1 /* 2 * QEMU live migration 3 * 4 * Copyright IBM, Corp. 2008 5 * 6 * Authors: 7 * Anthony Liguori <aliguori@us.ibm.com> 8 * 9 * This work is licensed under the terms of the GNU GPL, version 2. See 10 * the COPYING file in the top-level directory. 11 * 12 */ 13 14 #ifndef QEMU_MIGRATION_H 15 #define QEMU_MIGRATION_H 16 17 #include "exec/cpu-common.h" 18 #include "hw/qdev-core.h" 19 #include "qapi/qapi-types-migration.h" 20 #include "qemu/thread.h" 21 #include "qemu/coroutine_int.h" 22 #include "io/channel.h" 23 #include "io/channel-buffer.h" 24 #include "net/announce.h" 25 #include "qom/object.h" 26 27 struct PostcopyBlocktimeContext; 28 29 #define MIGRATION_RESUME_ACK_VALUE (1) 30 31 /* 32 * 1<<6=64 pages -> 256K chunk when page size is 4K. This gives us 33 * the benefit that all the chunks are 64 pages aligned then the 34 * bitmaps are always aligned to LONG. 35 */ 36 #define CLEAR_BITMAP_SHIFT_MIN 6 37 /* 38 * 1<<18=256K pages -> 1G chunk when page size is 4K. This is the 39 * default value to use if no one specified. 40 */ 41 #define CLEAR_BITMAP_SHIFT_DEFAULT 18 42 /* 43 * 1<<31=2G pages -> 8T chunk when page size is 4K. This should be 44 * big enough and make sure we won't overflow easily. 45 */ 46 #define CLEAR_BITMAP_SHIFT_MAX 31 47 48 /* State for the incoming migration */ 49 struct MigrationIncomingState { 50 QEMUFile *from_src_file; 51 52 /* 53 * Free at the start of the main state load, set as the main thread finishes 54 * loading state. 55 */ 56 QemuEvent main_thread_load_event; 57 58 /* For network announces */ 59 AnnounceTimer announce_timer; 60 61 size_t largest_page_size; 62 bool have_fault_thread; 63 QemuThread fault_thread; 64 QemuSemaphore fault_thread_sem; 65 /* Set this when we want the fault thread to quit */ 66 bool fault_thread_quit; 67 68 bool have_listen_thread; 69 QemuThread listen_thread; 70 QemuSemaphore listen_thread_sem; 71 72 /* For the kernel to send us notifications */ 73 int userfault_fd; 74 /* To notify the fault_thread to wake, e.g., when need to quit */ 75 int userfault_event_fd; 76 QEMUFile *to_src_file; 77 QemuMutex rp_mutex; /* We send replies from multiple threads */ 78 /* RAMBlock of last request sent to source */ 79 RAMBlock *last_rb; 80 void *postcopy_tmp_page; 81 void *postcopy_tmp_zero_page; 82 /* PostCopyFD's for external userfaultfds & handlers of shared memory */ 83 GArray *postcopy_remote_fds; 84 85 QEMUBH *bh; 86 87 int state; 88 89 bool have_colo_incoming_thread; 90 QemuThread colo_incoming_thread; 91 /* The coroutine we should enter (back) after failover */ 92 Coroutine *migration_incoming_co; 93 QemuSemaphore colo_incoming_sem; 94 95 /* 96 * PostcopyBlocktimeContext to keep information for postcopy 97 * live migration, to calculate vCPU block time 98 * */ 99 struct PostcopyBlocktimeContext *blocktime_ctx; 100 101 /* notify PAUSED postcopy incoming migrations to try to continue */ 102 bool postcopy_recover_triggered; 103 QemuSemaphore postcopy_pause_sem_dst; 104 QemuSemaphore postcopy_pause_sem_fault; 105 106 /* List of listening socket addresses */ 107 SocketAddressList *socket_address_list; 108 109 /* A tree of pages that we requested to the source VM */ 110 GTree *page_requested; 111 /* For debugging purpose only, but would be nice to keep */ 112 int page_requested_count; 113 /* 114 * The mutex helps to maintain the requested pages that we sent to the 115 * source, IOW, to guarantee coherent between the page_requests tree and 116 * the per-ramblock receivedmap. Note! This does not guarantee consistency 117 * of the real page copy procedures (using UFFDIO_[ZERO]COPY). E.g., even 118 * if one bit in receivedmap is cleared, UFFDIO_COPY could have happened 119 * for that page already. This is intended so that the mutex won't 120 * serialize and blocked by slow operations like UFFDIO_* ioctls. However 121 * this should be enough to make sure the page_requested tree always 122 * contains valid information. 