summaryrefslogtreecommitdiffstats
path: root/src/spdk/lib/env_dpdk/memory.c
blob: 4c2205a463338396c80934e675bbd9214522d6f1 (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
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
/*-
 *   BSD LICENSE
 *
 *   Copyright (c) Intel Corporation.
 *   All rights reserved.
 *
 *   Redistribution and use in source and binary forms, with or without
 *   modification, are permitted provided that the following conditions
 *   are met:
 *
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in
 *       the documentation and/or other materials provided with the
 *       distribution.
 *     * Neither the name of Intel Corporation nor the names of its
 *       contributors may be used to endorse or promote products derived
 *       from this software without specific prior written permission.
 *
 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "spdk/stdinc.h"

#include "env_internal.h"

#include <rte_config.h>
#include <rte_memory.h>
#include <rte_eal_memconfig.h>

#include "spdk_internal/assert.h"

#include "spdk/assert.h"
#include "spdk/likely.h"
#include "spdk/queue.h"
#include "spdk/util.h"
#include "spdk/memory.h"
#include "spdk/env_dpdk.h"

#ifdef __FreeBSD__
#define VFIO_ENABLED 0
#else
#include <linux/version.h>
#if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 6, 0)
#define VFIO_ENABLED 1
#include <linux/vfio.h>
#include <rte_vfio.h>

struct spdk_vfio_dma_map {
	struct vfio_iommu_type1_dma_map map;
	struct vfio_iommu_type1_dma_unmap unmap;
	TAILQ_ENTRY(spdk_vfio_dma_map) tailq;
};

struct vfio_cfg {
	int fd;
	bool enabled;
	bool noiommu_enabled;
	unsigned device_ref;
	TAILQ_HEAD(, spdk_vfio_dma_map) maps;
	pthread_mutex_t mutex;
};

static struct vfio_cfg g_vfio = {
	.fd = -1,
	.enabled = false,
	.noiommu_enabled = false,
	.device_ref = 0,
	.maps = TAILQ_HEAD_INITIALIZER(g_vfio.maps),
	.mutex = PTHREAD_MUTEX_INITIALIZER
};

#else
#define VFIO_ENABLED 0
#endif
#endif

#if DEBUG
#define DEBUG_PRINT(...) fprintf(stderr, __VA_ARGS__)
#else
#define DEBUG_PRINT(...)
#endif

#define FN_2MB_TO_4KB(fn)	(fn << (SHIFT_2MB - SHIFT_4KB))
#define FN_4KB_TO_2MB(fn)	(fn >> (SHIFT_2MB - SHIFT_4KB))

#define MAP_256TB_IDX(vfn_2mb)	((vfn_2mb) >> (SHIFT_1GB - SHIFT_2MB))
#define MAP_1GB_IDX(vfn_2mb)	((vfn_2mb) & ((1ULL << (SHIFT_1GB - SHIFT_2MB)) - 1))

/* Page is registered */
#define REG_MAP_REGISTERED	(1ULL << 62)

/* A notification region barrier. The 2MB translation entry that's marked
 * with this flag must be unregistered separately. This allows contiguous
 * regions to be unregistered in the same chunks they were registered.
 */
#define REG_MAP_NOTIFY_START	(1ULL << 63)

/* Translation of a single 2MB page. */
struct map_2mb {
	uint64_t translation_2mb;
};

/* Second-level map table indexed by bits [21..29] of the virtual address.
 * Each entry contains the address translation or error for entries that haven't
 * been retrieved yet.
 */
struct map_1gb {
	struct map_2mb map[1ULL << (SHIFT_1GB - SHIFT_2MB)];
};

/* Top-level map table indexed by bits [30..47] of the virtual address.
 * Each entry points to a second-level map table or NULL.
 */
struct map_256tb {
	struct map_1gb *map[1ULL << (SHIFT_256TB - SHIFT_1GB)];
};

/* Page-granularity memory address translation */
struct spdk_mem_map {
	struct map_256tb map_256tb;
	pthread_mutex_t mutex;
	uint64_t default_translation;
	struct spdk_mem_map_ops ops;
	void *cb_ctx;
	TAILQ_ENTRY(spdk_mem_map) tailq;
};

/* Registrations map. The 64 bit translations are bit fields with the
 * following layout (starting with the low bits):
 *    0 - 61 : reserved
 *   62 - 63 : flags
 */
static struct spdk_mem_map *g_mem_reg_map;
static TAILQ_HEAD(spdk_mem_map_head, spdk_mem_map) g_spdk_mem_maps =
	TAILQ_HEAD_INITIALIZER(g_spdk_mem_maps);
static pthread_mutex_t g_spdk_mem_map_mutex = PTHREAD_MUTEX_INITIALIZER;

static bool g_legacy_mem;

/*
 * Walk the currently registered memory via the main memory registration map
 * and call the new map's notify callback for each virtually contiguous region.
 */
static int
mem_map_notify_walk(struct spdk_mem_map *map, enum spdk_mem_map_notify_action action)
{
	size_t idx_256tb;
	uint64_t idx_1gb;
	uint64_t contig_start = UINT64_MAX;
	uint64_t contig_end = UINT64_MAX;
	struct map_1gb *map_1gb;
	int rc;

	if (!g_mem_reg_map) {
		return -EINVAL;
	}

	/* Hold the memory registration map mutex so no new registrations can be added while we are looping. */
	pthread_mutex_lock(&g_mem_reg_map->mutex);

	for (idx_256tb = 0;
	     idx_256tb < sizeof(g_mem_reg_map->map_256tb.map) / sizeof(g_mem_reg_map->map_256tb.map[0]);
	     idx_256tb++) {
		map_1gb = g_mem_reg_map->map_256tb.map[idx_256tb];

		if (!map_1gb) {
			if (contig_start != UINT64_MAX) {
				/* End of of a virtually contiguous range */
				rc = map->ops.notify_cb(map->cb_ctx, map, action,
							(void *)contig_start,
							contig_end - contig_start + VALUE_2MB);
				/* Don't bother handling unregister failures. It can't be any worse */
				if (rc != 0 && action == SPDK_MEM_MAP_NOTIFY_REGISTER) {
					goto err_unregister;
				}
			}
			contig_start = UINT64_MAX;
			continue;
		}

