include/migration/migration.h

   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 "qapi/qmp/qdict.h"
  18 #include "qemu-common.h"
  19 #include "qemu/thread.h"
  20 #include "qemu/notify.h"
  21 #include "migration/vmstate.h"
  22 #include "qapi-types.h"
  23 #include "exec/cpu-common.h"
  24 #include "qemu/coroutine_int.h"
  25
  26 #define QEMU_VM_FILE_MAGIC           0x5145564d
  27 #define QEMU_VM_FILE_VERSION_COMPAT  0x00000002
  28 #define QEMU_VM_FILE_VERSION         0x00000003
  29
  30 #define QEMU_VM_EOF                  0x00
  31 #define QEMU_VM_SECTION_START        0x01
  32 #define QEMU_VM_SECTION_PART         0x02
  33 #define QEMU_VM_SECTION_END          0x03
  34 #define QEMU_VM_SECTION_FULL         0x04
  35 #define QEMU_VM_SUBSECTION           0x05
  36 #define QEMU_VM_VMDESCRIPTION        0x06
  37 #define QEMU_VM_CONFIGURATION        0x07
  38 #define QEMU_VM_COMMAND              0x08
  39 #define QEMU_VM_SECTION_FOOTER       0x7e
  40
  41 /* for vl.c */
  42 extern int only_migratable;
  43
  44 struct MigrationParams {
  45     bool blk;
  46     bool shared;
  47 };
  48
  49 /* Messages sent on the return path from destination to source */
  50 enum mig_rp_message_type {
  51     MIG_RP_MSG_INVALID = 0,  /* Must be 0 */
  52     MIG_RP_MSG_SHUT,         /* sibling will not send any more RP messages */
  53     MIG_RP_MSG_PONG,         /* Response to a PING; data (seq: be32 ) */
  54
  55     MIG_RP_MSG_REQ_PAGES_ID, /* data (start: be64, len: be32, id: string) */
  56     MIG_RP_MSG_REQ_PAGES,    /* data (start: be64, len: be32) */
  57
  58     MIG_RP_MSG_MAX
  59 };
  60
  61 typedef QLIST_HEAD(, LoadStateEntry) LoadStateEntry_Head;
  62
  63 /* The current postcopy state is read/set by postcopy_state_get/set
  64  * which update it atomically.
  65  * The state is updated as postcopy messages are received, and
  66  * in general only one thread should be writing to the state at any one
  67  * time, initially the main thread and then the listen thread;
  68  * Corner cases are where either thread finishes early and/or errors.
  69  * The state is checked as messages are received to ensure that
  70  * the source is sending us messages in the correct order.
  71  * The state is also used by the RAM reception code to know if it
  72  * has to place pages atomically, and the cleanup code at the end of
  73  * the main thread to know if it has to delay cleanup until the end
  74  * of postcopy.
  75  */
  76 typedef enum {
  77     POSTCOPY_INCOMING_NONE = 0,  /* Initial state - no postcopy */
  78     POSTCOPY_INCOMING_ADVISE,
  79     POSTCOPY_INCOMING_DISCARD,
  80     POSTCOPY_INCOMING_LISTENING,
  81     POSTCOPY_INCOMING_RUNNING,
  82     POSTCOPY_INCOMING_END
  83 } PostcopyState;
  84
  85 /* State for the incoming migration */
  86 struct MigrationIncomingState {
  87     QEMUFile *from_src_file;
  88
  89     /*
  90      * Free at the start of the main state load, set as the main thread finishes
  91      * loading state.
