qdev-monitor: Set properties after parent is assigned in device_add
[qemu.git] / migration-rdma.c
1 /*
2 * RDMA protocol and interfaces
3 *
4 * Copyright IBM, Corp. 2010-2013
5 *
6 * Authors:
7 * Michael R. Hines <mrhines@us.ibm.com>
8 * Jiuxing Liu <jl@us.ibm.com>
9 *
10 * This work is licensed under the terms of the GNU GPL, version 2 or
11 * later. See the COPYING file in the top-level directory.
12 *
13 */
14 #include "qemu-common.h"
15 #include "migration/migration.h"
16 #include "migration/qemu-file.h"
17 #include "exec/cpu-common.h"
18 #include "qemu/main-loop.h"
19 #include "qemu/sockets.h"
20 #include "qemu/bitmap.h"
21 #include "block/coroutine.h"
22 #include <stdio.h>
23 #include <sys/types.h>
24 #include <sys/socket.h>
25 #include <netdb.h>
26 #include <arpa/inet.h>
27 #include <string.h>
28 #include <rdma/rdma_cma.h>
29
30 //#define DEBUG_RDMA
31 //#define DEBUG_RDMA_VERBOSE
32 //#define DEBUG_RDMA_REALLY_VERBOSE
33
34 #ifdef DEBUG_RDMA
35 #define DPRINTF(fmt, ...) \
36 do { printf("rdma: " fmt, ## __VA_ARGS__); } while (0)
37 #else
38 #define DPRINTF(fmt, ...) \
39 do { } while (0)
40 #endif
41
42 #ifdef DEBUG_RDMA_VERBOSE
43 #define DDPRINTF(fmt, ...) \
44 do { printf("rdma: " fmt, ## __VA_ARGS__); } while (0)
45 #else
46 #define DDPRINTF(fmt, ...) \
47 do { } while (0)
48 #endif
49
50 #ifdef DEBUG_RDMA_REALLY_VERBOSE
51 #define DDDPRINTF(fmt, ...) \
52 do { printf("rdma: " fmt, ## __VA_ARGS__); } while (0)
53 #else
54 #define DDDPRINTF(fmt, ...) \
55 do { } while (0)
56 #endif
57
58 /*
59 * Print and error on both the Monitor and the Log file.
60 */
61 #define ERROR(errp, fmt, ...) \
62 do { \
63 fprintf(stderr, "RDMA ERROR: " fmt "\n", ## __VA_ARGS__); \
64 if (errp && (*(errp) == NULL)) { \
65 error_setg(errp, "RDMA ERROR: " fmt, ## __VA_ARGS__); \
66 } \
67 } while (0)
68
69 #define RDMA_RESOLVE_TIMEOUT_MS 10000
70
71 /* Do not merge data if larger than this. */
72 #define RDMA_MERGE_MAX (2 * 1024 * 1024)
73 #define RDMA_SIGNALED_SEND_MAX (RDMA_MERGE_MAX / 4096)
74
75 #define RDMA_REG_CHUNK_SHIFT 20 /* 1 MB */
76
77 /*
78 * This is only for non-live state being migrated.
79 * Instead of RDMA_WRITE messages, we use RDMA_SEND
80 * messages for that state, which requires a different
81 * delivery design than main memory.
82 */
83 #define RDMA_SEND_INCREMENT 32768
84
85 /*
86 * Maximum size infiniband SEND message
87 */
88 #define RDMA_CONTROL_MAX_BUFFER (512 * 1024)
89 #define RDMA_CONTROL_MAX_COMMANDS_PER_MESSAGE 4096
90
91 #define RDMA_CONTROL_VERSION_CURRENT 1
92 /*
93 * Capabilities for negotiation.
94 */
95 #define RDMA_CAPABILITY_PIN_ALL 0x01
96
97 /*
98 * Add the other flags above to this list of known capabilities
99 * as they are introduced.
100 */
101 static uint32_t known_capabilities = RDMA_CAPABILITY_PIN_ALL;
102
103 #define CHECK_ERROR_STATE() \
104 do { \
105 if (rdma->error_state) { \
106 if (!rdma->error_reported) { \
107 fprintf(stderr, "RDMA is in an error state waiting migration" \
108 " to abort!\n"); \
109 rdma->error_reported = 1; \
110 } \
111 return rdma->error_state; \
112 } \
113 } while (0);
114
115 /*
116 * A work request ID is 64-bits and we split up these bits
117 * into 3 parts:
118 *
119 * bits 0-15 : type of control message, 2^16
120 * bits 16-29: ram block index, 2^14
121 * bits 30-63: ram block chunk number, 2^34
122 *
123 * The last two bit ranges are only used for RDMA writes,
124 * in order to track their completion and potentially
125 * also track unregistration status of the message.
126 */
127 #define RDMA_WRID_TYPE_SHIFT 0UL
128 #define RDMA_WRID_BLOCK_SHIFT 16UL
129 #define RDMA_WRID_CHUNK_SHIFT 30UL
130
131 #define RDMA_WRID_TYPE_MASK \
132 ((1UL << RDMA_WRID_BLOCK_SHIFT) - 1UL)
133
134 #define RDMA_WRID_BLOCK_MASK \
135 (~RDMA_WRID_TYPE_MASK & ((1UL << RDMA_WRID_CHUNK_SHIFT) - 1UL))
136
137 #define RDMA_WRID_CHUNK_MASK (~RDMA_WRID_BLOCK_MASK & ~RDMA_WRID_TYPE_MASK)
138
139 /*
140 * RDMA migration protocol:
141 * 1. RDMA Writes (data messages, i.e. RAM)
142 * 2. IB Send/Recv (control channel messages)
143 */
144 enum {
145 RDMA_WRID_NONE = 0,
146 RDMA_WRID_RDMA_WRITE = 1,
147 RDMA_WRID_SEND_CONTROL = 2000,
148 RDMA_WRID_RECV_CONTROL = 4000,
149 };
150
151 const char *wrid_desc[] = {
152 [RDMA_WRID_NONE] = "NONE",
153 [RDMA_WRID_RDMA_WRITE] = "WRITE RDMA",
154 [RDMA_WRID_SEND_CONTROL] = "CONTROL SEND",
155 [RDMA_WRID_RECV_CONTROL] = "CONTROL RECV",
156 };
157
158 /*
159 * Work request IDs for IB SEND messages only (not RDMA writes).
160 * This is used by the migration protocol to transmit
161 * control messages (such as device state and registration commands)
162 *
163 * We could use more WRs, but we have enough for now.
164 */
165 enum {
166 RDMA_WRID_READY = 0,
167 RDMA_WRID_DATA,
168 RDMA_WRID_CONTROL,
169 RDMA_WRID_MAX,
170 };
171
172 /*
173 * SEND/RECV IB Control Messages.
174 */
175 enum {
176 RDMA_CONTROL_NONE = 0,
177 RDMA_CONTROL_ERROR,
178 RDMA_CONTROL_READY, /* ready to receive */
179 RDMA_CONTROL_QEMU_FILE, /* QEMUFile-transmitted bytes */
180 RDMA_CONTROL_RAM_BLOCKS_REQUEST, /* RAMBlock synchronization */
181 RDMA_CONTROL_RAM_BLOCKS_RESULT, /* RAMBlock synchronization */
182 RDMA_CONTROL_COMPRESS, /* page contains repeat values */
183 RDMA_CONTROL_REGISTER_REQUEST, /* dynamic page registration */
184 RDMA_CONTROL_REGISTER_RESULT, /* key to use after registration */
185 RDMA_CONTROL_REGISTER_FINISHED, /* current iteration finished */
186 RDMA_CONTROL_UNREGISTER_REQUEST, /* dynamic UN-registration */
187 RDMA_CONTROL_UNREGISTER_FINISHED, /* unpinning finished */
188 };
189
190 const char *control_desc[] = {
191 [RDMA_CONTROL_NONE] = "NONE",
192 [RDMA_CONTROL_ERROR] = "ERROR",
193 [RDMA_CONTROL_READY] = "READY",
194 [RDMA_CONTROL_QEMU_FILE] = "QEMU FILE",
195 [RDMA_CONTROL_RAM_BLOCKS_REQUEST] = "RAM BLOCKS REQUEST",
196 [RDMA_CONTROL_RAM_BLOCKS_RESULT] = "RAM BLOCKS RESULT",
197 [RDMA_CONTROL_COMPRESS] = "COMPRESS",
198 [RDMA_CONTROL_REGISTER_REQUEST] = "REGISTER REQUEST",
199 [RDMA_CONTROL_REGISTER_RESULT] = "REGISTER RESULT",
200 [RDMA_CONTROL_REGISTER_FINISHED] = "REGISTER FINISHED",
201 [RDMA_CONTROL_UNREGISTER_REQUEST] = "UNREGISTER REQUEST",
202 [RDMA_CONTROL_UNREGISTER_FINISHED] = "UNREGISTER FINISHED",
203 };
204
205 /*
206 * Memory and MR structures used to represent an IB Send/Recv work request.
207 * This is *not* used for RDMA writes, only IB Send/Recv.
208 */
209 typedef struct {
210 uint8_t control[RDMA_CONTROL_MAX_BUFFER]; /* actual buffer to register */
211 struct ibv_mr *control_mr; /* registration metadata */
212 size_t control_len; /* length of the message */
213 uint8_t *control_curr; /* start of unconsumed bytes */
214 } RDMAWorkRequestData;
215
216 /*
217 * Negotiate RDMA capabilities during connection-setup time.
218 */
219 typedef struct {
220 uint32_t version;
221 uint32_t flags;
222 } RDMACapabilities;
223
224 static void caps_to_network(RDMACapabilities *cap)
225 {
226 cap->version = htonl(cap->version);
227 cap->flags = htonl(cap->flags);
228 }
229
230 static void network_to_caps(RDMACapabilities *cap)
231 {
232 cap->version = ntohl(cap->version);
233 cap->flags = ntohl(cap->flags);
234 }
235
236 /*
237 * Representation of a RAMBlock from an RDMA perspective.
238 * This is not transmitted, only local.
239 * This and subsequent structures cannot be linked lists
240 * because we're using a single IB message to transmit
241 * the information. It's small anyway, so a list is overkill.
242 */
243 typedef struct RDMALocalBlock {
244 uint8_t *local_host_addr; /* local virtual address */
245 uint64_t remote_host_addr; /* remote virtual address */
246 uint64_t offset;
247 uint64_t length;
248 struct ibv_mr **pmr; /* MRs for chunk-level registration */
249 struct ibv_mr *mr; /* MR for non-chunk-level registration */
250 uint32_t *remote_keys; /* rkeys for chunk-level registration */
251 uint32_t remote_rkey; /* rkeys for non-chunk-level registration */
252 int index; /* which block are we */
253 bool is_ram_block;
254 int nb_chunks;
255 unsigned long *transit_bitmap;
256 unsigned long *unregister_bitmap;
257 } RDMALocalBlock;
258
259 /*
260 * Also represents a RAMblock, but only on the dest.
261 * This gets transmitted by the dest during connection-time
262 * to the source VM and then is used to populate the
263 * corresponding RDMALocalBlock with
264 * the information needed to perform the actual RDMA.
265 */
266 typedef struct QEMU_PACKED RDMARemoteBlock {
267 uint64_t remote_host_addr;
268 uint64_t offset;
269 uint64_t length;
270 uint32_t remote_rkey;
271 uint32_t padding;
272 } RDMARemoteBlock;
273
274 static uint64_t htonll(uint64_t v)
275 {
276 union { uint32_t lv[2]; uint64_t llv; } u;
277 u.lv[0] = htonl(v >> 32);
278 u.lv[1] = htonl(v & 0xFFFFFFFFULL);
279 return u.llv;
280 }
281
282 static uint64_t ntohll(uint64_t v) {
283 union { uint32_t lv[2]; uint64_t llv; } u;
284 u.llv = v;
285 return ((uint64_t)ntohl(u.lv[0]) << 32) | (uint64_t) ntohl(u.lv[1]);
286 }
287
288 static void remote_block_to_network(RDMARemoteBlock *rb)
289 {
290 rb->remote_host_addr = htonll(rb->remote_host_addr);
291 rb->offset = htonll(rb->offset);
292 rb->length = htonll(rb->length);
293 rb->remote_rkey = htonl(rb->remote_rkey);
294 }
295
296 static void network_to_remote_block(RDMARemoteBlock *rb)
297 {
298 rb->remote_host_addr = ntohll(rb->remote_host_addr);
299 rb->offset = ntohll(rb->offset);
300 rb->length = ntohll(rb->length);
301 rb->remote_rkey = ntohl(rb->remote_rkey);
302 }
303
304 /*
305 * Virtual address of the above structures used for transmitting
306 * the RAMBlock descriptions at connection-time.
307 * This structure is *not* transmitted.
308 */
309 typedef struct RDMALocalBlocks {
310 int nb_blocks;
311 bool init; /* main memory init complete */
312 RDMALocalBlock *block;
313 } RDMALocalBlocks;
314
315 /*
316 * Main data structure for RDMA state.
317 * While there is only one copy of this structure being allocated right now,
318 * this is the place where one would start if you wanted to consider
319 * having more than one RDMA connection open at the same time.
320 */
321 typedef struct RDMAContext {
322 char *host;
323 int port;
324
325 RDMAWorkRequestData wr_data[RDMA_WRID_MAX];
326
327 /*
328 * This is used by *_exchange_send() to figure out whether or not
329 * the initial "READY" message has already been received or not.
330 * This is because other functions may potentially poll() and detect
331 * the READY message before send() does, in which case we need to
332 * know if it completed.
333 */
334 int control_ready_expected;
335
336 /* number of outstanding writes */
337 int nb_sent;
338
339 /* store info about current buffer so that we can
340 merge it with future sends */
341 uint64_t current_addr;
342 uint64_t current_length;
343 /* index of ram block the current buffer belongs to */
344 int current_index;
345 /* index of the chunk in the current ram block */
346 int current_chunk;
347
348 bool pin_all;
349
350 /*
351 * infiniband-specific variables for opening the device
352 * and maintaining connection state and so forth.
353 *
354 * cm_id also has ibv_context, rdma_event_channel, and ibv_qp in
355 * cm_id->verbs, cm_id->channel, and cm_id->qp.
356 */
357 struct rdma_cm_id *cm_id; /* connection manager ID */
358 struct rdma_cm_id *listen_id;
359 bool connected;
360
361 struct ibv_context *verbs;
362 struct rdma_event_channel *channel;
363 struct ibv_qp *qp; /* queue pair */
364 struct ibv_comp_channel *comp_channel; /* completion channel */
365 struct ibv_pd *pd; /* protection domain */
366 struct ibv_cq *cq; /* completion queue */
367
368 /*
369 * If a previous write failed (perhaps because of a failed
370 * memory registration, then do not attempt any future work
371 * and remember the error state.
372 */
373 int error_state;
374 int error_reported;
375
376 /*
377 * Description of ram blocks used throughout the code.
378 */
379 RDMALocalBlocks local_ram_blocks;
380 RDMARemoteBlock *block;
381
382 /*
383 * Migration on *destination* started.
384 * Then use coroutine yield function.
385 * Source runs in a thread, so we don't care.
386 */
387 int migration_started_on_destination;
388
389 int total_registrations;
390 int total_writes;
391
392 int unregister_current, unregister_next;
393 uint64_t unregistrations[RDMA_SIGNALED_SEND_MAX];
394
395 GHashTable *blockmap;
396 } RDMAContext;
397
398 /*
399 * Interface to the rest of the migration call stack.
400 */
401 typedef struct QEMUFileRDMA {
402 RDMAContext *rdma;
403 size_t len;
404 void *file;
405 } QEMUFileRDMA;
406
407 /*
408 * Main structure for IB Send/Recv control messages.
409 * This gets prepended at the beginning of every Send/Recv.
