summaryrefslogtreecommitdiff
path: root/lib/librte_kni/rte_kni.c
blob: c9726d4f84b7a2800c31139e87001a86f5ff2c26 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
/* SPDX-License-Identifier: BSD-3-Clause
 * Copyright(c) 2010-2014 Intel Corporation
 */

#ifndef RTE_EXEC_ENV_LINUXAPP
#error "KNI is not supported"
#endif

#include <string.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/ioctl.h>

#include <rte_spinlock.h>
#include <rte_string_fns.h>
#include <rte_ethdev.h>
#include <rte_malloc.h>
#include <rte_log.h>
#include <rte_kni.h>
#include <rte_memzone.h>
#include <rte_tailq.h>
#include <rte_rwlock.h>
#include <rte_eal_memconfig.h>
#include <exec-env/rte_kni_common.h>
#include "rte_kni_fifo.h"

#define MAX_MBUF_BURST_NUM            32

/* Maximum number of ring entries */
#define KNI_FIFO_COUNT_MAX     1024
#define KNI_FIFO_SIZE          (KNI_FIFO_COUNT_MAX * sizeof(void *) + \
					sizeof(struct rte_kni_fifo))

#define KNI_REQUEST_MBUF_NUM_MAX      32

#define KNI_MEM_CHECK(cond, fail) do { if (cond) goto fail; } while (0)

#define KNI_MZ_NAME_FMT			"kni_info_%s"
#define KNI_TX_Q_MZ_NAME_FMT		"kni_tx_%s"
#define KNI_RX_Q_MZ_NAME_FMT		"kni_rx_%s"
#define KNI_ALLOC_Q_MZ_NAME_FMT		"kni_alloc_%s"
#define KNI_FREE_Q_MZ_NAME_FMT		"kni_free_%s"
#define KNI_REQ_Q_MZ_NAME_FMT		"kni_req_%s"
#define KNI_RESP_Q_MZ_NAME_FMT		"kni_resp_%s"
#define KNI_SYNC_ADDR_MZ_NAME_FMT	"kni_sync_%s"

TAILQ_HEAD(rte_kni_list, rte_tailq_entry);

static struct rte_tailq_elem rte_kni_tailq = {
	.name = "RTE_KNI",
};
EAL_REGISTER_TAILQ(rte_kni_tailq)

/**
 * KNI context
 */
struct rte_kni {
	char name[RTE_KNI_NAMESIZE];        /**< KNI interface name */
	uint16_t group_id;                  /**< Group ID of KNI devices */
	uint32_t slot_id;                   /**< KNI pool slot ID */
	struct rte_mempool *pktmbuf_pool;   /**< pkt mbuf mempool */
	unsigned mbuf_size;                 /**< mbuf size */

	const struct rte_memzone *m_tx_q;   /**< TX queue memzone */
	const struct rte_memzone *m_rx_q;   /**< RX queue memzone */
	const struct rte_memzone *m_alloc_q;/**< Alloc queue memzone */
	const struct rte_memzone *m_free_q; /**< Free queue memzone */

	struct rte_kni_fifo *tx_q;          /**< TX queue */
	struct rte_kni_fifo *rx_q;          /**< RX queue */
	struct rte_kni_fifo *alloc_q;       /**< Allocated mbufs queue */
	struct rte_kni_fifo *free_q;        /**< To be freed mbufs queue */

	const struct rte_memzone *m_req_q;  /**< Request queue memzone */
	const struct rte_memzone *m_resp_q; /**< Response queue memzone */
	const struct rte_memzone *m_sync_addr;/**< Sync addr memzone */

	/* For request & response */
	struct rte_kni_fifo *req_q;         /**< Request queue */
	struct rte_kni_fifo *resp_q;        /**< Response queue */
	void * sync_addr;                   /**< Req/Resp Mem address */

	struct rte_kni_ops ops;             /**< operations for request */
};

enum kni_ops_status {
	KNI_REQ_NO_REGISTER = 0,
	KNI_REQ_REGISTERED,
};

static void kni_free_mbufs(struct rte_kni *kni);
static void kni_allocate_mbufs(struct rte_kni *kni);

static volatile int kni_fd = -1;