  92      */
  93     QemuEvent main_thread_load_event;
  94
  95     bool           have_fault_thread;
  96     QemuThread     fault_thread;
  97     QemuSemaphore  fault_thread_sem;
  98
  99     bool           have_listen_thread;
 100     QemuThread     listen_thread;
 101     QemuSemaphore  listen_thread_sem;
 102
 103     /* For the kernel to send us notifications */
 104     int       userfault_fd;
 105     /* To tell the fault_thread to quit */
 106     int       userfault_quit_fd;
 107     QEMUFile *to_src_file;
 108     QemuMutex rp_mutex;    /* We send replies from multiple threads */
 109     void     *postcopy_tmp_page;
 110
 111     QEMUBH *bh;
 112
 113     int state;
 114
 115     bool have_colo_incoming_thread;
 116     QemuThread colo_incoming_thread;
 117     /* The coroutine we should enter (back) after failover */
 118     Coroutine *migration_incoming_co;
 119     QemuSemaphore colo_incoming_sem;
 120
 121     /* See savevm.c */
 122     LoadStateEntry_Head loadvm_handlers;
 123 };
 124
 125 MigrationIncomingState *migration_incoming_get_current(void);
 126 void migration_incoming_state_destroy(void);
 127
 128 /*
 129  * An outstanding page request, on the source, having been received
 130  * and queued
 131  */
 132 struct MigrationSrcPageRequest {
 133     RAMBlock *rb;
 134     hwaddr    offset;
 135     hwaddr    len;
 136
 137     QSIMPLEQ_ENTRY(MigrationSrcPageRequest) next_req;
 138 };
 139
 140 struct MigrationState
 141 {
 142     size_t bytes_xfer;
 143     size_t xfer_limit;
 144     QemuThread thread;
 145     QEMUBH *cleanup_bh;
 146     QEMUFile *to_dst_file;
 147
 148     /* New style params from 'migrate-set-parameters' */
 149     MigrationParameters parameters;
 150
 151     int state;
 152     /* Old style params from 'migrate' command */
 153     MigrationParams params;
 154
 155     /* State related to return path */
 156     struct {
 157         QEMUFile     *from_dst_file;
 158         QemuThread    rp_thread;
 159         bool          error;
 160     } rp_state;
 161
 162     double mbps;
 163     int64_t total_time;
 164     int64_t downtime;
 165     int64_t expected_downtime;
 166     int64_t dirty_pages_rate;
 167     int64_t dirty_bytes_rate;
 168     bool enabled_capabilities[MIGRATION_CAPABILITY__MAX];
 169     int64_t xbzrle_cache_size;
 170     int64_t setup_time;
 171     int64_t dirty_sync_count;
 172     /* Count of requests incoming from destination */
 173     int64_t postcopy_requests;
 174
 175     /* Flag set once the migration has been asked to enter postcopy */
 176     bool start_postcopy;
 177     /* Flag set after postcopy has sent the device state */
 178     bool postcopy_after_devices;
 179
 180     /* Flag set once the migration thread is running (and needs joining) */
 181     bool migration_thread_running;
 182
 183     /* Flag set once the migration thread called bdrv_inactivate_all */
 184     bool block_inactive;
 185
 186     /* Queue of outstanding page requests from the destination */
 187     QemuMutex src_page_req_mutex;
 188     QSIMPLEQ_HEAD(src_page_requests, MigrationSrcPageRequest) src_page_requests;
 189     /* The RAMBlock used in the last src_page_request */
 190     RAMBlock *last_req_rb;
 191     /* The semaphore is used to notify COLO thread that failover is finished */
 192     QemuSemaphore colo_exit_sem;
 193
 194     /* The semaphore is used to notify COLO thread to do checkpoint */
 195     QemuSemaphore colo_checkpoint_sem;
 196     int64_t colo_checkpoint_time;
 197     QEMUTimer *colo_delay_timer;
 198
 199     /* The last error that occurred */
 200     Error *error;
 201 };
 202
 203 void migrate_set_state(int *state, int old_state, int new_state);
 204
 205 void migration_fd_process_incoming(QEMUFile *f);
 206
 207 void qemu_start_incoming_migration(const char *uri, Error **errp);
 208
 209 void migration_channel_process_incoming(MigrationState *s,
 210                                         QIOChannel *ioc);
 211
 212 void migration_tls_channel_process_incoming(MigrationState *s,
