }
1204 
1205 static int
1206 vtnet_rx_cluster_size(struct vtnet_softc *sc, int mtu)
1207 {
1208 	int framesz;
1209 
1210 	if (sc->vtnet_flags & VTNET_FLAG_MRG_RXBUFS)
1211 		return (MJUMPAGESIZE);
1212 	else if (sc->vtnet_flags & VTNET_FLAG_LRO_NOMRG)
1213 		return (MCLBYTES);
1214 
1215 	/*
1216 	 * Try to scale the receive mbuf cluster size from the MTU. We
1217 	 * could also use the VQ size to influence the selected size,
1218 	 * but that would only matter for very small queues.
1219 	 */
1220 	if (vtnet_modern(sc)) {
1221 		MPASS(sc->vtnet_hdr_size == sizeof(struct virtio_net_hdr_v1));
1222 		framesz = sizeof(struct virtio_net_hdr_v1);
1223 	} else
1224 		framesz = sizeof(struct vtnet_rx_header);
1225 	framesz += sizeof(struct ether_vlan_header) + mtu;
1226 
1227 	if (framesz <= MCLBYTES)
1228 		return (MCLBYTES);
1229 	else if (framesz <= MJUMPAGESIZE)
1230 		return (MJUMPAGESIZE);
1231 	else if (framesz <= MJUM9BYTES)
1232 		return (MJUM9BYTES);
1233 
1234 	/* Sane default; avoid 16KB clusters. */
1235 	return (MCLBYTES);
1236 }
1237 
1238 static int
1239 vtnet_ioctl_mtu(struct vtnet_softc *sc, u_int mtu)
1240 {
1241 	if_t ifp;
1242 	int clustersz;
1243 
1244 	ifp = sc->vtnet_ifp;
1245 	VTNET_CORE_LOCK_ASSERT(sc);
1246 
1247 	if (if_getmtu(ifp) == mtu)
1248 		return (0);
1249 	else if (mtu < ETHERMIN || mtu > sc->vtnet_max_mtu)
1250 		return (EINVAL);
1251 
1252 	if_setmtu(ifp, mtu);
1253 	clustersz = vtnet_rx_cluster_size(sc, mtu);
1254 
1255 	if (clustersz != sc->vtnet_rx_clustersz &&
1256 	    if_getdrvflags(ifp) & IFF_DRV_RUNNING) {
1257 		if_setdrvflagbits(ifp, 0, IFF_DRV_RUNNING);
1258 		vtnet_init_locked(sc, 0);
1259 	}
1260 
1261 	return (0);
1262 }
1263 
1264 static int
1265 vtnet_ioctl_ifflags(struct vtnet_softc *sc)
1266 {
1267 	if_t ifp;
1268 	int drv_running;
1269 
1270 	ifp = sc->vtnet_ifp;
1271 	drv_running = (if_getdrvflags(ifp) & IFF_DRV_RUNNING) != 0;
1272 
1273 	VTNET_CORE_LOCK_ASSERT(sc);
1274 
1275 	if ((if_getflags(ifp) & IFF_UP) == 0) {
1276 		if (drv_running)
1277 			vtnet_stop(sc);
1278 		goto out;
1279 	}
1280 
1281 	if (!drv_running) {
1282 		vtnet_init_locked(sc, 0);
1283 		goto out;
1284 	}
1285 
1286 	if ((if_getflags(ifp) ^ sc->vtnet_if_flags) &
1287 	    (IFF_PROMISC | IFF_ALLMULTI)) {
1288 		if (sc->vtnet_flags & VTNET_FLAG_CTRL_RX)
1289 			vtnet_rx_filter(sc);
1290 		else {
1291 			/*
1292 			 * We don't support filtering out multicast, so
1293 			 * ALLMULTI is always set.
1294 			 */
1295 			if_setflagbits(ifp, IFF_ALLMULTI, 0);
1296 			if_setflagbits(ifp, IFF_PROMISC, 0);
1297 		}
1298 	}
1299 
1300 out:
1301 	sc->vtnet_if_flags = if_getflags(ifp);
1302 	return (0);
1303 }
1304 
1305 static int
1306 vtnet_ioctl_multi(struct vtnet_softc *sc)
1307 {
1308 	if_t ifp;
1309 
1310 	ifp = sc->vtnet_ifp;
1311 
1312 	VTNET_CORE_LOCK_ASSERT(sc);
1313 
1314 	if (sc->vtnet_flags & VTNET_FLAG_CTRL_RX &&
1315 	    if_getdrvflags(ifp) & IFF_DRV_RUNNING)
1316 		vtnet_rx_filter_mac(sc);
1317 
1318 	return (0);
1319 }
1320 
1321 static int
1322 vtnet_ioctl_ifcap(struct vtnet_softc *sc, struct ifreq *ifr)
1323 {
1324 	if_t ifp;
1325 	int mask, reinit, update;
1326 
1327 	ifp = sc->vtnet_ifp;
1328 	mask = (ifr->ifr_reqcap & if_getcapabilities(ifp)) ^ if_getcapenable(ifp);
1329 	reinit = update = 0;
1330 
1331 	VTNET_CORE_LOCK_ASSERT(sc);
1332 
1333 	if (mask & IFCAP_TXCSUM)
1334 		if_togglecapenable(ifp, IFCAP_TXCSUM);
1335 	if (mask & IFCAP_TXCSUM_IPV6)
1336 		if_togglecapenable(ifp, IFCAP_TXCSUM_IPV6);
1337 	if (mask & IFCAP_TSO4)
1338 		if_togglecapenable(ifp, IFCAP_TSO4);
1339 	if (mask & IFCAP_TSO6)
1340 		if_togglecapenable(ifp, IFCAP_TSO6);
1341 
1342 	if (mask & (IFCAP_RXCSUM | IFCAP_RXCSUM_IPV6 | IFCAP_LRO)) {
1343 		/*
1344 		 * These Rx features require the negotiated features to
1345 		 * be updated. Avoid a full reinit if possible.
1346 		 */
1347 		if (sc->vtnet_features & VIRTIO_NET_F_CTRL_GUEST_OFFLOADS)
1348 			update = 1;
1349 		else
1350 			reinit = 1;
1351 
1352 		/* BMV: Avoid needless renegotiation for just software LRO. */
1353 		if ((mask & (IFCAP_RXCSUM | IFCAP_RXCSUM_IPV6 | IFCAP_LRO)) ==
1354 		    IFCAP_LRO && vtnet_software_lro(sc))
1355 			reinit = update = 0;
1356 
1357 		if (mask & IFCAP_RXCSUM)
1358 			if_togglecapenable(ifp, IFCAP_RXCSUM);
1359 		if (mask & IFCAP_RXCSUM_IPV6)
1360 			if_togglecapenable(ifp, IFCAP_RXCSUM_IPV6);
1361 		if (mask & IFCAP_LRO)
1362 			if_togglecapenable(ifp, IFCAP_LRO);
1363 
1364 		/*
1365 		 * VirtIO does not distinguish between IPv4 and IPv6 checksums
1366 		 * so treat them as a pair. Guest TSO (LRO) requires receive
1367 		 * checksums.
1368 		 */
1369 		if (if_getcapenable(ifp) & (IFCAP_RXCSUM | IFCAP_RXCSUM_IPV6)) {
1370 			if_setcapenablebit(ifp, IFCAP_RXCSUM, 0);
1371 #ifdef notyet
1372 			if_setcapenablebit(ifp, IFCAP_RXCSUM_IPV6, 0);
1373 #endif
1374 		} else
1375 			if_setcapenablebit(ifp, 0,
1376 			    (IFCAP_RXCSUM | IFCAP_RXCSUM_IPV6 | IFCAP_LRO));
1377 	}
1378 
1379 	if (mask & IFCAP_VLAN_HWFILTER) {
1380 		/* These Rx features require renegotiation. */
1381 		reinit = 1;
1382 
1383 		if (mask & IFCAP_VLAN_HWFILTER)
1384 			if_togglecapenable(ifp, IFCAP_VLAN_HWFILTER);
1385 	}
1386 
1387 	if (mask & IFCAP_VLAN_HWTSO)
1388 		if_togglecapenable(ifp, IFCAP_VLAN_HWTSO);
1389 	if (mask & IFCAP_VLAN_HWTAGGING)
1390 		if_togglecapenable(ifp, IFCAP_VLAN_HWTAGGING);
1391 
1392 	if (if_getdrvflags(ifp) & IFF_DRV_RUNNING) {
1393 		if (reinit) {
1394 			if_setdrvflagbits(ifp, 0, IFF_DRV_RUNNING);
1395 			vtnet_init_locked(sc, 0);
1396 		} else if (update)
1397 			vtnet_update_rx_offloads(sc);
1398 	}
1399 
1400 	return (0);
1401 }
1402 
1403 static int
1404 vtnet_ioctl(if_t ifp, u_long cmd, caddr_t data)
1405 {
1406 	struct vtnet_softc *sc;
1407 	struct ifreq *ifr;
1408 	int error;
1409 
1410 	sc = if_getsoftc(ifp);
1411 	ifr = (struct ifreq *) data;
1412 	error = 0;
1413 
1414 	switch (cmd) {
1415 	case SIOCSIFMTU:
1416 		VTNET_CORE_LOCK(sc);
1417 		error = vtnet_ioctl_mtu(sc, ifr->ifr_mtu);
1418 		VTNET_CORE_UNLOCK(sc);
1419 		break;
1420 
1421 	case SIOCSIFFLAGS:
1422 		VTNET_CORE_LOCK(sc);
1423 		error = vtnet_ioctl_ifflags(sc);
1424 		VTNET_CORE_UNLOCK(sc);
1425 		break;
1426 
1427 	case SIOCADDMULTI:
1428 	case SIOCDELMULTI:
1429 		VTNET_CORE_LOCK(sc);
1430 		error = vtnet_ioctl_multi(sc);
1431 		VTNET_CORE_UNLOCK(sc);
1432 		break;
1433 
1434 	case SIOCSIFMEDIA:
1435 	case SIOCGIFMEDIA:
1436 		error = ifmedia_ioctl(ifp, ifr, &sc->vtnet_media, cmd);
1437 		break;
1438 
1439 	case SIOCSIFCAP:
1440 		VTNET_CORE_LOCK(sc);
1441 		error = vtnet_ioctl_ifcap(sc, ifr);
1442 		VTNET_CORE_UNLOCK(sc);
1443 		VLAN_CAPABILITIES(ifp);
1444 		break;
1445 
1446 	default:
1447 		error = ether_ioctl(ifp, cmd, data);
1448 		break;
1449 	}
1450 
1451 	VTNET_CORE_LOCK_ASSERT_NOTOWNED(sc);
1452 
1453 	return (error);
1454 }
1455 
1456 static int
1457 vtnet_rxq_populate(struct vtnet_rxq *rxq)
1458 {
1459 	struct virtqueue *vq;
1460 	int nbufs, error;
1461 
1462 #ifdef DEV_NETMAP
1463 	error = vtnet_netmap_rxq_populate(rxq);
1464 	if (error >= 0)
1465 		return (error);
1466 #endif  /* DEV_NETMAP */
1467 
1468 	vq = rxq->vtnrx_vq;
1469 	error = ENOSPC;
1470 
1471 	for (nbufs = 0; !virtqueue_full(vq); nbufs++) {
1472 		error = vtnet_rxq_new_buf(rxq);
1473 		if (error)
1474 			break;
1475 	}
1476 
1477 	if (nbufs > 0) {
1478 		virtqueue_notify(vq);
1479 		/*
1480 		 * EMSGSIZE signifies the virtqueue did not have enough
1481 		 * entries available to hold the last mbuf. This is not
1482 		 * an error.
1483 		 */
1484 		if (error == EMSGSIZE)
1485 			error = 0;
1486 	}
1487 
1488 	return (error);
1489 }
1490 
1491 static void
1492 vtnet_rxq_free_mbufs(struct vtnet_rxq *rxq)
1493 {
1494 	struct virtqueue *vq;
1495 	struct mbuf *m;
1496 	int last;
1497 #ifdef DEV_NETMAP
1498 	struct netmap_kring *kring = netmap_kring_on(NA(rxq->vtnrx_sc->vtnet_ifp),
1499 							rxq->vtnrx_id, NR_RX);
1500 #else  /* !DEV_NETMAP */
1501 	void *kring = NULL;
1502 #endif /* !DEV_NETMAP */
1503 
1504 	vq = rxq->vtnrx_vq;
1505 	last = 0;
1506 
1507 	while ((m = virtqueue_drain(vq, &last)) != NULL) {
1508 		if (kring == NULL)
1509 			m_freem(m);
1510 	}
1511 
1512 	KASSERT(virtqueue_empty(vq),
1513 	    ("%s: mbufs remaining in rx queue %p", __func__, rxq));
1514 }
1515 
1516 static struct mbuf *
1517 vtnet_rx_alloc_buf(struct vtnet_softc *sc, int nbufs, struct mbuf **m_tailp)
1518 {
1519 	struct mbuf *m_head, *m_tail, *m;
1520 	int i, size;
1521 
1522 	m_head = NULL;
1523 	size = sc->vtnet_rx_clustersz;
1524 
1525 	KASSERT(nbufs == 1 || sc->vtnet_flags & VTNET_FLAG_LRO_NOMRG,
1526 	    ("%s: mbuf %d chain requested without LRO_NOMRG", __func__, nbufs));
1527 
1528 	for (i = 0; i < nbufs; i++) {
1529 		m = m_getjcl(M_NOWAIT, MT_DATA, i == 0 ? M_PKTHDR : 0, size);
1530 		if (m == NULL) {
1531 			sc->vtnet_stats.mbuf_alloc_failed++;
1532 			m_freem(m_head);
1533 			return (NULL);
1534 		}
1535 
1536 		m->m_len = size;
1537 #ifndef __NO_STRICT_ALIGNMENT
1538 		/*
1539 		 * Need to offset the mbuf if the header we're going to add
1540 		 * will misalign.
1541 		 */
1542 		if (sc->vtnet_hdr_size % 4 == 0) {
1543 			m_adj(m, ETHER_ALIGN);
1544 		}
1545 #endif
1546 		if (m_head != NULL) {
1547 			m_tail->m_next = m;
1548 			m_tail = m;
1549 		} else
1550 			m_head = m_tail = m;
1551 	}
1552 
1553 	if (m_tailp != NULL)
1554 		*m_tailp = m_tail;
1555 
1556 	return (m_head);
1557 }
1558 
1559 /*
1560  * Slow path for when LRO without mergeable buffers is negotiated.
1561  */
1562 static int
1563 vtnet_rxq_replace_lro_nomrg_buf(struct vtnet_rxq *rxq, struct mbuf *m0,
1564     int len0)
1565 {
1566 	struct vtnet_softc *sc;
1567 	struct mbuf *m, *m_prev, *m_new, *m_tail;
1568 	int len, clustersz, nreplace, error;
1569 
1570 	sc = rxq->vtnrx_sc;
1571 	clustersz = sc->vtnet_rx_clustersz;
1572 #ifndef __NO_STRICT_ALIGNMENT
1573 	/*
1574 	 * Need to offset the mbuf if the header we're going to add will
1575 	 * misalign, account for that here.
1576 	 */
1577 	if (sc->vtnet_hdr_size % 4 == 0)
1578 		clustersz -= ETHER_ALIGN;
1579 #endif
1580 
1581 	m_prev = NULL;
1582 	m_tail = NULL;
1583 	nreplace = 0;
1584 
1585 	m = m0;
1586 	len = len0;
1587 
1588 	/*
1589 	 * Since these mbuf chains are so large, avoid allocating a complete
1590 	 * replacement when the received frame did not consume the entire
1591 	 * chain. Unused mbufs are moved to the tail of the replacement mbuf.
1592 	 */
1593 	while (len > 0) {
1594 		if (m == NULL) {
1595 			sc->vtnet_stats.rx_frame_too_large++;
1596 			return (EMSGSIZE);
1597 		}
1598 
1599 		/*
1600 		 * Every mbuf should have the expected cluster size since that
1601 		 * is also used to allocate the replacements.
1602 		 */
1603 		KASSERT(m->m_len == clustersz,
1604 		    ("%s: mbuf size %d not expected cluster size %d", __func__,
1605 		    m->m_len, clustersz));
1606 
1607 		m->m_len = MIN(m->m_len, len);
1608 		len -= m->m_len;
1609 
1610 		m_prev = m;
1611 		m = m->m_next;
1612 		nreplace++;
1613 	}
1614 
1615 	KASSERT(nreplace > 0 && nreplace <= sc->vtnet_rx_nmbufs,
1616 	    ("%s: invalid replacement mbuf count %d max %d", __func__,
1617 	    nreplace, sc->vtnet_rx_nmbufs));
1618 
1619 	m_new = vtnet_rx_alloc_buf(sc, nreplace, &m_tail);
1620 	if (m_new == NULL) {
1621 		m_prev->m_len = clustersz;
1622 		return (ENOBUFS);
1623 	}
1624 
1625 	/*
1626 	 * Move any unused mbufs from the received mbuf chain onto the
1627 	 * end of the replacement chain.