123 */ 124 QemuMutex page_request_mutex; 125 }; 126 127 MigrationIncomingState *migration_incoming_get_current(void); 128 void migration_incoming_state_destroy(void); 129 /* 130 * Functions to work with blocktime context 131 */ 132 void fill_destination_postcopy_migration_info(MigrationInfo *info); 133 134 #define TYPE_MIGRATION "migration" 135 136 typedef struct MigrationClass MigrationClass; 137 DECLARE_OBJ_CHECKERS(MigrationState, MigrationClass, 138 MIGRATION_OBJ, TYPE_MIGRATION) 139 140 struct MigrationClass { 141 /*< private >*/ 142 DeviceClass parent_class; 143 }; 144 145 struct MigrationState { 146 /*< private >*/ 147 DeviceState parent_obj; 148 149 /*< public >*/ 150 QemuThread thread; 151 QEMUBH *vm_start_bh; 152 QEMUBH *cleanup_bh; 153 QEMUFile *to_dst_file; 154 QIOChannelBuffer *bioc; 155 /* 156 * Protects to_dst_file pointer. We need to make sure we won't 157 * yield or hang during the critical section, since this lock will 158 * be used in OOB command handler. 159 */ 160 QemuMutex qemu_file_lock; 161 162 /* 163 * Used to allow urgent requests to override rate limiting. 164 */ 165 QemuSemaphore rate_limit_sem; 166 167 /* pages already send at the beginning of current iteration */ 168 uint64_t iteration_initial_pages; 169 170 /* pages transferred per second */ 171 double pages_per_second; 172 173 /* bytes already send at the beginning of current iteration */ 174 uint64_t iteration_initial_bytes; 175 /* time at the start of current iteration */ 176 int64_t iteration_start_time; 177 /* 178 * The final stage happens when the remaining data is smaller than 179 * this threshold; it's calculated from the requested downtime and 180 * measured bandwidth 181 */ 182 int64_t threshold_size; 183 184 /* params from 'migrate-set-parameters' */ 185 MigrationParameters parameters; 186 187 int state; 188 189 /* State related to return path */ 190 struct { 191 QEMUFile *from_dst_file; 192 QemuThread rp_thread; 193 bool error; 194 QemuSemaphore rp_sem; 195 } rp_state; 196 197 double mbps; 198 /* Timestamp when recent migration starts (ms) */ 199 int64_t start_time; 200 /* Total time used by latest migration (ms) */ 201 int64_t total_time; 202 /* Timestamp when VM is down (ms) to migrate the last stuff */ 203 int64_t downtime_start; 204 int64_t downtime; 205 int64_t expected_downtime; 206 bool enabled_capabilities[MIGRATION_CAPABILITY__MAX]; 207 int64_t setup_time; 208 /* 209 * Whether guest was running when we enter the completion stage. 210 * If migration is interrupted by any reason, we need to continue 211 * running the guest on source. 212 */ 213 bool vm_was_running; 214 215 /* Flag set once the migration has been asked to enter postcopy */ 216 bool start_postcopy; 217 /* Flag set after postcopy has sent the device state */ 218 bool postcopy_after_devices; 219 220 /* Flag set once the migration thread is running (and needs joining) */ 221 bool migration_thread_running; 222 223 /* Flag set once the migration thread called bdrv_inactivate_all */ 224 bool block_inactive; 225 226 /* Migration is waiting for guest to unplug device */ 227 QemuSemaphore wait_unplug_sem; 228 229 /* Migration is paused due to pause-before-switchover */ 230 QemuSemaphore pause_sem; 231 232 /* The semaphore is used to notify COLO thread that failover is finished */ 233 QemuSemaphore colo_exit_sem; 234 235 /* The event is used to notify COLO thread to do checkpoint */ 236 QemuEvent colo_checkpoint_event; 237 int64_t colo_checkpoint_time; 238 QEMUTimer *colo_delay_timer; 239 240 /* The first error that has occurred. 241 We used the mutex to be able to return the 1st error message */ 242 Error *error; 243 /* mutex to protect errp */ 244 QemuMutex error_mutex; 245 246 /* Do we have to clean up -b/-i from old migrate parameters */ 247 /* This feature is deprecated and will be removed */ 248 bool must_remove_block_options; 249 250 /* 251 * Global switch on whether we need to store the global state 252 * during migration. 253 */ 254 bool store_global_state; 255 256 /* Whether we send QEMU_VM_CONFIGURATION during migration */ 257 bool send_configuration; 258 /* Whether we send section footer during migration */ 259 bool send_section_footer; 260 261 /* Needed by postcopy-pause state */ 262 QemuSemaphore postcopy_pause_sem; 263 QemuSemaphore postcopy_pause_rp_sem; 264 /* 265 * Whether we abort the migration if decompression errors are 266 * detected at the destination. It is left at false for qemu 267 * older than 3.0, since only newer qemu sends streams that 268 * do not trigger spurious decompression errors. 