xref: /freebsd/usr.sbin/bhyve/pci_virtio_net.c (revision 4d65a7c6951cea0333f1a0c1b32c38489cdfa6c5)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2011 NetApp, Inc.
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, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY NETAPP, INC ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL NETAPP, INC OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/param.h>
30 #include <sys/linker_set.h>
31 #include <sys/select.h>
32 #include <sys/uio.h>
33 #include <sys/ioctl.h>
34 #include <machine/vmm_snapshot.h>
35 #include <net/ethernet.h>
36 #include <net/if.h> /* IFNAMSIZ */
37 
38 #include <err.h>
39 #include <errno.h>
40 #include <fcntl.h>
41 #include <stdio.h>
42 #include <stdlib.h>
43 #include <stdint.h>
44 #include <string.h>
45 #include <strings.h>
46 #include <unistd.h>
47 #include <assert.h>
48 #include <pthread.h>
49 #include <pthread_np.h>
50 
51 #include "bhyverun.h"
52 #include "config.h"
53 #include "debug.h"
54 #include "pci_emul.h"
55 #include "mevent.h"
56 #include "virtio.h"
57 #include "net_utils.h"
58 #include "net_backends.h"
59 #include "iov.h"
60 
61 #define VTNET_RINGSZ	1024
62 
63 #define VTNET_MAXSEGS	256
64 
65 #define VTNET_MAX_PKT_LEN	(65536 + 64)
66 
67 #define VTNET_MIN_MTU	ETHERMIN
68 #define VTNET_MAX_MTU	65535
69 
70 #define VTNET_S_HOSTCAPS      \
71   ( VIRTIO_NET_F_MAC | VIRTIO_NET_F_STATUS | \
72     VIRTIO_F_NOTIFY_ON_EMPTY | VIRTIO_RING_F_INDIRECT_DESC)
73 
74 /*
75  * PCI config-space "registers"
76  */
77 struct virtio_net_config {
78 	uint8_t  mac[6];
79 	uint16_t status;
80 	uint16_t max_virtqueue_pairs;
81 	uint16_t mtu;
82 } __packed;
83 
84 /*
85  * Queue definitions.
86  */
87 #define VTNET_RXQ	0
88 #define VTNET_TXQ	1
89 #define VTNET_CTLQ	2	/* NB: not yet supported */
90 
91 #define VTNET_MAXQ	3
92 
93 /*
94  * Debug printf
95  */
96 static int pci_vtnet_debug;
97 #define DPRINTF(params) if (pci_vtnet_debug) PRINTLN params
98 #define WPRINTF(params) PRINTLN params
99 
100 /*
101  * Per-device softc
102  */
103 struct pci_vtnet_softc {
104 	struct virtio_softc vsc_vs;
105 	struct vqueue_info vsc_queues[VTNET_MAXQ - 1];
106 	pthread_mutex_t vsc_mtx;
107 
108 	net_backend_t	*vsc_be;
109 
110 	bool    features_negotiated;	/* protected by rx_mtx */
111 
112 	int		resetting;	/* protected by tx_mtx */
113 
114 	uint64_t	vsc_features;	/* negotiated features */
115 
116 	pthread_mutex_t	rx_mtx;
117 	int		rx_merge;	/* merged rx bufs in use */
118 
119 	pthread_t 	tx_tid;
120 	pthread_mutex_t	tx_mtx;
121 	pthread_cond_t	tx_cond;
122 	int		tx_in_progress;
123 
124 	size_t		vhdrlen;
125 	size_t		be_vhdrlen;
126 
127 	struct virtio_net_config vsc_config;
128 	struct virtio_consts vsc_consts;
129 };
130 
131 static void pci_vtnet_reset(void *);
132 /* static void pci_vtnet_notify(void *, struct vqueue_info *); */
