1 | /* |
2 | * QEMU System Emulator |
3 | * |
4 | * Copyright (c) 2003-2008 Fabrice Bellard |
5 | * Copyright (c) 2011-2015 Red Hat Inc |
6 | * |
7 | * Authors: |
8 | * Juan Quintela <quintela@redhat.com> |
9 | * |
10 | * Permission is hereby granted, free of charge, to any person obtaining a copy |
11 | * of this software and associated documentation files (the "Software"), to deal |
12 | * in the Software without restriction, including without limitation the rights |
13 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
14 | * copies of the Software, and to permit persons to whom the Software is |
15 | * furnished to do so, subject to the following conditions: |
16 | * |
17 | * The above copyright notice and this permission notice shall be included in |
18 | * all copies or substantial portions of the Software. |
19 | * |
20 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
21 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
22 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
23 | * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
24 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
25 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
26 | * THE SOFTWARE. |
27 | */ |
28 | |
29 | #include "qemu/osdep.h" |
30 | #include "cpu.h" |
31 | #include <zlib.h> |
32 | #include "qemu/cutils.h" |
33 | #include "qemu/bitops.h" |
34 | #include "qemu/bitmap.h" |
35 | #include "qemu/main-loop.h" |
36 | #include "qemu/pmem.h" |
37 | #include "xbzrle.h" |
38 | #include "ram.h" |
39 | #include "migration.h" |
40 | #include "socket.h" |
41 | #include "migration/register.h" |
42 | #include "migration/misc.h" |
43 | #include "qemu-file.h" |
44 | #include "postcopy-ram.h" |
45 | #include "page_cache.h" |
46 | #include "qemu/error-report.h" |
47 | #include "qapi/error.h" |
48 | #include "qapi/qapi-events-migration.h" |
49 | #include "qapi/qmp/qerror.h" |
50 | #include "trace.h" |
51 | #include "exec/ram_addr.h" |
52 | #include "exec/target_page.h" |
53 | #include "qemu/rcu_queue.h" |
54 | #include "migration/colo.h" |
55 | #include "block.h" |
56 | #include "sysemu/sysemu.h" |
57 | #include "qemu/uuid.h" |
58 | #include "savevm.h" |
59 | #include "qemu/iov.h" |
60 | |
61 | /***********************************************************/ |
62 | /* ram save/restore */ |
63 | |
64 | /* RAM_SAVE_FLAG_ZERO used to be named RAM_SAVE_FLAG_COMPRESS, it |
65 | * worked for pages that where filled with the same char. We switched |
66 | * it to only search for the zero value. And to avoid confusion with |
67 | * RAM_SSAVE_FLAG_COMPRESS_PAGE just rename it. |
68 | */ |
69 | |
70 | #define RAM_SAVE_FLAG_FULL 0x01 /* Obsolete, not used anymore */ |
71 | #define RAM_SAVE_FLAG_ZERO 0x02 |
72 | #define RAM_SAVE_FLAG_MEM_SIZE 0x04 |
73 | #define RAM_SAVE_FLAG_PAGE 0x08 |
74 | #define RAM_SAVE_FLAG_EOS 0x10 |
75 | #define RAM_SAVE_FLAG_CONTINUE 0x20 |
76 | #define RAM_SAVE_FLAG_XBZRLE 0x40 |
77 | /* 0x80 is reserved in migration.h start with 0x100 next */ |
78 | #define RAM_SAVE_FLAG_COMPRESS_PAGE 0x100 |
79 | |
80 | static inline bool is_zero_range(uint8_t *p, uint64_t size) |
81 | { |
82 | return buffer_is_zero(p, size); |
83 | } |
84 | |
85 | XBZRLECacheStats xbzrle_counters; |
86 | |
87 | /* struct contains XBZRLE cache and a static page |
88 | used by the compression */ |
89 | static struct { |
90 | /* buffer used for XBZRLE encoding */ |
91 | uint8_t *encoded_buf; |
92 | /* buffer for storing page content */ |
93 | uint8_t *current_buf; |
94 | /* Cache for XBZRLE, Protected by lock. */ |
95 | PageCache *cache; |
96 | QemuMutex lock; |
97 | /* it will store a page full of zeros */ |
98 | uint8_t *zero_target_page; |
99 | /* buffer used for XBZRLE decoding */ |
100 | uint8_t *decoded_buf; |
101 | } XBZRLE; |
102 | |
103 | static void XBZRLE_cache_lock(void) |
104 | { |
105 | if (migrate_use_xbzrle()) |
106 | qemu_mutex_lock(&XBZRLE.lock); |
107 | } |
108 | |
109 | static void XBZRLE_cache_unlock(void) |
110 | { |
111 | if (migrate_use_xbzrle()) |
112 | qemu_mutex_unlock(&XBZRLE.lock); |
113 | } |
114 | |
115 | /** |
116 | * xbzrle_cache_resize: resize the xbzrle cache |
117 | * |
118 | * This function is called from qmp_migrate_set_cache_size in main |
119 | * thread, possibly while a migration is in progress. A running |
120 | * migration may be using the cache and might finish during this call, |
121 | * hence changes to the cache are protected by XBZRLE.lock(). |
122 | * |
123 | * Returns 0 for success or -1 for error |
124 | * |
125 | * @new_size: new cache size |
126 | * @errp: set *errp if the check failed, with reason |
127 | */ |
128 | int xbzrle_cache_resize(int64_t new_size, Error **errp) |
129 | { |
130 | PageCache *new_cache; |
131 | int64_t ret = 0; |
132 | |
133 | /* Check for truncation */ |
134 | if (new_size != (size_t)new_size) { |
135 | error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "cache size" , |
136 | "exceeding address space" ); |
137 | return -1; |
138 | } |
139 | |
140 | if (new_size == migrate_xbzrle_cache_size()) { |
141 | /* nothing to do */ |
142 | return 0; |
143 | } |
144 | |
145 | XBZRLE_cache_lock(); |
146 | |
147 | if (XBZRLE.cache != NULL) { |
148 | new_cache = cache_init(new_size, TARGET_PAGE_SIZE, errp); |
149 | if (!new_cache) { |
150 | ret = -1; |
151 | goto out; |
152 | } |
153 | |
154 | cache_fini(XBZRLE.cache); |
155 | XBZRLE.cache = new_cache; |
156 | } |
157 | out: |
158 | XBZRLE_cache_unlock(); |
159 | return ret; |
160 | } |
161 | |
162 | static bool ramblock_is_ignored(RAMBlock *block) |
163 | { |
164 | return !qemu_ram_is_migratable(block) || |
165 | (migrate_ignore_shared() && qemu_ram_is_shared(block)); |
166 | } |
167 | |
168 | /* Should be holding either ram_list.mutex, or the RCU lock. */ |
169 | #define RAMBLOCK_FOREACH_NOT_IGNORED(block) \ |
170 | INTERNAL_RAMBLOCK_FOREACH(block) \ |
171 | if (ramblock_is_ignored(block)) {} else |
172 | |
173 | #define RAMBLOCK_FOREACH_MIGRATABLE(block) \ |
174 | INTERNAL_RAMBLOCK_FOREACH(block) \ |
175 | if (!qemu_ram_is_migratable(block)) {} else |
176 | |
177 | #undef RAMBLOCK_FOREACH |
178 | |
179 | int foreach_not_ignored_block(RAMBlockIterFunc func, void *opaque) |
180 | { |
181 | RAMBlock *block; |
182 | int ret = 0; |
183 | |
184 | rcu_read_lock(); |
185 | RAMBLOCK_FOREACH_NOT_IGNORED(block) { |
186 | ret = func(block, opaque); |
187 | if (ret) { |
188 | break; |
189 | } |
190 | } |
191 | rcu_read_unlock(); |
192 | return ret; |
193 | } |
194 | |
195 | static void ramblock_recv_map_init(void) |
196 | { |
197 | RAMBlock *rb; |
198 | |
199 | RAMBLOCK_FOREACH_NOT_IGNORED(rb) { |
200 | assert(!rb->receivedmap); |
201 | rb->receivedmap = bitmap_new(rb->max_length >> qemu_target_page_bits()); |
202 | } |
203 | } |
204 | |
205 | int ramblock_recv_bitmap_test(RAMBlock *rb, void *host_addr) |
206 | { |
207 | return test_bit(ramblock_recv_bitmap_offset(host_addr, rb), |
208 | rb->receivedmap); |
209 | } |
210 | |
211 | bool ramblock_recv_bitmap_test_byte_offset(RAMBlock *rb, uint64_t byte_offset) |
212 | { |
213 | return test_bit(byte_offset >> TARGET_PAGE_BITS, rb->receivedmap); |
214 | } |
215 | |
216 | void ramblock_recv_bitmap_set(RAMBlock *rb, void *host_addr) |
217 | { |
218 | set_bit_atomic(ramblock_recv_bitmap_offset(host_addr, rb), rb->receivedmap); |
219 | } |
220 | |
221 | void ramblock_recv_bitmap_set_range(RAMBlock *rb, void *host_addr, |
222 | size_t nr) |
223 | { |
224 | bitmap_set_atomic(rb->receivedmap, |
225 | ramblock_recv_bitmap_offset(host_addr, rb), |
226 | nr); |
227 | } |
228 | |
229 | #define RAMBLOCK_RECV_BITMAP_ENDING (0x0123456789abcdefULL) |
230 | |
231 | /* |
232 | * Format: bitmap_size (8 bytes) + whole_bitmap (N bytes). |
233 | * |
234 | * Returns >0 if success with sent bytes, or <0 if error. |
235 | */ |
236 | int64_t ramblock_recv_bitmap_send(QEMUFile *file, |
237 | const char *block_name) |
238 | { |
239 | RAMBlock *block = qemu_ram_block_by_name(block_name); |
240 | unsigned long *le_bitmap, nbits; |
241 | uint64_t size; |
242 | |
243 | if (!block) { |
244 | error_report("%s: invalid block name: %s" , __func__, block_name); |
245 | return -1; |
246 | } |
247 | |
248 | nbits = block->used_length >> TARGET_PAGE_BITS; |
249 | |
250 | /* |
251 | * Make sure the tmp bitmap buffer is big enough, e.g., on 32bit |
252 | * machines we may need 4 more bytes for padding (see below |
253 | * comment). So extend it a bit before hand. |
254 | */ |
255 | le_bitmap = bitmap_new(nbits + BITS_PER_LONG); |
256 | |
257 | /* |
258 | * Always use little endian when sending the bitmap. This is |
259 | * required that when source and destination VMs are not using the |
260 | * same endianess. (Note: big endian won't work.) |
261 | */ |
262 | bitmap_to_le(le_bitmap, block->receivedmap, nbits); |
263 | |
264 | /* Size of the bitmap, in bytes */ |
265 | size = DIV_ROUND_UP(nbits, 8); |
266 | |
267 | /* |
268 | * size is always aligned to 8 bytes for 64bit machines, but it |
269 | * may not be true for 32bit machines. We need this padding to |
270 | * make sure the migration can survive even between 32bit and |
271 | * 64bit machines. |
272 | */ |
273 | size = ROUND_UP(size, 8); |
274 | |
275 | qemu_put_be64(file, size); |
276 | qemu_put_buffer(file, (const uint8_t *)le_bitmap, size); |
277 | /* |
278 | * Mark as an end, in case the middle part is screwed up due to |
279 | * some "misterious" reason. |
280 | */ |
281 | qemu_put_be64(file, RAMBLOCK_RECV_BITMAP_ENDING); |
282 | qemu_fflush(file); |
283 | |
284 | g_free(le_bitmap); |
285 | |
286 | if (qemu_file_get_error(file)) { |
287 | return qemu_file_get_error(file); |
288 | } |
289 | |
290 | return size + sizeof(size); |
291 | } |
292 | |
293 | /* |
294 | * An outstanding page request, on the source, having been received |
295 | * and queued |
296 | */ |
297 | struct { |
298 | RAMBlock *; |
299 | hwaddr ; |
300 | hwaddr ; |
301 | |
302 | QSIMPLEQ_ENTRY(RAMSrcPageRequest) ; |
303 | }; |
304 | |
305 | /* State of RAM for migration */ |
306 | struct RAMState { |
307 | /* QEMUFile used for this migration */ |
308 | QEMUFile *f; |
309 | /* Last block that we have visited searching for dirty pages */ |
310 | RAMBlock *last_seen_block; |
311 | /* Last block from where we have sent data */ |
312 | RAMBlock *last_sent_block; |
313 | /* Last dirty target page we have sent */ |
314 | ram_addr_t last_page; |
315 | /* last ram version we have seen */ |
316 | uint32_t last_version; |
317 | /* We are in the first round */ |
318 | bool ram_bulk_stage; |
319 | /* The free page optimization is enabled */ |
320 | bool fpo_enabled; |
321 | /* How many times we have dirty too many pages */ |
322 | int dirty_rate_high_cnt; |
323 | /* these variables are used for bitmap sync */ |
324 | /* last time we did a full bitmap_sync */ |
325 | int64_t time_last_bitmap_sync; |
326 | /* bytes transferred at start_time */ |
327 | uint64_t bytes_xfer_prev; |
328 | /* number of dirty pages since start_time */ |
329 | uint64_t num_dirty_pages_period; |
330 | /* xbzrle misses since the beginning of the period */ |
331 | uint64_t xbzrle_cache_miss_prev; |
332 | |
333 | /* compression statistics since the beginning of the period */ |
334 | /* amount of count that no free thread to compress data */ |
335 | uint64_t compress_thread_busy_prev; |
336 | /* amount bytes after compression */ |
337 | uint64_t compressed_size_prev; |
338 | /* amount of compressed pages */ |
339 | uint64_t compress_pages_prev; |
340 | |
341 | /* total handled target pages at the beginning of period */ |
342 | uint64_t target_page_count_prev; |
343 | /* total handled target pages since start */ |
344 | uint64_t target_page_count; |
345 | /* number of dirty bits in the bitmap */ |
346 | uint64_t migration_dirty_pages; |
347 | /* Protects modification of the bitmap and migration dirty pages */ |
348 | QemuMutex bitmap_mutex; |
349 | /* The RAMBlock used in the last src_page_requests */ |
350 | RAMBlock *last_req_rb; |
351 | /* Queue of outstanding page requests from the destination */ |
352 | QemuMutex src_page_req_mutex; |
353 | QSIMPLEQ_HEAD(, RAMSrcPageRequest) src_page_requests; |
354 | }; |
355 | typedef struct RAMState RAMState; |
356 | |
357 | static RAMState *ram_state; |
358 | |
359 | static NotifierWithReturnList precopy_notifier_list; |
360 | |
361 | void precopy_infrastructure_init(void) |
362 | { |
363 | notifier_with_return_list_init(&precopy_notifier_list); |
364 | } |
365 | |
366 | void precopy_add_notifier(NotifierWithReturn *n) |
367 | { |
368 | notifier_with_return_list_add(&precopy_notifier_list, n); |
369 | } |
370 | |
371 | void precopy_remove_notifier(NotifierWithReturn *n) |
372 | { |
373 | notifier_with_return_remove(n); |
374 | } |
375 | |
376 | int precopy_notify(PrecopyNotifyReason reason, Error **errp) |
377 | { |
378 | PrecopyNotifyData pnd; |
379 | pnd.reason = reason; |
380 | pnd.errp = errp; |
381 | |
382 | return notifier_with_return_list_notify(&precopy_notifier_list, &pnd); |
383 | } |
384 | |
385 | void precopy_enable_free_page_optimization(void) |
386 | { |
387 | if (!ram_state) { |
388 | return; |
389 | } |
390 | |
391 | ram_state->fpo_enabled = true; |
392 | } |
393 | |
394 | uint64_t ram_bytes_remaining(void) |
395 | { |
396 | return ram_state ? (ram_state->migration_dirty_pages * TARGET_PAGE_SIZE) : |
397 | 0; |
398 | } |
399 | |
400 | MigrationStats ram_counters; |
401 | |
402 | /* used by the search for pages to send */ |
403 | struct PageSearchStatus { |
404 | /* Current block being searched */ |
405 | RAMBlock *block; |
406 | /* Current page to search from */ |
407 | unsigned long page; |
408 | /* Set once we wrap around */ |
409 | bool complete_round; |
410 | }; |
411 | typedef struct PageSearchStatus PageSearchStatus; |
412 | |
413 | CompressionStats compression_counters; |
414 | |
415 | struct CompressParam { |
416 | bool done; |
417 | bool quit; |
418 | bool zero_page; |
419 | QEMUFile *file; |
420 | QemuMutex mutex; |
421 | QemuCond cond; |
422 | RAMBlock *block; |
423 | ram_addr_t offset; |
424 | |
425 | /* internally used fields */ |
426 | z_stream stream; |
427 | uint8_t *originbuf; |
428 | }; |
429 | typedef struct CompressParam CompressParam; |
430 | |
431 | struct DecompressParam { |
432 | bool done; |
433 | bool quit; |
434 | QemuMutex mutex; |
435 | QemuCond cond; |
436 | void *des; |
437 | uint8_t *compbuf; |
438 | int len; |
439 | z_stream stream; |
440 | }; |
441 | typedef struct DecompressParam DecompressParam; |
442 | |
443 | static CompressParam *comp_param; |
444 | static QemuThread *compress_threads; |
445 | /* comp_done_cond is used to wake up the migration thread when |
446 | * one of the compression threads has finished the compression. |
447 | * comp_done_lock is used to co-work with comp_done_cond. |
448 | */ |
449 | static QemuMutex comp_done_lock; |
450 | static QemuCond comp_done_cond; |
451 | /* The empty QEMUFileOps will be used by file in CompressParam */ |
452 | static const QEMUFileOps empty_ops = { }; |
453 | |
454 | static QEMUFile *decomp_file; |
455 | static DecompressParam *decomp_param; |
456 | static QemuThread *decompress_threads; |
457 | static QemuMutex decomp_done_lock; |
458 | static QemuCond decomp_done_cond; |
459 | |
460 | static bool do_compress_ram_page(QEMUFile *f, z_stream *stream, RAMBlock *block, |
461 | ram_addr_t offset, uint8_t *source_buf); |
462 | |
463 | static void *do_data_compress(void *opaque) |
464 | { |
465 | CompressParam *param = opaque; |
466 | RAMBlock *block; |
467 | ram_addr_t offset; |
468 | bool zero_page; |
469 | |
470 | qemu_mutex_lock(¶m->mutex); |
471 | while (!param->quit) { |
472 | if (param->block) { |
473 | block = param->block; |
474 | offset = param->offset; |
475 | param->block = NULL; |
476 | qemu_mutex_unlock(¶m->mutex); |
477 | |
478 | zero_page = do_compress_ram_page(param->file, ¶m->stream, |
479 | block, offset, param->originbuf); |
480 | |
481 | qemu_mutex_lock(&comp_done_lock); |
482 | param->done = true; |
483 | param->zero_page = zero_page; |
484 | qemu_cond_signal(&comp_done_cond); |
485 | qemu_mutex_unlock(&comp_done_lock); |
486 | |
487 | qemu_mutex_lock(¶m->mutex); |
488 | } else { |
489 | qemu_cond_wait(¶m->cond, ¶m->mutex); |
490 | } |
491 | } |
492 | qemu_mutex_unlock(¶m->mutex); |
493 | |
494 | return NULL; |
495 | } |
496 | |
497 | static void compress_threads_save_cleanup(void) |
498 | { |
499 | int i, thread_count; |
500 | |
501 | if (!migrate_use_compression() || !comp_param) { |
502 | return; |
503 | } |
504 | |
505 | thread_count = migrate_compress_threads(); |
506 | for (i = 0; i < thread_count; i++) { |
507 | /* |
508 | * we use it as a indicator which shows if the thread is |
509 | * properly init'd or not |
510 | */ |
511 | if (!comp_param[i].file) { |
512 | break; |
513 | } |
514 | |
515 | qemu_mutex_lock(&comp_param[i].mutex); |
516 | comp_param[i].quit = true; |
517 | qemu_cond_signal(&comp_param[i].cond); |
518 | qemu_mutex_unlock(&comp_param[i].mutex); |
519 | |
520 | qemu_thread_join(compress_threads + i); |
521 | qemu_mutex_destroy(&comp_param[i].mutex); |
522 | qemu_cond_destroy(&comp_param[i].cond); |
523 | deflateEnd(&comp_param[i].stream); |
524 | g_free(comp_param[i].originbuf); |
525 | qemu_fclose(comp_param[i].file); |
526 | comp_param[i].file = NULL; |
527 | } |
528 | qemu_mutex_destroy(&comp_done_lock); |
529 | qemu_cond_destroy(&comp_done_cond); |
530 | g_free(compress_threads); |
531 | g_free(comp_param); |
532 | compress_threads = NULL; |
533 | comp_param = NULL; |
534 | } |
535 | |
536 | static int compress_threads_save_setup(void) |
537 | { |
538 | int i, thread_count; |
539 | |
540 | if (!migrate_use_compression()) { |
541 | return 0; |
542 | } |
543 | thread_count = migrate_compress_threads(); |
544 | compress_threads = g_new0(QemuThread, thread_count); |
545 | comp_param = g_new0(CompressParam, thread_count); |
546 | qemu_cond_init(&comp_done_cond); |
547 | qemu_mutex_init(&comp_done_lock); |
548 | for (i = 0; i < thread_count; i++) { |
549 | comp_param[i].originbuf = g_try_malloc(TARGET_PAGE_SIZE); |
550 | if (!comp_param[i].originbuf) { |
551 | goto exit; |
552 | } |
553 | |
554 | if (deflateInit(&comp_param[i].stream, |
555 | migrate_compress_level()) != Z_OK) { |
556 | g_free(comp_param[i].originbuf); |
557 | goto exit; |
558 | } |
559 | |
560 | /* comp_param[i].file is just used as a dummy buffer to save data, |
561 | * set its ops to empty. |
562 | */ |
563 | comp_param[i].file = qemu_fopen_ops(NULL, &empty_ops); |
564 | comp_param[i].done = true; |
565 | comp_param[i].quit = false; |
566 | qemu_mutex_init(&comp_param[i].mutex); |
567 | qemu_cond_init(&comp_param[i].cond); |
568 | qemu_thread_create(compress_threads + i, "compress" , |
569 | do_data_compress, comp_param + i, |
570 | QEMU_THREAD_JOINABLE); |
571 | } |
572 | return 0; |
573 | |
574 | exit: |
575 | compress_threads_save_cleanup(); |
576 | return -1; |
577 | } |
578 | |
579 | /* Multiple fd's */ |
580 | |
581 | #define MULTIFD_MAGIC 0x11223344U |
582 | #define MULTIFD_VERSION 1 |
583 | |
584 | #define MULTIFD_FLAG_SYNC (1 << 0) |
585 | |
586 | /* This value needs to be a multiple of qemu_target_page_size() */ |
587 | #define MULTIFD_PACKET_SIZE (512 * 1024) |
588 | |
589 | typedef struct { |
590 | uint32_t magic; |
591 | uint32_t version; |
592 | unsigned char uuid[16]; /* QemuUUID */ |
593 | uint8_t id; |
594 | uint8_t unused1[7]; /* Reserved for future use */ |
