xref: /freebsd/sys/dev/virtio/network/if_vtnet.c (revision 15f0b8c3)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2011, Bryan Venteicher <bryanv@FreeBSD.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice unmodified, this list of conditions, and the following
12  *    disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 /* Driver for VirtIO network devices. */
30 
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
33 
34 #include <sys/param.h>
35 #include <sys/eventhandler.h>
36 #include <sys/systm.h>
37 #include <sys/kernel.h>
38 #include <sys/sockio.h>
39 #include <sys/malloc.h>
40 #include <sys/mbuf.h>
41 #include <sys/module.h>
42 #include <sys/msan.h>
43 #include <sys/socket.h>
44 #include <sys/sysctl.h>
45 #include <sys/random.h>
46 #include <sys/sglist.h>
47 #include <sys/lock.h>
48 #include <sys/mutex.h>
49 #include <sys/taskqueue.h>
50 #include <sys/smp.h>
51 #include <machine/smp.h>
52 
53 #include <vm/uma.h>
54 
55 #include <net/debugnet.h>
56 #include <net/ethernet.h>
57 #include <net/pfil.h>
58 #include <net/if.h>
59 #include <net/if_var.h>
60 #include <net/if_arp.h>
61 #include <net/if_dl.h>
62 #include <net/if_types.h>
63 #include <net/if_media.h>
64 #include <net/if_vlan_var.h>
65 
66 #include <net/bpf.h>
67 
68 #include <netinet/in_systm.h>
69 #include <netinet/in.h>
70 #include <netinet/ip.h>
71 #include <netinet/ip6.h>
72 #include <netinet6/ip6_var.h>
73 #include <netinet/udp.h>
74 #include <netinet/tcp.h>
75 #include <netinet/tcp_lro.h>
76 
77 #include <machine/bus.h>
78 #include <machine/resource.h>
79 #include <sys/bus.h>
80 #include <sys/rman.h>
81 
82 #include <dev/virtio/virtio.h>
83 #include <dev/virtio/virtqueue.h>
84 #include <dev/virtio/network/virtio_net.h>
85 #include <dev/virtio/network/if_vtnetvar.h>
86 #include "virtio_if.h"
87 
88 #include "opt_inet.h"
89 #include "opt_inet6.h"
90 
91 #if defined(INET) || defined(INET6)
92 #include <machine/in_cksum.h>
93 #endif
94 
95 static int	vtnet_modevent(module_t, int, void *);
96 
97 static int	vtnet_probe(device_t);
98 static int	vtnet_attach(device_t);
99 static int	vtnet_detach(device_t);
100 static int	vtnet_suspend(device_t);
101 static int	vtnet_resume(device_t);
102 static int	vtnet_shutdown(device_t);
103 static int	vtnet_attach_completed(device_t);
104 static int	vtnet_config_change(device_t);
105 
106 static int	vtnet_negotiate_features(struct vtnet_softc *);
107 static int	vtnet_setup_features(struct vtnet_softc *);
108 static int	vtnet_init_rxq(struct vtnet_softc *, int);
109 static int	vtnet_init_txq(struct vtnet_softc *, int);
110 static int	vtnet_alloc_rxtx_queues(struct vtnet_softc *);
111 static void	vtnet_free_rxtx_queues(struct vtnet_softc *);
112 static int	vtnet_alloc_rx_filters(struct vtnet_softc *);
113 static void	vtnet_free_rx_filters(struct vtnet_softc *);
114 static int	vtnet_alloc_virtqueues(struct vtnet_softc *);
115 static int	vtnet_alloc_interface(struct vtnet_softc *);
116 static int	vtnet_setup_interface(struct vtnet_softc *);
117 static int	vtnet_ioctl_mtu(struct vtnet_softc *, u_int);
118 static int	vtnet_ioctl_ifflags(struct vtnet_softc *);
119 static int	vtnet_ioctl_multi(struct vtnet_softc *);
120 static int	vtnet_ioctl_ifcap(struct vtnet_softc *, struct ifreq *);
121 static int	vtnet_ioctl(if_t, u_long, caddr_t);
122 static uint64_t	vtnet_get_counter(if_t, ift_counter);
123 
124 static int	vtnet_rxq_populate(struct vtnet_rxq *);
125 static void	vtnet_rxq_free_mbufs(struct vtnet_rxq *);
126 static struct mbuf *
127 		vtnet_rx_alloc_buf(struct vtnet_softc *, int , struct mbuf **);
128 static int	vtnet_rxq_replace_lro_nomrg_buf(struct vtnet_rxq *,
129 		    struct mbuf *, int);
130 static int	vtnet_rxq_replace_buf(struct vtnet_rxq *, struct mbuf *, int);
131 static int	vtnet_rxq_enqueue_buf(struct vtnet_rxq *, struct mbuf *);
132 static int	vtnet_rxq_new_buf(struct vtnet_rxq *);
133 static int	vtnet_rxq_csum_needs_csum(struct vtnet_rxq *, struct mbuf *,
134 		     uint16_t, int, struct virtio_net_hdr *);
135 static int	vtnet_rxq_csum_data_valid(struct vtnet_rxq *, struct mbuf *,
136 		     uint16_t, int, struct virtio_net_hdr *);
137 static int	vtnet_rxq_csum(struct vtnet_rxq *, struct mbuf *,
138 		     struct virtio_net_hdr *);
139 static void	vtnet_rxq_discard_merged_bufs(struct vtnet_rxq *, int);
140 static void	vtnet_rxq_discard_buf(struct vtnet_rxq *, struct mbuf *);
141 static int	vtnet_rxq_merged_eof(struct vtnet_rxq *, struct mbuf *, int);
142 static void	vtnet_rxq_input(struct vtnet_rxq *, struct mbuf *,
143 		    struct virtio_net_hdr *);
144 static int	vtnet_rxq_eof(struct vtnet_rxq *);
145 static void	vtnet_rx_vq_process(struct vtnet_rxq *rxq, int tries);
146 static void	vtnet_rx_vq_intr(void *);
147 static void	vtnet_rxq_tq_intr(void *, int);
148 
149 static int	vtnet_txq_intr_threshold(struct vtnet_txq *);
150 static int	vtnet_txq_below_threshold(struct vtnet_txq *);
151 static int	vtnet_txq_notify(struct vtnet_txq *);
152 static void	vtnet_txq_free_mbufs(struct vtnet_txq *);
153 static int	vtnet_txq_offload_ctx(struct vtnet_txq *, struct mbuf *,
154 		    int *, int *, int *);
155 static int	vtnet_txq_offload_tso(struct vtnet_txq *, struct mbuf *, int,
156 		    int, struct virtio_net_hdr *);
157 static struct mbuf *
158 		vtnet_txq_offload(struct vtnet_txq *, struct mbuf *,
159 		    struct virtio_net_hdr *);
160 static int	vtnet_txq_enqueue_buf(struct vtnet_txq *, struct mbuf **,
161 		    struct vtnet_tx_header *);
162 static int	vtnet_txq_encap(struct vtnet_txq *, struct mbuf **, int);
163 #ifdef VTNET_LEGACY_TX
164 static void	vtnet_start_locked(struct vtnet_txq *, if_t);
165 static void	vtnet_start(if_t);
166 #else
167 static int	vtnet_txq_mq_start_locked(struct vtnet_txq *, struct mbuf *);
168 static int	vtnet_txq_mq_start(if_t, struct mbuf *);
169 static void	vtnet_txq_tq_deferred(void *, int);
170 #endif
171 static void	vtnet_txq_start(struct vtnet_txq *);
172 static void	vtnet_txq_tq_intr(void *, int);
173 static int	vtnet_txq_eof(struct vtnet_txq *);
174 static void	vtnet_tx_vq_intr(void *);
175 static void	vtnet_tx_start_all(struct vtnet_softc *);
176 
177 #ifndef VTNET_LEGACY_TX
178 static void	vtnet_qflush(if_t);
179 #endif
180 
181 static int	vtnet_watchdog(struct vtnet_txq *);
182 static void	vtnet_accum_stats(struct vtnet_softc *,
183 		    struct vtnet_rxq_stats *, struct vtnet_txq_stats *);
184 static void	vtnet_tick(void *);
185 
186 static void	vtnet_start_taskqueues(struct vtnet_softc *);
187 static void	vtnet_free_taskqueues(struct vtnet_softc *);
188 static void	vtnet_drain_taskqueues(struct vtnet_softc *);
189 
190 static void	vtnet_drain_rxtx_queues(struct vtnet_softc *);
191 static void	vtnet_stop_rendezvous(struct vtnet_softc *);
192 static void	vtnet_stop(struct vtnet_softc *);
193 static int	vtnet_virtio_reinit(struct vtnet_softc *);
194 static void	vtnet_init_rx_filters(struct vtnet_softc *);
195 static int	vtnet_init_rx_queues(struct vtnet_softc *);
196 static int	vtnet_init_tx_queues(struct vtnet_softc *);
197 static int	vtnet_init_rxtx_queues(struct vtnet_softc *);
198 static void	vtnet_set_active_vq_pairs(struct vtnet_softc *);
199 static void	vtnet_update_rx_offloads(struct vtnet_softc *);
200 static int	vtnet_reinit(struct vtnet_softc *);
201 static void	vtnet_init_locked(struct vtnet_softc *, int);
202 static void	vtnet_init(void *);
203 
204 static void	vtnet_free_ctrl_vq(struct vtnet_softc *);
205 static void	vtnet_exec_ctrl_cmd(struct vtnet_softc *, void *,
206 		    struct sglist *, int, int);
207 static int	vtnet_ctrl_mac_cmd(struct vtnet_softc *, uint8_t *);
208 static int	vtnet_ctrl_guest_offloads(struct vtnet_softc *, uint64_t);
209 static int	vtnet_ctrl_mq_cmd(struct vtnet_softc *, uint16_t);
210 static int	vtnet_ctrl_rx_cmd(struct vtnet_softc *, uint8_t, bool);
211 static int	vtnet_set_promisc(struct vtnet_softc *, bool);
212 static int	vtnet_set_allmulti(struct vtnet_softc *, bool);
213 static void	vtnet_rx_filter(struct vtnet_softc *);
214 static void	vtnet_rx_filter_mac(struct vtnet_softc *);
215 static int	vtnet_exec_vlan_filter(struct vtnet_softc *, int, uint16_t);
216 static void	vtnet_rx_filter_vlan(struct vtnet_softc *);
217 static void	vtnet_update_vlan_filter(struct vtnet_softc *, int, uint16_t);
218 static void	vtnet_register_vlan(void *, if_t, uint16_t);
219 static void	vtnet_unregister_vlan(void *, if_t, uint16_t);
220 
221 static void	vtnet_update_speed_duplex(struct vtnet_softc *);
222 static int	vtnet_is_link_up(struct vtnet_softc *);
223 static void	vtnet_update_link_status(struct vtnet_softc *);
224 static int	vtnet_ifmedia_upd(if_t);
225 static void	vtnet_ifmedia_sts(if_t, struct ifmediareq *);
226 static void	vtnet_get_macaddr(struct vtnet_softc *);
227 static void	vtnet_set_macaddr(struct vtnet_softc *);
228 static void	vtnet_attached_set_macaddr(struct vtnet_softc *);
229 static void	vtnet_vlan_tag_remove(struct mbuf *);
230 static void	vtnet_set_rx_process_limit(struct vtnet_softc *);
231 
232 static void	vtnet_setup_rxq_sysctl(struct sysctl_ctx_list *,
233 		    struct sysctl_oid_list *, struct vtnet_rxq *);
234 static void	vtnet_setup_txq_sysctl(struct sysctl_ctx_list *,
235 		    struct sysctl_oid_list *, struct vtnet_txq *);
236 static void	vtnet_setup_queue_sysctl(struct vtnet_softc *);
237 static void	vtnet_load_tunables(struct vtnet_softc *);
238 static void	vtnet_setup_sysctl(struct vtnet_softc *);
239 
240 static int	vtnet_rxq_enable_intr(struct vtnet_rxq *);
241 static void	vtnet_rxq_disable_intr(struct vtnet_rxq *);
242 static int	vtnet_txq_enable_intr(struct vtnet_txq *);
243 static void	vtnet_txq_disable_intr(struct vtnet_txq *);
244 static void	vtnet_enable_rx_interrupts(struct vtnet_softc *);
245 static void	vtnet_enable_tx_interrupts(struct vtnet_softc *);
246 static void	vtnet_enable_interrupts(struct vtnet_softc *);
247 static void	vtnet_disable_rx_interrupts(struct vtnet_softc *);
248 static void	vtnet_disable_tx_interrupts(struct vtnet_softc *);
249 static void	vtnet_disable_interrupts(struct vtnet_softc *);
250 
251 static int	vtnet_tunable_int(struct vtnet_softc *, const char *, int);
252 
253 DEBUGNET_DEFINE(vtnet);
254 
255 #define vtnet_htog16(_sc, _val)	virtio_htog16(vtnet_modern(_sc), _val)
256 #define vtnet_htog32(_sc, _val)	virtio_htog32(vtnet_modern(_sc), _val)
257 #define vtnet_htog64(_sc, _val)	virtio_htog64(vtnet_modern(_sc), _val)
258 #define vtnet_gtoh16(_sc, _val)	virtio_gtoh16(vtnet_modern(_sc), _val)
259 #define vtnet_gtoh32(_sc, _val)	virtio_gtoh32(vtnet_modern(_sc), _val)
260 #define vtnet_gtoh64(_sc, _val)	virtio_gtoh64(vtnet_modern(_sc), _val)
261 
262 /* Tunables. */
263 static SYSCTL_NODE(_hw, OID_AUTO, vtnet, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
264     "VirtIO Net driver parameters");
265 
266 static int vtnet_csum_disable = 0;
267 SYSCTL_INT(_hw_vtnet, OID_AUTO, csum_disable, CTLFLAG_RDTUN,
268     &vtnet_csum_disable, 0, "Disables receive and send checksum offload");
269 
270 static int vtnet_fixup_needs_csum = 0;
271 SYSCTL_INT(_hw_vtnet, OID_AUTO, fixup_needs_csum, CTLFLAG_RDTUN,
272     &vtnet_fixup_needs_csum, 0,
273     "Calculate valid checksum for NEEDS_CSUM packets");
274 
275 static int vtnet_tso_disable = 0;
276 SYSCTL_INT(_hw_vtnet, OID_AUTO, tso_disable, CTLFLAG_RDTUN,
277     &vtnet_tso_disable, 0, "Disables TSO");
278 
279 static int vtnet_lro_disable = 0;
280 SYSCTL_INT(_hw_vtnet, OID_AUTO, lro_disable, CTLFLAG_RDTUN,
281     &vtnet_lro_disable, 0, "Disables hardware LRO");
282 
283 static int vtnet_mq_disable = 0;
284 SYSCTL_INT(_hw_vtnet, OID_AUTO, mq_disable, CTLFLAG_RDTUN,
285     &vtnet_mq_disable, 0, "Disables multiqueue support");
286 
287 static int vtnet_mq_max_pairs = VTNET_MAX_QUEUE_PAIRS;
288 SYSCTL_INT(_hw_vtnet, OID_AUTO, mq_max_pairs, CTLFLAG_RDTUN,
289     &vtnet_mq_max_pairs, 0, "Maximum number of multiqueue pairs");
290 
291 static int vtnet_tso_maxlen = IP_MAXPACKET;
292 SYSCTL_INT(_hw_vtnet, OID_AUTO, tso_maxlen, CTLFLAG_RDTUN,
293     &vtnet_tso_maxlen, 0, "TSO burst limit");
294 
295 static int vtnet_rx_process_limit = 1024;
296 SYSCTL_INT(_hw_vtnet, OID_AUTO, rx_process_limit, CTLFLAG_RDTUN,
297     &vtnet_rx_process_limit, 0,
298     "Number of RX segments processed in one pass");
299 
300 static int vtnet_lro_entry_count = 128;
301 SYSCTL_INT(_hw_vtnet, OID_AUTO, lro_entry_count, CTLFLAG_RDTUN,
302     &vtnet_lro_entry_count, 0, "Software LRO entry count");
303 
304 /* Enable sorted LRO, and the depth of the mbuf queue. */
305 static int vtnet_lro_mbufq_depth = 0;
306 SYSCTL_UINT(_hw_vtnet, OID_AUTO, lro_mbufq_depth, CTLFLAG_RDTUN,
307     &vtnet_lro_mbufq_depth, 0, "Depth of software LRO mbuf queue");
308 
309 static uma_zone_t vtnet_tx_header_zone;
310 
311 static struct virtio_feature_desc vtnet_feature_desc[] = {
312 	{ VIRTIO_NET_F_CSUM,			"TxChecksum"		},
313 	{ VIRTIO_NET_F_GUEST_CSUM,		"RxChecksum"		},
314 	{ VIRTIO_NET_F_CTRL_GUEST_OFFLOADS,	"CtrlRxOffloads"	},
315 	{ VIRTIO_NET_F_MAC,			"MAC"			},
316 	{ VIRTIO_NET_F_GSO,			"TxGSO"			},
317 	{ VIRTIO_NET_F_GUEST_TSO4,		"RxLROv4"		},
318 	{ VIRTIO_NET_F_GUEST_TSO6,		"RxLROv6"		},
319 	{ VIRTIO_NET_F_GUEST_ECN,		"RxLROECN"		},
320 	{ VIRTIO_NET_F_GUEST_UFO,		"RxUFO"			},
321 	{ VIRTIO_NET_F_HOST_TSO4,		"TxTSOv4"		},
322 	{ VIRTIO_NET_F_HOST_TSO6,		"TxTSOv6"		},
323 	{ VIRTIO_NET_F_HOST_ECN,		"TxTSOECN"		},
324 	{ VIRTIO_NET_F_HOST_UFO,		"TxUFO"			},
325 	{ VIRTIO_NET_F_MRG_RXBUF,		"MrgRxBuf"		},
326 	{ VIRTIO_NET_F_STATUS,			"Status"		},
327 	{ VIRTIO_NET_F_CTRL_VQ,			"CtrlVq"		},
328 	{ VIRTIO_NET_F_CTRL_RX,			"CtrlRxMode"		},
329 	{ VIRTIO_NET_F_CTRL_VLAN,		"CtrlVLANFilter"	},
330 	{ VIRTIO_NET_F_CTRL_RX_EXTRA,		"CtrlRxModeExtra"	},
331 	{ VIRTIO_NET_F_GUEST_ANNOUNCE,		"GuestAnnounce"		},
332 	{ VIRTIO_NET_F_MQ,			"Multiqueue"		},
333 	{ VIRTIO_NET_F_CTRL_MAC_ADDR,		"CtrlMacAddr"		},
334 	{ VIRTIO_NET_F_SPEED_DUPLEX,		"SpeedDuplex"		},
335 
336 	{ 0, NULL }
337 };
338 
339 static device_method_t vtnet_methods[] = {
340 	/* Device methods. */
341 	DEVMETHOD(device_probe,			vtnet_probe),
342 	DEVMETHOD(device_attach,		vtnet_attach),
343 	DEVMETHOD(device_detach,		vtnet_detach),
344 	DEVMETHOD(device_suspend,		vtnet_suspend),
345 	DEVMETHOD(device_resume,		vtnet_resume),
346 	DEVMETHOD(device_shutdown,		vtnet_shutdown),
347 
348 	/* VirtIO methods. */
349 	DEVMETHOD(virtio_attach_completed,	vtnet_attach_completed),
350 	DEVMETHOD(virtio_config_change,		vtnet_config_change),
351 
352 	DEVMETHOD_END
353 };
354 
355 #ifdef DEV_NETMAP
356 #include <dev/netmap/if_vtnet_netmap.h>
357 #endif
358 
359 static driver_t vtnet_driver = {
360     .name = "vtnet",
361     .methods = vtnet_methods,
362     .size = sizeof(struct vtnet_softc)
363 };
364 VIRTIO_DRIVER_MODULE(vtnet, vtnet_driver, vtnet_modevent, NULL);
365 MODULE_VERSION(vtnet, 1);
366 MODULE_DEPEND(vtnet, virtio, 1, 1, 1);
367 #ifdef DEV_NETMAP
368 MODULE_DEPEND(vtnet, netmap, 1, 1, 1);
369 #endif
370 
371 VIRTIO_SIMPLE_PNPINFO(vtnet, VIRTIO_ID_NETWORK, "VirtIO Networking Adapter");
372 
373 static int
374 vtnet_modevent(module_t mod __unused, int type, void *unused __unused)
375 {
376 	int error = 0;
377 	static int loaded = 0;
378 
379 	switch (type) {
380 	case MOD_LOAD:
381 		if (loaded++ == 0) {
382 			vtnet_tx_header_zone = uma_zcreate("vtnet_tx_hdr",
383 				sizeof(struct vtnet_tx_header),
384 				NULL, NULL, NULL, NULL, 0, 0);
385 #ifdef DEBUGNET
386 			/*
387 			 * We need to allocate from this zone in the transmit path, so ensure
388 			 * that we have at least one item per header available.