		for (idx_1gb = 0; idx_1gb < sizeof(map_1gb->map) / sizeof(map_1gb->map[0]); idx_1gb++) {
			if ((map_1gb->map[idx_1gb].translation_2mb & REG_MAP_REGISTERED) &&
			    (contig_start == UINT64_MAX ||
			     (map_1gb->map[idx_1gb].translation_2mb & REG_MAP_NOTIFY_START) == 0)) {
				/* Rebuild the virtual address from the indexes */
				uint64_t vaddr = (idx_256tb << SHIFT_1GB) | (idx_1gb << SHIFT_2MB);

				if (contig_start == UINT64_MAX) {
					contig_start = vaddr;
				}

				contig_end = vaddr;
			} else {
				if (contig_start != UINT64_MAX) {
					/* End of of a virtually contiguous range */
					rc = map->ops.notify_cb(map->cb_ctx, map, action,
								(void *)contig_start,
								contig_end - contig_start + VALUE_2MB);
					/* Don't bother handling unregister failures. It can't be any worse */
					if (rc != 0 && action == SPDK_MEM_MAP_NOTIFY_REGISTER) {
						goto err_unregister;
					}

					/* This page might be a part of a neighbour region, so process
					 * it again. The idx_1gb will be incremented immediately.
					 */
					idx_1gb--;
				}
				contig_start = UINT64_MAX;
			}
		}
	}

	pthread_mutex_unlock(&g_mem_reg_map->mutex);
	return 0;

err_unregister:
	/* Unwind to the first empty translation so we don't unregister
	 * a region that just failed to register.
	 */
	idx_256tb = MAP_256TB_IDX((contig_start >> SHIFT_2MB) - 1);
	idx_1gb = MAP_1GB_IDX((contig_start >> SHIFT_2MB) - 1);
	contig_start = UINT64_MAX;
	contig_end = UINT64_MAX;

	/* Unregister any memory we managed to register before the failure */
	for (; idx_256tb < SIZE_MAX; idx_256tb--) {
		map_1gb = g_mem_reg_map->map_256tb.map[idx_256tb];

		if (!map_1gb) {
			if (contig_end != UINT64_MAX) {
				/* End of of a virtually contiguous range */
				map->ops.notify_cb(map->cb_ctx, map,
						   SPDK_MEM_MAP_NOTIFY_UNREGISTER,
						   (void *)contig_start,
						   contig_end - contig_start + VALUE_2MB);
			}
			contig_end = UINT64_MAX;
			continue;
		}

		for (; idx_1gb < UINT64_MAX; idx_1gb--) {
			if ((map_1gb->map[idx_1gb].translation_2mb & REG_MAP_REGISTERED) &&
			    (contig_end == UINT64_MAX || (map_1gb->map[idx_1gb].translation_2mb & REG_MAP_NOTIFY_START) == 0)) {
				/* Rebuild the virtual address from the indexes */
				uint64_t vaddr = (idx_256tb << SHIFT_1GB) | (idx_1gb << SHIFT_2MB);

				if (contig_end == UINT64_MAX) {
					contig_end = vaddr;
				}
				contig_start = vaddr;
			} else {
				if (contig_end != UINT64_MAX) {
					/* End of of a virtually contiguous range */
					map->ops.notify_cb(map->cb_ctx, map,
							   SPDK_MEM_MAP_NOTIFY_UNREGISTER,
							   (void *)contig_start,
							   contig_end - contig_start + VALUE_2MB);
					idx_1gb++;
				}
				contig_end = UINT64_MAX;
			}
		}
		idx_1gb = sizeof(map_1gb->map) / sizeof(map_1gb->map[0]) - 1;
	}

	pthread_mutex_unlock(&g_mem_reg_map->mutex);
	return rc;
}

struct spdk_mem_map *
spdk_mem_map_alloc(uint64_t default_translation, const struct spdk_mem_map_ops *ops, void *cb_ctx)
{
	struct spdk_mem_map *map;
	int rc;

	map = calloc(1, sizeof(*map));
	if (map == NULL) {
		return NULL;
	}

	if (pthread_mutex_init(&map->mutex, NULL)) {
		free(map);
		return NULL;
	}

	map->default_translation = default_translation;
	map->cb_ctx = cb_ctx;
	if (ops) {
		map->ops = *ops;
	}

	if (ops && ops->notify_cb) {
		pthread_mutex_lock(&g_spdk_mem_map_mutex);
		rc = mem_map_notify_walk(map, SPDK_MEM_MAP_NOTIFY_REGISTER);
		if (rc != 0) {
			pthread_mutex_unlock(&g_spdk_mem_map_mutex);
			DEBUG_PRINT("Initial mem_map notify failed\n");
			pthread_mutex_destroy(&map->mutex);
			free(map);
			return NULL;
		}
		TAILQ_INSERT_TAIL(&g_spdk_mem_maps, map, tailq);
		pthread_mutex_unlock(&g_spdk_mem_map_mutex);
	}

	return map;
}

void
spdk_mem_map_free(struct spdk_mem_map **pmap)
{
	struct spdk_mem_map *map;
	size_t i;

	if (!pmap) {
		return;
	}

	map = *pmap;

	if (!map) {
		return;
	}

	if (map->ops.notify_cb) {
		pthread_mutex_lock(&g_spdk_mem_map_mutex);
		mem_map_notify_walk(map, SPDK_MEM_MAP_NOTIFY_UNREGISTER);
		TAILQ_REMOVE(&g_spdk_mem_maps, map, tailq);
		pthread_mutex_unlock(&g_spdk_mem_map_mutex);
	}

	for (i = 0; i < sizeof(map->map_256tb.map) / sizeof(map->map_256tb.map[0]); i++) {
		free(map->map_256tb.map[i]);
	}

	pthread_mutex_destroy(&map->mutex);

	free(map);
	*pmap = NULL;
}

int
spdk_mem_register(void *vaddr, size_t len)
{
	struct spdk_mem_map *map;
	int rc;
	void *seg_vaddr;
	size_t seg_len;
	uint64_t reg;

	if ((uintptr_t)vaddr & ~MASK_256TB) {
		DEBUG_PRINT("invalid usermode virtual address %p\n", vaddr);
		return -EINVAL;
	}

	if (((uintptr_t)vaddr & MASK_2MB) || (len & MASK_2MB)) {
		DEBUG_PRINT("invalid %s parameters, vaddr=%p len=%ju\n",
			    __func__, vaddr, len);
		return -EINVAL;
	}