595 | uint64_t unused2[4]; /* Reserved for future use */ |
596 | } __attribute__((packed)) MultiFDInit_t; |
597 | |
598 | typedef struct { |
599 | uint32_t magic; |
600 | uint32_t version; |
601 | uint32_t flags; |
602 | /* maximum number of allocated pages */ |
603 | uint32_t pages_alloc; |
604 | uint32_t pages_used; |
605 | /* size of the next packet that contains pages */ |
606 | uint32_t next_packet_size; |
607 | uint64_t packet_num; |
608 | uint64_t unused[4]; /* Reserved for future use */ |
609 | char ramblock[256]; |
610 | uint64_t offset[]; |
611 | } __attribute__((packed)) MultiFDPacket_t; |
612 | |
613 | typedef struct { |
614 | /* number of used pages */ |
615 | uint32_t used; |
616 | /* number of allocated pages */ |
617 | uint32_t allocated; |
618 | /* global number of generated multifd packets */ |
619 | uint64_t packet_num; |
620 | /* offset of each page */ |
621 | ram_addr_t *offset; |
622 | /* pointer to each page */ |
623 | struct iovec *iov; |
624 | RAMBlock *block; |
625 | } MultiFDPages_t; |
626 | |
627 | typedef struct { |
628 | /* this fields are not changed once the thread is created */ |
629 | /* channel number */ |
630 | uint8_t id; |
631 | /* channel thread name */ |
632 | char *name; |
633 | /* channel thread id */ |
634 | QemuThread thread; |
635 | /* communication channel */ |
636 | QIOChannel *c; |
637 | /* sem where to wait for more work */ |
638 | QemuSemaphore sem; |
639 | /* this mutex protects the following parameters */ |
640 | QemuMutex mutex; |
641 | /* is this channel thread running */ |
642 | bool running; |
643 | /* should this thread finish */ |
644 | bool quit; |
645 | /* thread has work to do */ |
646 | int pending_job; |
647 | /* array of pages to sent */ |
648 | MultiFDPages_t *pages; |
649 | /* packet allocated len */ |
650 | uint32_t packet_len; |
651 | /* pointer to the packet */ |
652 | MultiFDPacket_t *packet; |
653 | /* multifd flags for each packet */ |
654 | uint32_t flags; |
655 | /* size of the next packet that contains pages */ |
656 | uint32_t next_packet_size; |
657 | /* global number of generated multifd packets */ |
658 | uint64_t packet_num; |
659 | /* thread local variables */ |
660 | /* packets sent through this channel */ |
661 | uint64_t num_packets; |
662 | /* pages sent through this channel */ |
663 | uint64_t num_pages; |
664 | /* syncs main thread and channels */ |
665 | QemuSemaphore sem_sync; |
666 | } MultiFDSendParams; |
667 | |
668 | typedef struct { |
669 | /* this fields are not changed once the thread is created */ |
670 | /* channel number */ |
671 | uint8_t id; |
672 | /* channel thread name */ |
673 | char *name; |
674 | /* channel thread id */ |
675 | QemuThread thread; |
676 | /* communication channel */ |
677 | QIOChannel *c; |
678 | /* this mutex protects the following parameters */ |
679 | QemuMutex mutex; |
680 | /* is this channel thread running */ |
681 | bool running; |
682 | /* should this thread finish */ |
683 | bool quit; |
684 | /* array of pages to receive */ |
685 | MultiFDPages_t *pages; |
686 | /* packet allocated len */ |
687 | uint32_t packet_len; |
688 | /* pointer to the packet */ |
689 | MultiFDPacket_t *packet; |
690 | /* multifd flags for each packet */ |
691 | uint32_t flags; |
692 | /* global number of generated multifd packets */ |
693 | uint64_t packet_num; |
694 | /* thread local variables */ |
695 | /* size of the next packet that contains pages */ |
696 | uint32_t next_packet_size; |
697 | /* packets sent through this channel */ |
698 | uint64_t num_packets; |
699 | /* pages sent through this channel */ |
700 | uint64_t num_pages; |
701 | /* syncs main thread and channels */ |
702 | QemuSemaphore sem_sync; |
703 | } MultiFDRecvParams; |
704 | |
705 | static int multifd_send_initial_packet(MultiFDSendParams *p, Error **errp) |
706 | { |
707 | MultiFDInit_t msg; |
708 | int ret; |
709 | |
710 | msg.magic = cpu_to_be32(MULTIFD_MAGIC); |
711 | msg.version = cpu_to_be32(MULTIFD_VERSION); |
712 | msg.id = p->id; |
713 | memcpy(msg.uuid, &qemu_uuid.data, sizeof(msg.uuid)); |
714 | |
715 | ret = qio_channel_write_all(p->c, (char *)&msg, sizeof(msg), errp); |
716 | if (ret != 0) { |
717 | return -1; |
718 | } |
719 | return 0; |
720 | } |
721 | |
722 | static int multifd_recv_initial_packet(QIOChannel *c, Error **errp) |
723 | { |
724 | MultiFDInit_t msg; |
725 | int ret; |
726 | |
727 | ret = qio_channel_read_all(c, (char *)&msg, sizeof(msg), errp); |
728 | if (ret != 0) { |
729 | return -1; |
730 | } |
731 | |
732 | msg.magic = be32_to_cpu(msg.magic); |
733 | msg.version = be32_to_cpu(msg.version); |
734 | |
735 | if (msg.magic != MULTIFD_MAGIC) { |
736 | error_setg(errp, "multifd: received packet magic %x " |
737 | "expected %x" , msg.magic, MULTIFD_MAGIC); |
738 | return -1; |
739 | } |
740 | |
741 | if (msg.version != MULTIFD_VERSION) { |
742 | error_setg(errp, "multifd: received packet version %d " |
743 | "expected %d" , msg.version, MULTIFD_VERSION); |
744 | return -1; |
745 | } |
746 | |
747 | if (memcmp(msg.uuid, &qemu_uuid, sizeof(qemu_uuid))) { |
748 | char *uuid = qemu_uuid_unparse_strdup(&qemu_uuid); |
749 | char *msg_uuid = qemu_uuid_unparse_strdup((const QemuUUID *)msg.uuid); |
750 | |
751 | error_setg(errp, "multifd: received uuid '%s' and expected " |
752 | "uuid '%s' for channel %hhd" , msg_uuid, uuid, msg.id); |
753 | g_free(uuid); |
754 | g_free(msg_uuid); |
755 | return -1; |
756 | } |
757 | |
758 | if (msg.id > migrate_multifd_channels()) { |
759 | error_setg(errp, "multifd: received channel version %d " |
760 | "expected %d" , msg.version, MULTIFD_VERSION); |
761 | return -1; |
762 | } |
763 | |
764 | return msg.id; |
765 | } |
766 | |
767 | static MultiFDPages_t *multifd_pages_init(size_t size) |
768 | { |
769 | MultiFDPages_t *pages = g_new0(MultiFDPages_t, 1); |
770 | |
771 | pages->allocated = size; |
772 | pages->iov = g_new0(struct iovec, size); |
773 | pages->offset = g_new0(ram_addr_t, size); |
774 | |
775 | return pages; |
776 | } |
777 | |
778 | static void multifd_pages_clear(MultiFDPages_t *pages) |
779 | { |
780 | pages->used = 0; |
781 | pages->allocated = 0; |
782 | pages->packet_num = 0; |
783 | pages->block = NULL; |
784 | g_free(pages->iov); |
785 | pages->iov = NULL; |
786 | g_free(pages->offset); |
787 | pages->offset = NULL; |
788 | g_free(pages); |
789 | } |
790 | |
791 | static void multifd_send_fill_packet(MultiFDSendParams *p) |
792 | { |
793 | MultiFDPacket_t *packet = p->packet; |
794 | uint32_t page_max = MULTIFD_PACKET_SIZE / qemu_target_page_size(); |
795 | int i; |
796 | |
797 | packet->magic = cpu_to_be32(MULTIFD_MAGIC); |
798 | packet->version = cpu_to_be32(MULTIFD_VERSION); |
799 | packet->flags = cpu_to_be32(p->flags); |
800 | packet->pages_alloc = cpu_to_be32(page_max); |
801 | packet->pages_used = cpu_to_be32(p->pages->used); |
802 | packet->next_packet_size = cpu_to_be32(p->next_packet_size); |
803 | packet->packet_num = cpu_to_be64(p->packet_num); |
804 | |
805 | if (p->pages->block) { |
806 | strncpy(packet->ramblock, p->pages->block->idstr, 256); |
807 | } |
808 | |
809 | for (i = 0; i < p->pages->used; i++) { |
810 | packet->offset[i] = cpu_to_be64(p->pages->offset[i]); |
811 | } |
812 | } |
813 | |
814 | static int multifd_recv_unfill_packet(MultiFDRecvParams *p, Error **errp) |
815 | { |
816 | MultiFDPacket_t *packet = p->packet; |
817 | uint32_t pages_max = MULTIFD_PACKET_SIZE / qemu_target_page_size(); |
818 | RAMBlock *block; |
819 | int i; |
820 | |
821 | packet->magic = be32_to_cpu(packet->magic); |
822 | if (packet->magic != MULTIFD_MAGIC) { |
823 | error_setg(errp, "multifd: received packet " |
824 | "magic %x and expected magic %x" , |
825 | packet->magic, MULTIFD_MAGIC); |
826 | return -1; |
827 | } |
828 | |
829 | packet->version = be32_to_cpu(packet->version); |
830 | if (packet->version != MULTIFD_VERSION) { |
831 | error_setg(errp, "multifd: received packet " |
832 | "version %d and expected version %d" , |
833 | packet->version, MULTIFD_VERSION); |
834 | return -1; |
835 | } |
836 | |
837 | p->flags = be32_to_cpu(packet->flags); |
838 | |
839 | packet->pages_alloc = be32_to_cpu(packet->pages_alloc); |
840 | /* |
841 | * If we recevied a packet that is 100 times bigger than expected |
842 | * just stop migration. It is a magic number. |
843 | */ |
844 | if (packet->pages_alloc > pages_max * 100) { |
845 | error_setg(errp, "multifd: received packet " |
846 | "with size %d and expected a maximum size of %d" , |
847 | packet->pages_alloc, pages_max * 100) ; |
848 | return -1; |
849 | } |
850 | /* |
851 | * We received a packet that is bigger than expected but inside |
852 | * reasonable limits (see previous comment). Just reallocate. |
853 | */ |
854 | if (packet->pages_alloc > p->pages->allocated) { |
855 | multifd_pages_clear(p->pages); |
856 | p->pages = multifd_pages_init(packet->pages_alloc); |
857 | } |
858 | |
859 | p->pages->used = be32_to_cpu(packet->pages_used); |
860 | if (p->pages->used > packet->pages_alloc) { |
861 | error_setg(errp, "multifd: received packet " |
862 | "with %d pages and expected maximum pages are %d" , |
863 | p->pages->used, packet->pages_alloc) ; |
864 | return -1; |
865 | } |
866 | |
867 | p->next_packet_size = be32_to_cpu(packet->next_packet_size); |
868 | p->packet_num = be64_to_cpu(packet->packet_num); |
869 | |
870 | if (p->pages->used) { |
871 | /* make sure that ramblock is 0 terminated */ |
872 | packet->ramblock[255] = 0; |
873 | block = qemu_ram_block_by_name(packet->ramblock); |
874 | if (!block) { |
875 | error_setg(errp, "multifd: unknown ram block %s" , |
876 | packet->ramblock); |
877 | return -1; |
878 | } |
879 | } |
880 | |
881 | for (i = 0; i < p->pages->used; i++) { |
882 | ram_addr_t offset = be64_to_cpu(packet->offset[i]); |
883 | |
884 | if (offset > (block->used_length - TARGET_PAGE_SIZE)) { |
885 | error_setg(errp, "multifd: offset too long " RAM_ADDR_FMT |
886 | " (max " RAM_ADDR_FMT ")" , |
887 | offset, block->max_length); |
888 | return -1; |
889 | } |
890 | p->pages->iov[i].iov_base = block->host + offset; |
891 | p->pages->iov[i].iov_len = TARGET_PAGE_SIZE; |
892 | } |
893 | |
894 | return 0; |
895 | } |
896 | |
897 | struct { |
898 | MultiFDSendParams *params; |
899 | /* array of pages to sent */ |
900 | MultiFDPages_t *pages; |
901 | /* global number of generated multifd packets */ |
902 | uint64_t packet_num; |
903 | /* send channels ready */ |
904 | QemuSemaphore channels_ready; |
905 | } *multifd_send_state; |
906 | |
907 | /* |
908 | * How we use multifd_send_state->pages and channel->pages? |
909 | * |
910 | * We create a pages for each channel, and a main one. Each time that |
911 | * we need to send a batch of pages we interchange the ones between |
912 | * multifd_send_state and the channel that is sending it. There are |
913 | * two reasons for that: |
914 | * - to not have to do so many mallocs during migration |
915 | * - to make easier to know what to free at the end of migration |
916 | * |
917 | * This way we always know who is the owner of each "pages" struct, |
918 | * and we don't need any locking. It belongs to the migration thread |
919 | * or to the channel thread. Switching is safe because the migration |
920 | * thread is using the channel mutex when changing it, and the channel |
921 | * have to had finish with its own, otherwise pending_job can't be |
922 | * false. |
923 | */ |
924 | |
925 | static int multifd_send_pages(RAMState *rs) |
926 | { |
927 | int i; |
928 | static int next_channel; |
929 | MultiFDSendParams *p = NULL; /* make happy gcc */ |
930 | MultiFDPages_t *pages = multifd_send_state->pages; |
931 | uint64_t transferred; |
932 | |
933 | qemu_sem_wait(&multifd_send_state->channels_ready); |
934 | for (i = next_channel;; i = (i + 1) % migrate_multifd_channels()) { |
935 | p = &multifd_send_state->params[i]; |
936 | |
937 | qemu_mutex_lock(&p->mutex); |
938 | if (p->quit) { |
939 | error_report("%s: channel %d has already quit!" , __func__, i); |
940 | qemu_mutex_unlock(&p->mutex); |
941 | return -1; |
942 | } |
943 | if (!p->pending_job) { |
944 | p->pending_job++; |
945 | next_channel = (i + 1) % migrate_multifd_channels(); |
946 | break; |
947 | } |
948 | qemu_mutex_unlock(&p->mutex); |
949 | } |
950 | p->pages->used = 0; |
951 | |
952 | p->packet_num = multifd_send_state->packet_num++; |
953 | p->pages->block = NULL; |
954 | multifd_send_state->pages = p->pages; |
955 | p->pages = pages; |
956 | transferred = ((uint64_t) pages->used) * TARGET_PAGE_SIZE + p->packet_len; |
957 | qemu_file_update_transfer(rs->f, transferred); |
958 | ram_counters.multifd_bytes += transferred; |
959 | ram_counters.transferred += transferred;; |
960 | qemu_mutex_unlock(&p->mutex); |
961 | qemu_sem_post(&p->sem); |
962 | |
963 | return 1; |
964 | } |
965 | |
966 | static int multifd_queue_page(RAMState *rs, RAMBlock *block, ram_addr_t offset) |
967 | { |
968 | MultiFDPages_t *pages = multifd_send_state->pages; |
969 | |
970 | if (!pages->block) { |
971 | pages->block = block; |
972 | } |
973 | |
974 | if (pages->block == block) { |
975 | pages->offset[pages->used] = offset; |
976 | pages->iov[pages->used].iov_base = block->host + offset; |
977 | pages->iov[pages->used].iov_len = TARGET_PAGE_SIZE; |
978 | pages->used++; |
979 | |
980 | if (pages->used < pages->allocated) { |
981 | return 1; |
982 | } |
983 | } |
984 | |
985 | if (multifd_send_pages(rs) < 0) { |
986 | return -1; |
987 | } |
988 | |
989 | if (pages->block != block) { |
990 | return multifd_queue_page(rs, block, offset); |
991 | } |
992 | |
993 | return 1; |
994 | } |
995 | |
996 | static void multifd_send_terminate_threads(Error *err) |
997 | { |
998 | int i; |
999 | |
1000 | trace_multifd_send_terminate_threads(err != NULL); |
1001 | |
1002 | if (err) { |
1003 | MigrationState *s = migrate_get_current(); |
1004 | migrate_set_error(s, err); |
1005 | if (s->state == MIGRATION_STATUS_SETUP || |
1006 | s->state == MIGRATION_STATUS_PRE_SWITCHOVER || |
1007 | s->state == MIGRATION_STATUS_DEVICE || |
1008 | s->state == MIGRATION_STATUS_ACTIVE) { |
1009 | migrate_set_state(&s->state, s->state, |
1010 | MIGRATION_STATUS_FAILED); |
1011 | } |
1012 | } |
1013 | |
1014 | for (i = 0; i < migrate_multifd_channels(); i++) { |
1015 | MultiFDSendParams *p = &multifd_send_state->params[i]; |
1016 | |
1017 | qemu_mutex_lock(&p->mutex); |
1018 | p->quit = true; |
1019 | qemu_sem_post(&p->sem); |
1020 | qemu_mutex_unlock(&p->mutex); |
1021 | } |
1022 | } |
1023 | |
1024 | void multifd_save_cleanup(void) |
1025 | { |
1026 | int i; |
1027 | |
1028 | if (!migrate_use_multifd()) { |
1029 | return; |
1030 | } |
1031 | multifd_send_terminate_threads(NULL); |
1032 | for (i = 0; i < migrate_multifd_channels(); i++) { |
1033 | MultiFDSendParams *p = &multifd_send_state->params[i]; |
1034 | |
1035 | if (p->running) { |
1036 | qemu_thread_join(&p->thread); |
1037 | } |
1038 | socket_send_channel_destroy(p->c); |
1039 | p->c = NULL; |
1040 | qemu_mutex_destroy(&p->mutex); |
1041 | qemu_sem_destroy(&p->sem); |
1042 | qemu_sem_destroy(&p->sem_sync); |
1043 | g_free(p->name); |
1044 | p->name = NULL; |
1045 | multifd_pages_clear(p->pages); |
1046 | p->pages = NULL; |
1047 | p->packet_len = 0; |
1048 | g_free(p->packet); |
1049 | p->packet = NULL; |
1050 | } |
1051 | qemu_sem_destroy(&multifd_send_state->channels_ready); |
1052 | g_free(multifd_send_state->params); |
1053 | multifd_send_state->params = NULL; |
1054 | multifd_pages_clear(multifd_send_state->pages); |
1055 | multifd_send_state->pages = NULL; |
1056 | g_free(multifd_send_state); |
1057 | multifd_send_state = NULL; |
1058 | } |
1059 | |
1060 | static void multifd_send_sync_main(RAMState *rs) |
1061 | { |
1062 | int i; |
1063 | |
1064 | if (!migrate_use_multifd()) { |
1065 | return; |
1066 | } |
1067 | if (multifd_send_state->pages->used) { |
1068 | if (multifd_send_pages(rs) < 0) { |
1069 | error_report("%s: multifd_send_pages fail" , __func__); |
1070 | return; |
1071 | } |
1072 | } |
1073 | for (i = 0; i < migrate_multifd_channels(); i++) { |
1074 | MultiFDSendParams *p = &multifd_send_state->params[i]; |
1075 | |
1076 | trace_multifd_send_sync_main_signal(p->id); |
1077 | |
1078 | qemu_mutex_lock(&p->mutex); |
1079 | |
1080 | if (p->quit) { |
1081 | error_report("%s: channel %d has already quit" , __func__, i); |
1082 | qemu_mutex_unlock(&p->mutex); |
1083 | return; |
1084 | } |
1085 | |
1086 | p->packet_num = multifd_send_state->packet_num++; |
1087 | p->flags |= MULTIFD_FLAG_SYNC; |
1088 | p->pending_job++; |
1089 | qemu_file_update_transfer(rs->f, p->packet_len); |
1090 | ram_counters.multifd_bytes += p->packet_len; |
1091 | ram_counters.transferred += p->packet_len; |
1092 | qemu_mutex_unlock(&p->mutex); |
1093 | qemu_sem_post(&p->sem); |
1094 | } |
1095 | for (i = 0; i < migrate_multifd_channels(); i++) { |
1096 | MultiFDSendParams *p = &multifd_send_state->params[i]; |
1097 | |
1098 | trace_multifd_send_sync_main_wait(p->id); |
1099 | qemu_sem_wait(&p->sem_sync); |
1100 | } |
1101 | trace_multifd_send_sync_main(multifd_send_state->packet_num); |
1102 | } |
1103 | |
1104 | static void *multifd_send_thread(void *opaque) |
1105 | { |
1106 | MultiFDSendParams *p = opaque; |
1107 | Error *local_err = NULL; |
1108 | int ret = 0; |
1109 | uint32_t flags = 0; |
1110 | |
1111 | trace_multifd_send_thread_start(p->id); |
1112 | rcu_register_thread(); |
1113 | |
1114 | if (multifd_send_initial_packet(p, &local_err) < 0) { |
1115 | goto out; |
1116 | } |
1117 | /* initial packet */ |
1118 | p->num_packets = 1; |
1119 | |
1120 | while (true) { |
1121 | qemu_sem_wait(&p->sem); |
1122 | qemu_mutex_lock(&p->mutex); |
1123 | |
1124 | if (p->pending_job) { |
1125 | uint32_t used = p->pages->used; |
1126 | uint64_t packet_num = p->packet_num; |
1127 | flags = p->flags; |
1128 | |
1129 | p->next_packet_size = used * qemu_target_page_size(); |
1130 | multifd_send_fill_packet(p); |
1131 | p->flags = 0; |
1132 | p->num_packets++; |
1133 | p->num_pages += used; |
1134 | p->pages->used = 0; |
1135 | qemu_mutex_unlock(&p->mutex); |
1136 | |
1137 | trace_multifd_send(p->id, packet_num, used, flags, |
1138 | p->next_packet_size); |
1139 | |
1140 | ret = qio_channel_write_all(p->c, (void *)p->packet, |
1141 | p->packet_len, &local_err); |
1142 | if (ret != 0) { |
1143 | break; |
1144 | } |
1145 | |
1146 | if (used) { |
1147 | ret = qio_channel_writev_all(p->c, p->pages->iov, |
1148 | used, &local_err); |
1149 | if (ret != 0) { |
1150 | break; |
1151 | } |
1152 | } |
1153 | |
1154 | qemu_mutex_lock(&p->mutex); |
1155 | p->pending_job--; |
1156 | qemu_mutex_unlock(&p->mutex); |
1157 | |
1158 | if (flags & MULTIFD_FLAG_SYNC) { |
1159 | qemu_sem_post(&p->sem_sync); |
1160 | } |
1161 | qemu_sem_post(&multifd_send_state->channels_ready); |
1162 | } else if (p->quit) { |
1163 | qemu_mutex_unlock(&p->mutex); |
1164 | break; |
1165 | } else { |
1166 | qemu_mutex_unlock(&p->mutex); |
1167 | /* sometimes there are spurious wakeups */ |
1168 | } |
1169 | } |
1170 | |
1171 | out: |
1172 | if (local_err) { |
1173 | trace_multifd_send_error(p->id); |
1174 | multifd_send_terminate_threads(local_err); |
1175 | } |
1176 | |
1177 | /* |
1178 | * Error happen, I will exit, but I can't just leave, tell |
1179 | * who pay attention to me. |
1180 | */ |
1181 | if (ret != 0) { |
1182 | if (flags & MULTIFD_FLAG_SYNC) { |
