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 #include "qom/object.h"
  26
  27 #define QEMU_VM_FILE_MAGIC           0x5145564d
  28 #define QEMU_VM_FILE_VERSION_COMPAT  0x00000002
  29 #define QEMU_VM_FILE_VERSION         0x00000003
  30
  31 #define QEMU_VM_EOF                  0x00
  32 #define QEMU_VM_SECTION_START        0x01
  33 #define QEMU_VM_SECTION_PART         0x02
  34 #define QEMU_VM_SECTION_END          0x03
  35 #define QEMU_VM_SECTION_FULL         0x04
  36 #define QEMU_VM_SUBSECTION           0x05
  37 #define QEMU_VM_VMDESCRIPTION        0x06
  38 #define QEMU_VM_CONFIGURATION        0x07
  39 #define QEMU_VM_COMMAND              0x08
  40 #define QEMU_VM_SECTION_FOOTER       0x7e
  41
  42 /* for vl.c */
  43 extern int only_migratable;
  44
  45 struct MigrationParams {
  46     bool blk;
  47     bool shared;
  48 };
  49
  50 /* Messages sent on the return path from destination to source */
  51 enum mig_rp_message_type {
  52     MIG_RP_MSG_INVALID = 0,  /* Must be 0 */
  53     MIG_RP_MSG_SHUT,         /* sibling will not send any more RP messages */
  54     MIG_RP_MSG_PONG,         /* Response to a PING; data (seq: be32 ) */
  55
  56     MIG_RP_MSG_REQ_PAGES_ID, /* data (start: be64, len: be32, id: string) */
  57     MIG_RP_MSG_REQ_PAGES,    /* data (start: be64, len: be32) */
  58
  59     MIG_RP_MSG_MAX
  60 };
  61
  62 typedef QLIST_HEAD(, LoadStateEntry) LoadStateEntry_Head;
  63
  64 /* The current postcopy state is read/set by postcopy_state_get/set
  65  * which update it atomically.
  66  * The state is updated as postcopy messages are received, and
  67  * in general only one thread should be writing to the state at any one
  68  * time, initially the main thread and then the listen thread;
  69  * Corner cases are where either thread finishes early and/or errors.
  70  * The state is checked as messages are received to ensure that
  71  * the source is sending us messages in the correct order.
  72  * The state is also used by the RAM reception code to know if it
  73  * has to place pages atomically, and the cleanup code at the end of
  74  * the main thread to know if it has to delay cleanup until the end
  75  * of postcopy.
  76  */
  77 typedef enum {
  78     POSTCOPY_INCOMING_NONE = 0,  /* Initial state - no postcopy */
  79     POSTCOPY_INCOMING_ADVISE,
  80     POSTCOPY_INCOMING_DISCARD,
  81     POSTCOPY_INCOMING_LISTENING,
  82     POSTCOPY_INCOMING_RUNNING,
  83     POSTCOPY_INCOMING_END
  84 } PostcopyState;
  85
  86 /* State for the incoming migration */
  87 struct MigrationIncomingState {
  88     QEMUFile *from_src_file;
  89
  90     /*
  91      * Free at the start of the main state load, set as the main thread finishes
  92      * loading state.