389 			 * XXX add a separate zone like we do for mbufs? otherwise we may alloc
390 			 * buckets
391 			 */
392 			uma_zone_reserve(vtnet_tx_header_zone, DEBUGNET_MAX_IN_FLIGHT * 2);
393 			uma_prealloc(vtnet_tx_header_zone, DEBUGNET_MAX_IN_FLIGHT * 2);
394 #endif
395 		}
396 		break;
397 	case MOD_QUIESCE:
398 		if (uma_zone_get_cur(vtnet_tx_header_zone) > 0)
399 			error = EBUSY;
400 		break;
401 	case MOD_UNLOAD:
402 		if (--loaded == 0) {
403 			uma_zdestroy(vtnet_tx_header_zone);
404 			vtnet_tx_header_zone = NULL;
405 		}
406 		break;
407 	case MOD_SHUTDOWN:
408 		break;
409 	default:
410 		error = EOPNOTSUPP;
411 		break;
412 	}
413 
414 	return (error);
415 }
416 
417 static int
418 vtnet_probe(device_t dev)
419 {
420 	return (VIRTIO_SIMPLE_PROBE(dev, vtnet));
421 }
422 
423 static int
424 vtnet_attach(device_t dev)
425 {
426 	struct vtnet_softc *sc;
427 	int error;
428 
429 	sc = device_get_softc(dev);
430 	sc->vtnet_dev = dev;
431 	virtio_set_feature_desc(dev, vtnet_feature_desc);
432 
433 	VTNET_CORE_LOCK_INIT(sc);
434 	callout_init_mtx(&sc->vtnet_tick_ch, VTNET_CORE_MTX(sc), 0);
435 	vtnet_load_tunables(sc);
436 
437 	error = vtnet_alloc_interface(sc);
438 	if (error) {
439 		device_printf(dev, "cannot allocate interface\n");
440 		goto fail;
441 	}
442 
443 	vtnet_setup_sysctl(sc);
444 
445 	error = vtnet_setup_features(sc);
446 	if (error) {
447 		device_printf(dev, "cannot setup features\n");
448 		goto fail;
449 	}
450 
451 	error = vtnet_alloc_rx_filters(sc);
452 	if (error) {
453 		device_printf(dev, "cannot allocate Rx filters\n");
454 		goto fail;
455 	}
456 
457 	error = vtnet_alloc_rxtx_queues(sc);
458 	if (error) {
459 		device_printf(dev, "cannot allocate queues\n");
460 		goto fail;
461 	}
462 
463 	error = vtnet_alloc_virtqueues(sc);
464 	if (error) {
465 		device_printf(dev, "cannot allocate virtqueues\n");
466 		goto fail;
467 	}
468 
469 	error = vtnet_setup_interface(sc);
470 	if (error) {
471 		device_printf(dev, "cannot setup interface\n");
472 		goto fail;
473 	}
474 
475 	error = virtio_setup_intr(dev, INTR_TYPE_NET);
476 	if (error) {
477 		device_printf(dev, "cannot setup interrupts\n");
478 		ether_ifdetach(sc->vtnet_ifp);
479 		goto fail;
480 	}
481 
482 #ifdef DEV_NETMAP
483 	vtnet_netmap_attach(sc);
484 #endif
485 	vtnet_start_taskqueues(sc);
486 
487 fail:
488 	if (error)
489 		vtnet_detach(dev);
490 
491 	return (error);
492 }
493 
494 static int
495 vtnet_detach(device_t dev)
496 {
497 	struct vtnet_softc *sc;
498 	if_t ifp;
499 
500 	sc = device_get_softc(dev);
501 	ifp = sc->vtnet_ifp;
502 
503 	if (device_is_attached(dev)) {
504 		VTNET_CORE_LOCK(sc);
505 		vtnet_stop(sc);
506 		VTNET_CORE_UNLOCK(sc);
507 
508 		callout_drain(&sc->vtnet_tick_ch);
509 		vtnet_drain_taskqueues(sc);
510 
511 		ether_ifdetach(ifp);
512 	}
513 
514 #ifdef DEV_NETMAP
515 	netmap_detach(ifp);
516 #endif
517 
518 	if (sc->vtnet_pfil != NULL) {
519 		pfil_head_unregister(sc->vtnet_pfil);
520 		sc->vtnet_pfil = NULL;
521 	}
522 
523 	vtnet_free_taskqueues(sc);
524 
525 	if (sc->vtnet_vlan_attach != NULL) {
526 		EVENTHANDLER_DEREGISTER(vlan_config, sc->vtnet_vlan_attach);
527 		sc->vtnet_vlan_attach = NULL;
528 	}
529 	if (sc->vtnet_vlan_detach != NULL) {
530 		EVENTHANDLER_DEREGISTER(vlan_unconfig, sc->vtnet_vlan_detach);
531 		sc->vtnet_vlan_detach = NULL;
532 	}
533 
534 	ifmedia_removeall(&sc->vtnet_media);
535 
536 	if (ifp != NULL) {
537 		if_free(ifp);
538 		sc->vtnet_ifp = NULL;
539 	}
540 
541 	vtnet_free_rxtx_queues(sc);
542 	vtnet_free_rx_filters(sc);
543 
544 	if (sc->vtnet_ctrl_vq != NULL)
545 		vtnet_free_ctrl_vq(sc);
546 
547 	VTNET_CORE_LOCK_DESTROY(sc);
548 
549 	return (0);
550 }
551 
552 static int
553 vtnet_suspend(device_t dev)
554 {
555 	struct vtnet_softc *sc;
556 
557 	sc = device_get_softc(dev);
558 
559 	VTNET_CORE_LOCK(sc);
560 	vtnet_stop(sc);
561 	sc->vtnet_flags |= VTNET_FLAG_SUSPENDED;
562 	VTNET_CORE_UNLOCK(sc);
563 
564 	return (0);
565 }
566 
567 static int
568 vtnet_resume(device_t dev)
569 {
570 	struct vtnet_softc *sc;
571 	if_t ifp;
572 
573 	sc = device_get_softc(dev);
574 	ifp = sc->vtnet_ifp;
575 
576 	VTNET_CORE_LOCK(sc);
577 	if (if_getflags(ifp) & IFF_UP)
578 		vtnet_init_locked(sc, 0);
579 	sc->vtnet_flags &= ~VTNET_FLAG_SUSPENDED;
580 	VTNET_CORE_UNLOCK(sc);
581 
582 	return (0);
583 }
584 
585 static int
586 vtnet_shutdown(device_t dev)
587 {
588 	/*
589 	 * Suspend already does all of what we need to
590 	 * do here; we just never expect to be resumed.
591 	 */
592 	return (vtnet_suspend(dev));
593 }
594 
595 static int
596 vtnet_attach_completed(device_t dev)
597 {
598 	struct vtnet_softc *sc;
599 
600 	sc = device_get_softc(dev);
601 
602 	VTNET_CORE_LOCK(sc);
603 	vtnet_attached_set_macaddr(sc);
604 	VTNET_CORE_UNLOCK(sc);
605 
606 	return (0);
607 }
608 
609 static int
610 vtnet_config_change(device_t dev)
611 {
612 	struct vtnet_softc *sc;
613 
614 	sc = device_get_softc(dev);
615 
616 	VTNET_CORE_LOCK(sc);
617 	vtnet_update_link_status(sc);
618 	if (sc->vtnet_link_active != 0)
619 		vtnet_tx_start_all(sc);
620 	VTNET_CORE_UNLOCK(sc);
621 
622 	return (0);
623 }
624 
625 static int
626 vtnet_negotiate_features(struct vtnet_softc *sc)
627 {
628 	device_t dev;
629 	uint64_t features, negotiated_features;
630 	int no_csum;
631 
632 	dev = sc->vtnet_dev;
633 	features = virtio_bus_is_modern(dev) ? VTNET_MODERN_FEATURES :
634 	    VTNET_LEGACY_FEATURES;
635 
636 	/*
637 	 * TSO and LRO are only available when their corresponding checksum
638 	 * offload feature is also negotiated.
639 	 */
640 	no_csum = vtnet_tunable_int(sc, "csum_disable", vtnet_csum_disable);
641 	if (no_csum)
642 		features &= ~(VIRTIO_NET_F_CSUM | VIRTIO_NET_F_GUEST_CSUM);
643 	if (no_csum || vtnet_tunable_int(sc, "tso_disable", vtnet_tso_disable))
644 		features &= ~VTNET_TSO_FEATURES;
645 	if (no_csum || vtnet_tunable_int(sc, "lro_disable", vtnet_lro_disable))
646 		features &= ~VTNET_LRO_FEATURES;
647 
648 #ifndef VTNET_LEGACY_TX
649 	if (vtnet_tunable_int(sc, "mq_disable", vtnet_mq_disable))
650 		features &= ~VIRTIO_NET_F_MQ;
651 #else
652 	features &= ~VIRTIO_NET_F_MQ;
653 #endif
654 
655 	negotiated_features = virtio_negotiate_features(dev, features);
656 
657 	if (virtio_with_feature(dev, VIRTIO_NET_F_MTU)) {
658 		uint16_t mtu;
659 
660 		mtu = virtio_read_dev_config_2(dev,
661 		    offsetof(struct virtio_net_config, mtu));
662 		if (mtu < VTNET_MIN_MTU /* || mtu > VTNET_MAX_MTU */) {
663 			device_printf(dev, "Invalid MTU value: %d. "
664 			    "MTU feature disabled.\n", mtu);
665 			features &= ~VIRTIO_NET_F_MTU;
666 			negotiated_features =
667 			    virtio_negotiate_features(dev, features);
668 		}
669 	}
670 
671 	if (virtio_with_feature(dev, VIRTIO_NET_F_MQ)) {
672 		uint16_t npairs;
673 
674 		npairs = virtio_read_dev_config_2(dev,
675 		    offsetof(struct virtio_net_config, max_virtqueue_pairs));
676 		if (npairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
677 		    npairs > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX) {
678 			device_printf(dev, "Invalid max_virtqueue_pairs value: "
679 			    "%d. Multiqueue feature disabled.\n", npairs);
680 			features &= ~VIRTIO_NET_F_MQ;
681 			negotiated_features =
682 			    virtio_negotiate_features(dev, features);
683 		}
684 	}
685 
686 	if (virtio_with_feature(dev, VTNET_LRO_FEATURES) &&
687 	    virtio_with_feature(dev, VIRTIO_NET_F_MRG_RXBUF) == 0) {
688 		/*
689 		 * LRO without mergeable buffers requires special care. This
690 		 * is not ideal because every receive buffer must be large
691 		 * enough to hold the maximum TCP packet, the Ethernet header,
692 		 * and the header. This requires up to 34 descriptors with
693 		 * MCLBYTES clusters. If we do not have indirect descriptors,
694 		 * LRO is disabled since the virtqueue will not contain very
695 		 * many receive buffers.
696 		 */
697 		if (!virtio_with_feature(dev, VIRTIO_RING_F_INDIRECT_DESC)) {
698 			device_printf(dev,
699 			    "Host LRO disabled since both mergeable buffers "
700 			    "and indirect descriptors were not negotiated\n");
701 			features &= ~VTNET_LRO_FEATURES;
702 			negotiated_features =
703 			    virtio_negotiate_features(dev, features);
704 		} else
705 			sc->vtnet_flags |= VTNET_FLAG_LRO_NOMRG;
706 	}
707 
708 	sc->vtnet_features = negotiated_features;
709 	sc->vtnet_negotiated_features = negotiated_features;
710 
711 	return (virtio_finalize_features(dev));
712 }
713 
714 static int
715 vtnet_setup_features(struct vtnet_softc *sc)
716 {
717 	device_t dev;
718 	int error;
719 
720 	dev = sc->vtnet_dev;
721 
722 	error = vtnet_negotiate_features(sc);
723 	if (error)
724 		return (error);
725 
726 	if (virtio_with_feature(dev, VIRTIO_F_VERSION_1))
727 		sc->vtnet_flags |= VTNET_FLAG_MODERN;
728 	if (virtio_with_feature(dev, VIRTIO_RING_F_INDIRECT_DESC))
729 		sc->vtnet_flags |= VTNET_FLAG_INDIRECT;
730 	if (virtio_with_feature(dev, VIRTIO_RING_F_EVENT_IDX))
731 		sc->vtnet_flags |= VTNET_FLAG_EVENT_IDX;
732 
733 	if (virtio_with_feature(dev, VIRTIO_NET_F_MAC)) {
734 		/* This feature should always be negotiated. */
735 		sc->vtnet_flags |= VTNET_FLAG_MAC;
736 	}
737 
738 	if (virtio_with_feature(dev, VIRTIO_NET_F_MTU)) {
739 		sc->vtnet_max_mtu = virtio_read_dev_config_2(dev,
740 		    offsetof(struct virtio_net_config, mtu));
741 	} else
742 		sc->vtnet_max_mtu = VTNET_MAX_MTU;
743 
744 	if (virtio_with_feature(dev, VIRTIO_NET_F_MRG_RXBUF)) {
745 		sc->vtnet_flags |= VTNET_FLAG_MRG_RXBUFS;
746 		sc->vtnet_hdr_size = sizeof(struct virtio_net_hdr_mrg_rxbuf);
747 	} else if (vtnet_modern(sc)) {
748 		/* This is identical to the mergeable header. */
749 		sc->vtnet_hdr_size = sizeof(struct virtio_net_hdr_v1);
750 	} else
751 		sc->vtnet_hdr_size = sizeof(struct virtio_net_hdr);
752 
753 	if (vtnet_modern(sc) || sc->vtnet_flags & VTNET_FLAG_MRG_RXBUFS)
754 		sc->vtnet_rx_nsegs = VTNET_RX_SEGS_HDR_INLINE;
755 	else if (sc->vtnet_flags & VTNET_FLAG_LRO_NOMRG)
756 		sc->vtnet_rx_nsegs = VTNET_RX_SEGS_LRO_NOMRG;
757 	else
758 		sc->vtnet_rx_nsegs = VTNET_RX_SEGS_HDR_SEPARATE;
759 
760 	/*
761 	 * Favor "hardware" LRO if negotiated, but support software LRO as
762 	 * a fallback; there is usually little benefit (or worse) with both.
763 	 */
764 	if (virtio_with_feature(dev, VIRTIO_NET_F_GUEST_TSO4) == 0 &&
765 	    virtio_with_feature(dev, VIRTIO_NET_F_GUEST_TSO6) == 0)
766 		sc->vtnet_flags |= VTNET_FLAG_SW_LRO;
767 
768 	if (virtio_with_feature(dev, VIRTIO_NET_F_GSO) ||
769 	    virtio_with_feature(dev, VIRTIO_NET_F_HOST_TSO4) ||
770 	    virtio_with_feature(dev, VIRTIO_NET_F_HOST_TSO6))
771 		sc->vtnet_tx_nsegs = VTNET_TX_SEGS_MAX;
772 	else
773 		sc->vtnet_tx_nsegs = VTNET_TX_SEGS_MIN;
774 
775 	sc->vtnet_req_vq_pairs = 1;
776 	sc->vtnet_max_vq_pairs = 1;
777 
778 	if (virtio_with_feature(dev, VIRTIO_NET_F_CTRL_VQ)) {
779 		sc->vtnet_flags |= VTNET_FLAG_CTRL_VQ;
780 
781 		if (virtio_with_feature(dev, VIRTIO_NET_F_CTRL_RX))
782 			sc->vtnet_flags |= VTNET_FLAG_CTRL_RX;
783 		if (virtio_with_feature(dev, VIRTIO_NET_F_CTRL_VLAN))
784 			sc->vtnet_flags |= VTNET_FLAG_VLAN_FILTER;
785 		if (virtio_with_feature(dev, VIRTIO_NET_F_CTRL_MAC_ADDR))
786 			sc->vtnet_flags |= VTNET_FLAG_CTRL_MAC;
787 
788 		if (virtio_with_feature(dev, VIRTIO_NET_F_MQ)) {
789 			sc->vtnet_max_vq_pairs = virtio_read_dev_config_2(dev,
790 			    offsetof(struct virtio_net_config,
791 			    max_virtqueue_pairs));
792 		}
793 	}
794 
795 	if (sc->vtnet_max_vq_pairs > 1) {
796 		int req;
797 
798 		/*
799 		 * Limit the maximum number of requested queue pairs to the
800 		 * number of CPUs and the configured maximum.
801 		 */
802 		req = vtnet_tunable_int(sc, "mq_max_pairs", vtnet_mq_max_pairs);
803 		if (req < 0)
804 			req = 1;
805 		if (req == 0)
806 			req = mp_ncpus;
807 		if (req > sc->vtnet_max_vq_pairs)
808 			req = sc->vtnet_max_vq_pairs;
809 		if (req > mp_ncpus)
810 			req = mp_ncpus;
811 		if (req > 1) {
812 			sc->vtnet_req_vq_pairs = req;
813 			sc->vtnet_flags |= VTNET_FLAG_MQ;
814 		}
815 	}
816 
817 	return (0);
818 }
819 
820 static int
821 vtnet_init_rxq(struct vtnet_softc *sc, int id)
822 {
823 	struct vtnet_rxq *rxq;
824 
825 	rxq = &sc->vtnet_rxqs[id];
826 
827 	snprintf(rxq->vtnrx_name, sizeof(rxq->vtnrx_name), "%s-rx%d",
828 	    device_get_nameunit(sc->vtnet_dev), id);
829 	mtx_init(&rxq->vtnrx_mtx, rxq->vtnrx_name, NULL, MTX_DEF);
830 
831 	rxq->vtnrx_sc = sc;
832 	rxq->vtnrx_id = id;
833 
834 	rxq->vtnrx_sg = sglist_alloc(sc->vtnet_rx_nsegs, M_NOWAIT);
835 	if (rxq->vtnrx_sg == NULL)
836 		return (ENOMEM);
837 
838 #if defined(INET) || defined(INET6)
839 	if (vtnet_software_lro(sc)) {
840 		if (tcp_lro_init_args(&rxq->vtnrx_lro, sc->vtnet_ifp,
841 		    sc->vtnet_lro_entry_count, sc->vtnet_lro_mbufq_depth) != 0)
842 			return (ENOMEM);
843 	}
844 #endif
845 
846 	NET_TASK_INIT(&rxq->vtnrx_intrtask, 0, vtnet_rxq_tq_intr, rxq);
847 	rxq->vtnrx_tq = taskqueue_create(rxq->vtnrx_name, M_NOWAIT,
848 	    taskqueue_thread_enqueue, &rxq->vtnrx_tq);
849 
850 	return (rxq->vtnrx_tq == NULL ? ENOMEM : 0);
851 }
852 
853 static int
854 vtnet_init_txq(struct vtnet_softc *sc, int id)
855 {
856 	struct vtnet_txq *txq;
857 
858 	txq = &sc->vtnet_txqs[id];
859 
860 	snprintf(txq->vtntx_name, sizeof(txq->vtntx_name), "%s-tx%d",
861 	    device_get_nameunit(sc->vtnet_dev), id);
862 	mtx_init(&txq->vtntx_mtx, txq->vtntx_name, NULL, MTX_DEF);
863 
864 	txq->vtntx_sc = sc;
865 	txq->vtntx_id = id;
866 
867 	txq->vtntx_sg = sglist_alloc(sc->vtnet_tx_nsegs, M_NOWAIT);
868 	if (txq->vtntx_sg == NULL)
869 		return (ENOMEM);
870 
871 #ifndef VTNET_LEGACY_TX
872 	txq->vtntx_br = buf_ring_alloc(VTNET_DEFAULT_BUFRING_SIZE, M_DEVBUF,
873 	    M_NOWAIT, &txq->vtntx_mtx);
874 	if (txq->vtntx_br == NULL)
875 		return (ENOMEM);
876 
877 	TASK_INIT(&txq->vtntx_defrtask, 0, vtnet_txq_tq_deferred, txq);
878 #endif
879 	TASK_INIT(&txq->vtntx_intrtask, 0, vtnet_txq_tq_intr, txq);
880 	txq->vtntx_tq = taskqueue_create(txq->vtntx_name, M_NOWAIT,
881 	    taskqueue_thread_enqueue, &txq->vtntx_tq);
882 	if (txq->vtntx_tq == NULL)
883 		return (ENOMEM);
884 
885 	return (0);
886 }
887 
888 static int
889 vtnet_alloc_rxtx_queues(struct vtnet_softc *sc)
890 {
891 	int i, npairs, error;
892 
893 	npairs = sc->vtnet_max_vq_pairs;
894 
895 	sc->vtnet_rxqs = malloc(sizeof(struct vtnet_rxq) * npairs, M_DEVBUF,
896 	    M_NOWAIT | M_ZERO);
897 	sc->vtnet_txqs = malloc(sizeof(struct vtnet_txq) * npairs, M_DEVBUF,
898 	    M_NOWAIT | M_ZERO);
899 	if (sc->vtnet_rxqs == NULL || sc->vtnet_txqs == NULL)
900 		return (ENOMEM);
901 
902 	for (i = 0; i < npairs; i++) {
903 		error = vtnet_init_rxq(sc, i);
904 		if (error)
905 			return (error);
906 		error = vtnet_init_txq(sc, i);
907 		if (error)
908 			return (error);
909 	}
910 
911 	vtnet_set_rx_process_limit(sc);
912 	vtnet_setup_queue_sysctl(sc);
913 
914 	return (0);
915 }
916 
917 static void
918 vtnet_destroy_rxq(struct vtnet_rxq *rxq)
919 {
920 
921 	rxq->vtnrx_sc = NULL;
922 	rxq->vtnrx_id = -1;
923 
924 #if defined(INET) || defined(INET6)
925 	tcp_lro_free(&rxq->vtnrx_lro);
926 #endif
927 
928 	if (rxq->vtnrx_sg != NULL) {
929 		sglist_free(rxq->vtnrx_sg);
930 		rxq->vtnrx_sg = NULL;
931 	}
932 
933 	if (mtx_initialized(&rxq->vtnrx_mtx) != 0)
934 		mtx_destroy(&rxq->vtnrx_mtx);
935 }
936 
937 static void
938 vtnet_destroy_txq(struct vtnet_txq *txq)
939 {
940 
941 	txq->vtntx_sc = NULL;
942 	txq->vtntx_id = -1;
943 
944 	if (txq->vtntx_sg != NULL) {
945 		sglist_free(txq->vtntx_sg);
946 		txq->vtntx_sg = NULL;
947 	}
948 
949 #ifndef VTNET_LEGACY_TX
950 	if (txq->vtntx_br != NULL) {
951 		buf_ring_free(txq->vtntx_br, M_DEVBUF);
952 		txq->vtntx_br = NULL;
953 	}
954 #endif
955 
956 	if (mtx_initialized(&txq->vtntx_mtx) != 0)
957 		mtx_destroy(&txq->vtntx_mtx);
958 }
959 
960 static void
961 vtnet_free_rxtx_queues(struct vtnet_softc *sc)
962 {
963 	int i;
964 
965 	if (sc->vtnet_rxqs != NULL) {
966 		for (i = 0; i < sc->vtnet_max_vq_pairs; i++)
967 			vtnet_destroy_rxq(&sc->vtnet_rxqs[i]);
968 		free(sc->vtnet_rxqs, M_DEVBUF);
969 		sc->vtnet_rxqs = NULL;
970 	}
971 
972 	if (sc->vtnet_txqs != NULL) {
973 		for (i = 0; i < sc->vtnet_max_vq_pairs; i++)
974 			vtnet_destroy_txq(&sc->vtnet_txqs[i]);
975 		free(sc->vtnet_txqs, M_DEVBUF);
976 		sc->vtnet_txqs = NULL;
977 	}
978 }
979 
980 static int
981 vtnet_alloc_rx_filters(struct vtnet_softc *sc)
982 {
983 
984 	if (sc->vtnet_flags & VTNET_FLAG_CTRL_RX) {
985 		sc->vtnet_mac_filter = malloc(sizeof(struct vtnet_mac_filter),
986 		    M_DEVBUF, M_NOWAIT | M_ZERO);
987 		if (sc->vtnet_mac_filter == NULL)
988 			return (ENOMEM);
989 	}
990 
991 	if (sc->vtnet_flags & VTNET_FLAG_VLAN_FILTER) {
992 		sc->vtnet_vlan_filter = malloc(sizeof(uint32_t) *
993 		    VTNET_VLAN_FILTER_NWORDS, M_DEVBUF, M_NOWAIT | M_ZERO);
994 		if (sc->vtnet_vlan_filter == NULL)
995 			return (ENOMEM);
996 	}
997 
998 	return (0);
999 }
1000 
1001 static void
1002 vtnet_free_rx_filters(struct vtnet_softc *sc)
1003 {
1004 
1005 	if (sc->vtnet_mac_filter != NULL) {
1006 		free(sc->vtnet_mac_filter, M_DEVBUF);
1007 		sc->vtnet_mac_filter = NULL;
1008 	}
1009 
1010 	if (sc->vtnet_vlan_filter != NULL) {
1011 		free(sc->vtnet_vlan_filter, M_DEVBUF);
1012 		sc->vtnet_vlan_filter = NULL;
1013 	}
1014 }
1015 
1016 static int
1017 vtnet_alloc_virtqueues(struct vtnet_softc *sc)
1018 {
1019 	device_t dev;
1020 	struct vq_alloc_info *info;
1021 	struct vtnet_rxq *rxq;
1022 	struct vtnet_txq *txq;
1023 	int i, idx, flags, nvqs, error;
1024 
1025 	dev = sc->vtnet_dev;
1026 	flags = 0;
1027 
1028 	nvqs = sc->vtnet_max_vq_pairs * 2;
1029 	if (sc->vtnet_flags & VTNET_FLAG_CTRL_VQ)
1030 		nvqs++;
1031 
1032 	info = malloc(sizeof(struct vq_alloc_info) * nvqs, M_TEMP, M_NOWAIT);
1033 	if (info == NULL)
1034 		return (ENOMEM);
1035 
1036 	for (i = 0, idx = 0; i < sc->vtnet_req_vq_pairs; i++, idx += 2) {
1037 		rxq = &sc->vtnet_rxqs[i];
1038 		VQ_ALLOC_INFO_INIT(&info[idx], sc->vtnet_rx_nsegs,
1039 		    vtnet_rx_vq_intr, rxq, &rxq->vtnrx_vq,
1040 		    "%s-rx%d", device_get_nameunit(dev), rxq->vtnrx_id);
1041 
1042 		txq = &sc->vtnet_txqs[i];
1043 		VQ_ALLOC_INFO_INIT(&info[idx+1], sc->vtnet_tx_nsegs,
1044 		    vtnet_tx_vq_intr, txq, &txq->vtntx_vq,
1045 		    "%s-tx%d", device_get_nameunit(dev), txq->vtntx_id);
1046 	}
1047 
1048 	/* These queues will not be used so allocate the minimum resources. */
1049 	for (/**/; i < sc->vtnet_max_vq_pairs; i++, idx += 2) {
1050 		rxq = &sc->vtnet_rxqs[i];
1051 		VQ_ALLOC_INFO_INIT(&info[idx], 0, NULL, rxq, &rxq->vtnrx_vq,
1052 		    "%s-rx%d", device_get_nameunit(dev), rxq->vtnrx_id);
1053 
1054 		txq = &sc->vtnet_txqs[i];
1055 		VQ_ALLOC_INFO_INIT(&info[idx+1], 0, NULL, txq, &txq->vtntx_vq,
1056 		    "%s-tx%d", device_get_nameunit(dev), txq->vtntx_id);
1057 	}
1058 
1059 	if (sc->vtnet_flags & VTNET_FLAG_CTRL_VQ) {
1060 		VQ_ALLOC_INFO_INIT(&info[idx], 0, NULL, NULL,
1061 		    &sc->vtnet_ctrl_vq, "%s ctrl", device_get_nameunit(dev));
1062 	}
1063 
1064 	/*
1065 	 * TODO: Enable interrupt binding if this is multiqueue. This will
1066 	 * only matter when per-virtqueue MSIX is available.