/* Shall be called before any allocation happens */
int
rte_kni_init(unsigned int max_kni_ifaces __rte_unused)
{
	/* Check FD and open */
	if (kni_fd < 0) {
		kni_fd = open("/dev/" KNI_DEVICE, O_RDWR);
		if (kni_fd < 0) {
			RTE_LOG(ERR, KNI,
				"Can not open /dev/%s\n", KNI_DEVICE);
			return -1;
		}
	}

	return 0;
}

static struct rte_kni *
__rte_kni_get(const char *name)
{
	struct rte_kni *kni;
	struct rte_tailq_entry *te;
	struct rte_kni_list *kni_list;

	kni_list = RTE_TAILQ_CAST(rte_kni_tailq.head, rte_kni_list);

	TAILQ_FOREACH(te, kni_list, next) {
		kni = te->data;
		if (strncmp(name, kni->name, RTE_KNI_NAMESIZE) == 0)
			break;
	}

	if (te == NULL)
		kni = NULL;

	return kni;
}

static int
kni_reserve_mz(struct rte_kni *kni)
{
	char mz_name[RTE_MEMZONE_NAMESIZE];

	snprintf(mz_name, RTE_MEMZONE_NAMESIZE, KNI_TX_Q_MZ_NAME_FMT, kni->name);
	kni->m_tx_q = rte_memzone_reserve(mz_name, KNI_FIFO_SIZE, SOCKET_ID_ANY, 0);
	KNI_MEM_CHECK(kni->m_tx_q == NULL, tx_q_fail);

	snprintf(mz_name, RTE_MEMZONE_NAMESIZE, KNI_RX_Q_MZ_NAME_FMT, kni->name);
	kni->m_rx_q = rte_memzone_reserve(mz_name, KNI_FIFO_SIZE, SOCKET_ID_ANY, 0);
	KNI_MEM_CHECK(kni->m_rx_q == NULL, rx_q_fail);

	snprintf(mz_name, RTE_MEMZONE_NAMESIZE, KNI_ALLOC_Q_MZ_NAME_FMT, kni->name);
	kni->m_alloc_q = rte_memzone_reserve(mz_name, KNI_FIFO_SIZE, SOCKET_ID_ANY, 0);
	KNI_MEM_CHECK(kni->m_alloc_q == NULL, alloc_q_fail);

	snprintf(mz_name, RTE_MEMZONE_NAMESIZE, KNI_FREE_Q_MZ_NAME_FMT, kni->name);
	kni->m_free_q = rte_memzone_reserve(mz_name, KNI_FIFO_SIZE, SOCKET_ID_ANY, 0);
	KNI_MEM_CHECK(kni->m_free_q == NULL, free_q_fail);

	snprintf(mz_name, RTE_MEMZONE_NAMESIZE, KNI_REQ_Q_MZ_NAME_FMT, kni->name);
	kni->m_req_q = rte_memzone_reserve(mz_name, KNI_FIFO_SIZE, SOCKET_ID_ANY, 0);
	KNI_MEM_CHECK(kni->m_req_q == NULL, req_q_fail);

	snprintf(mz_name, RTE_MEMZONE_NAMESIZE, KNI_RESP_Q_MZ_NAME_FMT, kni->name);
	kni->m_resp_q = rte_memzone_reserve(mz_name, KNI_FIFO_SIZE, SOCKET_ID_ANY, 0);
	KNI_MEM_CHECK(kni->m_resp_q == NULL, resp_q_fail);

	snprintf(mz_name, RTE_MEMZONE_NAMESIZE, KNI_SYNC_ADDR_MZ_NAME_FMT, kni->name);
	kni->m_sync_addr = rte_memzone_reserve(mz_name, KNI_FIFO_SIZE, SOCKET_ID_ANY, 0);
	KNI_MEM_CHECK(kni->m_sync_addr == NULL, sync_addr_fail);

	return 0;