1183 | qemu_sem_post(&p->sem_sync); |
1184 | } |
1185 | qemu_sem_post(&multifd_send_state->channels_ready); |
1186 | } |
1187 | |
1188 | qemu_mutex_lock(&p->mutex); |
1189 | p->running = false; |
1190 | qemu_mutex_unlock(&p->mutex); |
1191 | |
1192 | rcu_unregister_thread(); |
1193 | trace_multifd_send_thread_end(p->id, p->num_packets, p->num_pages); |
1194 | |
1195 | return NULL; |
1196 | } |
1197 | |
1198 | static void multifd_new_send_channel_async(QIOTask *task, gpointer opaque) |
1199 | { |
1200 | MultiFDSendParams *p = opaque; |
1201 | QIOChannel *sioc = QIO_CHANNEL(qio_task_get_source(task)); |
1202 | Error *local_err = NULL; |
1203 | |
1204 | trace_multifd_new_send_channel_async(p->id); |
1205 | if (qio_task_propagate_error(task, &local_err)) { |
1206 | migrate_set_error(migrate_get_current(), local_err); |
1207 | multifd_save_cleanup(); |
1208 | } else { |
1209 | p->c = QIO_CHANNEL(sioc); |
1210 | qio_channel_set_delay(p->c, false); |
1211 | p->running = true; |
1212 | qemu_thread_create(&p->thread, p->name, multifd_send_thread, p, |
1213 | QEMU_THREAD_JOINABLE); |
1214 | } |
1215 | } |
1216 | |
1217 | int multifd_save_setup(void) |
1218 | { |
1219 | int thread_count; |
1220 | uint32_t page_count = MULTIFD_PACKET_SIZE / qemu_target_page_size(); |
1221 | uint8_t i; |
1222 | |
1223 | if (!migrate_use_multifd()) { |
1224 | return 0; |
1225 | } |
1226 | thread_count = migrate_multifd_channels(); |
1227 | multifd_send_state = g_malloc0(sizeof(*multifd_send_state)); |
1228 | multifd_send_state->params = g_new0(MultiFDSendParams, thread_count); |
1229 | multifd_send_state->pages = multifd_pages_init(page_count); |
1230 | qemu_sem_init(&multifd_send_state->channels_ready, 0); |
1231 | |
1232 | for (i = 0; i < thread_count; i++) { |
1233 | MultiFDSendParams *p = &multifd_send_state->params[i]; |
1234 | |
1235 | qemu_mutex_init(&p->mutex); |
1236 | qemu_sem_init(&p->sem, 0); |
1237 | qemu_sem_init(&p->sem_sync, 0); |
1238 | p->quit = false; |
1239 | p->pending_job = 0; |
1240 | p->id = i; |
1241 | p->pages = multifd_pages_init(page_count); |
1242 | p->packet_len = sizeof(MultiFDPacket_t) |
1243 | + sizeof(ram_addr_t) * page_count; |
1244 | p->packet = g_malloc0(p->packet_len); |
1245 | p->name = g_strdup_printf("multifdsend_%d" , i); |
1246 | socket_send_channel_create(multifd_new_send_channel_async, p); |
1247 | } |
1248 | return 0; |
1249 | } |
1250 | |
1251 | struct { |
1252 | MultiFDRecvParams *params; |
1253 | /* number of created threads */ |
1254 | int count; |
1255 | /* syncs main thread and channels */ |
1256 | QemuSemaphore sem_sync; |
1257 | /* global number of generated multifd packets */ |
1258 | uint64_t packet_num; |
1259 | } *multifd_recv_state; |
1260 | |
1261 | static void multifd_recv_terminate_threads(Error *err) |
1262 | { |
1263 | int i; |
1264 | |
1265 | trace_multifd_recv_terminate_threads(err != NULL); |
1266 | |
1267 | if (err) { |
1268 | MigrationState *s = migrate_get_current(); |
1269 | migrate_set_error(s, err); |
1270 | if (s->state == MIGRATION_STATUS_SETUP || |
1271 | s->state == MIGRATION_STATUS_ACTIVE) { |
1272 | migrate_set_state(&s->state, s->state, |
1273 | MIGRATION_STATUS_FAILED); |
1274 | } |
1275 | } |
1276 | |
1277 | for (i = 0; i < migrate_multifd_channels(); i++) { |
1278 | MultiFDRecvParams *p = &multifd_recv_state->params[i]; |
1279 | |
1280 | qemu_mutex_lock(&p->mutex); |
1281 | p->quit = true; |
1282 | /* We could arrive here for two reasons: |
1283 | - normal quit, i.e. everything went fine, just finished |
1284 | - error quit: We close the channels so the channel threads |
1285 | finish the qio_channel_read_all_eof() */ |
1286 | qio_channel_shutdown(p->c, QIO_CHANNEL_SHUTDOWN_BOTH, NULL); |
1287 | qemu_mutex_unlock(&p->mutex); |
1288 | } |
1289 | } |
1290 | |
1291 | int multifd_load_cleanup(Error **errp) |
1292 | { |
1293 | int i; |
1294 | int ret = 0; |
1295 | |
1296 | if (!migrate_use_multifd()) { |
1297 | return 0; |
1298 | } |
1299 | multifd_recv_terminate_threads(NULL); |
1300 | for (i = 0; i < migrate_multifd_channels(); i++) { |
1301 | MultiFDRecvParams *p = &multifd_recv_state->params[i]; |
1302 | |
1303 | if (p->running) { |
1304 | p->quit = true; |
1305 | /* |
1306 | * multifd_recv_thread may hung at MULTIFD_FLAG_SYNC handle code, |
1307 | * however try to wakeup it without harm in cleanup phase. |
1308 | */ |
1309 | qemu_sem_post(&p->sem_sync); |
1310 | qemu_thread_join(&p->thread); |
1311 | } |
1312 | object_unref(OBJECT(p->c)); |
1313 | p->c = NULL; |
1314 | qemu_mutex_destroy(&p->mutex); |
1315 | qemu_sem_destroy(&p->sem_sync); |
1316 | g_free(p->name); |
1317 | p->name = NULL; |
1318 | multifd_pages_clear(p->pages); |
1319 | p->pages = NULL; |
1320 | p->packet_len = 0; |
1321 | g_free(p->packet); |
1322 | p->packet = NULL; |
1323 | } |
1324 | qemu_sem_destroy(&multifd_recv_state->sem_sync); |
1325 | g_free(multifd_recv_state->params); |
1326 | multifd_recv_state->params = NULL; |
1327 | g_free(multifd_recv_state); |
1328 | multifd_recv_state = NULL; |
1329 | |
1330 | return ret; |
1331 | } |
1332 | |
1333 | static void multifd_recv_sync_main(void) |
1334 | { |
1335 | int i; |
1336 | |
1337 | if (!migrate_use_multifd()) { |
1338 | return; |
1339 | } |
1340 | for (i = 0; i < migrate_multifd_channels(); i++) { |
1341 | MultiFDRecvParams *p = &multifd_recv_state->params[i]; |
1342 | |
1343 | trace_multifd_recv_sync_main_wait(p->id); |
1344 | qemu_sem_wait(&multifd_recv_state->sem_sync); |
1345 | } |
1346 | for (i = 0; i < migrate_multifd_channels(); i++) { |
1347 | MultiFDRecvParams *p = &multifd_recv_state->params[i]; |
1348 | |
1349 | qemu_mutex_lock(&p->mutex); |
1350 | if (multifd_recv_state->packet_num < p->packet_num) { |
1351 | multifd_recv_state->packet_num = p->packet_num; |
1352 | } |
1353 | qemu_mutex_unlock(&p->mutex); |
1354 | trace_multifd_recv_sync_main_signal(p->id); |
1355 | qemu_sem_post(&p->sem_sync); |
1356 | } |
1357 | trace_multifd_recv_sync_main(multifd_recv_state->packet_num); |
1358 | } |
1359 | |
1360 | static void *multifd_recv_thread(void *opaque) |
1361 | { |
1362 | MultiFDRecvParams *p = opaque; |
1363 | Error *local_err = NULL; |
1364 | int ret; |
1365 | |
1366 | trace_multifd_recv_thread_start(p->id); |
1367 | rcu_register_thread(); |
1368 | |
1369 | while (true) { |
1370 | uint32_t used; |
1371 | uint32_t flags; |
1372 | |
1373 | if (p->quit) { |
1374 | break; |
1375 | } |
1376 | |
1377 | ret = qio_channel_read_all_eof(p->c, (void *)p->packet, |
1378 | p->packet_len, &local_err); |
1379 | if (ret == 0) { /* EOF */ |
1380 | break; |
1381 | } |
1382 | if (ret == -1) { /* Error */ |
1383 | break; |
1384 | } |
1385 | |
1386 | qemu_mutex_lock(&p->mutex); |
1387 | ret = multifd_recv_unfill_packet(p, &local_err); |
1388 | if (ret) { |
1389 | qemu_mutex_unlock(&p->mutex); |
1390 | break; |
1391 | } |
1392 | |
1393 | used = p->pages->used; |
1394 | flags = p->flags; |
1395 | trace_multifd_recv(p->id, p->packet_num, used, flags, |
1396 | p->next_packet_size); |
1397 | p->num_packets++; |
1398 | p->num_pages += used; |
1399 | qemu_mutex_unlock(&p->mutex); |
1400 | |
1401 | if (used) { |
1402 | ret = qio_channel_readv_all(p->c, p->pages->iov, |
1403 | used, &local_err); |
1404 | if (ret != 0) { |
1405 | break; |
1406 | } |
1407 | } |
1408 | |
1409 | if (flags & MULTIFD_FLAG_SYNC) { |
1410 | qemu_sem_post(&multifd_recv_state->sem_sync); |
1411 | qemu_sem_wait(&p->sem_sync); |
1412 | } |
1413 | } |
1414 | |
1415 | if (local_err) { |
1416 | multifd_recv_terminate_threads(local_err); |
1417 | } |
1418 | qemu_mutex_lock(&p->mutex); |
1419 | p->running = false; |
1420 | qemu_mutex_unlock(&p->mutex); |
1421 | |
1422 | rcu_unregister_thread(); |
1423 | trace_multifd_recv_thread_end(p->id, p->num_packets, p->num_pages); |
1424 | |
1425 | return NULL; |
1426 | } |
1427 | |
1428 | int multifd_load_setup(void) |
1429 | { |
1430 | int thread_count; |
1431 | uint32_t page_count = MULTIFD_PACKET_SIZE / qemu_target_page_size(); |
1432 | uint8_t i; |
1433 | |
1434 | if (!migrate_use_multifd()) { |
1435 | return 0; |
1436 | } |
1437 | thread_count = migrate_multifd_channels(); |
1438 | multifd_recv_state = g_malloc0(sizeof(*multifd_recv_state)); |
1439 | multifd_recv_state->params = g_new0(MultiFDRecvParams, thread_count); |
1440 | atomic_set(&multifd_recv_state->count, 0); |
1441 | qemu_sem_init(&multifd_recv_state->sem_sync, 0); |
1442 | |
1443 | for (i = 0; i < thread_count; i++) { |
1444 | MultiFDRecvParams *p = &multifd_recv_state->params[i]; |
1445 | |
1446 | qemu_mutex_init(&p->mutex); |
1447 | qemu_sem_init(&p->sem_sync, 0); |
1448 | p->quit = false; |
1449 | p->id = i; |
1450 | p->pages = multifd_pages_init(page_count); |
1451 | p->packet_len = sizeof(MultiFDPacket_t) |
1452 | + sizeof(ram_addr_t) * page_count; |
1453 | p->packet = g_malloc0(p->packet_len); |
1454 | p->name = g_strdup_printf("multifdrecv_%d" , i); |
1455 | } |
1456 | return 0; |
1457 | } |
1458 | |
1459 | bool multifd_recv_all_channels_created(void) |
1460 | { |
1461 | int thread_count = migrate_multifd_channels(); |
1462 | |
1463 | if (!migrate_use_multifd()) { |
1464 | return true; |
1465 | } |
1466 | |
1467 | return thread_count == atomic_read(&multifd_recv_state->count); |
1468 | } |
1469 | |
1470 | /* |
1471 | * Try to receive all multifd channels to get ready for the migration. |
1472 | * - Return true and do not set @errp when correctly receving all channels; |
1473 | * - Return false and do not set @errp when correctly receiving the current one; |
1474 | * - Return false and set @errp when failing to receive the current channel. |
1475 | */ |
1476 | bool multifd_recv_new_channel(QIOChannel *ioc, Error **errp) |
1477 | { |
1478 | MultiFDRecvParams *p; |
1479 | Error *local_err = NULL; |
1480 | int id; |
1481 | |
1482 | id = multifd_recv_initial_packet(ioc, &local_err); |
1483 | if (id < 0) { |
1484 | multifd_recv_terminate_threads(local_err); |
1485 | error_propagate_prepend(errp, local_err, |
1486 | "failed to receive packet" |
1487 | " via multifd channel %d: " , |
1488 | atomic_read(&multifd_recv_state->count)); |
1489 | return false; |
1490 | } |
1491 | trace_multifd_recv_new_channel(id); |
1492 | |
1493 | p = &multifd_recv_state->params[id]; |
1494 | if (p->c != NULL) { |
1495 | error_setg(&local_err, "multifd: received id '%d' already setup'" , |
1496 | id); |
1497 | multifd_recv_terminate_threads(local_err); |
1498 | error_propagate(errp, local_err); |
1499 | return false; |
1500 | } |
1501 | p->c = ioc; |
1502 | object_ref(OBJECT(ioc)); |
1503 | /* initial packet */ |
1504 | p->num_packets = 1; |
1505 | |
1506 | p->running = true; |
1507 | qemu_thread_create(&p->thread, p->name, multifd_recv_thread, p, |
1508 | QEMU_THREAD_JOINABLE); |
1509 | atomic_inc(&multifd_recv_state->count); |
1510 | return atomic_read(&multifd_recv_state->count) == |
1511 | migrate_multifd_channels(); |
1512 | } |
1513 | |
1514 | /** |
1515 | * save_page_header: write page header to wire |
1516 | * |
1517 | * If this is the 1st block, it also writes the block identification |
1518 | * |
1519 | * Returns the number of bytes written |
1520 | * |
1521 | * @f: QEMUFile where to send the data |
1522 | * @block: block that contains the page we want to send |
1523 | * @offset: offset inside the block for the page |
1524 | * in the lower bits, it contains flags |
1525 | */ |
1526 | static size_t (RAMState *rs, QEMUFile *f, RAMBlock *block, |
1527 | ram_addr_t offset) |
1528 | { |
1529 | size_t size, len; |
1530 | |
1531 | if (block == rs->last_sent_block) { |
1532 | offset |= RAM_SAVE_FLAG_CONTINUE; |
1533 | } |
1534 | qemu_put_be64(f, offset); |
1535 | size = 8; |
1536 | |
1537 | if (!(offset & RAM_SAVE_FLAG_CONTINUE)) { |
1538 | len = strlen(block->idstr); |
1539 | qemu_put_byte(f, len); |
1540 | qemu_put_buffer(f, (uint8_t *)block->idstr, len); |
1541 | size += 1 + len; |
1542 | rs->last_sent_block = block; |
1543 | } |
1544 | return size; |
1545 | } |
1546 | |
1547 | /** |
1548 | * mig_throttle_guest_down: throotle down the guest |
1549 | * |
1550 | * Reduce amount of guest cpu execution to hopefully slow down memory |
1551 | * writes. If guest dirty memory rate is reduced below the rate at |
1552 | * which we can transfer pages to the destination then we should be |
1553 | * able to complete migration. Some workloads dirty memory way too |
1554 | * fast and will not effectively converge, even with auto-converge. |
1555 | */ |
1556 | static void mig_throttle_guest_down(void) |
1557 | { |
1558 | MigrationState *s = migrate_get_current(); |
1559 | uint64_t pct_initial = s->parameters.cpu_throttle_initial; |
1560 | uint64_t pct_icrement = s->parameters.cpu_throttle_increment; |
1561 | int pct_max = s->parameters.max_cpu_throttle; |
1562 | |
1563 | /* We have not started throttling yet. Let's start it. */ |
1564 | if (!cpu_throttle_active()) { |
1565 | cpu_throttle_set(pct_initial); |
1566 | } else { |
1567 | /* Throttling already on, just increase the rate */ |
1568 | cpu_throttle_set(MIN(cpu_throttle_get_percentage() + pct_icrement, |
1569 | pct_max)); |
1570 | } |
1571 | } |
1572 | |
1573 | /** |
1574 | * xbzrle_cache_zero_page: insert a zero page in the XBZRLE cache |
1575 | * |
1576 | * @rs: current RAM state |
1577 | * @current_addr: address for the zero page |
1578 | * |
1579 | * Update the xbzrle cache to reflect a page that's been sent as all 0. |
1580 | * The important thing is that a stale (not-yet-0'd) page be replaced |
1581 | * by the new data. |
1582 | * As a bonus, if the page wasn't in the cache it gets added so that |
1583 | * when a small write is made into the 0'd page it gets XBZRLE sent. |
1584 | */ |
1585 | static void xbzrle_cache_zero_page(RAMState *rs, ram_addr_t current_addr) |
1586 | { |
1587 | if (rs->ram_bulk_stage || !migrate_use_xbzrle()) { |
1588 | return; |
1589 | } |
1590 | |
1591 | /* We don't care if this fails to allocate a new cache page |
1592 | * as long as it updated an old one */ |
1593 | cache_insert(XBZRLE.cache, current_addr, XBZRLE.zero_target_page, |
1594 | ram_counters.dirty_sync_count); |
1595 | } |
1596 | |
1597 | #define ENCODING_FLAG_XBZRLE 0x1 |
1598 | |
1599 | /** |
1600 | * save_xbzrle_page: compress and send current page |
1601 | * |
1602 | * Returns: 1 means that we wrote the page |
1603 | * 0 means that page is identical to the one already sent |
1604 | * -1 means that xbzrle would be longer than normal |
1605 | * |
1606 | * @rs: current RAM state |
1607 | * @current_data: pointer to the address of the page contents |
1608 | * @current_addr: addr of the page |
1609 | * @block: block that contains the page we want to send |
1610 | * @offset: offset inside the block for the page |
1611 | * @last_stage: if we are at the completion stage |
1612 | */ |
1613 | static int save_xbzrle_page(RAMState *rs, uint8_t **current_data, |
1614 | ram_addr_t current_addr, RAMBlock *block, |
1615 | ram_addr_t offset, bool last_stage) |
1616 | { |
1617 | int encoded_len = 0, bytes_xbzrle; |
1618 | uint8_t *prev_cached_page; |
1619 | |
1620 | if (!cache_is_cached(XBZRLE.cache, current_addr, |
1621 | ram_counters.dirty_sync_count)) { |
1622 | xbzrle_counters.cache_miss++; |
1623 | if (!last_stage) { |
1624 | if (cache_insert(XBZRLE.cache, current_addr, *current_data, |
1625 | ram_counters.dirty_sync_count) == -1) { |
1626 | return -1; |
1627 | } else { |
1628 | /* update *current_data when the page has been |
1629 | inserted into cache */ |
1630 | *current_data = get_cached_data(XBZRLE.cache, current_addr); |
1631 | } |
1632 | } |
1633 | return -1; |
1634 | } |
1635 | |
1636 | prev_cached_page = get_cached_data(XBZRLE.cache, current_addr); |
1637 | |
1638 | /* save current buffer into memory */ |
1639 | memcpy(XBZRLE.current_buf, *current_data, TARGET_PAGE_SIZE); |
1640 | |
1641 | /* XBZRLE encoding (if there is no overflow) */ |
1642 | encoded_len = xbzrle_encode_buffer(prev_cached_page, XBZRLE.current_buf, |
1643 | TARGET_PAGE_SIZE, XBZRLE.encoded_buf, |
1644 | TARGET_PAGE_SIZE); |
1645 | |
1646 | /* |
1647 | * Update the cache contents, so that it corresponds to the data |
1648 | * sent, in all cases except where we skip the page. |
1649 | */ |
1650 | if (!last_stage && encoded_len != 0) { |
1651 | memcpy(prev_cached_page, XBZRLE.current_buf, TARGET_PAGE_SIZE); |
1652 | /* |
1653 | * In the case where we couldn't compress, ensure that the caller |
1654 | * sends the data from the cache, since the guest might have |
1655 | * changed the RAM since we copied it. |
1656 | */ |
1657 | *current_data = prev_cached_page; |
1658 | } |
1659 | |
1660 | if (encoded_len == 0) { |
1661 | trace_save_xbzrle_page_skipping(); |
1662 | return 0; |
1663 | } else if (encoded_len == -1) { |
1664 | trace_save_xbzrle_page_overflow(); |
1665 | xbzrle_counters.overflow++; |
1666 | return -1; |
1667 | } |
1668 | |
1669 | /* Send XBZRLE based compressed page */ |
1670 | bytes_xbzrle = save_page_header(rs, rs->f, block, |
1671 | offset | RAM_SAVE_FLAG_XBZRLE); |
1672 | qemu_put_byte(rs->f, ENCODING_FLAG_XBZRLE); |
1673 | qemu_put_be16(rs->f, encoded_len); |
1674 | qemu_put_buffer(rs->f, XBZRLE.encoded_buf, encoded_len); |
1675 | bytes_xbzrle += encoded_len + 1 + 2; |
1676 | xbzrle_counters.pages++; |
1677 | xbzrle_counters.bytes += bytes_xbzrle; |
1678 | ram_counters.transferred += bytes_xbzrle; |
1679 | |
1680 | return 1; |
1681 | } |
1682 | |
1683 | /** |
1684 | * migration_bitmap_find_dirty: find the next dirty page from start |
1685 | * |
1686 | * Returns the page offset within memory region of the start of a dirty page |
1687 | * |
1688 | * @rs: current RAM state |
1689 | * @rb: RAMBlock where to search for dirty pages |
1690 | * @start: page where we start the search |
1691 | */ |
1692 | static inline |
1693 | unsigned long migration_bitmap_find_dirty(RAMState *rs, RAMBlock *rb, |
1694 | unsigned long start) |
1695 | { |
1696 | unsigned long size = rb->used_length >> TARGET_PAGE_BITS; |
1697 | unsigned long *bitmap = rb->bmap; |
1698 | unsigned long next; |
1699 | |
1700 | if (ramblock_is_ignored(rb)) { |
1701 | return size; |
1702 | } |
1703 | |
1704 | /* |
1705 | * When the free page optimization is enabled, we need to check the bitmap |
1706 | * to send the non-free pages rather than all the pages in the bulk stage. |
1707 | */ |
1708 | if (!rs->fpo_enabled && rs->ram_bulk_stage && start > 0) { |
1709 | next = start + 1; |
1710 | } else { |
1711 | next = find_next_bit(bitmap, size, start); |
1712 | } |
1713 | |
1714 | return next; |
1715 | } |
1716 | |
1717 | static inline bool migration_bitmap_clear_dirty(RAMState *rs, |
1718 | RAMBlock *rb, |
1719 | unsigned long page) |
1720 | { |
1721 | bool ret; |
1722 | |
1723 | qemu_mutex_lock(&rs->bitmap_mutex); |
1724 | |
1725 | /* |
1726 | * Clear dirty bitmap if needed. This _must_ be called before we |
1727 | * send any of the page in the chunk because we need to make sure |
1728 | * we can capture further page content changes when we sync dirty |
1729 | * log the next time. So as long as we are going to send any of |
1730 | * the page in the chunk we clear the remote dirty bitmap for all. |
1731 | * Clearing it earlier won't be a problem, but too late will. |
1732 | */ |
1733 | if (rb->clear_bmap && clear_bmap_test_and_clear(rb, page)) { |
1734 | uint8_t shift = rb->clear_bmap_shift; |
1735 | hwaddr size = 1ULL << (TARGET_PAGE_BITS + shift); |
1736 | hwaddr start = (page << TARGET_PAGE_BITS) & (-size); |