410 */
411 typedef struct QEMU_PACKED {
412 uint32_t len; /* Total length of data portion */
413 uint32_t type; /* which control command to perform */
414 uint32_t repeat; /* number of commands in data portion of same type */
415 uint32_t padding;
416 } RDMAControlHeader;
417
418 static void control_to_network(RDMAControlHeader *control)
419 {
420 control->type = htonl(control->type);
421 control->len = htonl(control->len);
422 control->repeat = htonl(control->repeat);
423 }
424
425 static void network_to_control(RDMAControlHeader *control)
426 {
427 control->type = ntohl(control->type);
428 control->len = ntohl(control->len);
429 control->repeat = ntohl(control->repeat);
430 }
431
432 /*
433 * Register a single Chunk.
434 * Information sent by the source VM to inform the dest
435 * to register an single chunk of memory before we can perform
436 * the actual RDMA operation.
437 */
438 typedef struct QEMU_PACKED {
439 union QEMU_PACKED {
440 uint64_t current_addr; /* offset into the ramblock of the chunk */
441 uint64_t chunk; /* chunk to lookup if unregistering */
442 } key;
443 uint32_t current_index; /* which ramblock the chunk belongs to */
444 uint32_t padding;
445 uint64_t chunks; /* how many sequential chunks to register */
446 } RDMARegister;
447
448 static void register_to_network(RDMARegister *reg)
449 {
450 reg->key.current_addr = htonll(reg->key.current_addr);
451 reg->current_index = htonl(reg->current_index);
452 reg->chunks = htonll(reg->chunks);
453 }
454
455 static void network_to_register(RDMARegister *reg)
456 {
457 reg->key.current_addr = ntohll(reg->key.current_addr);
458 reg->current_index = ntohl(reg->current_index);
459 reg->chunks = ntohll(reg->chunks);
460 }
461
462 typedef struct QEMU_PACKED {
463 uint32_t value; /* if zero, we will madvise() */
464 uint32_t block_idx; /* which ram block index */
465 uint64_t offset; /* where in the remote ramblock this chunk */
466 uint64_t length; /* length of the chunk */
467 } RDMACompress;
468
469 static void compress_to_network(RDMACompress *comp)
470 {
471 comp->value = htonl(comp->value);
472 comp->block_idx = htonl(comp->block_idx);
473 comp->offset = htonll(comp->offset);
474 comp->length = htonll(comp->length);
475 }
476
477 static void network_to_compress(RDMACompress *comp)
478 {
479 comp->value = ntohl(comp->value);
480 comp->block_idx = ntohl(comp->block_idx);
481 comp->offset = ntohll(comp->offset);
482 comp->length = ntohll(comp->length);
483 }
484
485 /*
486 * The result of the dest's memory registration produces an "rkey"
487 * which the source VM must reference in order to perform
488 * the RDMA operation.
489 */
490 typedef struct QEMU_PACKED {
491 uint32_t rkey;
492 uint32_t padding;
493 uint64_t host_addr;
494 } RDMARegisterResult;
495
496 static void result_to_network(RDMARegisterResult *result)
497 {
498 result->rkey = htonl(result->rkey);
499 result->host_addr = htonll(result->host_addr);
500 };
501
502 static void network_to_result(RDMARegisterResult *result)
503 {
504 result->rkey = ntohl(result->rkey);
505 result->host_addr = ntohll(result->host_addr);
506 };
507
508 const char *print_wrid(int wrid);
509 static int qemu_rdma_exchange_send(RDMAContext *rdma, RDMAControlHeader *head,
510 uint8_t *data, RDMAControlHeader *resp,
511 int *resp_idx,
512 int (*callback)(RDMAContext *rdma));
513
514 static inline uint64_t ram_chunk_index(const uint8_t *start,
515 const uint8_t *host)
516 {
517 return ((uintptr_t) host - (uintptr_t) start) >> RDMA_REG_CHUNK_SHIFT;
518 }
519
520 static inline uint8_t *ram_chunk_start(const RDMALocalBlock *rdma_ram_block,
521 uint64_t i)
522 {
523 return (uint8_t *) (((uintptr_t) rdma_ram_block->local_host_addr)
524 + (i << RDMA_REG_CHUNK_SHIFT));
525 }
526
527 static inline uint8_t *ram_chunk_end(const RDMALocalBlock *rdma_ram_block,
528 uint64_t i)
529 {
530 uint8_t *result = ram_chunk_start(rdma_ram_block, i) +
531 (1UL << RDMA_REG_CHUNK_SHIFT);
532
533 if (result > (rdma_ram_block->local_host_addr + rdma_ram_block->length)) {
534 result = rdma_ram_block->local_host_addr + rdma_ram_block->length;
535 }
536
537 return result;
538 }
539
540 static int __qemu_rdma_add_block(RDMAContext *rdma, void *host_addr,
541 ram_addr_t block_offset, uint64_t length)
542 {
543 RDMALocalBlocks *local = &rdma->local_ram_blocks;
544 RDMALocalBlock *block = g_hash_table_lookup(rdma->blockmap,
545 (void *) block_offset);
546 RDMALocalBlock *old = local->block;
547
548 assert(block == NULL);
549
550 local->block = g_malloc0(sizeof(RDMALocalBlock) * (local->nb_blocks + 1));
551
552 if (local->nb_blocks) {
553 int x;
554
555 for (x = 0; x < local->nb_blocks; x++) {
556 g_hash_table_remove(rdma->blockmap, (void *)old[x].offset);
557 g_hash_table_insert(rdma->blockmap, (void *)old[x].offset,
558 &local->block[x]);
559 }
560 memcpy(local->block, old, sizeof(RDMALocalBlock) * local->nb_blocks);
561 g_free(old);
562 }
563
564 block = &local->block[local->nb_blocks];
565
566 block->local_host_addr = host_addr;
567 block->offset = block_offset;
568 block->length = length;
569 block->index = local->nb_blocks;
570 block->nb_chunks = ram_chunk_index(host_addr, host_addr + length) + 1UL;
571 block->transit_bitmap = bitmap_new(block->nb_chunks);
572 bitmap_clear(block->transit_bitmap, 0, block->nb_chunks);
573 block->unregister_bitmap = bitmap_new(block->nb_chunks);
574 bitmap_clear(block->unregister_bitmap, 0, block->nb_chunks);
575 block->remote_keys = g_malloc0(block->nb_chunks * sizeof(uint32_t));
576
577 block->is_ram_block = local->init ? false : true;
578
579 g_hash_table_insert(rdma->blockmap, (void *) block_offset, block);
580
581 DDPRINTF("Added Block: %d, addr: %" PRIu64 ", offset: %" PRIu64
582 " length: %" PRIu64 " end: %" PRIu64 " bits %" PRIu64 " chunks %d\n",
583 local->nb_blocks, (uint64_t) block->local_host_addr, block->offset,
584 block->length, (uint64_t) (block->local_host_addr + block->length),
585 BITS_TO_LONGS(block->nb_chunks) *
586 sizeof(unsigned long) * 8, block->nb_chunks);
587
588 local->nb_blocks++;
589
590 return 0;
591 }
592
593 /*
594 * Memory regions need to be registered with the device and queue pairs setup
595 * in advanced before the migration starts. This tells us where the RAM blocks
596 * are so that we can register them individually.
597 */
598 static void qemu_rdma_init_one_block(void *host_addr,
599 ram_addr_t block_offset, ram_addr_t length, void *opaque)
600 {
601 __qemu_rdma_add_block(opaque, host_addr, block_offset, length);
602 }
603
604 /*
605 * Identify the RAMBlocks and their quantity. They will be references to
606 * identify chunk boundaries inside each RAMBlock and also be referenced
607 * during dynamic page registration.
608 */
609 static int qemu_rdma_init_ram_blocks(RDMAContext *rdma)
610 {
611 RDMALocalBlocks *local = &rdma->local_ram_blocks;
612
613 assert(rdma->blockmap == NULL);
614 rdma->blockmap = g_hash_table_new(g_direct_hash, g_direct_equal);
615 memset(local, 0, sizeof *local);
616 qemu_ram_foreach_block(qemu_rdma_init_one_block, rdma);
617 DPRINTF("Allocated %d local ram block structures\n", local->nb_blocks);
618 rdma->block = (RDMARemoteBlock *) g_malloc0(sizeof(RDMARemoteBlock) *
619 rdma->local_ram_blocks.nb_blocks);
620 local->init = true;
621 return 0;
622 }
623
624 static int __qemu_rdma_delete_block(RDMAContext *rdma, ram_addr_t block_offset)
625 {
626 RDMALocalBlocks *local = &rdma->local_ram_blocks;
627 RDMALocalBlock *block = g_hash_table_lookup(rdma->blockmap,
628 (void *) block_offset);
629 RDMALocalBlock *old = local->block;
630 int x;
631
632 assert(block);
633
634 if (block->pmr) {
635 int j;
636
637 for (j = 0; j < block->nb_chunks; j++) {
638 if (!block->pmr[j]) {
639 continue;
640 }
641 ibv_dereg_mr(block->pmr[j]);
642 rdma->total_registrations--;
643 }
644 g_free(block->pmr);
645 block->pmr = NULL;
646 }
647
648 if (block->mr) {
649 ibv_dereg_mr(block->mr);
650 rdma->total_registrations--;
651 block->mr = NULL;
652 }
653
654 g_free(block->transit_bitmap);
655 block->transit_bitmap = NULL;
656
657 g_free(block->unregister_bitmap);
658 block->unregister_bitmap = NULL;
659
660 g_free(block->remote_keys);
661 block->remote_keys = NULL;
662
663 for (x = 0; x < local->nb_blocks; x++) {
664 g_hash_table_remove(rdma->blockmap, (void *)old[x].offset);
665 }
666
667 if (local->nb_blocks > 1) {
668
669 local->block = g_malloc0(sizeof(RDMALocalBlock) *
670 (local->nb_blocks - 1));
671
672 if (block->index) {
673 memcpy(local->block, old, sizeof(RDMALocalBlock) * block->index);
674 }
675
676 if (block->index < (local->nb_blocks - 1)) {
677 memcpy(local->block + block->index, old + (block->index + 1),
678 sizeof(RDMALocalBlock) *
679 (local->nb_blocks - (block->index + 1)));
680 }
681 } else {
682 assert(block == local->block);
683 local->block = NULL;
684 }
685
686 DDPRINTF("Deleted Block: %d, addr: %" PRIu64 ", offset: %" PRIu64
687 " length: %" PRIu64 " end: %" PRIu64 " bits %" PRIu64 " chunks %d\n",
688 local->nb_blocks, (uint64_t) block->local_host_addr, block->offset,
689 block->length, (uint64_t) (block->local_host_addr + block->length),
690 BITS_TO_LONGS(block->nb_chunks) *
691 sizeof(unsigned long) * 8, block->nb_chunks);
692
693 g_free(old);
694
695 local->nb_blocks--;
696
697 if (local->nb_blocks) {
698 for (x = 0; x < local->nb_blocks; x++) {
699 g_hash_table_insert(rdma->blockmap, (void *)local->block[x].offset,
700 &local->block[x]);
701 }
702 }
703
704 return 0;
705 }
706
707 /*
708 * Put in the log file which RDMA device was opened and the details
709 * associated with that device.
710 */
711 static void qemu_rdma_dump_id(const char *who, struct ibv_context *verbs)
712 {
713 struct ibv_port_attr port;
714
715 if (ibv_query_port(verbs, 1, &port)) {
716 fprintf(stderr, "FAILED TO QUERY PORT INFORMATION!\n");
717 return;
718 }
719
720 printf("%s RDMA Device opened: kernel name %s "
721 "uverbs device name %s, "
722 "infiniband_verbs class device path %s, "
723 "infiniband class device path %s, "
724 "transport: (%d) %s\n",
725 who,
726 verbs->device->name,
727 verbs->device->dev_name,
728 verbs->device->dev_path,
729 verbs->device->ibdev_path,
730 port.link_layer,
731 (port.link_layer == IBV_LINK_LAYER_INFINIBAND) ? "Infiniband" :
732 ((port.link_layer == IBV_LINK_LAYER_ETHERNET)
733 ? "Ethernet" : "Unknown"));
734 }
735
736 /*
737 * Put in the log file the RDMA gid addressing information,
738 * useful for folks who have trouble understanding the
739 * RDMA device hierarchy in the kernel.
740 */
741 static void qemu_rdma_dump_gid(const char *who, struct rdma_cm_id *id)
742 {
743 char sgid[33];
744 char dgid[33];
745 inet_ntop(AF_INET6, &id->route.addr.addr.ibaddr.sgid, sgid, sizeof sgid);
746 inet_ntop(AF_INET6, &id->route.addr.addr.ibaddr.dgid, dgid, sizeof dgid);
747 DPRINTF("%s Source GID: %s, Dest GID: %s\n", who, sgid, dgid);
748 }
749
750 /*
751 * As of now, IPv6 over RoCE / iWARP is not supported by linux.
752 * We will try the next addrinfo struct, and fail if there are
753 * no other valid addresses to bind against.
754 *
755 * If user is listening on '[::]', then we will not have a opened a device
756 * yet and have no way of verifying if the device is RoCE or not.
757 *
758 * In this case, the source VM will throw an error for ALL types of
759 * connections (both IPv4 and IPv6) if the destination machine does not have
760 * a regular infiniband network available for use.
761 *
762 * The only way to guarantee that an error is thrown for broken kernels is
763 * for the management software to choose a *specific* interface at bind time
764 * and validate what time of hardware it is.
765 *
766 * Unfortunately, this puts the user in a fix:
767 *
768 * If the source VM connects with an IPv4 address without knowing that the
769 * destination has bound to '[::]' the migration will unconditionally fail
770 * unless the management software is explicitly listening on the the IPv4
771 * address while using a RoCE-based device.
772 *
773 * If the source VM connects with an IPv6 address, then we're OK because we can
774 * throw an error on the source (and similarly on the destination).
775 *
776 * But in mixed environments, this will be broken for a while until it is fixed
777 * inside linux.
778 *
779 * We do provide a *tiny* bit of help in this function: We can list all of the
780 * devices in the system and check to see if all the devices are RoCE or
781 * Infiniband.
782 *
783 * If we detect that we have a *pure* RoCE environment, then we can safely
784 * thrown an error even if the management software has specified '[::]' as the
785 * bind address.
786 *
787 * However, if there is are multiple hetergeneous devices, then we cannot make
788 * this assumption and the user just has to be sure they know what they are
789 * doing.
790 *
791 * Patches are being reviewed on linux-rdma.
792 */
793 static int qemu_rdma_broken_ipv6_kernel(Error **errp, struct ibv_context *verbs)
794 {
795 struct ibv_port_attr port_attr;
796
797 /* This bug only exists in linux, to our knowledge. */
798 #ifdef CONFIG_LINUX
799
800 /*
801 * Verbs are only NULL if management has bound to '[::]'.
802 *
803 * Let's iterate through all the devices and see if there any pure IB
804 * devices (non-ethernet).
805 *
806 * If not, then we can safely proceed with the migration.
807 * Otherwise, there are no guarantees until the bug is fixed in linux.