	if (len == 0) {
		return 0;
	}

	pthread_mutex_lock(&g_spdk_mem_map_mutex);

	seg_vaddr = vaddr;
	seg_len = len;
	while (seg_len > 0) {
		reg = spdk_mem_map_translate(g_mem_reg_map, (uint64_t)seg_vaddr, NULL);
		if (reg & REG_MAP_REGISTERED) {
			pthread_mutex_unlock(&g_spdk_mem_map_mutex);
			return -EBUSY;
		}
		seg_vaddr += VALUE_2MB;
		seg_len -= VALUE_2MB;
	}

	seg_vaddr = vaddr;
	seg_len = 0;
	while (len > 0) {
		spdk_mem_map_set_translation(g_mem_reg_map, (uint64_t)vaddr, VALUE_2MB,
					     seg_len == 0 ? REG_MAP_REGISTERED | REG_MAP_NOTIFY_START : REG_MAP_REGISTERED);
		seg_len += VALUE_2MB;
		vaddr += VALUE_2MB;
		len -= VALUE_2MB;
	}

	TAILQ_FOREACH(map, &g_spdk_mem_maps, tailq) {
		rc = map->ops.notify_cb(map->cb_ctx, map, SPDK_MEM_MAP_NOTIFY_REGISTER, seg_vaddr, seg_len);
		if (rc != 0) {
			pthread_mutex_unlock(&g_spdk_mem_map_mutex);
			return rc;
		}
	}

	pthread_mutex_unlock(&g_spdk_mem_map_mutex);
	return 0;
}

int
spdk_mem_unregister(void *vaddr, size_t len)
{
	struct spdk_mem_map *map;
	int rc;
	void *seg_vaddr;
	size_t seg_len;
	uint64_t reg, newreg;

	if ((uintptr_t)vaddr & ~MASK_256TB) {
		DEBUG_PRINT("invalid usermode virtual address %p\n", vaddr);
		return -EINVAL;
	}

	if (((uintptr_t)vaddr & MASK_2MB) || (len & MASK_2MB)) {
		DEBUG_PRINT("invalid %s parameters, vaddr=%p len=%ju\n",
			    __func__, vaddr, len);
		return -EINVAL;
	}

	pthread_mutex_lock(&g_spdk_mem_map_mutex);

	/* The first page must be a start of a region. Also check if it's
	 * registered to make sure we don't return -ERANGE for non-registered
	 * regions.
	 */
	reg = spdk_mem_map_translate(g_mem_reg_map, (uint64_t)vaddr, NULL);
	if ((reg & REG_MAP_REGISTERED) && (reg & REG_MAP_NOTIFY_START) == 0) {
		pthread_mutex_unlock(&g_spdk_mem_map_mutex);
		return -ERANGE;
	}

	seg_vaddr = vaddr;
	seg_len = len;
	while (seg_len > 0) {
		reg = spdk_mem_map_translate(g_mem_reg_map, (uint64_t)seg_vaddr, NULL);
		if ((reg & REG_MAP_REGISTERED) == 0) {
			pthread_mutex_unlock(&g_spdk_mem_map_mutex);
			return -EINVAL;
		}
		seg_vaddr += VALUE_2MB;
		seg_len -= VALUE_2MB;
	}

	newreg = spdk_mem_map_translate(g_mem_reg_map, (uint64_t)seg_vaddr, NULL);
	/* If the next page is registered, it must be a start of a region as well,
	 * otherwise we'd be unregistering only a part of a region.
	 */
	if ((newreg & REG_MAP_NOTIFY_START) == 0 && (newreg & REG_MAP_REGISTERED)) {
		pthread_mutex_unlock(&g_spdk_mem_map_mutex);
		return -ERANGE;
	}
	seg_vaddr = vaddr;
	seg_len = 0;

	while (len > 0) {
		reg = spdk_mem_map_translate(g_mem_reg_map, (uint64_t)vaddr, NULL);
		spdk_mem_map_set_translation(g_mem_reg_map, (uint64_t)vaddr, VALUE_2MB, 0);

		if (seg_len > 0 && (reg & REG_MAP_NOTIFY_START)) {
			TAILQ_FOREACH_REVERSE(map, &g_spdk_mem_maps, spdk_mem_map_head, tailq) {
				rc = map->ops.notify_cb(map->cb_ctx, map, SPDK_MEM_MAP_NOTIFY_UNREGISTER, seg_vaddr, seg_len);
				if (rc != 0) {
					pthread_mutex_unlock(&g_spdk_mem_map_mutex);
					return rc;
				}
			}

			seg_vaddr = vaddr;
			seg_len = VALUE_2MB;
		} else {
			seg_len += VALUE_2MB;
		}

		vaddr += VALUE_2MB;
		len -= VALUE_2MB;
	}

	if (seg_len > 0) {
		TAILQ_FOREACH_REVERSE(map, &g_spdk_mem_maps, spdk_mem_map_head, tailq) {
			rc = map->ops.notify_cb(map->cb_ctx, map, SPDK_MEM_MAP_NOTIFY_UNREGISTER, seg_vaddr, seg_len);
			if (rc != 0) {
				pthread_mutex_unlock(&g_spdk_mem_map_mutex);
				return rc;
			}
		}
	}

	pthread_mutex_unlock(&g_spdk_mem_map_mutex);
	return 0;
}

int
spdk_mem_reserve(void *vaddr, size_t len)
{
	struct spdk_mem_map *map;
	void *seg_vaddr;
	size_t seg_len;
	uint64_t reg;

	if ((uintptr_t)vaddr & ~MASK_256TB) {
		DEBUG_PRINT("invalid usermode virtual address %p\n", vaddr);
		return -EINVAL;
	}

	if (((uintptr_t)vaddr & MASK_2MB) || (len & MASK_2MB)) {
		DEBUG_PRINT("invalid %s parameters, vaddr=%p len=%ju\n",
			    __func__, vaddr, len);
		return -EINVAL;
	}

	if (len == 0) {
		return 0;
	}

	pthread_mutex_lock(&g_spdk_mem_map_mutex);