1737 | |
1738 | /* |
1739 | * CLEAR_BITMAP_SHIFT_MIN should always guarantee this... this |
1740 | * can make things easier sometimes since then start address |
1741 | * of the small chunk will always be 64 pages aligned so the |
1742 | * bitmap will always be aligned to unsigned long. We should |
1743 | * even be able to remove this restriction but I'm simply |
1744 | * keeping it. |
1745 | */ |
1746 | assert(shift >= 6); |
1747 | trace_migration_bitmap_clear_dirty(rb->idstr, start, size, page); |
1748 | memory_region_clear_dirty_bitmap(rb->mr, start, size); |
1749 | } |
1750 | |
1751 | ret = test_and_clear_bit(page, rb->bmap); |
1752 | |
1753 | if (ret) { |
1754 | rs->migration_dirty_pages--; |
1755 | } |
1756 | qemu_mutex_unlock(&rs->bitmap_mutex); |
1757 | |
1758 | return ret; |
1759 | } |
1760 | |
1761 | /* Called with RCU critical section */ |
1762 | static void ramblock_sync_dirty_bitmap(RAMState *rs, RAMBlock *rb) |
1763 | { |
1764 | rs->migration_dirty_pages += |
1765 | cpu_physical_memory_sync_dirty_bitmap(rb, 0, rb->used_length, |
1766 | &rs->num_dirty_pages_period); |
1767 | } |
1768 | |
1769 | /** |
1770 | * ram_pagesize_summary: calculate all the pagesizes of a VM |
1771 | * |
1772 | * Returns a summary bitmap of the page sizes of all RAMBlocks |
1773 | * |
1774 | * For VMs with just normal pages this is equivalent to the host page |
1775 | * size. If it's got some huge pages then it's the OR of all the |
1776 | * different page sizes. |
1777 | */ |
1778 | uint64_t ram_pagesize_summary(void) |
1779 | { |
1780 | RAMBlock *block; |
1781 | uint64_t summary = 0; |
1782 | |
1783 | RAMBLOCK_FOREACH_NOT_IGNORED(block) { |
1784 | summary |= block->page_size; |
1785 | } |
1786 | |
1787 | return summary; |
1788 | } |
1789 | |
1790 | uint64_t ram_get_total_transferred_pages(void) |
1791 | { |
1792 | return ram_counters.normal + ram_counters.duplicate + |
1793 | compression_counters.pages + xbzrle_counters.pages; |
1794 | } |
1795 | |
1796 | static void migration_update_rates(RAMState *rs, int64_t end_time) |
1797 | { |
1798 | uint64_t page_count = rs->target_page_count - rs->target_page_count_prev; |
1799 | double compressed_size; |
1800 | |
1801 | /* calculate period counters */ |
1802 | ram_counters.dirty_pages_rate = rs->num_dirty_pages_period * 1000 |
1803 | / (end_time - rs->time_last_bitmap_sync); |
1804 | |
1805 | if (!page_count) { |
1806 | return; |
1807 | } |
1808 | |
1809 | if (migrate_use_xbzrle()) { |
1810 | xbzrle_counters.cache_miss_rate = (double)(xbzrle_counters.cache_miss - |
1811 | rs->xbzrle_cache_miss_prev) / page_count; |
1812 | rs->xbzrle_cache_miss_prev = xbzrle_counters.cache_miss; |
1813 | } |
1814 | |
1815 | if (migrate_use_compression()) { |
1816 | compression_counters.busy_rate = (double)(compression_counters.busy - |
1817 | rs->compress_thread_busy_prev) / page_count; |
1818 | rs->compress_thread_busy_prev = compression_counters.busy; |
1819 | |
1820 | compressed_size = compression_counters.compressed_size - |
1821 | rs->compressed_size_prev; |
1822 | if (compressed_size) { |
1823 | double uncompressed_size = (compression_counters.pages - |
1824 | rs->compress_pages_prev) * TARGET_PAGE_SIZE; |
1825 | |
1826 | /* Compression-Ratio = Uncompressed-size / Compressed-size */ |
1827 | compression_counters.compression_rate = |
1828 | uncompressed_size / compressed_size; |
1829 | |
1830 | rs->compress_pages_prev = compression_counters.pages; |
1831 | rs->compressed_size_prev = compression_counters.compressed_size; |
1832 | } |
1833 | } |
1834 | } |
1835 | |
1836 | static void migration_bitmap_sync(RAMState *rs) |
1837 | { |
1838 | RAMBlock *block; |
1839 | int64_t end_time; |
1840 | uint64_t bytes_xfer_now; |
1841 | |
1842 | ram_counters.dirty_sync_count++; |
1843 | |
1844 | if (!rs->time_last_bitmap_sync) { |
1845 | rs->time_last_bitmap_sync = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); |
1846 | } |
1847 | |
1848 | trace_migration_bitmap_sync_start(); |
1849 | memory_global_dirty_log_sync(); |
1850 | |
1851 | qemu_mutex_lock(&rs->bitmap_mutex); |
1852 | rcu_read_lock(); |
1853 | RAMBLOCK_FOREACH_NOT_IGNORED(block) { |
1854 | ramblock_sync_dirty_bitmap(rs, block); |
1855 | } |
1856 | ram_counters.remaining = ram_bytes_remaining(); |
1857 | rcu_read_unlock(); |
1858 | qemu_mutex_unlock(&rs->bitmap_mutex); |
1859 | |
1860 | memory_global_after_dirty_log_sync(); |
1861 | trace_migration_bitmap_sync_end(rs->num_dirty_pages_period); |
1862 | |
1863 | end_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); |
1864 | |
1865 | /* more than 1 second = 1000 millisecons */ |
1866 | if (end_time > rs->time_last_bitmap_sync + 1000) { |
1867 | bytes_xfer_now = ram_counters.transferred; |
1868 | |
1869 | /* During block migration the auto-converge logic incorrectly detects |
1870 | * that ram migration makes no progress. Avoid this by disabling the |
1871 | * throttling logic during the bulk phase of block migration. */ |
1872 | if (migrate_auto_converge() && !blk_mig_bulk_active()) { |
1873 | /* The following detection logic can be refined later. For now: |
1874 | Check to see if the dirtied bytes is 50% more than the approx. |
1875 | amount of bytes that just got transferred since the last time we |
1876 | were in this routine. If that happens twice, start or increase |
1877 | throttling */ |
1878 | |
1879 | if ((rs->num_dirty_pages_period * TARGET_PAGE_SIZE > |
1880 | (bytes_xfer_now - rs->bytes_xfer_prev) / 2) && |
1881 | (++rs->dirty_rate_high_cnt >= 2)) { |
1882 | trace_migration_throttle(); |
1883 | rs->dirty_rate_high_cnt = 0; |
1884 | mig_throttle_guest_down(); |
1885 | } |
1886 | } |
1887 | |
1888 | migration_update_rates(rs, end_time); |
1889 | |
1890 | rs->target_page_count_prev = rs->target_page_count; |
1891 | |
1892 | /* reset period counters */ |
1893 | rs->time_last_bitmap_sync = end_time; |
1894 | rs->num_dirty_pages_period = 0; |
1895 | rs->bytes_xfer_prev = bytes_xfer_now; |
1896 | } |
1897 | if (migrate_use_events()) { |
1898 | qapi_event_send_migration_pass(ram_counters.dirty_sync_count); |
1899 | } |
1900 | } |
1901 | |
1902 | static void migration_bitmap_sync_precopy(RAMState *rs) |
1903 | { |
1904 | Error *local_err = NULL; |
1905 | |
1906 | /* |
1907 | * The current notifier usage is just an optimization to migration, so we |
1908 | * don't stop the normal migration process in the error case. |
1909 | */ |
1910 | if (precopy_notify(PRECOPY_NOTIFY_BEFORE_BITMAP_SYNC, &local_err)) { |
1911 | error_report_err(local_err); |
1912 | } |
1913 | |
1914 | migration_bitmap_sync(rs); |
1915 | |
1916 | if (precopy_notify(PRECOPY_NOTIFY_AFTER_BITMAP_SYNC, &local_err)) { |
1917 | error_report_err(local_err); |
1918 | } |
1919 | } |
1920 | |
1921 | /** |
1922 | * save_zero_page_to_file: send the zero page to the file |
1923 | * |
1924 | * Returns the size of data written to the file, 0 means the page is not |
1925 | * a zero page |
1926 | * |
1927 | * @rs: current RAM state |
1928 | * @file: the file where the data is saved |
1929 | * @block: block that contains the page we want to send |
1930 | * @offset: offset inside the block for the page |
1931 | */ |
1932 | static int save_zero_page_to_file(RAMState *rs, QEMUFile *file, |
1933 | RAMBlock *block, ram_addr_t offset) |
1934 | { |
1935 | uint8_t *p = block->host + offset; |
1936 | int len = 0; |
1937 | |
1938 | if (is_zero_range(p, TARGET_PAGE_SIZE)) { |
1939 | len += save_page_header(rs, file, block, offset | RAM_SAVE_FLAG_ZERO); |
1940 | qemu_put_byte(file, 0); |
1941 | len += 1; |
1942 | } |
1943 | return len; |
1944 | } |
1945 | |
1946 | /** |
1947 | * save_zero_page: send the zero page to the stream |
1948 | * |
1949 | * Returns the number of pages written. |
1950 | * |
1951 | * @rs: current RAM state |
1952 | * @block: block that contains the page we want to send |
1953 | * @offset: offset inside the block for the page |
1954 | */ |
1955 | static int save_zero_page(RAMState *rs, RAMBlock *block, ram_addr_t offset) |
1956 | { |
1957 | int len = save_zero_page_to_file(rs, rs->f, block, offset); |
1958 | |
1959 | if (len) { |
1960 | ram_counters.duplicate++; |
1961 | ram_counters.transferred += len; |
1962 | return 1; |
1963 | } |
1964 | return -1; |
1965 | } |
1966 | |
1967 | static void ram_release_pages(const char *rbname, uint64_t offset, int pages) |
1968 | { |
1969 | if (!migrate_release_ram() || !migration_in_postcopy()) { |
1970 | return; |
1971 | } |
1972 | |
1973 | ram_discard_range(rbname, offset, pages << TARGET_PAGE_BITS); |
1974 | } |
1975 | |
1976 | /* |
1977 | * @pages: the number of pages written by the control path, |
1978 | * < 0 - error |
1979 | * > 0 - number of pages written |
1980 | * |
1981 | * Return true if the pages has been saved, otherwise false is returned. |
1982 | */ |
1983 | static bool control_save_page(RAMState *rs, RAMBlock *block, ram_addr_t offset, |
1984 | int *pages) |
1985 | { |
1986 | uint64_t bytes_xmit = 0; |
1987 | int ret; |
1988 | |
1989 | *pages = -1; |
1990 | ret = ram_control_save_page(rs->f, block->offset, offset, TARGET_PAGE_SIZE, |
1991 | &bytes_xmit); |
1992 | if (ret == RAM_SAVE_CONTROL_NOT_SUPP) { |
1993 | return false; |
1994 | } |
1995 | |
1996 | if (bytes_xmit) { |
1997 | ram_counters.transferred += bytes_xmit; |
1998 | *pages = 1; |
1999 | } |
2000 | |
2001 | if (ret == RAM_SAVE_CONTROL_DELAYED) { |
2002 | return true; |
2003 | } |
2004 | |
2005 | if (bytes_xmit > 0) { |
2006 | ram_counters.normal++; |
2007 | } else if (bytes_xmit == 0) { |
2008 | ram_counters.duplicate++; |
2009 | } |
2010 | |
2011 | return true; |
2012 | } |
2013 | |
2014 | /* |
2015 | * directly send the page to the stream |
2016 | * |
2017 | * Returns the number of pages written. |
2018 | * |
2019 | * @rs: current RAM state |
2020 | * @block: block that contains the page we want to send |
2021 | * @offset: offset inside the block for the page |
2022 | * @buf: the page to be sent |
2023 | * @async: send to page asyncly |
2024 | */ |
2025 | static int save_normal_page(RAMState *rs, RAMBlock *block, ram_addr_t offset, |
2026 | uint8_t *buf, bool async) |
2027 | { |
2028 | ram_counters.transferred += save_page_header(rs, rs->f, block, |
2029 | offset | RAM_SAVE_FLAG_PAGE); |
2030 | if (async) { |
2031 | qemu_put_buffer_async(rs->f, buf, TARGET_PAGE_SIZE, |
2032 | migrate_release_ram() & |
2033 | migration_in_postcopy()); |
2034 | } else { |
2035 | qemu_put_buffer(rs->f, buf, TARGET_PAGE_SIZE); |
2036 | } |
2037 | ram_counters.transferred += TARGET_PAGE_SIZE; |
2038 | ram_counters.normal++; |
2039 | return 1; |
2040 | } |
2041 | |
2042 | /** |
2043 | * ram_save_page: send the given page to the stream |
2044 | * |
2045 | * Returns the number of pages written. |
2046 | * < 0 - error |
2047 | * >=0 - Number of pages written - this might legally be 0 |
2048 | * if xbzrle noticed the page was the same. |
2049 | * |
2050 | * @rs: current RAM state |
2051 | * @block: block that contains the page we want to send |
2052 | * @offset: offset inside the block for the page |
2053 | * @last_stage: if we are at the completion stage |
2054 | */ |
2055 | static int ram_save_page(RAMState *rs, PageSearchStatus *pss, bool last_stage) |
2056 | { |
2057 | int pages = -1; |
2058 | uint8_t *p; |
2059 | bool send_async = true; |
2060 | RAMBlock *block = pss->block; |
2061 | ram_addr_t offset = pss->page << TARGET_PAGE_BITS; |
2062 | ram_addr_t current_addr = block->offset + offset; |
2063 | |
2064 | p = block->host + offset; |
2065 | trace_ram_save_page(block->idstr, (uint64_t)offset, p); |
2066 | |
2067 | XBZRLE_cache_lock(); |
2068 | if (!rs->ram_bulk_stage && !migration_in_postcopy() && |
2069 | migrate_use_xbzrle()) { |
2070 | pages = save_xbzrle_page(rs, &p, current_addr, block, |
2071 | offset, last_stage); |
2072 | if (!last_stage) { |
2073 | /* Can't send this cached data async, since the cache page |
2074 | * might get updated before it gets to the wire |
2075 | */ |
2076 | send_async = false; |
2077 | } |
2078 | } |
2079 | |
2080 | /* XBZRLE overflow or normal page */ |
2081 | if (pages == -1) { |
2082 | pages = save_normal_page(rs, block, offset, p, send_async); |
2083 | } |
2084 | |
2085 | XBZRLE_cache_unlock(); |
2086 | |
2087 | return pages; |
2088 | } |
2089 | |
2090 | static int ram_save_multifd_page(RAMState *rs, RAMBlock *block, |
2091 | ram_addr_t offset) |
2092 | { |
2093 | if (multifd_queue_page(rs, block, offset) < 0) { |
2094 | return -1; |
2095 | } |
2096 | ram_counters.normal++; |
2097 | |
2098 | return 1; |
2099 | } |
2100 | |
2101 | static bool do_compress_ram_page(QEMUFile *f, z_stream *stream, RAMBlock *block, |
2102 | ram_addr_t offset, uint8_t *source_buf) |
2103 | { |
2104 | RAMState *rs = ram_state; |
2105 | uint8_t *p = block->host + (offset & TARGET_PAGE_MASK); |
2106 | bool zero_page = false; |
2107 | int ret; |
2108 | |
2109 | if (save_zero_page_to_file(rs, f, block, offset)) { |
2110 | zero_page = true; |
2111 | goto exit; |
2112 | } |
2113 | |
2114 | save_page_header(rs, f, block, offset | RAM_SAVE_FLAG_COMPRESS_PAGE); |
2115 | |
2116 | /* |
2117 | * copy it to a internal buffer to avoid it being modified by VM |
2118 | * so that we can catch up the error during compression and |
2119 | * decompression |
2120 | */ |
2121 | memcpy(source_buf, p, TARGET_PAGE_SIZE); |
2122 | ret = qemu_put_compression_data(f, stream, source_buf, TARGET_PAGE_SIZE); |
2123 | if (ret < 0) { |
2124 | qemu_file_set_error(migrate_get_current()->to_dst_file, ret); |
2125 | error_report("compressed data failed!" ); |
2126 | return false; |
2127 | } |
2128 | |
2129 | exit: |
2130 | ram_release_pages(block->idstr, offset & TARGET_PAGE_MASK, 1); |
2131 | return zero_page; |
2132 | } |
2133 | |
2134 | static void |
2135 | update_compress_thread_counts(const CompressParam *param, int bytes_xmit) |
2136 | { |
2137 | ram_counters.transferred += bytes_xmit; |
2138 | |
2139 | if (param->zero_page) { |
2140 | ram_counters.duplicate++; |
2141 | return; |
2142 | } |
2143 | |
2144 | /* 8 means a header with RAM_SAVE_FLAG_CONTINUE. */ |
2145 | compression_counters.compressed_size += bytes_xmit - 8; |
2146 | compression_counters.pages++; |
2147 | } |
2148 | |
2149 | static bool save_page_use_compression(RAMState *rs); |
2150 | |
2151 | static void flush_compressed_data(RAMState *rs) |
2152 | { |
2153 | int idx, len, thread_count; |
2154 | |
2155 | if (!save_page_use_compression(rs)) { |
2156 | return; |
2157 | } |
2158 | thread_count = migrate_compress_threads(); |
2159 | |
2160 | qemu_mutex_lock(&comp_done_lock); |
2161 | for (idx = 0; idx < thread_count; idx++) { |
2162 | while (!comp_param[idx].done) { |
2163 | qemu_cond_wait(&comp_done_cond, &comp_done_lock); |
2164 | } |
2165 | } |
2166 | qemu_mutex_unlock(&comp_done_lock); |
2167 | |
2168 | for (idx = 0; idx < thread_count; idx++) { |
2169 | qemu_mutex_lock(&comp_param[idx].mutex); |
2170 | if (!comp_param[idx].quit) { |
2171 | len = qemu_put_qemu_file(rs->f, comp_param[idx].file); |
2172 | /* |
2173 | * it's safe to fetch zero_page without holding comp_done_lock |
2174 | * as there is no further request submitted to the thread, |
2175 | * i.e, the thread should be waiting for a request at this point. |
2176 | */ |
2177 | update_compress_thread_counts(&comp_param[idx], len); |
2178 | } |
2179 | qemu_mutex_unlock(&comp_param[idx].mutex); |
2180 | } |
2181 | } |
2182 | |
2183 | static inline void set_compress_params(CompressParam *param, RAMBlock *block, |
2184 | ram_addr_t offset) |
2185 | { |
2186 | param->block = block; |
2187 | param->offset = offset; |
2188 | } |
2189 | |
2190 | static int compress_page_with_multi_thread(RAMState *rs, RAMBlock *block, |
2191 | ram_addr_t offset) |
2192 | { |
2193 | int idx, thread_count, bytes_xmit = -1, pages = -1; |
2194 | bool wait = migrate_compress_wait_thread(); |
2195 | |
2196 | thread_count = migrate_compress_threads(); |
2197 | qemu_mutex_lock(&comp_done_lock); |
2198 | retry: |
2199 | for (idx = 0; idx < thread_count; idx++) { |
2200 | if (comp_param[idx].done) { |
2201 | comp_param[idx].done = false; |
2202 | bytes_xmit = qemu_put_qemu_file(rs->f, comp_param[idx].file); |
2203 | qemu_mutex_lock(&comp_param[idx].mutex); |
2204 | set_compress_params(&comp_param[idx], block, offset); |
2205 | qemu_cond_signal(&comp_param[idx].cond); |
2206 | qemu_mutex_unlock(&comp_param[idx].mutex); |
2207 | pages = 1; |
2208 | update_compress_thread_counts(&comp_param[idx], bytes_xmit); |
2209 | break; |
2210 | } |
2211 | } |
2212 | |
2213 | /* |
2214 | * wait for the free thread if the user specifies 'compress-wait-thread', |
2215 | * otherwise we will post the page out in the main thread as normal page. |
2216 | */ |
2217 | if (pages < 0 && wait) { |
2218 | qemu_cond_wait(&comp_done_cond, &comp_done_lock); |
2219 | goto retry; |
2220 | } |
2221 | qemu_mutex_unlock(&comp_done_lock); |
2222 | |
2223 | return pages; |
2224 | } |
2225 | |
2226 | /** |
2227 | * find_dirty_block: find the next dirty page and update any state |
2228 | * associated with the search process. |
2229 | * |
2230 | * Returns true if a page is found |
2231 | * |
2232 | * @rs: current RAM state |
2233 | * @pss: data about the state of the current dirty page scan |
2234 | * @again: set to false if the search has scanned the whole of RAM |
2235 | */ |
2236 | static bool find_dirty_block(RAMState *rs, PageSearchStatus *pss, bool *again) |
2237 | { |
2238 | pss->page = migration_bitmap_find_dirty(rs, pss->block, pss->page); |
2239 | if (pss->complete_round && pss->block == rs->last_seen_block && |
2240 | pss->page >= rs->last_page) { |
2241 | /* |
2242 | * We've been once around the RAM and haven't found anything. |
2243 | * Give up. |
2244 | */ |
2245 | *again = false; |
2246 | return false; |
2247 | } |
2248 | if ((pss->page << TARGET_PAGE_BITS) >= pss->block->used_length) { |
2249 | /* Didn't find anything in this RAM Block */ |
2250 | pss->page = 0; |
2251 | pss->block = QLIST_NEXT_RCU(pss->block, next); |
2252 | if (!pss->block) { |
2253 | /* |
2254 | * If memory migration starts over, we will meet a dirtied page |
2255 | * which may still exists in compression threads's ring, so we |
2256 | * should flush the compressed data to make sure the new page |
2257 | * is not overwritten by the old one in the destination. |
2258 | * |
2259 | * Also If xbzrle is on, stop using the data compression at this |
2260 | * point. In theory, xbzrle can do better than compression. |
2261 | */ |
2262 | flush_compressed_data(rs); |
2263 | |
2264 | /* Hit the end of the list */ |
2265 | pss->block = QLIST_FIRST_RCU(&ram_list.blocks); |
2266 | /* Flag that we've looped */ |
2267 | pss->complete_round = true; |
2268 | rs->ram_bulk_stage = false; |
2269 | } |
2270 | /* Didn't find anything this time, but try again on the new block */ |
2271 | *again = true; |
2272 | return false; |
2273 | } else { |
2274 | /* Can go around again, but... */ |
2275 | *again = true; |
2276 | /* We've found something so probably don't need to */ |
2277 | return true; |
2278 | } |
2279 | } |
2280 | |
2281 | /** |
2282 | * unqueue_page: gets a page of the queue |
2283 | * |
2284 | * Helper for 'get_queued_page' - gets a page off the queue |
2285 | * |
2286 | * Returns the block of the page (or NULL if none available) |
2287 | * |
2288 | * @rs: current RAM state |
2289 | * @offset: used to return the offset within the RAMBlock |
2290 | */ |
