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 "exec/cpu-common.h"
  18 #include "hw/qdev-core.h"
  19 #include "qapi/qapi-types-migration.h"
  20 #include "qemu/thread.h"
  21 #include "qemu/coroutine_int.h"
  22 #include "io/channel.h"
  23 #include "io/channel-buffer.h"
  24 #include "net/announce.h"
  25 #include "qom/object.h"
  26
  27 struct PostcopyBlocktimeContext;
  28
  29 #define  MIGRATION_RESUME_ACK_VALUE  (1)
  30
  31 /*
  32  * 1<<6=64 pages -> 256K chunk when page size is 4K.  This gives us
  33  * the benefit that all the chunks are 64 pages aligned then the
  34  * bitmaps are always aligned to LONG.
  35  */
  36 #define CLEAR_BITMAP_SHIFT_MIN             6
  37 /*
  38  * 1<<18=256K pages -> 1G chunk when page size is 4K.  This is the
  39  * default value to use if no one specified.
  40  */
  41 #define CLEAR_BITMAP_SHIFT_DEFAULT        18
  42 /*
  43  * 1<<31=2G pages -> 8T chunk when page size is 4K.  This should be
  44  * big enough and make sure we won't overflow easily.
  45  */
  46 #define CLEAR_BITMAP_SHIFT_MAX            31
  47
  48 /* State for the incoming migration */
  49 struct MigrationIncomingState {
  50     QEMUFile *from_src_file;
  51
  52     /* A hook to allow cleanup at the end of incoming migration */
  53     void *transport_data;
  54     void (*transport_cleanup)(void *data);
  55
  56     /*
  57      * Free at the start of the main state load, set as the main thread finishes
  58      * loading state.
  59      */
  60     QemuEvent main_thread_load_event;
  61
  62     /* For network announces */
  63     AnnounceTimer  announce_timer;
  64
  65     size_t         largest_page_size;
  66     bool           have_fault_thread;
  67     QemuThread     fault_thread;
  68     QemuSemaphore  fault_thread_sem;
  69     /* Set this when we want the fault thread to quit */
  70     bool           fault_thread_quit;
  71
  72     bool           have_listen_thread;
  73     QemuThread     listen_thread;
  74     QemuSemaphore  listen_thread_sem;
  75
  76     /* For the kernel to send us notifications */
  77     int       userfault_fd;
  78     /* To notify the fault_thread to wake, e.g., when need to quit */
  79     int       userfault_event_fd;
  80     QEMUFile *to_src_file;
  81     QemuMutex rp_mutex;    /* We send replies from multiple threads */
  82     /* RAMBlock of last request sent to source */
  83     RAMBlock *last_rb;
  84     void     *postcopy_tmp_page;
  85     void     *postcopy_tmp_zero_page;
  86     /* PostCopyFD's for external userfaultfds & handlers of shared memory */
  87     GArray   *postcopy_remote_fds;
  88
  89     QEMUBH *bh;
  90
  91     int state;
  92
  93     bool have_colo_incoming_thread;
  94     QemuThread colo_incoming_thread;
  95     /* The coroutine we should enter (back) after failover */
  96     Coroutine *migration_incoming_co;
  97     QemuSemaphore colo_incoming_sem;
  98
  99     /*
 100      * PostcopyBlocktimeContext to keep information for postcopy
 101      * live migration, to calculate vCPU block time
 102      * */
 103     struct PostcopyBlocktimeContext *blocktime_ctx;
 104
 105     /* notify PAUSED postcopy incoming migrations to try to continue */
 106     bool postcopy_recover_triggered;
 107     QemuSemaphore postcopy_pause_sem_dst;
 108     QemuSemaphore postcopy_pause_sem_fault;
 109
 110     /* List of listening socket addresses  */
 111     SocketAddressList *socket_address_list;
 112
 113     /* A tree of pages that we requested to the source VM */
 114     GTree *page_requested;
 115     /* For debugging purpose only, but would be nice to keep */
 116     int page_requested_count;
 117     /*
 118      * The mutex helps to maintain the requested pages that we sent to the
 119      * source, IOW, to guarantee coherent between the page_requests tree and
 120      * the per-ramblock receivedmap.  Note! This does not guarantee consistency
 121      * of the real page copy procedures (using UFFDIO_[ZERO]COPY).  E.g., even
 122      * if one bit in receivedmap is cleared, UFFDIO_COPY could have happened
 123      * for that page already.  This is intended so that the mutex won't
 124      * serialize and blocked by slow operations like UFFDIO_* ioctls.  However
 125      * this should be enough to make sure the page_requested tree always
 126      * contains valid information.