1067 	 */
1068 	if (sc->vtnet_flags & VTNET_FLAG_MQ)
1069 		flags |= 0;
1070 
1071 	error = virtio_alloc_virtqueues(dev, flags, nvqs, info);
1072 	free(info, M_TEMP);
1073 
1074 	return (error);
1075 }
1076 
1077 static int
1078 vtnet_alloc_interface(struct vtnet_softc *sc)
1079 {
1080 	device_t dev;
1081 	if_t ifp;
1082 
1083 	dev = sc->vtnet_dev;
1084 
1085 	ifp = if_alloc(IFT_ETHER);
1086 	if (ifp == NULL)
1087 		return (ENOMEM);
1088 
1089 	sc->vtnet_ifp = ifp;
1090 	if_setsoftc(ifp, sc);
1091 	if_initname(ifp, device_get_name(dev), device_get_unit(dev));
1092 
1093 	return (0);
1094 }
1095 
1096 static int
1097 vtnet_setup_interface(struct vtnet_softc *sc)
1098 {
1099 	device_t dev;
1100 	struct pfil_head_args pa;
1101 	if_t ifp;
1102 
1103 	dev = sc->vtnet_dev;
1104 	ifp = sc->vtnet_ifp;
1105 
1106 	if_setflags(ifp, IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST |
1107 	    IFF_KNOWSEPOCH);
1108 	if_setbaudrate(ifp, IF_Gbps(10));
1109 	if_setinitfn(ifp, vtnet_init);
1110 	if_setioctlfn(ifp, vtnet_ioctl);
1111 	if_setgetcounterfn(ifp, vtnet_get_counter);
1112 #ifndef VTNET_LEGACY_TX
1113 	if_settransmitfn(ifp, vtnet_txq_mq_start);
1114 	if_setqflushfn(ifp, vtnet_qflush);
1115 #else
1116 	struct virtqueue *vq = sc->vtnet_txqs[0].vtntx_vq;
1117 	if_setstartfn(ifp, vtnet_start);
1118 	if_setsendqlen(ifp, virtqueue_size(vq) - 1);
1119 	if_setsendqready(ifp);
1120 #endif
1121 
1122 	vtnet_get_macaddr(sc);
1123 
1124 	if (virtio_with_feature(dev, VIRTIO_NET_F_STATUS))
1125 		if_setcapabilitiesbit(ifp, IFCAP_LINKSTATE, 0);
1126 
1127 	ifmedia_init(&sc->vtnet_media, 0, vtnet_ifmedia_upd, vtnet_ifmedia_sts);
1128 	ifmedia_add(&sc->vtnet_media, IFM_ETHER | IFM_AUTO, 0, NULL);
1129 	ifmedia_set(&sc->vtnet_media, IFM_ETHER | IFM_AUTO);
1130 
1131 	if (virtio_with_feature(dev, VIRTIO_NET_F_CSUM)) {
1132 		int gso;
1133 
1134 		if_setcapabilitiesbit(ifp, IFCAP_TXCSUM | IFCAP_TXCSUM_IPV6, 0);
1135 
1136 		gso = virtio_with_feature(dev, VIRTIO_NET_F_GSO);
1137 		if (gso || virtio_with_feature(dev, VIRTIO_NET_F_HOST_TSO4))
1138 			if_setcapabilitiesbit(ifp, IFCAP_TSO4, 0);
1139 		if (gso || virtio_with_feature(dev, VIRTIO_NET_F_HOST_TSO6))
1140 			if_setcapabilitiesbit(ifp, IFCAP_TSO6, 0);
1141 		if (gso || virtio_with_feature(dev, VIRTIO_NET_F_HOST_ECN))
1142 			sc->vtnet_flags |= VTNET_FLAG_TSO_ECN;
1143 
1144 		if (if_getcapabilities(ifp) & (IFCAP_TSO4 | IFCAP_TSO6)) {
1145 			int tso_maxlen;
1146 
1147 			if_setcapabilitiesbit(ifp, IFCAP_VLAN_HWTSO, 0);
1148 
1149 			tso_maxlen = vtnet_tunable_int(sc, "tso_maxlen",
1150 			    vtnet_tso_maxlen);
1151 			if_sethwtsomax(ifp, tso_maxlen -
1152 			    (ETHER_HDR_LEN + ETHER_VLAN_ENCAP_LEN));
1153 			if_sethwtsomaxsegcount(ifp, sc->vtnet_tx_nsegs - 1);
1154 			if_sethwtsomaxsegsize(ifp, PAGE_SIZE);
1155 		}
1156 	}
1157 
1158 	if (virtio_with_feature(dev, VIRTIO_NET_F_GUEST_CSUM)) {
1159 		if_setcapabilitiesbit(ifp, IFCAP_RXCSUM, 0);
1160 #ifdef notyet
1161 		/* BMV: Rx checksums not distinguished between IPv4 and IPv6. */
1162 		if_setcapabilitiesbit(ifp, IFCAP_RXCSUM_IPV6, 0);
1163 #endif
1164 
1165 		if (vtnet_tunable_int(sc, "fixup_needs_csum",
1166 		    vtnet_fixup_needs_csum) != 0)
1167 			sc->vtnet_flags |= VTNET_FLAG_FIXUP_NEEDS_CSUM;
1168 
1169 		/* Support either "hardware" or software LRO. */
1170 		if_setcapabilitiesbit(ifp, IFCAP_LRO, 0);
1171 	}
1172 
1173 	if (if_getcapabilities(ifp) & (IFCAP_HWCSUM | IFCAP_HWCSUM_IPV6)) {
1174 		/*
1175 		 * VirtIO does not support VLAN tagging, but we can fake
1176 		 * it by inserting and removing the 802.1Q header during
1177 		 * transmit and receive. We are then able to do checksum
1178 		 * offloading of VLAN frames.
1179 		 */
1180 		if_setcapabilitiesbit(ifp, IFCAP_VLAN_HWTAGGING | IFCAP_VLAN_HWCSUM, 0);
1181 	}
1182 
1183 	if (sc->vtnet_max_mtu >= ETHERMTU_JUMBO)
1184 		if_setcapabilitiesbit(ifp, IFCAP_JUMBO_MTU, 0);
1185 	if_setcapabilitiesbit(ifp, IFCAP_VLAN_MTU, 0);
1186 
1187 	/*
1188 	 * Capabilities after here are not enabled by default.
1189 	 */
1190 	if_setcapenable(ifp, if_getcapabilities(ifp));
1191 
1192 	if (sc->vtnet_flags & VTNET_FLAG_VLAN_FILTER) {
1193 		if_setcapabilitiesbit(ifp, IFCAP_VLAN_HWFILTER, 0);
1194 
1195 		sc->vtnet_vlan_attach = EVENTHANDLER_REGISTER(vlan_config,
1196 		    vtnet_register_vlan, sc, EVENTHANDLER_PRI_FIRST);
1197 		sc->vtnet_vlan_detach = EVENTHANDLER_REGISTER(vlan_unconfig,
1198 		    vtnet_unregister_vlan, sc, EVENTHANDLER_PRI_FIRST);
1199 	}
1200 
1201 	ether_ifattach(ifp, sc->vtnet_hwaddr);
1202 
1203 	/* Tell the upper layer(s) we support long frames. */
1204 	if_setifheaderlen(ifp, sizeof(struct ether_vlan_header));
1205 
1206 	DEBUGNET_SET(ifp, vtnet);
1207 
1208 	pa.pa_version = PFIL_VERSION;
1209 	pa.pa_flags = PFIL_IN;
1210 	pa.pa_type = PFIL_TYPE_ETHERNET;
1211 	pa.pa_headname = if_name(ifp);
1212 	sc->vtnet_pfil = pfil_head_register(&pa);
1213 
1214 	return (0);
1215 }
1216 
1217 static int
1218 vtnet_rx_cluster_size(struct vtnet_softc *sc, int mtu)
1219 {
1220 	int framesz;
1221 
1222 	if (sc->vtnet_flags & VTNET_FLAG_MRG_RXBUFS)
1223 		return (MJUMPAGESIZE);
1224 	else if (sc->vtnet_flags & VTNET_FLAG_LRO_NOMRG)
1225 		return (MCLBYTES);
1226 
1227 	/*
1228 	 * Try to scale the receive mbuf cluster size from the MTU. We
1229 	 * could also use the VQ size to influence the selected size,
1230 	 * but that would only matter for very small queues.
1231 	 */
1232 	if (vtnet_modern(sc)) {
1233 		MPASS(sc->vtnet_hdr_size == sizeof(struct virtio_net_hdr_v1));
1234 		framesz = sizeof(struct virtio_net_hdr_v1);
1235 	} else
1236 		framesz = sizeof(struct vtnet_rx_header);
1237 	framesz += sizeof(struct ether_vlan_header) + mtu;
1238 
1239 	if (framesz <= MCLBYTES)
1240 		return (MCLBYTES);
1241 	else if (framesz <= MJUMPAGESIZE)
1242 		return (MJUMPAGESIZE);
1243 	else if (framesz <= MJUM9BYTES)
1244 		return (MJUM9BYTES);
1245 
1246 	/* Sane default; avoid 16KB clusters. */
1247 	return (MCLBYTES);
1248 }
1249 
1250 static int
1251 vtnet_ioctl_mtu(struct vtnet_softc *sc, u_int mtu)
1252 {
1253 	if_t ifp;
1254 	int clustersz;
1255 
1256 	ifp = sc->vtnet_ifp;
1257 	VTNET_CORE_LOCK_ASSERT(sc);
1258 
1259 	if (if_getmtu(ifp) == mtu)
1260 		return (0);
1261 	else if (mtu < ETHERMIN || mtu > sc->vtnet_max_mtu)
1262 		return (EINVAL);
1263 
1264 	if_setmtu(ifp, mtu);
1265 	clustersz = vtnet_rx_cluster_size(sc, mtu);
1266 
1267 	if (clustersz != sc->vtnet_rx_clustersz &&
1268 	    if_getdrvflags(ifp) & IFF_DRV_RUNNING) {
1269 		if_setdrvflagbits(ifp, 0, IFF_DRV_RUNNING);
1270 		vtnet_init_locked(sc, 0);
1271 	}
1272 
1273 	return (0);
1274 }
1275 
1276 static int
1277 vtnet_ioctl_ifflags(struct vtnet_softc *sc)
1278 {
1279 	if_t ifp;
1280 	int drv_running;
1281 
1282 	ifp = sc->vtnet_ifp;
1283 	drv_running = (if_getdrvflags(ifp) & IFF_DRV_RUNNING) != 0;
1284 
1285 	VTNET_CORE_LOCK_ASSERT(sc);
1286 
1287 	if ((if_getflags(ifp) & IFF_UP) == 0) {
1288 		if (drv_running)
1289 			vtnet_stop(sc);
1290 		goto out;
1291 	}
1292 
1293 	if (!drv_running) {
1294 		vtnet_init_locked(sc, 0);
1295 		goto out;
1296 	}
1297 
1298 	if ((if_getflags(ifp) ^ sc->vtnet_if_flags) &
1299 	    (IFF_PROMISC | IFF_ALLMULTI)) {
1300 		if (sc->vtnet_flags & VTNET_FLAG_CTRL_RX)
1301 			vtnet_rx_filter(sc);
1302 		else {
1303 			if ((if_getflags(ifp) ^ sc->vtnet_if_flags) & IFF_ALLMULTI)
1304 				return (ENOTSUP);
1305 			if_setflagbits(ifp, IFF_PROMISC, 0);
1306 		}
1307 	}
1308 
1309 out:
1310 	sc->vtnet_if_flags = if_getflags(ifp);
1311 	return (0);
1312 }
1313 
1314 static int
1315 vtnet_ioctl_multi(struct vtnet_softc *sc)
1316 {
1317 	if_t ifp;
1318 
1319 	ifp = sc->vtnet_ifp;
1320 
1321 	VTNET_CORE_LOCK_ASSERT(sc);
1322 
1323 	if (sc->vtnet_flags & VTNET_FLAG_CTRL_RX &&
1324 	    if_getdrvflags(ifp) & IFF_DRV_RUNNING)
1325 		vtnet_rx_filter_mac(sc);
1326 
1327 	return (0);
1328 }
1329 
1330 static int
1331 vtnet_ioctl_ifcap(struct vtnet_softc *sc, struct ifreq *ifr)
1332 {
1333 	if_t ifp;
1334 	int mask, reinit, update;
1335 
1336 	ifp = sc->vtnet_ifp;
1337 	mask = (ifr->ifr_reqcap & if_getcapabilities(ifp)) ^ if_getcapenable(ifp);
1338 	reinit = update = 0;
1339 
1340 	VTNET_CORE_LOCK_ASSERT(sc);
1341 
1342 	if (mask & IFCAP_TXCSUM)
1343 		if_togglecapenable(ifp, IFCAP_TXCSUM);
1344 	if (mask & IFCAP_TXCSUM_IPV6)
1345 		if_togglecapenable(ifp, IFCAP_TXCSUM_IPV6);
1346 	if (mask & IFCAP_TSO4)
1347 		if_togglecapenable(ifp, IFCAP_TSO4);
1348 	if (mask & IFCAP_TSO6)
1349 		if_togglecapenable(ifp, IFCAP_TSO6);
1350 
1351 	if (mask & (IFCAP_RXCSUM | IFCAP_RXCSUM_IPV6 | IFCAP_LRO)) {
1352 		/*
1353 		 * These Rx features require the negotiated features to
1354 		 * be updated. Avoid a full reinit if possible.
1355 		 */
1356 		if (sc->vtnet_features & VIRTIO_NET_F_CTRL_GUEST_OFFLOADS)
1357 			update = 1;
1358 		else
1359 			reinit = 1;
1360 
1361 		/* BMV: Avoid needless renegotiation for just software LRO. */
1362 		if ((mask & (IFCAP_RXCSUM | IFCAP_RXCSUM_IPV6 | IFCAP_LRO)) ==
1363 		    IFCAP_LRO && vtnet_software_lro(sc))
1364 			reinit = update = 0;
1365 
1366 		if (mask & IFCAP_RXCSUM)
1367 			if_togglecapenable(ifp, IFCAP_RXCSUM);
1368 		if (mask & IFCAP_RXCSUM_IPV6)
1369 			if_togglecapenable(ifp, IFCAP_RXCSUM_IPV6);
1370 		if (mask & IFCAP_LRO)
1371 			if_togglecapenable(ifp, IFCAP_LRO);
1372 
1373 		/*
1374 		 * VirtIO does not distinguish between IPv4 and IPv6 checksums
1375 		 * so treat them as a pair. Guest TSO (LRO) requires receive
1376 		 * checksums.
1377 		 */
1378 		if (if_getcapenable(ifp) & (IFCAP_RXCSUM | IFCAP_RXCSUM_IPV6)) {
1379 			if_setcapenablebit(ifp, IFCAP_RXCSUM, 0);
1380 #ifdef notyet
1381 			if_setcapenablebit(ifp, IFCAP_RXCSUM_IPV6, 0);
1382 #endif
1383 		} else
1384 			if_setcapenablebit(ifp, 0,
1385 			    (IFCAP_RXCSUM | IFCAP_RXCSUM_IPV6 | IFCAP_LRO));
1386 	}
1387 
1388 	if (mask & IFCAP_VLAN_HWFILTER) {
1389 		/* These Rx features require renegotiation. */
1390 		reinit = 1;
1391 
1392 		if (mask & IFCAP_VLAN_HWFILTER)
1393 			if_togglecapenable(ifp, IFCAP_VLAN_HWFILTER);
1394 	}
1395 
1396 	if (mask & IFCAP_VLAN_HWTSO)
1397 		if_togglecapenable(ifp, IFCAP_VLAN_HWTSO);
1398 	if (mask & IFCAP_VLAN_HWTAGGING)
1399 		if_togglecapenable(ifp, IFCAP_VLAN_HWTAGGING);
1400 
1401 	if (if_getdrvflags(ifp) & IFF_DRV_RUNNING) {
1402 		if (reinit) {
1403 			if_setdrvflagbits(ifp, 0, IFF_DRV_RUNNING);
1404 			vtnet_init_locked(sc, 0);
1405 		} else if (update)
1406 			vtnet_update_rx_offloads(sc);
1407 	}
1408 
1409 	return (0);
1410 }
1411 
1412 static int
1413 vtnet_ioctl(if_t ifp, u_long cmd, caddr_t data)
1414 {
1415 	struct vtnet_softc *sc;
1416 	struct ifreq *ifr;
1417 	int error;
1418 
1419 	sc = if_getsoftc(ifp);
1420 	ifr = (struct ifreq *) data;
1421 	error = 0;
1422 
1423 	switch (cmd) {
1424 	case SIOCSIFMTU:
1425 		VTNET_CORE_LOCK(sc);
1426 		error = vtnet_ioctl_mtu(sc, ifr->ifr_mtu);
1427 		VTNET_CORE_UNLOCK(sc);
1428 		break;
1429 
1430 	case SIOCSIFFLAGS:
1431 		VTNET_CORE_LOCK(sc);
1432 		error = vtnet_ioctl_ifflags(sc);
1433 		VTNET_CORE_UNLOCK(sc);
1434 		break;
1435 
1436 	case SIOCADDMULTI:
1437 	case SIOCDELMULTI:
1438 		VTNET_CORE_LOCK(sc);
1439 		error = vtnet_ioctl_multi(sc);
1440 		VTNET_CORE_UNLOCK(sc);
1441 		break;
1442 
1443 	case SIOCSIFMEDIA:
1444 	case SIOCGIFMEDIA:
1445 		error = ifmedia_ioctl(ifp, ifr, &sc->vtnet_media, cmd);
1446 		break;
1447 
1448 	case SIOCSIFCAP:
1449 		VTNET_CORE_LOCK(sc);
1450 		error = vtnet_ioctl_ifcap(sc, ifr);
1451 		VTNET_CORE_UNLOCK(sc);
1452 		VLAN_CAPABILITIES(ifp);
1453 		break;
1454 
1455 	default:
1456 		error = ether_ioctl(ifp, cmd, data);
1457 		break;
1458 	}
1459 
1460 	VTNET_CORE_LOCK_ASSERT_NOTOWNED(sc);
1461 
1462 	return (error);
1463 }
1464 
1465 static int
1466 vtnet_rxq_populate(struct vtnet_rxq *rxq)
1467 {
1468 	struct virtqueue *vq;
1469 	int nbufs, error;
1470 
1471 #ifdef DEV_NETMAP
1472 	error = vtnet_netmap_rxq_populate(rxq);
1473 	if (error >= 0)
1474 		return (error);
1475 #endif  /* DEV_NETMAP */
1476 
1477 	vq = rxq->vtnrx_vq;
1478 	error = ENOSPC;
1479 
1480 	for (nbufs = 0; !virtqueue_full(vq); nbufs++) {
1481 		error = vtnet_rxq_new_buf(rxq);
1482 		if (error)
1483 			break;
1484 	}
1485 
1486 	if (nbufs > 0) {
1487 		virtqueue_notify(vq);
1488 		/*
1489 		 * EMSGSIZE signifies the virtqueue did not have enough
1490 		 * entries available to hold the last mbuf. This is not
1491 		 * an error.
1492 		 */
1493 		if (error == EMSGSIZE)
1494 			error = 0;
1495 	}
1496 
1497 	return (error);
1498 }
1499 
1500 static void
1501 vtnet_rxq_free_mbufs(struct vtnet_rxq *rxq)
1502 {
1503 	struct virtqueue *vq;
1504 	struct mbuf *m;
1505 	int last;
1506 #ifdef DEV_NETMAP
1507 	struct netmap_kring *kring = netmap_kring_on(NA(rxq->vtnrx_sc->vtnet_ifp),
1508 							rxq->vtnrx_id, NR_RX);
1509 #else  /* !DEV_NETMAP */
1510 	void *kring = NULL;
1511 #endif /* !DEV_NETMAP */
1512 
1513 	vq = rxq->vtnrx_vq;
1514 	last = 0;
1515 
1516 	while ((m = virtqueue_drain(vq, &last)) != NULL) {
1517 		if (kring == NULL)
1518 			m_freem(m);
1519 	}
1520 
1521 	KASSERT(virtqueue_empty(vq),
1522 	    ("%s: mbufs remaining in rx queue %p", __func__, rxq));
1523 }
1524 
1525 static struct mbuf *
1526 vtnet_rx_alloc_buf(struct vtnet_softc *sc, int nbufs, struct mbuf **m_tailp)
1527 {
1528 	struct mbuf *m_head, *m_tail, *m;
1529 	int i, size;
1530 
1531 	m_head = NULL;
1532 	size = sc->vtnet_rx_clustersz;
1533 
1534 	KASSERT(nbufs == 1 || sc->vtnet_flags & VTNET_FLAG_LRO_NOMRG,
1535 	    ("%s: mbuf %d chain requested without LRO_NOMRG", __func__, nbufs));
1536 
1537 	for (i = 0; i < nbufs; i++) {
1538 		m = m_getjcl(M_NOWAIT, MT_DATA, i == 0 ? M_PKTHDR : 0, size);
1539 		if (m == NULL) {
1540 			sc->vtnet_stats.mbuf_alloc_failed++;
1541 			m_freem(m_head);
1542 			return (NULL);
1543 		}
1544 
1545 		m->m_len = size;
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 
1573 	m_prev = NULL;
1574 	m_tail = NULL;
1575 	nreplace = 0;
1576 
1577 	m = m0;
1578 	len = len0;
1579 
1580 	/*
1581 	 * Since these mbuf chains are so large, avoid allocating a complete
1582 	 * replacement when the received frame did not consume the entire
1583 	 * chain. Unused mbufs are moved to the tail of the replacement mbuf.
1584 	 */
1585 	while (len > 0) {
1586 		if (m == NULL) {
1587 			sc->vtnet_stats.rx_frame_too_large++;
1588 			return (EMSGSIZE);
1589 		}
1590 
1591 		/*
1592 		 * Every mbuf should have the expected cluster size since that
1593 		 * is also used to allocate the replacements.