sync_addr_fail:
	rte_memzone_free(kni->m_resp_q);
resp_q_fail:
	rte_memzone_free(kni->m_req_q);
req_q_fail:
	rte_memzone_free(kni->m_free_q);
free_q_fail:
	rte_memzone_free(kni->m_alloc_q);
alloc_q_fail:
	rte_memzone_free(kni->m_rx_q);
rx_q_fail:
	rte_memzone_free(kni->m_tx_q);
tx_q_fail:
	return -1;
}

static void
kni_release_mz(struct rte_kni *kni)
{
	rte_memzone_free(kni->m_tx_q);
	rte_memzone_free(kni->m_rx_q);
	rte_memzone_free(kni->m_alloc_q);
	rte_memzone_free(kni->m_free_q);
	rte_memzone_free(kni->m_req_q);
	rte_memzone_free(kni->m_resp_q);
	rte_memzone_free(kni->m_sync_addr);
}

struct rte_kni *
rte_kni_alloc(struct rte_mempool *pktmbuf_pool,
	      const struct rte_kni_conf *conf,
	      struct rte_kni_ops *ops)
{
	int ret;
	struct rte_kni_device_info dev_info;
	struct rte_kni *kni;
	struct rte_tailq_entry *te;
	struct rte_kni_list *kni_list;

	if (!pktmbuf_pool || !conf || !conf->name[0])
		return NULL;

	/* Check if KNI subsystem has been initialized */
	if (kni_fd < 0) {
		RTE_LOG(ERR, KNI, "KNI subsystem has not been initialized. Invoke rte_kni_init() first\n");
		return NULL;
	}

	rte_rwlock_write_lock(RTE_EAL_TAILQ_RWLOCK);

	kni = __rte_kni_get(conf->name);
	if (kni != NULL) {
		RTE_LOG(ERR, KNI, "KNI already exists\n");
		goto unlock;
	}

	te = rte_zmalloc("KNI_TAILQ_ENTRY", sizeof(*te), 0);
	if (te == NULL) {
		RTE_LOG(ERR, KNI, "Failed to allocate tailq entry\n");
		goto unlock;
	}

	kni = rte_zmalloc("KNI", sizeof(struct rte_kni), RTE_CACHE_LINE_SIZE);
	if (kni == NULL) {
		RTE_LOG(ERR, KNI, "KNI memory allocation failed\n");
		goto kni_fail;
	}

	snprintf(kni->name, RTE_KNI_NAMESIZE, "%s", conf->name);

	if (ops)
		memcpy(&kni->ops, ops, sizeof(struct rte_kni_ops));
	else
		kni->ops.port_id = UINT16_MAX;

	memset(&dev_info, 0, sizeof(dev_info));
	dev_info.bus = conf->addr.bus;
	dev_info.devid = conf->addr.devid;
	dev_info.function = conf->addr.function;
	dev_info.vendor_id = conf->id.vendor_id;
	dev_info.device_id = conf->id.device_id;
	dev_info.core_id = conf->core_id;
	dev_info.force_bind = conf->force_bind;
	dev_info.group_id = conf->group_id;
	dev_info.mbuf_size = conf->mbuf_size;
	dev_info.mtu = conf->mtu;

	memcpy(dev_info.mac_addr, conf->mac_addr, ETHER_ADDR_LEN);

	snprintf(dev_info.name, RTE_KNI_NAMESIZE, "%s", conf->name);

	RTE_LOG(INFO, KNI, "pci: %02x:%02x:%02x \t %02x:%02x\n",
		dev_info.bus, dev_info.devid, dev_info.function,
			dev_info.vendor_id, dev_info.device_id);

	ret = kni_reserve_mz(kni);
	if (ret < 0)
		goto mz_fail;

	/* TX RING */
	kni->tx_q = kni->m_tx_q->addr;
	kni_fifo_init(kni->tx_q, KNI_FIFO_COUNT_MAX);
	dev_info.tx_phys = kni->m_tx_q->phys_addr;