 127      */
 128     QemuMutex page_request_mutex;
 129 };
 130
 131 MigrationIncomingState *migration_incoming_get_current(void);
 132 void migration_incoming_state_destroy(void);
 133 /*
 134  * Functions to work with blocktime context
 135  */
 136 void fill_destination_postcopy_migration_info(MigrationInfo *info);
 137
 138 #define TYPE_MIGRATION "migration"
 139
 140 typedef struct MigrationClass MigrationClass;
 141 DECLARE_OBJ_CHECKERS(MigrationState, MigrationClass,
 142                      MIGRATION_OBJ, TYPE_MIGRATION)
 143
 144 struct MigrationClass {
 145     /*< private >*/
 146     DeviceClass parent_class;
 147 };
 148
 149 struct MigrationState {
 150     /*< private >*/
 151     DeviceState parent_obj;
 152
 153     /*< public >*/
 154     QemuThread thread;
 155     QEMUBH *vm_start_bh;
 156     QEMUBH *cleanup_bh;
 157     /* Protected by qemu_file_lock */
 158     QEMUFile *to_dst_file;
 159     QIOChannelBuffer *bioc;
 160     /*
 161      * Protects to_dst_file/from_dst_file pointers.  We need to make sure we
 162      * won't yield or hang during the critical section, since this lock will be
 163      * used in OOB command handler.
 164      */
 165     QemuMutex qemu_file_lock;
 166
 167     /*
 168      * Used to allow urgent requests to override rate limiting.
 169      */
 170     QemuSemaphore rate_limit_sem;
 171
 172     /* pages already send at the beginning of current iteration */
 173     uint64_t iteration_initial_pages;
 174
 175     /* pages transferred per second */
 176     double pages_per_second;
 177
 178     /* bytes already send at the beginning of current iteration */
 179     uint64_t iteration_initial_bytes;
 180     /* time at the start of current iteration */
 181     int64_t iteration_start_time;
 182     /*
 183      * The final stage happens when the remaining data is smaller than
 184      * this threshold; it's calculated from the requested downtime and
 185      * measured bandwidth
 186      */
 187     int64_t threshold_size;
 188
 189     /* params from 'migrate-set-parameters' */
 190     MigrationParameters parameters;
 191
 192     int state;
 193
 194     /* State related to return path */
 195     struct {
 196         /* Protected by qemu_file_lock */
 197         QEMUFile     *from_dst_file;
 198         QemuThread    rp_thread;
 199         bool          error;
 200         /*
 201          * We can also check non-zero of rp_thread, but there's no "official"
 202          * way to do this, so this bool makes it slightly more elegant.
 203          * Checking from_dst_file for this is racy because from_dst_file will
 204          * be cleared in the rp_thread!
 205          */
 206         bool          rp_thread_created;
 207         QemuSemaphore rp_sem;
 208     } rp_state;
 209
 210     double mbps;
 211     /* Timestamp when recent migration starts (ms) */
 212     int64_t start_time;
 213     /* Total time used by latest migration (ms) */
 214     int64_t total_time;
 215     /* Timestamp when VM is down (ms) to migrate the last stuff */
 216     int64_t downtime_start;
 217     int64_t downtime;
 218     int64_t expected_downtime;
 219     bool enabled_capabilities[MIGRATION_CAPABILITY__MAX];
 220     int64_t setup_time;
 221     /*
 222      * Whether guest was running when we enter the completion stage.
 223      * If migration is interrupted by any reason, we need to continue
 224      * running the guest on source.
 225      */
 226     bool vm_was_running;
 227
 228     /* Flag set once the migration has been asked to enter postcopy */
 229     bool start_postcopy;
 230     /* Flag set after postcopy has sent the device state */
 231     bool postcopy_after_devices;
 232
 233     /* Flag set once the migration thread is running (and needs joining) */
 234     bool migration_thread_running;
 235
 236     /* Flag set once the migration thread called bdrv_inactivate_all */
 237     bool block_inactive;
 238
 239     /* Migration is waiting for guest to unplug device */
 240     QemuSemaphore wait_unplug_sem;
 241
 242     /* Migration is paused due to pause-before-switchover */
 243     QemuSemaphore pause_sem;
 244
 245     /* The semaphore is used to notify COLO thread that failover is finished */
 246     QemuSemaphore colo_exit_sem;
 247
 248     /* The event is used to notify COLO thread to do checkpoint */
 249     QemuEvent colo_checkpoint_event;
 250     int64_t colo_checkpoint_time;
 251     QEMUTimer *colo_delay_timer;
 252
 253     /* The first error that has occurred.
 254        We used the mutex to be able to return the 1st error message */
 255     Error *error;
 256     /* mutex to protect errp */
 257     QemuMutex error_mutex;
 258
 259     /* Do we have to clean up -b/-i from old migrate parameters */
 260     /* This feature is deprecated and will be removed */
 261     bool must_remove_block_options;
 262
 263     /*
 264      * Global switch on whether we need to store the global state
 265      * during migration.
 266      */
 267     bool store_global_state;
 268
 269     /* Whether we send QEMU_VM_CONFIGURATION during migration */
 270     bool send_configuration;
 271     /* Whether we send section footer during migration */
 272     bool send_section_footer;
 273
 274     /* Needed by postcopy-pause state */
 275     QemuSemaphore postcopy_pause_sem;
 276     QemuSemaphore postcopy_pause_rp_sem;
 277     /*
 278      * Whether we abort the migration if decompression errors are
 279      * detected at the destination. It is left at false for qemu
 280      * older than 3.0, since only newer qemu sends streams that
 281      * do not trigger spurious decompression errors.
