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