1594 		 */
1595 		KASSERT(m->m_len == clustersz,
1596 		    ("%s: mbuf size %d not expected cluster size %d", __func__,
1597 		    m->m_len, clustersz));
1598 
1599 		m->m_len = MIN(m->m_len, len);
1600 		len -= m->m_len;
1601 
1602 		m_prev = m;
1603 		m = m->m_next;
1604 		nreplace++;
1605 	}
1606 
1607 	KASSERT(nreplace > 0 && nreplace <= sc->vtnet_rx_nmbufs,
1608 	    ("%s: invalid replacement mbuf count %d max %d", __func__,
1609 	    nreplace, sc->vtnet_rx_nmbufs));
1610 
1611 	m_new = vtnet_rx_alloc_buf(sc, nreplace, &m_tail);
1612 	if (m_new == NULL) {
1613 		m_prev->m_len = clustersz;
1614 		return (ENOBUFS);
1615 	}
1616 
1617 	/*
1618 	 * Move any unused mbufs from the received mbuf chain onto the
1619 	 * end of the replacement chain.
1620 	 */
1621 	if (m_prev->m_next != NULL) {
1622 		m_tail->m_next = m_prev->m_next;
1623 		m_prev->m_next = NULL;
1624 	}
1625 
1626 	error = vtnet_rxq_enqueue_buf(rxq, m_new);
1627 	if (error) {
1628 		/*
1629 		 * The replacement is suppose to be an copy of the one
1630 		 * dequeued so this is a very unexpected error.
1631 		 *
1632 		 * Restore the m0 chain to the original state if it was
1633 		 * modified so we can then discard it.
1634 		 */
1635 		if (m_tail->m_next != NULL) {
1636 			m_prev->m_next = m_tail->m_next;
1637 			m_tail->m_next = NULL;
1638 		}
1639 		m_prev->m_len = clustersz;
1640 		sc->vtnet_stats.rx_enq_replacement_failed++;
1641 		m_freem(m_new);
1642 	}
1643 
1644 	return (error);
1645 }
1646 
1647 static int
1648 vtnet_rxq_replace_buf(struct vtnet_rxq *rxq, struct mbuf *m, int len)
1649 {
1650 	struct vtnet_softc *sc;
1651 	struct mbuf *m_new;
1652 	int error;
1653 
1654 	sc = rxq->vtnrx_sc;
1655 
1656 	if (sc->vtnet_flags & VTNET_FLAG_LRO_NOMRG)
1657 		return (vtnet_rxq_replace_lro_nomrg_buf(rxq, m, len));
1658 
1659 	MPASS(m->m_next == NULL);
1660 	if (m->m_len < len)
1661 		return (EMSGSIZE);
1662 
1663 	m_new = vtnet_rx_alloc_buf(sc, 1, NULL);
1664 	if (m_new == NULL)
1665 		return (ENOBUFS);
1666 
1667 	error = vtnet_rxq_enqueue_buf(rxq, m_new);
1668 	if (error) {
1669 		sc->vtnet_stats.rx_enq_replacement_failed++;
1670 		m_freem(m_new);
1671 	} else
1672 		m->m_len = len;
1673 
1674 	return (error);
1675 }
1676 
1677 static int
1678 vtnet_rxq_enqueue_buf(struct vtnet_rxq *rxq, struct mbuf *m)
1679 {
1680 	struct vtnet_softc *sc;
1681 	struct sglist *sg;
1682 	int header_inlined, error;
1683 
1684 	sc = rxq->vtnrx_sc;
1685 	sg = rxq->vtnrx_sg;
1686 
1687 	KASSERT(m->m_next == NULL || sc->vtnet_flags & VTNET_FLAG_LRO_NOMRG,
1688 	    ("%s: mbuf chain without LRO_NOMRG", __func__));
1689 	VTNET_RXQ_LOCK_ASSERT(rxq);
1690 
1691 	sglist_reset(sg);
1692 	header_inlined = vtnet_modern(sc) ||
1693 	    (sc->vtnet_flags & VTNET_FLAG_MRG_RXBUFS) != 0; /* TODO: ANY_LAYOUT */
1694 
1695 	if (header_inlined)
1696 		error = sglist_append_mbuf(sg, m);
1697 	else {
1698 		struct vtnet_rx_header *rxhdr =
1699 		    mtod(m, struct vtnet_rx_header *);
1700 		MPASS(sc->vtnet_hdr_size == sizeof(struct virtio_net_hdr));
1701 
1702 		/* Append the header and remaining mbuf data. */
1703 		error = sglist_append(sg, &rxhdr->vrh_hdr, sc->vtnet_hdr_size);
1704 		if (error)
1705 			return (error);
1706 		error = sglist_append(sg, &rxhdr[1],
1707 		    m->m_len - sizeof(struct vtnet_rx_header));
1708 		if (error)
1709 			return (error);
1710 
1711 		if (m->m_next != NULL)
1712 			error = sglist_append_mbuf(sg, m->m_next);
1713 	}
1714 
1715 	if (error)
1716 		return (error);
1717 
1718 	return (virtqueue_enqueue(rxq->vtnrx_vq, m, sg, 0, sg->sg_nseg));
1719 }
1720 
1721 static int
1722 vtnet_rxq_new_buf(struct vtnet_rxq *rxq)
1723 {
1724 	struct vtnet_softc *sc;
1725 	struct mbuf *m;
1726 	int error;
1727 
1728 	sc = rxq->vtnrx_sc;
1729 
1730 	m = vtnet_rx_alloc_buf(sc, sc->vtnet_rx_nmbufs, NULL);
1731 	if (m == NULL)
1732 		return (ENOBUFS);
1733 
1734 	error = vtnet_rxq_enqueue_buf(rxq, m);
1735 	if (error)
1736 		m_freem(m);
1737 
1738 	return (error);
1739 }
1740 
1741 static int
1742 vtnet_rxq_csum_needs_csum(struct vtnet_rxq *rxq, struct mbuf *m, uint16_t etype,
1743     int hoff, struct virtio_net_hdr *hdr)
1744 {
1745 	struct vtnet_softc *sc;
1746 	int error;
1747 
1748 	sc = rxq->vtnrx_sc;
1749 
1750 	/*
1751 	 * NEEDS_CSUM corresponds to Linux's CHECKSUM_PARTIAL, but FreeBSD does
1752 	 * not have an analogous CSUM flag. The checksum has been validated,
1753 	 * but is incomplete (TCP/UDP pseudo header).
1754 	 *
1755 	 * The packet is likely from another VM on the same host that itself
1756 	 * performed checksum offloading so Tx/Rx is basically a memcpy and
1757 	 * the checksum has little value.
1758 	 *
1759 	 * Default to receiving the packet as-is for performance reasons, but
1760 	 * this can cause issues if the packet is to be forwarded because it
1761 	 * does not contain a valid checksum. This patch may be helpful:
1762 	 * https://reviews.freebsd.org/D6611. In the meantime, have the driver
1763 	 * compute the checksum if requested.
1764 	 *
1765 	 * BMV: Need to add an CSUM_PARTIAL flag?
1766 	 */
1767 	if ((sc->vtnet_flags & VTNET_FLAG_FIXUP_NEEDS_CSUM) == 0) {
1768 		error = vtnet_rxq_csum_data_valid(rxq, m, etype, hoff, hdr);
1769 		return (error);
1770 	}
1771 
1772 	/*
1773 	 * Compute the checksum in the driver so the packet will contain a
1774 	 * valid checksum. The checksum is at csum_offset from csum_start.
1775 	 */
1776 	switch (etype) {
1777 #if defined(INET) || defined(INET6)
1778 	case ETHERTYPE_IP:
1779 	case ETHERTYPE_IPV6: {
1780 		int csum_off, csum_end;
1781 		uint16_t csum;
1782 
1783 		csum_off = hdr->csum_start + hdr->csum_offset;
1784 		csum_end = csum_off + sizeof(uint16_t);
1785 
1786 		/* Assume checksum will be in the first mbuf. */
1787 		if (m->m_len < csum_end || m->m_pkthdr.len < csum_end)
1788 			return (1);
1789 
1790 		/*
1791 		 * Like in_delayed_cksum()/in6_delayed_cksum(), compute the
1792 		 * checksum and write it at the specified offset. We could
1793 		 * try to verify the packet: csum_start should probably
1794 		 * correspond to the start of the TCP/UDP header.
1795 		 *
1796 		 * BMV: Need to properly handle UDP with zero checksum. Is
1797 		 * the IPv4 header checksum implicitly validated?
1798 		 */
1799 		csum = in_cksum_skip(m, m->m_pkthdr.len, hdr->csum_start);
1800 		*(uint16_t *)(mtodo(m, csum_off)) = csum;
1801 		m->m_pkthdr.csum_flags |= CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
1802 		m->m_pkthdr.csum_data = 0xFFFF;
1803 		break;
1804 	}
1805 #endif
1806 	default:
1807 		sc->vtnet_stats.rx_csum_bad_ethtype++;
1808 		return (1);
1809 	}
1810 
1811 	return (0);
1812 }
1813 
1814 static int
1815 vtnet_rxq_csum_data_valid(struct vtnet_rxq *rxq, struct mbuf *m,
1816     uint16_t etype, int hoff, struct virtio_net_hdr *hdr __unused)
1817 {
1818 #if 0
1819 	struct vtnet_softc *sc;
1820 #endif
1821 	int protocol;
1822 
1823 #if 0
1824 	sc = rxq->vtnrx_sc;
1825 #endif
1826 
1827 	switch (etype) {
1828 #if defined(INET)
1829 	case ETHERTYPE_IP:
1830 		if (__predict_false(m->m_len < hoff + sizeof(struct ip)))
1831 			protocol = IPPROTO_DONE;
1832 		else {
1833 			struct ip *ip = (struct ip *)(m->m_data + hoff);
1834 			protocol = ip->ip_p;
1835 		}
1836 		break;
1837 #endif
1838 #if defined(INET6)
1839 	case ETHERTYPE_IPV6:
1840 		if (__predict_false(m->m_len < hoff + sizeof(struct ip6_hdr))
1841 		    || ip6_lasthdr(m, hoff, IPPROTO_IPV6, &protocol) < 0)
1842 			protocol = IPPROTO_DONE;
1843 		break;
1844 #endif
1845 	default:
1846 		protocol = IPPROTO_DONE;
1847 		break;
1848 	}
1849 
1850 	switch (protocol) {
1851 	case IPPROTO_TCP:
1852 	case IPPROTO_UDP:
1853 		m->m_pkthdr.csum_flags |= CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
1854 		m->m_pkthdr.csum_data = 0xFFFF;
1855 		break;
1856 	default:
1857 		/*
1858 		 * FreeBSD does not support checksum offloading of this
1859 		 * protocol. Let the stack re-verify the checksum later
1860 		 * if the protocol is supported.
1861 		 */
1862 #if 0
1863 		if_printf(sc->vtnet_ifp,
1864 		    "%s: checksum offload of unsupported protocol "
1865 		    "etype=%#x protocol=%d csum_start=%d csum_offset=%d\n",
1866 		    __func__, etype, protocol, hdr->csum_start,
1867 		    hdr->csum_offset);
1868 #endif
1869 		break;
1870 	}
1871 
1872 	return (0);
1873 }
1874 
1875 static int
1876 vtnet_rxq_csum(struct vtnet_rxq *rxq, struct mbuf *m,
1877     struct virtio_net_hdr *hdr)
1878 {
1879 	const struct ether_header *eh;
1880 	int hoff;
1881 	uint16_t etype;
1882 
1883 	eh = mtod(m, const struct ether_header *);
1884 	etype = ntohs(eh->ether_type);
1885 	if (etype == ETHERTYPE_VLAN) {
1886 		/* TODO BMV: Handle QinQ. */
1887 		const struct ether_vlan_header *evh =
1888 		    mtod(m, const struct ether_vlan_header *);
1889 		etype = ntohs(evh->evl_proto);
1890 		hoff = sizeof(struct ether_vlan_header);
1891 	} else
1892 		hoff = sizeof(struct ether_header);
1893 
1894 	if (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM)
1895 		return (vtnet_rxq_csum_needs_csum(rxq, m, etype, hoff, hdr));
1896 	else /* VIRTIO_NET_HDR_F_DATA_VALID */
1897 		return (vtnet_rxq_csum_data_valid(rxq, m, etype, hoff, hdr));
1898 }
1899 
1900 static void
1901 vtnet_rxq_discard_merged_bufs(struct vtnet_rxq *rxq, int nbufs)
1902 {
1903 	struct mbuf *m;
1904 
1905 	while (--nbufs > 0) {
1906 		m = virtqueue_dequeue(rxq->vtnrx_vq, NULL);
1907 		if (m == NULL)
1908 			break;
1909 		vtnet_rxq_discard_buf(rxq, m);
1910 	}
1911 }
1912 
1913 static void
1914 vtnet_rxq_discard_buf(struct vtnet_rxq *rxq, struct mbuf *m)
1915 {
1916 	int error __diagused;
1917 
1918 	/*
1919 	 * Requeue the discarded mbuf. This should always be successful
1920 	 * since it was just dequeued.
1921 	 */
1922 	error = vtnet_rxq_enqueue_buf(rxq, m);
1923 	KASSERT(error == 0,
1924 	    ("%s: cannot requeue discarded mbuf %d", __func__, error));
1925 }
1926 
1927 static int
1928 vtnet_rxq_merged_eof(struct vtnet_rxq *rxq, struct mbuf *m_head, int nbufs)
1929 {
1930 	struct vtnet_softc *sc;
1931 	struct virtqueue *vq;
1932 	struct mbuf *m_tail;
1933 
1934 	sc = rxq->vtnrx_sc;
1935 	vq = rxq->vtnrx_vq;
1936 	m_tail = m_head;
1937 
1938 	while (--nbufs > 0) {
1939 		struct mbuf *m;
1940 		uint32_t len;
1941 
1942 		m = virtqueue_dequeue(vq, &len);
1943 		if (m == NULL) {
1944 			rxq->vtnrx_stats.vrxs_ierrors++;
1945 			goto fail;
1946 		}
1947 
1948 		if (vtnet_rxq_new_buf(rxq) != 0) {
1949 			rxq->vtnrx_stats.vrxs_iqdrops++;
1950 			vtnet_rxq_discard_buf(rxq, m);
1951 			if (nbufs > 1)
1952 				vtnet_rxq_discard_merged_bufs(rxq, nbufs);
1953 			goto fail;
1954 		}
1955 
1956 		if (m->m_len < len)
1957 			len = m->m_len;
1958 
1959 		m->m_len = len;
1960 		m->m_flags &= ~M_PKTHDR;
1961 
1962 		m_head->m_pkthdr.len += len;
1963 		m_tail->m_next = m;
1964 		m_tail = m;
1965 	}
1966 
1967 	return (0);
1968 
1969 fail:
1970 	sc->vtnet_stats.rx_mergeable_failed++;
1971 	m_freem(m_head);
1972 
1973 	return (1);
1974 }
1975 
1976 #if defined(INET) || defined(INET6)
1977 static int
1978 vtnet_lro_rx(struct vtnet_rxq *rxq, struct mbuf *m)
1979 {
1980 	struct lro_ctrl *lro;
1981 
1982 	lro = &rxq->vtnrx_lro;
1983 
1984 	if (lro->lro_mbuf_max != 0) {
1985 		tcp_lro_queue_mbuf(lro, m);
1986 		return (0);
1987 	}
1988 
1989 	return (tcp_lro_rx(lro, m, 0));
1990 }
1991 #endif
1992 
1993 static void
1994 vtnet_rxq_input(struct vtnet_rxq *rxq, struct mbuf *m,
1995     struct virtio_net_hdr *hdr)
1996 {
1997 	struct vtnet_softc *sc;
1998 	if_t ifp;
1999 
2000 	sc = rxq->vtnrx_sc;
2001 	ifp = sc->vtnet_ifp;
2002 
2003 	if (if_getcapenable(ifp) & IFCAP_VLAN_HWTAGGING) {
2004 		struct ether_header *eh = mtod(m, struct ether_header *);
2005 		if (eh->ether_type == htons(ETHERTYPE_VLAN)) {
2006 			vtnet_vlan_tag_remove(m);
2007 			/*
2008 			 * With the 802.1Q header removed, update the
2009 			 * checksum starting location accordingly.
2010 			 */
2011 			if (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM)
2012 				hdr->csum_start -= ETHER_VLAN_ENCAP_LEN;
2013 		}
2014 	}
2015 
2016 	m->m_pkthdr.flowid = rxq->vtnrx_id;
2017 	M_HASHTYPE_SET(m, M_HASHTYPE_OPAQUE);
2018 
2019 	if (hdr->flags &
2020 	    (VIRTIO_NET_HDR_F_NEEDS_CSUM | VIRTIO_NET_HDR_F_DATA_VALID)) {
2021 		if (vtnet_rxq_csum(rxq, m, hdr) == 0)
2022 			rxq->vtnrx_stats.vrxs_csum++;
2023 		else
2024 			rxq->vtnrx_stats.vrxs_csum_failed++;
2025 	}
2026 
2027 	if (hdr->gso_size != 0) {
2028 		switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
2029 		case VIRTIO_NET_HDR_GSO_TCPV4:
2030 		case VIRTIO_NET_HDR_GSO_TCPV6:
2031 			m->m_pkthdr.lro_nsegs =
2032 			    howmany(m->m_pkthdr.len, hdr->gso_size);
2033 			rxq->vtnrx_stats.vrxs_host_lro++;
2034 			break;
2035 		}
2036 	}
2037 
2038 	rxq->vtnrx_stats.vrxs_ipackets++;
2039 	rxq->vtnrx_stats.vrxs_ibytes += m->m_pkthdr.len;
2040 
2041 #if defined(INET) || defined(INET6)
2042 	if (vtnet_software_lro(sc) && if_getcapenable(ifp) & IFCAP_LRO) {
2043 		if (vtnet_lro_rx(rxq, m) == 0)
2044 			return;
2045 	}
2046 #endif
2047 
2048 	if_input(ifp, m);
2049 }
2050 
2051 static int
2052 vtnet_rxq_eof(struct vtnet_rxq *rxq)
2053 {
2054 	struct virtio_net_hdr lhdr, *hdr;
2055 	struct vtnet_softc *sc;
2056 	if_t ifp;
2057 	struct virtqueue *vq;
2058 	int deq, count;
2059 
2060 	sc = rxq->vtnrx_sc;
2061 	vq = rxq->vtnrx_vq;
2062 	ifp = sc->vtnet_ifp;
2063 	deq = 0;
2064 	count = sc->vtnet_rx_process_limit;
2065 
2066 	VTNET_RXQ_LOCK_ASSERT(rxq);
2067 
2068 	while (count-- > 0) {
2069 		struct mbuf *m;
2070 		uint32_t len, nbufs, adjsz;
2071 
2072 		m = virtqueue_dequeue(vq, &len);
2073 		if (m == NULL)
2074 			break;
2075 		deq++;
2076 
2077 		if (len < sc->vtnet_hdr_size + ETHER_HDR_LEN) {
2078 			rxq->vtnrx_stats.vrxs_ierrors++;
2079 			vtnet_rxq_discard_buf(rxq, m);
2080 			continue;
2081 		}
2082 
2083 		if (sc->vtnet_flags & VTNET_FLAG_MRG_RXBUFS) {
2084 			struct virtio_net_hdr_mrg_rxbuf *mhdr =
2085 			    mtod(m, struct virtio_net_hdr_mrg_rxbuf *);
2086 			kmsan_mark(mhdr, sizeof(*mhdr), KMSAN_STATE_INITED);
2087 			nbufs = vtnet_htog16(sc, mhdr->num_buffers);
2088 			adjsz = sizeof(struct virtio_net_hdr_mrg_rxbuf);
2089 		} else if (vtnet_modern(sc)) {
2090 			nbufs = 1; /* num_buffers is always 1 */
2091 			adjsz = sizeof(struct virtio_net_hdr_v1);
2092 		} else {
2093 			nbufs = 1;
2094 			adjsz = sizeof(struct vtnet_rx_header);
2095 			/*
2096 			 * Account for our gap between the header and start of
2097 			 * data to keep the segments separated.
2098 			 */
2099 			len += VTNET_RX_HEADER_PAD;
2100 		}
2101 
2102 		if (vtnet_rxq_replace_buf(rxq, m, len) != 0) {
2103 			rxq->vtnrx_stats.vrxs_iqdrops++;
2104 			vtnet_rxq_discard_buf(rxq, m);
2105 			if (nbufs > 1)
2106 				vtnet_rxq_discard_merged_bufs(rxq, nbufs);
2107 			continue;
2108 		}
2109 
2110 		m->m_pkthdr.len = len;
2111 		m->m_pkthdr.rcvif = ifp;
2112 		m->m_pkthdr.csum_flags = 0;
2113 
2114 		if (nbufs > 1) {
2115 			/* Dequeue the rest of chain. */
2116 			if (vtnet_rxq_merged_eof(rxq, m, nbufs) != 0)
2117 				continue;
2118 		}
2119 
2120 		kmsan_mark_mbuf(m, KMSAN_STATE_INITED);
2121 
2122 		/*
2123 		 * Save an endian swapped version of the header prior to it
2124 		 * being stripped. The header is always at the start of the
2125 		 * mbuf data. num_buffers was already saved (and not needed)
2126 		 * so use the standard header.
2127 		 */
2128 		hdr = mtod(m, struct virtio_net_hdr *);
2129 		lhdr.flags = hdr->flags;
2130 		lhdr.gso_type = hdr->gso_type;
2131 		lhdr.hdr_len = vtnet_htog16(sc, hdr->hdr_len);
2132 		lhdr.gso_size = vtnet_htog16(sc, hdr->gso_size);
2133 		lhdr.csum_start = vtnet_htog16(sc, hdr->csum_start);
2134 		lhdr.csum_offset = vtnet_htog16(sc, hdr->csum_offset);
2135 		m_adj(m, adjsz);
2136 
2137 		if (PFIL_HOOKED_IN(sc->vtnet_pfil)) {
2138 			pfil_return_t pfil;
2139 
2140 			pfil = pfil_run_hooks(sc->vtnet_pfil, &m, ifp, PFIL_IN,
2141 			    NULL);
2142 			switch (pfil) {
2143 			case PFIL_REALLOCED:
2144 				m = pfil_mem2mbuf(m->m_data);
2145 				break;
2146 			case PFIL_DROPPED:
2147 			case PFIL_CONSUMED:
2148 				continue;
2149 			default:
2150 				KASSERT(pfil == PFIL_PASS,
2151 				    ("Filter returned %d!", pfil));
2152 			}
2153 		}
2154 
2155 		vtnet_rxq_input(rxq, m, &lhdr);
2156 	}
2157 
2158 	if (deq > 0) {
2159 #if defined(INET) || defined(INET6)
2160 		if (vtnet_software_lro(sc))
2161 			tcp_lro_flush_all(&rxq->vtnrx_lro);
2162 #endif
2163 		virtqueue_notify(vq);
2164 	}
2165 
2166 	return (count > 0 ? 0 : EAGAIN);
2167 }
2168 
2169 static void
2170 vtnet_rx_vq_process(struct vtnet_rxq *rxq, int tries)
2171 {
2172 	struct vtnet_softc *sc;
2173 	if_t ifp;
2174 	u_int more;
2175 #ifdef DEV_NETMAP
2176 	int nmirq;
2177 #endif /* DEV_NETMAP */
2178 
2179 	sc = rxq->vtnrx_sc;
2180 	ifp = sc->vtnet_ifp;
2181 
2182 	if (__predict_false(rxq->vtnrx_id >= sc->vtnet_act_vq_pairs)) {
2183 		/*
2184 		 * Ignore this interrupt. Either this is a spurious interrupt
2185 		 * or multiqueue without per-VQ MSIX so every queue needs to
2186 		 * be polled (a brain dead configuration we could try harder
2187 		 * to avoid).