133 static int pci_vtnet_cfgread(void *, int, int, uint32_t *);
134 static int pci_vtnet_cfgwrite(void *, int, int, uint32_t);
135 static void pci_vtnet_neg_features(void *, uint64_t);
136 #ifdef BHYVE_SNAPSHOT
137 static void pci_vtnet_pause(void *);
138 static void pci_vtnet_resume(void *);
139 static int pci_vtnet_snapshot(void *, struct vm_snapshot_meta *);
140 #endif
141 
142 static struct virtio_consts vtnet_vi_consts = {
143 	.vc_name =	"vtnet",
144 	.vc_nvq =	VTNET_MAXQ - 1,
145 	.vc_cfgsize =	sizeof(struct virtio_net_config),
146 	.vc_reset =	pci_vtnet_reset,
147 	.vc_cfgread =	pci_vtnet_cfgread,
148 	.vc_cfgwrite =	pci_vtnet_cfgwrite,
149 	.vc_apply_features = pci_vtnet_neg_features,
150 	.vc_hv_caps =	VTNET_S_HOSTCAPS,
151 #ifdef BHYVE_SNAPSHOT
152 	.vc_pause =	pci_vtnet_pause,
153 	.vc_resume =	pci_vtnet_resume,
154 	.vc_snapshot =	pci_vtnet_snapshot,
155 #endif
156 };
157 
158 static void
pci_vtnet_reset(void * vsc)159 pci_vtnet_reset(void *vsc)
160 {
161 	struct pci_vtnet_softc *sc = vsc;
162 
163 	DPRINTF(("vtnet: device reset requested !"));
164 
165 	/* Acquire the RX lock to block RX processing. */
166 	pthread_mutex_lock(&sc->rx_mtx);
167 
168 	/*
169 	 * Make sure receive operation is disabled at least until we
170 	 * re-negotiate the features, since receive operation depends
171 	 * on the value of sc->rx_merge and the header length, which
172 	 * are both set in pci_vtnet_neg_features().
173 	 * Receive operation will be enabled again once the guest adds
174 	 * the first receive buffers and kicks us.
175 	 */
176 	sc->features_negotiated = false;
177 	netbe_rx_disable(sc->vsc_be);
178 
179 	/* Set sc->resetting and give a chance to the TX thread to stop. */
180 	pthread_mutex_lock(&sc->tx_mtx);
181 	sc->resetting = 1;
182 	while (sc->tx_in_progress) {
183 		pthread_mutex_unlock(&sc->tx_mtx);
184 		usleep(10000);
185 		pthread_mutex_lock(&sc->tx_mtx);
186 	}
187 
188 	/*
189 	 * Now reset rings, MSI-X vectors, and negotiated capabilities.
190 	 * Do that with the TX lock held, since we need to reset
191 	 * sc->resetting.
192 	 */
193 	vi_reset_dev(&sc->vsc_vs);
194 
195 	sc->resetting = 0;
196 	pthread_mutex_unlock(&sc->tx_mtx);
197 	pthread_mutex_unlock(&sc->rx_mtx);
198 }
199 
200 static __inline struct iovec *
iov_trim_hdr(struct iovec * iov,int * iovcnt,unsigned int hlen)201 iov_trim_hdr(struct iovec *iov, int *iovcnt, unsigned int hlen)
202 {
203 	struct iovec *riov;
204 
205 	if (iov[0].iov_len < hlen) {
206 		/*
207 		 * Not enough header space in the first fragment.
208 		 * That's not ok for us.
209 		 */
210 		return NULL;
211 	}
212 
213 	iov[0].iov_len -= hlen;
214 	if (iov[0].iov_len == 0) {
215 		*iovcnt -= 1;
216 		if (*iovcnt == 0) {
217 			/*
218 			 * Only space for the header. That's not
219 			 * enough for us.