	/* Check if any part of this range is already registered */
	seg_vaddr = vaddr;
	seg_len = len;
	while (seg_len > 0) {
		reg = spdk_mem_map_translate(g_mem_reg_map, (uint64_t)seg_vaddr, NULL);
		if (reg & REG_MAP_REGISTERED) {
			pthread_mutex_unlock(&g_spdk_mem_map_mutex);
			return -EBUSY;
		}
		seg_vaddr += VALUE_2MB;
		seg_len -= VALUE_2MB;
	}

	/* Simply set the translation to the memory map's default. This allocates the space in the
	 * map but does not provide a valid translation. */
	spdk_mem_map_set_translation(g_mem_reg_map, (uint64_t)vaddr, len,
				     g_mem_reg_map->default_translation);

	TAILQ_FOREACH(map, &g_spdk_mem_maps, tailq) {
		spdk_mem_map_set_translation(map, (uint64_t)vaddr, len, map->default_translation);
	}

	pthread_mutex_unlock(&g_spdk_mem_map_mutex);
	return 0;
}

static struct map_1gb *
mem_map_get_map_1gb(struct spdk_mem_map *map, uint64_t vfn_2mb)
{
	struct map_1gb *map_1gb;
	uint64_t idx_256tb = MAP_256TB_IDX(vfn_2mb);
	size_t i;

	if (spdk_unlikely(idx_256tb >= SPDK_COUNTOF(map->map_256tb.map))) {
		return NULL;
	}

	map_1gb = map->map_256tb.map[idx_256tb];

	if (!map_1gb) {
		pthread_mutex_lock(&map->mutex);

		/* Recheck to make sure nobody else got the mutex first. */
		map_1gb = map->map_256tb.map[idx_256tb];
		if (!map_1gb) {
			map_1gb = malloc(sizeof(struct map_1gb));
			if (map_1gb) {
				/* initialize all entries to default translation */
				for (i = 0; i < SPDK_COUNTOF(map_1gb->map); i++) {
					map_1gb->map[i].translation_2mb = map->default_translation;
				}
				map->map_256tb.map[idx_256tb] = map_1gb;
			}
		}

		pthread_mutex_unlock(&map->mutex);

		if (!map_1gb) {
			DEBUG_PRINT("allocation failed\n");
			return NULL;
		}
	}

	return map_1gb;
}

int
spdk_mem_map_set_translation(struct spdk_mem_map *map, uint64_t vaddr, uint64_t size,
			     uint64_t translation)
{
	uint64_t vfn_2mb;
	struct map_1gb *map_1gb;
	uint64_t idx_1gb;
	struct map_2mb *map_2mb;

	if ((uintptr_t)vaddr & ~MASK_256TB) {
		DEBUG_PRINT("invalid usermode virtual address %lu\n", vaddr);
		return -EINVAL;
	}

	/* For now, only 2 MB-aligned registrations are supported */
	if (((uintptr_t)vaddr & MASK_2MB) || (size & MASK_2MB)) {
		DEBUG_PRINT("invalid %s parameters, vaddr=%lu len=%ju\n",
			    __func__, vaddr, size);
		return -EINVAL;
	}

	vfn_2mb = vaddr >> SHIFT_2MB;

	while (size) {
		map_1gb = mem_map_get_map_1gb(map, vfn_2mb);
		if (!map_1gb) {
			DEBUG_PRINT("could not get %p map\n", (void *)vaddr);
			return -ENOMEM;
		}

		idx_1gb = MAP_1GB_IDX(vfn_2mb);
		map_2mb = &map_1gb->map[idx_1gb];
		map_2mb->translation_2mb = translation;

		size -= VALUE_2MB;
		vfn_2mb++;
	}

	return 0;
}

int
spdk_mem_map_clear_translation(struct spdk_mem_map *map, uint64_t vaddr, uint64_t size)
{
	return spdk_mem_map_set_translation(map, vaddr, size, map->default_translation);
}

inline uint64_t
spdk_mem_map_translate(const struct spdk_mem_map *map, uint64_t vaddr, uint64_t *size)
{
	const struct map_1gb *map_1gb;
	const struct map_2mb *map_2mb;
	uint64_t idx_256tb;
	uint64_t idx_1gb;
	uint64_t vfn_2mb;
	uint64_t cur_size;
	uint64_t prev_translation;
	uint64_t orig_translation;

	if (spdk_unlikely(vaddr & ~MASK_256TB)) {
		DEBUG_PRINT("invalid usermode virtual address %p\n", (void *)vaddr);
		return map->default_translation;
	}

	vfn_2mb = vaddr >> SHIFT_2MB;
	idx_256tb = MAP_256TB_IDX(vfn_2mb);
	idx_1gb = MAP_1GB_IDX(vfn_2mb);

	map_1gb = map->map_256tb.map[idx_256tb];
	if (spdk_unlikely(!map_1gb)) {
		return map->default_translation;
	}

	cur_size = VALUE_2MB - _2MB_OFFSET(vaddr);
	map_2mb = &map_1gb->map[idx_1gb];
	if (size == NULL || map->ops.are_contiguous == NULL ||
	    map_2mb->translation_2mb == map->default_translation) {
		if (size != NULL) {
			*size = spdk_min(*size, cur_size);
		}
		return map_2mb->translation_2mb;
	}

	orig_translation = map_2mb->translation_2mb;
	prev_translation = orig_translation;
	while (cur_size < *size) {
		vfn_2mb++;
		idx_256tb = MAP_256TB_IDX(vfn_2mb);
		idx_1gb = MAP_1GB_IDX(vfn_2mb);

		map_1gb = map->map_256tb.map[idx_256tb];
		if (spdk_unlikely(!map_1gb)) {
			break;
		}

		map_2mb = &map_1gb->map[idx_1gb];
		if (!map->ops.are_contiguous(prev_translation, map_2mb->translation_2mb)) {
			break;
		}

		cur_size += VALUE_2MB;
		prev_translation = map_2mb->translation_2mb;
	}

	*size = spdk_min(*size, cur_size);
	return orig_translation;
}

static void
memory_hotplug_cb(enum rte_mem_event event_type,
		  const void *addr, size_t len, void *arg)
{
	if (event_type == RTE_MEM_EVENT_ALLOC) {
		spdk_mem_register((void *)addr, len);

#if RTE_VERSION >= RTE_VERSION_NUM(19, 02, 0, 0)
		if (!spdk_env_dpdk_external_init()) {
			return;
		}
#endif