2188 		 */
2189 		vtnet_rxq_disable_intr(rxq);
2190 		return;
2191 	}
2192 
2193 	VTNET_RXQ_LOCK(rxq);
2194 
2195 #ifdef DEV_NETMAP
2196 	/*
2197 	 * We call netmap_rx_irq() under lock to prevent concurrent calls.
2198 	 * This is not necessary to serialize the access to the RX vq, but
2199 	 * rather to avoid races that may happen if this interface is
2200 	 * attached to a VALE switch, which would cause received packets
2201 	 * to stall in the RX queue (nm_kr_tryget() could find the kring
2202 	 * busy when called from netmap_bwrap_intr_notify()).
2203 	 */
2204 	nmirq = netmap_rx_irq(ifp, rxq->vtnrx_id, &more);
2205 	if (nmirq != NM_IRQ_PASS) {
2206 		VTNET_RXQ_UNLOCK(rxq);
2207 		if (nmirq == NM_IRQ_RESCHED) {
2208 			taskqueue_enqueue(rxq->vtnrx_tq, &rxq->vtnrx_intrtask);
2209 		}
2210 		return;
2211 	}
2212 #endif /* DEV_NETMAP */
2213 
2214 again:
2215 	if ((if_getdrvflags(ifp) & IFF_DRV_RUNNING) == 0) {
2216 		VTNET_RXQ_UNLOCK(rxq);
2217 		return;
2218 	}
2219 
2220 	more = vtnet_rxq_eof(rxq);
2221 	if (more || vtnet_rxq_enable_intr(rxq) != 0) {
2222 		if (!more)
2223 			vtnet_rxq_disable_intr(rxq);
2224 		/*
2225 		 * This is an occasional condition or race (when !more),
2226 		 * so retry a few times before scheduling the taskqueue.
2227 		 */
2228 		if (tries-- > 0)
2229 			goto again;
2230 
2231 		rxq->vtnrx_stats.vrxs_rescheduled++;
2232 		VTNET_RXQ_UNLOCK(rxq);
2233 		taskqueue_enqueue(rxq->vtnrx_tq, &rxq->vtnrx_intrtask);
2234 	} else
2235 		VTNET_RXQ_UNLOCK(rxq);
2236 }
2237 
2238 static void
2239 vtnet_rx_vq_intr(void *xrxq)
2240 {
2241 	struct vtnet_rxq *rxq;
2242 
2243 	rxq = xrxq;
2244 	vtnet_rx_vq_process(rxq, VTNET_INTR_DISABLE_RETRIES);
2245 }
2246 
2247 static void
2248 vtnet_rxq_tq_intr(void *xrxq, int pending __unused)
2249 {
2250 	struct vtnet_rxq *rxq;
2251 
2252 	rxq = xrxq;
2253 	vtnet_rx_vq_process(rxq, 0);
2254 }
2255 
2256 static int
2257 vtnet_txq_intr_threshold(struct vtnet_txq *txq)
2258 {
2259 	struct vtnet_softc *sc;
2260 	int threshold;
2261 
2262 	sc = txq->vtntx_sc;
2263 
2264 	/*
2265 	 * The Tx interrupt is disabled until the queue free count falls
2266 	 * below our threshold. Completed frames are drained from the Tx
2267 	 * virtqueue before transmitting new frames and in the watchdog
2268 	 * callout, so the frequency of Tx interrupts is greatly reduced,
2269 	 * at the cost of not freeing mbufs as quickly as they otherwise
2270 	 * would be.
2271 	 */
2272 	threshold = virtqueue_size(txq->vtntx_vq) / 4;
2273 
2274 	/*
2275 	 * Without indirect descriptors, leave enough room for the most
2276 	 * segments we handle.
2277 	 */
2278 	if ((sc->vtnet_flags & VTNET_FLAG_INDIRECT) == 0 &&
2279 	    threshold < sc->vtnet_tx_nsegs)
2280 		threshold = sc->vtnet_tx_nsegs;
2281 
2282 	return (threshold);
2283 }
2284 
2285 static int
2286 vtnet_txq_below_threshold(struct vtnet_txq *txq)
2287 {
2288 	struct virtqueue *vq;
2289 
2290 	vq = txq->vtntx_vq;
2291 
2292 	return (virtqueue_nfree(vq) <= txq->vtntx_intr_threshold);
2293 }
2294 
2295 static int
2296 vtnet_txq_notify(struct vtnet_txq *txq)
2297 {
2298 	struct virtqueue *vq;
2299 
2300 	vq = txq->vtntx_vq;
2301 
2302 	txq->vtntx_watchdog = VTNET_TX_TIMEOUT;
2303 	virtqueue_notify(vq);
2304 
2305 	if (vtnet_txq_enable_intr(txq) == 0)
2306 		return (0);
2307 
2308 	/*
2309 	 * Drain frames that were completed since last checked. If this
2310 	 * causes the queue to go above the threshold, the caller should
2311 	 * continue transmitting.
2312 	 */
2313 	if (vtnet_txq_eof(txq) != 0 && vtnet_txq_below_threshold(txq) == 0) {
2314 		virtqueue_disable_intr(vq);
2315 		return (1);
2316 	}
2317 
2318 	return (0);
2319 }
2320 
2321 static void
2322 vtnet_txq_free_mbufs(struct vtnet_txq *txq)
2323 {
2324 	struct virtqueue *vq;
2325 	struct vtnet_tx_header *txhdr;
2326 	int last;
2327 #ifdef DEV_NETMAP
2328 	struct netmap_kring *kring = netmap_kring_on(NA(txq->vtntx_sc->vtnet_ifp),
2329 							txq->vtntx_id, NR_TX);
2330 #else  /* !DEV_NETMAP */
2331 	void *kring = NULL;
2332 #endif /* !DEV_NETMAP */
2333 
2334 	vq = txq->vtntx_vq;
2335 	last = 0;
2336 
2337 	while ((txhdr = virtqueue_drain(vq, &last)) != NULL) {
2338 		if (kring == NULL) {
2339 			m_freem(txhdr->vth_mbuf);
2340 			uma_zfree(vtnet_tx_header_zone, txhdr);
2341 		}
2342 	}
2343 
2344 	KASSERT(virtqueue_empty(vq),
2345 	    ("%s: mbufs remaining in tx queue %p", __func__, txq));
2346 }
2347 
2348 /*
2349  * BMV: This can go away once we finally have offsets in the mbuf header.
2350  */
2351 static int
2352 vtnet_txq_offload_ctx(struct vtnet_txq *txq, struct mbuf *m, int *etype,
2353     int *proto, int *start)
2354 {
2355 	struct vtnet_softc *sc;
2356 	struct ether_vlan_header *evh;
2357 #if defined(INET) || defined(INET6)
2358 	int offset;
2359 #endif
2360 
2361 	sc = txq->vtntx_sc;
2362 
2363 	evh = mtod(m, struct ether_vlan_header *);
2364 	if (evh->evl_encap_proto == htons(ETHERTYPE_VLAN)) {
2365 		/* BMV: We should handle nested VLAN tags too. */
2366 		*etype = ntohs(evh->evl_proto);
2367 #if defined(INET) || defined(INET6)
2368 		offset = sizeof(struct ether_vlan_header);
2369 #endif
2370 	} else {
2371 		*etype = ntohs(evh->evl_encap_proto);
2372 #if defined(INET) || defined(INET6)
2373 		offset = sizeof(struct ether_header);
2374 #endif
2375 	}
2376 
2377 	switch (*etype) {
2378 #if defined(INET)
2379 	case ETHERTYPE_IP: {
2380 		struct ip *ip, iphdr;
2381 		if (__predict_false(m->m_len < offset + sizeof(struct ip))) {
2382 			m_copydata(m, offset, sizeof(struct ip),
2383 			    (caddr_t) &iphdr);
2384 			ip = &iphdr;
2385 		} else
2386 			ip = (struct ip *)(m->m_data + offset);
2387 		*proto = ip->ip_p;
2388 		*start = offset + (ip->ip_hl << 2);
2389 		break;
2390 	}
2391 #endif
2392 #if defined(INET6)
2393 	case ETHERTYPE_IPV6:
2394 		*proto = -1;
2395 		*start = ip6_lasthdr(m, offset, IPPROTO_IPV6, proto);
2396 		/* Assert the network stack sent us a valid packet. */
2397 		KASSERT(*start > offset,
2398 		    ("%s: mbuf %p start %d offset %d proto %d", __func__, m,
2399 		    *start, offset, *proto));
2400 		break;
2401 #endif
2402 	default:
2403 		sc->vtnet_stats.tx_csum_unknown_ethtype++;
2404 		return (EINVAL);
2405 	}
2406 
2407 	return (0);
2408 }
2409 
2410 static int
2411 vtnet_txq_offload_tso(struct vtnet_txq *txq, struct mbuf *m, int eth_type,
2412     int offset, struct virtio_net_hdr *hdr)
2413 {
2414 	static struct timeval lastecn;
2415 	static int curecn;
2416 	struct vtnet_softc *sc;
2417 	struct tcphdr *tcp, tcphdr;
2418 
2419 	sc = txq->vtntx_sc;
2420 
2421 	if (__predict_false(m->m_len < offset + sizeof(struct tcphdr))) {
2422 		m_copydata(m, offset, sizeof(struct tcphdr), (caddr_t) &tcphdr);
2423 		tcp = &tcphdr;
2424 	} else
2425 		tcp = (struct tcphdr *)(m->m_data + offset);
2426 
2427 	hdr->hdr_len = vtnet_gtoh16(sc, offset + (tcp->th_off << 2));
2428 	hdr->gso_size = vtnet_gtoh16(sc, m->m_pkthdr.tso_segsz);
2429 	hdr->gso_type = eth_type == ETHERTYPE_IP ? VIRTIO_NET_HDR_GSO_TCPV4 :
2430 	    VIRTIO_NET_HDR_GSO_TCPV6;
2431 
2432 	if (__predict_false(tcp->th_flags & TH_CWR)) {
2433 		/*
2434 		 * Drop if VIRTIO_NET_F_HOST_ECN was not negotiated. In
2435 		 * FreeBSD, ECN support is not on a per-interface basis,
2436 		 * but globally via the net.inet.tcp.ecn.enable sysctl
2437 		 * knob. The default is off.
2438 		 */
2439 		if ((sc->vtnet_flags & VTNET_FLAG_TSO_ECN) == 0) {
2440 			if (ppsratecheck(&lastecn, &curecn, 1))
2441 				if_printf(sc->vtnet_ifp,
2442 				    "TSO with ECN not negotiated with host\n");
2443 			return (ENOTSUP);
2444 		}
2445 		hdr->gso_type |= VIRTIO_NET_HDR_GSO_ECN;
2446 	}
2447 
2448 	txq->vtntx_stats.vtxs_tso++;
2449 
2450 	return (0);
2451 }
2452 
2453 static struct mbuf *
2454 vtnet_txq_offload(struct vtnet_txq *txq, struct mbuf *m,
2455     struct virtio_net_hdr *hdr)
2456 {
2457 	struct vtnet_softc *sc;
2458 	int flags, etype, csum_start, proto, error;
2459 
2460 	sc = txq->vtntx_sc;
2461 	flags = m->m_pkthdr.csum_flags;
2462 
2463 	error = vtnet_txq_offload_ctx(txq, m, &etype, &proto, &csum_start);
2464 	if (error)
2465 		goto drop;
2466 
2467 	if (flags & (VTNET_CSUM_OFFLOAD | VTNET_CSUM_OFFLOAD_IPV6)) {
2468 		/* Sanity check the parsed mbuf matches the offload flags. */
2469 		if (__predict_false((flags & VTNET_CSUM_OFFLOAD &&
2470 		    etype != ETHERTYPE_IP) || (flags & VTNET_CSUM_OFFLOAD_IPV6
2471 		    && etype != ETHERTYPE_IPV6))) {
2472 			sc->vtnet_stats.tx_csum_proto_mismatch++;
2473 			goto drop;
2474 		}
2475 
2476 		hdr->flags |= VIRTIO_NET_HDR_F_NEEDS_CSUM;
2477 		hdr->csum_start = vtnet_gtoh16(sc, csum_start);
2478 		hdr->csum_offset = vtnet_gtoh16(sc, m->m_pkthdr.csum_data);
2479 		txq->vtntx_stats.vtxs_csum++;
2480 	}
2481 
2482 	if (flags & (CSUM_IP_TSO | CSUM_IP6_TSO)) {
2483 		/*
2484 		 * Sanity check the parsed mbuf IP protocol is TCP, and
2485 		 * VirtIO TSO reqires the checksum offloading above.
2486 		 */
2487 		if (__predict_false(proto != IPPROTO_TCP)) {
2488 			sc->vtnet_stats.tx_tso_not_tcp++;
2489 			goto drop;
2490 		} else if (__predict_false((hdr->flags &
2491 		    VIRTIO_NET_HDR_F_NEEDS_CSUM) == 0)) {
2492 			sc->vtnet_stats.tx_tso_without_csum++;
2493 			goto drop;
2494 		}
2495 
2496 		error = vtnet_txq_offload_tso(txq, m, etype, csum_start, hdr);
2497 		if (error)
2498 			goto drop;
2499 	}
2500 
2501 	return (m);
2502 
2503 drop:
2504 	m_freem(m);
2505 	return (NULL);
2506 }
2507 
2508 static int
2509 vtnet_txq_enqueue_buf(struct vtnet_txq *txq, struct mbuf **m_head,
2510     struct vtnet_tx_header *txhdr)
2511 {
2512 	struct vtnet_softc *sc;
2513 	struct virtqueue *vq;
2514 	struct sglist *sg;
2515 	struct mbuf *m;
2516 	int error;
2517 
2518 	sc = txq->vtntx_sc;
2519 	vq = txq->vtntx_vq;
2520 	sg = txq->vtntx_sg;
2521 	m = *m_head;
2522 
2523 	sglist_reset(sg);
2524 	error = sglist_append(sg, &txhdr->vth_uhdr, sc->vtnet_hdr_size);
2525 	if (error != 0 || sg->sg_nseg != 1) {
2526 		KASSERT(0, ("%s: cannot add header to sglist error %d nseg %d",
2527 		    __func__, error, sg->sg_nseg));
2528 		goto fail;
2529 	}
2530 
2531 	error = sglist_append_mbuf(sg, m);
2532 	if (error) {
2533 		m = m_defrag(m, M_NOWAIT);
2534 		if (m == NULL)
2535 			goto fail;
2536 
2537 		*m_head = m;
2538 		sc->vtnet_stats.tx_defragged++;
2539 
2540 		error = sglist_append_mbuf(sg, m);
2541 		if (error)
2542 			goto fail;
2543 	}
2544 
2545 	txhdr->vth_mbuf = m;
2546 	error = virtqueue_enqueue(vq, txhdr, sg, sg->sg_nseg, 0);
2547 
2548 	return (error);
2549 
2550 fail:
2551 	sc->vtnet_stats.tx_defrag_failed++;
2552 	m_freem(*m_head);
2553 	*m_head = NULL;
2554 
2555 	return (ENOBUFS);
2556 }
2557 
2558 static int
2559 vtnet_txq_encap(struct vtnet_txq *txq, struct mbuf **m_head, int flags)
2560 {
2561 	struct vtnet_tx_header *txhdr;
2562 	struct virtio_net_hdr *hdr;
2563 	struct mbuf *m;
2564 	int error;
2565 
2566 	m = *m_head;
2567 	M_ASSERTPKTHDR(m);
2568 
2569 	txhdr = uma_zalloc(vtnet_tx_header_zone, flags | M_ZERO);
2570 	if (txhdr == NULL) {
2571 		m_freem(m);
2572 		*m_head = NULL;
2573 		return (ENOMEM);
2574 	}
2575 
2576 	/*
2577 	 * Always use the non-mergeable header, regardless if mergable headers
2578 	 * were negotiated, because for transmit num_buffers is always zero.
2579 	 * The vtnet_hdr_size is used to enqueue the right header size segment.
2580 	 */
2581 	hdr = &txhdr->vth_uhdr.hdr;
2582 
2583 	if (m->m_flags & M_VLANTAG) {
2584 		m = ether_vlanencap(m, m->m_pkthdr.ether_vtag);
2585 		if ((*m_head = m) == NULL) {
2586 			error = ENOBUFS;
2587 			goto fail;
2588 		}
2589 		m->m_flags &= ~M_VLANTAG;
2590 	}
2591 
2592 	if (m->m_pkthdr.csum_flags & VTNET_CSUM_ALL_OFFLOAD) {
2593 		m = vtnet_txq_offload(txq, m, hdr);
2594 		if ((*m_head = m) == NULL) {
2595 			error = ENOBUFS;
2596 			goto fail;
2597 		}
2598 	}
2599 
2600 	error = vtnet_txq_enqueue_buf(txq, m_head, txhdr);
2601 fail:
2602 	if (error)
2603 		uma_zfree(vtnet_tx_header_zone, txhdr);
2604 
2605 	return (error);
2606 }
2607 
2608 #ifdef VTNET_LEGACY_TX
2609 
2610 static void
2611 vtnet_start_locked(struct vtnet_txq *txq, if_t ifp)
2612 {
2613 	struct vtnet_softc *sc;
2614 	struct virtqueue *vq;
2615 	struct mbuf *m0;
2616 	int tries, enq;
2617 
2618 	sc = txq->vtntx_sc;
2619 	vq = txq->vtntx_vq;
2620 	tries = 0;
2621 
2622 	VTNET_TXQ_LOCK_ASSERT(txq);
2623 
2624 	if ((if_getdrvflags(ifp) & IFF_DRV_RUNNING) == 0 ||
2625 	    sc->vtnet_link_active == 0)
2626 		return;
2627 
2628 	vtnet_txq_eof(txq);
2629 
2630 again:
2631 	enq = 0;
2632 
2633 	while (!if_sendq_empty(ifp)) {
2634 		if (virtqueue_full(vq))
2635 			break;
2636 
2637 		m0 = if_dequeue(ifp);
2638 		if (m0 == NULL)
2639 			break;
2640 
2641 		if (vtnet_txq_encap(txq, &m0, M_NOWAIT) != 0) {
2642 			if (m0 != NULL)
2643 				if_sendq_prepend(ifp, m0);
2644 			break;
2645 		}
2646 
2647 		enq++;
2648 		ETHER_BPF_MTAP(ifp, m0);
2649 	}
2650 
2651 	if (enq > 0 && vtnet_txq_notify(txq) != 0) {
2652 		if (tries++ < VTNET_NOTIFY_RETRIES)
2653 			goto again;
2654 
2655 		txq->vtntx_stats.vtxs_rescheduled++;
2656 		taskqueue_enqueue(txq->vtntx_tq, &txq->vtntx_intrtask);
2657 	}
2658 }
2659 
2660 static void
2661 vtnet_start(if_t ifp)
2662 {
2663 	struct vtnet_softc *sc;
2664 	struct vtnet_txq *txq;
2665 
2666 	sc = if_getsoftc(ifp);
2667 	txq = &sc->vtnet_txqs[0];
2668 
2669 	VTNET_TXQ_LOCK(txq);
2670 	vtnet_start_locked(txq, ifp);
2671 	VTNET_TXQ_UNLOCK(txq);
2672 }
2673 
2674 #else /* !VTNET_LEGACY_TX */
2675 
2676 static int
2677 vtnet_txq_mq_start_locked(struct vtnet_txq *txq, struct mbuf *m)
2678 {
2679 	struct vtnet_softc *sc;
2680 	struct virtqueue *vq;
2681 	struct buf_ring *br;
2682 	if_t ifp;
2683 	int enq, tries, error;
2684 
2685 	sc = txq->vtntx_sc;
2686 	vq = txq->vtntx_vq;
2687 	br = txq->vtntx_br;
2688 	ifp = sc->vtnet_ifp;
2689 	tries = 0;
2690 	error = 0;
2691 
2692 	VTNET_TXQ_LOCK_ASSERT(txq);
2693 
2694 	if ((if_getdrvflags(ifp) & IFF_DRV_RUNNING) == 0 ||
2695 	    sc->vtnet_link_active == 0) {
2696 		if (m != NULL)
2697 			error = drbr_enqueue(ifp, br, m);
2698 		return (error);
2699 	}
2700 
2701 	if (m != NULL) {
2702 		error = drbr_enqueue(ifp, br, m);
2703 		if (error)
2704 			return (error);
2705 	}
2706 
2707 	vtnet_txq_eof(txq);
2708 
2709 again:
2710 	enq = 0;
2711 
2712 	while ((m = drbr_peek(ifp, br)) != NULL) {
2713 		if (virtqueue_full(vq)) {
2714 			drbr_putback(ifp, br, m);
2715 			break;
2716 		}
2717 
2718 		if (vtnet_txq_encap(txq, &m, M_NOWAIT) != 0) {
2719 			if (m != NULL)
2720 				drbr_putback(ifp, br, m);
2721 			else
2722 				drbr_advance(ifp, br);
2723 			break;
2724 		}
2725 		drbr_advance(ifp, br);
2726 
2727 		enq++;
2728 		ETHER_BPF_MTAP(ifp, m);
2729 	}
2730 
2731 	if (enq > 0 && vtnet_txq_notify(txq) != 0) {
2732 		if (tries++ < VTNET_NOTIFY_RETRIES)
2733 			goto again;
2734 
2735 		txq->vtntx_stats.vtxs_rescheduled++;
2736 		taskqueue_enqueue(txq->vtntx_tq, &txq->vtntx_intrtask);
2737 	}
2738 
2739 	return (0);
2740 }
2741 
2742 static int
2743 vtnet_txq_mq_start(if_t ifp, struct mbuf *m)
2744 {
2745 	struct vtnet_softc *sc;
2746 	struct vtnet_txq *txq;
2747 	int i, npairs, error;
2748 
2749 	sc = if_getsoftc(ifp);
2750 	npairs = sc->vtnet_act_vq_pairs;
2751 
2752 	if (M_HASHTYPE_GET(m) != M_HASHTYPE_NONE)
2753 		i = m->m_pkthdr.flowid % npairs;
2754 	else
2755 		i = curcpu % npairs;
2756 
2757 	txq = &sc->vtnet_txqs[i];
2758 
2759 	if (VTNET_TXQ_TRYLOCK(txq) != 0) {
2760 		error = vtnet_txq_mq_start_locked(txq, m);
2761 		VTNET_TXQ_UNLOCK(txq);
2762 	} else {
2763 		error = drbr_enqueue(ifp, txq->vtntx_br, m);
2764 		taskqueue_enqueue(txq->vtntx_tq, &txq->vtntx_defrtask);
2765 	}
2766 
2767 	return (error);
2768 }
2769 
2770 static void
2771 vtnet_txq_tq_deferred(void *xtxq, int pending __unused)
2772 {
2773 	struct vtnet_softc *sc;
2774 	struct vtnet_txq *txq;
2775 
2776 	txq = xtxq;
2777 	sc = txq->vtntx_sc;
2778 
2779 	VTNET_TXQ_LOCK(txq);
2780 	if (!drbr_empty(sc->vtnet_ifp, txq->vtntx_br))
2781 		vtnet_txq_mq_start_locked(txq, NULL);
2782 	VTNET_TXQ_UNLOCK(txq);
2783 }
2784 
2785 #endif /* VTNET_LEGACY_TX */
2786 
2787 static void
2788 vtnet_txq_start(struct vtnet_txq *txq)
2789 {
2790 	struct vtnet_softc *sc;
2791 	if_t ifp;
2792 
2793 	sc = txq->vtntx_sc;
2794 	ifp = sc->vtnet_ifp;
2795 
2796 #ifdef VTNET_LEGACY_TX
2797 	if (!if_sendq_empty(ifp))
2798 		vtnet_start_locked(txq, ifp);
2799 #else
2800 	if (!drbr_empty(ifp, txq->vtntx_br))
2801 		vtnet_txq_mq_start_locked(txq, NULL);
2802 #endif
2803 }
2804 
2805 static void
2806 vtnet_txq_tq_intr(void *xtxq, int pending __unused)
2807 {
2808 	struct vtnet_softc *sc;
2809 	struct vtnet_txq *txq;
2810 	if_t ifp;
2811 
2812 	txq = xtxq;
2813 	sc = txq->vtntx_sc;
2814 	ifp = sc->vtnet_ifp;
2815 
2816 	VTNET_TXQ_LOCK(txq);
2817 
2818 	if ((if_getdrvflags(ifp) & IFF_DRV_RUNNING) == 0) {
2819 		VTNET_TXQ_UNLOCK(txq);
2820 		return;
2821 	}
2822 
2823 	vtnet_txq_eof(txq);
2824 	vtnet_txq_start(txq);
2825 
2826 	VTNET_TXQ_UNLOCK(txq);
2827 }
2828 
2829 static int
2830 vtnet_txq_eof(struct vtnet_txq *txq)
2831 {
2832 	struct virtqueue *vq;
2833 	struct vtnet_tx_header *txhdr;
2834 	struct mbuf *m;
2835 	int deq;
2836 
2837 	vq = txq->vtntx_vq;
2838 	deq = 0;
2839 	VTNET_TXQ_LOCK_ASSERT(txq);
2840 
2841 	while ((txhdr = virtqueue_dequeue(vq, NULL)) != NULL) {
2842 		m = txhdr->vth_mbuf;
2843 		deq++;
2844 
2845 		txq->vtntx_stats.vtxs_opackets++;
2846 		txq->vtntx_stats.vtxs_obytes += m->m_pkthdr.len;
2847 		if (m->m_flags & M_MCAST)
2848 			txq->vtntx_stats.vtxs_omcasts++;
2849 
2850 		m_freem(m);
2851 		uma_zfree(vtnet_tx_header_zone, txhdr);
2852 	}
2853 
2854 	if (virtqueue_empty(vq))
2855 		txq->vtntx_watchdog = 0;
2856 
2857 	return (deq);
2858 }
2859 
2860 static void
2861 vtnet_tx_vq_intr(void *xtxq)
2862 {
2863 	struct vtnet_softc *sc;
2864 	struct vtnet_txq *txq;
2865 	if_t ifp;
2866 
2867 	txq = xtxq;
2868 	sc = txq->vtntx_sc;
2869 	ifp = sc->vtnet_ifp;
2870 
2871 	if (__predict_false(txq->vtntx_id >= sc->vtnet_act_vq_pairs)) {
2872 		/*
2873 		 * Ignore this interrupt. Either this is a spurious interrupt
2874 		 * or multiqueue without per-VQ MSIX so every queue needs to
2875 		 * be polled (a brain dead configuration we could try harder
2876 		 * to avoid).