1628 	 */
1629 	if (m_prev->m_next != NULL) {
1630 		m_tail->m_next = m_prev->m_next;
1631 		m_prev->m_next = NULL;
1632 	}
1633 
1634 	error = vtnet_rxq_enqueue_buf(rxq, m_new);
1635 	if (error) {
1636 		/*
1637 		 * The replacement is suppose to be an copy of the one
1638 		 * dequeued so this is a very unexpected error.
1639 		 *
1640 		 * Restore the m0 chain to the original state if it was
1641 		 * modified so we can then discard it.
1642 		 */
1643 		if (m_tail->m_next != NULL) {
1644 			m_prev->m_next = m_tail->m_next;
1645 			m_tail->m_next = NULL;
1646 		}
1647 		m_prev->m_len = clustersz;
1648 		sc->vtnet_stats.rx_enq_replacement_failed++;
1649 		m_freem(m_new);
1650 	}
1651 
1652 	return (error);
1653 }
1654 
1655 static int
1656 vtnet_rxq_replace_buf(struct vtnet_rxq *rxq, struct mbuf *m, int len)
1657 {
1658 	struct vtnet_softc *sc;
1659 	struct mbuf *m_new;
1660 	int error;
1661 
1662 	sc = rxq->vtnrx_sc;
1663 
1664 	if (sc->vtnet_flags & VTNET_FLAG_LRO_NOMRG)
1665 		return (vtnet_rxq_replace_lro_nomrg_buf(rxq, m, len));
1666 
1667 	MPASS(m->m_next == NULL);
1668 	if (m->m_len < len)
1669 		return (EMSGSIZE);
1670 
1671 	m_new = vtnet_rx_alloc_buf(sc, 1, NULL);
1672 	if (m_new == NULL)
1673 		return (ENOBUFS);
1674 
1675 	error = vtnet_rxq_enqueue_buf(rxq, m_new);
1676 	if (error) {
1677 		sc->vtnet_stats.rx_enq_replacement_failed++;
1678 		m_freem(m_new);
1679 	} else
1680 		m->m_len = len;
1681 
1682 	return (error);
1683 }
1684 
1685 static int
1686 vtnet_rxq_enqueue_buf(struct vtnet_rxq *rxq, struct mbuf *m)
1687 {
1688 	struct vtnet_softc *sc;
1689 	struct sglist *sg;
1690 	int header_inlined, error;
1691 
1692 	sc = rxq->vtnrx_sc;
1693 	sg = rxq->vtnrx_sg;
1694 
1695 	KASSERT(m->m_next == NULL || sc->vtnet_flags & VTNET_FLAG_LRO_NOMRG,
1696 	    ("%s: mbuf chain without LRO_NOMRG", __func__));
1697 	VTNET_RXQ_LOCK_ASSERT(rxq);
1698 
1699 	sglist_reset(sg);
1700 	header_inlined = vtnet_modern(sc) ||
1701 	    (sc->vtnet_flags & VTNET_FLAG_MRG_RXBUFS) != 0; /* TODO: ANY_LAYOUT */
1702 
1703 	/*
1704 	 * Note: The mbuf has been already adjusted when we allocate it if we
1705 	 * have to do strict alignment.
1706 	 */
1707 	if (header_inlined)
1708 		error = sglist_append_mbuf(sg, m);
1709 	else {
1710 		struct vtnet_rx_header *rxhdr =
1711 		    mtod(m, struct vtnet_rx_header *);
1712 		MPASS(sc->vtnet_hdr_size == sizeof(struct virtio_net_hdr));
1713 
1714 		/* Append the header and remaining mbuf data. */
1715 		error = sglist_append(sg, &rxhdr->vrh_hdr, sc->vtnet_hdr_size);
1716 		if (error)
1717 			return (error);
1718 		error = sglist_append(sg, &rxhdr[1],
1719 		    m->m_len - sizeof(struct vtnet_rx_header));
1720 		if (error)
1721 			return (error);
1722 
1723 		if (m->m_next != NULL)
1724 			error = sglist_append_mbuf(sg, m->m_next);
1725 	}
1726 
1727 	if (error)
1728 		return (error);
1729 
1730 	return (virtqueue_enqueue(rxq->vtnrx_vq, m, sg, 0, sg->sg_nseg));
1731 }
1732 
1733 static int
1734 vtnet_rxq_new_buf(struct vtnet_rxq *rxq)
1735 {
1736 	struct vtnet_softc *sc;
1737 	struct mbuf *m;
1738 	int error;
1739 
1740 	sc = rxq->vtnrx_sc;
1741 
1742 	m = vtnet_rx_alloc_buf(sc, sc->vtnet_rx_nmbufs, NULL);
1743 	if (m == NULL)
1744 		return (ENOBUFS);
1745 
1746 	error = vtnet_rxq_enqueue_buf(rxq, m);
1747 	if (error)
1748 		m_freem(m);
1749 
1750 	return (error);
1751 }
1752 
1753 static int
1754 vtnet_rxq_csum_needs_csum(struct vtnet_rxq *rxq, struct mbuf *m, uint16_t etype,
1755     int hoff, struct virtio_net_hdr *hdr)
1756 {
1757 	struct vtnet_softc *sc;
1758 	int error;
1759 
1760 	sc = rxq->vtnrx_sc;
1761 
1762 	/*
1763 	 * NEEDS_CSUM corresponds to Linux's CHECKSUM_PARTIAL, but FreeBSD does
1764 	 * not have an analogous CSUM flag. The checksum has been validated,
1765 	 * but is incomplete (TCP/UDP pseudo header).
1766 	 *
1767 	 * The packet is likely from another VM on the same host that itself
1768 	 * performed checksum offloading so Tx/Rx is basically a memcpy and
1769 	 * the checksum has little value.
1770 	 *
1771 	 * Default to receiving the packet as-is for performance reasons, but
1772 	 * this can cause issues if the packet is to be forwarded because it
1773 	 * does not contain a valid checksum. This patch may be helpful:
1774 	 * https://reviews.freebsd.org/D6611. In the meantime, have the driver
1775 	 * compute the checksum if requested.
1776 	 *
1777 	 * BMV: Need to add an CSUM_PARTIAL flag?
1778 	 */
1779 	if ((sc->vtnet_flags & VTNET_FLAG_FIXUP_NEEDS_CSUM) == 0) {
1780 		error = vtnet_rxq_csum_data_valid(rxq, m, etype, hoff, hdr);
1781 		return (error);
1782 	}
1783 
1784 	/*
1785 	 * Compute the checksum in the driver so the packet will contain a
1786 	 * valid checksum. The checksum is at csum_offset from csum_start.
1787 	 */
1788 	switch (etype) {
1789 #if defined(INET) || defined(INET6)
1790 	case ETHERTYPE_IP:
1791 	case ETHERTYPE_IPV6: {
1792 		int csum_off, csum_end;
1793 		uint16_t csum;
1794 
1795 		csum_off = hdr->csum_start + hdr->csum_offset;
1796 		csum_end = csum_off + sizeof(uint16_t);
1797 
1798 		/* Assume checksum will be in the first mbuf. */
1799 		if (m->m_len < csum_end || m->m_pkthdr.len < csum_end)
1800 			return (1);
1801 
1802 		/*
1803 		 * Like in_delayed_cksum()/in6_delayed_cksum(), compute the
1804 		 * checksum and write it at the specified offset. We could
1805 		 * try to verify the packet: csum_start should probably
1806 		 * correspond to the start of the TCP/UDP header.
1807 		 *
1808 		 * BMV: Need to properly handle UDP with zero checksum. Is
1809 		 * the IPv4 header checksum implicitly validated?
1810 		 */
1811 		csum = in_cksum_skip(m, m->m_pkthdr.len, hdr->csum_start);
1812 		*(uint16_t *)(mtodo(m, csum_off)) = csum;
1813 		m->m_pkthdr.csum_flags |= CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
1814 		m->m_pkthdr.csum_data = 0xFFFF;
1815 		break;
1816 	}
1817 #endif
1818 	default:
1819 		sc->vtnet_stats.rx_csum_bad_ethtype++;
1820 		return (1);
1821 	}
1822 
1823 	return (0);
1824 }
1825 
1826 static int
1827 vtnet_rxq_csum_data_valid(struct vtnet_rxq *rxq, struct mbuf *m,
1828     uint16_t etype, int hoff, struct virtio_net_hdr *hdr __unused)
1829 {
1830 #if 0
1831 	struct vtnet_softc *sc;
1832 #endif
1833 	int protocol;
1834 
1835 #if 0
1836 	sc = rxq->vtnrx_sc;
1837 #endif
1838 
1839 	switch (etype) {
1840 #if defined(INET)
1841 	case ETHERTYPE_IP:
1842 		if (__predict_false(m->m_len < hoff + sizeof(struct ip)))
1843 			protocol = IPPROTO_DONE;
1844 		else {
1845 			struct ip *ip = (struct ip *)(m->m_data + hoff);
1846 			protocol = ip->ip_p;
1847 		}
1848 		break;
1849 #endif
1850 #if defined(INET6)
1851 	case ETHERTYPE_IPV6:
1852 		if (__predict_false(m->m_len < hoff + sizeof(struct ip6_hdr))
1853 		    || ip6_lasthdr(m, hoff, IPPROTO_IPV6, &protocol) < 0)
1854 			protocol = IPPROTO_DONE;
1855 		break;
1856 #endif
1857 	default:
1858 		protocol = IPPROTO_DONE;
1859 		break;
1860 	}
1861 
1862 	switch (protocol) {
1863 	case IPPROTO_TCP:
1864 	case IPPROTO_UDP:
1865 		m->m_pkthdr.csum_flags |= CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
1866 		m->m_pkthdr.csum_data = 0xFFFF;
1867 		break;
1868 	default:
1869 		/*
1870 		 * FreeBSD does not support checksum offloading of this
1871 		 * protocol. Let the stack re-verify the checksum later
1872 		 * if the protocol is supported.
1873 		 */
1874 #if 0
1875 		if_printf(sc->vtnet_ifp,
1876 		    "%s: checksum offload of unsupported protocol "
1877 		    "etype=%#x protocol=%d csum_start=%d csum_offset=%d\n",
1878 		    __func__, etype, protocol, hdr->csum_start,
1879 		    hdr->csum_offset);
1880 #endif
1881 		break;
1882 	}
1883 
1884 	return (0);
1885 }
1886 
1887 static int
1888 vtnet_rxq_csum(struct vtnet_rxq *rxq, struct mbuf *m,
1889     struct virtio_net_hdr *hdr)
1890 {
1891 	const struct ether_header *eh;
1892 	int hoff;
1893 	uint16_t etype;
1894 
1895 	eh = mtod(m, const struct ether_header *);
1896 	etype = ntohs(eh->ether_type);
1897 	if (etype == ETHERTYPE_VLAN) {
1898 		/* TODO BMV: Handle QinQ. */
1899 		const struct ether_vlan_header *evh =
1900 		    mtod(m, const struct ether_vlan_header *);
1901 		etype = ntohs(evh->evl_proto);
1902 		hoff = sizeof(struct ether_vlan_header);
1903 	} else
1904 		hoff = sizeof(struct ether_header);
1905 
1906 	if (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM)
1907 		return (vtnet_rxq_csum_needs_csum(rxq, m, etype, hoff, hdr));
1908 	else /* VIRTIO_NET_HDR_F_DATA_VALID */
1909 		return (vtnet_rxq_csum_data_valid(rxq, m, etype, hoff, hdr));
1910 }
1911 
1912 static void
1913 vtnet_rxq_discard_merged_bufs(struct vtnet_rxq *rxq, int nbufs)
1914 {
1915 	struct mbuf *m;
1916 
1917 	while (--nbufs > 0) {
1918 		m = virtqueue_dequeue(rxq->vtnrx_vq, NULL);
1919 		if (m == NULL)
1920 			break;
1921 		vtnet_rxq_discard_buf(rxq, m);
1922 	}
1923 }
1924 
1925 static void
1926 vtnet_rxq_discard_buf(struct vtnet_rxq *rxq, struct mbuf *m)
1927 {
1928 	int error __diagused;
1929 
1930 	/*
1931 	 * Requeue the discarded mbuf. This should always be successful
1932 	 * since it was just dequeued.
1933 	 */
1934 	error = vtnet_rxq_enqueue_buf(rxq, m);
1935 	KASSERT(error == 0,
1936 	    ("%s: cannot requeue discarded mbuf %d", __func__, error));
1937 }
1938 
1939 static int
1940 vtnet_rxq_merged_eof(struct vtnet_rxq *rxq, struct mbuf *m_head, int nbufs)
1941 {
1942 	struct vtnet_softc *sc;
1943 	struct virtqueue *vq;
1944 	struct mbuf *m_tail;
1945 
1946 	sc = rxq->vtnrx_sc;
1947 	vq = rxq->vtnrx_vq;
1948 	m_tail = m_head;
1949 
1950 	while (--nbufs > 0) {
1951 		struct mbuf *m;
1952 		uint32_t len;
1953 
1954 		m = virtqueue_dequeue(vq, &len);
1955 		if (m == NULL) {
1956 			rxq->vtnrx_stats.vrxs_ierrors++;
1957 			goto fail;
1958 		}
1959 
1960 		if (vtnet_rxq_new_buf(rxq) != 0) {
1961 			rxq->vtnrx_stats.vrxs_iqdrops++;
1962 			vtnet_rxq_discard_buf(rxq, m);
1963 			if (nbufs > 1)
1964 				vtnet_rxq_discard_merged_bufs(rxq, nbufs);
1965 			goto fail;
1966 		}
1967 
1968 		if (m->m_len < len)
1969 			len = m->m_len;
1970 
1971 		m->m_len = len;
1972 		m->m_flags &= ~M_PKTHDR;
1973 
1974 		m_head->m_pkthdr.len += len;
1975 		m_tail->m_next = m;
1976 		m_tail = m;
1977 	}
1978 
1979 	return (0);
1980 
1981 fail:
1982 	sc->vtnet_stats.rx_mergeable_failed++;
1983 	m_freem(m_head);
1984 
1985 	return (1);
1986 }
1987 
1988 #if defined(INET) || defined(INET6)
1989 static int
1990 vtnet_lro_rx(struct vtnet_rxq *rxq, struct mbuf *m)
1991 {
1992 	struct lro_ctrl *lro;
1993 
1994 	lro = &rxq->vtnrx_lro;
1995 
1996 	if (lro->lro_mbuf_max != 0) {
1997 		tcp_lro_queue_mbuf(lro, m);
1998 		return (0);
1999 	}
2000 
2001 	return (tcp_lro_rx(lro, m, 0));
2002 }
2003 #endif
2004 
2005 static void
2006 vtnet_rxq_input(struct vtnet_rxq *rxq, struct mbuf *m,
2007     struct virtio_net_hdr *hdr)
2008 {
2009 	struct vtnet_softc *sc;
2010 	if_t ifp;
2011 
2012 	sc = rxq->vtnrx_sc;
2013 	ifp = sc->vtnet_ifp;
2014 
2015 	if (if_getcapenable(ifp) & IFCAP_VLAN_HWTAGGING) {
2016 		struct ether_header *eh = mtod(m, struct ether_header *);
2017 		if (eh->ether_type == htons(ETHERTYPE_VLAN)) {
2018 			vtnet_vlan_tag_remove(m);
2019 			/*
2020 			 * With the 802.1Q header removed, update the
2021 			 * checksum starting location accordingly.