2291 | static RAMBlock *unqueue_page(RAMState *rs, ram_addr_t *offset) |
2292 | { |
2293 | RAMBlock *block = NULL; |
2294 | |
2295 | if (QSIMPLEQ_EMPTY_ATOMIC(&rs->src_page_requests)) { |
2296 | return NULL; |
2297 | } |
2298 | |
2299 | qemu_mutex_lock(&rs->src_page_req_mutex); |
2300 | if (!QSIMPLEQ_EMPTY(&rs->src_page_requests)) { |
2301 | struct RAMSrcPageRequest *entry = |
2302 | QSIMPLEQ_FIRST(&rs->src_page_requests); |
2303 | block = entry->rb; |
2304 | *offset = entry->offset; |
2305 | |
2306 | if (entry->len > TARGET_PAGE_SIZE) { |
2307 | entry->len -= TARGET_PAGE_SIZE; |
2308 | entry->offset += TARGET_PAGE_SIZE; |
2309 | } else { |
2310 | memory_region_unref(block->mr); |
2311 | QSIMPLEQ_REMOVE_HEAD(&rs->src_page_requests, next_req); |
2312 | g_free(entry); |
2313 | migration_consume_urgent_request(); |
2314 | } |
2315 | } |
2316 | qemu_mutex_unlock(&rs->src_page_req_mutex); |
2317 | |
2318 | return block; |
2319 | } |
2320 | |
2321 | /** |
2322 | * get_queued_page: unqueue a page from the postcopy requests |
2323 | * |
2324 | * Skips pages that are already sent (!dirty) |
2325 | * |
2326 | * Returns true if a queued page is found |
2327 | * |
2328 | * @rs: current RAM state |
2329 | * @pss: data about the state of the current dirty page scan |
2330 | */ |
2331 | static bool get_queued_page(RAMState *rs, PageSearchStatus *pss) |
2332 | { |
2333 | RAMBlock *block; |
2334 | ram_addr_t offset; |
2335 | bool dirty; |
2336 | |
2337 | do { |
2338 | block = unqueue_page(rs, &offset); |
2339 | /* |
2340 | * We're sending this page, and since it's postcopy nothing else |
2341 | * will dirty it, and we must make sure it doesn't get sent again |
2342 | * even if this queue request was received after the background |
2343 | * search already sent it. |
2344 | */ |
2345 | if (block) { |
2346 | unsigned long page; |
2347 | |
2348 | page = offset >> TARGET_PAGE_BITS; |
2349 | dirty = test_bit(page, block->bmap); |
2350 | if (!dirty) { |
2351 | trace_get_queued_page_not_dirty(block->idstr, (uint64_t)offset, |
2352 | page, test_bit(page, block->unsentmap)); |
2353 | } else { |
2354 | trace_get_queued_page(block->idstr, (uint64_t)offset, page); |
2355 | } |
2356 | } |
2357 | |
2358 | } while (block && !dirty); |
2359 | |
2360 | if (block) { |
2361 | /* |
2362 | * As soon as we start servicing pages out of order, then we have |
2363 | * to kill the bulk stage, since the bulk stage assumes |
2364 | * in (migration_bitmap_find_and_reset_dirty) that every page is |
2365 | * dirty, that's no longer true. |
2366 | */ |
2367 | rs->ram_bulk_stage = false; |
2368 | |
2369 | /* |
2370 | * We want the background search to continue from the queued page |
2371 | * since the guest is likely to want other pages near to the page |
2372 | * it just requested. |
2373 | */ |
2374 | pss->block = block; |
2375 | pss->page = offset >> TARGET_PAGE_BITS; |
2376 | |
2377 | /* |
2378 | * This unqueued page would break the "one round" check, even is |
2379 | * really rare. |
2380 | */ |
2381 | pss->complete_round = false; |
2382 | } |
2383 | |
2384 | return !!block; |
2385 | } |
2386 | |
2387 | /** |
2388 | * migration_page_queue_free: drop any remaining pages in the ram |
2389 | * request queue |
2390 | * |
2391 | * It should be empty at the end anyway, but in error cases there may |
2392 | * be some left. in case that there is any page left, we drop it. |
2393 | * |
2394 | */ |
2395 | static void migration_page_queue_free(RAMState *rs) |
2396 | { |
2397 | struct RAMSrcPageRequest *mspr, *next_mspr; |
2398 | /* This queue generally should be empty - but in the case of a failed |
2399 | * migration might have some droppings in. |
2400 | */ |
2401 | rcu_read_lock(); |
2402 | QSIMPLEQ_FOREACH_SAFE(mspr, &rs->src_page_requests, next_req, next_mspr) { |
2403 | memory_region_unref(mspr->rb->mr); |
2404 | QSIMPLEQ_REMOVE_HEAD(&rs->src_page_requests, next_req); |
2405 | g_free(mspr); |
2406 | } |
2407 | rcu_read_unlock(); |
2408 | } |
2409 | |
2410 | /** |
2411 | * ram_save_queue_pages: queue the page for transmission |
2412 | * |
2413 | * A request from postcopy destination for example. |
2414 | * |
2415 | * Returns zero on success or negative on error |
2416 | * |
2417 | * @rbname: Name of the RAMBLock of the request. NULL means the |
2418 | * same that last one. |
2419 | * @start: starting address from the start of the RAMBlock |
2420 | * @len: length (in bytes) to send |
2421 | */ |
2422 | int ram_save_queue_pages(const char *rbname, ram_addr_t start, ram_addr_t len) |
2423 | { |
2424 | RAMBlock *ramblock; |
2425 | RAMState *rs = ram_state; |
2426 | |
2427 | ram_counters.postcopy_requests++; |
2428 | rcu_read_lock(); |
2429 | if (!rbname) { |
2430 | /* Reuse last RAMBlock */ |
2431 | ramblock = rs->last_req_rb; |
2432 | |
2433 | if (!ramblock) { |
2434 | /* |
2435 | * Shouldn't happen, we can't reuse the last RAMBlock if |
2436 | * it's the 1st request. |
2437 | */ |
2438 | error_report("ram_save_queue_pages no previous block" ); |
2439 | goto err; |
2440 | } |
2441 | } else { |
2442 | ramblock = qemu_ram_block_by_name(rbname); |
2443 | |
2444 | if (!ramblock) { |
2445 | /* We shouldn't be asked for a non-existent RAMBlock */ |
2446 | error_report("ram_save_queue_pages no block '%s'" , rbname); |
2447 | goto err; |
2448 | } |
2449 | rs->last_req_rb = ramblock; |
2450 | } |
2451 | trace_ram_save_queue_pages(ramblock->idstr, start, len); |
2452 | if (start+len > ramblock->used_length) { |
2453 | error_report("%s request overrun start=" RAM_ADDR_FMT " len=" |
2454 | RAM_ADDR_FMT " blocklen=" RAM_ADDR_FMT, |
2455 | __func__, start, len, ramblock->used_length); |
2456 | goto err; |
2457 | } |
2458 | |
2459 | struct RAMSrcPageRequest *new_entry = |
2460 | g_malloc0(sizeof(struct RAMSrcPageRequest)); |
2461 | new_entry->rb = ramblock; |
2462 | new_entry->offset = start; |
2463 | new_entry->len = len; |
2464 | |
2465 | memory_region_ref(ramblock->mr); |
2466 | qemu_mutex_lock(&rs->src_page_req_mutex); |
2467 | QSIMPLEQ_INSERT_TAIL(&rs->src_page_requests, new_entry, next_req); |
2468 | migration_make_urgent_request(); |
2469 | qemu_mutex_unlock(&rs->src_page_req_mutex); |
2470 | rcu_read_unlock(); |
2471 | |
2472 | return 0; |
2473 | |
2474 | err: |
2475 | rcu_read_unlock(); |
2476 | return -1; |
2477 | } |
2478 | |
2479 | static bool save_page_use_compression(RAMState *rs) |
2480 | { |
2481 | if (!migrate_use_compression()) { |
2482 | return false; |
2483 | } |
2484 | |
2485 | /* |
2486 | * If xbzrle is on, stop using the data compression after first |
2487 | * round of migration even if compression is enabled. In theory, |
2488 | * xbzrle can do better than compression. |
2489 | */ |
2490 | if (rs->ram_bulk_stage || !migrate_use_xbzrle()) { |
2491 | return true; |
2492 | } |
2493 | |
2494 | return false; |
2495 | } |
2496 | |
2497 | /* |
2498 | * try to compress the page before posting it out, return true if the page |
2499 | * has been properly handled by compression, otherwise needs other |
2500 | * paths to handle it |
2501 | */ |
2502 | static bool save_compress_page(RAMState *rs, RAMBlock *block, ram_addr_t offset) |
2503 | { |
2504 | if (!save_page_use_compression(rs)) { |
2505 | return false; |
2506 | } |
2507 | |
2508 | /* |
2509 | * When starting the process of a new block, the first page of |
2510 | * the block should be sent out before other pages in the same |
2511 | * block, and all the pages in last block should have been sent |
2512 | * out, keeping this order is important, because the 'cont' flag |
2513 | * is used to avoid resending the block name. |
2514 | * |
2515 | * We post the fist page as normal page as compression will take |
2516 | * much CPU resource. |
2517 | */ |
2518 | if (block != rs->last_sent_block) { |
2519 | flush_compressed_data(rs); |
2520 | return false; |
2521 | } |
2522 | |
2523 | if (compress_page_with_multi_thread(rs, block, offset) > 0) { |
2524 | return true; |
2525 | } |
2526 | |
2527 | compression_counters.busy++; |
2528 | return false; |
2529 | } |
2530 | |
2531 | /** |
2532 | * ram_save_target_page: save one target page |
2533 | * |
2534 | * Returns the number of pages written |
2535 | * |
2536 | * @rs: current RAM state |
2537 | * @pss: data about the page we want to send |
2538 | * @last_stage: if we are at the completion stage |
2539 | */ |
2540 | static int ram_save_target_page(RAMState *rs, PageSearchStatus *pss, |
2541 | bool last_stage) |
2542 | { |
2543 | RAMBlock *block = pss->block; |
2544 | ram_addr_t offset = pss->page << TARGET_PAGE_BITS; |
2545 | int res; |
2546 | |
2547 | if (control_save_page(rs, block, offset, &res)) { |
2548 | return res; |
2549 | } |
2550 | |
2551 | if (save_compress_page(rs, block, offset)) { |
2552 | return 1; |
2553 | } |
2554 | |
2555 | res = save_zero_page(rs, block, offset); |
2556 | if (res > 0) { |
2557 | /* Must let xbzrle know, otherwise a previous (now 0'd) cached |
2558 | * page would be stale |
2559 | */ |
2560 | if (!save_page_use_compression(rs)) { |
2561 | XBZRLE_cache_lock(); |
2562 | xbzrle_cache_zero_page(rs, block->offset + offset); |
2563 | XBZRLE_cache_unlock(); |
2564 | } |
2565 | ram_release_pages(block->idstr, offset, res); |
2566 | return res; |
2567 | } |
2568 | |
2569 | /* |
2570 | * do not use multifd for compression as the first page in the new |
2571 | * block should be posted out before sending the compressed page |
2572 | */ |
2573 | if (!save_page_use_compression(rs) && migrate_use_multifd()) { |
2574 | return ram_save_multifd_page(rs, block, offset); |
2575 | } |
2576 | |
2577 | return ram_save_page(rs, pss, last_stage); |
2578 | } |
2579 | |
2580 | /** |
2581 | * ram_save_host_page: save a whole host page |
2582 | * |
2583 | * Starting at *offset send pages up to the end of the current host |
2584 | * page. It's valid for the initial offset to point into the middle of |
2585 | * a host page in which case the remainder of the hostpage is sent. |
2586 | * Only dirty target pages are sent. Note that the host page size may |
2587 | * be a huge page for this block. |
2588 | * The saving stops at the boundary of the used_length of the block |
2589 | * if the RAMBlock isn't a multiple of the host page size. |
2590 | * |
2591 | * Returns the number of pages written or negative on error |
2592 | * |
2593 | * @rs: current RAM state |
2594 | * @ms: current migration state |
2595 | * @pss: data about the page we want to send |
2596 | * @last_stage: if we are at the completion stage |
2597 | */ |
2598 | static int ram_save_host_page(RAMState *rs, PageSearchStatus *pss, |
2599 | bool last_stage) |
2600 | { |
2601 | int tmppages, pages = 0; |
2602 | size_t pagesize_bits = |
2603 | qemu_ram_pagesize(pss->block) >> TARGET_PAGE_BITS; |
2604 | |
2605 | if (ramblock_is_ignored(pss->block)) { |
2606 | error_report("block %s should not be migrated !" , pss->block->idstr); |
2607 | return 0; |
2608 | } |
2609 | |
2610 | do { |
2611 | /* Check the pages is dirty and if it is send it */ |
2612 | if (!migration_bitmap_clear_dirty(rs, pss->block, pss->page)) { |
2613 | pss->page++; |
2614 | continue; |
2615 | } |
2616 | |
2617 | tmppages = ram_save_target_page(rs, pss, last_stage); |
2618 | if (tmppages < 0) { |
2619 | return tmppages; |
2620 | } |
2621 | |
2622 | pages += tmppages; |
2623 | if (pss->block->unsentmap) { |
2624 | clear_bit(pss->page, pss->block->unsentmap); |
2625 | } |
2626 | |
2627 | pss->page++; |
2628 | } while ((pss->page & (pagesize_bits - 1)) && |
2629 | offset_in_ramblock(pss->block, pss->page << TARGET_PAGE_BITS)); |
2630 | |
2631 | /* The offset we leave with is the last one we looked at */ |
2632 | pss->page--; |
2633 | return pages; |
2634 | } |
2635 | |
2636 | /** |
2637 | * ram_find_and_save_block: finds a dirty page and sends it to f |
2638 | * |
2639 | * Called within an RCU critical section. |
2640 | * |
2641 | * Returns the number of pages written where zero means no dirty pages, |
2642 | * or negative on error |
2643 | * |
2644 | * @rs: current RAM state |
2645 | * @last_stage: if we are at the completion stage |
2646 | * |
2647 | * On systems where host-page-size > target-page-size it will send all the |
2648 | * pages in a host page that are dirty. |
2649 | */ |
2650 | |
2651 | static int ram_find_and_save_block(RAMState *rs, bool last_stage) |
2652 | { |
2653 | PageSearchStatus pss; |
2654 | int pages = 0; |
2655 | bool again, found; |
2656 | |
2657 | /* No dirty page as there is zero RAM */ |
2658 | if (!ram_bytes_total()) { |
2659 | return pages; |
2660 | } |
2661 | |
2662 | pss.block = rs->last_seen_block; |
2663 | pss.page = rs->last_page; |
2664 | pss.complete_round = false; |
2665 | |
2666 | if (!pss.block) { |
2667 | pss.block = QLIST_FIRST_RCU(&ram_list.blocks); |
2668 | } |
2669 | |
2670 | do { |
2671 | again = true; |
2672 | found = get_queued_page(rs, &pss); |
2673 | |
2674 | if (!found) { |
2675 | /* priority queue empty, so just search for something dirty */ |
2676 | found = find_dirty_block(rs, &pss, &again); |
2677 | } |
2678 | |
2679 | if (found) { |
2680 | pages = ram_save_host_page(rs, &pss, last_stage); |
2681 | } |
2682 | } while (!pages && again); |
2683 | |
2684 | rs->last_seen_block = pss.block; |
2685 | rs->last_page = pss.page; |
2686 | |
2687 | return pages; |
2688 | } |
2689 | |
2690 | void acct_update_position(QEMUFile *f, size_t size, bool zero) |
2691 | { |
2692 | uint64_t pages = size / TARGET_PAGE_SIZE; |
2693 | |
2694 | if (zero) { |
2695 | ram_counters.duplicate += pages; |
2696 | } else { |
2697 | ram_counters.normal += pages; |
2698 | ram_counters.transferred += size; |
2699 | qemu_update_position(f, size); |
2700 | } |
2701 | } |
2702 | |
2703 | static uint64_t ram_bytes_total_common(bool count_ignored) |
2704 | { |
2705 | RAMBlock *block; |
2706 | uint64_t total = 0; |
2707 | |
2708 | rcu_read_lock(); |
2709 | if (count_ignored) { |
2710 | RAMBLOCK_FOREACH_MIGRATABLE(block) { |
2711 | total += block->used_length; |
2712 | } |
2713 | } else { |
2714 | RAMBLOCK_FOREACH_NOT_IGNORED(block) { |
2715 | total += block->used_length; |
2716 | } |
2717 | } |
2718 | rcu_read_unlock(); |
2719 | return total; |
2720 | } |
2721 | |
2722 | uint64_t ram_bytes_total(void) |
2723 | { |
2724 | return ram_bytes_total_common(false); |
2725 | } |
2726 | |
2727 | static void xbzrle_load_setup(void) |
2728 | { |
2729 | XBZRLE.decoded_buf = g_malloc(TARGET_PAGE_SIZE); |
2730 | } |
2731 | |
2732 | static void xbzrle_load_cleanup(void) |
2733 | { |
2734 | g_free(XBZRLE.decoded_buf); |
2735 | XBZRLE.decoded_buf = NULL; |
2736 | } |
2737 | |
2738 | static void ram_state_cleanup(RAMState **rsp) |
2739 | { |
2740 | if (*rsp) { |
2741 | migration_page_queue_free(*rsp); |
2742 | qemu_mutex_destroy(&(*rsp)->bitmap_mutex); |
2743 | qemu_mutex_destroy(&(*rsp)->src_page_req_mutex); |
2744 | g_free(*rsp); |
2745 | *rsp = NULL; |
2746 | } |
2747 | } |
2748 | |
2749 | static void xbzrle_cleanup(void) |
2750 | { |
2751 | XBZRLE_cache_lock(); |
2752 | if (XBZRLE.cache) { |
2753 | cache_fini(XBZRLE.cache); |
2754 | g_free(XBZRLE.encoded_buf); |
2755 | g_free(XBZRLE.current_buf); |
2756 | g_free(XBZRLE.zero_target_page); |
2757 | XBZRLE.cache = NULL; |
2758 | XBZRLE.encoded_buf = NULL; |
2759 | XBZRLE.current_buf = NULL; |
2760 | XBZRLE.zero_target_page = NULL; |
2761 | } |
2762 | XBZRLE_cache_unlock(); |
2763 | } |
2764 | |
2765 | static void ram_save_cleanup(void *opaque) |
2766 | { |
2767 | RAMState **rsp = opaque; |
2768 | RAMBlock *block; |
2769 | |
2770 | /* caller have hold iothread lock or is in a bh, so there is |
2771 | * no writing race against the migration bitmap |
2772 | */ |
2773 | memory_global_dirty_log_stop(); |
2774 | |
2775 | RAMBLOCK_FOREACH_NOT_IGNORED(block) { |
2776 | g_free(block->clear_bmap); |
2777 | block->clear_bmap = NULL; |
2778 | g_free(block->bmap); |
2779 | block->bmap = NULL; |
2780 | g_free(block->unsentmap); |
2781 | block->unsentmap = NULL; |
2782 | } |
2783 | |
2784 | xbzrle_cleanup(); |
2785 | compress_threads_save_cleanup(); |
2786 | ram_state_cleanup(rsp); |
2787 | } |
2788 | |
2789 | static void ram_state_reset(RAMState *rs) |
2790 | { |
2791 | rs->last_seen_block = NULL; |
2792 | rs->last_sent_block = NULL; |
2793 | rs->last_page = 0; |
2794 | rs->last_version = ram_list.version; |
2795 | rs->ram_bulk_stage = true; |
2796 | rs->fpo_enabled = false; |
2797 | } |
2798 | |
2799 | #define MAX_WAIT 50 /* ms, half buffered_file limit */ |
2800 | |
2801 | /* |
2802 | * 'expected' is the value you expect the bitmap mostly to be full |
2803 | * of; it won't bother printing lines that are all this value. |
2804 | * If 'todump' is null the migration bitmap is dumped. |
2805 | */ |
2806 | void ram_debug_dump_bitmap(unsigned long *todump, bool expected, |
2807 | unsigned long pages) |
2808 | { |
2809 | int64_t cur; |
2810 | int64_t linelen = 128; |
2811 | char linebuf[129]; |
2812 | |
2813 | for (cur = 0; cur < pages; cur += linelen) { |
2814 | int64_t curb; |
2815 | bool found = false; |
2816 | /* |
2817 | * Last line; catch the case where the line length |
2818 | * is longer than remaining ram |
2819 | */ |
2820 | if (cur + linelen > pages) { |
2821 | linelen = pages - cur; |
2822 | } |
2823 | for (curb = 0; curb < linelen; curb++) { |
2824 | bool thisbit = test_bit(cur + curb, todump); |
2825 | linebuf[curb] = thisbit ? '1' : '.'; |
2826 | found = found || (thisbit != expected); |
2827 | } |
2828 | if (found) { |
2829 | linebuf[curb] = '\0'; |
2830 | fprintf(stderr, "0x%08" PRIx64 " : %s\n" , cur, linebuf); |
2831 | } |
2832 | } |
2833 | } |
2834 | |
2835 | /* **** functions for postcopy ***** */ |
2836 | |
2837 | void ram_postcopy_migrated_memory_release(MigrationState *ms) |
2838 | { |
2839 | struct RAMBlock *block; |
2840 | |
2841 | RAMBLOCK_FOREACH_NOT_IGNORED(block) { |
2842 | unsigned long *bitmap = block->bmap; |
2843 | unsigned long range = block->used_length >> TARGET_PAGE_BITS; |
2844 | unsigned long run_start = find_next_zero_bit(bitmap, range, 0); |
2845 | |
2846 | while (run_start < range) { |
2847 | unsigned long run_end = find_next_bit(bitmap, range, run_start + 1); |
2848 | ram_discard_range(block->idstr, run_start << TARGET_PAGE_BITS, |
2849 | (run_end - run_start) << TARGET_PAGE_BITS); |
2850 | run_start = find_next_zero_bit(bitmap, range, run_end + 1); |
2851 | } |
2852 | } |
2853 | } |
2854 | |
2855 | /** |
2856 | * postcopy_send_discard_bm_ram: discard a RAMBlock |
2857 | * |
2858 | * Returns zero on success |
2859 | * |
2860 | * Callback from postcopy_each_ram_send_discard for each RAMBlock |
2861 | * Note: At this point the 'unsentmap' is the processed bitmap combined |
2862 | * with the dirtymap; so a '1' means it's either dirty or unsent. |
2863 | * |
2864 | * @ms: current migration state |
2865 | * @block: RAMBlock to discard |
2866 | */ |
2867 | static int postcopy_send_discard_bm_ram(MigrationState *ms, RAMBlock *block) |
2868 | { |
2869 | unsigned long end = block->used_length >> TARGET_PAGE_BITS; |
2870 | unsigned long current; |
2871 | unsigned long *unsentmap = block->unsentmap; |
2872 | |
2873 | for (current = 0; current < end; ) { |
2874 | unsigned long one = find_next_bit(unsentmap, end, current); |
2875 | unsigned long zero, discard_length; |
2876 | |
2877 | if (one >= end) { |
2878 | break; |
2879 | } |
2880 | |
2881 | zero = find_next_zero_bit(unsentmap, end, one + 1); |
2882 | |
2883 | if (zero >= end) { |