2877 		 */
2878 		vtnet_txq_disable_intr(txq);
2879 		return;
2880 	}
2881 
2882 #ifdef DEV_NETMAP
2883 	if (netmap_tx_irq(ifp, txq->vtntx_id) != NM_IRQ_PASS)
2884 		return;
2885 #endif /* DEV_NETMAP */
2886 
2887 	VTNET_TXQ_LOCK(txq);
2888 
2889 	if ((if_getdrvflags(ifp) & IFF_DRV_RUNNING) == 0) {
2890 		VTNET_TXQ_UNLOCK(txq);
2891 		return;
2892 	}
2893 
2894 	vtnet_txq_eof(txq);
2895 	vtnet_txq_start(txq);
2896 
2897 	VTNET_TXQ_UNLOCK(txq);
2898 }
2899 
2900 static void
2901 vtnet_tx_start_all(struct vtnet_softc *sc)
2902 {
2903 	struct vtnet_txq *txq;
2904 	int i;
2905 
2906 	VTNET_CORE_LOCK_ASSERT(sc);
2907 
2908 	for (i = 0; i < sc->vtnet_act_vq_pairs; i++) {
2909 		txq = &sc->vtnet_txqs[i];
2910 
2911 		VTNET_TXQ_LOCK(txq);
2912 		vtnet_txq_start(txq);
2913 		VTNET_TXQ_UNLOCK(txq);
2914 	}
2915 }
2916 
2917 #ifndef VTNET_LEGACY_TX
2918 static void
2919 vtnet_qflush(if_t ifp)
2920 {
2921 	struct vtnet_softc *sc;
2922 	struct vtnet_txq *txq;
2923 	struct mbuf *m;
2924 	int i;
2925 
2926 	sc = if_getsoftc(ifp);
2927 
2928 	for (i = 0; i < sc->vtnet_act_vq_pairs; i++) {
2929 		txq = &sc->vtnet_txqs[i];
2930 
2931 		VTNET_TXQ_LOCK(txq);
2932 		while ((m = buf_ring_dequeue_sc(txq->vtntx_br)) != NULL)
2933 			m_freem(m);
2934 		VTNET_TXQ_UNLOCK(txq);
2935 	}
2936 
2937 	if_qflush(ifp);
2938 }
2939 #endif
2940 
2941 static int
2942 vtnet_watchdog(struct vtnet_txq *txq)
2943 {
2944 	if_t ifp;
2945 
2946 	ifp = txq->vtntx_sc->vtnet_ifp;
2947 
2948 	VTNET_TXQ_LOCK(txq);
2949 	if (txq->vtntx_watchdog == 1) {
2950 		/*
2951 		 * Only drain completed frames if the watchdog is about to
2952 		 * expire. If any frames were drained, there may be enough
2953 		 * free descriptors now available to transmit queued frames.
2954 		 * In that case, the timer will immediately be decremented
2955 		 * below, but the timeout is generous enough that should not
2956 		 * be a problem.
2957 		 */
2958 		if (vtnet_txq_eof(txq) != 0)
2959 			vtnet_txq_start(txq);
2960 	}
2961 
2962 	if (txq->vtntx_watchdog == 0 || --txq->vtntx_watchdog) {
2963 		VTNET_TXQ_UNLOCK(txq);
2964 		return (0);
2965 	}
2966 	VTNET_TXQ_UNLOCK(txq);
2967 
2968 	if_printf(ifp, "watchdog timeout on queue %d\n", txq->vtntx_id);
2969 	return (1);
2970 }
2971 
2972 static void
2973 vtnet_accum_stats(struct vtnet_softc *sc, struct vtnet_rxq_stats *rxacc,
2974     struct vtnet_txq_stats *txacc)
2975 {
2976 
2977 	bzero(rxacc, sizeof(struct vtnet_rxq_stats));
2978 	bzero(txacc, sizeof(struct vtnet_txq_stats));
2979 
2980 	for (int i = 0; i < sc->vtnet_max_vq_pairs; i++) {
2981 		struct vtnet_rxq_stats *rxst;
2982 		struct vtnet_txq_stats *txst;
2983 
2984 		rxst = &sc->vtnet_rxqs[i].vtnrx_stats;
2985 		rxacc->vrxs_ipackets += rxst->vrxs_ipackets;
2986 		rxacc->vrxs_ibytes += rxst->vrxs_ibytes;
2987 		rxacc->vrxs_iqdrops += rxst->vrxs_iqdrops;
2988 		rxacc->vrxs_csum += rxst->vrxs_csum;
2989 		rxacc->vrxs_csum_failed += rxst->vrxs_csum_failed;
2990 		rxacc->vrxs_rescheduled += rxst->vrxs_rescheduled;
2991 
2992 		txst = &sc->vtnet_txqs[i].vtntx_stats;
2993 		txacc->vtxs_opackets += txst->vtxs_opackets;
2994 		txacc->vtxs_obytes += txst->vtxs_obytes;
2995 		txacc->vtxs_csum += txst->vtxs_csum;
2996 		txacc->vtxs_tso += txst->vtxs_tso;
2997 		txacc->vtxs_rescheduled += txst->vtxs_rescheduled;
2998 	}
2999 }
3000 
3001 static uint64_t
3002 vtnet_get_counter(if_t ifp, ift_counter cnt)
3003 {
3004 	struct vtnet_softc *sc;
3005 	struct vtnet_rxq_stats rxaccum;
3006 	struct vtnet_txq_stats txaccum;
3007 
3008 	sc = if_getsoftc(ifp);
3009 	vtnet_accum_stats(sc, &rxaccum, &txaccum);
3010 
3011 	switch (cnt) {
3012 	case IFCOUNTER_IPACKETS:
3013 		return (rxaccum.vrxs_ipackets);
3014 	case IFCOUNTER_IQDROPS:
3015 		return (rxaccum.vrxs_iqdrops);
3016 	case IFCOUNTER_IERRORS:
3017 		return (rxaccum.vrxs_ierrors);
3018 	case IFCOUNTER_OPACKETS:
3019 		return (txaccum.vtxs_opackets);
3020 #ifndef VTNET_LEGACY_TX
3021 	case IFCOUNTER_OBYTES:
3022 		return (txaccum.vtxs_obytes);
3023 	case IFCOUNTER_OMCASTS:
3024 		return (txaccum.vtxs_omcasts);
3025 #endif
3026 	default:
3027 		return (if_get_counter_default(ifp, cnt));
3028 	}
3029 }
3030 
3031 static void
3032 vtnet_tick(void *xsc)
3033 {
3034 	struct vtnet_softc *sc;
3035 	if_t ifp;
3036 	int i, timedout;
3037 
3038 	sc = xsc;
3039 	ifp = sc->vtnet_ifp;
3040 	timedout = 0;
3041 
3042 	VTNET_CORE_LOCK_ASSERT(sc);
3043 
3044 	for (i = 0; i < sc->vtnet_act_vq_pairs; i++)
3045 		timedout |= vtnet_watchdog(&sc->vtnet_txqs[i]);
3046 
3047 	if (timedout != 0) {
3048 		if_setdrvflagbits(ifp, 0, IFF_DRV_RUNNING);
3049 		vtnet_init_locked(sc, 0);
3050 	} else
3051 		callout_schedule(&sc->vtnet_tick_ch, hz);
3052 }
3053 
3054 static void
3055 vtnet_start_taskqueues(struct vtnet_softc *sc)
3056 {
3057 	device_t dev;
3058 	struct vtnet_rxq *rxq;
3059 	struct vtnet_txq *txq;
3060 	int i, error;
3061 
3062 	dev = sc->vtnet_dev;
3063 
3064 	/*
3065 	 * Errors here are very difficult to recover from - we cannot
3066 	 * easily fail because, if this is during boot, we will hang
3067 	 * when freeing any successfully started taskqueues because
3068 	 * the scheduler isn't up yet.
3069 	 *
3070 	 * Most drivers just ignore the return value - it only fails
3071 	 * with ENOMEM so an error is not likely.
3072 	 */
3073 	for (i = 0; i < sc->vtnet_req_vq_pairs; i++) {
3074 		rxq = &sc->vtnet_rxqs[i];
3075 		error = taskqueue_start_threads(&rxq->vtnrx_tq, 1, PI_NET,
3076 		    "%s rxq %d", device_get_nameunit(dev), rxq->vtnrx_id);
3077 		if (error) {
3078 			device_printf(dev, "failed to start rx taskq %d\n",
3079 			    rxq->vtnrx_id);
3080 		}
3081 
3082 		txq = &sc->vtnet_txqs[i];
3083 		error = taskqueue_start_threads(&txq->vtntx_tq, 1, PI_NET,
3084 		    "%s txq %d", device_get_nameunit(dev), txq->vtntx_id);
3085 		if (error) {
3086 			device_printf(dev, "failed to start tx taskq %d\n",
3087 			    txq->vtntx_id);
3088 		}
3089 	}
3090 }
3091 
3092 static void
3093 vtnet_free_taskqueues(struct vtnet_softc *sc)
3094 {
3095 	struct vtnet_rxq *rxq;
3096 	struct vtnet_txq *txq;
3097 	int i;
3098 
3099 	for (i = 0; i < sc->vtnet_max_vq_pairs; i++) {
3100 		rxq = &sc->vtnet_rxqs[i];
3101 		if (rxq->vtnrx_tq != NULL) {
3102 			taskqueue_free(rxq->vtnrx_tq);
3103 			rxq->vtnrx_tq = NULL;
3104 		}
3105 
3106 		txq = &sc->vtnet_txqs[i];
3107 		if (txq->vtntx_tq != NULL) {
3108 			taskqueue_free(txq->vtntx_tq);
3109 			txq->vtntx_tq = NULL;
3110 		}
3111 	}
3112 }
3113 
3114 static void
3115 vtnet_drain_taskqueues(struct vtnet_softc *sc)
3116 {
3117 	struct vtnet_rxq *rxq;
3118 	struct vtnet_txq *txq;
3119 	int i;
3120 
3121 	for (i = 0; i < sc->vtnet_max_vq_pairs; i++) {
3122 		rxq = &sc->vtnet_rxqs[i];
3123 		if (rxq->vtnrx_tq != NULL)
3124 			taskqueue_drain(rxq->vtnrx_tq, &rxq->vtnrx_intrtask);
3125 
3126 		txq = &sc->vtnet_txqs[i];
3127 		if (txq->vtntx_tq != NULL) {
3128 			taskqueue_drain(txq->vtntx_tq, &txq->vtntx_intrtask);
3129 #ifndef VTNET_LEGACY_TX
3130 			taskqueue_drain(txq->vtntx_tq, &txq->vtntx_defrtask);
3131 #endif
3132 		}
3133 	}
3134 }
3135 
3136 static void
3137 vtnet_drain_rxtx_queues(struct vtnet_softc *sc)
3138 {
3139 	struct vtnet_rxq *rxq;
3140 	struct vtnet_txq *txq;
3141 	int i;
3142 
3143 	for (i = 0; i < sc->vtnet_max_vq_pairs; i++) {
3144 		rxq = &sc->vtnet_rxqs[i];
3145 		vtnet_rxq_free_mbufs(rxq);
3146 
3147 		txq = &sc->vtnet_txqs[i];
3148 		vtnet_txq_free_mbufs(txq);
3149 	}
3150 }
3151 
3152 static void
3153 vtnet_stop_rendezvous(struct vtnet_softc *sc)
3154 {
3155 	struct vtnet_rxq *rxq;
3156 	struct vtnet_txq *txq;
3157 	int i;
3158 
3159 	VTNET_CORE_LOCK_ASSERT(sc);
3160 
3161 	/*
3162 	 * Lock and unlock the per-queue mutex so we known the stop
3163 	 * state is visible. Doing only the active queues should be
3164 	 * sufficient, but it does not cost much extra to do all the
3165 	 * queues.
3166 	 */
3167 	for (i = 0; i < sc->vtnet_max_vq_pairs; i++) {
3168 		rxq = &sc->vtnet_rxqs[i];
3169 		VTNET_RXQ_LOCK(rxq);
3170 		VTNET_RXQ_UNLOCK(rxq);
3171 
3172 		txq = &sc->vtnet_txqs[i];
3173 		VTNET_TXQ_LOCK(txq);
3174 		VTNET_TXQ_UNLOCK(txq);
3175 	}
3176 }
3177 
3178 static void
3179 vtnet_stop(struct vtnet_softc *sc)
3180 {
3181 	device_t dev;
3182 	if_t ifp;
3183 
3184 	dev = sc->vtnet_dev;
3185 	ifp = sc->vtnet_ifp;
3186 
3187 	VTNET_CORE_LOCK_ASSERT(sc);
3188 
3189 	if_setdrvflagbits(ifp, 0, IFF_DRV_RUNNING);
3190 	sc->vtnet_link_active = 0;
3191 	callout_stop(&sc->vtnet_tick_ch);
3192 
3193 	/* Only advisory. */
3194 	vtnet_disable_interrupts(sc);
3195 
3196 #ifdef DEV_NETMAP
3197 	/* Stop any pending txsync/rxsync and disable them. */
3198 	netmap_disable_all_rings(ifp);
3199 #endif /* DEV_NETMAP */
3200 
3201 	/*
3202 	 * Stop the host adapter. This resets it to the pre-initialized
3203 	 * state. It will not generate any interrupts until after it is
3204 	 * reinitialized.
3205 	 */
3206 	virtio_stop(dev);
3207 	vtnet_stop_rendezvous(sc);
3208 
3209 	vtnet_drain_rxtx_queues(sc);
3210 	sc->vtnet_act_vq_pairs = 1;
3211 }
3212 
3213 static int
3214 vtnet_virtio_reinit(struct vtnet_softc *sc)
3215 {
3216 	device_t dev;
3217 	if_t ifp;
3218 	uint64_t features;
3219 	int error;
3220 
3221 	dev = sc->vtnet_dev;
3222 	ifp = sc->vtnet_ifp;
3223 	features = sc->vtnet_negotiated_features;
3224 
3225 	/*
3226 	 * Re-negotiate with the host, removing any disabled receive
3227 	 * features. Transmit features are disabled only on our side
3228 	 * via if_capenable and if_hwassist.
3229 	 */
3230 
3231 	if ((if_getcapenable(ifp) & (IFCAP_RXCSUM | IFCAP_RXCSUM_IPV6)) == 0)
3232 		features &= ~(VIRTIO_NET_F_GUEST_CSUM | VTNET_LRO_FEATURES);
3233 
3234 	if ((if_getcapenable(ifp) & IFCAP_LRO) == 0)
3235 		features &= ~VTNET_LRO_FEATURES;
3236 
3237 	if ((if_getcapenable(ifp) & IFCAP_VLAN_HWFILTER) == 0)
3238 		features &= ~VIRTIO_NET_F_CTRL_VLAN;
3239 
3240 	error = virtio_reinit(dev, features);
3241 	if (error) {
3242 		device_printf(dev, "virtio reinit error %d\n", error);
3243 		return (error);
3244 	}
3245 
3246 	sc->vtnet_features = features;
3247 	virtio_reinit_complete(dev);
3248 
3249 	return (0);
3250 }
3251 
3252 static void
3253 vtnet_init_rx_filters(struct vtnet_softc *sc)
3254 {
3255 	if_t ifp;
3256 
3257 	ifp = sc->vtnet_ifp;
3258 
3259 	if (sc->vtnet_flags & VTNET_FLAG_CTRL_RX) {
3260 		vtnet_rx_filter(sc);
3261 		vtnet_rx_filter_mac(sc);
3262 	}
3263 
3264 	if (if_getcapenable(ifp) & IFCAP_VLAN_HWFILTER)
3265 		vtnet_rx_filter_vlan(sc);
3266 }
3267 
3268 static int
3269 vtnet_init_rx_queues(struct vtnet_softc *sc)
3270 {
3271 	device_t dev;
3272 	if_t ifp;
3273 	struct vtnet_rxq *rxq;
3274 	int i, clustersz, error;
3275 
3276 	dev = sc->vtnet_dev;
3277 	ifp = sc->vtnet_ifp;
3278 
3279 	clustersz = vtnet_rx_cluster_size(sc, if_getmtu(ifp));
3280 	sc->vtnet_rx_clustersz = clustersz;
3281 
3282 	if (sc->vtnet_flags & VTNET_FLAG_LRO_NOMRG) {
3283 		sc->vtnet_rx_nmbufs = howmany(sizeof(struct vtnet_rx_header) +
3284 		    VTNET_MAX_RX_SIZE, clustersz);
3285 		KASSERT(sc->vtnet_rx_nmbufs < sc->vtnet_rx_nsegs,
3286 		    ("%s: too many rx mbufs %d for %d segments", __func__,
3287 		    sc->vtnet_rx_nmbufs, sc->vtnet_rx_nsegs));
3288 	} else
3289 		sc->vtnet_rx_nmbufs = 1;
3290 
3291 	for (i = 0; i < sc->vtnet_act_vq_pairs; i++) {
3292 		rxq = &sc->vtnet_rxqs[i];
3293 
3294 		/* Hold the lock to satisfy asserts. */
3295 		VTNET_RXQ_LOCK(rxq);
3296 		error = vtnet_rxq_populate(rxq);
3297 		VTNET_RXQ_UNLOCK(rxq);
3298 
3299 		if (error) {
3300 			device_printf(dev, "cannot populate Rx queue %d\n", i);
3301 			return (error);
3302 		}
3303 	}
3304 
3305 	return (0);
3306 }
3307 
3308 static int
3309 vtnet_init_tx_queues(struct vtnet_softc *sc)
3310 {
3311 	struct vtnet_txq *txq;
3312 	int i;
3313 
3314 	for (i = 0; i < sc->vtnet_act_vq_pairs; i++) {
3315 		txq = &sc->vtnet_txqs[i];
3316 		txq->vtntx_watchdog = 0;
3317 		txq->vtntx_intr_threshold = vtnet_txq_intr_threshold(txq);
3318 #ifdef DEV_NETMAP
3319 		netmap_reset(NA(sc->vtnet_ifp), NR_TX, i, 0);
3320 #endif /* DEV_NETMAP */
3321 	}
3322 
3323 	return (0);
3324 }
3325 
3326 static int
3327 vtnet_init_rxtx_queues(struct vtnet_softc *sc)
3328 {
3329 	int error;
3330 
3331 	error = vtnet_init_rx_queues(sc);
3332 	if (error)
3333 		return (error);
3334 
3335 	error = vtnet_init_tx_queues(sc);
3336 	if (error)
3337 		return (error);
3338 
3339 	return (0);
3340 }
3341 
3342 static void
3343 vtnet_set_active_vq_pairs(struct vtnet_softc *sc)
3344 {
3345 	device_t dev;
3346 	int npairs;
3347 
3348 	dev = sc->vtnet_dev;
3349 
3350 	if ((sc->vtnet_flags & VTNET_FLAG_MQ) == 0) {
3351 		sc->vtnet_act_vq_pairs = 1;
3352 		return;
3353 	}
3354 
3355 	npairs = sc->vtnet_req_vq_pairs;
3356 
3357 	if (vtnet_ctrl_mq_cmd(sc, npairs) != 0) {
3358 		device_printf(dev, "cannot set active queue pairs to %d, "
3359 		    "falling back to 1 queue pair\n", npairs);
3360 		npairs = 1;
3361 	}
3362 
3363 	sc->vtnet_act_vq_pairs = npairs;
3364 }
3365 
3366 static void
3367 vtnet_update_rx_offloads(struct vtnet_softc *sc)
3368 {
3369 	if_t ifp;
3370 	uint64_t features;
3371 	int error;
3372 
3373 	ifp = sc->vtnet_ifp;
3374 	features = sc->vtnet_features;
3375 
3376 	VTNET_CORE_LOCK_ASSERT(sc);
3377 
3378 	if (if_getcapabilities(ifp) & (IFCAP_RXCSUM | IFCAP_RXCSUM_IPV6)) {
3379 		if (if_getcapenable(ifp) & (IFCAP_RXCSUM | IFCAP_RXCSUM_IPV6))
3380 			features |= VIRTIO_NET_F_GUEST_CSUM;
3381 		else
3382 			features &= ~VIRTIO_NET_F_GUEST_CSUM;
3383 	}
3384 
3385 	if (if_getcapabilities(ifp) & IFCAP_LRO && !vtnet_software_lro(sc)) {
3386 		if (if_getcapenable(ifp) & IFCAP_LRO)
3387 			features |= VTNET_LRO_FEATURES;
3388 		else
3389 			features &= ~VTNET_LRO_FEATURES;
3390 	}
3391 
3392 	error = vtnet_ctrl_guest_offloads(sc,
3393 	    features & (VIRTIO_NET_F_GUEST_CSUM | VIRTIO_NET_F_GUEST_TSO4 |
3394 		        VIRTIO_NET_F_GUEST_TSO6 | VIRTIO_NET_F_GUEST_ECN  |
3395 			VIRTIO_NET_F_GUEST_UFO));
3396 	if (error) {
3397 		device_printf(sc->vtnet_dev,
3398 		    "%s: cannot update Rx features\n", __func__);
3399 		if (if_getdrvflags(ifp) & IFF_DRV_RUNNING) {
3400 			if_setdrvflagbits(ifp, 0, IFF_DRV_RUNNING);
3401 			vtnet_init_locked(sc, 0);
3402 		}
3403 	} else
3404 		sc->vtnet_features = features;
3405 }
3406 
3407 static int
3408 vtnet_reinit(struct vtnet_softc *sc)
3409 {
3410 	if_t ifp;
3411 	int error;
3412 
3413 	ifp = sc->vtnet_ifp;
3414 
3415 	bcopy(if_getlladdr(ifp), sc->vtnet_hwaddr, ETHER_ADDR_LEN);
3416 
3417 	error = vtnet_virtio_reinit(sc);
3418 	if (error)
3419 		return (error);
3420 
3421 	vtnet_set_macaddr(sc);
3422 	vtnet_set_active_vq_pairs(sc);
3423 
3424 	if (sc->vtnet_flags & VTNET_FLAG_CTRL_VQ)
3425 		vtnet_init_rx_filters(sc);
3426 
3427 	if_sethwassist(ifp, 0);
3428 	if (if_getcapenable(ifp) & IFCAP_TXCSUM)
3429 		if_sethwassistbits(ifp, VTNET_CSUM_OFFLOAD, 0);
3430 	if (if_getcapenable(ifp) & IFCAP_TXCSUM_IPV6)
3431 		if_sethwassistbits(ifp, VTNET_CSUM_OFFLOAD_IPV6, 0);
3432 	if (if_getcapenable(ifp) & IFCAP_TSO4)
3433 		if_sethwassistbits(ifp, CSUM_IP_TSO, 0);
3434 	if (if_getcapenable(ifp) & IFCAP_TSO6)
3435 		if_sethwassistbits(ifp, CSUM_IP6_TSO, 0);
3436 
3437 	error = vtnet_init_rxtx_queues(sc);
3438 	if (error)
3439 		return (error);
3440 
3441 	return (0);
3442 }
3443 
3444 static void
3445 vtnet_init_locked(struct vtnet_softc *sc, int init_mode)
3446 {
3447 	if_t ifp;
3448 
3449 	ifp = sc->vtnet_ifp;
3450 
3451 	VTNET_CORE_LOCK_ASSERT(sc);
3452 
3453 	if (if_getdrvflags(ifp) & IFF_DRV_RUNNING)
3454 		return;
3455 
3456 	vtnet_stop(sc);
3457 
3458 #ifdef DEV_NETMAP
3459 	/* Once stopped we can update the netmap flags, if necessary. */
3460 	switch (init_mode) {
3461 	case VTNET_INIT_NETMAP_ENTER:
3462 		nm_set_native_flags(NA(ifp));
3463 		break;
3464 	case VTNET_INIT_NETMAP_EXIT:
3465 		nm_clear_native_flags(NA(ifp));
3466 		break;
3467 	}
3468 #endif /* DEV_NETMAP */
3469 
3470 	if (vtnet_reinit(sc) != 0) {
3471 		vtnet_stop(sc);
3472 		return;
3473 	}
3474 
3475 	if_setdrvflagbits(ifp, IFF_DRV_RUNNING, 0);
3476 	vtnet_update_link_status(sc);
3477 	vtnet_enable_interrupts(sc);
3478 	callout_reset(&sc->vtnet_tick_ch, hz, vtnet_tick, sc);
3479 
3480 #ifdef DEV_NETMAP
3481 	/* Re-enable txsync/rxsync. */
3482 	netmap_enable_all_rings(ifp);
3483 #endif /* DEV_NETMAP */
3484 }
3485 
3486 static void
3487 vtnet_init(void *xsc)
3488 {
3489 	struct vtnet_softc *sc;
3490 
3491 	sc = xsc;
3492 
3493 	VTNET_CORE_LOCK(sc);
3494 	vtnet_init_locked(sc, 0);
3495 	VTNET_CORE_UNLOCK(sc);
3496 }
3497 
3498 static void
3499 vtnet_free_ctrl_vq(struct vtnet_softc *sc)
3500 {
3501 
3502 	/*
3503 	 * The control virtqueue is only polled and therefore it should
3504 	 * already be empty.