269 */ 270 bool decompress_error_check; 271 272 /* 273 * This decides the size of guest memory chunk that will be used 274 * to track dirty bitmap clearing. The size of memory chunk will 275 * be GUEST_PAGE_SIZE << N. Say, N=0 means we will clear dirty 276 * bitmap for each page to send (1<<0=1); N=10 means we will clear 277 * dirty bitmap only once for 1<<10=1K continuous guest pages 278 * (which is in 4M chunk). 279 */ 280 uint8_t clear_bitmap_shift; 281 282 /* 283 * This save hostname when out-going migration starts 284 */ 285 char *hostname; 286 }; 287 288 void migrate_set_state(int *state, int old_state, int new_state); 289 290 void migration_fd_process_incoming(QEMUFile *f, Error **errp); 291 void migration_ioc_process_incoming(QIOChannel *ioc, Error **errp); 292 void migration_incoming_process(void); 293 294 bool migration_has_all_channels(void); 295 296 uint64_t migrate_max_downtime(void); 297 298 void migrate_set_error(MigrationState *s, const Error *error); 299 void migrate_fd_error(MigrationState *s, const Error *error); 300 301 void migrate_fd_connect(MigrationState *s, Error *error_in); 302 303 bool migration_is_setup_or_active(int state); 304 bool migration_is_running(int state); 305 306 void migrate_init(MigrationState *s); 307 bool migration_is_blocked(Error **errp); 308 /* True if outgoing migration has entered postcopy phase */ 309 bool migration_in_postcopy(void); 310 MigrationState *migrate_get_current(void); 311 312 bool migrate_postcopy(void); 313 314 bool migrate_release_ram(void); 315 bool migrate_postcopy_ram(void); 316 bool migrate_zero_blocks(void); 317 bool migrate_dirty_bitmaps(void); 318 bool migrate_ignore_shared(void); 319 bool migrate_validate_uuid(void); 320 321 bool migrate_auto_converge(void); 322 bool migrate_use_multifd(void); 323 bool migrate_pause_before_switchover(void); 324 int migrate_multifd_channels(void); 325 MultiFDCompression migrate_multifd_compression(void); 326 int migrate_multifd_zlib_level(void); 327 int migrate_multifd_zstd_level(void); 328 329 int migrate_use_xbzrle(void); 330 uint64_t migrate_xbzrle_cache_size(void); 331 bool migrate_colo_enabled(void); 332 333 bool migrate_use_block(void); 334 bool migrate_use_block_incremental(void); 335 int migrate_max_cpu_throttle(void); 336 bool migrate_use_return_path(void); 337 338 uint64_t ram_get_total_transferred_pages(void); 339 340 bool migrate_use_compression(void); 341 int migrate_compress_level(void); 342 int migrate_compress_threads(void); 343 int migrate_compress_wait_thread(void); 344 int migrate_decompress_threads(void); 345 bool migrate_use_events(void); 346 bool migrate_postcopy_blocktime(void); 347 bool migrate_background_snapshot(void); 348 349 /* Sending on the return path - generic and then for each message type */ 350 void migrate_send_rp_shut(MigrationIncomingState *mis, 351 uint32_t value); 352 void migrate_send_rp_pong(MigrationIncomingState *mis, 353 uint32_t value); 354 int migrate_send_rp_req_pages(MigrationIncomingState *mis, RAMBlock *rb, 355 ram_addr_t start, uint64_t haddr); 356 int migrate_send_rp_message_req_pages(MigrationIncomingState *mis, 357 RAMBlock *rb, ram_addr_t start); 358 void migrate_send_rp_recv_bitmap(MigrationIncomingState *mis, 359 char *block_name); 360 void migrate_send_rp_resume_ack(MigrationIncomingState *mis, uint32_t value); 361 362 void dirty_bitmap_mig_before_vm_start(void); 363 void dirty_bitmap_mig_cancel_outgoing(void); 364 void dirty_bitmap_mig_cancel_incoming(void); 365 bool check_dirty_bitmap_mig_alias_map(const BitmapMigrationNodeAliasList *bbm, 366 Error **errp); 367 368 void migrate_add_address(SocketAddress *address); 369 370 int foreach_not_ignored_block(RAMBlockIterFunc func, void *opaque); 371 372 #define qemu_ram_foreach_block \ 373 #warning "Use foreach_not_ignored_block in migration code" 374 375 void migration_make_urgent_request(void); 376 void migration_consume_urgent_request(void); 377 bool migration_rate_limit(void); 378 379 #endif 380