808 */
809 if (!verbs) {
810 int num_devices, x;
811 struct ibv_device ** dev_list = ibv_get_device_list(&num_devices);
812 bool roce_found = false;
813 bool ib_found = false;
814
815 for (x = 0; x < num_devices; x++) {
816 verbs = ibv_open_device(dev_list[x]);
817
818 if (ibv_query_port(verbs, 1, &port_attr)) {
819 ibv_close_device(verbs);
820 ERROR(errp, "Could not query initial IB port");
821 return -EINVAL;
822 }
823
824 if (port_attr.link_layer == IBV_LINK_LAYER_INFINIBAND) {
825 ib_found = true;
826 } else if (port_attr.link_layer == IBV_LINK_LAYER_ETHERNET) {
827 roce_found = true;
828 }
829
830 ibv_close_device(verbs);
831
832 }
833
834 if (roce_found) {
835 if (ib_found) {
836 fprintf(stderr, "WARN: migrations may fail:"
837 " IPv6 over RoCE / iWARP in linux"
838 " is broken. But since you appear to have a"
839 " mixed RoCE / IB environment, be sure to only"
840 " migrate over the IB fabric until the kernel "
841 " fixes the bug.\n");
842 } else {
843 ERROR(errp, "You only have RoCE / iWARP devices in your systems"
844 " and your management software has specified '[::]'"
845 ", but IPv6 over RoCE / iWARP is not supported in Linux.");
846 return -ENONET;
847 }
848 }
849
850 return 0;
851 }
852
853 /*
854 * If we have a verbs context, that means that some other than '[::]' was
855 * used by the management software for binding. In which case we can actually
856 * warn the user about a potential broken kernel;
857 */
858
859 /* IB ports start with 1, not 0 */
860 if (ibv_query_port(verbs, 1, &port_attr)) {
861 ERROR(errp, "Could not query initial IB port");
862 return -EINVAL;
863 }
864
865 if (port_attr.link_layer == IBV_LINK_LAYER_ETHERNET) {
866 ERROR(errp, "Linux kernel's RoCE / iWARP does not support IPv6 "
867 "(but patches on linux-rdma in progress)");
868 return -ENONET;
869 }
870
871 #endif
872
873 return 0;
874 }
875
876 /*
877 * Figure out which RDMA device corresponds to the requested IP hostname
878 * Also create the initial connection manager identifiers for opening
879 * the connection.
880 */
881 static int qemu_rdma_resolve_host(RDMAContext *rdma, Error **errp)
882 {
883 int ret;
884 struct rdma_addrinfo *res;
885 char port_str[16];
886 struct rdma_cm_event *cm_event;
887 char ip[40] = "unknown";
888 struct rdma_addrinfo *e;
889
890 if (rdma->host == NULL || !strcmp(rdma->host, "")) {
891 ERROR(errp, "RDMA hostname has not been set");
892 return -EINVAL;
893 }
894
895 /* create CM channel */
896 rdma->channel = rdma_create_event_channel();
897 if (!rdma->channel) {
898 ERROR(errp, "could not create CM channel");
899 return -EINVAL;
900 }
901
902 /* create CM id */
903 ret = rdma_create_id(rdma->channel, &rdma->cm_id, NULL, RDMA_PS_TCP);
904 if (ret) {
905 ERROR(errp, "could not create channel id");
906 goto err_resolve_create_id;
907 }
908
909 snprintf(port_str, 16, "%d", rdma->port);
910 port_str[15] = '\0';
911
912 ret = rdma_getaddrinfo(rdma->host, port_str, NULL, &res);
913 if (ret < 0) {
914 ERROR(errp, "could not rdma_getaddrinfo address %s", rdma->host);
915 goto err_resolve_get_addr;
916 }
917
918 for (e = res; e != NULL; e = e->ai_next) {
919 inet_ntop(e->ai_family,
920 &((struct sockaddr_in *) e->ai_dst_addr)->sin_addr, ip, sizeof ip);
921 DPRINTF("Trying %s => %s\n", rdma->host, ip);
922
923 ret = rdma_resolve_addr(rdma->cm_id, NULL, e->ai_dst_addr,
924 RDMA_RESOLVE_TIMEOUT_MS);
925 if (!ret) {
926 if (e->ai_family == AF_INET6) {
927 ret = qemu_rdma_broken_ipv6_kernel(errp, rdma->cm_id->verbs);
928 if (ret) {
929 continue;
930 }
931 }
932 goto route;
933 }
934 }
935
936 ERROR(errp, "could not resolve address %s", rdma->host);
937 goto err_resolve_get_addr;
938
939 route:
940 qemu_rdma_dump_gid("source_resolve_addr", rdma->cm_id);
941
942 ret = rdma_get_cm_event(rdma->channel, &cm_event);
943 if (ret) {
944 ERROR(errp, "could not perform event_addr_resolved");
945 goto err_resolve_get_addr;
946 }
947
948 if (cm_event->event != RDMA_CM_EVENT_ADDR_RESOLVED) {
949 ERROR(errp, "result not equal to event_addr_resolved %s",
950 rdma_event_str(cm_event->event));
951 perror("rdma_resolve_addr");
952 ret = -EINVAL;
953 goto err_resolve_get_addr;
954 }
955 rdma_ack_cm_event(cm_event);
956
957 /* resolve route */
958 ret = rdma_resolve_route(rdma->cm_id, RDMA_RESOLVE_TIMEOUT_MS);
959 if (ret) {
960 ERROR(errp, "could not resolve rdma route");
961 goto err_resolve_get_addr;
962 }
963
964 ret = rdma_get_cm_event(rdma->channel, &cm_event);
965 if (ret) {
966 ERROR(errp, "could not perform event_route_resolved");
967 goto err_resolve_get_addr;
968 }
969 if (cm_event->event != RDMA_CM_EVENT_ROUTE_RESOLVED) {
970 ERROR(errp, "result not equal to event_route_resolved: %s",
971 rdma_event_str(cm_event->event));
972 rdma_ack_cm_event(cm_event);
973 ret = -EINVAL;
974 goto err_resolve_get_addr;
975 }
976 rdma_ack_cm_event(cm_event);
977 rdma->verbs = rdma->cm_id->verbs;
978 qemu_rdma_dump_id("source_resolve_host", rdma->cm_id->verbs);
979 qemu_rdma_dump_gid("source_resolve_host", rdma->cm_id);
980 return 0;
981
982 err_resolve_get_addr:
983 rdma_destroy_id(rdma->cm_id);
984 rdma->cm_id = NULL;
985 err_resolve_create_id:
986 rdma_destroy_event_channel(rdma->channel);
987 rdma->channel = NULL;
988 return ret;
989 }
990
991 /*
992 * Create protection domain and completion queues
993 */
994 static int qemu_rdma_alloc_pd_cq(RDMAContext *rdma)
995 {
996 /* allocate pd */
997 rdma->pd = ibv_alloc_pd(rdma->verbs);
998 if (!rdma->pd) {
999 fprintf(stderr, "failed to allocate protection domain\n");
1000 return -1;
1001 }
1002
1003 /* create completion channel */
1004 rdma->comp_channel = ibv_create_comp_channel(rdma->verbs);
1005 if (!rdma->comp_channel) {
1006 fprintf(stderr, "failed to allocate completion channel\n");
1007 goto err_alloc_pd_cq;
1008 }
1009
1010 /*
1011 * Completion queue can be filled by both read and write work requests,
1012 * so must reflect the sum of both possible queue sizes.
1013 */
1014 rdma->cq = ibv_create_cq(rdma->verbs, (RDMA_SIGNALED_SEND_MAX * 3),
1015 NULL, rdma->comp_channel, 0);
1016 if (!rdma->cq) {
1017 fprintf(stderr, "failed to allocate completion queue\n");
1018 goto err_alloc_pd_cq;
1019 }
1020
1021 return 0;
1022
1023 err_alloc_pd_cq:
1024 if (rdma->pd) {
1025 ibv_dealloc_pd(rdma->pd);
1026 }
1027 if (rdma->comp_channel) {
1028 ibv_destroy_comp_channel(rdma->comp_channel);
1029 }
1030 rdma->pd = NULL;
1031 rdma->comp_channel = NULL;
1032 return -1;
1033
1034 }
1035
1036 /*
1037 * Create queue pairs.
1038 */
1039 static int qemu_rdma_alloc_qp(RDMAContext *rdma)
1040 {
1041 struct ibv_qp_init_attr attr = { 0 };
1042 int ret;
1043
1044 attr.cap.max_send_wr = RDMA_SIGNALED_SEND_MAX;
1045 attr.cap.max_recv_wr = 3;
1046 attr.cap.max_send_sge = 1;
1047 attr.cap.max_recv_sge = 1;
1048 attr.send_cq = rdma->cq;
1049 attr.recv_cq = rdma->cq;
1050 attr.qp_type = IBV_QPT_RC;
1051
1052 ret = rdma_create_qp(rdma->cm_id, rdma->pd, &attr);
1053 if (ret) {
1054 return -1;
1055 }
1056
1057 rdma->qp = rdma->cm_id->qp;
1058 return 0;
1059 }
1060
1061 static int qemu_rdma_reg_whole_ram_blocks(RDMAContext *rdma)
1062 {
1063 int i;
1064 RDMALocalBlocks *local = &rdma->local_ram_blocks;
1065
1066 for (i = 0; i < local->nb_blocks; i++) {
1067 local->block[i].mr =
1068 ibv_reg_mr(rdma->pd,
1069 local->block[i].local_host_addr,
1070 local->block[i].length,
1071 IBV_ACCESS_LOCAL_WRITE |
1072 IBV_ACCESS_REMOTE_WRITE
1073 );
1074 if (!local->block[i].mr) {
1075 perror("Failed to register local dest ram block!\n");
1076 break;
1077 }
1078 rdma->total_registrations++;
1079 }
1080
1081 if (i >= local->nb_blocks) {
1082 return 0;
1083 }
1084
1085 for (i--; i >= 0; i--) {
1086 ibv_dereg_mr(local->block[i].mr);
1087 rdma->total_registrations--;
1088 }
1089
1090 return -1;
1091
1092 }
1093
1094 /*
1095 * Find the ram block that corresponds to the page requested to be
1096 * transmitted by QEMU.
1097 *
1098 * Once the block is found, also identify which 'chunk' within that
1099 * block that the page belongs to.
1100 *
1101 * This search cannot fail or the migration will fail.
1102 */
1103 static int qemu_rdma_search_ram_block(RDMAContext *rdma,
1104 uint64_t block_offset,
1105 uint64_t offset,
1106 uint64_t length,
1107 uint64_t *block_index,
1108 uint64_t *chunk_index)
1109 {
1110 uint64_t current_addr = block_offset + offset;
1111 RDMALocalBlock *block = g_hash_table_lookup(rdma->blockmap,
1112 (void *) block_offset);
1113 assert(block);
1114 assert(current_addr >= block->offset);
1115 assert((current_addr + length) <= (block->offset + block->length));
1116
1117 *block_index = block->index;
1118 *chunk_index = ram_chunk_index(block->local_host_addr,
1119 block->local_host_addr + (current_addr - block->offset));
1120
1121 return 0;
1122 }
1123
1124 /*
1125 * Register a chunk with IB. If the chunk was already registered
1126 * previously, then skip.
1127 *
1128 * Also return the keys associated with the registration needed
1129 * to perform the actual RDMA operation.
1130 */
1131 static int qemu_rdma_register_and_get_keys(RDMAContext *rdma,
1132 RDMALocalBlock *block, uint8_t *host_addr,
1133 uint32_t *lkey, uint32_t *rkey, int chunk,
1134 uint8_t *chunk_start, uint8_t *chunk_end)
1135 {
1136 if (block->mr) {
1137 if (lkey) {
1138 *lkey = block->mr->lkey;
1139 }
1140 if (rkey) {
1141 *rkey = block->mr->rkey;
1142 }
1143 return 0;
1144 }
1145
1146 /* allocate memory to store chunk MRs */
1147 if (!block->pmr) {
1148 block->pmr = g_malloc0(block->nb_chunks * sizeof(struct ibv_mr *));
1149 if (!block->pmr) {
1150 return -1;
1151 }
1152 }
1153
1154 /*
1155 * If 'rkey', then we're the destination, so grant access to the source.
1156 *
1157 * If 'lkey', then we're the source VM, so grant access only to ourselves.
1158 */
1159 if (!block->pmr[chunk]) {
1160 uint64_t len = chunk_end - chunk_start;
1161
1162 DDPRINTF("Registering %" PRIu64 " bytes @ %p\n",
1163 len, chunk_start);
1164
1165 block->pmr[chunk] = ibv_reg_mr(rdma->pd,
1166 chunk_start, len,
1167 (rkey ? (IBV_ACCESS_LOCAL_WRITE |
1168 IBV_ACCESS_REMOTE_WRITE) : 0));
1169
1170 if (!block->pmr[chunk]) {
1171 perror("Failed to register chunk!");
1172 fprintf(stderr, "Chunk details: block: %d chunk index %d"
1173 " start %" PRIu64 " end %" PRIu64 " host %" PRIu64
1174 " local %" PRIu64 " registrations: %d\n",
1175 block->index, chunk, (uint64_t) chunk_start,
1176 (uint64_t) chunk_end, (uint64_t) host_addr,
1177 (uint64_t) block->local_host_addr,
1178 rdma->total_registrations);
1179 return -1;
1180 }
1181 rdma->total_registrations++;
1182 }
1183
1184 if (lkey) {
1185 *lkey = block->pmr[chunk]->lkey;
1186 }
1187 if (rkey) {
1188 *rkey = block->pmr[chunk]->rkey;
1189 }
1190 return 0;
1191 }
1192
1193 /*
1194 * Register (at connection time) the memory used for control
1195 * channel messages.
1196 */
1197 static int qemu_rdma_reg_control(RDMAContext *rdma, int idx)
1198 {
1199 rdma->wr_data[idx].control_mr = ibv_reg_mr(rdma->pd,
1200 rdma->wr_data[idx].control, RDMA_CONTROL_MAX_BUFFER,
1201 IBV_ACCESS_LOCAL_WRITE | IBV_ACCESS_REMOTE_WRITE);
1202 if (rdma->wr_data[idx].control_mr) {
1203 rdma->total_registrations++;
1204 return 0;
1205 }
1206 fprintf(stderr, "qemu_rdma_reg_control failed!\n");
1207 return -1;
1208 }
1209
1210 const char *print_wrid(int wrid)
1211 {
1212 if (wrid >= RDMA_WRID_RECV_CONTROL) {
1213 return wrid_desc[RDMA_WRID_RECV_CONTROL];
1214 }
1215 return wrid_desc[wrid];
1216 }
1217
1218 /*
1219 * RDMA requires memory registration (mlock/pinning), but this is not good for
1220 * overcommitment.
1221 *
1222 * In preparation for the future where LRU information or workload-specific
1223 * writable writable working set memory access behavior is available to QEMU
1224 * it would be nice to have in place the ability to UN-register/UN-pin
1225 * particular memory regions from the RDMA hardware when it is determine that
1226 * those regions of memory will likely not be accessed again in the near future.
1227 *
1228 * While we do not yet have such information right now, the following
1229 * compile-time option allows us to perform a non-optimized version of this
1230 * behavior.
1231 *
1232 * By uncommenting this option, you will cause *all* RDMA transfers to be
1233 * unregistered immediately after the transfer completes on both sides of the
1234 * connection. This has no effect in 'rdma-pin-all' mode, only regular mode.
1235 *
1236 * This will have a terrible impact on migration performance, so until future
1237 * workload information or LRU information is available, do not attempt to use
1238 * this feature except for basic testing.
1239 */
1240 //#define RDMA_UNREGISTRATION_EXAMPLE
1241
1242 /*
1243 * Perform a non-optimized memory unregistration after every transfer
1244 * for demonsration purposes, only if pin-all is not requested.
1245 *
1246 * Potential optimizations:
1247 * 1. Start a new thread to run this function continuously
1248 - for bit clearing
1249 - and for receipt of unregister messages
1250 * 2. Use an LRU.
1251 * 3. Use workload hints.