3505 	 */
3506 	KASSERT(virtqueue_empty(sc->vtnet_ctrl_vq),
3507 	    ("%s: ctrl vq %p not empty", __func__, sc->vtnet_ctrl_vq));
3508 }
3509 
3510 static void
3511 vtnet_exec_ctrl_cmd(struct vtnet_softc *sc, void *cookie,
3512     struct sglist *sg, int readable, int writable)
3513 {
3514 	struct virtqueue *vq;
3515 
3516 	vq = sc->vtnet_ctrl_vq;
3517 
3518 	MPASS(sc->vtnet_flags & VTNET_FLAG_CTRL_VQ);
3519 	VTNET_CORE_LOCK_ASSERT(sc);
3520 
3521 	if (!virtqueue_empty(vq))
3522 		return;
3523 
3524 	/*
3525 	 * Poll for the response, but the command is likely completed before
3526 	 * returning from the notify.
3527 	 */
3528 	if (virtqueue_enqueue(vq, cookie, sg, readable, writable) == 0)  {
3529 		virtqueue_notify(vq);
3530 		virtqueue_poll(vq, NULL);
3531 	}
3532 }
3533 
3534 static int
3535 vtnet_ctrl_mac_cmd(struct vtnet_softc *sc, uint8_t *hwaddr)
3536 {
3537 	struct sglist_seg segs[3];
3538 	struct sglist sg;
3539 	struct {
3540 		struct virtio_net_ctrl_hdr hdr __aligned(2);
3541 		uint8_t pad1;
3542 		uint8_t addr[ETHER_ADDR_LEN] __aligned(8);
3543 		uint8_t pad2;
3544 		uint8_t ack;
3545 	} s;
3546 	int error;
3547 
3548 	error = 0;
3549 	MPASS(sc->vtnet_flags & VTNET_FLAG_CTRL_MAC);
3550 
3551 	s.hdr.class = VIRTIO_NET_CTRL_MAC;
3552 	s.hdr.cmd = VIRTIO_NET_CTRL_MAC_ADDR_SET;
3553 	bcopy(hwaddr, &s.addr[0], ETHER_ADDR_LEN);
3554 	s.ack = VIRTIO_NET_ERR;
3555 
3556 	sglist_init(&sg, nitems(segs), segs);
3557 	error |= sglist_append(&sg, &s.hdr, sizeof(struct virtio_net_ctrl_hdr));
3558 	error |= sglist_append(&sg, &s.addr[0], ETHER_ADDR_LEN);
3559 	error |= sglist_append(&sg, &s.ack, sizeof(uint8_t));
3560 	MPASS(error == 0 && sg.sg_nseg == nitems(segs));
3561 
3562 	if (error == 0)
3563 		vtnet_exec_ctrl_cmd(sc, &s.ack, &sg, sg.sg_nseg - 1, 1);
3564 
3565 	return (s.ack == VIRTIO_NET_OK ? 0 : EIO);
3566 }
3567 
3568 static int
3569 vtnet_ctrl_guest_offloads(struct vtnet_softc *sc, uint64_t offloads)
3570 {
3571 	struct sglist_seg segs[3];
3572 	struct sglist sg;
3573 	struct {
3574 		struct virtio_net_ctrl_hdr hdr __aligned(2);
3575 		uint8_t pad1;
3576 		uint64_t offloads __aligned(8);
3577 		uint8_t pad2;
3578 		uint8_t ack;
3579 	} s;
3580 	int error;
3581 
3582 	error = 0;
3583 	MPASS(sc->vtnet_features & VIRTIO_NET_F_CTRL_GUEST_OFFLOADS);
3584 
3585 	s.hdr.class = VIRTIO_NET_CTRL_GUEST_OFFLOADS;
3586 	s.hdr.cmd = VIRTIO_NET_CTRL_GUEST_OFFLOADS_SET;
3587 	s.offloads = vtnet_gtoh64(sc, offloads);
3588 	s.ack = VIRTIO_NET_ERR;
3589 
3590 	sglist_init(&sg, nitems(segs), segs);
3591 	error |= sglist_append(&sg, &s.hdr, sizeof(struct virtio_net_ctrl_hdr));
3592 	error |= sglist_append(&sg, &s.offloads, sizeof(uint64_t));
3593 	error |= sglist_append(&sg, &s.ack, sizeof(uint8_t));
3594 	MPASS(error == 0 && sg.sg_nseg == nitems(segs));
3595 
3596 	if (error == 0)
3597 		vtnet_exec_ctrl_cmd(sc, &s.ack, &sg, sg.sg_nseg - 1, 1);
3598 
3599 	return (s.ack == VIRTIO_NET_OK ? 0 : EIO);
3600 }
3601 
3602 static int
3603 vtnet_ctrl_mq_cmd(struct vtnet_softc *sc, uint16_t npairs)
3604 {
3605 	struct sglist_seg segs[3];
3606 	struct sglist sg;
3607 	struct {
3608 		struct virtio_net_ctrl_hdr hdr __aligned(2);
3609 		uint8_t pad1;
3610 		struct virtio_net_ctrl_mq mq __aligned(2);
3611 		uint8_t pad2;
3612 		uint8_t ack;
3613 	} s;
3614 	int error;
3615 
3616 	error = 0;
3617 	MPASS(sc->vtnet_flags & VTNET_FLAG_MQ);
3618 
3619 	s.hdr.class = VIRTIO_NET_CTRL_MQ;
3620 	s.hdr.cmd = VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET;
3621 	s.mq.virtqueue_pairs = vtnet_gtoh16(sc, npairs);
3622 	s.ack = VIRTIO_NET_ERR;
3623 
3624 	sglist_init(&sg, nitems(segs), segs);
3625 	error |= sglist_append(&sg, &s.hdr, sizeof(struct virtio_net_ctrl_hdr));
3626 	error |= sglist_append(&sg, &s.mq, sizeof(struct virtio_net_ctrl_mq));
3627 	error |= sglist_append(&sg, &s.ack, sizeof(uint8_t));
3628 	MPASS(error == 0 && sg.sg_nseg == nitems(segs));
3629 
3630 	if (error == 0)
3631 		vtnet_exec_ctrl_cmd(sc, &s.ack, &sg, sg.sg_nseg - 1, 1);
3632 
3633 	return (s.ack == VIRTIO_NET_OK ? 0 : EIO);
3634 }
3635 
3636 static int
3637 vtnet_ctrl_rx_cmd(struct vtnet_softc *sc, uint8_t cmd, bool on)
3638 {
3639 	struct sglist_seg segs[3];
3640 	struct sglist sg;
3641 	struct {
3642 		struct virtio_net_ctrl_hdr hdr __aligned(2);
3643 		uint8_t pad1;
3644 		uint8_t onoff;
3645 		uint8_t pad2;
3646 		uint8_t ack;
3647 	} s;
3648 	int error;
3649 
3650 	error = 0;
3651 	MPASS(sc->vtnet_flags & VTNET_FLAG_CTRL_RX);
3652 
3653 	s.hdr.class = VIRTIO_NET_CTRL_RX;
3654 	s.hdr.cmd = cmd;
3655 	s.onoff = on;
3656 	s.ack = VIRTIO_NET_ERR;
3657 
3658 	sglist_init(&sg, nitems(segs), segs);
3659 	error |= sglist_append(&sg, &s.hdr, sizeof(struct virtio_net_ctrl_hdr));
3660 	error |= sglist_append(&sg, &s.onoff, sizeof(uint8_t));
3661 	error |= sglist_append(&sg, &s.ack, sizeof(uint8_t));
3662 	MPASS(error == 0 && sg.sg_nseg == nitems(segs));
3663 
3664 	if (error == 0)
3665 		vtnet_exec_ctrl_cmd(sc, &s.ack, &sg, sg.sg_nseg - 1, 1);
3666 
3667 	return (s.ack == VIRTIO_NET_OK ? 0 : EIO);
3668 }
3669 
3670 static int
3671 vtnet_set_promisc(struct vtnet_softc *sc, bool on)
3672 {
3673 	return (vtnet_ctrl_rx_cmd(sc, VIRTIO_NET_CTRL_RX_PROMISC, on));
3674 }
3675 
3676 static int
3677 vtnet_set_allmulti(struct vtnet_softc *sc, bool on)
3678 {
3679 	return (vtnet_ctrl_rx_cmd(sc, VIRTIO_NET_CTRL_RX_ALLMULTI, on));
3680 }
3681 
3682 static void
3683 vtnet_rx_filter(struct vtnet_softc *sc)
3684 {
3685 	device_t dev;
3686 	if_t ifp;
3687 
3688 	dev = sc->vtnet_dev;
3689 	ifp = sc->vtnet_ifp;
3690 
3691 	VTNET_CORE_LOCK_ASSERT(sc);
3692 
3693 	if (vtnet_set_promisc(sc, if_getflags(ifp) & IFF_PROMISC) != 0) {
3694 		device_printf(dev, "cannot %s promiscuous mode\n",
3695 		    if_getflags(ifp) & IFF_PROMISC ? "enable" : "disable");
3696 	}
3697 
3698 	if (vtnet_set_allmulti(sc, if_getflags(ifp) & IFF_ALLMULTI) != 0) {
3699 		device_printf(dev, "cannot %s all-multicast mode\n",
3700 		    if_getflags(ifp) & IFF_ALLMULTI ? "enable" : "disable");
3701 	}
3702 }
3703 
3704 static u_int
3705 vtnet_copy_ifaddr(void *arg, struct sockaddr_dl *sdl, u_int ucnt)
3706 {
3707 	struct vtnet_softc *sc = arg;
3708 
3709 	if (memcmp(LLADDR(sdl), sc->vtnet_hwaddr, ETHER_ADDR_LEN) == 0)
3710 		return (0);
3711 
3712 	if (ucnt < VTNET_MAX_MAC_ENTRIES)
3713 		bcopy(LLADDR(sdl),
3714 		    &sc->vtnet_mac_filter->vmf_unicast.macs[ucnt],
3715 		    ETHER_ADDR_LEN);
3716 
3717 	return (1);
3718 }
3719 
3720 static u_int
3721 vtnet_copy_maddr(void *arg, struct sockaddr_dl *sdl, u_int mcnt)
3722 {
3723 	struct vtnet_mac_filter *filter = arg;
3724 
3725 	if (mcnt < VTNET_MAX_MAC_ENTRIES)
3726 		bcopy(LLADDR(sdl), &filter->vmf_multicast.macs[mcnt],
3727 		    ETHER_ADDR_LEN);
3728 
3729 	return (1);
3730 }
3731 
3732 static void
3733 vtnet_rx_filter_mac(struct vtnet_softc *sc)
3734 {
3735 	struct virtio_net_ctrl_hdr hdr __aligned(2);
3736 	struct vtnet_mac_filter *filter;
3737 	struct sglist_seg segs[4];
3738 	struct sglist sg;
3739 	if_t ifp;
3740 	bool promisc, allmulti;
3741 	u_int ucnt, mcnt;
3742 	int error;
3743 	uint8_t ack;
3744 
3745 	ifp = sc->vtnet_ifp;
3746 	filter = sc->vtnet_mac_filter;
3747 	error = 0;
3748 
3749 	MPASS(sc->vtnet_flags & VTNET_FLAG_CTRL_RX);
3750 	VTNET_CORE_LOCK_ASSERT(sc);
3751 
3752 	/* Unicast MAC addresses: */
3753 	ucnt = if_foreach_lladdr(ifp, vtnet_copy_ifaddr, sc);
3754 	promisc = (ucnt > VTNET_MAX_MAC_ENTRIES);
3755 
3756 	if (promisc) {
3757 		ucnt = 0;
3758 		if_printf(ifp, "more than %d MAC addresses assigned, "
3759 		    "falling back to promiscuous mode\n",
3760 		    VTNET_MAX_MAC_ENTRIES);
3761 	}
3762 
3763 	/* Multicast MAC addresses: */
3764 	mcnt = if_foreach_llmaddr(ifp, vtnet_copy_maddr, filter);
3765 	allmulti = (mcnt > VTNET_MAX_MAC_ENTRIES);
3766 
3767 	if (allmulti) {
3768 		mcnt = 0;
3769 		if_printf(ifp, "more than %d multicast MAC addresses "
3770 		    "assigned, falling back to all-multicast mode\n",
3771 		    VTNET_MAX_MAC_ENTRIES);
3772 	}
3773 
3774 	if (promisc && allmulti)
3775 		goto out;
3776 
3777 	filter->vmf_unicast.nentries = vtnet_gtoh32(sc, ucnt);
3778 	filter->vmf_multicast.nentries = vtnet_gtoh32(sc, mcnt);
3779 
3780 	hdr.class = VIRTIO_NET_CTRL_MAC;
3781 	hdr.cmd = VIRTIO_NET_CTRL_MAC_TABLE_SET;
3782 	ack = VIRTIO_NET_ERR;
3783 
3784 	sglist_init(&sg, nitems(segs), segs);
3785 	error |= sglist_append(&sg, &hdr, sizeof(struct virtio_net_ctrl_hdr));
3786 	error |= sglist_append(&sg, &filter->vmf_unicast,
3787 	    sizeof(uint32_t) + ucnt * ETHER_ADDR_LEN);
3788 	error |= sglist_append(&sg, &filter->vmf_multicast,
3789 	    sizeof(uint32_t) + mcnt * ETHER_ADDR_LEN);
3790 	error |= sglist_append(&sg, &ack, sizeof(uint8_t));
3791 	MPASS(error == 0 && sg.sg_nseg == nitems(segs));
3792 
3793 	if (error == 0)
3794 		vtnet_exec_ctrl_cmd(sc, &ack, &sg, sg.sg_nseg - 1, 1);
3795 	if (ack != VIRTIO_NET_OK)
3796 		if_printf(ifp, "error setting host MAC filter table\n");
3797 
3798 out:
3799 	if (promisc != 0 && vtnet_set_promisc(sc, true) != 0)
3800 		if_printf(ifp, "cannot enable promiscuous mode\n");
3801 	if (allmulti != 0 && vtnet_set_allmulti(sc, true) != 0)
3802 		if_printf(ifp, "cannot enable all-multicast mode\n");
3803 }
3804 
3805 static int
3806 vtnet_exec_vlan_filter(struct vtnet_softc *sc, int add, uint16_t tag)
3807 {
3808 	struct sglist_seg segs[3];
3809 	struct sglist sg;
3810 	struct {
3811 		struct virtio_net_ctrl_hdr hdr __aligned(2);
3812 		uint8_t pad1;
3813 		uint16_t tag __aligned(2);
3814 		uint8_t pad2;
3815 		uint8_t ack;
3816 	} s;
3817 	int error;
3818 
3819 	error = 0;
3820 	MPASS(sc->vtnet_flags & VTNET_FLAG_VLAN_FILTER);
3821 
3822 	s.hdr.class = VIRTIO_NET_CTRL_VLAN;
3823 	s.hdr.cmd = add ? VIRTIO_NET_CTRL_VLAN_ADD : VIRTIO_NET_CTRL_VLAN_DEL;
3824 	s.tag = vtnet_gtoh16(sc, tag);
3825 	s.ack = VIRTIO_NET_ERR;
3826 
3827 	sglist_init(&sg, nitems(segs), segs);
3828 	error |= sglist_append(&sg, &s.hdr, sizeof(struct virtio_net_ctrl_hdr));
3829 	error |= sglist_append(&sg, &s.tag, sizeof(uint16_t));
3830 	error |= sglist_append(&sg, &s.ack, sizeof(uint8_t));
3831 	MPASS(error == 0 && sg.sg_nseg == nitems(segs));
3832 
3833 	if (error == 0)
3834 		vtnet_exec_ctrl_cmd(sc, &s.ack, &sg, sg.sg_nseg - 1, 1);
3835 
3836 	return (s.ack == VIRTIO_NET_OK ? 0 : EIO);
3837 }
3838 
3839 static void
3840 vtnet_rx_filter_vlan(struct vtnet_softc *sc)
3841 {
3842 	int i, bit;
3843 	uint32_t w;
3844 	uint16_t tag;
3845 
3846 	MPASS(sc->vtnet_flags & VTNET_FLAG_VLAN_FILTER);
3847 	VTNET_CORE_LOCK_ASSERT(sc);
3848 
3849 	/* Enable the filter for each configured VLAN. */
3850 	for (i = 0; i < VTNET_VLAN_FILTER_NWORDS; i++) {
3851 		w = sc->vtnet_vlan_filter[i];
3852 
3853 		while ((bit = ffs(w) - 1) != -1) {
3854 			w &= ~(1 << bit);
3855 			tag = sizeof(w) * CHAR_BIT * i + bit;
3856 
3857 			if (vtnet_exec_vlan_filter(sc, 1, tag) != 0) {
3858 				device_printf(sc->vtnet_dev,
3859 				    "cannot enable VLAN %d filter\n", tag);
3860 			}
3861 		}
3862 	}
3863 }
3864 
3865 static void
3866 vtnet_update_vlan_filter(struct vtnet_softc *sc, int add, uint16_t tag)
3867 {
3868 	if_t ifp;
3869 	int idx, bit;
3870 
3871 	ifp = sc->vtnet_ifp;
3872 	idx = (tag >> 5) & 0x7F;
3873 	bit = tag & 0x1F;
3874 
3875 	if (tag == 0 || tag > 4095)
3876 		return;
3877 
3878 	VTNET_CORE_LOCK(sc);
3879 
3880 	if (add)
3881 		sc->vtnet_vlan_filter[idx] |= (1 << bit);
3882 	else
3883 		sc->vtnet_vlan_filter[idx] &= ~(1 << bit);
3884 
3885 	if (if_getcapenable(ifp) & IFCAP_VLAN_HWFILTER &&
3886 	    if_getdrvflags(ifp) & IFF_DRV_RUNNING &&
3887 	    vtnet_exec_vlan_filter(sc, add, tag) != 0) {
3888 		device_printf(sc->vtnet_dev,
3889 		    "cannot %s VLAN %d %s the host filter table\n",
3890 		    add ? "add" : "remove", tag, add ? "to" : "from");
3891 	}
3892 
3893 	VTNET_CORE_UNLOCK(sc);
3894 }
3895 
3896 static void
3897 vtnet_register_vlan(void *arg, if_t ifp, uint16_t tag)
3898 {
3899 
3900 	if (if_getsoftc(ifp) != arg)
3901 		return;
3902 
3903 	vtnet_update_vlan_filter(arg, 1, tag);
3904 }
3905 
3906 static void
3907 vtnet_unregister_vlan(void *arg, if_t ifp, uint16_t tag)
3908 {
3909 
3910 	if (if_getsoftc(ifp) != arg)
3911 		return;
3912 
3913 	vtnet_update_vlan_filter(arg, 0, tag);
3914 }
3915 
3916 static void
3917 vtnet_update_speed_duplex(struct vtnet_softc *sc)
3918 {
3919 	if_t ifp;
3920 	uint32_t speed;
3921 
3922 	ifp = sc->vtnet_ifp;
3923 
3924 	if ((sc->vtnet_features & VIRTIO_NET_F_SPEED_DUPLEX) == 0)
3925 		return;
3926 
3927 	/* BMV: Ignore duplex. */
3928 	speed = virtio_read_dev_config_4(sc->vtnet_dev,
3929 	    offsetof(struct virtio_net_config, speed));
3930 	if (speed != UINT32_MAX)
3931 		if_setbaudrate(ifp, IF_Mbps(speed));
3932 }
3933 
3934 static int
3935 vtnet_is_link_up(struct vtnet_softc *sc)
3936 {
3937 	uint16_t status;
3938 
3939 	if ((sc->vtnet_features & VIRTIO_NET_F_STATUS) == 0)
3940 		return (1);
3941 
3942 	status = virtio_read_dev_config_2(sc->vtnet_dev,
3943 	    offsetof(struct virtio_net_config, status));
3944 
3945 	return ((status & VIRTIO_NET_S_LINK_UP) != 0);
3946 }
3947 
3948 static void
3949 vtnet_update_link_status(struct vtnet_softc *sc)
3950 {
3951 	if_t ifp;
3952 	int link;
3953 
3954 	ifp = sc->vtnet_ifp;
3955 	VTNET_CORE_LOCK_ASSERT(sc);
3956 	link = vtnet_is_link_up(sc);
3957 
3958 	/* Notify if the link status has changed. */
3959 	if (link != 0 && sc->vtnet_link_active == 0) {
3960 		vtnet_update_speed_duplex(sc);
3961 		sc->vtnet_link_active = 1;
3962 		if_link_state_change(ifp, LINK_STATE_UP);
3963 	} else if (link == 0 && sc->vtnet_link_active != 0) {
3964 		sc->vtnet_link_active = 0;
3965 		if_link_state_change(ifp, LINK_STATE_DOWN);
3966 	}
3967 }
3968 
3969 static int
3970 vtnet_ifmedia_upd(if_t ifp __unused)
3971 {
3972 	return (EOPNOTSUPP);
3973 }
3974 
3975 static void
3976 vtnet_ifmedia_sts(if_t ifp, struct ifmediareq *ifmr)
3977 {
3978 	struct vtnet_softc *sc;
3979 
3980 	sc = if_getsoftc(ifp);
3981 
3982 	ifmr->ifm_status = IFM_AVALID;
3983 	ifmr->ifm_active = IFM_ETHER;
3984 
3985 	VTNET_CORE_LOCK(sc);
3986 	if (vtnet_is_link_up(sc) != 0) {
3987 		ifmr->ifm_status |= IFM_ACTIVE;
3988 		ifmr->ifm_active |= IFM_10G_T | IFM_FDX;
3989 	} else
3990 		ifmr->ifm_active |= IFM_NONE;
3991 	VTNET_CORE_UNLOCK(sc);
3992 }
3993 
3994 static void
3995 vtnet_get_macaddr(struct vtnet_softc *sc)
3996 {
3997 
3998 	if (sc->vtnet_flags & VTNET_FLAG_MAC) {
3999 		virtio_read_device_config_array(sc->vtnet_dev,
4000 		    offsetof(struct virtio_net_config, mac),
4001 		    &sc->vtnet_hwaddr[0], sizeof(uint8_t), ETHER_ADDR_LEN);
4002 	} else {
4003 		/* Generate a random locally administered unicast address. */
4004 		sc->vtnet_hwaddr[0] = 0xB2;
4005 		arc4rand(&sc->vtnet_hwaddr[1], ETHER_ADDR_LEN - 1, 0);
4006 	}
4007 }
4008 
4009 static void
4010 vtnet_set_macaddr(struct vtnet_softc *sc)
4011 {
4012 	device_t dev;
4013 	int error;
4014 
4015 	dev = sc->vtnet_dev;
4016 
4017 	if (sc->vtnet_flags & VTNET_FLAG_CTRL_MAC) {
4018 		error = vtnet_ctrl_mac_cmd(sc, sc->vtnet_hwaddr);
4019 		if (error)
4020 			device_printf(dev, "unable to set MAC address\n");
4021 		return;
4022 	}
4023 
4024 	/* MAC in config is read-only in modern VirtIO. */
4025 	if (!vtnet_modern(sc) && sc->vtnet_flags & VTNET_FLAG_MAC) {
4026 		for (int i = 0; i < ETHER_ADDR_LEN; i++) {
4027 			virtio_write_dev_config_1(dev,