2022 			 */
2023 			if (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM)
2024 				hdr->csum_start -= ETHER_VLAN_ENCAP_LEN;
2025 		}
2026 	}
2027 
2028 	m->m_pkthdr.flowid = rxq->vtnrx_id;
2029 	M_HASHTYPE_SET(m, M_HASHTYPE_OPAQUE);
2030 
2031 	if (hdr->flags &
2032 	    (VIRTIO_NET_HDR_F_NEEDS_CSUM | VIRTIO_NET_HDR_F_DATA_VALID)) {
2033 		if (vtnet_rxq_csum(rxq, m, hdr) == 0)
2034 			rxq->vtnrx_stats.vrxs_csum++;
2035 		else
2036 			rxq->vtnrx_stats.vrxs_csum_failed++;
2037 	}
2038 
2039 	if (hdr->gso_size != 0) {
2040 		switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
2041 		case VIRTIO_NET_HDR_GSO_TCPV4:
2042 		case VIRTIO_NET_HDR_GSO_TCPV6:
2043 			m->m_pkthdr.lro_nsegs =
2044 			    howmany(m->m_pkthdr.len, hdr->gso_size);
2045 			rxq->vtnrx_stats.vrxs_host_lro++;
2046 			break;
2047 		}
2048 	}
2049 
2050 	rxq->vtnrx_stats.vrxs_ipackets++;
2051 	rxq->vtnrx_stats.vrxs_ibytes += m->m_pkthdr.len;
2052 
2053 #if defined(INET) || defined(INET6)
2054 	if (vtnet_software_lro(sc) && if_getcapenable(ifp) & IFCAP_LRO) {
2055 		if (vtnet_lro_rx(rxq, m) == 0)
2056 			return;
2057 	}
2058 #endif
2059 
2060 	if_input(ifp, m);
2061 }
2062 
2063 static int
2064 vtnet_rxq_eof(struct vtnet_rxq *rxq)
2065 {
2066 	struct virtio_net_hdr lhdr, *hdr;
2067 	struct vtnet_softc *sc;
2068 	if_t ifp;
2069 	struct virtqueue *vq;
2070 	int deq, count;
2071 
2072 	sc = rxq->vtnrx_sc;
2073 	vq = rxq->vtnrx_vq;
2074 	ifp = sc->vtnet_ifp;
2075 	deq = 0;
2076 	count = sc->vtnet_rx_process_limit;
2077 
2078 	VTNET_RXQ_LOCK_ASSERT(rxq);
2079 
2080 	while (count-- > 0) {
2081 		struct mbuf *m;
2082 		uint32_t len, nbufs, adjsz;
2083 
2084 		m = virtqueue_dequeue(vq, &len);
2085 		if (m == NULL)
2086 			break;
2087 		deq++;
2088 
2089 		if (len < sc->vtnet_hdr_size + ETHER_HDR_LEN) {
2090 			rxq->vtnrx_stats.vrxs_ierrors++;
2091 			vtnet_rxq_discard_buf(rxq, m);
2092 			continue;
2093 		}
2094 
2095 		if (sc->vtnet_flags & VTNET_FLAG_MRG_RXBUFS) {
2096 			struct virtio_net_hdr_mrg_rxbuf *mhdr =
2097 			    mtod(m, struct virtio_net_hdr_mrg_rxbuf *);
2098 			kmsan_mark(mhdr, sizeof(*mhdr), KMSAN_STATE_INITED);
2099 			nbufs = vtnet_htog16(sc, mhdr->num_buffers);
2100 			adjsz = sizeof(struct virtio_net_hdr_mrg_rxbuf);
2101 		} else if (vtnet_modern(sc)) {
2102 			nbufs = 1; /* num_buffers is always 1 */
2103 			adjsz = sizeof(struct virtio_net_hdr_v1);
2104 		} else {
2105 			nbufs = 1;
2106 			adjsz = sizeof(struct vtnet_rx_header);
2107 			/*
2108 			 * Account for our gap between the header and start of
2109 			 * data to keep the segments separated.
2110 			 */
2111 			len += VTNET_RX_HEADER_PAD;
2112 		}
2113 
2114 		if (vtnet_rxq_replace_buf(rxq, m, len) != 0) {
2115 			rxq->vtnrx_stats.vrxs_iqdrops++;
2116 			vtnet_rxq_discard_buf(rxq, m);
2117 			if (nbufs > 1)
2118 				vtnet_rxq_discard_merged_bufs(rxq, nbufs);
2119 			continue;
2120 		}
2121 
2122 		m->m_pkthdr.len = len;
2123 		m->m_pkthdr.rcvif = ifp;
2124 		m->m_pkthdr.csum_flags = 0;
2125 
2126 		if (nbufs > 1) {
2127 			/* Dequeue the rest of chain. */
2128 			if (vtnet_rxq_merged_eof(rxq, m, nbufs) != 0)
2129 				continue;
2130 		}
2131 
2132 		kmsan_mark_mbuf(m, KMSAN_STATE_INITED);
2133 
2134 		/*
2135 		 * Save an endian swapped version of the header prior to it
2136 		 * being stripped. The header is always at the start of the
2137 		 * mbuf data. num_buffers was already saved (and not needed)
2138 		 * so use the standard header.
2139 		 */
2140 		hdr = mtod(m, struct virtio_net_hdr *);
2141 		lhdr.flags = hdr->flags;
2142 		lhdr.gso_type = hdr->gso_type;
2143 		lhdr.hdr_len = vtnet_htog16(sc, hdr->hdr_len);
2144 		lhdr.gso_size = vtnet_htog16(sc, hdr->gso_size);
2145 		lhdr.csum_start = vtnet_htog16(sc, hdr->csum_start);
2146 		lhdr.csum_offset = vtnet_htog16(sc, hdr->csum_offset);
2147 		m_adj(m, adjsz);
2148 
2149 		if (PFIL_HOOKED_IN(sc->vtnet_pfil)) {
2150 			pfil_return_t pfil;
2151 
2152 			pfil = pfil_mbuf_in(sc->vtnet_pfil, &m, ifp, NULL);
2153 			switch (pfil) {
2154 			case PFIL_DROPPED:
2155 			case PFIL_CONSUMED:
2156 				continue;
2157 			default:
2158 				KASSERT(pfil == PFIL_PASS,
2159 				    ("Filter returned %d!", pfil));
2160 			}
2161 		}
2162 
2163 		vtnet_rxq_input(rxq, m, &lhdr);
2164 	}
2165 
2166 	if (deq > 0) {
2167 #if defined(INET) || defined(INET6)
2168 		if (vtnet_software_lro(sc))
2169 			tcp_lro_flush_all(&rxq->vtnrx_lro);
2170 #endif
2171 		virtqueue_notify(vq);
2172 	}
2173 
2174 	return (count > 0 ? 0 : EAGAIN);
2175 }
2176 
2177 static void
2178 vtnet_rx_vq_process(struct vtnet_rxq *rxq, int tries)
2179 {
2180 	struct vtnet_softc *sc;
2181 	if_t ifp;
2182 	u_int more;
2183 #ifdef DEV_NETMAP
2184 	int nmirq;
2185 #endif /* DEV_NETMAP */
2186 
2187 	sc = rxq->vtnrx_sc;
2188 	ifp = sc->vtnet_ifp;
2189 
2190 	if (__predict_false(rxq->vtnrx_id >= sc->vtnet_act_vq_pairs)) {
2191 		/*
2192 		 * Ignore this interrupt. Either this is a spurious interrupt
2193 		 * or multiqueue without per-VQ MSIX so every queue needs to
2194 		 * be polled (a brain dead configuration we could try harder
2195 		 * to avoid).
2196 		 */
2197 		vtnet_rxq_disable_intr(rxq);
2198 		return;
2199 	}
2200 
2201 	VTNET_RXQ_LOCK(rxq);
2202 
2203 #ifdef DEV_NETMAP
2204 	/*
2205 	 * We call netmap_rx_irq() under lock to prevent concurrent calls.
2206 	 * This is not necessary to serialize the access to the RX vq, but
2207 	 * rather to avoid races that may happen if this interface is
2208 	 * attached to a VALE switch, which would cause received packets
2209 	 * to stall in the RX queue (nm_kr_tryget() could find the kring
2210 	 * busy when called from netmap_bwrap_intr_notify()).
2211 	 */
2212 	nmirq = netmap_rx_irq(ifp, rxq->vtnrx_id, &more);
2213 	if (nmirq != NM_IRQ_PASS) {
2214 		VTNET_RXQ_UNLOCK(rxq);
2215 		if (nmirq == NM_IRQ_RESCHED) {
2216 			taskqueue_enqueue(rxq->vtnrx_tq, &rxq->vtnrx_intrtask);
2217 		}
2218 		return;
2219 	}
2220 #endif /* DEV_NETMAP */
2221 
2222 again:
2223 	if ((if_getdrvflags(ifp) & IFF_DRV_RUNNING) == 0) {
2224 		VTNET_RXQ_UNLOCK(rxq);
2225 		return;
2226 	}
2227 
2228 	more = vtnet_rxq_eof(rxq);
2229 	if (more || vtnet_rxq_enable_intr(rxq) != 0) {
2230 		if (!more)
2231 			vtnet_rxq_disable_intr(rxq);
2232 		/*
2233 		 * This is an occasional condition or race (when !more),
2234 		 * so retry a few times before scheduling the taskqueue.
2235 		 */
2236 		if (tries-- > 0)
2237 			goto again;
2238 
2239 		rxq->vtnrx_stats.vrxs_rescheduled++;
2240 		VTNET_RXQ_UNLOCK(rxq);
2241 		taskqueue_enqueue(rxq->vtnrx_tq, &rxq->vtnrx_intrtask);
2242 	} else
2243 		VTNET_RXQ_UNLOCK(rxq);
2244 }
2245 
2246 static void
2247 vtnet_rx_vq_intr(void *xrxq)
2248 {
2249 	struct vtnet_rxq *rxq;
2250 
2251 	rxq = xrxq;
2252 	vtnet_rx_vq_process(rxq, VTNET_INTR_DISABLE_RETRIES);
2253 }
2254 
2255 static void
2256 vtnet_rxq_tq_intr(void *xrxq, int pending __unused)
2257 {
2258 	struct vtnet_rxq *rxq;
2259 
2260 	rxq = xrxq;
2261 	vtnet_rx_vq_process(rxq, 0);
2262 }
2263 
2264 static int
2265 vtnet_txq_intr_threshold(struct vtnet_txq *txq)
2266 {
2267 	struct vtnet_softc *sc;
2268 	int threshold;
2269 
2270 	sc = txq->vtntx_sc;
2271 
2272 	/*
2273 	 * The Tx interrupt is disabled until the queue free count falls
2274 	 * below our threshold. Completed frames are drained from the Tx
2275 	 * virtqueue before transmitting new frames and in the watchdog
2276 	 * callout, so the frequency of Tx interrupts is greatly reduced,
2277 	 * at the cost of not freeing mbufs as quickly as they otherwise
2278 	 * would be.
2279 	 */
2280 	threshold = virtqueue_size(txq->vtntx_vq) / 4;
2281 
2282 	/*
2283 	 * Without indirect descriptors, leave enough room for the most
2284 	 * segments we handle.
2285 	 */
2286 	if ((sc->vtnet_flags & VTNET_FLAG_INDIRECT) == 0 &&
2287 	    threshold < sc->vtnet_tx_nsegs)
2288 		threshold = sc->vtnet_tx_nsegs;
2289 
2290 	return (threshold);
2291 }
2292 
2293 static int
2294 vtnet_txq_below_threshold(struct vtnet_txq *txq)
2295 {
2296 	struct virtqueue *vq;
2297 
2298 	vq = txq->vtntx_vq;
2299 
2300 	return (virtqueue_nfree(vq) <= txq->vtntx_intr_threshold);
2301 }
2302 
2303 static int
2304 vtnet_txq_notify(struct vtnet_txq *txq)
2305 {
2306 	struct virtqueue *vq;
2307 
2308 	vq = txq->vtntx_vq;
2309 
2310 	txq->vtntx_watchdog = VTNET_TX_TIMEOUT;
2311 	virtqueue_notify(vq);
2312 
2313 	if (vtnet_txq_enable_intr(txq) == 0)
2314 		return (0);
2315 
2316 	/*
2317 	 * Drain frames that were completed since last checked. If this
2318 	 * causes the queue to go above the threshold, the caller should
2319 	 * continue transmitting.
2320 	 */
2321 	if (vtnet_txq_eof(txq) != 0 && vtnet_txq_below_threshold(txq) == 0) {
2322 		virtqueue_disable_intr(vq);
2323 		return (1);
2324 	}
2325 
2326 	return (0);
2327 }
2328 
2329 static void
2330 vtnet_txq_free_mbufs(struct vtnet_txq *txq)
2331 {
2332 	struct virtqueue *vq;
2333 	struct vtnet_tx_header *txhdr;
2334 	int last;
2335 #ifdef DEV_NETMAP
2336 	struct netmap_kring *kring = netmap_kring_on(NA(txq->vtntx_sc->vtnet_ifp),
2337 							txq->vtntx_id, NR_TX);
2338 #else  /* !DEV_NETMAP */
2339 	void *kring = NULL;
2340 #endif /* !DEV_NETMAP */
2341 
2342 	vq = txq->vtntx_vq;
2343 	last = 0;
2344 
2345 	while ((txhdr = virtqueue_drain(vq, &last)) != NULL) {
2346 		if (kring == NULL) {
2347 			m_freem(txhdr->vth_mbuf);
2348 			uma_zfree(vtnet_tx_header_zone, txhdr);
2349 		}
2350 	}
2351 
2352 	KASSERT(virtqueue_empty(vq),
2353 	    ("%s: mbufs remaining in tx queue %p", __func__, txq));
2354 }
2355 
2356 /*
2357  * BMV: This can go away once we finally have offsets in the mbuf header.
2358  */
2359 static int
2360 vtnet_txq_offload_ctx(struct vtnet_txq *txq, struct mbuf *m, int *etype,
2361     int *proto, int *start)
2362 {
2363 	struct vtnet_softc *sc;
2364 	struct ether_vlan_header *evh;
2365 #if defined(INET) || defined(INET6)
2366 	int offset;
2367 #endif
2368 
2369 	sc = txq->vtntx_sc;
2370 
2371 	evh = mtod(m, struct ether_vlan_header *);
2372 	if (evh->evl_encap_proto == htons(ETHERTYPE_VLAN)) {
2373 		/* BMV: We should handle nested VLAN tags too. */
2374 		*etype = ntohs(evh->evl_proto);
2375 #if defined(INET) || defined(INET6)
2376 		offset = sizeof(struct ether_vlan_header);
2377 #endif
2378 	} else {
2379 		*etype = ntohs(evh->evl_encap_proto);
2380 #if defined(INET) || defined(INET6)
2381 		offset = sizeof(struct ether_header);
2382 #endif
2383 	}
2384 
2385 	switch (*etype) {
2386 #if defined(INET)
2387 	case ETHERTYPE_IP: {
2388 		struct ip *ip, iphdr;
2389 		if (__predict_false(m->m_len < offset + sizeof(struct ip))) {
2390 			m_copydata(m, offset, sizeof(struct ip),
2391 			    (caddr_t) &iphdr);
2392 			ip = &iphdr;
2393 		} else
2394 			ip = (struct ip *)(m->m_data + offset);
2395 		*proto = ip->ip_p;
2396 		*start = offset + (ip->ip_hl << 2);
2397 		break;
2398 	}
2399 #endif
2400 #if defined(INET6)
2401 	case ETHERTYPE_IPV6:
2402 		*proto = -1;
2403 		*start = ip6_lasthdr(m, offset, IPPROTO_IPV6, proto);
2404 		/* Assert the network stack sent us a valid packet. */
2405 		KASSERT(*start > offset,
2406 		    ("%s: mbuf %p start %d offset %d proto %d", __func__, m,
2407 		    *start, offset, *proto));
2408 		break;
2409 #endif
2410 	default:
2411 		sc->vtnet_stats.tx_csum_unknown_ethtype++;
2412 		return (EINVAL);
2413 	}
2414 
2415 	return (0);
2416 }
2417 
2418 static int
2419 vtnet_txq_offload_tso(struct vtnet_txq *txq, struct mbuf *m, int eth_type,
2420     int offset, struct virtio_net_hdr *hdr)
2421 {
2422 	static struct timeval lastecn;
2423 	static int curecn;
2424 	struct vtnet_softc *sc;
2425 	struct tcphdr *tcp, tcphdr;
2426 
2427 	sc = txq->vtntx_sc;
2428 
2429 	if (__predict_false(m->m_len < offset + sizeof(struct tcphdr))) {
2430 		m_copydata(m, offset, sizeof(struct tcphdr), (caddr_t) &tcphdr);
2431 		tcp = &tcphdr;
2432 	} else
2433 		tcp = (struct tcphdr *)(m->m_data + offset);
2434 
2435 	hdr->hdr_len = vtnet_gtoh16(sc, offset + (tcp->th_off << 2));
2436 	hdr->gso_size = vtnet_gtoh16(sc, m->m_pkthdr.tso_segsz);
2437 	hdr->gso_type = eth_type == ETHERTYPE_IP ? VIRTIO_NET_HDR_GSO_TCPV4 :
2438 	    VIRTIO_NET_HDR_GSO_TCPV6;
2439 
2440 	if (__predict_false(tcp->th_flags & TH_CWR)) {
2441 		/*
2442 		 * Drop if VIRTIO_NET_F_HOST_ECN was not negotiated. In
2443 		 * FreeBSD, ECN support is not on a per-interface basis,
2444 		 * but globally via the net.inet.tcp.ecn.enable sysctl
2445 		 * knob. The default is off.