		/* Prior to DPDK 19.02, we have to worry about DPDK
		 * freeing memory in different units than it was allocated.
		 * That doesn't work with things like RDMA MRs.  So for
		 * those versions of DPDK, mark each segment so that DPDK
		 * won't later free it.  That ensures we don't have to deal
		 * with that scenario.
		 *
		 * DPDK 19.02 added the --match-allocations RTE flag to
		 * avoid this condition.
		 *
		 * Note: if the user initialized DPDK separately, we can't
		 * be sure that --match-allocations was specified, so need
		 * to still mark the segments so they aren't freed.
		 */
		while (len > 0) {
			struct rte_memseg *seg;

			seg = rte_mem_virt2memseg(addr, NULL);
			assert(seg != NULL);
			seg->flags |= RTE_MEMSEG_FLAG_DO_NOT_FREE;
			addr = (void *)((uintptr_t)addr + seg->hugepage_sz);
			len -= seg->hugepage_sz;
		}
	} else if (event_type == RTE_MEM_EVENT_FREE) {
		spdk_mem_unregister((void *)addr, len);
	}
}

static int
memory_iter_cb(const struct rte_memseg_list *msl,
	       const struct rte_memseg *ms, size_t len, void *arg)
{
	return spdk_mem_register(ms->addr, len);
}

int
mem_map_init(bool legacy_mem)
{
	g_legacy_mem = legacy_mem;

	g_mem_reg_map = spdk_mem_map_alloc(0, NULL, NULL);
	if (g_mem_reg_map == NULL) {
		DEBUG_PRINT("memory registration map allocation failed\n");
		return -ENOMEM;
	}

	/*
	 * Walk all DPDK memory segments and register them
	 * with the master memory map
	 */
	rte_mem_event_callback_register("spdk", memory_hotplug_cb, NULL);
	rte_memseg_contig_walk(memory_iter_cb, NULL);
	return 0;
}

bool
spdk_iommu_is_enabled(void)
{
#if VFIO_ENABLED
	return g_vfio.enabled && !g_vfio.noiommu_enabled;
#else
	return false;
#endif
}

struct spdk_vtophys_pci_device {
	struct rte_pci_device *pci_device;
	TAILQ_ENTRY(spdk_vtophys_pci_device) tailq;
};

static pthread_mutex_t g_vtophys_pci_devices_mutex = PTHREAD_MUTEX_INITIALIZER;
static TAILQ_HEAD(, spdk_vtophys_pci_device) g_vtophys_pci_devices =
	TAILQ_HEAD_INITIALIZER(g_vtophys_pci_devices);

static struct spdk_mem_map *g_vtophys_map;
static struct spdk_mem_map *g_phys_ref_map;

#if VFIO_ENABLED
static int
vtophys_iommu_map_dma(uint64_t vaddr, uint64_t iova, uint64_t size)
{
	struct spdk_vfio_dma_map *dma_map;
	uint64_t refcount;
	int ret;

	refcount = spdk_mem_map_translate(g_phys_ref_map, iova, NULL);
	assert(refcount < UINT64_MAX);
	if (refcount > 0) {
		spdk_mem_map_set_translation(g_phys_ref_map, iova, size, refcount + 1);
		return 0;
	}

	dma_map = calloc(1, sizeof(*dma_map));
	if (dma_map == NULL) {
		return -ENOMEM;
	}

	dma_map->map.argsz = sizeof(dma_map->map);
	dma_map->map.flags = VFIO_DMA_MAP_FLAG_READ | VFIO_DMA_MAP_FLAG_WRITE;
	dma_map->map.vaddr = vaddr;
	dma_map->map.iova = iova;
	dma_map->map.size = size;

	dma_map->unmap.argsz = sizeof(dma_map->unmap);
	dma_map->unmap.flags = 0;
	dma_map->unmap.iova = iova;
	dma_map->unmap.size = size;

	pthread_mutex_lock(&g_vfio.mutex);
	if (g_vfio.device_ref == 0) {
		/* VFIO requires at least one device (IOMMU group) to be added to
		 * a VFIO container before it is possible to perform any IOMMU
		 * operations on that container. This memory will be mapped once
		 * the first device (IOMMU group) is hotplugged.
		 *
		 * Since the vfio container is managed internally by DPDK, it is
		 * also possible that some device is already in that container, but
		 * it's not managed by SPDK -  e.g. an NIC attached internally
		 * inside DPDK. We could map the memory straight away in such
		 * scenario, but there's no need to do it. DPDK devices clearly
		 * don't need our mappings and hence we defer the mapping
		 * unconditionally until the first SPDK-managed device is
		 * hotplugged.
		 */
		goto out_insert;
	}

	ret = ioctl(g_vfio.fd, VFIO_IOMMU_MAP_DMA, &dma_map->map);
	if (ret) {
		DEBUG_PRINT("Cannot set up DMA mapping, error %d\n", errno);
		pthread_mutex_unlock(&g_vfio.mutex);
		free(dma_map);
		return ret;
	}

out_insert:
	TAILQ_INSERT_TAIL(&g_vfio.maps, dma_map, tailq);
	pthread_mutex_unlock(&g_vfio.mutex);
	spdk_mem_map_set_translation(g_phys_ref_map, iova, size, refcount + 1);
	return 0;
}

static int
vtophys_iommu_unmap_dma(uint64_t iova, uint64_t size)
{
	struct spdk_vfio_dma_map *dma_map;
	uint64_t refcount;
	int ret;

	pthread_mutex_lock(&g_vfio.mutex);
	TAILQ_FOREACH(dma_map, &g_vfio.maps, tailq) {
		if (dma_map->map.iova == iova) {
			break;
		}
	}

	if (dma_map == NULL) {
		DEBUG_PRINT("Cannot clear DMA mapping for IOVA %"PRIx64" - it's not mapped\n", iova);
		pthread_mutex_unlock(&g_vfio.mutex);
		return -ENXIO;
	}

	refcount = spdk_mem_map_translate(g_phys_ref_map, iova, NULL);
	assert(refcount < UINT64_MAX);
	if (refcount > 0) {
		spdk_mem_map_set_translation(g_phys_ref_map, iova, size, refcount - 1);
	}

	/* We still have outstanding references, don't clear it. */
	if (refcount > 1) {
		pthread_mutex_unlock(&g_vfio.mutex);
		return 0;
	}

