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
 120     /* See savevm.c */
 121     LoadStateEntry_Head loadvm_handlers;
 122 };
 123
 124 MigrationIncomingState *migration_incoming_get_current(void);
 125 void migration_incoming_state_destroy(void);
 126
 127 /*
 128  * An outstanding page request, on the source, having been received
 129  * and queued
 130  */
 131 struct MigrationSrcPageRequest {
 132     RAMBlock *rb;
 133     hwaddr    offset;
 134     hwaddr    len;
 135
 136     QSIMPLEQ_ENTRY(MigrationSrcPageRequest) next_req;
 137 };
 138
 139 struct MigrationState
 140 {
 141     size_t bytes_xfer;
 142     size_t xfer_limit;
 143     QemuThread thread;
 144     QEMUBH *cleanup_bh;
 145     QEMUFile *to_dst_file;
 146
 147     /* New style params from 'migrate-set-parameters' */
 148     MigrationParameters parameters;
 149
 150     int state;
 151     /* Old style params from 'migrate' command */
 152     MigrationParams params;
 153
 154     /* State related to return path */
 155     struct {
 156         QEMUFile     *from_dst_file;
 157         QemuThread    rp_thread;
 158         bool          error;
 159     } rp_state;
 160
 161     double mbps;
 162     int64_t total_time;
 163     int64_t downtime;
 164     int64_t expected_downtime;
 165     int64_t dirty_pages_rate;
 166     int64_t dirty_bytes_rate;
 167     bool enabled_capabilities[MIGRATION_CAPABILITY__MAX];
 168     int64_t xbzrle_cache_size;
 169     int64_t setup_time;
 170     int64_t dirty_sync_count;
 171     /* Count of requests incoming from destination */
 172     int64_t postcopy_requests;
 173
 174     /* Flag set once the migration has been asked to enter postcopy */
 175     bool start_postcopy;
 176     /* Flag set after postcopy has sent the device state */
 177     bool postcopy_after_devices;
 178
 179     /* Flag set once the migration thread is running (and needs joining) */
 180     bool migration_thread_running;
 181
 182     /* Flag set once the migration thread called bdrv_inactivate_all */
 183     bool block_inactive;
 184
 185     /* Queue of outstanding page requests from the destination */
 186     QemuMutex src_page_req_mutex;
 187     QSIMPLEQ_HEAD(src_page_requests, MigrationSrcPageRequest) src_page_requests;
 188     /* The RAMBlock used in the last src_page_request */
 189     RAMBlock *last_req_rb;
 190
 191     /* The semaphore is used to notify COLO thread to do checkpoint */
 192     QemuSemaphore colo_checkpoint_sem;
 193     int64_t colo_checkpoint_time;
 194     QEMUTimer *colo_delay_timer;
 195
 196     /* The last error that occurred */
 197     Error *error;
 198 };
 199
 200 void migrate_set_state(int *state, int old_state, int new_state);
 201
 202 void migration_fd_process_incoming(QEMUFile *f);
 203
 204 void qemu_start_incoming_migration(const char *uri, Error **errp);
 205
 206 void migration_channel_process_incoming(MigrationState *s,
 207                                         QIOChannel *ioc);
 208
 209 void migration_tls_channel_process_incoming(MigrationState *s,
 210                                             QIOChannel *ioc,
 211                                             Error **errp);
 212
 213 void migration_channel_connect(MigrationState *s,
 214                                QIOChannel *ioc,
 215                                const char *hostname);
 216
 217 void migration_tls_channel_connect(MigrationState *s,
 218                                    QIOChannel *ioc,
 219                                    const char *hostname,
 220                                    Error **errp);
 221
 222 uint64_t migrate_max_downtime(void);
 223
 224 void exec_start_incoming_migration(const char *host_port, Error **errp);
 225
 226 void exec_start_outgoing_migration(MigrationState *s, const char *host_port, Error **errp);
 227
 228 void tcp_start_incoming_migration(const char *host_port, Error **errp);
 229
 230 void tcp_start_outgoing_migration(MigrationState *s, const char *host_port, Error **errp);
 231
 232 void unix_start_incoming_migration(const char *path, Error **errp);
 233
 234 void unix_start_outgoing_migration(MigrationState *s, const char *path, Error **errp);
 235
 236 void fd_start_incoming_migration(const char *path, Error **errp);
 237
 238 void fd_start_outgoing_migration(MigrationState *s, const char *fdname, Error **errp);
 239
 240 void rdma_start_outgoing_migration(void *opaque, const char *host_port, Error **errp);
 241
 242 void rdma_start_incoming_migration(const char *host_port, Error **errp);
 243
 244 void migrate_fd_error(MigrationState *s, const Error *error);
 245
 246 void migrate_fd_connect(MigrationState *s);
 247
 248 void add_migration_state_change_notifier(Notifier *notify);
 249 void remove_migration_state_change_notifier(Notifier *notify);
 250 MigrationState *migrate_init(const MigrationParams *params);
 251 bool migration_is_blocked(Error **errp);
 252 bool migration_in_setup(MigrationState *);
 253 bool migration_is_idle(MigrationState *s);
 254 bool migration_has_finished(MigrationState *);
 255 bool migration_has_failed(MigrationState *);
 256 /* True if outgoing migration has entered postcopy phase */
