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     bool           have_fault_thread;
  97     QemuThread     fault_thread;
  98     QemuSemaphore  fault_thread_sem;
  99
 100     bool           have_listen_thread;
 101     QemuThread     listen_thread;
 102     QemuSemaphore  listen_thread_sem;
 103
 104     /* For the kernel to send us notifications */
 105     int       userfault_fd;
 106     /* To tell the fault_thread to quit */
 107     int       userfault_quit_fd;
 108     QEMUFile *to_src_file;
 109     QemuMutex rp_mutex;    /* We send replies from multiple threads */
 110     void     *postcopy_tmp_page;
 111
 112     QEMUBH *bh;
 113
 114     int state;
 115
 116     bool have_colo_incoming_thread;
 117     QemuThread colo_incoming_thread;
 118     /* The coroutine we should enter (back) after failover */
 119     Coroutine *migration_incoming_co;
 120     QemuSemaphore colo_incoming_sem;
 121
 122     /* See savevm.c */
 123     LoadStateEntry_Head loadvm_handlers;
 124 };
 125
 126 MigrationIncomingState *migration_incoming_get_current(void);
 127 void migration_incoming_state_destroy(void);
 128
 129 /*
 130  * An outstanding page request, on the source, having been received
 131  * and queued
 132  */
 133 struct MigrationSrcPageRequest {
 134     RAMBlock *rb;
 135     hwaddr    offset;
 136     hwaddr    len;
 137
 138     QSIMPLEQ_ENTRY(MigrationSrcPageRequest) next_req;
 139 };
 140
 141 struct MigrationState
 142 {
 143     size_t bytes_xfer;
 144     size_t xfer_limit;
 145     QemuThread thread;
 146     QEMUBH *cleanup_bh;
 147     QEMUFile *to_dst_file;
 148
 149     /* New style params from 'migrate-set-parameters' */
 150     MigrationParameters parameters;
 151
 152     int state;
 153     /* Old style params from 'migrate' command */
 154     MigrationParams params;
 155
 156     /* State related to return path */
 157     struct {
 158         QEMUFile     *from_dst_file;
 159         QemuThread    rp_thread;
 160         bool          error;
 161     } rp_state;
 162
 163     double mbps;
 164     int64_t total_time;
 165     int64_t downtime;
 166     int64_t expected_downtime;
 167     int64_t dirty_pages_rate;
 168     int64_t dirty_bytes_rate;
 169     bool enabled_capabilities[MIGRATION_CAPABILITY__MAX];
 170     int64_t xbzrle_cache_size;
 171     int64_t setup_time;
 172     int64_t dirty_sync_count;
 173     /* Count of requests incoming from destination */
 174     int64_t postcopy_requests;
 175
 176     /* Flag set once the migration has been asked to enter postcopy */
 177     bool start_postcopy;
 178     /* Flag set after postcopy has sent the device state */
 179     bool postcopy_after_devices;
 180
 181     /* Flag set once the migration thread is running (and needs joining) */
 182     bool migration_thread_running;
 183
 184     /* Flag set once the migration thread called bdrv_inactivate_all */
 185     bool block_inactive;
 186
 187     /* Queue of outstanding page requests from the destination */
 188     QemuMutex src_page_req_mutex;
 189     QSIMPLEQ_HEAD(src_page_requests, MigrationSrcPageRequest) src_page_requests;
 190     /* The RAMBlock used in the last src_page_request */
 191     RAMBlock *last_req_rb;
 192     /* The semaphore is used to notify COLO thread that failover is finished */
 193     QemuSemaphore colo_exit_sem;
 194
 195     /* The semaphore is used to notify COLO thread to do checkpoint */
 196     QemuSemaphore colo_checkpoint_sem;
 197     int64_t colo_checkpoint_time;
 198     QEMUTimer *colo_delay_timer;
 199
 200     /* The last error that occurred */
 201     Error *error;
 202 };
 203
 204 void migrate_set_state(int *state, int old_state, int new_state);
 205
 206 void migration_fd_process_incoming(QEMUFile *f);
 207
 208 void qemu_start_incoming_migration(const char *uri, Error **errp);
 209
 210 void migration_channel_process_incoming(MigrationState *s,
 211                                         QIOChannel *ioc);
 212
 213 void migration_tls_channel_process_incoming(MigrationState *s,
 214                                             QIOChannel *ioc,
