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