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