4028 			    offsetof(struct virtio_net_config, mac) + i,
4029 			    sc->vtnet_hwaddr[i]);
4030 		}
4031 	}
4032 }
4033 
4034 static void
4035 vtnet_attached_set_macaddr(struct vtnet_softc *sc)
4036 {
4037 
4038 	/* Assign MAC address if it was generated. */
4039 	if ((sc->vtnet_flags & VTNET_FLAG_MAC) == 0)
4040 		vtnet_set_macaddr(sc);
4041 }
4042 
4043 static void
4044 vtnet_vlan_tag_remove(struct mbuf *m)
4045 {
4046 	struct ether_vlan_header *evh;
4047 
4048 	evh = mtod(m, struct ether_vlan_header *);
4049 	m->m_pkthdr.ether_vtag = ntohs(evh->evl_tag);
4050 	m->m_flags |= M_VLANTAG;
4051 
4052 	/* Strip the 802.1Q header. */
4053 	bcopy((char *) evh, (char *) evh + ETHER_VLAN_ENCAP_LEN,
4054 	    ETHER_HDR_LEN - ETHER_TYPE_LEN);
4055 	m_adj(m, ETHER_VLAN_ENCAP_LEN);
4056 }
4057 
4058 static void
4059 vtnet_set_rx_process_limit(struct vtnet_softc *sc)
4060 {
4061 	int limit;
4062 
4063 	limit = vtnet_tunable_int(sc, "rx_process_limit",
4064 	    vtnet_rx_process_limit);
4065 	if (limit < 0)
4066 		limit = INT_MAX;
4067 	sc->vtnet_rx_process_limit = limit;
4068 }
4069 
4070 static void
4071 vtnet_setup_rxq_sysctl(struct sysctl_ctx_list *ctx,
4072     struct sysctl_oid_list *child, struct vtnet_rxq *rxq)
4073 {
4074 	struct sysctl_oid *node;
4075 	struct sysctl_oid_list *list;
4076 	struct vtnet_rxq_stats *stats;
4077 	char namebuf[16];
4078 
4079 	snprintf(namebuf, sizeof(namebuf), "rxq%d", rxq->vtnrx_id);
4080 	node = SYSCTL_ADD_NODE(ctx, child, OID_AUTO, namebuf,
4081 	    CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "Receive Queue");
4082 	list = SYSCTL_CHILDREN(node);
4083 
4084 	stats = &rxq->vtnrx_stats;
4085 
4086 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "ipackets", CTLFLAG_RD,
4087 	    &stats->vrxs_ipackets, "Receive packets");
4088 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "ibytes", CTLFLAG_RD,
4089 	    &stats->vrxs_ibytes, "Receive bytes");
4090 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "iqdrops", CTLFLAG_RD,
4091 	    &stats->vrxs_iqdrops, "Receive drops");
4092 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "ierrors", CTLFLAG_RD,
4093 	    &stats->vrxs_ierrors, "Receive errors");
4094 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "csum", CTLFLAG_RD,
4095 	    &stats->vrxs_csum, "Receive checksum offloaded");
4096 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "csum_failed", CTLFLAG_RD,
4097 	    &stats->vrxs_csum_failed, "Receive checksum offload failed");
4098 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "host_lro", CTLFLAG_RD,
4099 	    &stats->vrxs_host_lro, "Receive host segmentation offloaded");
4100 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "rescheduled", CTLFLAG_RD,
4101 	    &stats->vrxs_rescheduled,
4102 	    "Receive interrupt handler rescheduled");
4103 }
4104 
4105 static void
4106 vtnet_setup_txq_sysctl(struct sysctl_ctx_list *ctx,
4107     struct sysctl_oid_list *child, struct vtnet_txq *txq)
4108 {
4109 	struct sysctl_oid *node;
4110 	struct sysctl_oid_list *list;
4111 	struct vtnet_txq_stats *stats;
4112 	char namebuf[16];
4113 
4114 	snprintf(namebuf, sizeof(namebuf), "txq%d", txq->vtntx_id);
4115 	node = SYSCTL_ADD_NODE(ctx, child, OID_AUTO, namebuf,
4116 	    CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "Transmit Queue");
4117 	list = SYSCTL_CHILDREN(node);
4118 
4119 	stats = &txq->vtntx_stats;
4120 
4121 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "opackets", CTLFLAG_RD,
4122 	    &stats->vtxs_opackets, "Transmit packets");
4123 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "obytes", CTLFLAG_RD,
4124 	    &stats->vtxs_obytes, "Transmit bytes");
4125 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "omcasts", CTLFLAG_RD,
4126 	    &stats->vtxs_omcasts, "Transmit multicasts");
4127 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "csum", CTLFLAG_RD,
4128 	    &stats->vtxs_csum, "Transmit checksum offloaded");
4129 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "tso", CTLFLAG_RD,
4130 	    &stats->vtxs_tso, "Transmit TCP segmentation offloaded");
4131 	SYSCTL_ADD_UQUAD(ctx, list, OID_AUTO, "rescheduled", CTLFLAG_RD,
4132 	    &stats->vtxs_rescheduled,
4133 	    "Transmit interrupt handler rescheduled");
4134 }
4135 
4136 static void
4137 vtnet_setup_queue_sysctl(struct vtnet_softc *sc)
4138 {
4139 	device_t dev;
4140 	struct sysctl_ctx_list *ctx;
4141 	struct sysctl_oid *tree;
4142 	struct sysctl_oid_list *child;
4143 	int i;
4144 
4145 	dev = sc->vtnet_dev;
4146 	ctx = device_get_sysctl_ctx(dev);
4147 	tree = device_get_sysctl_tree(dev);
4148 	child = SYSCTL_CHILDREN(tree);
4149 
4150 	for (i = 0; i < sc->vtnet_req_vq_pairs; i++) {
4151 		vtnet_setup_rxq_sysctl(ctx, child, &sc->vtnet_rxqs[i]);
4152 		vtnet_setup_txq_sysctl(ctx, child, &sc->vtnet_txqs[i]);
4153 	}
4154 }
4155 
4156 static void
4157 vtnet_setup_stat_sysctl(struct sysctl_ctx_list *ctx,
4158     struct sysctl_oid_list *child, struct vtnet_softc *sc)
4159 {
4160 	struct vtnet_statistics *stats;
4161 	struct vtnet_rxq_stats rxaccum;
4162 	struct vtnet_txq_stats txaccum;
4163 
4164 	vtnet_accum_stats(sc, &rxaccum, &txaccum);
4165 
4166 	stats = &sc->vtnet_stats;
4167 	stats->rx_csum_offloaded = rxaccum.vrxs_csum;
4168 	stats->rx_csum_failed = rxaccum.vrxs_csum_failed;
4169 	stats->rx_task_rescheduled = rxaccum.vrxs_rescheduled;
4170 	stats->tx_csum_offloaded = txaccum.vtxs_csum;
4171 	stats->tx_tso_offloaded = txaccum.vtxs_tso;
4172 	stats->tx_task_rescheduled = txaccum.vtxs_rescheduled;
4173 
4174 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "mbuf_alloc_failed",
4175 	    CTLFLAG_RD, &stats->mbuf_alloc_failed,
4176 	    "Mbuf cluster allocation failures");
4177 
4178 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "rx_frame_too_large",
4179 	    CTLFLAG_RD, &stats->rx_frame_too_large,
4180 	    "Received frame larger than the mbuf chain");
4181 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "rx_enq_replacement_failed",
4182 	    CTLFLAG_RD, &stats->rx_enq_replacement_failed,
4183 	    "Enqueuing the replacement receive mbuf failed");
4184 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "rx_mergeable_failed",
4185 	    CTLFLAG_RD, &stats->rx_mergeable_failed,
4186 	    "Mergeable buffers receive failures");
4187 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "rx_csum_bad_ethtype",
4188 	    CTLFLAG_RD, &stats->rx_csum_bad_ethtype,
4189 	    "Received checksum offloaded buffer with unsupported "
4190 	    "Ethernet type");
4191 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "rx_csum_bad_ipproto",
4192 	    CTLFLAG_RD, &stats->rx_csum_bad_ipproto,
4193 	    "Received checksum offloaded buffer with incorrect IP protocol");
4194 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "rx_csum_bad_offset",
4195 	    CTLFLAG_RD, &stats->rx_csum_bad_offset,
4196 	    "Received checksum offloaded buffer with incorrect offset");
4197 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "rx_csum_bad_proto",
4198 	    CTLFLAG_RD, &stats->rx_csum_bad_proto,
4199 	    "Received checksum offloaded buffer with incorrect protocol");
4200 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "rx_csum_failed",
4201 	    CTLFLAG_RD, &stats->rx_csum_failed,
4202 	    "Received buffer checksum offload failed");
4203 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "rx_csum_offloaded",
4204 	    CTLFLAG_RD, &stats->rx_csum_offloaded,
4205 	    "Received buffer checksum offload succeeded");
4206 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "rx_task_rescheduled",
4207 	    CTLFLAG_RD, &stats->rx_task_rescheduled,
4208 	    "Times the receive interrupt task rescheduled itself");
4209 
4210 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "tx_csum_unknown_ethtype",
4211 	    CTLFLAG_RD, &stats->tx_csum_unknown_ethtype,
4212 	    "Aborted transmit of checksum offloaded buffer with unknown "
4213 	    "Ethernet type");
4214 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "tx_csum_proto_mismatch",
4215 	    CTLFLAG_RD, &stats->tx_csum_proto_mismatch,
4216 	    "Aborted transmit of checksum offloaded buffer because mismatched "
4217 	    "protocols");
4218 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "tx_tso_not_tcp",
4219 	    CTLFLAG_RD, &stats->tx_tso_not_tcp,
4220 	    "Aborted transmit of TSO buffer with non TCP protocol");
4221 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "tx_tso_without_csum",
4222 	    CTLFLAG_RD, &stats->tx_tso_without_csum,
4223 	    "Aborted transmit of TSO buffer without TCP checksum offload");
4224 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "tx_defragged",
4225 	    CTLFLAG_RD, &stats->tx_defragged,
4226 	    "Transmit mbufs defragged");
4227 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "tx_defrag_failed",
4228 	    CTLFLAG_RD, &stats->tx_defrag_failed,
4229 	    "Aborted transmit of buffer because defrag failed");
4230 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "tx_csum_offloaded",
4231 	    CTLFLAG_RD, &stats->tx_csum_offloaded,
4232 	    "Offloaded checksum of transmitted buffer");
4233 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "tx_tso_offloaded",
4234 	    CTLFLAG_RD, &stats->tx_tso_offloaded,
4235 	    "Segmentation offload of transmitted buffer");
4236 	SYSCTL_ADD_UQUAD(ctx, child, OID_AUTO, "tx_task_rescheduled",
4237 	    CTLFLAG_RD, &stats->tx_task_rescheduled,
4238 	    "Times the transmit interrupt task rescheduled itself");
4239 }
4240 
4241 static void
4242 vtnet_setup_sysctl(struct vtnet_softc *sc)
4243 {
4244 	device_t dev;
4245 	struct sysctl_ctx_list *ctx;
4246 	struct sysctl_oid *tree;
4247 	struct sysctl_oid_list *child;
4248 
4249 	dev = sc->vtnet_dev;
4250 	ctx = device_get_sysctl_ctx(dev);
4251 	tree = device_get_sysctl_tree(dev);
4252 	child = SYSCTL_CHILDREN(tree);
4253 
4254 	SYSCTL_ADD_INT(ctx, child, OID_AUTO, "max_vq_pairs",
4255 	    CTLFLAG_RD, &sc->vtnet_max_vq_pairs, 0,
4256 	    "Number of maximum supported virtqueue pairs");
4257 	SYSCTL_ADD_INT(ctx, child, OID_AUTO, "req_vq_pairs",
4258 	    CTLFLAG_RD, &sc->vtnet_req_vq_pairs, 0,
4259 	    "Number of requested virtqueue pairs");
4260 	SYSCTL_ADD_INT(ctx, child, OID_AUTO, "act_vq_pairs",
4261 	    CTLFLAG_RD, &sc->vtnet_act_vq_pairs, 0,
4262 	    "Number of active virtqueue pairs");
4263 
4264 	vtnet_setup_stat_sysctl(ctx, child, sc);
4265 }
4266 
4267 static void
4268 vtnet_load_tunables(struct vtnet_softc *sc)
4269 {
4270 
4271 	sc->vtnet_lro_entry_count = vtnet_tunable_int(sc,
4272 	    "lro_entry_count", vtnet_lro_entry_count);
4273 	if (sc->vtnet_lro_entry_count < TCP_LRO_ENTRIES)
4274 		sc->vtnet_lro_entry_count = TCP_LRO_ENTRIES;
4275 
4276 	sc->vtnet_lro_mbufq_depth = vtnet_tunable_int(sc,
4277 	    "lro_mbufq_depth", vtnet_lro_mbufq_depth);
4278 }
4279 
4280 static int
4281 vtnet_rxq_enable_intr(struct vtnet_rxq *rxq)
4282 {
4283 
4284 	return (virtqueue_enable_intr(rxq->vtnrx_vq));
4285 }
4286 
4287 static void
4288 vtnet_rxq_disable_intr(struct vtnet_rxq *rxq)
4289 {
4290 
4291 	virtqueue_disable_intr(rxq->vtnrx_vq);
4292 }
4293 
4294 static int
4295 vtnet_txq_enable_intr(struct vtnet_txq *txq)
4296 {
4297 	struct virtqueue *vq;
4298 
4299 	vq = txq->vtntx_vq;
4300 
4301 	if (vtnet_txq_below_threshold(txq) != 0)
4302 		return (virtqueue_postpone_intr(vq, VQ_POSTPONE_LONG));
4303 
4304 	/*
4305 	 * The free count is above our threshold. Keep the Tx interrupt
4306 	 * disabled until the queue is fuller.
4307 	 */
4308 	return (0);
4309 }
4310 
4311 static void
4312 vtnet_txq_disable_intr(struct vtnet_txq *txq)
4313 {
4314 
4315 	virtqueue_disable_intr(txq->vtntx_vq);
4316 }
4317 
4318 static void
4319 vtnet_enable_rx_interrupts(struct vtnet_softc *sc)
4320 {
4321 	struct vtnet_rxq *rxq;
4322 	int i;
4323 
4324 	for (i = 0; i < sc->vtnet_act_vq_pairs; i++) {
4325 		rxq = &sc->vtnet_rxqs[i];
4326 		if (vtnet_rxq_enable_intr(rxq) != 0)
4327 			taskqueue_enqueue(rxq->vtnrx_tq, &rxq->vtnrx_intrtask);
4328 	}
4329 }
4330 
4331 static void
4332 vtnet_enable_tx_interrupts(struct vtnet_softc *sc)
4333 {
4334 	int i;
4335 
4336 	for (i = 0; i < sc->vtnet_act_vq_pairs; i++)
4337 		vtnet_txq_enable_intr(&sc->vtnet_txqs[i]);
4338 }
4339 
4340 static void
4341 vtnet_enable_interrupts(struct vtnet_softc *sc)
4342 {
4343 
4344 	vtnet_enable_rx_interrupts(sc);
4345 	vtnet_enable_tx_interrupts(sc);
4346 }
4347 
4348 static void
4349 vtnet_disable_rx_interrupts(struct vtnet_softc *sc)
4350 {
4351 	int i;
4352 
4353 	for (i = 0; i < sc->vtnet_max_vq_pairs; i++)
4354 		vtnet_rxq_disable_intr(&sc->vtnet_rxqs[i]);
4355 }
4356 
4357 static void
4358 vtnet_disable_tx_interrupts(struct vtnet_softc *sc)
4359 {
4360 	int i;
4361 
4362 	for (i = 0; i < sc->vtnet_max_vq_pairs; i++)
4363 		vtnet_txq_disable_intr(&sc->vtnet_txqs[i]);
4364 }
4365 
4366 static void
4367 vtnet_disable_interrupts(struct vtnet_softc *sc)
4368 {
4369 
4370 	vtnet_disable_rx_interrupts(sc);
4371 	vtnet_disable_tx_interrupts(sc);
4372 }
4373 
4374 static int
4375 vtnet_tunable_int(struct vtnet_softc *sc, const char *knob, int def)
4376 {
4377 	char path[64];
4378 
4379 	snprintf(path, sizeof(path),
4380 	    "hw.vtnet.%d.%s", device_get_unit(sc->vtnet_dev), knob);
4381 	TUNABLE_INT_FETCH(path, &def);
4382 
4383 	return (def);
4384 }
4385 
4386 #ifdef DEBUGNET
4387 static void
4388 vtnet_debugnet_init(if_t ifp, int *nrxr, int *ncl, int *clsize)
4389 {
4390 	struct vtnet_softc *sc;
4391 
4392 	sc = if_getsoftc(ifp);
4393 
4394 	VTNET_CORE_LOCK(sc);
4395 	*nrxr = sc->vtnet_req_vq_pairs;
4396 	*ncl = DEBUGNET_MAX_IN_FLIGHT;
4397 	*clsize = sc->vtnet_rx_clustersz;
4398 	VTNET_CORE_UNLOCK(sc);
4399 }
4400 
4401 static void
4402 vtnet_debugnet_event(if_t ifp __unused, enum debugnet_ev event)
4403 {
4404 	struct vtnet_softc *sc;
4405 	static bool sw_lro_enabled = false;
4406 
4407 	/*
4408 	 * Disable software LRO, since it would require entering the network
4409 	 * epoch when calling vtnet_txq_eof() in vtnet_debugnet_poll().
4410 	 */
4411 	sc = if_getsoftc(ifp);
4412 	switch (event) {
4413 	case DEBUGNET_START:
4414 		sw_lro_enabled = (sc->vtnet_flags & VTNET_FLAG_SW_LRO) != 0;
4415 		if (sw_lro_enabled)
4416 			sc->vtnet_flags &= ~VTNET_FLAG_SW_LRO;
4417 		break;
4418 	case DEBUGNET_END:
4419 		if (sw_lro_enabled)
4420 			sc->vtnet_flags |= VTNET_FLAG_SW_LRO;
4421 		break;
4422 	}
4423 }
4424 
4425 static int
4426 vtnet_debugnet_transmit(if_t ifp, struct mbuf *m)
4427 {
4428 	struct vtnet_softc *sc;
4429 	struct vtnet_txq *txq;
4430 	int error;
4431 
4432 	sc = if_getsoftc(ifp);
4433 	if ((if_getdrvflags(ifp) & (IFF_DRV_RUNNING | IFF_DRV_OACTIVE)) !=
4434 	    IFF_DRV_RUNNING)
4435 		return (EBUSY);
4436 
4437 	txq = &sc->vtnet_txqs[0];
4438 	error = vtnet_txq_encap(txq, &m, M_NOWAIT | M_USE_RESERVE);
4439 	if (error == 0)
4440 		(void)vtnet_txq_notify(txq);
4441 	return (error);
4442 }
4443 
4444 static int
4445 vtnet_debugnet_poll(if_t ifp, int count)
4446 {
4447 	struct vtnet_softc *sc;
4448 	int i;
4449 
4450 	sc = if_getsoftc(ifp);
4451 	if ((if_getdrvflags(ifp) & (IFF_DRV_RUNNING | IFF_DRV_OACTIVE)) !=
4452 	    IFF_DRV_RUNNING)
4453 		return (EBUSY);
4454 
4455 	(void)vtnet_txq_eof(&sc->vtnet_txqs[0]);
4456 	for (i = 0; i < sc->vtnet_act_vq_pairs; i++)
4457 		(void)vtnet_rxq_eof(&sc->vtnet_rxqs[i]);
4458 	return (0);
4459 }
4460 #endif /* DEBUGNET */
4461