 282      */
 283     bool decompress_error_check;
 284
 285     /*
 286      * This decides the size of guest memory chunk that will be used
 287      * to track dirty bitmap clearing.  The size of memory chunk will
 288      * be GUEST_PAGE_SIZE << N.  Say, N=0 means we will clear dirty
 289      * bitmap for each page to send (1<<0=1); N=10 means we will clear
 290      * dirty bitmap only once for 1<<10=1K continuous guest pages
 291      * (which is in 4M chunk).
 292      */
 293     uint8_t clear_bitmap_shift;
 294
 295     /*
 296      * This save hostname when out-going migration starts
 297      */
 298     char *hostname;
 299 };
 300
 301 void migrate_set_state(int *state, int old_state, int new_state);
 302
 303 void migration_fd_process_incoming(QEMUFile *f, Error **errp);
 304 void migration_ioc_process_incoming(QIOChannel *ioc, Error **errp);
 305 void migration_incoming_process(void);
 306
 307 bool  migration_has_all_channels(void);
 308
 309 uint64_t migrate_max_downtime(void);
 310
 311 void migrate_set_error(MigrationState *s, const Error *error);
 312 void migrate_fd_error(MigrationState *s, const Error *error);
 313
 314 void migrate_fd_connect(MigrationState *s, Error *error_in);
 315
 316 bool migration_is_setup_or_active(int state);
 317 bool migration_is_running(int state);
 318
 319 void migrate_init(MigrationState *s);
 320 bool migration_is_blocked(Error **errp);
 321 /* True if outgoing migration has entered postcopy phase */
 322 bool migration_in_postcopy(void);
 323 MigrationState *migrate_get_current(void);
 324
 325 bool migrate_postcopy(void);
 326
 327 bool migrate_release_ram(void);
 328 bool migrate_postcopy_ram(void);
 329 bool migrate_zero_blocks(void);
 330 bool migrate_dirty_bitmaps(void);
 331 bool migrate_ignore_shared(void);
 332 bool migrate_validate_uuid(void);
 333
 334 bool migrate_auto_converge(void);
 335 bool migrate_use_multifd(void);
 336 bool migrate_pause_before_switchover(void);
 337 int migrate_multifd_channels(void);
 338 MultiFDCompression migrate_multifd_compression(void);
 339 int migrate_multifd_zlib_level(void);
 340 int migrate_multifd_zstd_level(void);
 341
 342 int migrate_use_xbzrle(void);
 343 uint64_t migrate_xbzrle_cache_size(void);
 344 bool migrate_colo_enabled(void);
 345
 346 bool migrate_use_block(void);
 347 bool migrate_use_block_incremental(void);
 348 int migrate_max_cpu_throttle(void);
 349 bool migrate_use_return_path(void);
 350
 351 uint64_t ram_get_total_transferred_pages(void);
 352
 353 bool migrate_use_compression(void);
 354 int migrate_compress_level(void);
 355 int migrate_compress_threads(void);
 356 int migrate_compress_wait_thread(void);
 357 int migrate_decompress_threads(void);
 358 bool migrate_use_events(void);
 359 bool migrate_postcopy_blocktime(void);
 360 bool migrate_background_snapshot(void);
 361
 362 /* Sending on the return path - generic and then for each message type */
 363 void migrate_send_rp_shut(MigrationIncomingState *mis,
 364                           uint32_t value);
 365 void migrate_send_rp_pong(MigrationIncomingState *mis,
 366                           uint32_t value);
 367 int migrate_send_rp_req_pages(MigrationIncomingState *mis, RAMBlock *rb,
 368                               ram_addr_t start, uint64_t haddr);
 369 int migrate_send_rp_message_req_pages(MigrationIncomingState *mis,
 370                                       RAMBlock *rb, ram_addr_t start);
 371 void migrate_send_rp_recv_bitmap(MigrationIncomingState *mis,
 372                                  char *block_name);
 373 void migrate_send_rp_resume_ack(MigrationIncomingState *mis, uint32_t value);
 374
 375 void dirty_bitmap_mig_before_vm_start(void);
 376 void dirty_bitmap_mig_cancel_outgoing(void);
 377 void dirty_bitmap_mig_cancel_incoming(void);
 378 bool check_dirty_bitmap_mig_alias_map(const BitmapMigrationNodeAliasList *bbm,
 379                                       Error **errp);
 380
 381 void migrate_add_address(SocketAddress *address);
 382
 383 int foreach_not_ignored_block(RAMBlockIterFunc func, void *opaque);
 384
 385 #define qemu_ram_foreach_block \
 386   #warning "Use foreach_not_ignored_block in migration code"
 387
 388 void migration_make_urgent_request(void);
 389 void migration_consume_urgent_request(void);
 390 bool migration_rate_limit(void);
 391 void migration_cancel(void);
 392
 393 void populate_vfio_info(MigrationInfo *info);
 394
 395 #endif