	/* RX RING */
	kni->rx_q = kni->m_rx_q->addr;
	kni_fifo_init(kni->rx_q, KNI_FIFO_COUNT_MAX);
	dev_info.rx_phys = kni->m_rx_q->phys_addr;

	/* ALLOC RING */
	kni->alloc_q = kni->m_alloc_q->addr;
	kni_fifo_init(kni->alloc_q, KNI_FIFO_COUNT_MAX);
	dev_info.alloc_phys = kni->m_alloc_q->phys_addr;

	/* FREE RING */
	kni->free_q = kni->m_free_q->addr;
	kni_fifo_init(kni->free_q, KNI_FIFO_COUNT_MAX);
	dev_info.free_phys = kni->m_free_q->phys_addr;

	/* Request RING */
	kni->req_q = kni->m_req_q->addr;
	kni_fifo_init(kni->req_q, KNI_FIFO_COUNT_MAX);
	dev_info.req_phys = kni->m_req_q->phys_addr;

	/* Response RING */
	kni->resp_q = kni->m_resp_q->addr;
	kni_fifo_init(kni->resp_q, KNI_FIFO_COUNT_MAX);
	dev_info.resp_phys = kni->m_resp_q->phys_addr;

	/* Req/Resp sync mem area */
	kni->sync_addr = kni->m_sync_addr->addr;
	dev_info.sync_va = kni->m_sync_addr->addr;
	dev_info.sync_phys = kni->m_sync_addr->phys_addr;

	kni->pktmbuf_pool = pktmbuf_pool;
	kni->group_id = conf->group_id;
	kni->mbuf_size = conf->mbuf_size;

	ret = ioctl(kni_fd, RTE_KNI_IOCTL_CREATE, &dev_info);
	if (ret < 0)
		goto ioctl_fail;

	te->data = kni;

	kni_list = RTE_TAILQ_CAST(rte_kni_tailq.head, rte_kni_list);
	TAILQ_INSERT_TAIL(kni_list, te, next);

	rte_rwlock_write_unlock(RTE_EAL_TAILQ_RWLOCK);

	/* Allocate mbufs and then put them into alloc_q */
	kni_allocate_mbufs(kni);

	return kni;

ioctl_fail:
	kni_release_mz(kni);
mz_fail:
	rte_free(kni);
kni_fail:
	rte_free(te);
unlock:
	rte_rwlock_write_unlock(RTE_EAL_TAILQ_RWLOCK);

	return NULL;
}

static void
kni_free_fifo(struct rte_kni_fifo *fifo)
{
	int ret;
	struct rte_mbuf *pkt;

	do {
		ret = kni_fifo_get(fifo, (void **)&pkt, 1);
		if (ret)
			rte_pktmbuf_free(pkt);
	} while (ret);
}

static void *
va2pa(struct rte_mbuf *m)
{
	return (void *)((unsigned long)m -
			((unsigned long)m->buf_addr -
			 (unsigned long)m->buf_iova));
}

static void
obj_free(struct rte_mempool *mp __rte_unused, void *opaque, void *obj,
		unsigned obj_idx __rte_unused)
{
	struct rte_mbuf *m = obj;
	void *mbuf_phys = opaque;

	if (va2pa(m) == mbuf_phys)
		rte_pktmbuf_free(m);
}

static void
kni_free_fifo_phy(struct rte_mempool *mp, struct rte_kni_fifo *fifo)
{
	void *mbuf_phys;
	int ret;

	do {
		ret = kni_fifo_get(fifo, &mbuf_phys, 1);
		if (ret)
			rte_mempool_obj_iter(mp, obj_free, mbuf_phys);
	} while (ret);
}

int
rte_kni_release(struct rte_kni *kni)
{
	struct rte_tailq_entry *te;
	struct rte_kni_list *kni_list;
	struct rte_kni_device_info dev_info;
	uint32_t retry = 5;

	if (!kni)
		return -1;

	kni_list = RTE_TAILQ_CAST(rte_kni_tailq.head, rte_kni_list);

	rte_rwlock_write_lock(RTE_EAL_TAILQ_RWLOCK);