2884 | discard_length = end - one; |
2885 | } else { |
2886 | discard_length = zero - one; |
2887 | } |
2888 | postcopy_discard_send_range(ms, one, discard_length); |
2889 | current = one + discard_length; |
2890 | } |
2891 | |
2892 | return 0; |
2893 | } |
2894 | |
2895 | /** |
2896 | * postcopy_each_ram_send_discard: discard all RAMBlocks |
2897 | * |
2898 | * Returns 0 for success or negative for error |
2899 | * |
2900 | * Utility for the outgoing postcopy code. |
2901 | * Calls postcopy_send_discard_bm_ram for each RAMBlock |
2902 | * passing it bitmap indexes and name. |
2903 | * (qemu_ram_foreach_block ends up passing unscaled lengths |
2904 | * which would mean postcopy code would have to deal with target page) |
2905 | * |
2906 | * @ms: current migration state |
2907 | */ |
2908 | static int postcopy_each_ram_send_discard(MigrationState *ms) |
2909 | { |
2910 | struct RAMBlock *block; |
2911 | int ret; |
2912 | |
2913 | RAMBLOCK_FOREACH_NOT_IGNORED(block) { |
2914 | postcopy_discard_send_init(ms, block->idstr); |
2915 | |
2916 | /* |
2917 | * Postcopy sends chunks of bitmap over the wire, but it |
2918 | * just needs indexes at this point, avoids it having |
2919 | * target page specific code. |
2920 | */ |
2921 | ret = postcopy_send_discard_bm_ram(ms, block); |
2922 | postcopy_discard_send_finish(ms); |
2923 | if (ret) { |
2924 | return ret; |
2925 | } |
2926 | } |
2927 | |
2928 | return 0; |
2929 | } |
2930 | |
2931 | /** |
2932 | * postcopy_chunk_hostpages_pass: canocalize bitmap in hostpages |
2933 | * |
2934 | * Helper for postcopy_chunk_hostpages; it's called twice to |
2935 | * canonicalize the two bitmaps, that are similar, but one is |
2936 | * inverted. |
2937 | * |
2938 | * Postcopy requires that all target pages in a hostpage are dirty or |
2939 | * clean, not a mix. This function canonicalizes the bitmaps. |
2940 | * |
2941 | * @ms: current migration state |
2942 | * @unsent_pass: if true we need to canonicalize partially unsent host pages |
2943 | * otherwise we need to canonicalize partially dirty host pages |
2944 | * @block: block that contains the page we want to canonicalize |
2945 | */ |
2946 | static void postcopy_chunk_hostpages_pass(MigrationState *ms, bool unsent_pass, |
2947 | RAMBlock *block) |
2948 | { |
2949 | RAMState *rs = ram_state; |
2950 | unsigned long *bitmap = block->bmap; |
2951 | unsigned long *unsentmap = block->unsentmap; |
2952 | unsigned int host_ratio = block->page_size / TARGET_PAGE_SIZE; |
2953 | unsigned long pages = block->used_length >> TARGET_PAGE_BITS; |
2954 | unsigned long run_start; |
2955 | |
2956 | if (block->page_size == TARGET_PAGE_SIZE) { |
2957 | /* Easy case - TPS==HPS for a non-huge page RAMBlock */ |
2958 | return; |
2959 | } |
2960 | |
2961 | if (unsent_pass) { |
2962 | /* Find a sent page */ |
2963 | run_start = find_next_zero_bit(unsentmap, pages, 0); |
2964 | } else { |
2965 | /* Find a dirty page */ |
2966 | run_start = find_next_bit(bitmap, pages, 0); |
2967 | } |
2968 | |
2969 | while (run_start < pages) { |
2970 | |
2971 | /* |
2972 | * If the start of this run of pages is in the middle of a host |
2973 | * page, then we need to fixup this host page. |
2974 | */ |
2975 | if (QEMU_IS_ALIGNED(run_start, host_ratio)) { |
2976 | /* Find the end of this run */ |
2977 | if (unsent_pass) { |
2978 | run_start = find_next_bit(unsentmap, pages, run_start + 1); |
2979 | } else { |
2980 | run_start = find_next_zero_bit(bitmap, pages, run_start + 1); |
2981 | } |
2982 | /* |
2983 | * If the end isn't at the start of a host page, then the |
2984 | * run doesn't finish at the end of a host page |
2985 | * and we need to discard. |
2986 | */ |
2987 | } |
2988 | |
2989 | if (!QEMU_IS_ALIGNED(run_start, host_ratio)) { |
2990 | unsigned long page; |
2991 | unsigned long fixup_start_addr = QEMU_ALIGN_DOWN(run_start, |
2992 | host_ratio); |
2993 | run_start = QEMU_ALIGN_UP(run_start, host_ratio); |
2994 | |
2995 | /* Tell the destination to discard this page */ |
2996 | if (unsent_pass || !test_bit(fixup_start_addr, unsentmap)) { |
2997 | /* For the unsent_pass we: |
2998 | * discard partially sent pages |
2999 | * For the !unsent_pass (dirty) we: |
3000 | * discard partially dirty pages that were sent |
3001 | * (any partially sent pages were already discarded |
3002 | * by the previous unsent_pass) |
3003 | */ |
3004 | postcopy_discard_send_range(ms, fixup_start_addr, host_ratio); |
3005 | } |
3006 | |
3007 | /* Clean up the bitmap */ |
3008 | for (page = fixup_start_addr; |
3009 | page < fixup_start_addr + host_ratio; page++) { |
3010 | /* All pages in this host page are now not sent */ |
3011 | set_bit(page, unsentmap); |
3012 | |
3013 | /* |
3014 | * Remark them as dirty, updating the count for any pages |
3015 | * that weren't previously dirty. |
3016 | */ |
3017 | rs->migration_dirty_pages += !test_and_set_bit(page, bitmap); |
3018 | } |
3019 | } |
3020 | |
3021 | if (unsent_pass) { |
3022 | /* Find the next sent page for the next iteration */ |
3023 | run_start = find_next_zero_bit(unsentmap, pages, run_start); |
3024 | } else { |
3025 | /* Find the next dirty page for the next iteration */ |
3026 | run_start = find_next_bit(bitmap, pages, run_start); |
3027 | } |
3028 | } |
3029 | } |
3030 | |
3031 | /** |
3032 | * postcopy_chunk_hostpages: discard any partially sent host page |
3033 | * |
3034 | * Utility for the outgoing postcopy code. |
3035 | * |
3036 | * Discard any partially sent host-page size chunks, mark any partially |
3037 | * dirty host-page size chunks as all dirty. In this case the host-page |
3038 | * is the host-page for the particular RAMBlock, i.e. it might be a huge page |
3039 | * |
3040 | * Returns zero on success |
3041 | * |
3042 | * @ms: current migration state |
3043 | * @block: block we want to work with |
3044 | */ |
3045 | static int postcopy_chunk_hostpages(MigrationState *ms, RAMBlock *block) |
3046 | { |
3047 | postcopy_discard_send_init(ms, block->idstr); |
3048 | |
3049 | /* First pass: Discard all partially sent host pages */ |
3050 | postcopy_chunk_hostpages_pass(ms, true, block); |
3051 | /* |
3052 | * Second pass: Ensure that all partially dirty host pages are made |
3053 | * fully dirty. |
3054 | */ |
3055 | postcopy_chunk_hostpages_pass(ms, false, block); |
3056 | |
3057 | postcopy_discard_send_finish(ms); |
3058 | return 0; |
3059 | } |
3060 | |
3061 | /** |
3062 | * ram_postcopy_send_discard_bitmap: transmit the discard bitmap |
3063 | * |
3064 | * Returns zero on success |
3065 | * |
3066 | * Transmit the set of pages to be discarded after precopy to the target |
3067 | * these are pages that: |
3068 | * a) Have been previously transmitted but are now dirty again |
3069 | * b) Pages that have never been transmitted, this ensures that |
3070 | * any pages on the destination that have been mapped by background |
3071 | * tasks get discarded (transparent huge pages is the specific concern) |
3072 | * Hopefully this is pretty sparse |
3073 | * |
3074 | * @ms: current migration state |
3075 | */ |
3076 | int ram_postcopy_send_discard_bitmap(MigrationState *ms) |
3077 | { |
3078 | RAMState *rs = ram_state; |
3079 | RAMBlock *block; |
3080 | int ret; |
3081 | |
3082 | rcu_read_lock(); |
3083 | |
3084 | /* This should be our last sync, the src is now paused */ |
3085 | migration_bitmap_sync(rs); |
3086 | |
3087 | /* Easiest way to make sure we don't resume in the middle of a host-page */ |
3088 | rs->last_seen_block = NULL; |
3089 | rs->last_sent_block = NULL; |
3090 | rs->last_page = 0; |
3091 | |
3092 | RAMBLOCK_FOREACH_NOT_IGNORED(block) { |
3093 | unsigned long pages = block->used_length >> TARGET_PAGE_BITS; |
3094 | unsigned long *bitmap = block->bmap; |
3095 | unsigned long *unsentmap = block->unsentmap; |
3096 | |
3097 | if (!unsentmap) { |
3098 | /* We don't have a safe way to resize the sentmap, so |
3099 | * if the bitmap was resized it will be NULL at this |
3100 | * point. |
3101 | */ |
3102 | error_report("migration ram resized during precopy phase" ); |
3103 | rcu_read_unlock(); |
3104 | return -EINVAL; |
3105 | } |
3106 | /* Deal with TPS != HPS and huge pages */ |
3107 | ret = postcopy_chunk_hostpages(ms, block); |
3108 | if (ret) { |
3109 | rcu_read_unlock(); |
3110 | return ret; |
3111 | } |
3112 | |
3113 | /* |
3114 | * Update the unsentmap to be unsentmap = unsentmap | dirty |
3115 | */ |
3116 | bitmap_or(unsentmap, unsentmap, bitmap, pages); |
3117 | #ifdef DEBUG_POSTCOPY |
3118 | ram_debug_dump_bitmap(unsentmap, true, pages); |
3119 | #endif |
3120 | } |
3121 | trace_ram_postcopy_send_discard_bitmap(); |
3122 | |
3123 | ret = postcopy_each_ram_send_discard(ms); |
3124 | rcu_read_unlock(); |
3125 | |
3126 | return ret; |
3127 | } |
3128 | |
3129 | /** |
3130 | * ram_discard_range: discard dirtied pages at the beginning of postcopy |
3131 | * |
3132 | * Returns zero on success |
3133 | * |
3134 | * @rbname: name of the RAMBlock of the request. NULL means the |
3135 | * same that last one. |
3136 | * @start: RAMBlock starting page |
3137 | * @length: RAMBlock size |
3138 | */ |
3139 | int ram_discard_range(const char *rbname, uint64_t start, size_t length) |
3140 | { |
3141 | int ret = -1; |
3142 | |
3143 | trace_ram_discard_range(rbname, start, length); |
3144 | |
3145 | rcu_read_lock(); |
3146 | RAMBlock *rb = qemu_ram_block_by_name(rbname); |
3147 | |
3148 | if (!rb) { |
3149 | error_report("ram_discard_range: Failed to find block '%s'" , rbname); |
3150 | goto err; |
3151 | } |
3152 | |
3153 | /* |
3154 | * On source VM, we don't need to update the received bitmap since |
3155 | * we don't even have one. |
3156 | */ |
3157 | if (rb->receivedmap) { |
3158 | bitmap_clear(rb->receivedmap, start >> qemu_target_page_bits(), |
3159 | length >> qemu_target_page_bits()); |
3160 | } |
3161 | |
3162 | ret = ram_block_discard_range(rb, start, length); |
3163 | |
3164 | err: |
3165 | rcu_read_unlock(); |
3166 | |
3167 | return ret; |
3168 | } |
3169 | |
3170 | /* |
3171 | * For every allocation, we will try not to crash the VM if the |
3172 | * allocation failed. |
3173 | */ |
3174 | static int xbzrle_init(void) |
3175 | { |
3176 | Error *local_err = NULL; |
3177 | |
3178 | if (!migrate_use_xbzrle()) { |
3179 | return 0; |
3180 | } |
3181 | |
3182 | XBZRLE_cache_lock(); |
3183 | |
3184 | XBZRLE.zero_target_page = g_try_malloc0(TARGET_PAGE_SIZE); |
3185 | if (!XBZRLE.zero_target_page) { |
3186 | error_report("%s: Error allocating zero page" , __func__); |
3187 | goto err_out; |
3188 | } |
3189 | |
3190 | XBZRLE.cache = cache_init(migrate_xbzrle_cache_size(), |
3191 | TARGET_PAGE_SIZE, &local_err); |
3192 | if (!XBZRLE.cache) { |
3193 | error_report_err(local_err); |
3194 | goto free_zero_page; |
3195 | } |
3196 | |
3197 | XBZRLE.encoded_buf = g_try_malloc0(TARGET_PAGE_SIZE); |
3198 | if (!XBZRLE.encoded_buf) { |
3199 | error_report("%s: Error allocating encoded_buf" , __func__); |
3200 | goto free_cache; |
3201 | } |
3202 | |
3203 | XBZRLE.current_buf = g_try_malloc(TARGET_PAGE_SIZE); |
3204 | if (!XBZRLE.current_buf) { |
3205 | error_report("%s: Error allocating current_buf" , __func__); |
3206 | goto free_encoded_buf; |
3207 | } |
3208 | |
3209 | /* We are all good */ |
3210 | XBZRLE_cache_unlock(); |
3211 | return 0; |
3212 | |
3213 | free_encoded_buf: |
3214 | g_free(XBZRLE.encoded_buf); |
3215 | XBZRLE.encoded_buf = NULL; |
3216 | free_cache: |
3217 | cache_fini(XBZRLE.cache); |
3218 | XBZRLE.cache = NULL; |
3219 | free_zero_page: |
3220 | g_free(XBZRLE.zero_target_page); |
3221 | XBZRLE.zero_target_page = NULL; |
3222 | err_out: |
3223 | XBZRLE_cache_unlock(); |
3224 | return -ENOMEM; |
3225 | } |
3226 | |
3227 | static int ram_state_init(RAMState **rsp) |
3228 | { |
3229 | *rsp = g_try_new0(RAMState, 1); |
3230 | |
3231 | if (!*rsp) { |
3232 | error_report("%s: Init ramstate fail" , __func__); |
3233 | return -1; |
3234 | } |
3235 | |
3236 | qemu_mutex_init(&(*rsp)->bitmap_mutex); |
3237 | qemu_mutex_init(&(*rsp)->src_page_req_mutex); |
3238 | QSIMPLEQ_INIT(&(*rsp)->src_page_requests); |
3239 | |
3240 | /* |
3241 | * Count the total number of pages used by ram blocks not including any |
3242 | * gaps due to alignment or unplugs. |
3243 | * This must match with the initial values of dirty bitmap. |
3244 | */ |
3245 | (*rsp)->migration_dirty_pages = ram_bytes_total() >> TARGET_PAGE_BITS; |
3246 | ram_state_reset(*rsp); |
3247 | |
3248 | return 0; |
3249 | } |
3250 | |
3251 | static void ram_list_init_bitmaps(void) |
3252 | { |
3253 | MigrationState *ms = migrate_get_current(); |
3254 | RAMBlock *block; |
3255 | unsigned long pages; |
3256 | uint8_t shift; |
3257 | |
3258 | /* Skip setting bitmap if there is no RAM */ |
3259 | if (ram_bytes_total()) { |
3260 | shift = ms->clear_bitmap_shift; |
3261 | if (shift > CLEAR_BITMAP_SHIFT_MAX) { |
3262 | error_report("clear_bitmap_shift (%u) too big, using " |
3263 | "max value (%u)" , shift, CLEAR_BITMAP_SHIFT_MAX); |
3264 | shift = CLEAR_BITMAP_SHIFT_MAX; |
3265 | } else if (shift < CLEAR_BITMAP_SHIFT_MIN) { |
3266 | error_report("clear_bitmap_shift (%u) too small, using " |
3267 | "min value (%u)" , shift, CLEAR_BITMAP_SHIFT_MIN); |
3268 | shift = CLEAR_BITMAP_SHIFT_MIN; |
3269 | } |
3270 | |
3271 | RAMBLOCK_FOREACH_NOT_IGNORED(block) { |
3272 | pages = block->max_length >> TARGET_PAGE_BITS; |
3273 | /* |
3274 | * The initial dirty bitmap for migration must be set with all |
3275 | * ones to make sure we'll migrate every guest RAM page to |
3276 | * destination. |
3277 | * Here we set RAMBlock.bmap all to 1 because when rebegin a |
3278 | * new migration after a failed migration, ram_list. |
3279 | * dirty_memory[DIRTY_MEMORY_MIGRATION] don't include the whole |
3280 | * guest memory. |
3281 | */ |
3282 | block->bmap = bitmap_new(pages); |
3283 | bitmap_set(block->bmap, 0, pages); |
3284 | block->clear_bmap_shift = shift; |
3285 | block->clear_bmap = bitmap_new(clear_bmap_size(pages, shift)); |
3286 | if (migrate_postcopy_ram()) { |
3287 | block->unsentmap = bitmap_new(pages); |
3288 | bitmap_set(block->unsentmap, 0, pages); |
3289 | } |
3290 | } |
3291 | } |
3292 | } |
3293 | |
3294 | static void ram_init_bitmaps(RAMState *rs) |
3295 | { |
3296 | /* For memory_global_dirty_log_start below. */ |
3297 | qemu_mutex_lock_iothread(); |
3298 | qemu_mutex_lock_ramlist(); |
3299 | rcu_read_lock(); |
3300 | |
3301 | ram_list_init_bitmaps(); |
3302 | memory_global_dirty_log_start(); |
3303 | migration_bitmap_sync_precopy(rs); |
3304 | |
3305 | rcu_read_unlock(); |
3306 | qemu_mutex_unlock_ramlist(); |
3307 | qemu_mutex_unlock_iothread(); |
3308 | } |
3309 | |
3310 | static int ram_init_all(RAMState **rsp) |
3311 | { |
3312 | if (ram_state_init(rsp)) { |
3313 | return -1; |
3314 | } |
3315 | |
3316 | if (xbzrle_init()) { |
3317 | ram_state_cleanup(rsp); |
3318 | return -1; |
3319 | } |
3320 | |
3321 | ram_init_bitmaps(*rsp); |
3322 | |
3323 | return 0; |
3324 | } |
3325 | |
3326 | static void ram_state_resume_prepare(RAMState *rs, QEMUFile *out) |
3327 | { |
3328 | RAMBlock *block; |
3329 | uint64_t pages = 0; |
3330 | |
3331 | /* |
3332 | * Postcopy is not using xbzrle/compression, so no need for that. |
3333 | * Also, since source are already halted, we don't need to care |
3334 | * about dirty page logging as well. |
3335 | */ |
3336 | |
3337 | RAMBLOCK_FOREACH_NOT_IGNORED(block) { |
3338 | pages += bitmap_count_one(block->bmap, |
3339 | block->used_length >> TARGET_PAGE_BITS); |
3340 | } |
3341 | |
3342 | /* This may not be aligned with current bitmaps. Recalculate. */ |
3343 | rs->migration_dirty_pages = pages; |
3344 | |
3345 | rs->last_seen_block = NULL; |
3346 | rs->last_sent_block = NULL; |
3347 | rs->last_page = 0; |
3348 | rs->last_version = ram_list.version; |
3349 | /* |
3350 | * Disable the bulk stage, otherwise we'll resend the whole RAM no |
3351 | * matter what we have sent. |
3352 | */ |
3353 | rs->ram_bulk_stage = false; |
3354 | |
3355 | /* Update RAMState cache of output QEMUFile */ |
3356 | rs->f = out; |
3357 | |
3358 | trace_ram_state_resume_prepare(pages); |
3359 | } |
3360 | |
3361 | /* |
3362 | * This function clears bits of the free pages reported by the caller from the |
3363 | * migration dirty bitmap. @addr is the host address corresponding to the |
3364 | * start of the continuous guest free pages, and @len is the total bytes of |
3365 | * those pages. |
3366 | */ |
3367 | void qemu_guest_free_page_hint(void *addr, size_t len) |
3368 | { |
3369 | RAMBlock *block; |
3370 | ram_addr_t offset; |
3371 | size_t used_len, start, npages; |
3372 | MigrationState *s = migrate_get_current(); |
3373 | |
3374 | /* This function is currently expected to be used during live migration */ |
3375 | if (!migration_is_setup_or_active(s->state)) { |
3376 | return; |
3377 | } |
3378 | |
3379 | for (; len > 0; len -= used_len, addr += used_len) { |
3380 | block = qemu_ram_block_from_host(addr, false, &offset); |
3381 | if (unlikely(!block || offset >= block->used_length)) { |
3382 | /* |
3383 | * The implementation might not support RAMBlock resize during |
3384 | * live migration, but it could happen in theory with future |
3385 | * updates. So we add a check here to capture that case. |
3386 | */ |
3387 | error_report_once("%s unexpected error" , __func__); |
3388 | return; |
3389 | } |
3390 | |
3391 | if (len <= block->used_length - offset) { |
3392 | used_len = len; |
3393 | } else { |
3394 | used_len = block->used_length - offset; |
3395 | } |
3396 | |
3397 | start = offset >> TARGET_PAGE_BITS; |
3398 | npages = used_len >> TARGET_PAGE_BITS; |
3399 | |
3400 | qemu_mutex_lock(&ram_state->bitmap_mutex); |
3401 | ram_state->migration_dirty_pages -= |
3402 | bitmap_count_one_with_offset(block->bmap, start, npages); |
3403 | bitmap_clear(block->bmap, start, npages); |
3404 | qemu_mutex_unlock(&ram_state->bitmap_mutex); |
3405 | } |
3406 | } |
3407 | |
3408 | /* |
3409 | * Each of ram_save_setup, ram_save_iterate and ram_save_complete has |
3410 | * long-running RCU critical section. When rcu-reclaims in the code |
3411 | * start to become numerous it will be necessary to reduce the |
3412 | * granularity of these critical sections. |
3413 | */ |
3414 | |
3415 | /** |
3416 | * ram_save_setup: Setup RAM for migration |
3417 | * |
3418 | * Returns zero to indicate success and negative for error |
3419 | * |
3420 | * @f: QEMUFile where to send the data |
3421 | * @opaque: RAMState pointer |
3422 | */ |
3423 | static int ram_save_setup(QEMUFile *f, void *opaque) |
3424 | { |
3425 | RAMState **rsp = opaque; |
3426 | RAMBlock *block; |
3427 | |
3428 | if (compress_threads_save_setup()) { |
3429 | return -1; |
3430 | } |
3431 | |
3432 | /* migration has already setup the bitmap, reuse it. */ |
3433 | if (!migration_in_colo_state()) { |
3434 | if (ram_init_all(rsp) != 0) { |
3435 | compress_threads_save_cleanup(); |
3436 | return -1; |
3437 | } |
3438 | } |
3439 | (*rsp)->f = f; |
3440 | |
3441 | rcu_read_lock(); |
3442 | |
3443 | qemu_put_be64(f, ram_bytes_total_common(true) | RAM_SAVE_FLAG_MEM_SIZE); |
3444 | |
3445 | RAMBLOCK_FOREACH_MIGRATABLE(block) { |
3446 | qemu_put_byte(f, strlen(block->idstr)); |
3447 | qemu_put_buffer(f, (uint8_t *)block->idstr, strlen(block->idstr)); |
3448 | qemu_put_be64(f, block->used_length); |
3449 | if (migrate_postcopy_ram() && block->page_size != qemu_host_page_size) { |