	/** don't support partial or multiple-page unmap for now */
	assert(dma_map->map.size == size);

	if (g_vfio.device_ref == 0) {
		/* Memory is not mapped anymore, just remove it's references */
		goto out_remove;
	}


	ret = ioctl(g_vfio.fd, VFIO_IOMMU_UNMAP_DMA, &dma_map->unmap);
	if (ret) {
		DEBUG_PRINT("Cannot clear DMA mapping, error %d\n", errno);
		pthread_mutex_unlock(&g_vfio.mutex);
		return ret;
	}

out_remove:
	TAILQ_REMOVE(&g_vfio.maps, dma_map, tailq);
	pthread_mutex_unlock(&g_vfio.mutex);
	free(dma_map);
	return 0;
}
#endif

static uint64_t
vtophys_get_paddr_memseg(uint64_t vaddr)
{
	uintptr_t paddr;
	struct rte_memseg *seg;

	seg = rte_mem_virt2memseg((void *)(uintptr_t)vaddr, NULL);
	if (seg != NULL) {
		paddr = seg->phys_addr;
		if (paddr == RTE_BAD_IOVA) {
			return SPDK_VTOPHYS_ERROR;
		}
		paddr += (vaddr - (uintptr_t)seg->addr);
		return paddr;
	}

	return SPDK_VTOPHYS_ERROR;
}

/* Try to get the paddr from /proc/self/pagemap */
static uint64_t
vtophys_get_paddr_pagemap(uint64_t vaddr)
{
	uintptr_t paddr;

	/* Silence static analyzers */
	assert(vaddr != 0);
	paddr = rte_mem_virt2iova((void *)vaddr);
	if (paddr == RTE_BAD_IOVA) {
		/*
		 * The vaddr may be valid but doesn't have a backing page
		 * assigned yet.  Touch the page to ensure a backing page
		 * gets assigned, then try to translate again.
		 */
		rte_atomic64_read((rte_atomic64_t *)vaddr);
		paddr = rte_mem_virt2iova((void *)vaddr);
	}
	if (paddr == RTE_BAD_IOVA) {
		/* Unable to get to the physical address. */
		return SPDK_VTOPHYS_ERROR;
	}

	return paddr;
}

/* Try to get the paddr from pci devices */
static uint64_t
vtophys_get_paddr_pci(uint64_t vaddr)
{
	struct spdk_vtophys_pci_device *vtophys_dev;
	uintptr_t paddr;
	struct rte_pci_device	*dev;
	struct rte_mem_resource *res;
	unsigned r;

	pthread_mutex_lock(&g_vtophys_pci_devices_mutex);
	TAILQ_FOREACH(vtophys_dev, &g_vtophys_pci_devices, tailq) {
		dev = vtophys_dev->pci_device;

		for (r = 0; r < PCI_MAX_RESOURCE; r++) {
			res = &dev->mem_resource[r];
			if (res->phys_addr && vaddr >= (uint64_t)res->addr &&
			    vaddr < (uint64_t)res->addr + res->len) {
				paddr = res->phys_addr + (vaddr - (uint64_t)res->addr);
				DEBUG_PRINT("%s: %p -> %p\n", __func__, (void *)vaddr,
					    (void *)paddr);
				pthread_mutex_unlock(&g_vtophys_pci_devices_mutex);
				return paddr;
			}
		}
	}
	pthread_mutex_unlock(&g_vtophys_pci_devices_mutex);

	return  SPDK_VTOPHYS_ERROR;
}

static int
vtophys_notify(void *cb_ctx, struct spdk_mem_map *map,
	       enum spdk_mem_map_notify_action action,
	       void *vaddr, size_t len)
{
	int rc = 0, pci_phys = 0;
	uint64_t paddr;

	if ((uintptr_t)vaddr & ~MASK_256TB) {
		DEBUG_PRINT("invalid usermode virtual address %p\n", vaddr);
		return -EINVAL;
	}

	if (((uintptr_t)vaddr & MASK_2MB) || (len & MASK_2MB)) {
		DEBUG_PRINT("invalid parameters, vaddr=%p len=%ju\n",
			    vaddr, len);
		return -EINVAL;
	}

	/* Get the physical address from the DPDK memsegs */
	paddr = vtophys_get_paddr_memseg((uint64_t)vaddr);

	switch (action) {
	case SPDK_MEM_MAP_NOTIFY_REGISTER:
		if (paddr == SPDK_VTOPHYS_ERROR) {
			/* This is not an address that DPDK is managing. */
#if VFIO_ENABLED
			enum rte_iova_mode iova_mode;

#if RTE_VERSION >= RTE_VERSION_NUM(19, 11, 0, 0)
			iova_mode = rte_eal_iova_mode();
#else
			iova_mode = rte_eal_get_configuration()->iova_mode;
#endif

			if (spdk_iommu_is_enabled() && iova_mode == RTE_IOVA_VA) {
				/* We'll use the virtual address as the iova to match DPDK. */
				paddr = (uint64_t)vaddr;
				rc = vtophys_iommu_map_dma((uint64_t)vaddr, paddr, len);
				if (rc) {
					return -EFAULT;
				}
				while (len > 0) {
					rc = spdk_mem_map_set_translation(map, (uint64_t)vaddr, VALUE_2MB, paddr);
					if (rc != 0) {
						return rc;
					}
					vaddr += VALUE_2MB;
					paddr += VALUE_2MB;
					len -= VALUE_2MB;
				}
			} else
#endif
			{
				/* Get the physical address from /proc/self/pagemap. */
				paddr = vtophys_get_paddr_pagemap((uint64_t)vaddr);
				if (paddr == SPDK_VTOPHYS_ERROR) {
					/* Get the physical address from PCI devices */
					paddr = vtophys_get_paddr_pci((uint64_t)vaddr);
					if (paddr == SPDK_VTOPHYS_ERROR) {
						DEBUG_PRINT("could not get phys addr for %p\n", vaddr);
						return -EFAULT;
					}
					/* The beginning of this address range points to a PCI resource,
					 * so the rest must point to a PCI resource as well.
					 */
					pci_phys = 1;
				}