	TAILQ_FOREACH(te, kni_list, next) {
		if (te->data == kni)
			break;
	}

	if (te == NULL)
		goto unlock;

	snprintf(dev_info.name, sizeof(dev_info.name), "%s", kni->name);
	if (ioctl(kni_fd, RTE_KNI_IOCTL_RELEASE, &dev_info) < 0) {
		RTE_LOG(ERR, KNI, "Fail to release kni device\n");
		goto unlock;
	}

	TAILQ_REMOVE(kni_list, te, next);

	rte_rwlock_write_unlock(RTE_EAL_TAILQ_RWLOCK);

	/* mbufs in all fifo should be released, except request/response */

	/* wait until all rxq packets processed by kernel */
	while (kni_fifo_count(kni->rx_q) && retry--)
		usleep(1000);

	if (kni_fifo_count(kni->rx_q))
		RTE_LOG(ERR, KNI, "Fail to free all Rx-q items\n");

	kni_free_fifo_phy(kni->pktmbuf_pool, kni->alloc_q);
	kni_free_fifo(kni->tx_q);
	kni_free_fifo(kni->free_q);

	kni_release_mz(kni);

	rte_free(kni);

	rte_free(te);

	return 0;

unlock:
	rte_rwlock_write_unlock(RTE_EAL_TAILQ_RWLOCK);

	return -1;
}

/* default callback for request of configuring device mac address */
static int
kni_config_mac_address(uint16_t port_id, uint8_t mac_addr[])
{
	int ret = 0;

	if (!rte_eth_dev_is_valid_port(port_id)) {
		RTE_LOG(ERR, KNI, "Invalid port id %d\n", port_id);
		return -EINVAL;
	}

	RTE_LOG(INFO, KNI, "Configure mac address of %d", port_id);

	ret = rte_eth_dev_default_mac_addr_set(port_id,
					       (struct ether_addr *)mac_addr);
	if (ret < 0)
		RTE_LOG(ERR, KNI, "Failed to config mac_addr for port %d\n",
			port_id);

	return ret;
}

/* default callback for request of configuring promiscuous mode */
static int
kni_config_promiscusity(uint16_t port_id, uint8_t to_on)
{
	if (!rte_eth_dev_is_valid_port(port_id)) {
		RTE_LOG(ERR, KNI, "Invalid port id %d\n", port_id);
		return -EINVAL;
	}

	RTE_LOG(INFO, KNI, "Configure promiscuous mode of %d to %d\n",
		port_id, to_on);

	if (to_on)
		rte_eth_promiscuous_enable(port_id);
	else
		rte_eth_promiscuous_disable(port_id);

	return 0;
}

int
rte_kni_handle_request(struct rte_kni *kni)
{
	unsigned ret;
	struct rte_kni_request *req;

	if (kni == NULL)
		return -1;

	/* Get request mbuf */
	ret = kni_fifo_get(kni->req_q, (void **)&req, 1);
	if (ret != 1)
		return 0; /* It is OK of can not getting the request mbuf */

	if (req != kni->sync_addr) {
		RTE_LOG(ERR, KNI, "Wrong req pointer %p\n", req);
		return -1;
	}

	/* Analyze the request and call the relevant actions for it */
	switch (req->req_id) {
	case RTE_KNI_REQ_CHANGE_MTU: /* Change MTU */
		if (kni->ops.change_mtu)
			req->result = kni->ops.change_mtu(kni->ops.port_id,
							req->new_mtu);
		break;
	case RTE_KNI_REQ_CFG_NETWORK_IF: /* Set network interface up/down */
		if (kni->ops.config_network_if)
			req->result = kni->ops.config_network_if(\
					kni->ops.port_id, req->if_up);
		break;
	case RTE_KNI_REQ_CHANGE_MAC_ADDR: /* Change MAC Address */
		if (kni->ops.config_mac_address)
			req->result = kni->ops.config_mac_address(
					kni->ops.port_id, req->mac_addr);
		else if (kni->ops.port_id != UINT16_MAX)
			req->result = kni_config_mac_address(
					kni->ops.port_id, req->mac_addr);
		break;
	case RTE_KNI_REQ_CHANGE_PROMISC: /* Change PROMISCUOUS MODE */
		if (kni->ops.config_promiscusity)
			req->result = kni->ops.config_promiscusity(
					kni->ops.port_id, req->promiscusity);
		else if (kni->ops.port_id != UINT16_MAX)
			req->result = kni_config_promiscusity(
					kni->ops.port_id, req->promiscusity);
		break;
	default:
		RTE_LOG(ERR, KNI, "Unknown request id %u\n", req->req_id);
		req->result = -EINVAL;
		break;
	}