 215                                             Error **errp);
 216
 217 void migration_channel_connect(MigrationState *s,
 218                                QIOChannel *ioc,
 219                                const char *hostname);
 220
 221 void migration_tls_channel_connect(MigrationState *s,
 222                                    QIOChannel *ioc,
 223                                    const char *hostname,
 224                                    Error **errp);
 225
 226 uint64_t migrate_max_downtime(void);
 227
 228 void exec_start_incoming_migration(const char *host_port, Error **errp);
 229
 230 void exec_start_outgoing_migration(MigrationState *s, const char *host_port, Error **errp);
 231
 232 void tcp_start_incoming_migration(const char *host_port, Error **errp);
 233
 234 void tcp_start_outgoing_migration(MigrationState *s, const char *host_port, Error **errp);
 235
 236 void unix_start_incoming_migration(const char *path, Error **errp);
 237
 238 void unix_start_outgoing_migration(MigrationState *s, const char *path, Error **errp);
 239
 240 void fd_start_incoming_migration(const char *path, Error **errp);
 241
 242 void fd_start_outgoing_migration(MigrationState *s, const char *fdname, Error **errp);
 243
 244 void rdma_start_outgoing_migration(void *opaque, const char *host_port, Error **errp);
 245
 246 void rdma_start_incoming_migration(const char *host_port, Error **errp);
 247
 248 void migrate_fd_error(MigrationState *s, const Error *error);
 249
 250 void migrate_fd_connect(MigrationState *s);
 251
 252 void add_migration_state_change_notifier(Notifier *notify);
 253 void remove_migration_state_change_notifier(Notifier *notify);
 254 MigrationState *migrate_init(const MigrationParams *params);
 255 bool migration_is_blocked(Error **errp);
 256 bool migration_in_setup(MigrationState *);
 257 bool migration_is_idle(MigrationState *s);
 258 bool migration_has_finished(MigrationState *);
 259 bool migration_has_failed(MigrationState *);
 260 /* True if outgoing migration has entered postcopy phase */
 261 bool migration_in_postcopy(MigrationState *);
 262 /* ...and after the device transmission */
 263 bool migration_in_postcopy_after_devices(MigrationState *);
 264 MigrationState *migrate_get_current(void);
 265
 266 void migrate_compress_threads_create(void);
 267 void migrate_compress_threads_join(void);
 268 void migrate_decompress_threads_create(void);
 269 void migrate_decompress_threads_join(void);
 270 uint64_t ram_bytes_remaining(void);
 271 uint64_t ram_bytes_transferred(void);
 272 uint64_t ram_bytes_total(void);
 273 void free_xbzrle_decoded_buf(void);
 274
 275 void acct_update_position(QEMUFile *f, size_t size, bool zero);
 276
 277 uint64_t dup_mig_bytes_transferred(void);
 278 uint64_t dup_mig_pages_transferred(void);
 279 uint64_t skipped_mig_bytes_transferred(void);
 280 uint64_t skipped_mig_pages_transferred(void);
 281 uint64_t norm_mig_bytes_transferred(void);
 282 uint64_t norm_mig_pages_transferred(void);
 283 uint64_t xbzrle_mig_bytes_transferred(void);
 284 uint64_t xbzrle_mig_pages_transferred(void);
 285 uint64_t xbzrle_mig_pages_overflow(void);
 286 uint64_t xbzrle_mig_pages_cache_miss(void);
 287 double xbzrle_mig_cache_miss_rate(void);
 288
 289 void ram_handle_compressed(void *host, uint8_t ch, uint64_t size);
 290 void ram_debug_dump_bitmap(unsigned long *todump, bool expected);
 291 /* For outgoing discard bitmap */
 292 int ram_postcopy_send_discard_bitmap(MigrationState *ms);
 293 /* For incoming postcopy discard */
 294 int ram_discard_range(MigrationIncomingState *mis, const char *block_name,
 295                       uint64_t start, size_t length);
 296 int ram_postcopy_incoming_init(MigrationIncomingState *mis);
 297 void ram_postcopy_migrated_memory_release(MigrationState *ms);
 298
 299 /**
 300  * @migrate_add_blocker - prevent migration from proceeding
 301  *
 302  * @reason - an error to be returned whenever migration is attempted
 303  *
 304  * @errp - [out] The reason (if any) we cannot block migration right now.