1252 */
1253 static int qemu_rdma_unregister_waiting(RDMAContext *rdma)
1254 {
1255 while (rdma->unregistrations[rdma->unregister_current]) {
1256 int ret;
1257 uint64_t wr_id = rdma->unregistrations[rdma->unregister_current];
1258 uint64_t chunk =
1259 (wr_id & RDMA_WRID_CHUNK_MASK) >> RDMA_WRID_CHUNK_SHIFT;
1260 uint64_t index =
1261 (wr_id & RDMA_WRID_BLOCK_MASK) >> RDMA_WRID_BLOCK_SHIFT;
1262 RDMALocalBlock *block =
1263 &(rdma->local_ram_blocks.block[index]);
1264 RDMARegister reg = { .current_index = index };
1265 RDMAControlHeader resp = { .type = RDMA_CONTROL_UNREGISTER_FINISHED,
1266 };
1267 RDMAControlHeader head = { .len = sizeof(RDMARegister),
1268 .type = RDMA_CONTROL_UNREGISTER_REQUEST,
1269 .repeat = 1,
1270 };
1271
1272 DDPRINTF("Processing unregister for chunk: %" PRIu64
1273 " at position %d\n", chunk, rdma->unregister_current);
1274
1275 rdma->unregistrations[rdma->unregister_current] = 0;
1276 rdma->unregister_current++;
1277
1278 if (rdma->unregister_current == RDMA_SIGNALED_SEND_MAX) {
1279 rdma->unregister_current = 0;
1280 }
1281
1282
1283 /*
1284 * Unregistration is speculative (because migration is single-threaded
1285 * and we cannot break the protocol's inifinband message ordering).
1286 * Thus, if the memory is currently being used for transmission,
1287 * then abort the attempt to unregister and try again
1288 * later the next time a completion is received for this memory.
1289 */
1290 clear_bit(chunk, block->unregister_bitmap);
1291
1292 if (test_bit(chunk, block->transit_bitmap)) {
1293 DDPRINTF("Cannot unregister inflight chunk: %" PRIu64 "\n", chunk);
1294 continue;
1295 }
1296
1297 DDPRINTF("Sending unregister for chunk: %" PRIu64 "\n", chunk);
1298
1299 ret = ibv_dereg_mr(block->pmr[chunk]);
1300 block->pmr[chunk] = NULL;
1301 block->remote_keys[chunk] = 0;
1302
1303 if (ret != 0) {
1304 perror("unregistration chunk failed");
1305 return -ret;
1306 }
1307 rdma->total_registrations--;
1308
1309 reg.key.chunk = chunk;
1310 register_to_network(&reg);
1311 ret = qemu_rdma_exchange_send(rdma, &head, (uint8_t *) &reg,
1312 &resp, NULL, NULL);
1313 if (ret < 0) {
1314 return ret;
1315 }
1316
1317 DDPRINTF("Unregister for chunk: %" PRIu64 " complete.\n", chunk);
1318 }
1319
1320 return 0;
1321 }
1322
1323 static uint64_t qemu_rdma_make_wrid(uint64_t wr_id, uint64_t index,
1324 uint64_t chunk)
1325 {
1326 uint64_t result = wr_id & RDMA_WRID_TYPE_MASK;
1327
1328 result |= (index << RDMA_WRID_BLOCK_SHIFT);
1329 result |= (chunk << RDMA_WRID_CHUNK_SHIFT);
1330
1331 return result;
1332 }
1333
1334 /*
1335 * Set bit for unregistration in the next iteration.
1336 * We cannot transmit right here, but will unpin later.
1337 */
1338 static void qemu_rdma_signal_unregister(RDMAContext *rdma, uint64_t index,
1339 uint64_t chunk, uint64_t wr_id)
1340 {
1341 if (rdma->unregistrations[rdma->unregister_next] != 0) {
1342 fprintf(stderr, "rdma migration: queue is full!\n");
1343 } else {
1344 RDMALocalBlock *block = &(rdma->local_ram_blocks.block[index]);
1345
1346 if (!test_and_set_bit(chunk, block->unregister_bitmap)) {
1347 DDPRINTF("Appending unregister chunk %" PRIu64
1348 " at position %d\n", chunk, rdma->unregister_next);
1349
1350 rdma->unregistrations[rdma->unregister_next++] =
1351 qemu_rdma_make_wrid(wr_id, index, chunk);
1352
1353 if (rdma->unregister_next == RDMA_SIGNALED_SEND_MAX) {
1354 rdma->unregister_next = 0;
1355 }
1356 } else {
1357 DDPRINTF("Unregister chunk %" PRIu64 " already in queue.\n",
1358 chunk);
1359 }
1360 }
1361 }
1362
1363 /*
1364 * Consult the connection manager to see a work request
1365 * (of any kind) has completed.
1366 * Return the work request ID that completed.
1367 */
1368 static uint64_t qemu_rdma_poll(RDMAContext *rdma, uint64_t *wr_id_out,
1369 uint32_t *byte_len)
1370 {
1371 int ret;
1372 struct ibv_wc wc;
1373 uint64_t wr_id;
1374
1375 ret = ibv_poll_cq(rdma->cq, 1, &wc);
1376
1377 if (!ret) {
1378 *wr_id_out = RDMA_WRID_NONE;
1379 return 0;
1380 }
1381
1382 if (ret < 0) {
1383 fprintf(stderr, "ibv_poll_cq return %d!\n", ret);
1384 return ret;
1385 }
1386
1387 wr_id = wc.wr_id & RDMA_WRID_TYPE_MASK;
1388
1389 if (wc.status != IBV_WC_SUCCESS) {
1390 fprintf(stderr, "ibv_poll_cq wc.status=%d %s!\n",
1391 wc.status, ibv_wc_status_str(wc.status));
1392 fprintf(stderr, "ibv_poll_cq wrid=%s!\n", wrid_desc[wr_id]);
1393
1394 return -1;
1395 }
1396
1397 if (rdma->control_ready_expected &&
1398 (wr_id >= RDMA_WRID_RECV_CONTROL)) {
1399 DDDPRINTF("completion %s #%" PRId64 " received (%" PRId64 ")"
1400 " left %d\n", wrid_desc[RDMA_WRID_RECV_CONTROL],
1401 wr_id - RDMA_WRID_RECV_CONTROL, wr_id, rdma->nb_sent);
1402 rdma->control_ready_expected = 0;
1403 }
1404
1405 if (wr_id == RDMA_WRID_RDMA_WRITE) {
1406 uint64_t chunk =
1407 (wc.wr_id & RDMA_WRID_CHUNK_MASK) >> RDMA_WRID_CHUNK_SHIFT;
1408 uint64_t index =
1409 (wc.wr_id & RDMA_WRID_BLOCK_MASK) >> RDMA_WRID_BLOCK_SHIFT;
1410 RDMALocalBlock *block = &(rdma->local_ram_blocks.block[index]);
1411
1412 DDDPRINTF("completions %s (%" PRId64 ") left %d, "
1413 "block %" PRIu64 ", chunk: %" PRIu64 " %p %p\n",
1414 print_wrid(wr_id), wr_id, rdma->nb_sent, index, chunk,
1415 block->local_host_addr, (void *)block->remote_host_addr);
1416
1417 clear_bit(chunk, block->transit_bitmap);
1418
1419 if (rdma->nb_sent > 0) {
1420 rdma->nb_sent--;
1421 }
1422
1423 if (!rdma->pin_all) {
1424 /*
1425 * FYI: If one wanted to signal a specific chunk to be unregistered
1426 * using LRU or workload-specific information, this is the function
1427 * you would call to do so. That chunk would then get asynchronously
1428 * unregistered later.
1429 */
1430 #ifdef RDMA_UNREGISTRATION_EXAMPLE
1431 qemu_rdma_signal_unregister(rdma, index, chunk, wc.wr_id);
1432 #endif
1433 }
1434 } else {
1435 DDDPRINTF("other completion %s (%" PRId64 ") received left %d\n",
1436 print_wrid(wr_id), wr_id, rdma->nb_sent);
1437 }
1438
1439 *wr_id_out = wc.wr_id;
1440 if (byte_len) {
1441 *byte_len = wc.byte_len;
1442 }
1443
1444 return 0;
1445 }
1446
1447 /*
1448 * Block until the next work request has completed.
1449 *
1450 * First poll to see if a work request has already completed,
1451 * otherwise block.
1452 *
1453 * If we encounter completed work requests for IDs other than
1454 * the one we're interested in, then that's generally an error.
1455 *
1456 * The only exception is actual RDMA Write completions. These
1457 * completions only need to be recorded, but do not actually
1458 * need further processing.
1459 */
1460 static int qemu_rdma_block_for_wrid(RDMAContext *rdma, int wrid_requested,
1461 uint32_t *byte_len)
1462 {
1463 int num_cq_events = 0, ret = 0;
1464 struct ibv_cq *cq;
1465 void *cq_ctx;
1466 uint64_t wr_id = RDMA_WRID_NONE, wr_id_in;
1467
1468 if (ibv_req_notify_cq(rdma->cq, 0)) {
1469 return -1;
1470 }
1471 /* poll cq first */
1472 while (wr_id != wrid_requested) {
1473 ret = qemu_rdma_poll(rdma, &wr_id_in, byte_len);
1474 if (ret < 0) {
1475 return ret;
1476 }
1477
1478 wr_id = wr_id_in & RDMA_WRID_TYPE_MASK;
1479
1480 if (wr_id == RDMA_WRID_NONE) {
1481 break;
1482 }
1483 if (wr_id != wrid_requested) {
1484 DDDPRINTF("A Wanted wrid %s (%d) but got %s (%" PRIu64 ")\n",
1485 print_wrid(wrid_requested),
1486 wrid_requested, print_wrid(wr_id), wr_id);
1487 }
1488 }
1489
1490 if (wr_id == wrid_requested) {
1491 return 0;
1492 }
1493
1494 while (1) {
1495 /*
1496 * Coroutine doesn't start until process_incoming_migration()
1497 * so don't yield unless we know we're running inside of a coroutine.
1498 */
1499 if (rdma->migration_started_on_destination) {
1500 yield_until_fd_readable(rdma->comp_channel->fd);
1501 }
1502
1503 if (ibv_get_cq_event(rdma->comp_channel, &cq, &cq_ctx)) {
1504 perror("ibv_get_cq_event");
1505 goto err_block_for_wrid;
1506 }
1507
1508 num_cq_events++;
1509
1510 if (ibv_req_notify_cq(cq, 0)) {
1511 goto err_block_for_wrid;
1512 }
1513
1514 while (wr_id != wrid_requested) {
1515 ret = qemu_rdma_poll(rdma, &wr_id_in, byte_len);
1516 if (ret < 0) {
1517 goto err_block_for_wrid;
1518 }
1519
1520 wr_id = wr_id_in & RDMA_WRID_TYPE_MASK;
1521
1522 if (wr_id == RDMA_WRID_NONE) {
1523 break;
1524 }
1525 if (wr_id != wrid_requested) {
1526 DDDPRINTF("B Wanted wrid %s (%d) but got %s (%" PRIu64 ")\n",
1527 print_wrid(wrid_requested), wrid_requested,
1528 print_wrid(wr_id), wr_id);
1529 }
1530 }
1531
1532 if (wr_id == wrid_requested) {
1533 goto success_block_for_wrid;
1534 }
1535 }
1536
1537 success_block_for_wrid:
1538 if (num_cq_events) {
1539 ibv_ack_cq_events(cq, num_cq_events);
1540 }
1541 return 0;
1542
1543 err_block_for_wrid:
1544 if (num_cq_events) {
1545 ibv_ack_cq_events(cq, num_cq_events);
1546 }
1547 return ret;
1548 }
1549
1550 /*
1551 * Post a SEND message work request for the control channel
1552 * containing some data and block until the post completes.
1553 */
1554 static int qemu_rdma_post_send_control(RDMAContext *rdma, uint8_t *buf,
1555 RDMAControlHeader *head)
1556 {
1557 int ret = 0;
1558 RDMAWorkRequestData *wr = &rdma->wr_data[RDMA_WRID_CONTROL];
1559 struct ibv_send_wr *bad_wr;
1560 struct ibv_sge sge = {
1561 .addr = (uint64_t)(wr->control),
1562 .length = head->len + sizeof(RDMAControlHeader),
1563 .lkey = wr->control_mr->lkey,
1564 };
1565 struct ibv_send_wr send_wr = {
1566 .wr_id = RDMA_WRID_SEND_CONTROL,
1567 .opcode = IBV_WR_SEND,
1568 .send_flags = IBV_SEND_SIGNALED,
1569 .sg_list = &sge,
1570 .num_sge = 1,
1571 };
1572
1573 DDDPRINTF("CONTROL: sending %s..\n", control_desc[head->type]);
1574
1575 /*
1576 * We don't actually need to do a memcpy() in here if we used
1577 * the "sge" properly, but since we're only sending control messages
1578 * (not RAM in a performance-critical path), then its OK for now.
1579 *
1580 * The copy makes the RDMAControlHeader simpler to manipulate
1581 * for the time being.
1582 */
1583 assert(head->len <= RDMA_CONTROL_MAX_BUFFER - sizeof(*head));
1584 memcpy(wr->control, head, sizeof(RDMAControlHeader));
1585 control_to_network((void *) wr->control);
1586
1587 if (buf) {
1588 memcpy(wr->control + sizeof(RDMAControlHeader), buf, head->len);
1589 }
1590
1591
1592 if (ibv_post_send(rdma->qp, &send_wr, &bad_wr)) {
1593 return -1;
1594 }
1595
1596 if (ret < 0) {
1597 fprintf(stderr, "Failed to use post IB SEND for control!\n");
1598 return ret;
1599 }
1600
1601 ret = qemu_rdma_block_for_wrid(rdma, RDMA_WRID_SEND_CONTROL, NULL);
1602 if (ret < 0) {
1603 fprintf(stderr, "rdma migration: send polling control error!\n");
1604 }
1605
1606 return ret;
1607 }
1608
1609 /*
1610 * Post a RECV work request in anticipation of some future receipt
1611 * of data on the control channel.
1612 */
1613 static int qemu_rdma_post_recv_control(RDMAContext *rdma, int idx)
1614 {
1615 struct ibv_recv_wr *bad_wr;
1616 struct ibv_sge sge = {
1617 .addr = (uint64_t)(rdma->wr_data[idx].control),
1618 .length = RDMA_CONTROL_MAX_BUFFER,
1619 .lkey = rdma->wr_data[idx].control_mr->lkey,
1620 };
1621
1622 struct ibv_recv_wr recv_wr = {
1623 .wr_id = RDMA_WRID_RECV_CONTROL + idx,
1624 .sg_list = &sge,
1625 .num_sge = 1,
1626 };
1627
1628
1629 if (ibv_post_recv(rdma->qp, &recv_wr, &bad_wr)) {
1630 return -1;
1631 }
1632
1633 return 0;
1634 }
1635
1636 /*
1637 * Block and wait for a RECV control channel message to arrive.
1638 */
1639 static int qemu_rdma_exchange_get_response(RDMAContext *rdma,
1640 RDMAControlHeader *head, int expecting, int idx)
1641 {
1642 uint32_t byte_len;
1643 int ret = qemu_rdma_block_for_wrid(rdma, RDMA_WRID_RECV_CONTROL + idx,
1644 &byte_len);
1645
1646 if (ret < 0) {
1647 fprintf(stderr, "rdma migration: recv polling control error!\n");
1648 return ret;
1649 }
1650
1651 network_to_control((void *) rdma->wr_data[idx].control);
1652 memcpy(head, rdma->wr_data[idx].control, sizeof(RDMAControlHeader));
1653
1654 DDDPRINTF("CONTROL: %s receiving...\n", control_desc[expecting]);
1655
1656 if (expecting == RDMA_CONTROL_NONE) {
1657 DDDPRINTF("Surprise: got %s (%d)\n",
1658 control_desc[head->type], head->type);
1659 } else if (head->type != expecting || head->type == RDMA_CONTROL_ERROR) {
1660 fprintf(stderr, "Was expecting a %s (%d) control message"
1661 ", but got: %s (%d), length: %d\n",
1662 control_desc[expecting], expecting,
1663 control_desc[head->type], head->type, head->len);
1664 return -EIO;
1665 }
1666 if (head->len > RDMA_CONTROL_MAX_BUFFER - sizeof(*head)) {
1667 fprintf(stderr, "too long length: %d\n", head->len);
1668 return -EINVAL;
1669 }
1670 if (sizeof(*head) + head->len != byte_len) {
1671 fprintf(stderr, "Malformed length: %d byte_len %d\n",
1672 head->len, byte_len);
1673 return -EINVAL;
1674 }
1675
1676 return 0;
1677 }
1678
1679 /*
1680 * When a RECV work request has completed, the work request's
1681 * buffer is pointed at the header.