2446 		 */
2447 		if ((sc->vtnet_flags & VTNET_FLAG_TSO_ECN) == 0) {
2448 			if (ppsratecheck(&lastecn, &curecn, 1))
2449 				if_printf(sc->vtnet_ifp,
2450 				    "TSO with ECN not negotiated with host\n");
2451 			return (ENOTSUP);
2452 		}
2453 		hdr->gso_type |= VIRTIO_NET_HDR_GSO_ECN;
2454 	}
2455 
2456 	txq->vtntx_stats.vtxs_tso++;
2457 
2458 	return (0);
2459 }
2460 
2461 static struct mbuf *
2462 vtnet_txq_offload(struct vtnet_txq *txq, struct mbuf *m,
2463     struct virtio_net_hdr *hdr)
2464 {
2465 	struct vtnet_softc *sc;
2466 	int flags, etype, csum_start, proto, error;
2467 
2468 	sc = txq->vtntx_sc;
2469 	flags = m->m_pkthdr.csum_flags;
2470 
2471 	error = vtnet_txq_offload_ctx(txq, m, &etype, &proto, &csum_start);
2472 	if (error)
2473 		goto drop;
2474 
2475 	if (flags & (VTNET_CSUM_OFFLOAD | VTNET_CSUM_OFFLOAD_IPV6)) {
2476 		/* Sanity check the parsed mbuf matches the offload flags. */
2477 		if (__predict_false((flags & VTNET_CSUM_OFFLOAD &&
2478 		    etype != ETHERTYPE_IP) || (flags & VTNET_CSUM_OFFLOAD_IPV6
2479 		    && etype != ETHERTYPE_IPV6))) {
2480 			sc->vtnet_stats.tx_csum_proto_mismatch++;
2481 			goto drop;
2482 		}
2483 
2484 		hdr->flags |= VIRTIO_NET_HDR_F_NEEDS_CSUM;
2485 		hdr->csum_start = vtnet_gtoh16(sc, csum_start);
2486 		hdr->csum_offset = vtnet_gtoh16(sc, m->m_pkthdr.csum_data);
2487 		txq->vtntx_stats.vtxs_csum++;
2488 	}
2489 
2490 	if (flags & (CSUM_IP_TSO | CSUM_IP6_TSO)) {
2491 		/*
2492 		 * Sanity check the parsed mbuf IP protocol is TCP, and
2493 		 * VirtIO TSO reqires the checksum offloading above.
2494 		 */
2495 		if (__predict_false(proto != IPPROTO_TCP)) {
2496 			sc->vtnet_stats.tx_tso_not_tcp++;
2497 			goto drop;
2498 		} else if (__predict_false((hdr->flags &
2499 		    VIRTIO_NET_HDR_F_NEEDS_CSUM) == 0)) {
2500 			sc->vtnet_stats.tx_tso_without_csum++;
2501 			goto drop;
2502 		}
2503 
2504 		error = vtnet_txq_offload_tso(txq, m, etype, csum_start, hdr);
2505 		if (error)
2506 			goto drop;
2507 	}
2508 
2509 	return (m);
2510 
2511 drop:
2512 	m_freem(m);
2513 	return (NULL);
2514 }
2515 
2516 static int
2517 vtnet_txq_enqueue_buf(struct vtnet_txq *txq, struct mbuf **m_head,
2518     struct vtnet_tx_header *txhdr)
2519 {
2520 	struct vtnet_softc *sc;
2521 	struct virtqueue *vq;
2522 	struct sglist *sg;
2523 	struct mbuf *m;
2524 	int error;
2525 
2526 	sc = txq->vtntx_sc;
2527 	vq = txq->vtntx_vq;
2528 	sg = txq->vtntx_sg;
2529 	m = *m_head;
2530 
2531 	sglist_reset(sg);
2532 	error = sglist_append(sg, &txhdr->vth_uhdr, sc->vtnet_hdr_size);
2533 	if (error != 0 || sg->sg_nseg != 1) {
2534 		KASSERT(0, ("%s: cannot add header to sglist error %d nseg %d",
2535 		    __func__, error, sg->sg_nseg));
2536 		goto fail;
2537 	}
2538 
2539 	error = sglist_append_mbuf(sg, m);
2540 	if (error) {
2541 		m = m_defrag(m, M_NOWAIT);
2542 		if (m == NULL)
2543 			goto fail;
2544 
2545 		*m_head = m;
2546 		sc->vtnet_stats.tx_defragged++;
2547 
2548 		error = sglist_append_mbuf(sg, m);
2549 		if (error)
2550 			goto fail;
2551 	}
2552 
2553 	txhdr->vth_mbuf = m;
2554 	error = virtqueue_enqueue(vq, txhdr, sg, sg->sg_nseg, 0);
2555 
2556 	return (error);
2557 
2558 fail:
2559 	sc->vtnet_stats.tx_defrag_failed++;
2560 	m_freem(*m_head);
2561 	*m_head = NULL;
2562 
2563 	return (ENOBUFS);
2564 }
2565 
2566 static int
2567 vtnet_txq_encap(struct vtnet_txq *txq, struct mbuf **m_head, int flags)
2568 {
2569 	struct vtnet_tx_header *txhdr;
2570 	struct virtio_net_hdr *hdr;
2571 	struct mbuf *m;
2572 	int error;
2573 
2574 	m = *m_head;
2575 	M_ASSERTPKTHDR(m);
2576 
2577 	txhdr = uma_zalloc(vtnet_tx_header_zone, flags | M_ZERO);
2578 	if (txhdr == NULL) {
2579 		m_freem(m);
2580 		*m_head = NULL;
2581 		return (ENOMEM);
2582 	}
2583 
2584 	/*
2585 	 * Always use the non-mergeable header, regardless if mergable headers
2586 	 * were negotiated, because for transmit num_buffers is always zero.
2587 	 * The vtnet_hdr_size is used to enqueue the right header size segment.
2588 	 */
2589 	hdr = &txhdr->vth_uhdr.hdr;
2590 
2591 	if (m->m_flags & M_VLANTAG) {
2592 		m = ether_vlanencap(m, m->m_pkthdr.ether_vtag);
2593 		if ((*m_head = m) == NULL) {
2594 			error = ENOBUFS;
2595 			goto fail;
2596 		}
2597 		m->m_flags &= ~M_VLANTAG;
2598 	}
2599 
2600 	if (m->m_pkthdr.csum_flags & VTNET_CSUM_ALL_OFFLOAD) {
2601 		m = vtnet_txq_offload(txq, m, hdr);
2602 		if ((*m_head = m) == NULL) {
2603 			error = ENOBUFS;
2604 			goto fail;
2605 		}
2606 	}
2607 
2608 	error = vtnet_txq_enqueue_buf(txq, m_head, txhdr);
2609 fail:
2610 	if (error)
2611 		uma_zfree(vtnet_tx_header_zone, txhdr);
2612 
2613 	return (error);
2614 }
2615 
2616 #ifdef VTNET_LEGACY_TX
2617 
2618 static void
2619 vtnet_start_locked(struct vtnet_txq *txq, if_t ifp)
2620 {
2621 	struct vtnet_softc *sc;
2622 	struct virtqueue *vq;
2623 	struct mbuf *m0;
2624 	int tries, enq;
2625 
2626 	sc = txq->vtntx_sc;
2627 	vq = txq->vtntx_vq;
2628 	tries = 0;
2629 
2630 	VTNET_TXQ_LOCK_ASSERT(txq);
2631 
2632 	if ((if_getdrvflags(ifp) & IFF_DRV_RUNNING) == 0 ||
2633 	    sc->vtnet_link_active == 0)
2634 		return;
2635 
2636 	vtnet_txq_eof(txq);
2637 
2638 again:
2639 	enq = 0;
2640 
2641 	while (!if_sendq_empty(ifp)) {
2642 		if (virtqueue_full(vq))
2643 			break;
2644 
2645 		m0 = if_dequeue(ifp);
2646 		if (m0 == NULL)
2647 			break;
2648 
2649 		if (vtnet_txq_encap(txq, &m0, M_NOWAIT) != 0) {
2650 			if (m0 != NULL)
2651 				if_sendq_prepend(ifp, m0);
2652 			break;
2653 		}
2654 
2655 		enq++;
2656 		ETHER_BPF_MTAP(ifp, m0);
2657 	}
2658 
2659 	if (enq > 0 && vtnet_txq_notify(txq) != 0) {
2660 		if (tries++ < VTNET_NOTIFY_RETRIES)
2661 			goto again;
2662 
2663 		txq->vtntx_stats.vtxs_rescheduled++;
2664 		taskqueue_enqueue(txq->vtntx_tq, &txq->vtntx_intrtask);
2665 	}
2666 }
2667 
2668 static void
2669 vtnet_start(if_t ifp)
2670 {
2671 	struct vtnet_softc *sc;
2672 	struct vtnet_txq *txq;
2673 
2674 	sc = if_getsoftc(ifp);
2675 	txq = &sc->vtnet_txqs[0];
2676 
2677 	VTNET_TXQ_LOCK(txq);
2678 	vtnet_start_locked(txq, ifp);
2679 	VTNET_TXQ_UNLOCK(txq);
2680 }
2681 
2682 #else /* !VTNET_LEGACY_TX */
2683 
2684 static int
2685 vtnet_txq_mq_start_locked(struct vtnet_txq *txq, struct mbuf *m)
2686 {
2687 	struct vtnet_softc *sc;
2688 	struct virtqueue *vq;
2689 	struct buf_ring *br;
2690 	if_t ifp;
2691 	int enq, tries, error;
2692 
2693 	sc = txq->vtntx_sc;
2694 	vq = txq->vtntx_vq;
2695 	br = txq->vtntx_br;
2696 	ifp = sc->vtnet_ifp;
2697 	tries = 0;
2698 	error = 0;
2699 
2700 	VTNET_TXQ_LOCK_ASSERT(txq);
2701 
2702 	if ((if_getdrvflags(ifp) & IFF_DRV_RUNNING) == 0 ||
2703 	    sc->vtnet_link_active == 0) {
2704 		if (m != NULL)
2705 			error = drbr_enqueue(ifp, br, m);
2706 		return (error);
2707 	}
2708 
2709 	if (m != NULL) {
2710 		error = drbr_enqueue(ifp, br, m);
2711 		if (error)
2712 			return (error);
2713 	}
2714 
2715 	vtnet_txq_eof(txq);
2716 
2717 again:
2718 	enq = 0;
2719 
2720 	while ((m = drbr_peek(ifp, br)) != NULL) {
2721 		if (virtqueue_full(vq)) {
2722 			drbr_putback(ifp, br, m);
2723 			break;
2724 		}
2725 
2726 		if (vtnet_txq_encap(txq, &m, M_NOWAIT) != 0) {
2727 			if (m != NULL)
2728 				drbr_putback(ifp, br, m);
2729 			else
2730 				drbr_advance(ifp, br);
2731 			break;
2732 		}
2733 		drbr_advance(ifp, br);
2734 
2735 		enq++;
2736 		ETHER_BPF_MTAP(ifp, m);
2737 	}
2738 
2739 	if (enq > 0 && vtnet_txq_notify(txq) != 0) {
2740 		if (tries++ < VTNET_NOTIFY_RETRIES)
2741 			goto again;
2742 
2743 		txq->vtntx_stats.vtxs_rescheduled++;
2744 		taskqueue_enqueue(txq->vtntx_tq, &txq->vtntx_intrtask);
2745 	}
2746 
2747 	return (0);
2748 }
2749 
2750 static int
2751 vtnet_txq_mq_start(if_t ifp, struct mbuf *m)
2752 {
2753 	struct vtnet_softc *sc;
2754 	struct vtnet_txq *txq;
2755 	int i, npairs, error;
2756 
2757 	sc = if_getsoftc(ifp);
2758 	npairs = sc->vtnet_act_vq_pairs;
2759 
2760 	if (M_HASHTYPE_GET(m) != M_HASHTYPE_NONE)
2761 		i = m->m_pkthdr.flowid % npairs;
2762 	else
2763 		i = curcpu % npairs;
2764 
2765 	txq = &sc->vtnet_txqs[i];
2766 
2767 	if (VTNET_TXQ_TRYLOCK(txq) != 0) {
2768 		error = vtnet_txq_mq_start_locked(txq, m);
2769 		VTNET_TXQ_UNLOCK(txq);
2770 	} else {
2771 		error = drbr_enqueue(ifp, txq->vtntx_br, m);
2772 		taskqueue_enqueue(txq->vtntx_tq, &txq->vtntx_defrtask);
2773 	}
2774 
2775 	return (error);
2776 }
2777 
2778 static void
2779 vtnet_txq_tq_deferred(void *xtxq, int pending __unused)
2780 {
2781 	struct vtnet_softc *sc;
2782 	struct vtnet_txq *txq;
2783 
2784 	txq = xtxq;
2785 	sc = txq->vtntx_sc;
2786 
2787 	VTNET_TXQ_LOCK(txq);
2788 	if (!drbr_empty(sc->vtnet_ifp, txq->vtntx_br))
2789 		vtnet_txq_mq_start_locked(txq, NULL);
2790 	VTNET_TXQ_UNLOCK(txq);
2791 }
2792 
2793 #endif /* VTNET_LEGACY_TX */
2794 
2795 static void
2796 vtnet_txq_start(struct vtnet_txq *txq)
2797 {
2798 	struct vtnet_softc *sc;
2799 	if_t ifp;
2800 
2801 	sc = txq->vtntx_sc;
2802 	ifp = sc->vtnet_ifp;
2803 
2804 #ifdef VTNET_LEGACY_TX
2805 	if (!if_sendq_empty(ifp))
2806 		vtnet_start_locked(txq, ifp);
2807 #else
2808 	if (!drbr_empty(ifp, txq->vtntx_br))
2809 		vtnet_txq_mq_start_locked(txq, NULL);
2810 #endif
2811 }
2812 
2813 static void
2814 vtnet_txq_tq_intr(void *xtxq, int pending __unused)
2815 {
2816 	struct vtnet_softc *sc;
2817 	struct vtnet_txq *txq;
2818 	if_t ifp;
2819 
2820 	txq = xtxq;
2821 	sc = txq->vtntx_sc;
2822 	ifp = sc->vtnet_ifp;
2823 
2824 	VTNET_TXQ_LOCK(txq);
2825 
2826 	if ((if_getdrvflags(ifp) & IFF_DRV_RUNNING) == 0) {
2827 		VTNET_TXQ_UNLOCK(txq);
2828 		return;
2829 	}
2830 
2831 	vtnet_txq_eof(txq);
2832 	vtnet_txq_start(txq);
2833 
2834 	VTNET_TXQ_UNLOCK(txq);
2835 }
2836 
2837 static int
2838 vtnet_txq_eof(struct vtnet_txq *txq)
2839 {
2840 	struct virtqueue *vq;
2841 	struct vtnet_tx_header *txhdr;
2842 	struct mbuf *m;
2843 	int deq;
2844 
2845 	vq = txq->vtntx_vq;
2846 	deq = 0;
2847 	VTNET_TXQ_LOCK_ASSERT(txq);
2848 
2849 	while ((txhdr = virtqueue_dequeue(vq, NULL)) != NULL) {
2850 		m = txhdr->vth_mbuf;
2851 		deq++;
2852 
2853 		txq->vtntx_stats.vtxs_opackets++;
2854 		txq->vtntx_stats.vtxs_obytes += m->m_pkthdr.len;
2855 		if (m->m_flags & M_MCAST)
2856 			txq->vtntx_stats.vtxs_omcasts++;
2857 
2858 		m_freem(m);
2859 		uma_zfree(vtnet_tx_header_zone, txhdr);
2860 	}
2861 
2862 	if (virtqueue_empty(vq))
2863 		txq->vtntx_watchdog = 0;
2864 
2865 	return (deq);
2866 }
2867 
2868 static void
2869 vtnet_tx_vq_intr(void *xtxq)
2870 {
2871 	struct vtnet_softc *sc;
2872 	struct vtnet_txq *txq;
2873 	if_t ifp;
2874 
2875 	txq = xtxq;
2876 	sc = txq->vtntx_sc;
2877 	ifp = sc->vtnet_ifp;
2878 
2879 	if (__predict_false(txq->vtntx_id >= sc->vtnet_act_vq_pairs)) {
2880 		/*
2881 		 * Ignore this interrupt. Either this is a spurious interrupt
2882 		 * or multiqueue without per-VQ MSIX so every queue needs to
2883 		 * be polled (a brain dead configuration we could try harder
2884 		 * to avoid).