 305  *
 306  * @returns - 0 on success, -EBUSY/-EACCES on failure, with errp set.
 307  */
 308 int migrate_add_blocker(Error *reason, Error **errp);
 309
 310 /**
 311  * @migrate_del_blocker - remove a blocking error from migration
 312  *
 313  * @reason - the error blocking migration
 314  */
 315 void migrate_del_blocker(Error *reason);
 316
 317 int check_migratable(Object *obj, Error **err);
 318
 319 bool migrate_release_ram(void);
 320 bool migrate_postcopy_ram(void);
 321 bool migrate_zero_blocks(void);
 322
 323 bool migrate_auto_converge(void);
 324
 325 int xbzrle_encode_buffer(uint8_t *old_buf, uint8_t *new_buf, int slen,
 326                          uint8_t *dst, int dlen);
 327 int xbzrle_decode_buffer(uint8_t *src, int slen, uint8_t *dst, int dlen);
 328
 329 int migrate_use_xbzrle(void);
 330 int64_t migrate_xbzrle_cache_size(void);
 331 bool migrate_colo_enabled(void);
 332
 333 int64_t xbzrle_cache_resize(int64_t new_size);
 334
 335 bool migrate_use_compression(void);
 336 int migrate_compress_level(void);
 337 int migrate_compress_threads(void);
 338 int migrate_decompress_threads(void);
 339 bool migrate_use_events(void);
 340
 341 /* Sending on the return path - generic and then for each message type */
 342 void migrate_send_rp_message(MigrationIncomingState *mis,
 343                              enum mig_rp_message_type message_type,
 344                              uint16_t len, void *data);
 345 void migrate_send_rp_shut(MigrationIncomingState *mis,
 346                           uint32_t value);
 347 void migrate_send_rp_pong(MigrationIncomingState *mis,
 348                           uint32_t value);
 349 void migrate_send_rp_req_pages(MigrationIncomingState *mis, const char* rbname,
 350                               ram_addr_t start, size_t len);
 351
 352 void ram_control_before_iterate(QEMUFile *f, uint64_t flags);
 353 void ram_control_after_iterate(QEMUFile *f, uint64_t flags);
 354 void ram_control_load_hook(QEMUFile *f, uint64_t flags, void *data);
 355
 356 /* Whenever this is found in the data stream, the flags
 357  * will be passed to ram_control_load_hook in the incoming-migration
 358  * side. This lets before_ram_iterate/after_ram_iterate add
 359  * transport-specific sections to the RAM migration data.
 360  */
 361 #define RAM_SAVE_FLAG_HOOK     0x80
 362
 363 #define RAM_SAVE_CONTROL_NOT_SUPP -1000
 364 #define RAM_SAVE_CONTROL_DELAYED  -2000
 365
 366 size_t ram_control_save_page(QEMUFile *f, ram_addr_t block_offset,
 367                              ram_addr_t offset, size_t size,
 368                              uint64_t *bytes_sent);
 369
 370 void ram_mig_init(void);
 371 void savevm_skip_section_footers(void);
 372 void register_global_state(void);
 373 void global_state_set_optional(void);
 374 void savevm_skip_configuration(void);
 375 int global_state_store(void);
 376 void global_state_store_running(void);
 377
 378 void flush_page_queue(MigrationState *ms);
 379 int ram_save_queue_pages(MigrationState *ms, const char *rbname,
 380                          ram_addr_t start, ram_addr_t len);
 381 uint64_t ram_pagesize_summary(void);
 382
 383 PostcopyState postcopy_state_get(void);
 384 /* Set the state and return the old state */
 385 PostcopyState postcopy_state_set(PostcopyState new_state);
 386 #endif