1682 *
1683 * This will advance the pointer to the data portion
1684 * of the control message of the work request's buffer that
1685 * was populated after the work request finished.
1686 */
1687 static void qemu_rdma_move_header(RDMAContext *rdma, int idx,
1688 RDMAControlHeader *head)
1689 {
1690 rdma->wr_data[idx].control_len = head->len;
1691 rdma->wr_data[idx].control_curr =
1692 rdma->wr_data[idx].control + sizeof(RDMAControlHeader);
1693 }
1694
1695 /*
1696 * This is an 'atomic' high-level operation to deliver a single, unified
1697 * control-channel message.
1698 *
1699 * Additionally, if the user is expecting some kind of reply to this message,
1700 * they can request a 'resp' response message be filled in by posting an
1701 * additional work request on behalf of the user and waiting for an additional
1702 * completion.
1703 *
1704 * The extra (optional) response is used during registration to us from having
1705 * to perform an *additional* exchange of message just to provide a response by
1706 * instead piggy-backing on the acknowledgement.
1707 */
1708 static int qemu_rdma_exchange_send(RDMAContext *rdma, RDMAControlHeader *head,
1709 uint8_t *data, RDMAControlHeader *resp,
1710 int *resp_idx,
1711 int (*callback)(RDMAContext *rdma))
1712 {
1713 int ret = 0;
1714
1715 /*
1716 * Wait until the dest is ready before attempting to deliver the message
1717 * by waiting for a READY message.
1718 */
1719 if (rdma->control_ready_expected) {
1720 RDMAControlHeader resp;
1721 ret = qemu_rdma_exchange_get_response(rdma,
1722 &resp, RDMA_CONTROL_READY, RDMA_WRID_READY);
1723 if (ret < 0) {
1724 return ret;
1725 }
1726 }
1727
1728 /*
1729 * If the user is expecting a response, post a WR in anticipation of it.
1730 */
1731 if (resp) {
1732 ret = qemu_rdma_post_recv_control(rdma, RDMA_WRID_DATA);
1733 if (ret) {
1734 fprintf(stderr, "rdma migration: error posting"
1735 " extra control recv for anticipated result!");
1736 return ret;
1737 }
1738 }
1739
1740 /*
1741 * Post a WR to replace the one we just consumed for the READY message.
1742 */
1743 ret = qemu_rdma_post_recv_control(rdma, RDMA_WRID_READY);
1744 if (ret) {
1745 fprintf(stderr, "rdma migration: error posting first control recv!");
1746 return ret;
1747 }
1748
1749 /*
1750 * Deliver the control message that was requested.
1751 */
1752 ret = qemu_rdma_post_send_control(rdma, data, head);
1753
1754 if (ret < 0) {
1755 fprintf(stderr, "Failed to send control buffer!\n");
1756 return ret;
1757 }
1758
1759 /*
1760 * If we're expecting a response, block and wait for it.
1761 */
1762 if (resp) {
1763 if (callback) {
1764 DDPRINTF("Issuing callback before receiving response...\n");
1765 ret = callback(rdma);
1766 if (ret < 0) {
1767 return ret;
1768 }
1769 }
1770
1771 DDPRINTF("Waiting for response %s\n", control_desc[resp->type]);
1772 ret = qemu_rdma_exchange_get_response(rdma, resp,
1773 resp->type, RDMA_WRID_DATA);
1774
1775 if (ret < 0) {
1776 return ret;
1777 }
1778
1779 qemu_rdma_move_header(rdma, RDMA_WRID_DATA, resp);
1780 if (resp_idx) {
1781 *resp_idx = RDMA_WRID_DATA;
1782 }
1783 DDPRINTF("Response %s received.\n", control_desc[resp->type]);
1784 }
1785
1786 rdma->control_ready_expected = 1;
1787
1788 return 0;
1789 }
1790
1791 /*
1792 * This is an 'atomic' high-level operation to receive a single, unified
1793 * control-channel message.
1794 */
1795 static int qemu_rdma_exchange_recv(RDMAContext *rdma, RDMAControlHeader *head,
1796 int expecting)
1797 {
1798 RDMAControlHeader ready = {
1799 .len = 0,
1800 .type = RDMA_CONTROL_READY,
1801 .repeat = 1,
1802 };
1803 int ret;
1804
1805 /*
1806 * Inform the source that we're ready to receive a message.
1807 */
1808 ret = qemu_rdma_post_send_control(rdma, NULL, &ready);
1809
1810 if (ret < 0) {
1811 fprintf(stderr, "Failed to send control buffer!\n");
1812 return ret;
1813 }
1814
1815 /*
1816 * Block and wait for the message.
1817 */
1818 ret = qemu_rdma_exchange_get_response(rdma, head,
1819 expecting, RDMA_WRID_READY);
1820
1821 if (ret < 0) {
1822 return ret;
1823 }
1824
1825 qemu_rdma_move_header(rdma, RDMA_WRID_READY, head);
1826
1827 /*
1828 * Post a new RECV work request to replace the one we just consumed.
1829 */
1830 ret = qemu_rdma_post_recv_control(rdma, RDMA_WRID_READY);
1831 if (ret) {
1832 fprintf(stderr, "rdma migration: error posting second control recv!");
1833 return ret;
1834 }
1835
1836 return 0;
1837 }
1838
1839 /*
1840 * Write an actual chunk of memory using RDMA.
1841 *
1842 * If we're using dynamic registration on the dest-side, we have to
1843 * send a registration command first.
1844 */
1845 static int qemu_rdma_write_one(QEMUFile *f, RDMAContext *rdma,
1846 int current_index, uint64_t current_addr,
1847 uint64_t length)
1848 {
1849 struct ibv_sge sge;
1850 struct ibv_send_wr send_wr = { 0 };
1851 struct ibv_send_wr *bad_wr;
1852 int reg_result_idx, ret, count = 0;
1853 uint64_t chunk, chunks;
1854 uint8_t *chunk_start, *chunk_end;
1855 RDMALocalBlock *block = &(rdma->local_ram_blocks.block[current_index]);
1856 RDMARegister reg;
1857 RDMARegisterResult *reg_result;
1858 RDMAControlHeader resp = { .type = RDMA_CONTROL_REGISTER_RESULT };
1859 RDMAControlHeader head = { .len = sizeof(RDMARegister),
1860 .type = RDMA_CONTROL_REGISTER_REQUEST,
1861 .repeat = 1,
1862 };
1863
1864 retry:
1865 sge.addr = (uint64_t)(block->local_host_addr +
1866 (current_addr - block->offset));
1867 sge.length = length;
1868
1869 chunk = ram_chunk_index(block->local_host_addr, (uint8_t *) sge.addr);
1870 chunk_start = ram_chunk_start(block, chunk);
1871
1872 if (block->is_ram_block) {
1873 chunks = length / (1UL << RDMA_REG_CHUNK_SHIFT);
1874
1875 if (chunks && ((length % (1UL << RDMA_REG_CHUNK_SHIFT)) == 0)) {
1876 chunks--;
1877 }
1878 } else {
1879 chunks = block->length / (1UL << RDMA_REG_CHUNK_SHIFT);
1880
1881 if (chunks && ((block->length % (1UL << RDMA_REG_CHUNK_SHIFT)) == 0)) {
1882 chunks--;
1883 }
1884 }
1885
1886 DDPRINTF("Writing %" PRIu64 " chunks, (%" PRIu64 " MB)\n",
1887 chunks + 1, (chunks + 1) * (1UL << RDMA_REG_CHUNK_SHIFT) / 1024 / 1024);
1888
1889 chunk_end = ram_chunk_end(block, chunk + chunks);
1890
1891 if (!rdma->pin_all) {
1892 #ifdef RDMA_UNREGISTRATION_EXAMPLE
1893 qemu_rdma_unregister_waiting(rdma);
1894 #endif
1895 }
1896
1897 while (test_bit(chunk, block->transit_bitmap)) {
1898 (void)count;
1899 DDPRINTF("(%d) Not clobbering: block: %d chunk %" PRIu64
1900 " current %" PRIu64 " len %" PRIu64 " %d %d\n",
1901 count++, current_index, chunk,
1902 sge.addr, length, rdma->nb_sent, block->nb_chunks);
1903
1904 ret = qemu_rdma_block_for_wrid(rdma, RDMA_WRID_RDMA_WRITE, NULL);
1905
1906 if (ret < 0) {
1907 fprintf(stderr, "Failed to Wait for previous write to complete "
1908 "block %d chunk %" PRIu64
1909 " current %" PRIu64 " len %" PRIu64 " %d\n",
1910 current_index, chunk, sge.addr, length, rdma->nb_sent);
1911 return ret;
1912 }
1913 }
1914
1915 if (!rdma->pin_all || !block->is_ram_block) {
1916 if (!block->remote_keys[chunk]) {
1917 /*
1918 * This chunk has not yet been registered, so first check to see
1919 * if the entire chunk is zero. If so, tell the other size to
1920 * memset() + madvise() the entire chunk without RDMA.
1921 */
1922
1923 if (can_use_buffer_find_nonzero_offset((void *)sge.addr, length)
1924 && buffer_find_nonzero_offset((void *)sge.addr,
1925 length) == length) {
1926 RDMACompress comp = {
1927 .offset = current_addr,
1928 .value = 0,
1929 .block_idx = current_index,
1930 .length = length,
1931 };
1932
1933 head.len = sizeof(comp);
1934 head.type = RDMA_CONTROL_COMPRESS;
1935
1936 DDPRINTF("Entire chunk is zero, sending compress: %"
1937 PRIu64 " for %d "
1938 "bytes, index: %d, offset: %" PRId64 "...\n",
1939 chunk, sge.length, current_index, current_addr);
1940
1941 compress_to_network(&comp);
1942 ret = qemu_rdma_exchange_send(rdma, &head,
1943 (uint8_t *) &comp, NULL, NULL, NULL);
1944
1945 if (ret < 0) {
1946 return -EIO;
1947 }
1948
1949 acct_update_position(f, sge.length, true);
1950
1951 return 1;
1952 }
1953
1954 /*
1955 * Otherwise, tell other side to register.
1956 */
1957 reg.current_index = current_index;
1958 if (block->is_ram_block) {
1959 reg.key.current_addr = current_addr;
1960 } else {
1961 reg.key.chunk = chunk;
1962 }
1963 reg.chunks = chunks;
1964
1965 DDPRINTF("Sending registration request chunk %" PRIu64 " for %d "
1966 "bytes, index: %d, offset: %" PRId64 "...\n",
1967 chunk, sge.length, current_index, current_addr);
1968
1969 register_to_network(&reg);
1970 ret = qemu_rdma_exchange_send(rdma, &head, (uint8_t *) &reg,
1971 &resp, &reg_result_idx, NULL);
1972 if (ret < 0) {
1973 return ret;
1974 }
1975
1976 /* try to overlap this single registration with the one we sent. */
1977 if (qemu_rdma_register_and_get_keys(rdma, block,
1978 (uint8_t *) sge.addr,
1979 &sge.lkey, NULL, chunk,
1980 chunk_start, chunk_end)) {
1981 fprintf(stderr, "cannot get lkey!\n");
1982 return -EINVAL;
1983 }
1984
1985 reg_result = (RDMARegisterResult *)
1986 rdma->wr_data[reg_result_idx].control_curr;
1987
1988 network_to_result(reg_result);
1989
1990 DDPRINTF("Received registration result:"
1991 " my key: %x their key %x, chunk %" PRIu64 "\n",
1992 block->remote_keys[chunk], reg_result->rkey, chunk);
1993
1994 block->remote_keys[chunk] = reg_result->rkey;
1995 block->remote_host_addr = reg_result->host_addr;
1996 } else {
1997 /* already registered before */
1998 if (qemu_rdma_register_and_get_keys(rdma, block,
1999 (uint8_t *)sge.addr,
2000 &sge.lkey, NULL, chunk,
2001 chunk_start, chunk_end)) {
2002 fprintf(stderr, "cannot get lkey!\n");
2003 return -EINVAL;
2004 }
2005 }
2006
2007 send_wr.wr.rdma.rkey = block->remote_keys[chunk];
2008 } else {
2009 send_wr.wr.rdma.rkey = block->remote_rkey;
2010
2011 if (qemu_rdma_register_and_get_keys(rdma, block, (uint8_t *)sge.addr,
2012 &sge.lkey, NULL, chunk,
2013 chunk_start, chunk_end)) {
2014 fprintf(stderr, "cannot get lkey!\n");
2015 return -EINVAL;
2016 }
2017 }
2018
2019 /*
2020 * Encode the ram block index and chunk within this wrid.
2021 * We will use this information at the time of completion
2022 * to figure out which bitmap to check against and then which
2023 * chunk in the bitmap to look for.
2024 */
2025 send_wr.wr_id = qemu_rdma_make_wrid(RDMA_WRID_RDMA_WRITE,
2026 current_index, chunk);
2027
2028 send_wr.opcode = IBV_WR_RDMA_WRITE;
2029 send_wr.send_flags = IBV_SEND_SIGNALED;
2030 send_wr.sg_list = &sge;
2031 send_wr.num_sge = 1;
2032 send_wr.wr.rdma.remote_addr = block->remote_host_addr +
2033 (current_addr - block->offset);
2034
2035 DDDPRINTF("Posting chunk: %" PRIu64 ", addr: %lx"
2036 " remote: %lx, bytes %" PRIu32 "\n",
2037 chunk, sge.addr, send_wr.wr.rdma.remote_addr,
2038 sge.length);
2039
2040 /*
2041 * ibv_post_send() does not return negative error numbers,
2042 * per the specification they are positive - no idea why.
2043 */
2044 ret = ibv_post_send(rdma->qp, &send_wr, &bad_wr);
2045
2046 if (ret == ENOMEM) {
2047 DDPRINTF("send queue is full. wait a little....\n");
2048 ret = qemu_rdma_block_for_wrid(rdma, RDMA_WRID_RDMA_WRITE, NULL);
2049 if (ret < 0) {
2050 fprintf(stderr, "rdma migration: failed to make "
2051 "room in full send queue! %d\n", ret);
2052 return ret;
2053 }
2054
2055 goto retry;
2056
2057 } else if (ret > 0) {
2058 perror("rdma migration: post rdma write failed");
2059 return -ret;
2060 }
2061
2062 set_bit(chunk, block->transit_bitmap);
2063 acct_update_position(f, sge.length, false);
2064 rdma->total_writes++;
2065
2066 return 0;
2067 }
2068
2069 /*
2070 * Push out any unwritten RDMA operations.
2071 *
2072 * We support sending out multiple chunks at the same time.
2073 * Not all of them need to get signaled in the completion queue.
2074 */
2075 static int qemu_rdma_write_flush(QEMUFile *f, RDMAContext *rdma)
2076 {
2077 int ret;
2078
2079 if (!rdma->current_length) {
2080 return 0;
2081 }
2082
2083 ret = qemu_rdma_write_one(f, rdma,
2084 rdma->current_index, rdma->current_addr, rdma->current_length);
2085
2086 if (ret < 0) {
2087 return ret;
2088 }
2089
2090 if (ret == 0) {
2091 rdma->nb_sent++;
2092 DDDPRINTF("sent total: %d\n", rdma->nb_sent);
2093 }
2094
2095 rdma->current_length = 0;
2096 rdma->current_addr = 0;
2097
2098 return 0;
2099 }
2100
2101 static inline int qemu_rdma_buffer_mergable(RDMAContext *rdma,
2102 uint64_t offset, uint64_t len)
2103 {
2104 RDMALocalBlock *block;
2105 uint8_t *host_addr;
2106 uint8_t *chunk_end;
2107
2108 if (rdma->current_index < 0) {
2109 return 0;
2110 }
2111
2112 if (rdma->current_chunk < 0) {
2113 return 0;
2114 }
2115
2116 block = &(rdma->local_ram_blocks.block[rdma->current_index]);
2117 host_addr = block->local_host_addr + (offset - block->offset);
2118 chunk_end = ram_chunk_end(block, rdma->current_chunk);
2119
2120 if (rdma->current_length == 0) {
2121 return 0;
2122 }
2123
2124 /*
2125 * Only merge into chunk sequentially.