2885 		 */
2886 		vtnet_txq_disable_intr(txq);
2887 		return;
2888 	}
2889 
2890 #ifdef DEV_NETMAP
2891 	if (netmap_tx_irq(ifp, txq->vtntx_id) != NM_IRQ_PASS)
2892 		return;
2893 #endif /* DEV_NETMAP */
2894 
2895 	VTNET_TXQ_LOCK(txq);
2896 
2897 	if ((if_getdrvflags(ifp) & IFF_DRV_RUNNING) == 0) {
2898 		VTNET_TXQ_UNLOCK(txq);
2899 		return;
2900 	}
2901 
2902 	vtnet_txq_eof(txq);
2903 	vtnet_txq_start(txq);
2904 
2905 	VTNET_TXQ_UNLOCK(txq);
2906 }
2907 
2908 static void
2909 vtnet_tx_start_all(struct vtnet_softc *sc)
2910 {
2911 	struct vtnet_txq *txq;
2912 	int i;
2913 
2914 	VTNET_CORE_LOCK_ASSERT(sc);
2915 
2916 	for (i = 0; i < sc->vtnet_act_vq_pairs; i++) {
2917 		txq = &sc->vtnet_txqs[i];
2918 
2919 		VTNET_TXQ_LOCK(txq);
2920 		vtnet_txq_start(txq);
2921 		VTNET_TXQ_UNLOCK(txq);
2922 	}
2923 }
2924 
2925 #ifndef VTNET_LEGACY_TX
2926 static void
2927 vtnet_qflush(if_t ifp)
2928 {
2929 	struct vtnet_softc *sc;
2930 	struct vtnet_txq *txq;
2931 	struct mbuf *m;
2932 	int i;
2933 
2934 	sc = if_getsoftc(ifp);
2935 
2936 	for (i = 0; i < sc->vtnet_act_vq_pairs; i++) {
2937 		txq = &sc->vtnet_txqs[i];
2938 
2939 		VTNET_TXQ_LOCK(txq);
2940 		while ((m = buf_ring_dequeue_sc(txq->vtntx_br)) != NULL)
2941 			m_freem(m);
2942 		VTNET_TXQ_UNLOCK(txq);
2943 	}
2944 
2945 	if_qflush(ifp);
2946 }
2947 #endif
2948 
2949 static int
2950 vtnet_watchdog(struct vtnet_txq *txq)
2951 {
2952 	if_t ifp;
2953 
2954 	ifp = txq->vtntx_sc->vtnet_ifp;
2955 
2956 	VTNET_TXQ_LOCK(txq);
2957 	if (txq->vtntx_watchdog == 1) {
2958 		/*
2959 		 * Only drain completed frames if the watchdog is about to
2960 		 * expire. If any frames were drained, there may be enough
2961 		 * free descriptors now available to transmit queued frames.
2962 		 * In that case, the timer will immediately be decremented
2963 		 * below, but the timeout is generous enough that should not
2964 		 * be a problem.
2965 		 */
2966 		if (vtnet_txq_eof(txq) != 0)
2967 			vtnet_txq_start(txq);
2968 	}
2969 
2970 	if (txq->vtntx_watchdog == 0 || --txq->vtntx_watchdog) {
2971 		VTNET_TXQ_UNLOCK(txq);
2972 		return (0);
2973 	}
2974 	VTNET_TXQ_UNLOCK(txq);
2975 
2976 	if_printf(ifp, "watchdog timeout on queue %d\n", txq->vtntx_id);
2977 	return (1);
2978 }
2979 
2980 static void
2981 vtnet_accum_stats(struct vtnet_softc *sc, struct vtnet_rxq_stats *rxacc,
2982     struct vtnet_txq_stats *txacc)
2983 {
2984 
2985 	bzero(rxacc, sizeof(struct vtnet_rxq_stats));
2986 	bzero(txacc, sizeof(struct vtnet_txq_stats));
2987 
2988 	for (int i = 0; i < sc->vtnet_max_vq_pairs; i++) {
2989 		struct vtnet_rxq_stats *rxst;
2990 		struct vtnet_txq_stats *txst;
2991 
2992 		rxst = &sc->vtnet_rxqs[i].vtnrx_stats;
2993 		rxacc->vrxs_ipackets += rxst->vrxs_ipackets;
2994 		rxacc->vrxs_ibytes += rxst->vrxs_ibytes;
2995 		rxacc->vrxs_iqdrops += rxst->vrxs_iqdrops;
2996 		rxacc->vrxs_csum += rxst->vrxs_csum;
2997 		rxacc->vrxs_csum_failed += rxst->vrxs_csum_failed;
2998 		rxacc->vrxs_rescheduled += rxst->vrxs_rescheduled;
2999 
3000 		txst = &sc->vtnet_txqs[i].vtntx_stats;
3001 		txacc->vtxs_opackets += txst->vtxs_opackets;
3002 		txacc->vtxs_obytes += txst->vtxs_obytes;
3003 		txacc->vtxs_csum += txst->vtxs_csum;
3004 		txacc->vtxs_tso += txst->vtxs_tso;
3005 		txacc->vtxs_rescheduled += txst->vtxs_rescheduled;
3006 	}
3007 }
3008 
3009 static uint64_t
3010 vtnet_get_counter(if_t ifp, ift_counter cnt)
3011 {
3012 	struct vtnet_softc *sc;
3013 	struct vtnet_rxq_stats rxaccum;
3014 	struct vtnet_txq_stats txaccum;
3015 
3016 	sc = if_getsoftc(ifp);
3017 	vtnet_accum_stats(sc, &rxaccum, &txaccum);
3018 
3019 	switch (cnt) {
3020 	case IFCOUNTER_IPACKETS:
3021 		return (rxaccum.vrxs_ipackets);
3022 	case IFCOUNTER_IQDROPS:
3023 		return (rxaccum.vrxs_iqdrops);
3024 	case IFCOUNTER_IERRORS:
3025 		return (rxaccum.vrxs_ierrors);
3026 	case IFCOUNTER_OPACKETS:
3027 		return (txaccum.vtxs_opackets);
3028 #ifndef VTNET_LEGACY_TX
3029 	case IFCOUNTER_OBYTES:
3030 		return (txaccum.vtxs_obytes);
3031 	case IFCOUNTER_OMCASTS:
3032 		return (txaccum.vtxs_omcasts);
3033 #endif
3034 	default:
3035 		return (if_get_counter_default(ifp, cnt));
3036 	}
3037 }
3038 
3039 static void
3040 vtnet_tick(void *xsc)
3041 {
3042 	struct vtnet_softc *sc;
3043 	if_t ifp;
3044 	int i, timedout;
3045 
3046 	sc = xsc;
3047 	ifp = sc->vtnet_ifp;
3048 	timedout = 0;
3049 
3050 	VTNET_CORE_LOCK_ASSERT(sc);
3051 
3052 	for (i = 0; i < sc->vtnet_act_vq_pairs; i++)
3053 		timedout |= vtnet_watchdog(&sc->vtnet_txqs[i]);
3054 
3055 	if (timedout != 0) {
3056 		if_setdrvflagbits(ifp, 0, IFF_DRV_RUNNING);
3057 		vtnet_init_locked(sc, 0);
3058 	} else
3059 		callout_schedule(&sc->vtnet_tick_ch, hz);
3060 }
3061 
3062 static void
3063 vtnet_start_taskqueues(struct vtnet_softc *sc)
3064 {
3065 	device_t dev;
3066 	struct vtnet_rxq *rxq;
3067 	struct vtnet_txq *txq;
3068 	int i, error;
3069 
3070 	dev = sc->vtnet_dev;
3071 
3072 	/*
3073 	 * Errors here are very difficult to recover from - we cannot
3074 	 * easily fail because, if this is during boot, we will hang
3075 	 * when freeing any successfully started taskqueues because
3076 	 * the scheduler isn't up yet.
3077 	 *
3078 	 * Most drivers just ignore the return value - it only fails
3079 	 * with ENOMEM so an error is not likely.
3080 	 */
3081 	for (i = 0; i < sc->vtnet_req_vq_pairs; i++) {
3082 		rxq = &sc->vtnet_rxqs[i];
3083 		error = taskqueue_start_threads(&rxq->vtnrx_tq, 1, PI_NET,
3084 		    "%s rxq %d", device_get_nameunit(dev), rxq->vtnrx_id);
3085 		if (error) {
3086 			device_printf(dev, "failed to start rx taskq %d\n",
3087 			    rxq->vtnrx_id);
3088 		}
3089 
3090 		txq = &sc->vtnet_txqs[i];
3091 		error = taskqueue_start_threads(&txq->vtntx_tq, 1, PI_NET,
3092 		    "%s txq %d", device_get_nameunit(dev), txq->vtntx_id);
3093 		if (error) {
3094 			device_printf(dev, "failed to start tx taskq %d\n",
3095 			    txq->vtntx_id);
3096 		}
3097 	}
3098 }
3099 
3100 static void
3101 vtnet_free_taskqueues(struct vtnet_softc *sc)
3102 {
3103 	struct vtnet_rxq *rxq;
3104 	struct vtnet_txq *txq;
3105 	int i;
3106 
3107 	for (i = 0; i < sc->vtnet_max_vq_pairs; i++) {
3108 		rxq = &sc->vtnet_rxqs[i];
3109 		if (rxq->vtnrx_tq != NULL) {
3110 			taskqueue_free(rxq->vtnrx_tq);
3111 			rxq->vtnrx_tq = NULL;
3112 		}
3113 
3114 		txq = &sc->vtnet_txqs[i];
3115 		if (txq->vtntx_tq != NULL) {
3116 			taskqueue_free(txq->vtntx_tq);
3117 			txq->vtntx_tq = NULL;
3118 		}
3119 	}
3120 }
3121 
3122 static void
3123 vtnet_drain_taskqueues(struct vtnet_softc *sc)
3124 {
3125 	struct vtnet_rxq *rxq;
3126 	struct vtnet_txq *txq;
3127 	int i;
3128 
3129 	for (i = 0; i < sc->vtnet_max_vq_pairs; i++) {
3130 		rxq = &sc->vtnet_rxqs[i];
3131 		if (rxq->vtnrx_tq != NULL)
3132 			taskqueue_drain(rxq->vtnrx_tq, &rxq->vtnrx_intrtask);
3133 
3134 		txq = &sc->vtnet_txqs[i];
3135 		if (txq->vtntx_tq != NULL) {
3136 			taskqueue_drain(txq->vtntx_tq, &txq->vtntx_intrtask);
3137 #ifndef VTNET_LEGACY_TX
3138 			taskqueue_drain(txq->vtntx_tq, &txq->vtntx_defrtask);
3139 #endif
3140 		}
3141 	}
3142 }
3143 
3144 static void
3145 vtnet_drain_rxtx_queues(struct vtnet_softc *sc)
3146 {
3147 	struct vtnet_rxq *rxq;
3148 	struct vtnet_txq *txq;
3149 	int i;
3150 
3151 	for (i = 0; i < sc->vtnet_max_vq_pairs; i++) {
3152 		rxq = &sc->vtnet_rxqs[i];
3153 		vtnet_rxq_free_mbufs(rxq);
3154 
3155 		txq = &sc->vtnet_txqs[i];
3156 		vtnet_txq_free_mbufs(txq);
3157 	}
3158 }
3159 
3160 static void
3161 vtnet_stop_rendezvous(struct vtnet_softc *sc)
3162 {
3163 	struct vtnet_rxq *rxq;
3164 	struct vtnet_txq *txq;
3165 	int i;
3166 
3167 	VTNET_CORE_LOCK_ASSERT(sc);
3168 
3169 	/*
3170 	 * Lock and unlock the per-queue mutex so we known the stop
3171 	 * state is visible. Doing only the active queues should be
3172 	 * sufficient, but it does not cost much extra to do all the
3173 	 * queues.
3174 	 */
3175 	for (i = 0; i < sc->vtnet_max_vq_pairs; i++) {
3176 		rxq = &sc->vtnet_rxqs[i];
3177 		VTNET_RXQ_LOCK(rxq);
3178 		VTNET_RXQ_UNLOCK(rxq);
3179 
3180 		txq = &sc->vtnet_txqs[i];
3181 		VTNET_TXQ_LOCK(txq);
3182 		VTNET_TXQ_UNLOCK(txq);
3183 	}
3184 }
3185 
3186 static void
3187 vtnet_stop(struct vtnet_softc *sc)
3188 {
3189 	device_t dev;
3190 	if_t ifp;
3191 
3192 	dev = sc->vtnet_dev;
3193 	ifp = sc->vtnet_ifp;
3194 
3195 	VTNET_CORE_LOCK_ASSERT(sc);
3196 
3197 	if_setdrvflagbits(ifp, 0, IFF_DRV_RUNNING);
3198 	sc->vtnet_link_active = 0;
3199 	callout_stop(&sc->vtnet_tick_ch);
3200 
3201 	/* Only advisory. */
3202 	vtnet_disable_interrupts(sc);
3203 
3204 #ifdef DEV_NETMAP
3205 	/* Stop any pending txsync/rxsync and disable them. */
3206 	netmap_disable_all_rings(ifp);
3207 #endif /* DEV_NETMAP */
3208 
3209 	/*
3210 	 * Stop the host adapter. This resets it to the pre-initialized
3211 	 * state. It will not generate any interrupts until after it is
3212 	 * reinitialized.
3213 	 */
3214 	virtio_stop(dev);
3215 	vtnet_stop_rendezvous(sc);
3216 
3217 	vtnet_drain_rxtx_queues(sc);
3218 	sc->vtnet_act_vq_pairs = 1;
3219 }
3220 
3221 static int
3222 vtnet_virtio_reinit(struct vtnet_softc *sc)
3223 {
3224 	device_t dev;
3225 	if_t ifp;
3226 	uint64_t features;
3227 	int error;
3228 
3229 	dev = sc->vtnet_dev;
3230 	ifp = sc->vtnet_ifp;
3231 	features = sc->vtnet_negotiated_features;
3232 
3233 	/*
3234 	 * Re-negotiate with the host, removing any disabled receive
3235 	 * features. Transmit features are disabled only on our side
3236 	 * via if_capenable and if_hwassist.