  93      */
  94     QemuEvent main_thread_load_event;
  95
  96     size_t         largest_page_size;
  97     bool           have_fault_thread;
  98     QemuThread     fault_thread;
  99     QemuSemaphore  fault_thread_sem;
 100
 101     bool           have_listen_thread;
 102     QemuThread     listen_thread;
 103     QemuSemaphore  listen_thread_sem;
 104
 105     /* For the kernel to send us notifications */
 106     int       userfault_fd;
 107     /* To tell the fault_thread to quit */
 108     int       userfault_quit_fd;
 109     QEMUFile *to_src_file;
 110     QemuMutex rp_mutex;    /* We send replies from multiple threads */
 111     void     *postcopy_tmp_page;
 112     void     *postcopy_tmp_zero_page;
 113
 114     QEMUBH *bh;
 115
 116     int state;
 117
 118     bool have_colo_incoming_thread;
 119     QemuThread colo_incoming_thread;
 120     /* The coroutine we should enter (back) after failover */
 121     Coroutine *migration_incoming_co;
 122     QemuSemaphore colo_incoming_sem;
 123
 124     /* See savevm.c */
 125     LoadStateEntry_Head loadvm_handlers;
 126 };
 127
 128 MigrationIncomingState *migration_incoming_get_current(void);
 129 void migration_incoming_state_destroy(void);
 130
 131 /*
 132  * An outstanding page request, on the source, having been received
 133  * and queued
 134  */
 135 struct MigrationSrcPageRequest {
 136     RAMBlock *rb;
 137     hwaddr    offset;
 138     hwaddr    len;
 139
 140     QSIMPLEQ_ENTRY(MigrationSrcPageRequest) next_req;
 141 };
 142
 143 struct MigrationState
 144 {
 145     size_t bytes_xfer;
 146     size_t xfer_limit;
 147     QemuThread thread;
 148     QEMUBH *cleanup_bh;
 149     QEMUFile *to_dst_file;
 150
 151     /* New style params from 'migrate-set-parameters' */
 152     MigrationParameters parameters;
 153
 154     int state;
 155     /* Old style params from 'migrate' command */
 156     MigrationParams params;
 157
 158     /* State related to return path */
 159     struct {
 160         QEMUFile     *from_dst_file;
 161         QemuThread    rp_thread;
 162         bool          error;
 163     } rp_state;
 164
 165     double mbps;
 166     int64_t total_time;
 167     int64_t downtime;
 168     int64_t expected_downtime;
 169     int64_t dirty_pages_rate;
 170     int64_t dirty_bytes_rate;
 171     bool enabled_capabilities[MIGRATION_CAPABILITY__MAX];
 172     int64_t xbzrle_cache_size;
 173     int64_t setup_time;
 174     int64_t dirty_sync_count;
 175     /* Count of requests incoming from destination */
 176     int64_t postcopy_requests;
 177
 178     /* Flag set once the migration has been asked to enter postcopy */
 179     bool start_postcopy;
 180     /* Flag set after postcopy has sent the device state */
 181     bool postcopy_after_devices;
 182
 183     /* Flag set once the migration thread is running (and needs joining) */
 184     bool migration_thread_running;
 185
 186     /* Flag set once the migration thread called bdrv_inactivate_all */
 187     bool block_inactive;
 188
 189     /* Queue of outstanding page requests from the destination */
 190     QemuMutex src_page_req_mutex;
 191     QSIMPLEQ_HEAD(src_page_requests, MigrationSrcPageRequest) src_page_requests;
 192     /* The RAMBlock used in the last src_page_request */
 193     RAMBlock *last_req_rb;
 194     /* The semaphore is used to notify COLO thread that failover is finished */
 195     QemuSemaphore colo_exit_sem;
 196
 197     /* The semaphore is used to notify COLO thread to do checkpoint */
 198     QemuSemaphore colo_checkpoint_sem;
 199     int64_t colo_checkpoint_time;
 200     QEMUTimer *colo_delay_timer;
 201
 202     /* The last error that occurred */
 203     Error *error;
 204 };
 205
 206 void migrate_set_state(int *state, int old_state, int new_state);
 207
 208 void migration_fd_process_incoming(QEMUFile *f);
 209
 210 void qemu_start_incoming_migration(const char *uri, Error **errp);
 211
 212 void migration_channel_process_incoming(MigrationState *s,
 213                                         QIOChannel *ioc);
 214
 215 void migration_tls_channel_process_incoming(MigrationState *s,