				/* Get paddr for each 2MB chunk in this address range */
				while (len > 0) {
					/* Get the physical address from /proc/self/pagemap. */
					if (pci_phys) {
						paddr = vtophys_get_paddr_pci((uint64_t)vaddr);
					} else {
						paddr = vtophys_get_paddr_pagemap((uint64_t)vaddr);
					}

					if (paddr == SPDK_VTOPHYS_ERROR) {
						DEBUG_PRINT("could not get phys addr for %p\n", vaddr);
						return -EFAULT;
					}

					/* Since PCI paddr can break the 2MiB physical alignment skip this check for that. */
					if (!pci_phys && (paddr & MASK_2MB)) {
						DEBUG_PRINT("invalid paddr 0x%" PRIx64 " - must be 2MB aligned\n", paddr);
						return -EINVAL;
					}
#if VFIO_ENABLED
					/* If the IOMMU is on, but DPDK is using iova-mode=pa, we want to register this memory
					 * with the IOMMU using the physical address to match. */
					if (spdk_iommu_is_enabled()) {
						rc = vtophys_iommu_map_dma((uint64_t)vaddr, paddr, VALUE_2MB);
						if (rc) {
							DEBUG_PRINT("Unable to assign vaddr %p to paddr 0x%" PRIx64 "\n", vaddr, paddr);
							return -EFAULT;
						}
					}
#endif

					rc = spdk_mem_map_set_translation(map, (uint64_t)vaddr, VALUE_2MB, paddr);
					if (rc != 0) {
						return rc;
					}

					vaddr += VALUE_2MB;
					len -= VALUE_2MB;
				}
			}
		} else {
			/* This is an address managed by DPDK. Just setup the translations. */
			while (len > 0) {
				paddr = vtophys_get_paddr_memseg((uint64_t)vaddr);
				if (paddr == SPDK_VTOPHYS_ERROR) {
					DEBUG_PRINT("could not get phys addr for %p\n", vaddr);
					return -EFAULT;
				}

				rc = spdk_mem_map_set_translation(map, (uint64_t)vaddr, VALUE_2MB, paddr);
				if (rc != 0) {
					return rc;
				}

				vaddr += VALUE_2MB;
				len -= VALUE_2MB;
			}
		}

		break;
	case SPDK_MEM_MAP_NOTIFY_UNREGISTER:
#if VFIO_ENABLED
		if (paddr == SPDK_VTOPHYS_ERROR) {
			/*
			 * This is not an address that DPDK is managing. If vfio is enabled,
			 * we need to unmap the range from the IOMMU
			 */
			if (spdk_iommu_is_enabled()) {
				uint64_t buffer_len = len;
				uint8_t *va = vaddr;
				enum rte_iova_mode iova_mode;

#if RTE_VERSION >= RTE_VERSION_NUM(19, 11, 0, 0)
				iova_mode = rte_eal_iova_mode();
#else
				iova_mode = rte_eal_get_configuration()->iova_mode;
#endif
				/*
				 * In virtual address mode, the region is contiguous and can be done in
				 * one unmap.
				 */
				if (iova_mode == RTE_IOVA_VA) {
					paddr = spdk_mem_map_translate(map, (uint64_t)va, &buffer_len);
					if (buffer_len != len || paddr != (uintptr_t)va) {
						DEBUG_PRINT("Unmapping %p with length %lu failed because "
							    "translation had address 0x%" PRIx64 " and length %lu\n",
							    va, len, paddr, buffer_len);
						return -EINVAL;
					}
					rc = vtophys_iommu_unmap_dma(paddr, len);
					if (rc) {
						DEBUG_PRINT("Failed to iommu unmap paddr 0x%" PRIx64 "\n", paddr);
						return -EFAULT;
					}
				} else if (iova_mode == RTE_IOVA_PA) {
					/* Get paddr for each 2MB chunk in this address range */
					while (buffer_len > 0) {
						paddr = spdk_mem_map_translate(map, (uint64_t)va, NULL);

						if (paddr == SPDK_VTOPHYS_ERROR || buffer_len < VALUE_2MB) {
							DEBUG_PRINT("could not get phys addr for %p\n", va);
							return -EFAULT;
						}

						rc = vtophys_iommu_unmap_dma(paddr, VALUE_2MB);
						if (rc) {
							DEBUG_PRINT("Failed to iommu unmap paddr 0x%" PRIx64 "\n", paddr);
							return -EFAULT;
						}

						va += VALUE_2MB;
						buffer_len -= VALUE_2MB;
					}
				}
			}
		}
#endif
		while (len > 0) {
			rc = spdk_mem_map_clear_translation(map, (uint64_t)vaddr, VALUE_2MB);
			if (rc != 0) {
				return rc;
			}

			vaddr += VALUE_2MB;
			len -= VALUE_2MB;
		}

		break;
	default:
		SPDK_UNREACHABLE();
	}

	return rc;
}

static int
vtophys_check_contiguous_entries(uint64_t paddr1, uint64_t paddr2)
{
	/* This function is always called with paddrs for two subsequent
	 * 2MB chunks in virtual address space, so those chunks will be only
	 * physically contiguous if the physical addresses are 2MB apart
	 * from each other as well.
	 */
	return (paddr2 - paddr1 == VALUE_2MB);
}

#if VFIO_ENABLED

static bool
vfio_enabled(void)
{
	return rte_vfio_is_enabled("vfio_pci");
}

/* Check if IOMMU is enabled on the system */
static bool
has_iommu_groups(void)
{
	struct dirent *d;
	int count = 0;
	DIR *dir = opendir("/sys/kernel/iommu_groups");

	if (dir == NULL) {
		return false;
	}

	while (count < 3 && (d = readdir(dir)) != NULL) {
		count++;
	}

	closedir(dir);
	/* there will always be ./ and ../ entries */
	return count > 2;
}

static bool
vfio_noiommu_enabled(void)
{
	return rte_vfio_noiommu_is_enabled();
}

static void
vtophys_iommu_init(void)
{
	char proc_fd_path[PATH_MAX + 1];
	char link_path[PATH_MAX + 1];
	const char vfio_path[] = "/dev/vfio/vfio";
	DIR *dir;
	struct dirent *d;

	if (!vfio_enabled()) {
		return;
	}

	if (vfio_noiommu_enabled()) {
		g_vfio.noiommu_enabled = true;
	} else if (!has_iommu_groups()) {
		return;
	}