3237 	 */
3238 
3239 	if ((if_getcapenable(ifp) & (IFCAP_RXCSUM | IFCAP_RXCSUM_IPV6)) == 0)
3240 		features &= ~(VIRTIO_NET_F_GUEST_CSUM | VTNET_LRO_FEATURES);
3241 
3242 	if ((if_getcapenable(ifp) & IFCAP_LRO) == 0)
3243 		features &= ~VTNET_LRO_FEATURES;
3244 
3245 	if ((if_getcapenable(ifp) & IFCAP_VLAN_HWFILTER) == 0)
3246 		features &= ~VIRTIO_NET_F_CTRL_VLAN;
3247 
3248 	error = virtio_reinit(dev, features);
3249 	if (error) {
3250 		device_printf(dev, "virtio reinit error %d\n", error);
3251 		return (error);
3252 	}
3253 
3254 	sc->vtnet_features = features;
3255 	virtio_reinit_complete(dev);
3256 
3257 	return (0);
3258 }
3259 
3260 static void
3261 vtnet_init_rx_filters(struct vtnet_softc *sc)
3262 {
3263 	if_t ifp;
3264 
3265 	ifp = sc->vtnet_ifp;
3266 
3267 	if (sc->vtnet_flags & VTNET_FLAG_CTRL_RX) {
3268 		vtnet_rx_filter(sc);
3269 		vtnet_rx_filter_mac(sc);
3270 	}
3271 
3272 	if (if_getcapenable(ifp) & IFCAP_VLAN_HWFILTER)
3273 		vtnet_rx_filter_vlan(sc);
3274 }
3275 
3276 static int
3277 vtnet_init_rx_queues(struct vtnet_softc *sc)
3278 {
3279 	device_t dev;
3280 	if_t ifp;
3281 	struct vtnet_rxq *rxq;
3282 	int i, clustersz, error;
3283 
3284 	dev = sc->vtnet_dev;
3285 	ifp = sc->vtnet_ifp;
3286 
3287 	clustersz = vtnet_rx_cluster_size(sc, if_getmtu(ifp));
3288 	sc->vtnet_rx_clustersz = clustersz;
3289 
3290 	if (sc->vtnet_flags & VTNET_FLAG_LRO_NOMRG) {
3291 		sc->vtnet_rx_nmbufs = howmany(sizeof(struct vtnet_rx_header) +
3292 		    VTNET_MAX_RX_SIZE, clustersz);
3293 		KASSERT(sc->vtnet_rx_nmbufs < sc->vtnet_rx_nsegs,
3294 		    ("%s: too many rx mbufs %d for %d segments", __func__,
3295 		    sc->vtnet_rx_nmbufs, sc->vtnet_rx_nsegs));
3296 	} else
3297 		sc->vtnet_rx_nmbufs = 1;
3298 
3299 	for (i = 0; i < sc->vtnet_act_vq_pairs; i++) {
3300 		rxq = &sc->vtnet_rxqs[i];
3301 
3302 		/* Hold the lock to satisfy asserts. */
3303 		VTNET_RXQ_LOCK(rxq);
3304 		error = vtnet_rxq_populate(rxq);
3305 		VTNET_RXQ_UNLOCK(rxq);
3306 
3307 		if (error) {
3308 			device_printf(dev, "cannot populate Rx queue %d\n", i);
3309 			return (error);
3310 		}
3311 	}
3312 
3313 	return (0);
3314 }
3315 
3316 static int
3317 vtnet_init_tx_queues(struct vtnet_softc *sc)
3318 {
3319 	struct vtnet_txq *txq;
3320 	int i;
3321 
3322 	for (i = 0; i < sc->vtnet_act_vq_pairs; i++) {
3323 		txq = &sc->vtnet_txqs[i];
3324 		txq->vtntx_watchdog = 0;
3325 		txq->vtntx_intr_threshold = vtnet_txq_intr_threshold(txq);
3326 #ifdef DEV_NETMAP
3327 		netmap_reset(NA(sc->vtnet_ifp), NR_TX, i, 0);
3328 #endif /* DEV_NETMAP */
3329 	}
3330 
3331 	return (0);
3332 }
3333 
3334 static int
3335 vtnet_init_rxtx_queues(struct vtnet_softc *sc)
3336 {
3337 	int error;
3338 
3339 	error = vtnet_init_rx_queues(sc);
3340 	if (error)
3341 		return (error);
3342 
3343 	error = vtnet_init_tx_queues(sc);
3344 	if (error)
3345 		return (error);
3346 
3347 	return (0);
3348 }
3349 
3350 static void
3351 vtnet_set_active_vq_pairs(struct vtnet_softc *sc)
3352 {
3353 	device_t dev;
3354 	int npairs;
3355 
3356 	dev = sc->vtnet_dev;
3357 
3358 	if ((sc->vtnet_flags & VTNET_FLAG_MQ) == 0) {
3359 		sc->vtnet_act_vq_pairs = 1;
3360 		return;
3361 	}
3362 
3363 	npairs = sc->vtnet_req_vq_pairs;
3364 
3365 	if (vtnet_ctrl_mq_cmd(sc, npairs) != 0) {
3366 		device_printf(dev, "cannot set active queue pairs to %d, "
3367 		    "falling back to 1 queue pair\n", npairs);
3368 		npairs = 1;
3369 	}
3370 
3371 	sc->vtnet_act_vq_pairs = npairs;
3372 }
3373 
3374 static void
3375 vtnet_update_rx_offloads(struct vtnet_softc *sc)
3376 {
3377 	if_t ifp;
3378 	uint64_t features;
3379 	int error;
3380 
3381 	ifp = sc->vtnet_ifp;
3382 	features = sc->vtnet_features;
3383 
3384 	VTNET_CORE_LOCK_ASSERT(sc);
3385 
3386 	if (if_getcapabilities(ifp) & (IFCAP_RXCSUM | IFCAP_RXCSUM_IPV6)) {
3387 		if (if_getcapenable(ifp) & (IFCAP_RXCSUM | IFCAP_RXCSUM_IPV6))
3388 			features |= VIRTIO_NET_F_GUEST_CSUM;
3389 		else
3390 			features &= ~VIRTIO_NET_F_GUEST_CSUM;
3391 	}
3392 
3393 	if (if_getcapabilities(ifp) & IFCAP_LRO && !vtnet_software_lro(sc)) {
3394 		if (if_getcapenable(ifp) & IFCAP_LRO)
3395 			features |= VTNET_LRO_FEATURES;
3396 		else
3397 			features &= ~VTNET_LRO_FEATURES;
3398 	}
3399 
3400 	error = vtnet_ctrl_guest_offloads(sc,
3401 	    features & (VIRTIO_NET_F_GUEST_CSUM | VIRTIO_NET_F_GUEST_TSO4 |
3402 		        VIRTIO_NET_F_GUEST_TSO6 | VIRTIO_NET_F_GUEST_ECN  |
3403 			VIRTIO_NET_F_GUEST_UFO));
3404 	if (error) {
3405 		device_printf(sc->vtnet_dev,
3406 		    "%s: cannot update Rx features\n", __func__);
3407 		if (if_getdrvflags(ifp) & IFF_DRV_RUNNING) {
3408 			if_setdrvflagbits(ifp, 0, IFF_DRV_RUNNING);
3409 			vtnet_init_locked(sc, 0);
3410 		}
3411 	} else
3412 		sc->vtnet_features = features;
3413 }
3414 
3415 static int
3416 vtnet_reinit(struct vtnet_softc *sc)
3417 {
3418 	if_t ifp;
3419 	int error;
3420 
3421 	ifp = sc->vtnet_ifp;
3422 
3423 	bcopy(if_getlladdr(ifp), sc->vtnet_hwaddr, ETHER_ADDR_LEN);
3424 
3425 	error = vtnet_virtio_reinit(sc);
3426 	if (error)
3427 		return (error);
3428 
3429 	vtnet_set_macaddr(sc);
3430 	vtnet_set_active_vq_pairs(sc);
3431 
3432 	if (sc->vtnet_flags & VTNET_FLAG_CTRL_VQ)
3433 		vtnet_init_rx_filters(sc);
3434 
3435 	if_sethwassist(ifp, 0);
3436 	if (if_getcapenable(ifp) & IFCAP_TXCSUM)
3437 		if_sethwassistbits(ifp, VTNET_CSUM_OFFLOAD, 0);
3438 	if (if_getcapenable(ifp) & IFCAP_TXCSUM_IPV6)
3439 		if_sethwassistbits(ifp, VTNET_CSUM_OFFLOAD_IPV6, 0);
3440 	if (if_getcapenable(ifp) & IFCAP_TSO4)
3441 		if_sethwassistbits(ifp, CSUM_IP_TSO, 0);
3442 	if (if_getcapenable(ifp) & IFCAP_TSO6)
3443 		if_sethwassistbits(ifp, CSUM_IP6_TSO, 0);
3444 
3445 	error = vtnet_init_rxtx_queues(sc);
3446 	if (error)
3447 		return (error);
3448 
3449 	return (0);
3450 }
3451 
3452 static void
3453 vtnet_init_locked(struct vtnet_softc *sc, int init_mode)
3454 {
3455 	if_t ifp;
3456 
3457 	ifp = sc->vtnet_ifp;
3458 
3459 	VTNET_CORE_LOCK_ASSERT(sc);
3460 
3461 	if (if_getdrvflags(ifp) & IFF_DRV_RUNNING)
3462 		return;
3463 
3464 	vtnet_stop(sc);
3465 
3466 #ifdef DEV_NETMAP
3467 	/* Once stopped we can update the netmap flags, if necessary. */
3468 	switch (init_mode) {
3469 	case VTNET_INIT_NETMAP_ENTER:
3470 		nm_set_native_flags(NA(ifp));
3471 		break;
3472 	case VTNET_INIT_NETMAP_EXIT:
3473 		nm_clear_native_flags(NA(ifp));
3474 		break;
3475 	}
3476 #endif /* DEV_NETMAP */
3477 
3478 	if (vtnet_reinit(sc) != 0) {
3479 		vtnet_stop(sc);
3480 		return;
3481 	}
3482 
3483 	if_setdrvflagbits(ifp, IFF_DRV_RUNNING, 0);
3484 	vtnet_update_link_status(sc);
3485 	vtnet_enable_interrupts(sc);
3486 	callout_reset(&sc->vtnet_tick_ch, hz, vtnet_tick, sc);
3487 
3488 #ifdef DEV_NETMAP
3489 	/* Re-enable txsync/rxsync. */
3490 	netmap_enable_all_rings(ifp);
3491 #endif /* DEV_NETMAP */
3492 }
3493 
3494 static void
3495 vtnet_init(void *xsc)
3496 {
3497 	struct vtnet_softc *sc;
3498 
3499 	sc = xsc;
3500 
3501 	VTNET_CORE_LOCK(sc);
3502 	vtnet_init_locked(sc, 0);
3503 	VTNET_CORE_UNLOCK(sc);
3504 }
3505 
3506 static void
3507 vtnet_free_ctrl_vq(struct vtnet_softc *sc)
3508 {
3509 
3510 	/*
3511 	 * The control virtqueue is only polled and therefore it should
3512 	 * already be empty.
3513 	 */
3514 	KASSERT(virtqueue_empty(sc->vtnet_ctrl_vq),
3515 	    ("%s: ctrl vq %p not empty", __func__, sc->vtnet_ctrl_vq));
3516 }
3517 
3518 static void
3519 vtnet_exec_ctrl_cmd(struct vtnet_softc *sc, void *cookie,
3520     struct sglist *sg, int readable, int writable)
3521 {
3522 	struct virtqueue *vq;
3523 
3524 	vq = sc->vtnet_ctrl_vq;
3525 
3526 	MPASS(sc->vtnet_flags & VTNET_FLAG_CTRL_VQ);
3527 	VTNET_CORE_LOCK_ASSERT(sc);
3528 
3529 	if (!virtqueue_empty(vq))
3530 		return;
3531 
3532 	/*
3533 	 * Poll for the response, but the command is likely completed before
3534 	 * returning from the notify.
3535 	 */
3536 	if (virtqueue_enqueue(vq, cookie, sg, readable, writable) == 0)  {
3537 		virtqueue_notify(vq);
3538 		virtqueue_poll(vq, NULL);
3539 	}
3540 }
3541 
3542 static int
3543 vtnet_ctrl_mac_cmd(struct vtnet_softc *sc, uint8_t *hwaddr)
3544 {
3545 	struct sglist_seg segs[3];
3546 	struct sglist sg;
3547 	struct {
3548 		struct virtio_net_ctrl_hdr hdr __aligned(2);
3549 		uint8_t pad1;
3550 		uint8_t addr[ETHER_ADDR_LEN] __aligned(8);
3551 		uint8_t pad2;
3552 		uint8_t ack;
3553 	} s;
3554 	int error;
3555 
3556 	error = 0;
3557 	MPASS(sc->vtnet_flags & VTNET_FLAG_CTRL_MAC);
3558 
3559 	s.hdr.class = VIRTIO_NET_CTRL_MAC;
3560 	s.hdr.cmd = VIRTIO_NET_CTRL_MAC_ADDR_SET;
3561 	bcopy(hwaddr, &s.addr[0], ETHER_ADDR_LEN);
3562 	s.ack = VIRTIO_NET_ERR;
3563 
3564 	sglist_init(&sg, nitems(segs), segs);
3565 	error |= sglist_append(&sg, &s.hdr, sizeof(struct virtio_net_ctrl_hdr));
3566 	error |= sglist_append(&sg, &s.addr[0], ETHER_ADDR_LEN);
3567 	error |= sglist_append(&sg, &s.ack, sizeof(uint8_t));
3568 	MPASS(error == 0 && sg.sg_nseg == nitems(segs));
3569 
3570 	if (error == 0)
3571 		vtnet_exec_ctrl_cmd(sc, &s.ack, &sg, sg.sg_nseg - 1, 1);
3572 
3573 	return (s.ack == VIRTIO_NET_OK ? 0 : EIO);
3574 }
3575 
3576 static int
3577 vtnet_ctrl_guest_offloads(struct vtnet_softc *sc, uint64_t offloads)
3578 {
3579 	struct sglist_seg segs[3];
3580 	struct sglist sg;
3581 	struct {
3582 		struct virtio_net_ctrl_hdr hdr __aligned(2);
3583 		uint8_t pad1;
3584 		uint64_t offloads __aligned(8);
3585 		uint8_t pad2;
3586 		uint8_t ack;
3587 	} s;
3588 	int error;
3589 
3590 	error = 0;
3591 	MPASS(sc->vtnet_features & VIRTIO_NET_F_CTRL_GUEST_OFFLOADS);
3592 
3593 	s.hdr.class = VIRTIO_NET_CTRL_GUEST_OFFLOADS;
3594 	s.hdr.cmd = VIRTIO_NET_CTRL_GUEST_OFFLOADS_SET;
3595 	s.offloads = vtnet_gtoh64(sc, offloads);
3596 	s.ack = VIRTIO_NET_ERR;
3597 
3598 	sglist_init(&sg, nitems(segs), segs);
3599 	error |= sglist_append(&sg, &s.hdr, sizeof(struct virtio_net_ctrl_hdr));
3600 	error |= sglist_append(&sg, &s.offloads, sizeof(uint64_t));
3601 	error |= sglist_append(&sg, &s.ack, sizeof(uint8_t));
3602 	MPASS(error == 0 && sg.sg_nseg == nitems(segs));
3603 
3604 	if (error == 0)
3605 		vtnet_exec_ctrl_cmd(sc, &s.ack, &sg, sg.sg_nseg - 1, 1);
3606 
3607 	return (s.ack == VIRTIO_NET_OK ? 0 : EIO);
3608 }
3609 
3610 static int
3611 vtnet_ctrl_mq_cmd(struct vtnet_softc *sc, uint16_t npairs)
3612 {
3613 	struct sglist_seg segs[3];
3614 	struct sglist sg;
3615 	struct {
3616 		struct virtio_net_ctrl_hdr hdr __aligned(2);
3617 		uint8_t pad1;
3618 		struct virtio_net_ctrl_mq mq __aligned(2);
3619 		uint8_t pad2;
3620 		uint8_t ack;
3621 	} s;
3622 	int error;
3623 
3624 	error = 0;
3625 	MPASS(sc->vtnet_flags & VTNET_FLAG_MQ);
3626 
3627 	s.hdr.class = VIRTIO_NET_CTRL_MQ;
3628 	s.hdr.cmd = VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET;
3629 	s.mq.virtqueue_pairs = vtnet_gtoh16(sc, npairs);
3630 	s.ack = VIRTIO_NET_ERR;
3631 
3632 	sglist_init(&sg, nitems(segs), segs);
3633 	error |= sglist_append(&sg, &s.hdr, sizeof(struct virtio_net_ctrl_hdr));
3634 	error |= sglist_append(&sg, &s.mq, sizeof(struct virtio_net_ctrl_mq));
3635 	error |= sglist_append(&sg, &s.ack, sizeof(uint8_t));
3636 	MPASS(error == 0 && sg.sg_nseg == nitems(segs));
3637 
3638 	if (error == 0)
3639 		vtnet_exec_ctrl_cmd(sc, &s.ack, &sg, sg.sg_nseg - 1, 1);
3640 
3641 	return (s.ack == VIRTIO_NET_OK ? 0 : EIO);
3642 }
3643 
3644 static int
3645 vtnet_ctrl_rx_cmd(struct vtnet_softc *sc, uint8_t cmd, bool on)
3646 {
3647 	struct sglist_seg segs[3];
3648 	struct sglist sg;
3649 	struct {
3650 		struct virtio_net_ctrl_hdr hdr __aligned(2);
3651 		uint8_t pad1;
3652 		uint8_t onoff;
3653 		uint8_t pad2;
3654 		uint8_t ack;
3655 	} s;
3656 	int error;
3657 
3658 	error = 0;
3659 	MPASS(sc->vtnet_flags & VTNET_FLAG_CTRL_RX);
3660 
3661 	s.hdr.class = VIRTIO_NET_CTRL_RX;
3662 	s.hdr.cmd = cmd;
3663 	s.onoff = on;
3664 	s.ack = VIRTIO_NET_ERR;
3665 
3666 	sglist_init(&sg, nitems(segs), segs);
3667 	error |= sglist_append(&sg, &s.hdr, sizeof(struct virtio_net_ctrl_hdr));
3668 	error |= sglist_append(&sg, &s.onoff, sizeof(uint8_t));
3669 	error |= sglist_append(&sg, &s.ack, sizeof(uint8_t));
3670 	MPASS(error == 0 && sg.sg_nseg == nitems(segs));
3671 
3672 	if (error == 0)
3673 		vtnet_exec_ctrl_cmd(sc, &s.ack, &sg, sg.sg_nseg - 1, 1);
3674 
3675 	return (s.ack == VIRTIO_NET_OK ? 0 : EIO);
3676 }
3677 
3678 static int
3679 vtnet_set_promisc(struct vtnet_softc *sc, bool on)
3680 {
3681 	return (vtnet_ctrl_rx_cmd(sc, VIRTIO_NET_CTRL_RX_PROMISC, on));
3682 }
3683 
3684 static int
3685 vtnet_set_allmulti(struct vtnet_softc *sc, bool on)
3686 {
3687 	return (vtnet_ctrl_rx_cmd(sc, VIRTIO_NET_CTRL_RX_ALLMULTI, on));
3688 }
3689 
3690 static void
3691 vtnet_rx_filter(struct vtnet_softc *sc)