 213                                             QIOChannel *ioc,
 214                                             Error **errp);
 215
 216 void migration_channel_connect(MigrationState *s,
 217                                QIOChannel *ioc,
 218                                const char *hostname);
 219
 220 void migration_tls_channel_connect(MigrationState *s,
 221                                    QIOChannel *ioc,
 222                                    const char *hostname,
 223                                    Error **errp);
 224
 225 uint64_t migrate_max_downtime(void);
 226
 227 void exec_start_incoming_migration(const char *host_port, Error **errp);
 228
 229 void exec_start_outgoing_migration(MigrationState *s, const char *host_port, Error **errp);
 230
 231 void tcp_start_incoming_migration(const char *host_port, Error **errp);
 232
 233 void tcp_start_outgoing_migration(MigrationState *s, const char *host_port, Error **errp);
 234
 235 void unix_start_incoming_migration(const char *path, Error **errp);
 236
 237 void unix_start_outgoing_migration(MigrationState *s, const char *path, Error **errp);
 238
 239 void fd_start_incoming_migration(const char *path, Error **errp);
 240
 241 void fd_start_outgoing_migration(MigrationState *s, const char *fdname, Error **errp);
 242
 243 void rdma_start_outgoing_migration(void *opaque, const char *host_port, Error **errp);
 244
 245 void rdma_start_incoming_migration(const char *host_port, Error **errp);
 246
 247 void migrate_fd_error(MigrationState *s, const Error *error);
 248
 249 void migrate_fd_connect(MigrationState *s);
 250
 251 void add_migration_state_change_notifier(Notifier *notify);
 252 void remove_migration_state_change_notifier(Notifier *notify);
 253 MigrationState *migrate_init(const MigrationParams *params);
 254 bool migration_is_blocked(Error **errp);
 255 bool migration_in_setup(MigrationState *);
 256 bool migration_is_idle(MigrationState *s);
 257 bool migration_has_finished(MigrationState *);
 258 bool migration_has_failed(MigrationState *);
 259 /* True if outgoing migration has entered postcopy phase */
 260 bool migration_in_postcopy(MigrationState *);
 261 /* ...and after the device transmission */
 262 bool migration_in_postcopy_after_devices(MigrationState *);
 263 MigrationState *migrate_get_current(void);
 264
 265 void migrate_compress_threads_create(void);
 266 void migrate_compress_threads_join(void);
 267 void migrate_decompress_threads_create(void);
 268 void migrate_decompress_threads_join(void);
 269 uint64_t ram_bytes_remaining(void);
 270 uint64_t ram_bytes_transferred(void);
 271 uint64_t ram_bytes_total(void);
 272 void free_xbzrle_decoded_buf(void);
 273
 274 void acct_update_position(QEMUFile *f, size_t size, bool zero);
 275
 276 uint64_t dup_mig_bytes_transferred(void);
 277 uint64_t dup_mig_pages_transferred(void);
 278 uint64_t skipped_mig_bytes_transferred(void);
 279 uint64_t skipped_mig_pages_transferred(void);
 280 uint64_t norm_mig_bytes_transferred(void);
 281 uint64_t norm_mig_pages_transferred(void);
 282 uint64_t xbzrle_mig_bytes_transferred(void);
 283 uint64_t xbzrle_mig_pages_transferred(void);
 284 uint64_t xbzrle_mig_pages_overflow(void);
 285 uint64_t xbzrle_mig_pages_cache_miss(void);
 286 double xbzrle_mig_cache_miss_rate(void);
 287
 288 void ram_handle_compressed(void *host, uint8_t ch, uint64_t size);
 289 void ram_debug_dump_bitmap(unsigned long *todump, bool expected);
 290 /* For outgoing discard bitmap */
 291 int ram_postcopy_send_discard_bitmap(MigrationState *ms);
 292 /* For incoming postcopy discard */
 293 int ram_discard_range(MigrationIncomingState *mis, const char *block_name,
 294                       uint64_t start, size_t length);
 295 int ram_postcopy_incoming_init(MigrationIncomingState *mis);
 296 void ram_postcopy_migrated_memory_release(MigrationState *ms);
 297
 298 /**
 299  * @migrate_add_blocker - prevent migration from proceeding
 300  *
 301  * @reason - an error to be returned whenever migration is attempted
 302  *
 303  * @errp - [out] The reason (if any) we cannot block migration right now.