2126 */
2127 if (offset != (rdma->current_addr + rdma->current_length)) {
2128 return 0;
2129 }
2130
2131 if (offset < block->offset) {
2132 return 0;
2133 }
2134
2135 if ((offset + len) > (block->offset + block->length)) {
2136 return 0;
2137 }
2138
2139 if ((host_addr + len) > chunk_end) {
2140 return 0;
2141 }
2142
2143 return 1;
2144 }
2145
2146 /*
2147 * We're not actually writing here, but doing three things:
2148 *
2149 * 1. Identify the chunk the buffer belongs to.
2150 * 2. If the chunk is full or the buffer doesn't belong to the current
2151 * chunk, then start a new chunk and flush() the old chunk.
2152 * 3. To keep the hardware busy, we also group chunks into batches
2153 * and only require that a batch gets acknowledged in the completion
2154 * qeueue instead of each individual chunk.
2155 */
2156 static int qemu_rdma_write(QEMUFile *f, RDMAContext *rdma,
2157 uint64_t block_offset, uint64_t offset,
2158 uint64_t len)
2159 {
2160 uint64_t current_addr = block_offset + offset;
2161 uint64_t index = rdma->current_index;
2162 uint64_t chunk = rdma->current_chunk;
2163 int ret;
2164
2165 /* If we cannot merge it, we flush the current buffer first. */
2166 if (!qemu_rdma_buffer_mergable(rdma, current_addr, len)) {
2167 ret = qemu_rdma_write_flush(f, rdma);
2168 if (ret) {
2169 return ret;
2170 }
2171 rdma->current_length = 0;
2172 rdma->current_addr = current_addr;
2173
2174 ret = qemu_rdma_search_ram_block(rdma, block_offset,
2175 offset, len, &index, &chunk);
2176 if (ret) {
2177 fprintf(stderr, "ram block search failed\n");
2178 return ret;
2179 }
2180 rdma->current_index = index;
2181 rdma->current_chunk = chunk;
2182 }
2183
2184 /* merge it */
2185 rdma->current_length += len;
2186
2187 /* flush it if buffer is too large */
2188 if (rdma->current_length >= RDMA_MERGE_MAX) {
2189 return qemu_rdma_write_flush(f, rdma);
2190 }
2191
2192 return 0;
2193 }
2194
2195 static void qemu_rdma_cleanup(RDMAContext *rdma)
2196 {
2197 struct rdma_cm_event *cm_event;
2198 int ret, idx;
2199
2200 if (rdma->cm_id && rdma->connected) {
2201 if (rdma->error_state) {
2202 RDMAControlHeader head = { .len = 0,
2203 .type = RDMA_CONTROL_ERROR,
2204 .repeat = 1,
2205 };
2206 fprintf(stderr, "Early error. Sending error.\n");
2207 qemu_rdma_post_send_control(rdma, NULL, &head);
2208 }
2209
2210 ret = rdma_disconnect(rdma->cm_id);
2211 if (!ret) {
2212 DDPRINTF("waiting for disconnect\n");
2213 ret = rdma_get_cm_event(rdma->channel, &cm_event);
2214 if (!ret) {
2215 rdma_ack_cm_event(cm_event);
2216 }
2217 }
2218 DDPRINTF("Disconnected.\n");
2219 rdma->connected = false;
2220 }
2221
2222 g_free(rdma->block);
2223 rdma->block = NULL;
2224
2225 for (idx = 0; idx < RDMA_WRID_MAX; idx++) {
2226 if (rdma->wr_data[idx].control_mr) {
2227 rdma->total_registrations--;
2228 ibv_dereg_mr(rdma->wr_data[idx].control_mr);
2229 }
2230 rdma->wr_data[idx].control_mr = NULL;
2231 }
2232
2233 if (rdma->local_ram_blocks.block) {
2234 while (rdma->local_ram_blocks.nb_blocks) {
2235 __qemu_rdma_delete_block(rdma,
2236 rdma->local_ram_blocks.block->offset);
2237 }
2238 }
2239
2240 if (rdma->qp) {
2241 rdma_destroy_qp(rdma->cm_id);
2242 rdma->qp = NULL;
2243 }
2244 if (rdma->cq) {
2245 ibv_destroy_cq(rdma->cq);
2246 rdma->cq = NULL;
2247 }
2248 if (rdma->comp_channel) {
2249 ibv_destroy_comp_channel(rdma->comp_channel);
2250 rdma->comp_channel = NULL;
2251 }
2252 if (rdma->pd) {
2253 ibv_dealloc_pd(rdma->pd);
2254 rdma->pd = NULL;
2255 }
2256 if (rdma->listen_id) {
2257 rdma_destroy_id(rdma->listen_id);
2258 rdma->listen_id = NULL;
2259 }
2260 if (rdma->cm_id) {
2261 rdma_destroy_id(rdma->cm_id);
2262 rdma->cm_id = NULL;
2263 }
2264 if (rdma->channel) {
2265 rdma_destroy_event_channel(rdma->channel);
2266 rdma->channel = NULL;
2267 }
2268 g_free(rdma->host);
2269 rdma->host = NULL;
2270 }
2271
2272
2273 static int qemu_rdma_source_init(RDMAContext *rdma, Error **errp, bool pin_all)
2274 {
2275 int ret, idx;
2276 Error *local_err = NULL, **temp = &local_err;
2277
2278 /*
2279 * Will be validated against destination's actual capabilities
2280 * after the connect() completes.
2281 */
2282 rdma->pin_all = pin_all;
2283
2284 ret = qemu_rdma_resolve_host(rdma, temp);
2285 if (ret) {
2286 goto err_rdma_source_init;
2287 }
2288
2289 ret = qemu_rdma_alloc_pd_cq(rdma);
2290 if (ret) {
2291 ERROR(temp, "rdma migration: error allocating pd and cq! Your mlock()"
2292 " limits may be too low. Please check $ ulimit -a # and "
2293 "search for 'ulimit -l' in the output");
2294 goto err_rdma_source_init;
2295 }
2296
2297 ret = qemu_rdma_alloc_qp(rdma);
2298 if (ret) {
2299 ERROR(temp, "rdma migration: error allocating qp!");
2300 goto err_rdma_source_init;
2301 }
2302
2303 ret = qemu_rdma_init_ram_blocks(rdma);
2304 if (ret) {
2305 ERROR(temp, "rdma migration: error initializing ram blocks!");
2306 goto err_rdma_source_init;
2307 }
2308
2309 for (idx = 0; idx < RDMA_WRID_MAX; idx++) {
2310 ret = qemu_rdma_reg_control(rdma, idx);
2311 if (ret) {
2312 ERROR(temp, "rdma migration: error registering %d control!",
2313 idx);
2314 goto err_rdma_source_init;
2315 }
2316 }
2317
2318 return 0;
2319
2320 err_rdma_source_init:
2321 error_propagate(errp, local_err);
2322 qemu_rdma_cleanup(rdma);
2323 return -1;
2324 }
2325
2326 static int qemu_rdma_connect(RDMAContext *rdma, Error **errp)
2327 {
2328 RDMACapabilities cap = {
2329 .version = RDMA_CONTROL_VERSION_CURRENT,
2330 .flags = 0,
2331 };
2332 struct rdma_conn_param conn_param = { .initiator_depth = 2,
2333 .retry_count = 5,
2334 .private_data = &cap,
2335 .private_data_len = sizeof(cap),
2336 };
2337 struct rdma_cm_event *cm_event;
2338 int ret;
2339
2340 /*
2341 * Only negotiate the capability with destination if the user
2342 * on the source first requested the capability.
2343 */
2344 if (rdma->pin_all) {
2345 DPRINTF("Server pin-all memory requested.\n");
2346 cap.flags |= RDMA_CAPABILITY_PIN_ALL;
2347 }
2348
2349 caps_to_network(&cap);
2350
2351 ret = rdma_connect(rdma->cm_id, &conn_param);
2352 if (ret) {
2353 perror("rdma_connect");
2354 ERROR(errp, "connecting to destination!");
2355 rdma_destroy_id(rdma->cm_id);
2356 rdma->cm_id = NULL;
2357 goto err_rdma_source_connect;
2358 }
2359
2360 ret = rdma_get_cm_event(rdma->channel, &cm_event);
2361 if (ret) {
2362 perror("rdma_get_cm_event after rdma_connect");
2363 ERROR(errp, "connecting to destination!");
2364 rdma_ack_cm_event(cm_event);
2365 rdma_destroy_id(rdma->cm_id);
2366 rdma->cm_id = NULL;
2367 goto err_rdma_source_connect;
2368 }
2369
2370 if (cm_event->event != RDMA_CM_EVENT_ESTABLISHED) {
2371 perror("rdma_get_cm_event != EVENT_ESTABLISHED after rdma_connect");
2372 ERROR(errp, "connecting to destination!");
2373 rdma_ack_cm_event(cm_event);
2374 rdma_destroy_id(rdma->cm_id);
2375 rdma->cm_id = NULL;
2376 goto err_rdma_source_connect;
2377 }
2378 rdma->connected = true;
2379
2380 memcpy(&cap, cm_event->param.conn.private_data, sizeof(cap));
2381 network_to_caps(&cap);
2382
2383 /*
2384 * Verify that the *requested* capabilities are supported by the destination
2385 * and disable them otherwise.
2386 */
2387 if (rdma->pin_all && !(cap.flags & RDMA_CAPABILITY_PIN_ALL)) {
2388 ERROR(errp, "Server cannot support pinning all memory. "
2389 "Will register memory dynamically.");
2390 rdma->pin_all = false;
2391 }
2392
2393 DPRINTF("Pin all memory: %s\n", rdma->pin_all ? "enabled" : "disabled");
2394
2395 rdma_ack_cm_event(cm_event);
2396
2397 ret = qemu_rdma_post_recv_control(rdma, RDMA_WRID_READY);
2398 if (ret) {
2399 ERROR(errp, "posting second control recv!");
2400 goto err_rdma_source_connect;
2401 }
2402
2403 rdma->control_ready_expected = 1;
2404 rdma->nb_sent = 0;
2405 return 0;
2406
2407 err_rdma_source_connect:
2408 qemu_rdma_cleanup(rdma);
2409 return -1;
2410 }
2411
2412 static int qemu_rdma_dest_init(RDMAContext *rdma, Error **errp)
2413 {
2414 int ret = -EINVAL, idx;
2415 struct rdma_cm_id *listen_id;
2416 char ip[40] = "unknown";
2417 struct rdma_addrinfo *res;
2418 char port_str[16];
2419
2420 for (idx = 0; idx < RDMA_WRID_MAX; idx++) {
2421 rdma->wr_data[idx].control_len = 0;
2422 rdma->wr_data[idx].control_curr = NULL;
2423 }
2424
2425 if (rdma->host == NULL) {
2426 ERROR(errp, "RDMA host is not set!");
2427 rdma->error_state = -EINVAL;
2428 return -1;
2429 }
2430 /* create CM channel */
2431 rdma->channel = rdma_create_event_channel();
2432 if (!rdma->channel) {
2433 ERROR(errp, "could not create rdma event channel");
2434 rdma->error_state = -EINVAL;
2435 return -1;
2436 }
2437
2438 /* create CM id */
2439 ret = rdma_create_id(rdma->channel, &listen_id, NULL, RDMA_PS_TCP);
2440 if (ret) {
2441 ERROR(errp, "could not create cm_id!");
2442 goto err_dest_init_create_listen_id;
2443 }
2444
2445 snprintf(port_str, 16, "%d", rdma->port);
2446 port_str[15] = '\0';
2447
2448 if (rdma->host && strcmp("", rdma->host)) {
2449 struct rdma_addrinfo *e;
2450
2451 ret = rdma_getaddrinfo(rdma->host, port_str, NULL, &res);
2452 if (ret < 0) {
2453 ERROR(errp, "could not rdma_getaddrinfo address %s", rdma->host);
2454 goto err_dest_init_bind_addr;
2455 }
2456
2457 for (e = res; e != NULL; e = e->ai_next) {
2458 inet_ntop(e->ai_family,
2459 &((struct sockaddr_in *) e->ai_dst_addr)->sin_addr, ip, sizeof ip);
2460 DPRINTF("Trying %s => %s\n", rdma->host, ip);
2461 ret = rdma_bind_addr(listen_id, e->ai_dst_addr);
2462 if (!ret) {
2463 if (e->ai_family == AF_INET6) {
2464 ret = qemu_rdma_broken_ipv6_kernel(errp, listen_id->verbs);
2465 if (ret) {
2466 continue;
2467 }
2468 }
2469
2470 goto listen;
2471 }
2472 }
2473
2474 ERROR(errp, "Error: could not rdma_bind_addr!");
2475 goto err_dest_init_bind_addr;
2476 } else {
2477 ERROR(errp, "migration host and port not specified!");
2478 ret = -EINVAL;
2479 goto err_dest_init_bind_addr;
2480 }
2481 listen:
2482
2483 rdma->listen_id = listen_id;
2484 qemu_rdma_dump_gid("dest_init", listen_id);
2485 return 0;
2486
2487 err_dest_init_bind_addr:
2488 rdma_destroy_id(listen_id);
2489 err_dest_init_create_listen_id:
2490 rdma_destroy_event_channel(rdma->channel);
2491 rdma->channel = NULL;
2492 rdma->error_state = ret;
2493 return ret;
2494
2495 }
2496
2497 static void *qemu_rdma_data_init(const char *host_port, Error **errp)
2498 {
2499 RDMAContext *rdma = NULL;
2500 InetSocketAddress *addr;
2501
2502 if (host_port) {
2503 rdma = g_malloc0(sizeof(RDMAContext));
2504 memset(rdma, 0, sizeof(RDMAContext));
2505 rdma->current_index = -1;
2506 rdma->current_chunk = -1;
2507
2508 addr = inet_parse(host_port, NULL);
2509 if (addr != NULL) {
2510 rdma->port = atoi(addr->port);
2511 rdma->host = g_strdup(addr->host);
2512 } else {
2513 ERROR(errp, "bad RDMA migration address '%s'", host_port);
2514 g_free(rdma);
2515 return NULL;
2516 }
2517 }
2518
2519 return rdma;
2520 }
2521
2522 /*
2523 * QEMUFile interface to the control channel.
2524 * SEND messages for control only.
2525 * pc.ram is handled with regular RDMA messages.
2526 */
2527 static int qemu_rdma_put_buffer(void *opaque, const uint8_t *buf,
2528 int64_t pos, int size)
2529 {
2530 QEMUFileRDMA *r = opaque;
2531 QEMUFile *f = r->file;
2532 RDMAContext *rdma = r->rdma;
2533 size_t remaining = size;
2534 uint8_t * data = (void *) buf;
2535 int ret;
2536
2537 CHECK_ERROR_STATE();
2538
2539 /*
2540 * Push out any writes that
2541 * we're queued up for pc.ram.