3692 {
3693 	device_t dev;
3694 	if_t ifp;
3695 
3696 	dev = sc->vtnet_dev;
3697 	ifp = sc->vtnet_ifp;
3698 
3699 	VTNET_CORE_LOCK_ASSERT(sc);
3700 
3701 	if (vtnet_set_promisc(sc, if_getflags(ifp) & IFF_PROMISC) != 0) {
3702 		device_printf(dev, "cannot %s promiscuous mode\n",
3703 		    if_getflags(ifp) & IFF_PROMISC ? "enable" : "disable");
3704 	}
3705 
3706 	if (vtnet_set_allmulti(sc, if_getflags(ifp) & IFF_ALLMULTI) != 0) {
3707 		device_printf(dev, "cannot %s all-multicast mode\n",
3708 		    if_getflags(ifp) & IFF_ALLMULTI ? "enable" : "disable");
3709 	}
3710 }
3711 
3712 static u_int
3713 vtnet_copy_ifaddr(void *arg, struct sockaddr_dl *sdl, u_int ucnt)
3714 {
3715 	struct vtnet_softc *sc = arg;
3716 
3717 	if (memcmp(LLADDR(sdl), sc->vtnet_hwaddr, ETHER_ADDR_LEN) == 0)
3718 		return (0);
3719 
3720 	if (ucnt < VTNET_MAX_MAC_ENTRIES)
3721 		bcopy(LLADDR(sdl),
3722 		    &sc->vtnet_mac_filter->vmf_unicast.macs[ucnt],
3723 		    ETHER_ADDR_LEN);
3724 
3725 	return (1);
3726 }
3727 
3728 static u_int
3729 vtnet_copy_maddr(void *arg, struct sockaddr_dl *sdl, u_int mcnt)
3730 {
3731 	struct vtnet_mac_filter *filter = arg;
3732 
3733 	if (mcnt < VTNET_MAX_MAC_ENTRIES)
3734 		bcopy(LLADDR(sdl), &filter->vmf_multicast.macs[mcnt],
3735 		    ETHER_ADDR_LEN);
3736 
3737 	return (1);
3738 }
3739 
3740 static void
3741 vtnet_rx_filter_mac(struct vtnet_softc *sc)
3742 {
3743 	struct virtio_net_ctrl_hdr hdr __aligned(2);
3744 	struct vtnet_mac_filter *filter;
3745 	struct sglist_seg segs[4];
3746 	struct sglist sg;
3747 	if_t ifp;
3748 	bool promisc, allmulti;
3749 	u_int ucnt, mcnt;
3750 	int error;
3751 	uint8_t ack;
3752 
3753 	ifp = sc->vtnet_ifp;
3754 	filter = sc->vtnet_mac_filter;
3755 	error = 0;
3756 
3757 	MPASS(sc->vtnet_flags & VTNET_FLAG_CTRL_RX);
3758 	VTNET_CORE_LOCK_ASSERT(sc);
3759 
3760 	/* Unicast MAC addresses: */
3761 	ucnt = if_foreach_lladdr(ifp, vtnet_copy_ifaddr, sc);
3762 	promisc = (ucnt > VTNET_MAX_MAC_ENTRIES);
3763 
3764 	if (promisc) {
3765 		ucnt = 0;
3766 		if_printf(ifp, "more than %d MAC addresses assigned, "
3767 		    "falling back to promiscuous mode\n",
3768 		    VTNET_MAX_MAC_ENTRIES);
3769 	}
3770 
3771 	/* Multicast MAC addresses: */
3772 	mcnt = if_foreach_llmaddr(ifp, vtnet_copy_maddr, filter);
3773 	allmulti = (mcnt > VTNET_MAX_MAC_ENTRIES);
3774 
3775 	if (allmulti) {
3776 		mcnt = 0;
3777 		if_printf(ifp, "more than %d multicast MAC addresses "
3778 		    "assigned, falling back to all-multicast mode\n",
3779 		    VTNET_MAX_MAC_ENTRIES);
3780 	}
3781 
3782 	if (promisc && allmulti)
3783 		goto out;
3784 
3785 	filter->vmf_unicast.nentries = vtnet_gtoh32(sc, ucnt);
3786 	filter->vmf_multicast.nentries = vtnet_gtoh32(sc, mcnt);
3787 
3788 	hdr.class = VIRTIO_NET_CTRL_MAC;
3789 	hdr.cmd = VIRTIO_NET_CTRL_MAC_TABLE_SET;
3790 	ack = VIRTIO_NET_ERR;
3791 
3792 	sglist_init(&sg, nitems(segs), segs);
3793 	error |= sglist_append(&sg, &hdr, sizeof(struct virtio_net_ctrl_hdr));
3794 	error |= sglist_append(&sg, &filter->vmf_unicast,
3795 	    sizeof(uint32_t) + ucnt * ETHER_ADDR_LEN);
3796 	error |= sglist_append(&sg, &filter->vmf_multicast,
3797 	    sizeof(uint32_t) + mcnt * ETHER_ADDR_LEN);
3798 	error |= sglist_append(&sg, &ack, sizeof(uint8_t));
3799 	MPASS(error == 0 && sg.sg_nseg == nitems(segs));
3800 
3801 	if (error == 0)
3802 		vtnet_exec_ctrl_cmd(sc, &ack, &sg, sg.sg_nseg - 1, 1);
3803 	if (ack != VIRTIO_NET_OK)
3804 		if_printf(ifp, "error setting host MAC filter table\n");
3805 
3806 out:
3807 	if (promisc != 0 && vtnet_set_promisc(sc, true) != 0)
3808 		if_printf(ifp, "cannot enable promiscuous mode\n");
3809 	if (allmulti != 0 && vtnet_set_allmulti(sc, true) != 0)
3810 		if_printf(ifp, "cannot enable all-multicast mode\n");
3811 }
3812 
3813 static int
3814 vtnet_exec_vlan_filter(struct vtnet_softc *sc, int add, uint16_t tag)
3815 {
3816 	struct sglist_seg segs[3];
3817 	struct sglist sg;
3818 	struct {
3819 		struct virtio_net_ctrl_hdr hdr __aligned(2);
3820 		uint8_t pad1;
3821 		uint16_t tag __aligned(2);
3822 		uint8_t pad2;
3823 		uint8_t ack;
3824 	} s;
3825 	int error;
3826 
3827 	error = 0;
3828 	MPASS(sc->vtnet_flags & VTNET_FLAG_VLAN_FILTER);
3829 
3830 	s.hdr.class = VIRTIO_NET_CTRL_VLAN;
3831 	s.hdr.cmd = add ? VIRTIO_NET_CTRL_VLAN_ADD : VIRTIO_NET_CTRL_VLAN_DEL;
3832 	s.tag = vtnet_gtoh16(sc, tag);
3833 	s.ack = VIRTIO_NET_ERR;
3834 
3835 	sglist_init(&sg, nitems(segs), segs);
3836 	error |= sglist_append(&sg, &s.hdr, sizeof(struct virtio_net_ctrl_hdr));
3837 	error |= sglist_append(&sg, &s.tag, sizeof(uint16_t));
3838 	error |= sglist_append(&sg, &s.ack, sizeof(uint8_t));
3839 	MPASS(error == 0 && sg.sg_nseg == nitems(segs));
3840 
3841 	if (error == 0)
3842 		vtnet_exec_ctrl_cmd(sc, &s.ack, &sg, sg.sg_nseg - 1, 1);
3843 
3844 	return (s.ack == VIRTIO_NET_OK ? 0 : EIO);
3845 }
3846 
3847 static void
3848 vtnet_rx_filter_vlan(struct vtnet_softc *sc)
3849 {
3850 	int i, bit;
3851 	uint32_t w;
3852 	uint16_t tag;
3853 
3854 	MPASS(sc->vtnet_flags & VTNET_FLAG_VLAN_FILTER);
3855 	VTNET_CORE_LOCK_ASSERT(sc);
3856 
3857 	/* Enable the filter for each configured VLAN. */
3858 	for (i = 0; i < VTNET_VLAN_FILTER_NWORDS; i++) {
3859 		w = sc->vtnet_vlan_filter[i];
3860 
3861 		while ((bit = ffs(w) - 1) != -1) {
3862 			w &= ~(1 << bit);
3863 			tag = sizeof(w) * CHAR_BIT * i + bit;
3864 
3865 			if (vtnet_exec_vlan_filter(sc, 1, tag) != 0) {
3866 				device_printf(sc->vtnet_dev,
3867 				    "cannot enable VLAN %d filter\n", tag);
3868 			}
3869 		}
3870 	}
3871 }
3872 
3873 static void
3874 vtnet_update_vlan_filter(struct vtnet_softc *sc, int add, uint16_t tag)
3875 {
3876 	if_t ifp;
3877 	int idx, bit;
3878 
3879 	ifp = sc->vtnet_ifp;
3880 	idx = (tag >> 5) & 0x7F;
3881 	bit = tag & 0x1F;
3882 
3883 	if (tag == 0 || tag > 4095)
3884 		return;
3885 
3886 	VTNET_CORE_LOCK(sc);
3887 
3888 	if (add)
3889 		sc->vtnet_vlan_filter[idx] |= (1 << bit);
3890 	else
3891 		sc->vtnet_vlan_filter[idx] &= ~(1 << bit);
3892 
3893 	if (if_getcapenable(ifp) & IFCAP_VLAN_HWFILTER &&
3894 	    if_getdrvflags(ifp) & IFF_DRV_RUNNING &&
3895 	    vtnet_exec_vlan_filter(sc, add, tag) != 0) {
3896 		device_printf(sc->vtnet_dev,
3897 		    "cannot %s VLAN %d %s the host filter table\n",
3898 		    add ? "add" : "remove", tag, add ? "to" : "from");
3899 	}
3900 
3901 	VTNET_CORE_UNLOCK(sc);
3902 }
3903 
3904 static void
3905 vtnet_register_vlan(void *arg, if_t ifp, uint16_t tag)
3906 {
3907 
3908 	if (if_getsoftc(ifp) != arg)
3909 		return;
3910 
3911 	vtnet_update_vlan_filter(arg, 1, tag);
3912 }
3913 
3914 static void
3915 vtnet_unregister_vlan(void *arg, if_t ifp, uint16_t tag)
3916 {
3917 
3918 	if (if_getsoftc(ifp) != arg)
3919 		return;
3920 
3921 	vtnet_update_vlan_filter(arg, 0, tag);
3922 }
3923 
3924 static void
3925 vtnet_update_speed_duplex(struct vtnet_softc *sc)
3926 {
3927 	if_t ifp;
3928 	uint32_t speed;
3929 
3930 	ifp = sc->vtnet_ifp;
3931 
3932 	if ((sc->vtnet_features & VIRTIO_NET_F_SPEED_DUPLEX) == 0)
3933 		return;
3934 
3935 	/* BMV: Ignore duplex. */
3936 	speed = virtio_read_dev_config_4(sc->vtnet_dev,
3937 	    offsetof(struct virtio_net_config, speed));
3938 	if (speed != UINT32_MAX)
3939 		if_setbaudrate(ifp, IF_Mbps(speed));
3940 }
3941 
3942 static int
3943 vtnet_is_link_up(struct vtnet_softc *sc)
3944 {
3945 	uint16_t status;
3946 
3947 	if ((sc->vtnet_features & VIRTIO_NET_F_STATUS) == 0)
3948 		return (1);
3949 
3950 	status = virtio_read_dev_config_2(sc->vtnet_dev,
3951 	    offsetof(struct virtio_net_config, status));
3952 
3953 	return ((status & VIRTIO_NET_S_LINK_UP) != 0);
3954 }
3955 
3956 static void
3957 vtnet_update_link_status(struct vtnet_softc *sc)
3958 {
3959 	if_t ifp;
3960 	int link;
3961 
3962 	ifp = sc->vtnet_ifp;
3963 	VTNET_CORE_LOCK_ASSERT(sc);
3964 	link = vtnet_is_link_up(sc);
3965 
3966 	/* Notify if the link status has changed. */
3967 	if (link != 0 && sc->vtnet_link_active == 0) {
3968 		vtnet_update_speed_duplex(sc);
3969 		sc->vtnet_link_active = 1;
3970 		if_link_state_change(ifp, LINK_STATE_UP);
3971 	} else if (link == 0 && sc->vtnet_link_active != 0) {
3972 		sc->vtnet_link_active = 0;
3973 		if_link_state_change(ifp, LINK_STATE_DOWN);
3974 	}
3975 }
3976 
3977 static int
3978 vtnet_ifmedia_upd(if_t ifp __unused)
3979 {
3980 	return (EOPNOTSUPP);
3981 }
3982 
3983 static void
3984 vtnet_ifmedia_sts(if_t ifp, struct ifmediareq *ifmr)
3985 {
3986 	struct vtnet_softc *sc;
3987 
3988 	sc = if_getsoftc(ifp);
3989 
3990 	ifmr->ifm_status = IFM_AVALID;
3991 	ifmr->ifm_active = IFM_ETHER;
3992 
3993 	VTNET_CORE_LOCK(sc);
3994 	if (vtnet_is_link_up(sc) != 0) {
3995 		ifmr->ifm_status |= IFM_ACTIVE;
3996 		ifmr->ifm_active |= IFM_10G_T | IFM_FDX;
3997 	} else
3998 		ifmr->ifm_active |= IFM_NONE;
3999 	VTNET_CORE_UNLOCK(sc);
4000 }
4001 
4002 static void
4003 vtnet_get_macaddr(struct vtnet_softc *sc)
4004 {
4005 
4006 	if (sc->vtnet_flags & VTNET_FLAG_MAC) {
4007 		virtio_read_device_config_array(sc->vtnet_dev,
4008 		    offsetof(struct virtio_net_config, mac),
4009 		    &sc->vtnet_hwaddr[0], sizeof(uint8_t), ETHER_ADDR_LEN);
4010 	} else {
4011 		/* Generate a random locally administered unicast address. */
4012 		sc->vtnet_hwaddr[0] = 0xB2;
4013 		arc4rand(&sc->vtnet_hwaddr[1], ETHER_ADDR_LEN - 1, 0);
4014 	}
4015 }
4016 
4017 static void
4018 vtnet_set_macaddr(struct vtnet_softc *sc)
4019 {
4020 	device_t dev;
4021 	int error;
4022 
4023 	dev = sc->vtnet_dev;
4024 
4025 	if (sc->vtnet_flags & VTNET_FLAG_CTRL_MAC) {
4026 		error = vtnet_ctrl_mac_cmd(sc, sc->vtnet_hwaddr);
4027 		if (error)
4028 			device_printf(dev, "unable to set MAC address\n");
4029 		return;
4030 	}
4031 
4032 	/* MAC in config is read-only in modern VirtIO. */
4033 	if (!vtnet_modern(sc) && sc->vtnet_flags & VTNET_FLAG_MAC) {
4034 		for (int i = 0; i < ETHER_ADDR_LEN; i++) {
4035 			virtio_write_dev_config_1(dev,
4036 			    offsetof(struct virtio_net_config, mac) + i,
4037 			    sc->vtnet_hwaddr[i]);
4038 		}
4039 	}
4040 }
4041 
4042 static void
4043 vtnet_attached_set_macaddr(struct vtnet_softc *sc)
4044 {
4045 
4046 	/* Assign MAC address if it was generated. */
4047 	if ((sc->vtnet_flags & VTNET_FLAG_MAC) == 0)
4048 		vtnet_set_macaddr(sc);
4049 }
4050 
4051 static void
4052 vtnet_vlan_tag_remove(struct mbuf *m)
4053 {
4054 	struct ether_vlan_header *evh;
4055 
4056 	evh = mtod(m, struct ether_vlan_header *);
4057 	m->m_pkthdr.ether_vtag = ntohs(evh->evl_tag);
4058 	m->m_flags |= M_VLANTAG;
4059 
4060 	/* Strip the 802.1Q header. */
4061 	bcopy((char *) evh, (char *) evh + ETHER_VLAN_ENCAP_LEN,
4062 	    ETHER_HDR_LEN - ETHER_TYPE_LEN);
4063 	m_adj(m, ETHER_VLAN_ENCAP_LEN);
4064 }
4065 
4066 static void
4067 vtnet_set_rx_process_limit(struct vtnet_softc *sc)
4068 {
4069 	int limit;
4070 
4071 	limit = vtnet_tunable_int(sc, "rx_process_limit",
4072 	    vtnet_rx_process_limit);
4073 	if (limit < 0)
4074 		limit = INT_MAX;
4075 	sc->vtnet_rx_process_limit = limit;
4076 }
4077 
4078 static void
4079 vtnet_setup_rxq_sysctl(struct sysctl_ctx_list *ctx,
4080     struct sysctl_oid_list *child, struct vtnet_rxq *rxq)
4081 {
4082 	struct sysctl_oid *node;
4083 	struct sysctl_oid_list *list;
4084 	struct vtnet_rxq_stats *stats;
4085 	char namebuf[16];
4086 
4087 	snprintf(namebuf, sizeof(namebuf), "rxq%d", rxq->vtnrx_id);
4088 	node = SYSCTL_ADD_NODE(ctx, child, OID_AUTO, namebuf,
4089 	    CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "Receive Queue");
4090 	list = SYSCTL_CHILDREN(node);
4091 
4092 	stats = &rxq->vtnrx_stats;
4093 
4094 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "ipackets", CTLFLAG_RD,
4095 	    &stats->vrxs_ipackets, "Receive packets");
4096 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "ibytes", CTLFLAG_RD,
4097 	    &stats->vrxs_ibytes, "Receive bytes");
4098 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "iqdrops", CTLFLAG_RD,
4099 	    &stats->vrxs_iqdrops, "Receive drops");
4100 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "ierrors", CTLFLAG_RD,
4101 	    &stats->vrxs_ierrors, "Receive errors");
4102 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "csum", CTLFLAG_RD,
4103 	    &stats->vrxs_csum, "Receive checksum offloaded");
4104 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "csum_failed", CTLFLAG_RD,
4105 	    &stats->vrxs_csum_failed, "Receive checksum offload failed");
4106 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "host_lro", CTLFLAG_RD,
4107 	    &stats->vrxs_host_lro, "Receive host segmentation offloaded");
4108 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "rescheduled", CTLFLAG_RD,