220 			 */
221 			return NULL;
222 		}
223 		riov = &iov[1];
224 	} else {
225 		iov[0].iov_base = (void *)((uintptr_t)iov[0].iov_base + hlen);
226 		riov = &iov[0];
227 	}
228 
229 	return (riov);
230 }
231 
232 struct virtio_mrg_rxbuf_info {
233 	uint16_t idx;
234 	uint16_t pad;
235 	uint32_t len;
236 };
237 
238 static void
pci_vtnet_rx(struct pci_vtnet_softc * sc)239 pci_vtnet_rx(struct pci_vtnet_softc *sc)
240 {
241 	int prepend_hdr_len = sc->vhdrlen - sc->be_vhdrlen;
242 	struct virtio_mrg_rxbuf_info info[VTNET_MAXSEGS];
243 	struct iovec iov[VTNET_MAXSEGS + 1];
244 	struct vqueue_info *vq;
245 	struct vi_req req;
246 
247 	vq = &sc->vsc_queues[VTNET_RXQ];
248 
249 	/* Features must be negotiated */
250 	if (!sc->features_negotiated) {
251 		return;
252 	}
253 
254 	for (;;) {
255 		struct virtio_net_rxhdr *hdr;
256 		uint32_t riov_bytes;
257 		struct iovec *riov;
258 		uint32_t ulen;
259 		int riov_len;
260 		int n_chains;
261 		ssize_t rlen;
262 		ssize_t plen;
263 
264 		plen = netbe_peek_recvlen(sc->vsc_be);
265 		if (plen <= 0) {
266 			/*
267 			 * No more packets (plen == 0), or backend errored
268 			 * (plen < 0). Interrupt if needed and stop.
269 			 */
270 			vq_endchains(vq, /*used_all_avail=*/0);
271 			return;
272 		}
273 		plen += prepend_hdr_len;
274 
275 		/*
276 		 * Get a descriptor chain to store the next ingress
277 		 * packet. In case of mergeable rx buffers, get as
278 		 * many chains as necessary in order to make room
279 		 * for plen bytes.
280 		 */
281 		riov_bytes = 0;
282 		riov_len = 0;
283 		riov = iov;
284 		n_chains = 0;
285 		do {
286 			int n = vq_getchain(vq, riov, VTNET_MAXSEGS - riov_len,
287 			    &req);
288 			info[n_chains].idx = req.idx;
289 
290 			if (n == 0) {
291 				/*
292 				 * No rx buffers. Enable RX kicks and double
293 				 * check.
294 				 */
295 				vq_kick_enable(vq);
296 				if (!vq_has_descs(vq)) {
297 					/*
298 					 * Still no buffers. Return the unused
299 					 * chains (if any), interrupt if needed
300 					 * (including for NOTIFY_ON_EMPTY), and
301 					 * disable the backend until the next
302 					 * kick.
303 					 */
304 					vq_retchains(vq, n_chains);
305 					vq_endchains(vq, /*used_all_avail=*/1);
306 					netbe_rx_disable(sc->vsc_be);
307 					return;
308 				}
309 
310 				/* More rx buffers found, so keep going. */
311 				vq_kick_disable(vq);
312 				continue;
313 			}
314 			assert(n >= 1 && riov_len + n <= VTNET_MAXSEGS);
315 			riov_len += n;
316 			if (!sc->rx_merge) {
317 				n_chains = 1;
318 				break;
319 			}
320 			info[n_chains].len = (uint32_t)count_iov(riov, n);
321 			riov_bytes += info[n_chains].len;
322 			riov += n;
323 			n_chains++;
324 		} while (riov_bytes < plen && riov_len < VTNET_MAXSEGS);
325 
326 		riov = iov;
327 		hdr = riov[0].iov_base;
328 		if (prepend_hdr_len > 0) {
329 			/*
330 			 * The frontend uses a virtio-net header, but the
331 			 * backend does not. We need to prepend a zeroed
332 			 * header.
333 			 */
334 			riov = iov_trim_hdr(riov, &riov_len, prepend_hdr_len);
335 			if (riov == NULL) {
336 				/*
337 				 * The first collected chain is nonsensical,
338 				 * as it is not even enough to store the
339 				 * virtio-net header. Just drop it.