2542 */
2543 ret = qemu_rdma_write_flush(f, rdma);
2544 if (ret < 0) {
2545 rdma->error_state = ret;
2546 return ret;
2547 }
2548
2549 while (remaining) {
2550 RDMAControlHeader head;
2551
2552 r->len = MIN(remaining, RDMA_SEND_INCREMENT);
2553 remaining -= r->len;
2554
2555 head.len = r->len;
2556 head.type = RDMA_CONTROL_QEMU_FILE;
2557
2558 ret = qemu_rdma_exchange_send(rdma, &head, data, NULL, NULL, NULL);
2559
2560 if (ret < 0) {
2561 rdma->error_state = ret;
2562 return ret;
2563 }
2564
2565 data += r->len;
2566 }
2567
2568 return size;
2569 }
2570
2571 static size_t qemu_rdma_fill(RDMAContext *rdma, uint8_t *buf,
2572 int size, int idx)
2573 {
2574 size_t len = 0;
2575
2576 if (rdma->wr_data[idx].control_len) {
2577 DDDPRINTF("RDMA %" PRId64 " of %d bytes already in buffer\n",
2578 rdma->wr_data[idx].control_len, size);
2579
2580 len = MIN(size, rdma->wr_data[idx].control_len);
2581 memcpy(buf, rdma->wr_data[idx].control_curr, len);
2582 rdma->wr_data[idx].control_curr += len;
2583 rdma->wr_data[idx].control_len -= len;
2584 }
2585
2586 return len;
2587 }
2588
2589 /*
2590 * QEMUFile interface to the control channel.
2591 * RDMA links don't use bytestreams, so we have to
2592 * return bytes to QEMUFile opportunistically.
2593 */
2594 static int qemu_rdma_get_buffer(void *opaque, uint8_t *buf,
2595 int64_t pos, int size)
2596 {
2597 QEMUFileRDMA *r = opaque;
2598 RDMAContext *rdma = r->rdma;
2599 RDMAControlHeader head;
2600 int ret = 0;
2601
2602 CHECK_ERROR_STATE();
2603
2604 /*
2605 * First, we hold on to the last SEND message we
2606 * were given and dish out the bytes until we run
2607 * out of bytes.
2608 */
2609 r->len = qemu_rdma_fill(r->rdma, buf, size, 0);
2610 if (r->len) {
2611 return r->len;
2612 }
2613
2614 /*
2615 * Once we run out, we block and wait for another
2616 * SEND message to arrive.
2617 */
2618 ret = qemu_rdma_exchange_recv(rdma, &head, RDMA_CONTROL_QEMU_FILE);
2619
2620 if (ret < 0) {
2621 rdma->error_state = ret;
2622 return ret;
2623 }
2624
2625 /*
2626 * SEND was received with new bytes, now try again.
2627 */
2628 return qemu_rdma_fill(r->rdma, buf, size, 0);
2629 }
2630
2631 /*
2632 * Block until all the outstanding chunks have been delivered by the hardware.
2633 */
2634 static int qemu_rdma_drain_cq(QEMUFile *f, RDMAContext *rdma)
2635 {
2636 int ret;
2637
2638 if (qemu_rdma_write_flush(f, rdma) < 0) {
2639 return -EIO;
2640 }
2641
2642 while (rdma->nb_sent) {
2643 ret = qemu_rdma_block_for_wrid(rdma, RDMA_WRID_RDMA_WRITE, NULL);
2644 if (ret < 0) {
2645 fprintf(stderr, "rdma migration: complete polling error!\n");
2646 return -EIO;
2647 }
2648 }
2649
2650 qemu_rdma_unregister_waiting(rdma);
2651
2652 return 0;
2653 }
2654
2655 static int qemu_rdma_close(void *opaque)
2656 {
2657 DPRINTF("Shutting down connection.\n");
2658 QEMUFileRDMA *r = opaque;
2659 if (r->rdma) {
2660 qemu_rdma_cleanup(r->rdma);
2661 g_free(r->rdma);
2662 }
2663 g_free(r);
2664 return 0;
2665 }
2666
2667 /*
2668 * Parameters:
2669 * @offset == 0 :
2670 * This means that 'block_offset' is a full virtual address that does not
2671 * belong to a RAMBlock of the virtual machine and instead
2672 * represents a private malloc'd memory area that the caller wishes to
2673 * transfer.
2674 *
2675 * @offset != 0 :
2676 * Offset is an offset to be added to block_offset and used
2677 * to also lookup the corresponding RAMBlock.
2678 *
2679 * @size > 0 :
2680 * Initiate an transfer this size.
2681 *
2682 * @size == 0 :
2683 * A 'hint' or 'advice' that means that we wish to speculatively
2684 * and asynchronously unregister this memory. In this case, there is no
2685 * guarantee that the unregister will actually happen, for example,
2686 * if the memory is being actively transmitted. Additionally, the memory
2687 * may be re-registered at any future time if a write within the same
2688 * chunk was requested again, even if you attempted to unregister it
2689 * here.
2690 *
2691 * @size < 0 : TODO, not yet supported
2692 * Unregister the memory NOW. This means that the caller does not
2693 * expect there to be any future RDMA transfers and we just want to clean
2694 * things up. This is used in case the upper layer owns the memory and
2695 * cannot wait for qemu_fclose() to occur.
2696 *
2697 * @bytes_sent : User-specificed pointer to indicate how many bytes were
2698 * sent. Usually, this will not be more than a few bytes of
2699 * the protocol because most transfers are sent asynchronously.
2700 */
2701 static size_t qemu_rdma_save_page(QEMUFile *f, void *opaque,
2702 ram_addr_t block_offset, ram_addr_t offset,
2703 size_t size, int *bytes_sent)
2704 {
2705 QEMUFileRDMA *rfile = opaque;
2706 RDMAContext *rdma = rfile->rdma;
2707 int ret;
2708
2709 CHECK_ERROR_STATE();
2710
2711 qemu_fflush(f);
2712
2713 if (size > 0) {
2714 /*
2715 * Add this page to the current 'chunk'. If the chunk
2716 * is full, or the page doen't belong to the current chunk,
2717 * an actual RDMA write will occur and a new chunk will be formed.
2718 */
2719 ret = qemu_rdma_write(f, rdma, block_offset, offset, size);
2720 if (ret < 0) {
2721 fprintf(stderr, "rdma migration: write error! %d\n", ret);
2722 goto err;
2723 }
2724
2725 /*
2726 * We always return 1 bytes because the RDMA
2727 * protocol is completely asynchronous. We do not yet know
2728 * whether an identified chunk is zero or not because we're
2729 * waiting for other pages to potentially be merged with
2730 * the current chunk. So, we have to call qemu_update_position()
2731 * later on when the actual write occurs.
2732 */
2733 if (bytes_sent) {
2734 *bytes_sent = 1;
2735 }
2736 } else {
2737 uint64_t index, chunk;
2738
2739 /* TODO: Change QEMUFileOps prototype to be signed: size_t => long
2740 if (size < 0) {
2741 ret = qemu_rdma_drain_cq(f, rdma);
2742 if (ret < 0) {
2743 fprintf(stderr, "rdma: failed to synchronously drain"
2744 " completion queue before unregistration.\n");
2745 goto err;
2746 }
2747 }
2748 */
2749
2750 ret = qemu_rdma_search_ram_block(rdma, block_offset,
2751 offset, size, &index, &chunk);
2752
2753 if (ret) {
2754 fprintf(stderr, "ram block search failed\n");
2755 goto err;
2756 }
2757
2758 qemu_rdma_signal_unregister(rdma, index, chunk, 0);
2759
2760 /*
2761 * TODO: Synchronous, guaranteed unregistration (should not occur during
2762 * fast-path). Otherwise, unregisters will process on the next call to
2763 * qemu_rdma_drain_cq()
2764 if (size < 0) {
2765 qemu_rdma_unregister_waiting(rdma);
2766 }
2767 */
2768 }
2769
2770 /*
2771 * Drain the Completion Queue if possible, but do not block,
2772 * just poll.
2773 *
2774 * If nothing to poll, the end of the iteration will do this
2775 * again to make sure we don't overflow the request queue.
2776 */
2777 while (1) {
2778 uint64_t wr_id, wr_id_in;
2779 int ret = qemu_rdma_poll(rdma, &wr_id_in, NULL);
2780 if (ret < 0) {
2781 fprintf(stderr, "rdma migration: polling error! %d\n", ret);
2782 goto err;
2783 }
2784
2785 wr_id = wr_id_in & RDMA_WRID_TYPE_MASK;
2786
2787 if (wr_id == RDMA_WRID_NONE) {
2788 break;
2789 }
2790 }
2791
2792 return RAM_SAVE_CONTROL_DELAYED;
2793 err:
2794 rdma->error_state = ret;
2795 return ret;
2796 }
2797
2798 static int qemu_rdma_accept(RDMAContext *rdma)
2799 {
2800 RDMACapabilities cap;
2801 struct rdma_conn_param conn_param = {
2802 .responder_resources = 2,
2803 .private_data = &cap,
2804 .private_data_len = sizeof(cap),
2805 };
2806 struct rdma_cm_event *cm_event;
2807 struct ibv_context *verbs;
2808 int ret = -EINVAL;
2809 int idx;
2810
2811 ret = rdma_get_cm_event(rdma->channel, &cm_event);
2812 if (ret) {
2813 goto err_rdma_dest_wait;
2814 }
2815
2816 if (cm_event->event != RDMA_CM_EVENT_CONNECT_REQUEST) {
2817 rdma_ack_cm_event(cm_event);
2818 goto err_rdma_dest_wait;
2819 }
2820
2821 memcpy(&cap, cm_event->param.conn.private_data, sizeof(cap));
2822
2823 network_to_caps(&cap);
2824
2825 if (cap.version < 1 || cap.version > RDMA_CONTROL_VERSION_CURRENT) {
2826 fprintf(stderr, "Unknown source RDMA version: %d, bailing...\n",
2827 cap.version);
2828 rdma_ack_cm_event(cm_event);
2829 goto err_rdma_dest_wait;
2830 }
2831
2832 /*
2833 * Respond with only the capabilities this version of QEMU knows about.
2834 */
2835 cap.flags &= known_capabilities;
2836
2837 /*
2838 * Enable the ones that we do know about.
2839 * Add other checks here as new ones are introduced.
2840 */
2841 if (cap.flags & RDMA_CAPABILITY_PIN_ALL) {
2842 rdma->pin_all = true;
2843 }
2844
2845 rdma->cm_id = cm_event->id;
2846 verbs = cm_event->id->verbs;
2847
2848 rdma_ack_cm_event(cm_event);
2849
2850 DPRINTF("Memory pin all: %s\n", rdma->pin_all ? "enabled" : "disabled");
2851
2852 caps_to_network(&cap);
2853
2854 DPRINTF("verbs context after listen: %p\n", verbs);
2855
2856 if (!rdma->verbs) {
2857 rdma->verbs = verbs;
2858 } else if (rdma->verbs != verbs) {
2859 fprintf(stderr, "ibv context not matching %p, %p!\n",
2860 rdma->verbs, verbs);
2861 goto err_rdma_dest_wait;
2862 }
2863
2864 qemu_rdma_dump_id("dest_init", verbs);
2865
2866 ret = qemu_rdma_alloc_pd_cq(rdma);
2867 if (ret) {
2868 fprintf(stderr, "rdma migration: error allocating pd and cq!\n");
2869 goto err_rdma_dest_wait;
2870 }
2871
2872 ret = qemu_rdma_alloc_qp(rdma);
2873 if (ret) {
2874 fprintf(stderr, "rdma migration: error allocating qp!\n");
2875 goto err_rdma_dest_wait;
2876 }
2877
2878 ret = qemu_rdma_init_ram_blocks(rdma);
2879 if (ret) {
2880 fprintf(stderr, "rdma migration: error initializing ram blocks!\n");
2881 goto err_rdma_dest_wait;
2882 }
2883
2884 for (idx = 0; idx < RDMA_WRID_MAX; idx++) {
2885 ret = qemu_rdma_reg_control(rdma, idx);
2886 if (ret) {
2887 fprintf(stderr, "rdma: error registering %d control!\n", idx);
2888 goto err_rdma_dest_wait;
2889 }
2890 }
2891
2892 qemu_set_fd_handler2(rdma->channel->fd, NULL, NULL, NULL, NULL);
2893
2894 ret = rdma_accept(rdma->cm_id, &conn_param);
2895 if (ret) {
2896 fprintf(stderr, "rdma_accept returns %d!\n", ret);
2897 goto err_rdma_dest_wait;
2898 }
2899
2900 ret = rdma_get_cm_event(rdma->channel, &cm_event);
2901 if (ret) {
2902 fprintf(stderr, "rdma_accept get_cm_event failed %d!\n", ret);
2903 goto err_rdma_dest_wait;
2904 }
2905
2906 if (cm_event->event != RDMA_CM_EVENT_ESTABLISHED) {
2907 fprintf(stderr, "rdma_accept not event established!\n");
2908 rdma_ack_cm_event(cm_event);
2909 goto err_rdma_dest_wait;
2910 }
2911
2912 rdma_ack_cm_event(cm_event);
2913 rdma->connected = true;
2914
2915 ret = qemu_rdma_post_recv_control(rdma, RDMA_WRID_READY);
2916 if (ret) {
2917 fprintf(stderr, "rdma migration: error posting second control recv!\n");
2918 goto err_rdma_dest_wait;
2919 }
2920
2921 qemu_rdma_dump_gid("dest_connect", rdma->cm_id);
2922
2923 return 0;
2924
2925 err_rdma_dest_wait:
2926 rdma->error_state = ret;
2927 qemu_rdma_cleanup(rdma);
2928 return ret;
2929 }
2930
2931 /*
2932 * During each iteration of the migration, we listen for instructions
2933 * by the source VM to perform dynamic page registrations before they
2934 * can perform RDMA operations.
2935 *
2936 * We respond with the 'rkey'.
2937 *
2938 * Keep doing this until the source tells us to stop.
2939 */
2940 static int qemu_rdma_registration_handle(QEMUFile *f, void *opaque,
2941 uint64_t flags)
2942 {
2943 RDMAControlHeader reg_resp = { .len = sizeof(RDMARegisterResult),
2944 .type = RDMA_CONTROL_REGISTER_RESULT,
2945 .repeat = 0,
2946 };
2947 RDMAControlHeader unreg_resp = { .len = 0,
2948 .type = RDMA_CONTROL_UNREGISTER_FINISHED,
2949 .repeat = 0,
2950 };
2951 RDMAControlHeader blocks = { .type = RDMA_CONTROL_RAM_BLOCKS_RESULT,
2952 .repeat = 1 };
2953 QEMUFileRDMA *rfile = opaque;
2954 RDMAContext *rdma = rfile->rdma;
2955 RDMALocalBlocks *local = &rdma->local_ram_blocks;
2956 RDMAControlHeader head;
2957 RDMARegister *reg, *registers;
2958 RDMACompress *comp;
2959 RDMARegisterResult *reg_result;
2960 static RDMARegisterResult results[RDMA_CONTROL_MAX_COMMANDS_PER_MESSAGE];
2961 RDMALocalBlock *block;
2962 void *host_addr;
2963 int ret = 0;
2964 int idx = 0;
2965 int count = 0;
2966 int i = 0;
2967
2968 CHECK_ERROR_STATE();
2969
2970 do {
2971 DDDPRINTF("Waiting for next request %" PRIu64 "...\n", flags);
2972
2973 ret = qemu_rdma_exchange_recv(rdma, &head, RDMA_CONTROL_NONE);
2974
2975 if (ret < 0) {
2976 break;
2977 }
2978
2979 if (head.repeat > RDMA_CONTROL_MAX_COMMANDS_PER_MESSAGE) {
2980 fprintf(stderr, "rdma: Too many requests in this message (%d)."