 304  *
 305  * @returns - 0 on success, -EBUSY/-EACCES on failure, with errp set.
 306  */
 307 int migrate_add_blocker(Error *reason, Error **errp);
 308
 309 /**
 310  * @migrate_del_blocker - remove a blocking error from migration
 311  *
 312  * @reason - the error blocking migration
 313  */
 314 void migrate_del_blocker(Error *reason);
 315
 316 bool migrate_release_ram(void);
 317 bool migrate_postcopy_ram(void);
 318 bool migrate_zero_blocks(void);
 319
 320 bool migrate_auto_converge(void);
 321
 322 int xbzrle_encode_buffer(uint8_t *old_buf, uint8_t *new_buf, int slen,
 323                          uint8_t *dst, int dlen);
 324 int xbzrle_decode_buffer(uint8_t *src, int slen, uint8_t *dst, int dlen);
 325
 326 int migrate_use_xbzrle(void);
 327 int64_t migrate_xbzrle_cache_size(void);
 328 bool migrate_colo_enabled(void);
 329
 330 int64_t xbzrle_cache_resize(int64_t new_size);
 331
 332 bool migrate_use_compression(void);
 333 int migrate_compress_level(void);
 334 int migrate_compress_threads(void);
 335 int migrate_decompress_threads(void);
 336 bool migrate_use_events(void);
 337
 338 /* Sending on the return path - generic and then for each message type */
 339 void migrate_send_rp_message(MigrationIncomingState *mis,
 340                              enum mig_rp_message_type message_type,
 341                              uint16_t len, void *data);
 342 void migrate_send_rp_shut(MigrationIncomingState *mis,
 343                           uint32_t value);
 344 void migrate_send_rp_pong(MigrationIncomingState *mis,
 345                           uint32_t value);
 346 void migrate_send_rp_req_pages(MigrationIncomingState *mis, const char* rbname,
 347                               ram_addr_t start, size_t len);
 348
 349 void ram_control_before_iterate(QEMUFile *f, uint64_t flags);
 350 void ram_control_after_iterate(QEMUFile *f, uint64_t flags);
 351 void ram_control_load_hook(QEMUFile *f, uint64_t flags, void *data);
 352
 353 /* Whenever this is found in the data stream, the flags
 354  * will be passed to ram_control_load_hook in the incoming-migration
 355  * side. This lets before_ram_iterate/after_ram_iterate add
 356  * transport-specific sections to the RAM migration data.
 357  */
 358 #define RAM_SAVE_FLAG_HOOK     0x80
 359
 360 #define RAM_SAVE_CONTROL_NOT_SUPP -1000
 361 #define RAM_SAVE_CONTROL_DELAYED  -2000
 362
 363 size_t ram_control_save_page(QEMUFile *f, ram_addr_t block_offset,
 364                              ram_addr_t offset, size_t size,
 365                              uint64_t *bytes_sent);
 366
 367 void ram_mig_init(void);
 368 void savevm_skip_section_footers(void);
 369 void register_global_state(void);
 370 void global_state_set_optional(void);
 371 void savevm_skip_configuration(void);
 372 int global_state_store(void);
 373 void global_state_store_running(void);
 374
 375 void flush_page_queue(MigrationState *ms);
 376 int ram_save_queue_pages(MigrationState *ms, const char *rbname,
 377                          ram_addr_t start, ram_addr_t len);
 378
 379 PostcopyState postcopy_state_get(void);
 380 /* Set the state and return the old state */
 381 PostcopyState postcopy_state_set(PostcopyState new_state);
 382 #endif