340 				 */
341 				vq_relchain(vq, info[0].idx, 0);
342 				vq_retchains(vq, n_chains - 1);
343 				continue;
344 			}
345 			memset(hdr, 0, prepend_hdr_len);
346 		}
347 
348 		rlen = netbe_recv(sc->vsc_be, riov, riov_len);
349 		if (rlen != plen - prepend_hdr_len) {
350 			/*
351 			 * If this happens it means there is something
352 			 * wrong with the backend (e.g., some other
353 			 * process is stealing our packets).
354 			 */
355 			WPRINTF(("netbe_recv: expected %zd bytes, "
356 				"got %zd", plen - prepend_hdr_len, rlen));
357 			vq_retchains(vq, n_chains);
358 			continue;
359 		}
360 
361 		ulen = (uint32_t)plen;
362 
363 		/*
364 		 * Publish the used buffers to the guest, reporting the
365 		 * number of bytes that we wrote.
366 		 */
367 		if (!sc->rx_merge) {
368 			vq_relchain(vq, info[0].idx, ulen);
369 		} else {
370 			uint32_t iolen;
371 			int i = 0;
372 
373 			do {
374 				iolen = info[i].len;
375 				if (iolen > ulen) {
376 					iolen = ulen;
377 				}
378 				vq_relchain_prepare(vq, info[i].idx, iolen);
379 				ulen -= iolen;
380 				i++;
381 			} while (ulen > 0);
382 
383 			hdr->vrh_bufs = i;
384 			vq_relchain_publish(vq);
385 			assert(i == n_chains);
386 		}
387 	}
388 
389 }
390 
391 /*
392  * Called when there is read activity on the backend file descriptor.
393  * Each buffer posted by the guest is assumed to be able to contain
394  * an entire ethernet frame + rx header.
395  */
396 static void
pci_vtnet_rx_callback(int fd __unused,enum ev_type type __unused,void * param)397 pci_vtnet_rx_callback(int fd __unused, enum ev_type type __unused, void *param)
398 {
399 	struct pci_vtnet_softc *sc = param;
400 
401 	pthread_mutex_lock(&sc->rx_mtx);
402 	pci_vtnet_rx(sc);
403 	pthread_mutex_unlock(&sc->rx_mtx);
404 
405 }
406 
407 /* Called on RX kick. */
408 static void
pci_vtnet_ping_rxq(void * vsc,struct vqueue_info * vq)409 pci_vtnet_ping_rxq(void *vsc, struct vqueue_info *vq)
410 {
411 	struct pci_vtnet_softc *sc = vsc;
412 
413 	/*
414 	 * A qnotify means that the rx process can now begin.
415 	 * Enable RX only if features are negotiated.
416 	 */
417 	pthread_mutex_lock(&sc->rx_mtx);
418 	if (!sc->features_negotiated) {
419 		pthread_mutex_unlock(&sc->rx_mtx);
420 		return;
421 	}
422 
423 	vq_kick_disable(vq);
424 	netbe_rx_enable(sc->vsc_be);
425 	pthread_mutex_unlock(&sc->rx_mtx);
426 }
427 
428 /* TX virtqueue processing, called by the TX thread. */
429 static void
pci_vtnet_proctx(struct pci_vtnet_softc * sc,struct vqueue_info * vq)430 pci_vtnet_proctx(struct pci_vtnet_softc *sc, struct vqueue_info *vq)
431 {
432 	struct iovec iov[VTNET_MAXSEGS + 1];
433 	struct iovec *siov = iov;
434 	struct vi_req req;
435 	ssize_t len;
436 	int n;
437 
438 	/*
439 	 * Obtain chain of descriptors. The first descriptor also
440 	 * contains the virtio-net header.