	dir = opendir("/proc/self/fd");
	if (!dir) {
		DEBUG_PRINT("Failed to open /proc/self/fd (%d)\n", errno);
		return;
	}

	while ((d = readdir(dir)) != NULL) {
		if (d->d_type != DT_LNK) {
			continue;
		}

		snprintf(proc_fd_path, sizeof(proc_fd_path), "/proc/self/fd/%s", d->d_name);
		if (readlink(proc_fd_path, link_path, sizeof(link_path)) != (sizeof(vfio_path) - 1)) {
			continue;
		}

		if (memcmp(link_path, vfio_path, sizeof(vfio_path) - 1) == 0) {
			sscanf(d->d_name, "%d", &g_vfio.fd);
			break;
		}
	}

	closedir(dir);

	if (g_vfio.fd < 0) {
		DEBUG_PRINT("Failed to discover DPDK VFIO container fd.\n");
		return;
	}

	g_vfio.enabled = true;

	return;
}
#endif

void
vtophys_pci_device_added(struct rte_pci_device *pci_device)
{
	struct spdk_vtophys_pci_device *vtophys_dev;

	pthread_mutex_lock(&g_vtophys_pci_devices_mutex);

	vtophys_dev = calloc(1, sizeof(*vtophys_dev));
	if (vtophys_dev) {
		vtophys_dev->pci_device = pci_device;
		TAILQ_INSERT_TAIL(&g_vtophys_pci_devices, vtophys_dev, tailq);
	} else {
		DEBUG_PRINT("Memory allocation error\n");
	}
	pthread_mutex_unlock(&g_vtophys_pci_devices_mutex);

#if VFIO_ENABLED
	struct spdk_vfio_dma_map *dma_map;
	int ret;

	if (!g_vfio.enabled) {
		return;
	}

	pthread_mutex_lock(&g_vfio.mutex);
	g_vfio.device_ref++;
	if (g_vfio.device_ref > 1) {
		pthread_mutex_unlock(&g_vfio.mutex);
		return;
	}

	/* This is the first SPDK device using DPDK vfio. This means that the first
	 * IOMMU group might have been just been added to the DPDK vfio container.
	 * From this point it is certain that the memory can be mapped now.
	 */
	TAILQ_FOREACH(dma_map, &g_vfio.maps, tailq) {
		ret = ioctl(g_vfio.fd, VFIO_IOMMU_MAP_DMA, &dma_map->map);
		if (ret) {
			DEBUG_PRINT("Cannot update DMA mapping, error %d\n", errno);
			break;
		}
	}
	pthread_mutex_unlock(&g_vfio.mutex);
#endif
}

void
vtophys_pci_device_removed(struct rte_pci_device *pci_device)
{
	struct spdk_vtophys_pci_device *vtophys_dev;

	pthread_mutex_lock(&g_vtophys_pci_devices_mutex);
	TAILQ_FOREACH(vtophys_dev, &g_vtophys_pci_devices, tailq) {
		if (vtophys_dev->pci_device == pci_device) {
			TAILQ_REMOVE(&g_vtophys_pci_devices, vtophys_dev, tailq);
			free(vtophys_dev);
			break;
		}
	}
	pthread_mutex_unlock(&g_vtophys_pci_devices_mutex);

#if VFIO_ENABLED
	struct spdk_vfio_dma_map *dma_map;
	int ret;

	if (!g_vfio.enabled) {
		return;
	}

	pthread_mutex_lock(&g_vfio.mutex);
	assert(g_vfio.device_ref > 0);
	g_vfio.device_ref--;
	if (g_vfio.device_ref > 0) {
		pthread_mutex_unlock(&g_vfio.mutex);
		return;
	}

	/* This is the last SPDK device using DPDK vfio. If DPDK doesn't have
	 * any additional devices using it's vfio container, all the mappings
	 * will be automatically removed by the Linux vfio driver. We unmap
	 * the memory manually to be able to easily re-map it later regardless
	 * of other, external factors.
	 */
	TAILQ_FOREACH(dma_map, &g_vfio.maps, tailq) {
		ret = ioctl(g_vfio.fd, VFIO_IOMMU_UNMAP_DMA, &dma_map->unmap);
		if (ret) {
			DEBUG_PRINT("Cannot unmap DMA memory, error %d\n", errno);
			break;
		}
	}
	pthread_mutex_unlock(&g_vfio.mutex);
#endif
}

int
vtophys_init(void)
{
	const struct spdk_mem_map_ops vtophys_map_ops = {
		.notify_cb = vtophys_notify,
		.are_contiguous = vtophys_check_contiguous_entries,
	};

	const struct spdk_mem_map_ops phys_ref_map_ops = {
		.notify_cb = NULL,
		.are_contiguous = NULL,
	};

#if VFIO_ENABLED
	vtophys_iommu_init();
#endif

	g_phys_ref_map = spdk_mem_map_alloc(0, &phys_ref_map_ops, NULL);
	if (g_phys_ref_map == NULL) {
		DEBUG_PRINT("phys_ref map allocation failed.\n");
		return -ENOMEM;
	}

	g_vtophys_map = spdk_mem_map_alloc(SPDK_VTOPHYS_ERROR, &vtophys_map_ops, NULL);
	if (g_vtophys_map == NULL) {
		DEBUG_PRINT("vtophys map allocation failed\n");
		return -ENOMEM;
	}
	return 0;
}

uint64_t
spdk_vtophys(void *buf, uint64_t *size)
{
	uint64_t vaddr, paddr_2mb;

	vaddr = (uint64_t)buf;
	paddr_2mb = spdk_mem_map_translate(g_vtophys_map, vaddr, size);

	/*
	 * SPDK_VTOPHYS_ERROR has all bits set, so if the lookup returned SPDK_VTOPHYS_ERROR,
	 * we will still bitwise-or it with the buf offset below, but the result will still be
	 * SPDK_VTOPHYS_ERROR. However now that we do + rather than | (due to PCI vtophys being
	 * unaligned) we must now check the return value before addition.
	 */
	SPDK_STATIC_ASSERT(SPDK_VTOPHYS_ERROR == UINT64_C(-1), "SPDK_VTOPHYS_ERROR should be all 1s");
	if (paddr_2mb == SPDK_VTOPHYS_ERROR) {
		return SPDK_VTOPHYS_ERROR;
	} else {
		return paddr_2mb + (vaddr & MASK_2MB);
	}
}