 216                                             QIOChannel *ioc,
 217                                             Error **errp);
 218
 219 void migration_channel_connect(MigrationState *s,
 220                                QIOChannel *ioc,
 221                                const char *hostname);
 222
 223 void migration_tls_channel_connect(MigrationState *s,
 224                                    QIOChannel *ioc,
 225                                    const char *hostname,
 226                                    Error **errp);
 227
 228 uint64_t migrate_max_downtime(void);
 229
 230 void exec_start_incoming_migration(const char *host_port, Error **errp);
 231
 232 void exec_start_outgoing_migration(MigrationState *s, const char *host_port, Error **errp);
 233
 234 void tcp_start_incoming_migration(const char *host_port, Error **errp);
 235
 236 void tcp_start_outgoing_migration(MigrationState *s, const char *host_port, Error **errp);
 237
 238 void unix_start_incoming_migration(const char *path, Error **errp);
 239
 240 void unix_start_outgoing_migration(MigrationState *s, const char *path, Error **errp);
 241
 242 void fd_start_incoming_migration(const char *path, Error **errp);
 243
 244 void fd_start_outgoing_migration(MigrationState *s, const char *fdname, Error **errp);
 245
 246 void rdma_start_outgoing_migration(void *opaque, const char *host_port, Error **errp);
 247
 248 void rdma_start_incoming_migration(const char *host_port, Error **errp);
 249
 250 void migrate_fd_error(MigrationState *s, const Error *error);
 251
 252 void migrate_fd_connect(MigrationState *s);
 253
 254 void add_migration_state_change_notifier(Notifier *notify);
 255 void remove_migration_state_change_notifier(Notifier *notify);
 256 MigrationState *migrate_init(const MigrationParams *params);
 257 bool migration_is_blocked(Error **errp);
 258 bool migration_in_setup(MigrationState *);
 259 bool migration_is_idle(MigrationState *s);
 260 bool migration_has_finished(MigrationState *);
 261 bool migration_has_failed(MigrationState *);
 262 /* True if outgoing migration has entered postcopy phase */
 263 bool migration_in_postcopy(MigrationState *);
 264 /* ...and after the device transmission */
 265 bool migration_in_postcopy_after_devices(MigrationState *);
 266 MigrationState *migrate_get_current(void);
 267
 268 void migrate_compress_threads_create(void);
 269 void migrate_compress_threads_join(void);
 270 void migrate_decompress_threads_create(void);
 271 void migrate_decompress_threads_join(void);
 272 uint64_t ram_bytes_remaining(void);
 273 uint64_t ram_bytes_transferred(void);
 274 uint64_t ram_bytes_total(void);
 275 void free_xbzrle_decoded_buf(void);
 276
 277 void acct_update_position(QEMUFile *f, size_t size, bool zero);
 278
 279 uint64_t dup_mig_bytes_transferred(void);
 280 uint64_t dup_mig_pages_transferred(void);
 281 uint64_t skipped_mig_bytes_transferred(void);
 282 uint64_t skipped_mig_pages_transferred(void);
 283 uint64_t norm_mig_bytes_transferred(void);
 284 uint64_t norm_mig_pages_transferred(void);
 285 uint64_t xbzrle_mig_bytes_transferred(void);
 286 uint64_t xbzrle_mig_pages_transferred(void);
 287 uint64_t xbzrle_mig_pages_overflow(void);
 288 uint64_t xbzrle_mig_pages_cache_miss(void);
 289 double xbzrle_mig_cache_miss_rate(void);
 290
 291 void ram_handle_compressed(void *host, uint8_t ch, uint64_t size);
 292 void ram_debug_dump_bitmap(unsigned long *todump, bool expected);
 293 /* For outgoing discard bitmap */
 294 int ram_postcopy_send_discard_bitmap(MigrationState *ms);
 295 /* For incoming postcopy discard */
 296 int ram_discard_range(MigrationIncomingState *mis, const char *block_name,
 297                       uint64_t start, size_t length);
 298 int ram_postcopy_incoming_init(MigrationIncomingState *mis);
 299 void ram_postcopy_migrated_memory_release(MigrationState *ms);
 300
 301 /**
 302  * @migrate_add_blocker - prevent migration from proceeding
 303  *
 304  * @reason - an error to be returned whenever migration is attempted
 305  *
 306  * @errp - [out] The reason (if any) we cannot block migration right now.