3450 | qemu_put_be64(f, block->page_size); |
3451 | } |
3452 | if (migrate_ignore_shared()) { |
3453 | qemu_put_be64(f, block->mr->addr); |
3454 | } |
3455 | } |
3456 | |
3457 | rcu_read_unlock(); |
3458 | |
3459 | ram_control_before_iterate(f, RAM_CONTROL_SETUP); |
3460 | ram_control_after_iterate(f, RAM_CONTROL_SETUP); |
3461 | |
3462 | multifd_send_sync_main(*rsp); |
3463 | qemu_put_be64(f, RAM_SAVE_FLAG_EOS); |
3464 | qemu_fflush(f); |
3465 | |
3466 | return 0; |
3467 | } |
3468 | |
3469 | /** |
3470 | * ram_save_iterate: iterative stage for migration |
3471 | * |
3472 | * Returns zero to indicate success and negative for error |
3473 | * |
3474 | * @f: QEMUFile where to send the data |
3475 | * @opaque: RAMState pointer |
3476 | */ |
3477 | static int ram_save_iterate(QEMUFile *f, void *opaque) |
3478 | { |
3479 | RAMState **temp = opaque; |
3480 | RAMState *rs = *temp; |
3481 | int ret; |
3482 | int i; |
3483 | int64_t t0; |
3484 | int done = 0; |
3485 | |
3486 | if (blk_mig_bulk_active()) { |
3487 | /* Avoid transferring ram during bulk phase of block migration as |
3488 | * the bulk phase will usually take a long time and transferring |
3489 | * ram updates during that time is pointless. */ |
3490 | goto out; |
3491 | } |
3492 | |
3493 | rcu_read_lock(); |
3494 | if (ram_list.version != rs->last_version) { |
3495 | ram_state_reset(rs); |
3496 | } |
3497 | |
3498 | /* Read version before ram_list.blocks */ |
3499 | smp_rmb(); |
3500 | |
3501 | ram_control_before_iterate(f, RAM_CONTROL_ROUND); |
3502 | |
3503 | t0 = qemu_clock_get_ns(QEMU_CLOCK_REALTIME); |
3504 | i = 0; |
3505 | while ((ret = qemu_file_rate_limit(f)) == 0 || |
3506 | !QSIMPLEQ_EMPTY(&rs->src_page_requests)) { |
3507 | int pages; |
3508 | |
3509 | if (qemu_file_get_error(f)) { |
3510 | break; |
3511 | } |
3512 | |
3513 | pages = ram_find_and_save_block(rs, false); |
3514 | /* no more pages to sent */ |
3515 | if (pages == 0) { |
3516 | done = 1; |
3517 | break; |
3518 | } |
3519 | |
3520 | if (pages < 0) { |
3521 | qemu_file_set_error(f, pages); |
3522 | break; |
3523 | } |
3524 | |
3525 | rs->target_page_count += pages; |
3526 | |
3527 | /* we want to check in the 1st loop, just in case it was the 1st time |
3528 | and we had to sync the dirty bitmap. |
3529 | qemu_clock_get_ns() is a bit expensive, so we only check each some |
3530 | iterations |
3531 | */ |
3532 | if ((i & 63) == 0) { |
3533 | uint64_t t1 = (qemu_clock_get_ns(QEMU_CLOCK_REALTIME) - t0) / 1000000; |
3534 | if (t1 > MAX_WAIT) { |
3535 | trace_ram_save_iterate_big_wait(t1, i); |
3536 | break; |
3537 | } |
3538 | } |
3539 | i++; |
3540 | } |
3541 | rcu_read_unlock(); |
3542 | |
3543 | /* |
3544 | * Must occur before EOS (or any QEMUFile operation) |
3545 | * because of RDMA protocol. |
3546 | */ |
3547 | ram_control_after_iterate(f, RAM_CONTROL_ROUND); |
3548 | |
3549 | out: |
3550 | multifd_send_sync_main(rs); |
3551 | qemu_put_be64(f, RAM_SAVE_FLAG_EOS); |
3552 | qemu_fflush(f); |
3553 | ram_counters.transferred += 8; |
3554 | |
3555 | ret = qemu_file_get_error(f); |
3556 | if (ret < 0) { |
3557 | return ret; |
3558 | } |
3559 | |
3560 | return done; |
3561 | } |
3562 | |
3563 | /** |
3564 | * ram_save_complete: function called to send the remaining amount of ram |
3565 | * |
3566 | * Returns zero to indicate success or negative on error |
3567 | * |
3568 | * Called with iothread lock |
3569 | * |
3570 | * @f: QEMUFile where to send the data |
3571 | * @opaque: RAMState pointer |
3572 | */ |
3573 | static int ram_save_complete(QEMUFile *f, void *opaque) |
3574 | { |
3575 | RAMState **temp = opaque; |
3576 | RAMState *rs = *temp; |
3577 | int ret = 0; |
3578 | |
3579 | rcu_read_lock(); |
3580 | |
3581 | if (!migration_in_postcopy()) { |
3582 | migration_bitmap_sync_precopy(rs); |
3583 | } |
3584 | |
3585 | ram_control_before_iterate(f, RAM_CONTROL_FINISH); |
3586 | |
3587 | /* try transferring iterative blocks of memory */ |
3588 | |
3589 | /* flush all remaining blocks regardless of rate limiting */ |
3590 | while (true) { |
3591 | int pages; |
3592 | |
3593 | pages = ram_find_and_save_block(rs, !migration_in_colo_state()); |
3594 | /* no more blocks to sent */ |
3595 | if (pages == 0) { |
3596 | break; |
3597 | } |
3598 | if (pages < 0) { |
3599 | ret = pages; |
3600 | break; |
3601 | } |
3602 | } |
3603 | |
3604 | flush_compressed_data(rs); |
3605 | ram_control_after_iterate(f, RAM_CONTROL_FINISH); |
3606 | |
3607 | rcu_read_unlock(); |
3608 | |
3609 | multifd_send_sync_main(rs); |
3610 | qemu_put_be64(f, RAM_SAVE_FLAG_EOS); |
3611 | qemu_fflush(f); |
3612 | |
3613 | return ret; |
3614 | } |
3615 | |
3616 | static void ram_save_pending(QEMUFile *f, void *opaque, uint64_t max_size, |
3617 | uint64_t *res_precopy_only, |
3618 | uint64_t *res_compatible, |
3619 | uint64_t *res_postcopy_only) |
3620 | { |
3621 | RAMState **temp = opaque; |
3622 | RAMState *rs = *temp; |
3623 | uint64_t remaining_size; |
3624 | |
3625 | remaining_size = rs->migration_dirty_pages * TARGET_PAGE_SIZE; |
3626 | |
3627 | if (!migration_in_postcopy() && |
3628 | remaining_size < max_size) { |
3629 | qemu_mutex_lock_iothread(); |
3630 | rcu_read_lock(); |
3631 | migration_bitmap_sync_precopy(rs); |
3632 | rcu_read_unlock(); |
3633 | qemu_mutex_unlock_iothread(); |
3634 | remaining_size = rs->migration_dirty_pages * TARGET_PAGE_SIZE; |
3635 | } |
3636 | |
3637 | if (migrate_postcopy_ram()) { |
3638 | /* We can do postcopy, and all the data is postcopiable */ |
3639 | *res_compatible += remaining_size; |
3640 | } else { |
3641 | *res_precopy_only += remaining_size; |
3642 | } |
3643 | } |
3644 | |
3645 | static int load_xbzrle(QEMUFile *f, ram_addr_t addr, void *host) |
3646 | { |
3647 | unsigned int xh_len; |
3648 | int xh_flags; |
3649 | uint8_t *loaded_data; |
3650 | |
3651 | /* extract RLE header */ |
3652 | xh_flags = qemu_get_byte(f); |
3653 | xh_len = qemu_get_be16(f); |
3654 | |
3655 | if (xh_flags != ENCODING_FLAG_XBZRLE) { |
3656 | error_report("Failed to load XBZRLE page - wrong compression!" ); |
3657 | return -1; |
3658 | } |
3659 | |
3660 | if (xh_len > TARGET_PAGE_SIZE) { |
3661 | error_report("Failed to load XBZRLE page - len overflow!" ); |
3662 | return -1; |
3663 | } |
3664 | loaded_data = XBZRLE.decoded_buf; |
3665 | /* load data and decode */ |
3666 | /* it can change loaded_data to point to an internal buffer */ |
3667 | qemu_get_buffer_in_place(f, &loaded_data, xh_len); |
3668 | |
3669 | /* decode RLE */ |
3670 | if (xbzrle_decode_buffer(loaded_data, xh_len, host, |
3671 | TARGET_PAGE_SIZE) == -1) { |
3672 | error_report("Failed to load XBZRLE page - decode error!" ); |
3673 | return -1; |
3674 | } |
3675 | |
3676 | return 0; |
3677 | } |
3678 | |
3679 | /** |
3680 | * ram_block_from_stream: read a RAMBlock id from the migration stream |
3681 | * |
3682 | * Must be called from within a rcu critical section. |
3683 | * |
3684 | * Returns a pointer from within the RCU-protected ram_list. |
3685 | * |
3686 | * @f: QEMUFile where to read the data from |
3687 | * @flags: Page flags (mostly to see if it's a continuation of previous block) |
3688 | */ |
3689 | static inline RAMBlock *ram_block_from_stream(QEMUFile *f, int flags) |
3690 | { |
3691 | static RAMBlock *block = NULL; |
3692 | char id[256]; |
3693 | uint8_t len; |
3694 | |
3695 | if (flags & RAM_SAVE_FLAG_CONTINUE) { |
3696 | if (!block) { |
3697 | error_report("Ack, bad migration stream!" ); |
3698 | return NULL; |
3699 | } |
3700 | return block; |
3701 | } |
3702 | |
3703 | len = qemu_get_byte(f); |
3704 | qemu_get_buffer(f, (uint8_t *)id, len); |
3705 | id[len] = 0; |
3706 | |
3707 | block = qemu_ram_block_by_name(id); |
3708 | if (!block) { |
3709 | error_report("Can't find block %s" , id); |
3710 | return NULL; |
3711 | } |
3712 | |
3713 | if (ramblock_is_ignored(block)) { |
3714 | error_report("block %s should not be migrated !" , id); |
3715 | return NULL; |
3716 | } |
3717 | |
3718 | return block; |
3719 | } |
3720 | |
3721 | static inline void *host_from_ram_block_offset(RAMBlock *block, |
3722 | ram_addr_t offset) |
3723 | { |
3724 | if (!offset_in_ramblock(block, offset)) { |
3725 | return NULL; |
3726 | } |
3727 | |
3728 | return block->host + offset; |
3729 | } |
3730 | |
3731 | static inline void *colo_cache_from_block_offset(RAMBlock *block, |
3732 | ram_addr_t offset) |
3733 | { |
3734 | if (!offset_in_ramblock(block, offset)) { |
3735 | return NULL; |
3736 | } |
3737 | if (!block->colo_cache) { |
3738 | error_report("%s: colo_cache is NULL in block :%s" , |
3739 | __func__, block->idstr); |
3740 | return NULL; |
3741 | } |
3742 | |
3743 | /* |
3744 | * During colo checkpoint, we need bitmap of these migrated pages. |
3745 | * It help us to decide which pages in ram cache should be flushed |
3746 | * into VM's RAM later. |
3747 | */ |
3748 | if (!test_and_set_bit(offset >> TARGET_PAGE_BITS, block->bmap)) { |
3749 | ram_state->migration_dirty_pages++; |
3750 | } |
3751 | return block->colo_cache + offset; |
3752 | } |
3753 | |
3754 | /** |
3755 | * ram_handle_compressed: handle the zero page case |
3756 | * |
3757 | * If a page (or a whole RDMA chunk) has been |
3758 | * determined to be zero, then zap it. |
3759 | * |
3760 | * @host: host address for the zero page |
3761 | * @ch: what the page is filled from. We only support zero |
3762 | * @size: size of the zero page |
3763 | */ |
3764 | void ram_handle_compressed(void *host, uint8_t ch, uint64_t size) |
3765 | { |
3766 | if (ch != 0 || !is_zero_range(host, size)) { |
3767 | memset(host, ch, size); |
3768 | } |
3769 | } |
3770 | |
3771 | /* return the size after decompression, or negative value on error */ |
3772 | static int |
3773 | qemu_uncompress_data(z_stream *stream, uint8_t *dest, size_t dest_len, |
3774 | const uint8_t *source, size_t source_len) |
3775 | { |
3776 | int err; |
3777 | |
3778 | err = inflateReset(stream); |
3779 | if (err != Z_OK) { |
3780 | return -1; |
3781 | } |
3782 | |
3783 | stream->avail_in = source_len; |
3784 | stream->next_in = (uint8_t *)source; |
3785 | stream->avail_out = dest_len; |
3786 | stream->next_out = dest; |
3787 | |
3788 | err = inflate(stream, Z_NO_FLUSH); |
3789 | if (err != Z_STREAM_END) { |
3790 | return -1; |
3791 | } |
3792 | |
3793 | return stream->total_out; |
3794 | } |
3795 | |
3796 | static void *do_data_decompress(void *opaque) |
3797 | { |
3798 | DecompressParam *param = opaque; |
3799 | unsigned long pagesize; |
3800 | uint8_t *des; |
3801 | int len, ret; |
3802 | |
3803 | qemu_mutex_lock(¶m->mutex); |
3804 | while (!param->quit) { |
3805 | if (param->des) { |
3806 | des = param->des; |
3807 | len = param->len; |
3808 | param->des = 0; |
3809 | qemu_mutex_unlock(¶m->mutex); |
3810 | |
3811 | pagesize = TARGET_PAGE_SIZE; |
3812 | |
3813 | ret = qemu_uncompress_data(¶m->stream, des, pagesize, |
3814 | param->compbuf, len); |
3815 | if (ret < 0 && migrate_get_current()->decompress_error_check) { |
3816 | error_report("decompress data failed" ); |
3817 | qemu_file_set_error(decomp_file, ret); |
3818 | } |
3819 | |
3820 | qemu_mutex_lock(&decomp_done_lock); |
3821 | param->done = true; |
3822 | qemu_cond_signal(&decomp_done_cond); |
3823 | qemu_mutex_unlock(&decomp_done_lock); |
3824 | |
3825 | qemu_mutex_lock(¶m->mutex); |
3826 | } else { |
3827 | qemu_cond_wait(¶m->cond, ¶m->mutex); |
3828 | } |
3829 | } |
3830 | qemu_mutex_unlock(¶m->mutex); |
3831 | |
3832 | return NULL; |
3833 | } |
3834 | |
3835 | static int wait_for_decompress_done(void) |
3836 | { |
3837 | int idx, thread_count; |
3838 | |
3839 | if (!migrate_use_compression()) { |
3840 | return 0; |
3841 | } |
3842 | |
3843 | thread_count = migrate_decompress_threads(); |
3844 | qemu_mutex_lock(&decomp_done_lock); |
3845 | for (idx = 0; idx < thread_count; idx++) { |
3846 | while (!decomp_param[idx].done) { |
3847 | qemu_cond_wait(&decomp_done_cond, &decomp_done_lock); |
3848 | } |
3849 | } |
3850 | qemu_mutex_unlock(&decomp_done_lock); |
3851 | return qemu_file_get_error(decomp_file); |
3852 | } |
3853 | |
3854 | static void compress_threads_load_cleanup(void) |
3855 | { |
3856 | int i, thread_count; |
3857 | |
3858 | if (!migrate_use_compression()) { |
3859 | return; |
3860 | } |
3861 | thread_count = migrate_decompress_threads(); |
3862 | for (i = 0; i < thread_count; i++) { |
3863 | /* |
3864 | * we use it as a indicator which shows if the thread is |
3865 | * properly init'd or not |
3866 | */ |
3867 | if (!decomp_param[i].compbuf) { |
3868 | break; |
3869 | } |
3870 | |
3871 | qemu_mutex_lock(&decomp_param[i].mutex); |
3872 | decomp_param[i].quit = true; |
3873 | qemu_cond_signal(&decomp_param[i].cond); |
3874 | qemu_mutex_unlock(&decomp_param[i].mutex); |
3875 | } |
3876 | for (i = 0; i < thread_count; i++) { |
3877 | if (!decomp_param[i].compbuf) { |
3878 | break; |
3879 | } |
3880 | |
3881 | qemu_thread_join(decompress_threads + i); |
3882 | qemu_mutex_destroy(&decomp_param[i].mutex); |
3883 | qemu_cond_destroy(&decomp_param[i].cond); |
3884 | inflateEnd(&decomp_param[i].stream); |
3885 | g_free(decomp_param[i].compbuf); |
3886 | decomp_param[i].compbuf = NULL; |
3887 | } |
3888 | g_free(decompress_threads); |
3889 | g_free(decomp_param); |
3890 | decompress_threads = NULL; |
3891 | decomp_param = NULL; |
3892 | decomp_file = NULL; |
3893 | } |
3894 | |
3895 | static int compress_threads_load_setup(QEMUFile *f) |
3896 | { |
3897 | int i, thread_count; |
3898 | |
3899 | if (!migrate_use_compression()) { |
3900 | return 0; |
3901 | } |
3902 | |
3903 | thread_count = migrate_decompress_threads(); |
3904 | decompress_threads = g_new0(QemuThread, thread_count); |
3905 | decomp_param = g_new0(DecompressParam, thread_count); |
3906 | qemu_mutex_init(&decomp_done_lock); |
3907 | qemu_cond_init(&decomp_done_cond); |
3908 | decomp_file = f; |
3909 | for (i = 0; i < thread_count; i++) { |
3910 | if (inflateInit(&decomp_param[i].stream) != Z_OK) { |
3911 | goto exit; |
3912 | } |
3913 | |
3914 | decomp_param[i].compbuf = g_malloc0(compressBound(TARGET_PAGE_SIZE)); |
3915 | qemu_mutex_init(&decomp_param[i].mutex); |
3916 | qemu_cond_init(&decomp_param[i].cond); |
3917 | decomp_param[i].done = true; |
3918 | decomp_param[i].quit = false; |
3919 | qemu_thread_create(decompress_threads + i, "decompress" , |
3920 | do_data_decompress, decomp_param + i, |
3921 | QEMU_THREAD_JOINABLE); |
3922 | } |
3923 | return 0; |
3924 | exit: |
3925 | compress_threads_load_cleanup(); |
3926 | return -1; |
3927 | } |
3928 | |
3929 | static void decompress_data_with_multi_threads(QEMUFile *f, |
3930 | void *host, int len) |
3931 | { |
3932 | int idx, thread_count; |
3933 | |
3934 | thread_count = migrate_decompress_threads(); |
3935 | qemu_mutex_lock(&decomp_done_lock); |
3936 | while (true) { |
3937 | for (idx = 0; idx < thread_count; idx++) { |
3938 | if (decomp_param[idx].done) { |
3939 | decomp_param[idx].done = false; |
3940 | qemu_mutex_lock(&decomp_param[idx].mutex); |
3941 | qemu_get_buffer(f, decomp_param[idx].compbuf, len); |
3942 | decomp_param[idx].des = host; |
3943 | decomp_param[idx].len = len; |
3944 | qemu_cond_signal(&decomp_param[idx].cond); |
3945 | qemu_mutex_unlock(&decomp_param[idx].mutex); |
3946 | break; |
3947 | } |
3948 | } |
3949 | if (idx < thread_count) { |
3950 | break; |
3951 | } else { |
3952 | qemu_cond_wait(&decomp_done_cond, &decomp_done_lock); |
3953 | } |
3954 | } |
3955 | qemu_mutex_unlock(&decomp_done_lock); |
3956 | } |
3957 | |
3958 | /* |
3959 | * colo cache: this is for secondary VM, we cache the whole |
3960 | * memory of the secondary VM, it is need to hold the global lock |
3961 | * to call this helper. |
3962 | */ |
3963 | int colo_init_ram_cache(void) |
3964 | { |
3965 | RAMBlock *block; |
3966 | |
3967 | rcu_read_lock(); |
3968 | RAMBLOCK_FOREACH_NOT_IGNORED(block) { |
3969 | block->colo_cache = qemu_anon_ram_alloc(block->used_length, |
3970 | NULL, |
3971 | false); |
3972 | if (!block->colo_cache) { |
3973 | error_report("%s: Can't alloc memory for COLO cache of block %s," |
3974 | "size 0x" RAM_ADDR_FMT, __func__, block->idstr, |
3975 | block->used_length); |
3976 | goto out_locked; |
3977 | } |
3978 | memcpy(block->colo_cache, block->host, block->used_length); |
3979 | } |
3980 | rcu_read_unlock(); |
3981 | /* |
3982 | * Record the dirty pages that sent by PVM, we use this dirty bitmap together |
3983 | * with to decide which page in cache should be flushed into SVM's RAM. Here |
3984 | * we use the same name 'ram_bitmap' as for migration. |
3985 | */ |
3986 | if (ram_bytes_total()) { |
3987 | RAMBlock *block; |
3988 | |
3989 | RAMBLOCK_FOREACH_NOT_IGNORED(block) { |
3990 | unsigned long pages = block->max_length >> TARGET_PAGE_BITS; |
3991 | |
3992 | block->bmap = bitmap_new(pages); |
3993 | bitmap_set(block->bmap, 0, pages); |
3994 | } |
3995 | } |
3996 | ram_state = g_new0(RAMState, 1); |
3997 | ram_state->migration_dirty_pages = 0; |
3998 | qemu_mutex_init(&ram_state->bitmap_mutex); |
3999 | memory_global_dirty_log_start(); |
4000 | |
4001 | return 0; |
4002 | |
4003 | out_locked: |
4004 | |
4005 | RAMBLOCK_FOREACH_NOT_IGNORED(block) { |
4006 | if (block->colo_cache) { |
4007 | qemu_anon_ram_free(block->colo_cache, block->used_length); |
4008 | block->colo_cache = NULL; |
4009 | } |
4010 | } |
4011 | |
4012 | rcu_read_unlock(); |
4013 | return -errno; |
4014 | } |
4015 | |
4016 | /* It is need to hold the global lock to call this helper */ |
4017 | void colo_release_ram_cache(void) |
4018 | { |
4019 | RAMBlock *block; |
4020 | |
4021 | memory_global_dirty_log_stop(); |
4022 | RAMBLOCK_FOREACH_NOT_IGNORED(block) { |
4023 | g_free(block->bmap); |
4024 | block->bmap = NULL; |
4025 | } |
4026 | |
4027 | rcu_read_lock(); |
4028 | |
4029 | RAMBLOCK_FOREACH_NOT_IGNORED(block) { |
4030 | if (block->colo_cache) { |
4031 | qemu_anon_ram_free(block->colo_cache, block->used_length); |
4032 | block->colo_cache = NULL; |
4033 | } |
4034 | } |
4035 | |
4036 | rcu_read_unlock(); |
4037 | qemu_mutex_destroy(&ram_state->bitmap_mutex); |
4038 | g_free(ram_state); |
4039 | ram_state = NULL; |
4040 | } |
4041 | |
4042 | /** |
4043 | * ram_load_setup: Setup RAM for migration incoming side |
4044 | * |
4045 | * Returns zero to indicate success and negative for error |
4046 | * |
4047 | * @f: QEMUFile where to receive the data |
4048 | * @opaque: RAMState pointer |
4049 | */ |
4050 | static int ram_load_setup(QEMUFile *f, void *opaque) |
4051 | { |
4052 | if (compress_threads_load_setup(f)) { |
4053 | return -1; |
4054 | } |
4055 | |
4056 | xbzrle_load_setup(); |
4057 | ramblock_recv_map_init(); |
4058 | |
4059 | return 0; |
4060 | } |
4061 | |
4062 | static int ram_load_cleanup(void *opaque) |
4063 | { |
4064 | RAMBlock *rb; |
4065 | |
4066 | RAMBLOCK_FOREACH_NOT_IGNORED(rb) { |
4067 | if (ramblock_is_pmem(rb)) { |
4068 | pmem_persist(rb->host, rb->used_length); |
4069 | } |
4070 | } |
4071 | |
4072 | xbzrle_load_cleanup(); |
4073 | compress_threads_load_cleanup(); |
4074 | |
4075 | RAMBLOCK_FOREACH_NOT_IGNORED(rb) { |
4076 | g_free(rb->receivedmap); |
4077 | rb->receivedmap = NULL; |
4078 | } |
4079 | |
4080 | return 0; |
4081 | } |
4082 | |
4083 | /** |
4084 | * ram_postcopy_incoming_init: allocate postcopy data structures |
4085 | * |
4086 | * Returns 0 for success and negative if there was one error |
4087 | * |
4088 | * @mis: current migration incoming state |
4089 | * |