2981 "Bailing.\n", head.repeat);
2982 ret = -EIO;
2983 break;
2984 }
2985
2986 switch (head.type) {
2987 case RDMA_CONTROL_COMPRESS:
2988 comp = (RDMACompress *) rdma->wr_data[idx].control_curr;
2989 network_to_compress(comp);
2990
2991 DDPRINTF("Zapping zero chunk: %" PRId64
2992 " bytes, index %d, offset %" PRId64 "\n",
2993 comp->length, comp->block_idx, comp->offset);
2994 block = &(rdma->local_ram_blocks.block[comp->block_idx]);
2995
2996 host_addr = block->local_host_addr +
2997 (comp->offset - block->offset);
2998
2999 ram_handle_compressed(host_addr, comp->value, comp->length);
3000 break;
3001
3002 case RDMA_CONTROL_REGISTER_FINISHED:
3003 DDDPRINTF("Current registrations complete.\n");
3004 goto out;
3005
3006 case RDMA_CONTROL_RAM_BLOCKS_REQUEST:
3007 DPRINTF("Initial setup info requested.\n");
3008
3009 if (rdma->pin_all) {
3010 ret = qemu_rdma_reg_whole_ram_blocks(rdma);
3011 if (ret) {
3012 fprintf(stderr, "rdma migration: error dest "
3013 "registering ram blocks!\n");
3014 goto out;
3015 }
3016 }
3017
3018 /*
3019 * Dest uses this to prepare to transmit the RAMBlock descriptions
3020 * to the source VM after connection setup.
3021 * Both sides use the "remote" structure to communicate and update
3022 * their "local" descriptions with what was sent.
3023 */
3024 for (i = 0; i < local->nb_blocks; i++) {
3025 rdma->block[i].remote_host_addr =
3026 (uint64_t)(local->block[i].local_host_addr);
3027
3028 if (rdma->pin_all) {
3029 rdma->block[i].remote_rkey = local->block[i].mr->rkey;
3030 }
3031
3032 rdma->block[i].offset = local->block[i].offset;
3033 rdma->block[i].length = local->block[i].length;
3034
3035 remote_block_to_network(&rdma->block[i]);
3036 }
3037
3038 blocks.len = rdma->local_ram_blocks.nb_blocks
3039 * sizeof(RDMARemoteBlock);
3040
3041
3042 ret = qemu_rdma_post_send_control(rdma,
3043 (uint8_t *) rdma->block, &blocks);
3044
3045 if (ret < 0) {
3046 fprintf(stderr, "rdma migration: error sending remote info!\n");
3047 goto out;
3048 }
3049
3050 break;
3051 case RDMA_CONTROL_REGISTER_REQUEST:
3052 DDPRINTF("There are %d registration requests\n", head.repeat);
3053
3054 reg_resp.repeat = head.repeat;
3055 registers = (RDMARegister *) rdma->wr_data[idx].control_curr;
3056
3057 for (count = 0; count < head.repeat; count++) {
3058 uint64_t chunk;
3059 uint8_t *chunk_start, *chunk_end;
3060
3061 reg = &registers[count];
3062 network_to_register(reg);
3063
3064 reg_result = &results[count];
3065
3066 DDPRINTF("Registration request (%d): index %d, current_addr %"
3067 PRIu64 " chunks: %" PRIu64 "\n", count,
3068 reg->current_index, reg->key.current_addr, reg->chunks);
3069
3070 block = &(rdma->local_ram_blocks.block[reg->current_index]);
3071 if (block->is_ram_block) {
3072 host_addr = (block->local_host_addr +
3073 (reg->key.current_addr - block->offset));
3074 chunk = ram_chunk_index(block->local_host_addr,
3075 (uint8_t *) host_addr);
3076 } else {
3077 chunk = reg->key.chunk;
3078 host_addr = block->local_host_addr +
3079 (reg->key.chunk * (1UL << RDMA_REG_CHUNK_SHIFT));
3080 }
3081 chunk_start = ram_chunk_start(block, chunk);
3082 chunk_end = ram_chunk_end(block, chunk + reg->chunks);
3083 if (qemu_rdma_register_and_get_keys(rdma, block,
3084 (uint8_t *)host_addr, NULL, &reg_result->rkey,
3085 chunk, chunk_start, chunk_end)) {
3086 fprintf(stderr, "cannot get rkey!\n");
3087 ret = -EINVAL;
3088 goto out;
3089 }
3090
3091 reg_result->host_addr = (uint64_t) block->local_host_addr;
3092
3093 DDPRINTF("Registered rkey for this request: %x\n",
3094 reg_result->rkey);
3095
3096 result_to_network(reg_result);
3097 }
3098
3099 ret = qemu_rdma_post_send_control(rdma,
3100 (uint8_t *) results, &reg_resp);
3101
3102 if (ret < 0) {
3103 fprintf(stderr, "Failed to send control buffer!\n");
3104 goto out;
3105 }
3106 break;
3107 case RDMA_CONTROL_UNREGISTER_REQUEST:
3108 DDPRINTF("There are %d unregistration requests\n", head.repeat);
3109 unreg_resp.repeat = head.repeat;
3110 registers = (RDMARegister *) rdma->wr_data[idx].control_curr;
3111
3112 for (count = 0; count < head.repeat; count++) {
3113 reg = &registers[count];
3114 network_to_register(reg);
3115
3116 DDPRINTF("Unregistration request (%d): "
3117 " index %d, chunk %" PRIu64 "\n",
3118 count, reg->current_index, reg->key.chunk);
3119
3120 block = &(rdma->local_ram_blocks.block[reg->current_index]);
3121
3122 ret = ibv_dereg_mr(block->pmr[reg->key.chunk]);
3123 block->pmr[reg->key.chunk] = NULL;
3124
3125 if (ret != 0) {
3126 perror("rdma unregistration chunk failed");
3127 ret = -ret;
3128 goto out;
3129 }
3130
3131 rdma->total_registrations--;
3132
3133 DDPRINTF("Unregistered chunk %" PRIu64 " successfully.\n",
3134 reg->key.chunk);
3135 }
3136
3137 ret = qemu_rdma_post_send_control(rdma, NULL, &unreg_resp);
3138
3139 if (ret < 0) {
3140 fprintf(stderr, "Failed to send control buffer!\n");
3141 goto out;
3142 }
3143 break;
3144 case RDMA_CONTROL_REGISTER_RESULT:
3145 fprintf(stderr, "Invalid RESULT message at dest.\n");
3146 ret = -EIO;
3147 goto out;
3148 default:
3149 fprintf(stderr, "Unknown control message %s\n",
3150 control_desc[head.type]);
3151 ret = -EIO;
3152 goto out;
3153 }
3154 } while (1);
3155 out:
3156 if (ret < 0) {
3157 rdma->error_state = ret;
3158 }
3159 return ret;
3160 }
3161
3162 static int qemu_rdma_registration_start(QEMUFile *f, void *opaque,
3163 uint64_t flags)
3164 {
3165 QEMUFileRDMA *rfile = opaque;
3166 RDMAContext *rdma = rfile->rdma;
3167
3168 CHECK_ERROR_STATE();
3169
3170 DDDPRINTF("start section: %" PRIu64 "\n", flags);
3171 qemu_put_be64(f, RAM_SAVE_FLAG_HOOK);
3172 qemu_fflush(f);
3173
3174 return 0;
3175 }
3176
3177 /*
3178 * Inform dest that dynamic registrations are done for now.
3179 * First, flush writes, if any.
3180 */
3181 static int qemu_rdma_registration_stop(QEMUFile *f, void *opaque,
3182 uint64_t flags)
3183 {
3184 Error *local_err = NULL, **errp = &local_err;
3185 QEMUFileRDMA *rfile = opaque;
3186 RDMAContext *rdma = rfile->rdma;
3187 RDMAControlHeader head = { .len = 0, .repeat = 1 };
3188 int ret = 0;
3189
3190 CHECK_ERROR_STATE();
3191
3192 qemu_fflush(f);
3193 ret = qemu_rdma_drain_cq(f, rdma);
3194
3195 if (ret < 0) {
3196 goto err;
3197 }
3198
3199 if (flags == RAM_CONTROL_SETUP) {
3200 RDMAControlHeader resp = {.type = RDMA_CONTROL_RAM_BLOCKS_RESULT };
3201 RDMALocalBlocks *local = &rdma->local_ram_blocks;
3202 int reg_result_idx, i, j, nb_remote_blocks;
3203
3204 head.type = RDMA_CONTROL_RAM_BLOCKS_REQUEST;
3205 DPRINTF("Sending registration setup for ram blocks...\n");
3206
3207 /*
3208 * Make sure that we parallelize the pinning on both sides.
3209 * For very large guests, doing this serially takes a really
3210 * long time, so we have to 'interleave' the pinning locally
3211 * with the control messages by performing the pinning on this
3212 * side before we receive the control response from the other
3213 * side that the pinning has completed.
3214 */
3215 ret = qemu_rdma_exchange_send(rdma, &head, NULL, &resp,
3216 &reg_result_idx, rdma->pin_all ?
3217 qemu_rdma_reg_whole_ram_blocks : NULL);
3218 if (ret < 0) {
3219 ERROR(errp, "receiving remote info!");
3220 return ret;
3221 }
3222
3223 nb_remote_blocks = resp.len / sizeof(RDMARemoteBlock);
3224
3225 /*
3226 * The protocol uses two different sets of rkeys (mutually exclusive):
3227 * 1. One key to represent the virtual address of the entire ram block.
3228 * (dynamic chunk registration disabled - pin everything with one rkey.)
3229 * 2. One to represent individual chunks within a ram block.
3230 * (dynamic chunk registration enabled - pin individual chunks.)
3231 *
3232 * Once the capability is successfully negotiated, the destination transmits
3233 * the keys to use (or sends them later) including the virtual addresses
3234 * and then propagates the remote ram block descriptions to his local copy.
3235 */
3236
3237 if (local->nb_blocks != nb_remote_blocks) {
3238 ERROR(errp, "ram blocks mismatch #1! "
3239 "Your QEMU command line parameters are probably "
3240 "not identical on both the source and destination.");
3241 return -EINVAL;
3242 }
3243
3244 qemu_rdma_move_header(rdma, reg_result_idx, &resp);
3245 memcpy(rdma->block,
3246 rdma->wr_data[reg_result_idx].control_curr, resp.len);
3247 for (i = 0; i < nb_remote_blocks; i++) {
3248 network_to_remote_block(&rdma->block[i]);
3249
3250 /* search local ram blocks */
3251 for (j = 0; j < local->nb_blocks; j++) {
3252 if (rdma->block[i].offset != local->block[j].offset) {
3253 continue;
3254 }
3255
3256 if (rdma->block[i].length != local->block[j].length) {
3257 ERROR(errp, "ram blocks mismatch #2! "
3258 "Your QEMU command line parameters are probably "
3259 "not identical on both the source and destination.");
3260 return -EINVAL;
3261 }
3262 local->block[j].remote_host_addr =
3263 rdma->block[i].remote_host_addr;
3264 local->block[j].remote_rkey = rdma->block[i].remote_rkey;
3265 break;
3266 }
3267
3268 if (j >= local->nb_blocks) {
3269 ERROR(errp, "ram blocks mismatch #3! "
3270 "Your QEMU command line parameters are probably "
3271 "not identical on both the source and destination.");
3272 return -EINVAL;
3273 }
3274 }
3275 }
3276
3277 DDDPRINTF("Sending registration finish %" PRIu64 "...\n", flags);
3278
3279 head.type = RDMA_CONTROL_REGISTER_FINISHED;
3280 ret = qemu_rdma_exchange_send(rdma, &head, NULL, NULL, NULL, NULL);
3281
3282 if (ret < 0) {
3283 goto err;
3284 }
3285
3286 return 0;
3287 err:
3288 rdma->error_state = ret;
3289 return ret;
3290 }
3291
3292 static int qemu_rdma_get_fd(void *opaque)
3293 {
3294 QEMUFileRDMA *rfile = opaque;
3295 RDMAContext *rdma = rfile->rdma;
3296
3297 return rdma->comp_channel->fd;
3298 }
3299
3300 const QEMUFileOps rdma_read_ops = {
3301 .get_buffer = qemu_rdma_get_buffer,
3302 .get_fd = qemu_rdma_get_fd,
3303 .close = qemu_rdma_close,
3304 .hook_ram_load = qemu_rdma_registration_handle,
3305 };
3306
3307 const QEMUFileOps rdma_write_ops = {
3308 .put_buffer = qemu_rdma_put_buffer,
3309 .close = qemu_rdma_close,
3310 .before_ram_iterate = qemu_rdma_registration_start,
3311 .after_ram_iterate = qemu_rdma_registration_stop,
3312 .save_page = qemu_rdma_save_page,
3313 };
3314
3315 static void *qemu_fopen_rdma(RDMAContext *rdma, const char *mode)
3316 {
3317 QEMUFileRDMA *r = g_malloc0(sizeof(QEMUFileRDMA));
3318
3319 if (qemu_file_mode_is_not_valid(mode)) {
3320 return NULL;
3321 }
3322
3323 r->rdma = rdma;
3324
3325 if (mode[0] == 'w') {
3326 r->file = qemu_fopen_ops(r, &rdma_write_ops);
3327 } else {
3328 r->file = qemu_fopen_ops(r, &rdma_read_ops);
3329 }
3330
3331 return r->file;
3332 }
3333
3334 static void rdma_accept_incoming_migration(void *opaque)
3335 {
3336 RDMAContext *rdma = opaque;
3337 int ret;
3338 QEMUFile *f;
3339 Error *local_err = NULL, **errp = &local_err;
3340
3341 DPRINTF("Accepting rdma connection...\n");
3342 ret = qemu_rdma_accept(rdma);
3343
3344 if (ret) {
3345 ERROR(errp, "RDMA Migration initialization failed!");
3346 return;
3347 }
3348
3349 DPRINTF("Accepted migration\n");
3350
3351 f = qemu_fopen_rdma(rdma, "rb");
3352 if (f == NULL) {
3353 ERROR(errp, "could not qemu_fopen_rdma!");
3354 qemu_rdma_cleanup(rdma);
3355 return;
3356 }
3357
3358 rdma->migration_started_on_destination = 1;
3359 process_incoming_migration(f);
3360 }
3361
3362 void rdma_start_incoming_migration(const char *host_port, Error **errp)
3363 {
3364 int ret;
3365 RDMAContext *rdma;
3366 Error *local_err = NULL;
3367
3368 DPRINTF("Starting RDMA-based incoming migration\n");
3369 rdma = qemu_rdma_data_init(host_port, &local_err);
3370
3371 if (rdma == NULL) {
3372 goto err;
3373 }
3374
3375 ret = qemu_rdma_dest_init(rdma, &local_err);
3376
3377 if (ret) {
3378 goto err;
3379 }
3380
3381 DPRINTF("qemu_rdma_dest_init success\n");
3382
3383 ret = rdma_listen(rdma->listen_id, 5);
3384
3385 if (ret) {
3386 ERROR(errp, "listening on socket!");
3387 goto err;
3388 }
3389
3390 DPRINTF("rdma_listen success\n");
3391
3392 qemu_set_fd_handler2(rdma->channel->fd, NULL,
3393 rdma_accept_incoming_migration, NULL,
3394 (void *)(intptr_t) rdma);
3395 return;
3396 err:
3397 error_propagate(errp, local_err);
3398 g_free(rdma);
3399 }
3400
3401 void rdma_start_outgoing_migration(void *opaque,
3402 const char *host_port, Error **errp)
3403 {
3404 MigrationState *s = opaque;
3405 Error *local_err = NULL, **temp = &local_err;
3406 RDMAContext *rdma = qemu_rdma_data_init(host_port, &local_err);
3407 int ret = 0;
3408
3409 if (rdma == NULL) {
3410 ERROR(temp, "Failed to initialize RDMA data structures! %d", ret);
3411 goto err;
3412 }
3413
3414 ret = qemu_rdma_source_init(rdma, &local_err,
3415 s->enabled_capabilities[MIGRATION_CAPABILITY_RDMA_PIN_ALL]);
3416
3417 if (ret) {
3418 goto err;
3419 }
3420
3421 DPRINTF("qemu_rdma_source_init success\n");
3422 ret = qemu_rdma_connect(rdma, &local_err);
3423
3424 if (ret) {
3425 goto err;
3426 }
3427
3428 DPRINTF("qemu_rdma_source_connect success\n");