441 	 */
442 	n = vq_getchain(vq, iov, VTNET_MAXSEGS, &req);
443 	assert(n >= 1 && n <= VTNET_MAXSEGS);
444 
445 	if (sc->vhdrlen != sc->be_vhdrlen) {
446 		/*
447 		 * The frontend uses a virtio-net header, but the backend
448 		 * does not. We simply strip the header and ignore it, as
449 		 * it should be zero-filled.
450 		 */
451 		siov = iov_trim_hdr(siov, &n, sc->vhdrlen);
452 	}
453 
454 	if (siov == NULL) {
455 		/* The chain is nonsensical. Just drop it. */
456 		len = 0;
457 	} else {
458 		len = netbe_send(sc->vsc_be, siov, n);
459 		if (len < 0) {
460 			/*
461 			 * If send failed, report that 0 bytes
462 			 * were read.
463 			 */
464 			len = 0;
465 		}
466 	}
467 
468 	/*
469 	 * Return the processed chain to the guest, reporting
470 	 * the number of bytes that we read.
471 	 */
472 	vq_relchain(vq, req.idx, len);
473 }
474 
475 /* Called on TX kick. */
476 static void
pci_vtnet_ping_txq(void * vsc,struct vqueue_info * vq)477 pci_vtnet_ping_txq(void *vsc, struct vqueue_info *vq)
478 {
479 	struct pci_vtnet_softc *sc = vsc;
480 
481 	/*
482 	 * Any ring entries to process?
483 	 */
484 	if (!vq_has_descs(vq))
485 		return;
486 
487 	/* Signal the tx thread for processing */
488 	pthread_mutex_lock(&sc->tx_mtx);
489 	vq_kick_disable(vq);
490 	if (sc->tx_in_progress == 0)
491 		pthread_cond_signal(&sc->tx_cond);
492 	pthread_mutex_unlock(&sc->tx_mtx);
493 }
494 
495 /*
496  * Thread which will handle processing of TX desc
497  */
498 static void *
pci_vtnet_tx_thread(void * param)499 pci_vtnet_tx_thread(void *param)
500 {
501 	struct pci_vtnet_softc *sc = param;
502 	struct vqueue_info *vq;
503 	int error;
504 
505 	vq = &sc->vsc_queues[VTNET_TXQ];
506 
507 	/*
508 	 * Let us wait till the tx queue pointers get initialised &
509 	 * first tx signaled
510 	 */
511 	pthread_mutex_lock(&sc->tx_mtx);
512 	error = pthread_cond_wait(&sc->tx_cond, &sc->tx_mtx);
513 	assert(error == 0);
514 
515 	for (;;) {
516 		/* note - tx mutex is locked here */
517 		while (sc->resetting || !vq_has_descs(vq)) {
518 			vq_kick_enable(vq);
519 			if (!sc->resetting && vq_has_descs(vq))
520 				break;
521 
522 			sc->tx_in_progress = 0;
523 			error = pthread_cond_wait(&sc->tx_cond, &sc->tx_mtx);
524 			assert(error == 0);
525 		}
526 		vq_kick_disable(vq);
527 		sc->tx_in_progress = 1;
528 		pthread_mutex_unlock(&sc->tx_mtx);
529 
530 		do {
531 			/*
532 			 * Run through entries, placing them into
533 			 * iovecs and sending when an end-of-packet
534 			 * is found
535 			 */
536 			pci_vtnet_proctx(sc, vq);
537 		} while (vq_has_descs(vq));
538 
539 		/*
540 		 * Generate an interrupt if needed.
541 		 */
542 		vq_endchains(vq, /*used_all_avail=*/1);
543 
544 		pthread_mutex_lock(&sc->tx_mtx);
545 	}
546 }
547 
548 #ifdef notyet
549 static void
pci_vtnet_ping_ctlq(void * vsc,struct vqueue_info * vq)550 pci_vtnet_ping_ctlq(void *vsc, struct vqueue_info *vq)
551 {
552 
553 	DPRINTF(("vtnet: control qnotify!"));
554 }
555 #endif
556 
557 static int
pci_vtnet_init(struct pci_devinst * pi,nvlist_t * nvl)558 pci_vtnet_init(struct pci_devinst *pi, nvlist_t *nvl)
559 {
560 	struct pci_vtnet_softc *sc;
561 	const char *value;
562 	char tname[MAXCOMLEN + 1];
563 	unsigned long mtu = ETHERMTU;
564 	int err;
565 
566 	/*
567 	 * Allocate data structures for further virtio initializations.
