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