	/* Construct response mbuf and put it back to resp_q */
	ret = kni_fifo_put(kni->resp_q, (void **)&req, 1);
	if (ret != 1) {
		RTE_LOG(ERR, KNI, "Fail to put the muf back to resp_q\n");
		return -1; /* It is an error of can't putting the mbuf back */
	}

	return 0;
}

unsigned
rte_kni_tx_burst(struct rte_kni *kni, struct rte_mbuf **mbufs, unsigned num)
{
	void *phy_mbufs[num];
	unsigned int ret;
	unsigned int i;

	for (i = 0; i < num; i++)
		phy_mbufs[i] = va2pa(mbufs[i]);

	ret = kni_fifo_put(kni->rx_q, phy_mbufs, num);

	/* Get mbufs from free_q and then free them */
	kni_free_mbufs(kni);

	return ret;
}

unsigned
rte_kni_rx_burst(struct rte_kni *kni, struct rte_mbuf **mbufs, unsigned num)
{
	unsigned ret = kni_fifo_get(kni->tx_q, (void **)mbufs, num);

	/* If buffers removed, allocate mbufs and then put them into alloc_q */
	if (ret)
		kni_allocate_mbufs(kni);

	return ret;
}

static void
kni_free_mbufs(struct rte_kni *kni)
{
	int i, ret;
	struct rte_mbuf *pkts[MAX_MBUF_BURST_NUM];

	ret = kni_fifo_get(kni->free_q, (void **)pkts, MAX_MBUF_BURST_NUM);
	if (likely(ret > 0)) {
		for (i = 0; i < ret; i++)
			rte_pktmbuf_free(pkts[i]);
	}
}

static void
kni_allocate_mbufs(struct rte_kni *kni)
{
	int i, ret;
	struct rte_mbuf *pkts[MAX_MBUF_BURST_NUM];
	void *phys[MAX_MBUF_BURST_NUM];
	int allocq_free;

	RTE_BUILD_BUG_ON(offsetof(struct rte_mbuf, pool) !=
			 offsetof(struct rte_kni_mbuf, pool));
	RTE_BUILD_BUG_ON(offsetof(struct rte_mbuf, buf_addr) !=
			 offsetof(struct rte_kni_mbuf, buf_addr));
	RTE_BUILD_BUG_ON(offsetof(struct rte_mbuf, next) !=
			 offsetof(struct rte_kni_mbuf, next));
	RTE_BUILD_BUG_ON(offsetof(struct rte_mbuf, data_off) !=
			 offsetof(struct rte_kni_mbuf, data_off));
	RTE_BUILD_BUG_ON(offsetof(struct rte_mbuf, data_len) !=
			 offsetof(struct rte_kni_mbuf, data_len));
	RTE_BUILD_BUG_ON(offsetof(struct rte_mbuf, pkt_len) !=
			 offsetof(struct rte_kni_mbuf, pkt_len));
	RTE_BUILD_BUG_ON(offsetof(struct rte_mbuf, ol_flags) !=
			 offsetof(struct rte_kni_mbuf, ol_flags));