568 	 * sc also contains a copy of vtnet_vi_consts, since capabilities
569 	 * change depending on the backend.
570 	 */
571 	sc = calloc(1, sizeof(struct pci_vtnet_softc));
572 
573 	sc->vsc_consts = vtnet_vi_consts;
574 	pthread_mutex_init(&sc->vsc_mtx, NULL);
575 
576 	sc->vsc_queues[VTNET_RXQ].vq_qsize = VTNET_RINGSZ;
577 	sc->vsc_queues[VTNET_RXQ].vq_notify = pci_vtnet_ping_rxq;
578 	sc->vsc_queues[VTNET_TXQ].vq_qsize = VTNET_RINGSZ;
579 	sc->vsc_queues[VTNET_TXQ].vq_notify = pci_vtnet_ping_txq;
580 #ifdef notyet
581 	sc->vsc_queues[VTNET_CTLQ].vq_qsize = VTNET_RINGSZ;
582         sc->vsc_queues[VTNET_CTLQ].vq_notify = pci_vtnet_ping_ctlq;
583 #endif
584 
585 	value = get_config_value_node(nvl, "mac");
586 	if (value != NULL) {
587 		err = net_parsemac(value, sc->vsc_config.mac);
588 		if (err) {
589 			free(sc);
590 			return (err);
591 		}
592 	} else
593 		net_genmac(pi, sc->vsc_config.mac);
594 
595 	value = get_config_value_node(nvl, "mtu");
596 	if (value != NULL) {
597 		err = net_parsemtu(value, &mtu);
598 		if (err) {
599 			free(sc);
600 			return (err);
601 		}
602 
603 		if (mtu < VTNET_MIN_MTU || mtu > VTNET_MAX_MTU) {
604 			err = EINVAL;
605 			errno = EINVAL;
606 			free(sc);
607 			return (err);
608 		}
609 		sc->vsc_consts.vc_hv_caps |= VIRTIO_NET_F_MTU;
610 	}
611 	sc->vsc_config.mtu = mtu;
612 
613 	/* Permit interfaces without a configured backend. */
614 	if (get_config_value_node(nvl, "backend") != NULL) {
615 		err = netbe_init(&sc->vsc_be, nvl, pci_vtnet_rx_callback, sc);
616 		if (err) {
617 			free(sc);
618 			return (err);
619 		}
620 	}
621 
622 	sc->vsc_consts.vc_hv_caps |= VIRTIO_NET_F_MRG_RXBUF |
623 	    netbe_get_cap(sc->vsc_be);
624 
625 	/*
626 	 * Since we do not actually support multiqueue,
627 	 * set the maximum virtqueue pairs to 1.
