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