 257 bool migration_in_postcopy(MigrationState *);
 258 /* ...and after the device transmission */
 259 bool migration_in_postcopy_after_devices(MigrationState *);
 260 MigrationState *migrate_get_current(void);
 261
 262 void migrate_compress_threads_create(void);
 263 void migrate_compress_threads_join(void);
 264 void migrate_decompress_threads_create(void);
 265 void migrate_decompress_threads_join(void);
 266 uint64_t ram_bytes_remaining(void);
 267 uint64_t ram_bytes_transferred(void);
 268 uint64_t ram_bytes_total(void);
 269 void free_xbzrle_decoded_buf(void);
 270
 271 void acct_update_position(QEMUFile *f, size_t size, bool zero);
 272
 273 uint64_t dup_mig_bytes_transferred(void);
 274 uint64_t dup_mig_pages_transferred(void);
 275 uint64_t skipped_mig_bytes_transferred(void);
 276 uint64_t skipped_mig_pages_transferred(void);
 277 uint64_t norm_mig_bytes_transferred(void);
 278 uint64_t norm_mig_pages_transferred(void);
 279 uint64_t xbzrle_mig_bytes_transferred(void);
 280 uint64_t xbzrle_mig_pages_transferred(void);
 281 uint64_t xbzrle_mig_pages_overflow(void);
 282 uint64_t xbzrle_mig_pages_cache_miss(void);
 283 double xbzrle_mig_cache_miss_rate(void);
 284
 285 void ram_handle_compressed(void *host, uint8_t ch, uint64_t size);
 286 void ram_debug_dump_bitmap(unsigned long *todump, bool expected);
 287 /* For outgoing discard bitmap */
 288 int ram_postcopy_send_discard_bitmap(MigrationState *ms);
 289 /* For incoming postcopy discard */
 290 int ram_discard_range(MigrationIncomingState *mis, const char *block_name,
 291                       uint64_t start, size_t length);
 292 int ram_postcopy_incoming_init(MigrationIncomingState *mis);
 293 void ram_postcopy_migrated_memory_release(MigrationState *ms);
 294
 295 /**
 296  * @migrate_add_blocker - prevent migration from proceeding
 297  *
 298  * @reason - an error to be returned whenever migration is attempted
 299  *
 300  * @errp - [out] The reason (if any) we cannot block migration right now.
 301  *
 302  * @returns - 0 on success, -EBUSY/-EACCES on failure, with errp set.
 303  */
 304 int migrate_add_blocker(Error *reason, Error **errp);
 305
 306 /**
 307  * @migrate_del_blocker - remove a blocking error from migration
 308  *
 309  * @reason - the error blocking migration
 310  */
 311 void migrate_del_blocker(Error *reason);
 312
 313 bool migrate_release_ram(void);
 314 bool migrate_postcopy_ram(void);
 315 bool migrate_zero_blocks(void);
 316
 317 bool migrate_auto_converge(void);
 318
 319 int xbzrle_encode_buffer(uint8_t *old_buf, uint8_t *new_buf, int slen,
 320                          uint8_t *dst, int dlen);
 321 int xbzrle_decode_buffer(uint8_t *src, int slen, uint8_t *dst, int dlen);
 322
 323 int migrate_use_xbzrle(void);
 324 int64_t migrate_xbzrle_cache_size(void);
 325 bool migrate_colo_enabled(void);
 326
 327 int64_t xbzrle_cache_resize(int64_t new_size);
 328
 329 bool migrate_use_compression(void);
 330 int migrate_compress_level(void);
 331 int migrate_compress_threads(void);
 332 int migrate_decompress_threads(void);
 333 bool migrate_use_events(void);
 334
 335 /* Sending on the return path - generic and then for each message type */
 336 void migrate_send_rp_message(MigrationIncomingState *mis,
 337                              enum mig_rp_message_type message_type,
 338                              uint16_t len, void *data);
 339 void migrate_send_rp_shut(MigrationIncomingState *mis,
 340                           uint32_t value);
 341 void migrate_send_rp_pong(MigrationIncomingState *mis,
 342                           uint32_t value);
 343 void migrate_send_rp_req_pages(MigrationIncomingState *mis, const char* rbname,
 344                               ram_addr_t start, size_t len);
 345
 346 void ram_control_before_iterate(QEMUFile *f, uint64_t flags);
 347 void ram_control_after_iterate(QEMUFile *f, uint64_t flags);
 348 void ram_control_load_hook(QEMUFile *f, uint64_t flags, void *data);
 349
 350 /* Whenever this is found in the data stream, the flags
 351  * will be passed to ram_control_load_hook in the incoming-migration
 352  * side. This lets before_ram_iterate/after_ram_iterate add
 353  * transport-specific sections to the RAM migration data.
 354  */
 355 #define RAM_SAVE_FLAG_HOOK     0x80
 356
 357 #define RAM_SAVE_CONTROL_NOT_SUPP -1000
 358 #define RAM_SAVE_CONTROL_DELAYED  -2000
 359
 360 size_t ram_control_save_page(QEMUFile *f, ram_addr_t block_offset,
 361                              ram_addr_t offset, size_t size,
 362                              uint64_t *bytes_sent);
 363
 364 void ram_mig_init(void);
 365 void savevm_skip_section_footers(void);
 366 void register_global_state(void);
 367 void global_state_set_optional(void);
 368 void savevm_skip_configuration(void);
 369 int global_state_store(void);
 370 void global_state_store_running(void);
 371
 372 void flush_page_queue(MigrationState *ms);
 373 int ram_save_queue_pages(MigrationState *ms, const char *rbname,
 374                          ram_addr_t start, ram_addr_t len);
 375
 376 PostcopyState postcopy_state_get(void);
 377 /* Set the state and return the old state */
 378 PostcopyState postcopy_state_set(PostcopyState new_state);
 379 #endif