628 	 */
629 	sc->vsc_config.max_virtqueue_pairs = 1;
630 
631 	/* initialize config space */
632 	pci_set_cfgdata16(pi, PCIR_DEVICE, VIRTIO_DEV_NET);
633 	pci_set_cfgdata16(pi, PCIR_VENDOR, VIRTIO_VENDOR);
634 	pci_set_cfgdata8(pi, PCIR_CLASS, PCIC_NETWORK);
635 	pci_set_cfgdata16(pi, PCIR_SUBDEV_0, VIRTIO_ID_NETWORK);
636 	pci_set_cfgdata16(pi, PCIR_SUBVEND_0, VIRTIO_VENDOR);
637 
638 	/* Link is always up. */
639 	sc->vsc_config.status = 1;
640 
641 	vi_softc_linkup(&sc->vsc_vs, &sc->vsc_consts, sc, pi, sc->vsc_queues);
642 	sc->vsc_vs.vs_mtx = &sc->vsc_mtx;
643 
644 	/* use BAR 1 to map MSI-X table and PBA, if we're using MSI-X */
645 	if (vi_intr_init(&sc->vsc_vs, 1, fbsdrun_virtio_msix())) {
646 		free(sc);
647 		return (1);
648 	}
649 
650 	/* use BAR 0 to map config regs in IO space */
651 	vi_set_io_bar(&sc->vsc_vs, 0);
652 
653 	sc->resetting = 0;
654 
655 	sc->rx_merge = 0;
656 	sc->vhdrlen = sizeof(struct virtio_net_rxhdr) - 2;
657 	pthread_mutex_init(&sc->rx_mtx, NULL);
658 
659 	/*
660 	 * Initialize tx semaphore & spawn TX processing thread.
661 	 * As of now, only one thread for TX desc processing is
662 	 * spawned.
663 	 */
664 	sc->tx_in_progress = 0;
665 	pthread_mutex_init(&sc->tx_mtx, NULL);
666 	pthread_cond_init(&sc->tx_cond, NULL);
667 	pthread_create(&sc->tx_tid, NULL, pci_vtnet_tx_thread, (void *)sc);
668 	snprintf(tname, sizeof(tname), "vtnet-%d:%d tx", pi->pi_slot,
669 	    pi->pi_func);
670 	pthread_set_name_np(sc->tx_tid, tname);
671 
672 	return (0);
673 }
674 
675 static int
pci_vtnet_cfgwrite(void * vsc,int offset,int size,uint32_t value)676 pci_vtnet_cfgwrite(void *vsc, int offset, int size, uint32_t value)
677 {
678 	struct pci_vtnet_softc *sc = vsc;
679 	void *ptr;
680 
681 	if (offset < (int)sizeof(sc->vsc_config.mac)) {
682 		assert(offset + size <= (int)sizeof(sc->vsc_config.mac));
683 		/*
684 		 * The driver is allowed to change the MAC address
685 		 */
686 		ptr = &sc->vsc_config.mac[offset];
687 		memcpy(ptr, &value, size);
688 	} else {
689 		/* silently ignore other writes */
690 		DPRINTF(("vtnet: write to readonly reg %d", offset));
691 	}
692 
693 	return (0);
694 }
695 
696 static int
pci_vtnet_cfgread(void * vsc,int offset,int size,uint32_t * retval)697 pci_vtnet_cfgread(void *vsc, int offset, int size, uint32_t *retval)
698 {
699 	struct pci_vtnet_softc *sc = vsc;
700 	void *ptr;
701 
702 	ptr = (uint8_t *)&sc->vsc_config + offset;
703 	memcpy(retval, ptr, size);
704 	return (0);
705 }
706 
707 static void
pci_vtnet_neg_features(void * vsc,uint64_t negotiated_features)708 pci_vtnet_neg_features(void *vsc, uint64_t negotiated_features)
709 {
710 	struct pci_vtnet_softc *sc = vsc;
711 
712 	sc->vsc_features = negotiated_features;
713 
714 	if (negotiated_features & VIRTIO_NET_F_MRG_RXBUF) {
715 		sc->vhdrlen = sizeof(struct virtio_net_rxhdr);
716 		sc->rx_merge = 1;
717 	} else {
718 		/*
719 		 * Without mergeable rx buffers, virtio-net header is 2
720 		 * bytes shorter than sizeof(struct virtio_net_rxhdr).