4109 	    &stats->vrxs_rescheduled,
4110 	    "Receive interrupt handler rescheduled");
4111 }
4112 
4113 static void
4114 vtnet_setup_txq_sysctl(struct sysctl_ctx_list *ctx,
4115     struct sysctl_oid_list *child, struct vtnet_txq *txq)
4116 {
4117 	struct sysctl_oid *node;
4118 	struct sysctl_oid_list *list;
4119 	struct vtnet_txq_stats *stats;
4120 	char namebuf[16];
4121 
4122 	snprintf(namebuf, sizeof(namebuf), "txq%d", txq->vtntx_id);
4123 	node = SYSCTL_ADD_NODE(ctx, child, OID_AUTO, namebuf,
4124 	    CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "Transmit Queue");
4125 	list = SYSCTL_CHILDREN(node);
4126 
4127 	stats = &txq->vtntx_stats;
4128 
4129 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "opackets", CTLFLAG_RD,
4130 	    &stats->vtxs_opackets, "Transmit packets");
4131 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "obytes", CTLFLAG_RD,
4132 	    &stats->vtxs_obytes, "Transmit bytes");
4133 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "omcasts", CTLFLAG_RD,
4134 	    &stats->vtxs_omcasts, "Transmit multicasts");
4135 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "csum", CTLFLAG_RD,
4136 	    &stats->vtxs_csum, "Transmit checksum offloaded");
4137 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "tso", CTLFLAG_RD,
4138 	    &stats->vtxs_tso, "Transmit TCP segmentation offloaded");
4139 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "rescheduled", CTLFLAG_RD,
4140 	    &stats->vtxs_rescheduled,
4141 	    "Transmit interrupt handler rescheduled");
4142 }
4143 
4144 static void
4145 vtnet_setup_queue_sysctl(struct vtnet_softc *sc)
4146 {
4147 	device_t dev;
4148 	struct sysctl_ctx_list *ctx;
4149 	struct sysctl_oid *tree;
4150 	struct sysctl_oid_list *child;
4151 	int i;
4152 
4153 	dev = sc->vtnet_dev;
4154 	ctx = device_get_sysctl_ctx(dev);
4155 	tree = device_get_sysctl_tree(dev);
4156 	child = SYSCTL_CHILDREN(tree);
4157 
4158 	for (i = 0; i < sc->vtnet_req_vq_pairs; i++) {
4159 		vtnet_setup_rxq_sysctl(ctx, child, &sc->vtnet_rxqs[i]);
4160 		vtnet_setup_txq_sysctl(ctx, child, &sc->vtnet_txqs[i]);
4161 	}
4162 }
4163 
4164 static void
4165 vtnet_setup_stat_sysctl(struct sysctl_ctx_list *ctx,
4166     struct sysctl_oid_list *child, struct vtnet_softc *sc)
4167 {
4168 	struct vtnet_statistics *stats;
4169 	struct vtnet_rxq_stats rxaccum;
4170 	struct vtnet_txq_stats txaccum;
4171 
4172 	vtnet_accum_stats(sc, &rxaccum, &txaccum);
4173 
4174 	stats = &sc->vtnet_stats;
4175 	stats->rx_csum_offloaded = rxaccum.vrxs_csum;
4176 	stats->rx_csum_failed = rxaccum.vrxs_csum_failed;
4177 	stats->rx_task_rescheduled = rxaccum.vrxs_rescheduled;
4178 	stats->tx_csum_offloaded = txaccum.vtxs_csum;
4179 	stats->tx_tso_offloaded = txaccum.vtxs_tso;
4180 	stats->tx_task_rescheduled = txaccum.vtxs_rescheduled;
4181 
4182 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "mbuf_alloc_failed",
4183 	    CTLFLAG_RD, &stats->mbuf_alloc_failed,
4184 	    "Mbuf cluster allocation failures");
4185 
4186 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "rx_frame_too_large",
4187 	    CTLFLAG_RD, &stats->rx_frame_too_large,
4188 	    "Received frame larger than the mbuf chain");
4189 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "rx_enq_replacement_failed",
4190 	    CTLFLAG_RD, &stats->rx_enq_replacement_failed,
4191 	    "Enqueuing the replacement receive mbuf failed");
4192 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "rx_mergeable_failed",
4193 	    CTLFLAG_RD, &stats->rx_mergeable_failed,
4194 	    "Mergeable buffers receive failures");
4195 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "rx_csum_bad_ethtype",
4196 	    CTLFLAG_RD, &stats->rx_csum_bad_ethtype,
4197 	    "Received checksum offloaded buffer with unsupported "
4198 	    "Ethernet type");
4199 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "rx_csum_bad_ipproto",
4200 	    CTLFLAG_RD, &stats->rx_csum_bad_ipproto,
4201 	    "Received checksum offloaded buffer with incorrect IP protocol");
4202 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "rx_csum_bad_offset",
4203 	    CTLFLAG_RD, &stats->rx_csum_bad_offset,
4204 	    "Received checksum offloaded buffer with incorrect offset");
4205 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "rx_csum_bad_proto",
4206 	    CTLFLAG_RD, &stats->rx_csum_bad_proto,
4207 	    "Received checksum offloaded buffer with incorrect protocol");
4208 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "rx_csum_failed",
4209 	    CTLFLAG_RD, &stats->rx_csum_failed,
4210 	    "Received buffer checksum offload failed");
4211 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "rx_csum_offloaded",
4212 	    CTLFLAG_RD, &stats->rx_csum_offloaded,
4213 	    "Received buffer checksum offload succeeded");
4214 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "rx_task_rescheduled",
4215 	    CTLFLAG_RD, &stats->rx_task_rescheduled,
4216 	    "Times the receive interrupt task rescheduled itself");
4217 
4218 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "tx_csum_unknown_ethtype",
4219 	    CTLFLAG_RD, &stats->tx_csum_unknown_ethtype,
4220 	    "Aborted transmit of checksum offloaded buffer with unknown "
4221 	    "Ethernet type");
4222 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "tx_csum_proto_mismatch",
4223 	    CTLFLAG_RD, &stats->tx_csum_proto_mismatch,
4224 	    "Aborted transmit of checksum offloaded buffer because mismatched "
4225 	    "protocols");
4226 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "tx_tso_not_tcp",
4227 	    CTLFLAG_RD, &stats->tx_tso_not_tcp,
4228 	    "Aborted transmit of TSO buffer with non TCP protocol");
4229 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "tx_tso_without_csum",
4230 	    CTLFLAG_RD, &stats->tx_tso_without_csum,
4231 	    "Aborted transmit of TSO buffer without TCP checksum offload");
4232 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "tx_defragged",
4233 	    CTLFLAG_RD, &stats->tx_defragged,
4234 	    "Transmit mbufs defragged");
4235 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "tx_defrag_failed",
4236 	    CTLFLAG_RD, &stats->tx_defrag_failed,
4237 	    "Aborted transmit of buffer because defrag failed");
4238 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "tx_csum_offloaded",
4239 	    CTLFLAG_RD, &stats->tx_csum_offloaded,
4240 	    "Offloaded checksum of transmitted buffer");
4241 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "tx_tso_offloaded",
4242 	    CTLFLAG_RD, &stats->tx_tso_offloaded,
4243 	    "Segmentation offload of transmitted buffer");
4244 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "tx_task_rescheduled",
4245 	    CTLFLAG_RD, &stats->tx_task_rescheduled,
4246 	    "Times the transmit interrupt task rescheduled itself");
4247 }
4248 
4249 static void
4250 vtnet_setup_sysctl(struct vtnet_softc *sc)
4251 {
4252 	device_t dev;
4253 	struct sysctl_ctx_list *ctx;
4254 	struct sysctl_oid *tree;
4255 	struct sysctl_oid_list *child;
4256 
4257 	dev = sc->vtnet_dev;
4258 	ctx = device_get_sysctl_ctx(dev);
4259 	tree = device_get_sysctl_tree(dev);
4260 	child = SYSCTL_CHILDREN(tree);
4261 
4262 	SYSCTL_ADD_INT(ctx, child, OID_AUTO, "max_vq_pairs",
4263 	    CTLFLAG_RD, &sc->vtnet_max_vq_pairs, 0,
4264 	    "Number of maximum supported virtqueue pairs");
4265 	SYSCTL_ADD_INT(ctx, child, OID_AUTO, "req_vq_pairs",
4266 	    CTLFLAG_RD, &sc->vtnet_req_vq_pairs, 0,
4267 	    "Number of requested virtqueue pairs");
4268 	SYSCTL_ADD_INT(ctx, child, OID_AUTO, "act_vq_pairs",
4269 	    CTLFLAG_RD, &sc->vtnet_act_vq_pairs, 0,
4270 	    "Number of active virtqueue pairs");
4271 
4272 	vtnet_setup_stat_sysctl(ctx, child, sc);
4273 }
4274 
4275 static void
4276 vtnet_load_tunables(struct vtnet_softc *sc)
4277 {
4278 
4279 	sc->vtnet_lro_entry_count = vtnet_tunable_int(sc,
4280 	    "lro_entry_count", vtnet_lro_entry_count);
4281 	if (sc->vtnet_lro_entry_count < TCP_LRO_ENTRIES)
4282 		sc->vtnet_lro_entry_count = TCP_LRO_ENTRIES;
4283 
4284 	sc->vtnet_lro_mbufq_depth = vtnet_tunable_int(sc,
4285 	    "lro_mbufq_depth", vtnet_lro_mbufq_depth);
4286 }
4287 
4288 static int
4289 vtnet_rxq_enable_intr(struct vtnet_rxq *rxq)
4290 {
4291 
4292 	return (virtqueue_enable_intr(rxq->vtnrx_vq));
4293 }
4294 
4295 static void
4296 vtnet_rxq_disable_intr(struct vtnet_rxq *rxq)
4297 {
4298 
4299 	virtqueue_disable_intr(rxq->vtnrx_vq);
4300 }
4301 
4302 static int
4303 vtnet_txq_enable_intr(struct vtnet_txq *txq)
4304 {
4305 	struct virtqueue *vq;
4306 
4307 	vq = txq->vtntx_vq;
4308 
4309 	if (vtnet_txq_below_threshold(txq) != 0)
4310 		return (virtqueue_postpone_intr(vq, VQ_POSTPONE_LONG));
4311 
4312 	/*
4313 	 * The free count is above our threshold. Keep the Tx interrupt
4314 	 * disabled until the queue is fuller.
4315 	 */
4316 	return (0);
4317 }
4318 
4319 static void
4320 vtnet_txq_disable_intr(struct vtnet_txq *txq)
4321 {
4322 
4323 	virtqueue_disable_intr(txq->vtntx_vq);
4324 }
4325 
4326 static void
4327 vtnet_enable_rx_interrupts(struct vtnet_softc *sc)
4328 {
4329 	struct vtnet_rxq *rxq;
4330 	int i;
4331 
4332 	for (i = 0; i < sc->vtnet_act_vq_pairs; i++) {
4333 		rxq = &sc->vtnet_rxqs[i];
4334 		if (vtnet_rxq_enable_intr(rxq) != 0)
4335 			taskqueue_enqueue(rxq->vtnrx_tq, &rxq->vtnrx_intrtask);
4336 	}
4337 }
4338 
4339 static void
4340 vtnet_enable_tx_interrupts(struct vtnet_softc *sc)
4341 {
4342 	int i;
4343 
4344 	for (i = 0; i < sc->vtnet_act_vq_pairs; i++)
4345 		vtnet_txq_enable_intr(&sc->vtnet_txqs[i]);
4346 }
4347 
4348 static void
4349 vtnet_enable_interrupts(struct vtnet_softc *sc)
4350 {
4351 
4352 	vtnet_enable_rx_interrupts(sc);
4353 	vtnet_enable_tx_interrupts(sc);
4354 }
4355 
4356 static void
4357 vtnet_disable_rx_interrupts(struct vtnet_softc *sc)
4358 {
4359 	int i;
4360 
4361 	for (i = 0; i < sc->vtnet_max_vq_pairs; i++)
4362 		vtnet_rxq_disable_intr(&sc->vtnet_rxqs[i]);
4363 }
4364 
4365 static void
4366 vtnet_disable_tx_interrupts(struct vtnet_softc *sc)
4367 {
4368 	int i;
4369 
4370 	for (i = 0; i < sc->vtnet_max_vq_pairs; i++)
4371 		vtnet_txq_disable_intr(&sc->vtnet_txqs[i]);
4372 }
4373 
4374 static void
4375 vtnet_disable_interrupts(struct vtnet_softc *sc)
4376 {
4377 
4378 	vtnet_disable_rx_interrupts(sc);
4379 	vtnet_disable_tx_interrupts(sc);
4380 }
4381 
4382 static int
4383 vtnet_tunable_int(struct vtnet_softc *sc, const char *knob, int def)
4384 {
4385 	char path[64];
4386 
4387 	snprintf(path, sizeof(path),
4388 	    "hw.vtnet.%d.%s", device_get_unit(sc->vtnet_dev), knob);
4389 	TUNABLE_INT_FETCH(path, &def);
4390 
4391 	return (def);
4392 }
4393 
4394 #ifdef DEBUGNET
4395 static void
4396 vtnet_debugnet_init(if_t ifp, int *nrxr, int *ncl, int *clsize)
4397 {
4398 	struct vtnet_softc *sc;
4399 
4400 	sc = if_getsoftc(ifp);
4401 
4402 	VTNET_CORE_LOCK(sc);
4403 	*nrxr = sc->vtnet_req_vq_pairs;
4404 	*ncl = DEBUGNET_MAX_IN_FLIGHT;
4405 	*clsize = sc->vtnet_rx_clustersz;
4406 	VTNET_CORE_UNLOCK(sc);
4407 }
4408 
4409 static void
4410 vtnet_debugnet_event(if_t ifp __unused, enum debugnet_ev event)
4411 {
4412 	struct vtnet_softc *sc;
4413 	static bool sw_lro_enabled = false;
4414 
4415 	/*
4416 	 * Disable software LRO, since it would require entering the network
4417 	 * epoch when calling vtnet_txq_eof() in vtnet_debugnet_poll().
4418 	 */
4419 	sc = if_getsoftc(ifp);
4420 	switch (event) {
4421 	case DEBUGNET_START:
4422 		sw_lro_enabled = (sc->vtnet_flags & VTNET_FLAG_SW_LRO) != 0;
4423 		if (sw_lro_enabled)
4424 			sc->vtnet_flags &= ~VTNET_FLAG_SW_LRO;
4425 		break;
4426 	case DEBUGNET_END:
4427 		if (sw_lro_enabled)
4428 			sc->vtnet_flags |= VTNET_FLAG_SW_LRO;
4429 		break;
4430 	}
4431 }
4432 
4433 static int
4434 vtnet_debugnet_transmit(if_t ifp, struct mbuf *m)
4435 {
4436 	struct vtnet_softc *sc;
4437 	struct vtnet_txq *txq;
4438 	int error;
4439 
4440 	sc = if_getsoftc(ifp);
4441 	if ((if_getdrvflags(ifp) & (IFF_DRV_RUNNING | IFF_DRV_OACTIVE)) !=
4442 	    IFF_DRV_RUNNING)
4443 		return (EBUSY);
4444 
4445 	txq = &sc->vtnet_txqs[0];
4446 	error = vtnet_txq_encap(txq, &m, M_NOWAIT | M_USE_RESERVE);
4447 	if (error == 0)
4448 		(void)vtnet_txq_notify(txq);
4449 	return (error);
4450 }
4451 
4452 static int
4453 vtnet_debugnet_poll(if_t ifp, int count)
4454 {
4455 	struct vtnet_softc *sc;
4456 	int i;
4457 
4458 	sc = if_getsoftc(ifp);
4459 	if ((if_getdrvflags(ifp) & (IFF_DRV_RUNNING | IFF_DRV_OACTIVE)) !=
4460 	    IFF_DRV_RUNNING)
4461 		return (EBUSY);
4462 
4463 	(void)vtnet_txq_eof(&sc->vtnet_txqs[0]);
4464 	for (i = 0; i < sc->vtnet_act_vq_pairs; i++)
4465 		(void)vtnet_rxq_eof(&sc->vtnet_rxqs[i]);
4466 	return (0);
4467 }
4468 #endif /* DEBUGNET */
4469