 307  *
 308  * @returns - 0 on success, -EBUSY/-EACCES on failure, with errp set.
 309  */
 310 int migrate_add_blocker(Error *reason, Error **errp);
 311
 312 /**
 313  * @migrate_del_blocker - remove a blocking error from migration
 314  *
 315  * @reason - the error blocking migration
 316  */
 317 void migrate_del_blocker(Error *reason);
 318
 319 int check_migratable(Object *obj, Error **err);
 320
 321 bool migrate_release_ram(void);
 322 bool migrate_postcopy_ram(void);
 323 bool migrate_zero_blocks(void);
 324
 325 bool migrate_auto_converge(void);
 326
 327 int xbzrle_encode_buffer(uint8_t *old_buf, uint8_t *new_buf, int slen,
 328                          uint8_t *dst, int dlen);
 329 int xbzrle_decode_buffer(uint8_t *src, int slen, uint8_t *dst, int dlen);
 330
 331 int migrate_use_xbzrle(void);
 332 int64_t migrate_xbzrle_cache_size(void);
 333 bool migrate_colo_enabled(void);
 334
 335 int64_t xbzrle_cache_resize(int64_t new_size);
 336
 337 bool migrate_use_compression(void);
 338 int migrate_compress_level(void);
 339 int migrate_compress_threads(void);
 340 int migrate_decompress_threads(void);
 341 bool migrate_use_events(void);
 342
 343 /* Sending on the return path - generic and then for each message type */
 344 void migrate_send_rp_message(MigrationIncomingState *mis,
 345                              enum mig_rp_message_type message_type,
 346                              uint16_t len, void *data);
 347 void migrate_send_rp_shut(MigrationIncomingState *mis,
 348                           uint32_t value);
 349 void migrate_send_rp_pong(MigrationIncomingState *mis,
 350                           uint32_t value);
 351 void migrate_send_rp_req_pages(MigrationIncomingState *mis, const char* rbname,
 352                               ram_addr_t start, size_t len);
 353
 354 void ram_control_before_iterate(QEMUFile *f, uint64_t flags);
 355 void ram_control_after_iterate(QEMUFile *f, uint64_t flags);
 356 void ram_control_load_hook(QEMUFile *f, uint64_t flags, void *data);
 357
 358 /* Whenever this is found in the data stream, the flags
 359  * will be passed to ram_control_load_hook in the incoming-migration
 360  * side. This lets before_ram_iterate/after_ram_iterate add
 361  * transport-specific sections to the RAM migration data.
 362  */
 363 #define RAM_SAVE_FLAG_HOOK     0x80
 364
 365 #define RAM_SAVE_CONTROL_NOT_SUPP -1000
 366 #define RAM_SAVE_CONTROL_DELAYED  -2000
 367
 368 size_t ram_control_save_page(QEMUFile *f, ram_addr_t block_offset,
 369                              ram_addr_t offset, size_t size,
 370                              uint64_t *bytes_sent);
 371
 372 void ram_mig_init(void);
 373 void savevm_skip_section_footers(void);
 374 void register_global_state(void);
 375 void global_state_set_optional(void);
 376 void savevm_skip_configuration(void);
 377 int global_state_store(void);
 378 void global_state_store_running(void);
 379
 380 void flush_page_queue(MigrationState *ms);
 381 int ram_save_queue_pages(MigrationState *ms, const char *rbname,
 382                          ram_addr_t start, ram_addr_t len);
 383 uint64_t ram_pagesize_summary(void);
 384
 385 PostcopyState postcopy_state_get(void);
 386 /* Set the state and return the old state */
 387 PostcopyState postcopy_state_set(PostcopyState new_state);
 388 #endif