721 		 */
722 		sc->vhdrlen = sizeof(struct virtio_net_rxhdr) - 2;
723 		sc->rx_merge = 0;
724 	}
725 
726 	/* Tell the backend to enable some capabilities it has advertised. */
727 	netbe_set_cap(sc->vsc_be, negotiated_features, sc->vhdrlen);
728 	sc->be_vhdrlen = netbe_get_vnet_hdr_len(sc->vsc_be);
729 	assert(sc->be_vhdrlen == 0 || sc->be_vhdrlen == sc->vhdrlen);
730 
731 	pthread_mutex_lock(&sc->rx_mtx);
732 	sc->features_negotiated = true;
733 	pthread_mutex_unlock(&sc->rx_mtx);
734 }
735 
736 #ifdef BHYVE_SNAPSHOT
737 static void
pci_vtnet_pause(void * vsc)738 pci_vtnet_pause(void *vsc)
739 {
740 	struct pci_vtnet_softc *sc = vsc;
741 
742 	DPRINTF(("vtnet: device pause requested !\n"));
743 
744 	/* Acquire the RX lock to block RX processing. */
745 	pthread_mutex_lock(&sc->rx_mtx);
746 
747 	/* Wait for the transmit thread to finish its processing. */
748 	pthread_mutex_lock(&sc->tx_mtx);
749 	while (sc->tx_in_progress) {
750 		pthread_mutex_unlock(&sc->tx_mtx);
751 		usleep(10000);
752 		pthread_mutex_lock(&sc->tx_mtx);
753 	}
754 }
755 
756 static void
pci_vtnet_resume(void * vsc)757 pci_vtnet_resume(void *vsc)
758 {
759 	struct pci_vtnet_softc *sc = vsc;
760 
761 	DPRINTF(("vtnet: device resume requested !\n"));
762 
763 	pthread_mutex_unlock(&sc->tx_mtx);
764 	/* The RX lock should have been acquired in vtnet_pause. */
765 	pthread_mutex_unlock(&sc->rx_mtx);
766 }
767 
768 static int
pci_vtnet_snapshot(void * vsc,struct vm_snapshot_meta * meta)769 pci_vtnet_snapshot(void *vsc, struct vm_snapshot_meta *meta)
770 {
771 	int ret;
772 	struct pci_vtnet_softc *sc = vsc;
773 
774 	DPRINTF(("vtnet: device snapshot requested !\n"));
775 
776 	/*
777 	 * Queues and consts should have been saved by the more generic
778 	 * vi_pci_snapshot function. We need to save only our features and
779 	 * config.
780 	 */
781 
782 	SNAPSHOT_VAR_OR_LEAVE(sc->vsc_features, meta, ret, done);
783 	SNAPSHOT_VAR_OR_LEAVE(sc->features_negotiated, meta, ret, done);
784 
785 	/* Force reapply negotiated features at restore time */
786 	if (meta->op == VM_SNAPSHOT_RESTORE &&
787 	    sc->features_negotiated) {
788 		pci_vtnet_neg_features(sc, sc->vsc_features);
789 		netbe_rx_enable(sc->vsc_be);
790 	}
791 
792 	SNAPSHOT_VAR_OR_LEAVE(sc->vsc_config, meta, ret, done);
793 	SNAPSHOT_VAR_OR_LEAVE(sc->rx_merge, meta, ret, done);
794 
795 	SNAPSHOT_VAR_OR_LEAVE(sc->vhdrlen, meta, ret, done);
796 	SNAPSHOT_VAR_OR_LEAVE(sc->be_vhdrlen, meta, ret, done);
797 
798 done:
799 	return (ret);
800 }
801 #endif
802 
803 static const struct pci_devemu pci_de_vnet = {
804 	.pe_emu = 	"virtio-net",
805 	.pe_init =	pci_vtnet_init,
806 	.pe_legacy_config = netbe_legacy_config,
807 	.pe_barwrite =	vi_pci_write,
808 	.pe_barread =	vi_pci_read,
809 #ifdef BHYVE_SNAPSHOT
810 	.pe_snapshot =	vi_pci_snapshot,
811 	.pe_pause =	vi_pci_pause,
812 	.pe_resume =	vi_pci_resume,
813 #endif
814 };
815 PCI_EMUL_SET(pci_de_vnet);
816