4090 | * Allocate data structures etc needed by incoming migration with |
4091 | * postcopy-ram. postcopy-ram's similarly names |
4092 | * postcopy_ram_incoming_init does the work. |
4093 | */ |
4094 | int ram_postcopy_incoming_init(MigrationIncomingState *mis) |
4095 | { |
4096 | return postcopy_ram_incoming_init(mis); |
4097 | } |
4098 | |
4099 | /** |
4100 | * ram_load_postcopy: load a page in postcopy case |
4101 | * |
4102 | * Returns 0 for success or -errno in case of error |
4103 | * |
4104 | * Called in postcopy mode by ram_load(). |
4105 | * rcu_read_lock is taken prior to this being called. |
4106 | * |
4107 | * @f: QEMUFile where to send the data |
4108 | */ |
4109 | static int ram_load_postcopy(QEMUFile *f) |
4110 | { |
4111 | int flags = 0, ret = 0; |
4112 | bool place_needed = false; |
4113 | bool matches_target_page_size = false; |
4114 | MigrationIncomingState *mis = migration_incoming_get_current(); |
4115 | /* Temporary page that is later 'placed' */ |
4116 | void *postcopy_host_page = postcopy_get_tmp_page(mis); |
4117 | void *last_host = NULL; |
4118 | bool all_zero = false; |
4119 | |
4120 | while (!ret && !(flags & RAM_SAVE_FLAG_EOS)) { |
4121 | ram_addr_t addr; |
4122 | void *host = NULL; |
4123 | void *page_buffer = NULL; |
4124 | void *place_source = NULL; |
4125 | RAMBlock *block = NULL; |
4126 | uint8_t ch; |
4127 | |
4128 | addr = qemu_get_be64(f); |
4129 | |
4130 | /* |
4131 | * If qemu file error, we should stop here, and then "addr" |
4132 | * may be invalid |
4133 | */ |
4134 | ret = qemu_file_get_error(f); |
4135 | if (ret) { |
4136 | break; |
4137 | } |
4138 | |
4139 | flags = addr & ~TARGET_PAGE_MASK; |
4140 | addr &= TARGET_PAGE_MASK; |
4141 | |
4142 | trace_ram_load_postcopy_loop((uint64_t)addr, flags); |
4143 | place_needed = false; |
4144 | if (flags & (RAM_SAVE_FLAG_ZERO | RAM_SAVE_FLAG_PAGE)) { |
4145 | block = ram_block_from_stream(f, flags); |
4146 | |
4147 | host = host_from_ram_block_offset(block, addr); |
4148 | if (!host) { |
4149 | error_report("Illegal RAM offset " RAM_ADDR_FMT, addr); |
4150 | ret = -EINVAL; |
4151 | break; |
4152 | } |
4153 | matches_target_page_size = block->page_size == TARGET_PAGE_SIZE; |
4154 | /* |
4155 | * Postcopy requires that we place whole host pages atomically; |
4156 | * these may be huge pages for RAMBlocks that are backed by |
4157 | * hugetlbfs. |
4158 | * To make it atomic, the data is read into a temporary page |
4159 | * that's moved into place later. |
4160 | * The migration protocol uses, possibly smaller, target-pages |
4161 | * however the source ensures it always sends all the components |
4162 | * of a host page in order. |
4163 | */ |
4164 | page_buffer = postcopy_host_page + |
4165 | ((uintptr_t)host & (block->page_size - 1)); |
4166 | /* If all TP are zero then we can optimise the place */ |
4167 | if (!((uintptr_t)host & (block->page_size - 1))) { |
4168 | all_zero = true; |
4169 | } else { |
4170 | /* not the 1st TP within the HP */ |
4171 | if (host != (last_host + TARGET_PAGE_SIZE)) { |
4172 | error_report("Non-sequential target page %p/%p" , |
4173 | host, last_host); |
4174 | ret = -EINVAL; |
4175 | break; |
4176 | } |
4177 | } |
4178 | |
4179 | |
4180 | /* |
4181 | * If it's the last part of a host page then we place the host |
4182 | * page |
4183 | */ |
4184 | place_needed = (((uintptr_t)host + TARGET_PAGE_SIZE) & |
4185 | (block->page_size - 1)) == 0; |
4186 | place_source = postcopy_host_page; |
4187 | } |
4188 | last_host = host; |
4189 | |
4190 | switch (flags & ~RAM_SAVE_FLAG_CONTINUE) { |
4191 | case RAM_SAVE_FLAG_ZERO: |
4192 | ch = qemu_get_byte(f); |
4193 | memset(page_buffer, ch, TARGET_PAGE_SIZE); |
4194 | if (ch) { |
4195 | all_zero = false; |
4196 | } |
4197 | break; |
4198 | |
4199 | case RAM_SAVE_FLAG_PAGE: |
4200 | all_zero = false; |
4201 | if (!matches_target_page_size) { |
4202 | /* For huge pages, we always use temporary buffer */ |
4203 | qemu_get_buffer(f, page_buffer, TARGET_PAGE_SIZE); |
4204 | } else { |
4205 | /* |
4206 | * For small pages that matches target page size, we |
4207 | * avoid the qemu_file copy. Instead we directly use |
4208 | * the buffer of QEMUFile to place the page. Note: we |
4209 | * cannot do any QEMUFile operation before using that |
4210 | * buffer to make sure the buffer is valid when |
4211 | * placing the page. |
4212 | */ |
4213 | qemu_get_buffer_in_place(f, (uint8_t **)&place_source, |
4214 | TARGET_PAGE_SIZE); |
4215 | } |
4216 | break; |
4217 | case RAM_SAVE_FLAG_EOS: |
4218 | /* normal exit */ |
4219 | multifd_recv_sync_main(); |
4220 | break; |
4221 | default: |
4222 | error_report("Unknown combination of migration flags: %#x" |
4223 | " (postcopy mode)" , flags); |
4224 | ret = -EINVAL; |
4225 | break; |
4226 | } |
4227 | |
4228 | /* Detect for any possible file errors */ |
4229 | if (!ret && qemu_file_get_error(f)) { |
4230 | ret = qemu_file_get_error(f); |
4231 | } |
4232 | |
4233 | if (!ret && place_needed) { |
4234 | /* This gets called at the last target page in the host page */ |
4235 | void *place_dest = host + TARGET_PAGE_SIZE - block->page_size; |
4236 | |
4237 | if (all_zero) { |
4238 | ret = postcopy_place_page_zero(mis, place_dest, |
4239 | block); |
4240 | } else { |
4241 | ret = postcopy_place_page(mis, place_dest, |
4242 | place_source, block); |
4243 | } |
4244 | } |
4245 | } |
4246 | |
4247 | return ret; |
4248 | } |
4249 | |
4250 | static bool postcopy_is_advised(void) |
4251 | { |
4252 | PostcopyState ps = postcopy_state_get(); |
4253 | return ps >= POSTCOPY_INCOMING_ADVISE && ps < POSTCOPY_INCOMING_END; |
4254 | } |
4255 | |
4256 | static bool postcopy_is_running(void) |
4257 | { |
4258 | PostcopyState ps = postcopy_state_get(); |
4259 | return ps >= POSTCOPY_INCOMING_LISTENING && ps < POSTCOPY_INCOMING_END; |
4260 | } |
4261 | |
4262 | /* |
4263 | * Flush content of RAM cache into SVM's memory. |
4264 | * Only flush the pages that be dirtied by PVM or SVM or both. |
4265 | */ |
4266 | static void colo_flush_ram_cache(void) |
4267 | { |
4268 | RAMBlock *block = NULL; |
4269 | void *dst_host; |
4270 | void *src_host; |
4271 | unsigned long offset = 0; |
4272 | |
4273 | memory_global_dirty_log_sync(); |
4274 | rcu_read_lock(); |
4275 | RAMBLOCK_FOREACH_NOT_IGNORED(block) { |
4276 | ramblock_sync_dirty_bitmap(ram_state, block); |
4277 | } |
4278 | rcu_read_unlock(); |
4279 | |
4280 | trace_colo_flush_ram_cache_begin(ram_state->migration_dirty_pages); |
4281 | rcu_read_lock(); |
4282 | block = QLIST_FIRST_RCU(&ram_list.blocks); |
4283 | |
4284 | while (block) { |
4285 | offset = migration_bitmap_find_dirty(ram_state, block, offset); |
4286 | |
4287 | if (offset << TARGET_PAGE_BITS >= block->used_length) { |
4288 | offset = 0; |
4289 | block = QLIST_NEXT_RCU(block, next); |
4290 | } else { |
4291 | migration_bitmap_clear_dirty(ram_state, block, offset); |
4292 | dst_host = block->host + (offset << TARGET_PAGE_BITS); |
4293 | src_host = block->colo_cache + (offset << TARGET_PAGE_BITS); |
4294 | memcpy(dst_host, src_host, TARGET_PAGE_SIZE); |
4295 | } |
4296 | } |
4297 | |
4298 | rcu_read_unlock(); |
4299 | trace_colo_flush_ram_cache_end(); |
4300 | } |
4301 | |
4302 | /** |
4303 | * ram_load_precopy: load pages in precopy case |
4304 | * |
4305 | * Returns 0 for success or -errno in case of error |
4306 | * |
4307 | * Called in precopy mode by ram_load(). |
4308 | * rcu_read_lock is taken prior to this being called. |
4309 | * |
4310 | * @f: QEMUFile where to send the data |
4311 | */ |
4312 | static int ram_load_precopy(QEMUFile *f) |
4313 | { |
4314 | int flags = 0, ret = 0, invalid_flags = 0, len = 0; |
4315 | /* ADVISE is earlier, it shows the source has the postcopy capability on */ |
4316 | bool postcopy_advised = postcopy_is_advised(); |
4317 | if (!migrate_use_compression()) { |
4318 | invalid_flags |= RAM_SAVE_FLAG_COMPRESS_PAGE; |
4319 | } |
4320 | |
4321 | while (!ret && !(flags & RAM_SAVE_FLAG_EOS)) { |
4322 | ram_addr_t addr, total_ram_bytes; |
4323 | void *host = NULL; |
4324 | uint8_t ch; |
4325 | |
4326 | addr = qemu_get_be64(f); |
4327 | flags = addr & ~TARGET_PAGE_MASK; |
4328 | addr &= TARGET_PAGE_MASK; |
4329 | |
4330 | if (flags & invalid_flags) { |
4331 | if (flags & invalid_flags & RAM_SAVE_FLAG_COMPRESS_PAGE) { |
4332 | error_report("Received an unexpected compressed page" ); |
4333 | } |
4334 | |
4335 | ret = -EINVAL; |
4336 | break; |
4337 | } |
4338 | |
4339 | if (flags & (RAM_SAVE_FLAG_ZERO | RAM_SAVE_FLAG_PAGE | |
4340 | RAM_SAVE_FLAG_COMPRESS_PAGE | RAM_SAVE_FLAG_XBZRLE)) { |
4341 | RAMBlock *block = ram_block_from_stream(f, flags); |
4342 | |
4343 | /* |
4344 | * After going into COLO, we should load the Page into colo_cache. |
4345 | */ |
4346 | if (migration_incoming_in_colo_state()) { |
4347 | host = colo_cache_from_block_offset(block, addr); |
4348 | } else { |
4349 | host = host_from_ram_block_offset(block, addr); |
4350 | } |
4351 | if (!host) { |
4352 | error_report("Illegal RAM offset " RAM_ADDR_FMT, addr); |
4353 | ret = -EINVAL; |
4354 | break; |
4355 | } |
4356 | |
4357 | if (!migration_incoming_in_colo_state()) { |
4358 | ramblock_recv_bitmap_set(block, host); |
4359 | } |
4360 | |
4361 | trace_ram_load_loop(block->idstr, (uint64_t)addr, flags, host); |
4362 | } |
4363 | |
4364 | switch (flags & ~RAM_SAVE_FLAG_CONTINUE) { |
4365 | case RAM_SAVE_FLAG_MEM_SIZE: |
4366 | /* Synchronize RAM block list */ |
4367 | total_ram_bytes = addr; |
4368 | while (!ret && total_ram_bytes) { |
4369 | RAMBlock *block; |
4370 | char id[256]; |
4371 | ram_addr_t length; |
4372 | |
4373 | len = qemu_get_byte(f); |
4374 | qemu_get_buffer(f, (uint8_t *)id, len); |
4375 | id[len] = 0; |
4376 | length = qemu_get_be64(f); |
4377 | |
4378 | block = qemu_ram_block_by_name(id); |
4379 | if (block && !qemu_ram_is_migratable(block)) { |
4380 | error_report("block %s should not be migrated !" , id); |
4381 | ret = -EINVAL; |
4382 | } else if (block) { |
4383 | if (length != block->used_length) { |
4384 | Error *local_err = NULL; |
4385 | |
4386 | ret = qemu_ram_resize(block, length, |
4387 | &local_err); |
4388 | if (local_err) { |
4389 | error_report_err(local_err); |
4390 | } |
4391 | } |
4392 | /* For postcopy we need to check hugepage sizes match */ |
4393 | if (postcopy_advised && |
4394 | block->page_size != qemu_host_page_size) { |
4395 | uint64_t remote_page_size = qemu_get_be64(f); |
4396 | if (remote_page_size != block->page_size) { |
4397 | error_report("Mismatched RAM page size %s " |
4398 | "(local) %zd != %" PRId64, |
4399 | id, block->page_size, |
4400 | remote_page_size); |
4401 | ret = -EINVAL; |
4402 | } |
4403 | } |
4404 | if (migrate_ignore_shared()) { |
4405 | hwaddr addr = qemu_get_be64(f); |
4406 | if (ramblock_is_ignored(block) && |
4407 | block->mr->addr != addr) { |
4408 | error_report("Mismatched GPAs for block %s " |
4409 | "%" PRId64 "!= %" PRId64, |
4410 | id, (uint64_t)addr, |
4411 | (uint64_t)block->mr->addr); |
4412 | ret = -EINVAL; |
4413 | } |
4414 | } |
4415 | ram_control_load_hook(f, RAM_CONTROL_BLOCK_REG, |
4416 | block->idstr); |
4417 | } else { |
4418 | error_report("Unknown ramblock \"%s\", cannot " |
4419 | "accept migration" , id); |
4420 | ret = -EINVAL; |
4421 | } |
4422 | |
4423 | total_ram_bytes -= length; |
4424 | } |
4425 | break; |
4426 | |
4427 | case RAM_SAVE_FLAG_ZERO: |
4428 | ch = qemu_get_byte(f); |
4429 | ram_handle_compressed(host, ch, TARGET_PAGE_SIZE); |
4430 | break; |
4431 | |
4432 | case RAM_SAVE_FLAG_PAGE: |
4433 | qemu_get_buffer(f, host, TARGET_PAGE_SIZE); |
4434 | break; |
4435 | |
4436 | case RAM_SAVE_FLAG_COMPRESS_PAGE: |
4437 | len = qemu_get_be32(f); |
4438 | if (len < 0 || len > compressBound(TARGET_PAGE_SIZE)) { |
4439 | error_report("Invalid compressed data length: %d" , len); |
4440 | ret = -EINVAL; |
4441 | break; |
4442 | } |
4443 | decompress_data_with_multi_threads(f, host, len); |
4444 | break; |
4445 | |
4446 | case RAM_SAVE_FLAG_XBZRLE: |
4447 | if (load_xbzrle(f, addr, host) < 0) { |
4448 | error_report("Failed to decompress XBZRLE page at " |
4449 | RAM_ADDR_FMT, addr); |
4450 | ret = -EINVAL; |
4451 | break; |
4452 | } |
4453 | break; |
4454 | case RAM_SAVE_FLAG_EOS: |
4455 | /* normal exit */ |
4456 | multifd_recv_sync_main(); |
4457 | break; |
4458 | default: |
4459 | if (flags & RAM_SAVE_FLAG_HOOK) { |
4460 | ram_control_load_hook(f, RAM_CONTROL_HOOK, NULL); |
4461 | } else { |
4462 | error_report("Unknown combination of migration flags: %#x" , |
4463 | flags); |
4464 | ret = -EINVAL; |
4465 | } |
4466 | } |
4467 | if (!ret) { |
4468 | ret = qemu_file_get_error(f); |
4469 | } |
4470 | } |
4471 | |
4472 | return ret; |
4473 | } |
4474 | |
4475 | static int ram_load(QEMUFile *f, void *opaque, int version_id) |
4476 | { |
4477 | int ret = 0; |
4478 | static uint64_t seq_iter; |
4479 | /* |
4480 | * If system is running in postcopy mode, page inserts to host memory must |
4481 | * be atomic |
4482 | */ |
4483 | bool postcopy_running = postcopy_is_running(); |
4484 | |
4485 | seq_iter++; |
4486 | |
4487 | if (version_id != 4) { |
4488 | return -EINVAL; |
4489 | } |
4490 | |
4491 | /* |
4492 | * This RCU critical section can be very long running. |
4493 | * When RCU reclaims in the code start to become numerous, |
4494 | * it will be necessary to reduce the granularity of this |
4495 | * critical section. |
4496 | */ |
4497 | rcu_read_lock(); |
4498 | |
4499 | if (postcopy_running) { |
4500 | ret = ram_load_postcopy(f); |
4501 | } else { |
4502 | ret = ram_load_precopy(f); |
4503 | } |
4504 | |
4505 | ret |= wait_for_decompress_done(); |
4506 | rcu_read_unlock(); |
4507 | trace_ram_load_complete(ret, seq_iter); |
4508 | |
4509 | if (!ret && migration_incoming_in_colo_state()) { |
4510 | colo_flush_ram_cache(); |
4511 | } |
4512 | return ret; |
4513 | } |
4514 | |
4515 | static bool ram_has_postcopy(void *opaque) |
4516 | { |
4517 | RAMBlock *rb; |
4518 | RAMBLOCK_FOREACH_NOT_IGNORED(rb) { |
4519 | if (ramblock_is_pmem(rb)) { |
4520 | info_report("Block: %s, host: %p is a nvdimm memory, postcopy" |
4521 | "is not supported now!" , rb->idstr, rb->host); |
4522 | return false; |
4523 | } |
4524 | } |
4525 | |
4526 | return migrate_postcopy_ram(); |
4527 | } |
4528 | |
4529 | /* Sync all the dirty bitmap with destination VM. */ |
4530 | static int ram_dirty_bitmap_sync_all(MigrationState *s, RAMState *rs) |
4531 | { |
4532 | RAMBlock *block; |
4533 | QEMUFile *file = s->to_dst_file; |
4534 | int ramblock_count = 0; |
4535 | |
4536 | trace_ram_dirty_bitmap_sync_start(); |
4537 | |
4538 | RAMBLOCK_FOREACH_NOT_IGNORED(block) { |
4539 | qemu_savevm_send_recv_bitmap(file, block->idstr); |
4540 | trace_ram_dirty_bitmap_request(block->idstr); |
4541 | ramblock_count++; |
4542 | } |
4543 | |
4544 | trace_ram_dirty_bitmap_sync_wait(); |
4545 | |
4546 | /* Wait until all the ramblocks' dirty bitmap synced */ |
4547 | while (ramblock_count--) { |
4548 | qemu_sem_wait(&s->rp_state.rp_sem); |
4549 | } |
4550 | |
4551 | trace_ram_dirty_bitmap_sync_complete(); |
4552 | |
4553 | return 0; |
4554 | } |
4555 | |
4556 | static void ram_dirty_bitmap_reload_notify(MigrationState *s) |
4557 | { |
4558 | qemu_sem_post(&s->rp_state.rp_sem); |
4559 | } |
4560 | |
4561 | /* |
4562 | * Read the received bitmap, revert it as the initial dirty bitmap. |
4563 | * This is only used when the postcopy migration is paused but wants |
4564 | * to resume from a middle point. |
4565 | */ |
4566 | int ram_dirty_bitmap_reload(MigrationState *s, RAMBlock *block) |
4567 | { |
4568 | int ret = -EINVAL; |
4569 | QEMUFile *file = s->rp_state.from_dst_file; |
4570 | unsigned long *le_bitmap, nbits = block->used_length >> TARGET_PAGE_BITS; |
4571 | uint64_t local_size = DIV_ROUND_UP(nbits, 8); |
4572 | uint64_t size, end_mark; |
4573 | |
4574 | trace_ram_dirty_bitmap_reload_begin(block->idstr); |
4575 | |
4576 | if (s->state != MIGRATION_STATUS_POSTCOPY_RECOVER) { |
4577 | error_report("%s: incorrect state %s" , __func__, |
4578 | MigrationStatus_str(s->state)); |
4579 | return -EINVAL; |
4580 | } |
4581 | |
4582 | /* |
4583 | * Note: see comments in ramblock_recv_bitmap_send() on why we |
4584 | * need the endianess convertion, and the paddings. |
4585 | */ |
4586 | local_size = ROUND_UP(local_size, 8); |
4587 | |
4588 | /* Add paddings */ |
4589 | le_bitmap = bitmap_new(nbits + BITS_PER_LONG); |
4590 | |
4591 | size = qemu_get_be64(file); |
4592 | |
4593 | /* The size of the bitmap should match with our ramblock */ |
4594 | if (size != local_size) { |
4595 | error_report("%s: ramblock '%s' bitmap size mismatch " |
4596 | "(0x%" PRIx64" != 0x%" PRIx64")" , __func__, |
4597 | block->idstr, size, local_size); |
4598 | ret = -EINVAL; |
4599 | goto out; |
4600 | } |
4601 | |
4602 | size = qemu_get_buffer(file, (uint8_t *)le_bitmap, local_size); |
4603 | end_mark = qemu_get_be64(file); |
4604 | |
4605 | ret = qemu_file_get_error(file); |
4606 | if (ret || size != local_size) { |
4607 | error_report("%s: read bitmap failed for ramblock '%s': %d" |
4608 | " (size 0x%" PRIx64", got: 0x%" PRIx64")" , |
4609 | __func__, block->idstr, ret, local_size, size); |
4610 | ret = -EIO; |
4611 | goto out; |
4612 | } |
4613 | |
4614 | if (end_mark != RAMBLOCK_RECV_BITMAP_ENDING) { |
4615 | error_report("%s: ramblock '%s' end mark incorrect: 0x%" PRIu64, |
4616 | __func__, block->idstr, end_mark); |
4617 | ret = -EINVAL; |
4618 | goto out; |
4619 | } |
4620 | |
4621 | /* |
4622 | * Endianess convertion. We are during postcopy (though paused). |
4623 | * The dirty bitmap won't change. We can directly modify it. |
4624 | */ |
4625 | bitmap_from_le(block->bmap, le_bitmap, nbits); |
4626 | |
4627 | /* |
4628 | * What we received is "received bitmap". Revert it as the initial |
4629 | * dirty bitmap for this ramblock. |
4630 | */ |
4631 | bitmap_complement(block->bmap, block->bmap, nbits); |
4632 | |
4633 | trace_ram_dirty_bitmap_reload_complete(block->idstr); |
4634 | |
4635 | /* |
4636 | * We succeeded to sync bitmap for current ramblock. If this is |
4637 | * the last one to sync, we need to notify the main send thread. |
4638 | */ |
4639 | ram_dirty_bitmap_reload_notify(s); |
4640 | |
4641 | ret = 0; |
4642 | out: |
4643 | g_free(le_bitmap); |
4644 | return ret; |
4645 | } |
4646 | |
4647 | static int ram_resume_prepare(MigrationState *s, void *opaque) |
4648 | { |
4649 | RAMState *rs = *(RAMState **)opaque; |
4650 | int ret; |
4651 | |
4652 | ret = ram_dirty_bitmap_sync_all(s, rs); |
4653 | if (ret) { |
4654 | return ret; |
4655 | } |
4656 | |
4657 | ram_state_resume_prepare(rs, s->to_dst_file); |
4658 | |
4659 | return 0; |
4660 | } |
4661 | |
4662 | static SaveVMHandlers savevm_ram_handlers = { |
4663 | .save_setup = ram_save_setup, |
4664 | .save_live_iterate = ram_save_iterate, |
4665 | .save_live_complete_postcopy = ram_save_complete, |
4666 | .save_live_complete_precopy = ram_save_complete, |
4667 | .has_postcopy = ram_has_postcopy, |
4668 | .save_live_pending = ram_save_pending, |
4669 | .load_state = ram_load, |
4670 | .save_cleanup = ram_save_cleanup, |
4671 | .load_setup = ram_load_setup, |
4672 | .load_cleanup = ram_load_cleanup, |
4673 | .resume_prepare = ram_resume_prepare, |
4674 | }; |
4675 | |
4676 | void ram_mig_init(void) |
4677 | { |
4678 | qemu_mutex_init(&XBZRLE.lock); |
4679 | register_savevm_live(NULL, "ram" , 0, 4, &savevm_ram_handlers, &ram_state); |
4680 | } |
4681 | |