	/* Check if pktmbuf pool has been configured */
	if (kni->pktmbuf_pool == NULL) {
		RTE_LOG(ERR, KNI, "No valid mempool for allocating mbufs\n");
		return;
	}

	allocq_free = (kni->alloc_q->read - kni->alloc_q->write - 1) \
			& (MAX_MBUF_BURST_NUM - 1);
	for (i = 0; i < allocq_free; i++) {
		pkts[i] = rte_pktmbuf_alloc(kni->pktmbuf_pool);
		if (unlikely(pkts[i] == NULL)) {
			/* Out of memory */
			RTE_LOG(ERR, KNI, "Out of memory\n");
			break;
		}
		phys[i] = va2pa(pkts[i]);
	}

	/* No pkt mbuf allocated */
	if (i <= 0)
		return;

	ret = kni_fifo_put(kni->alloc_q, phys, i);

	/* Check if any mbufs not put into alloc_q, and then free them */
	if (ret >= 0 && ret < i && ret < MAX_MBUF_BURST_NUM) {
		int j;

		for (j = ret; j < i; j++)
			rte_pktmbuf_free(pkts[j]);
	}
}

struct rte_kni *
rte_kni_get(const char *name)
{
	struct rte_kni *kni;

	if (name == NULL || name[0] == '\0')
		return NULL;

	rte_rwlock_read_lock(RTE_EAL_TAILQ_RWLOCK);

	kni = __rte_kni_get(name);

	rte_rwlock_read_unlock(RTE_EAL_TAILQ_RWLOCK);

	return kni;
}

const char *
rte_kni_get_name(const struct rte_kni *kni)
{
	return kni->name;
}

static enum kni_ops_status
kni_check_request_register(struct rte_kni_ops *ops)
{
	/* check if KNI request ops has been registered*/
	if( NULL == ops )
		return KNI_REQ_NO_REGISTER;

	if ((ops->change_mtu == NULL)
		&& (ops->config_network_if == NULL)
		&& (ops->config_mac_address == NULL)
		&& (ops->config_promiscusity == NULL))
		return KNI_REQ_NO_REGISTER;

	return KNI_REQ_REGISTERED;
}

int
rte_kni_register_handlers(struct rte_kni *kni,struct rte_kni_ops *ops)
{
	enum kni_ops_status req_status;

	if (NULL == ops) {
		RTE_LOG(ERR, KNI, "Invalid KNI request operation.\n");
		return -1;
	}

	if (NULL == kni) {
		RTE_LOG(ERR, KNI, "Invalid kni info.\n");
		return -1;
	}

	req_status = kni_check_request_register(&kni->ops);
	if ( KNI_REQ_REGISTERED == req_status) {
		RTE_LOG(ERR, KNI, "The KNI request operation has already registered.\n");
		return -1;
	}

	memcpy(&kni->ops, ops, sizeof(struct rte_kni_ops));
	return 0;
}

int
rte_kni_unregister_handlers(struct rte_kni *kni)
{
	if (NULL == kni) {
		RTE_LOG(ERR, KNI, "Invalid kni info.\n");
		return -1;
	}

	memset(&kni->ops, 0, sizeof(struct rte_kni_ops));

	return 0;
}

int __rte_experimental
rte_kni_update_link(struct rte_kni *kni, unsigned int linkup)
{
	char path[64];
	char old_carrier[2];
	const char *new_carrier;
	int old_linkup;
	int fd, ret;

	if (kni == NULL)
		return -1;

	snprintf(path, sizeof(path), "/sys/devices/virtual/net/%s/carrier",
		kni->name);

	fd = open(path, O_RDWR);
	if (fd == -1) {
		RTE_LOG(ERR, KNI, "Failed to open file: %s.\n", path);
		return -1;
	}

	ret = read(fd, old_carrier, 2);
	if (ret < 1) {
		close(fd);
		return -1;
	}
	old_linkup = (old_carrier[0] == '1');

	new_carrier = linkup ? "1" : "0";
	ret = write(fd, new_carrier, 1);
	if (ret < 1) {
		RTE_LOG(ERR, KNI, "Failed to write file: %s.\n", path);
		close(fd);
		return -1;
	}

	close(fd);
	return old_linkup;
}

void
rte_kni_close(void)
{
	if (kni_fd < 0)
		return;

	close(kni_fd);
	kni_fd = -1;
}