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 "qapi/error.h"
  22 #include "migration/vmstate.h"
  23 #include "qapi-types.h"
  24 #include "exec/cpu-common.h"
  25
  26 #define QEMU_VM_FILE_MAGIC           0x5145564d
  27 #define QEMU_VM_FILE_VERSION_COMPAT  0x00000002
  28 #define QEMU_VM_FILE_VERSION         0x00000003
  29
  30 #define QEMU_VM_EOF                  0x00
  31 #define QEMU_VM_SECTION_START        0x01
  32 #define QEMU_VM_SECTION_PART         0x02
  33 #define QEMU_VM_SECTION_END          0x03
  34 #define QEMU_VM_SECTION_FULL         0x04
  35 #define QEMU_VM_SUBSECTION           0x05
  36 #define QEMU_VM_VMDESCRIPTION        0x06
  37 #define QEMU_VM_CONFIGURATION        0x07
  38 #define QEMU_VM_COMMAND              0x08
  39 #define QEMU_VM_SECTION_FOOTER       0x7e
  40
  41 struct MigrationParams {
  42     bool blk;
  43     bool shared;
  44 };
  45
  46 /* Messages sent on the return path from destination to source */
  47 enum mig_rp_message_type {
  48     MIG_RP_MSG_INVALID = 0,  /* Must be 0 */
  49     MIG_RP_MSG_SHUT,         /* sibling will not send any more RP messages */
  50     MIG_RP_MSG_PONG,         /* Response to a PING; data (seq: be32 ) */
  51
  52     MIG_RP_MSG_REQ_PAGES_ID, /* data (start: be64, len: be32, id: string) */
  53     MIG_RP_MSG_REQ_PAGES,    /* data (start: be64, len: be32) */
  54
  55     MIG_RP_MSG_MAX
  56 };
  57
  58 typedef QLIST_HEAD(, LoadStateEntry) LoadStateEntry_Head;
  59
  60 /* The current postcopy state is read/set by postcopy_state_get/set
  61  * which update it atomically.
  62  * The state is updated as postcopy messages are received, and
  63  * in general only one thread should be writing to the state at any one
  64  * time, initially the main thread and then the listen thread;
  65  * Corner cases are where either thread finishes early and/or errors.
  66  * The state is checked as messages are received to ensure that
  67  * the source is sending us messages in the correct order.
  68  * The state is also used by the RAM reception code to know if it
  69  * has to place pages atomically, and the cleanup code at the end of
  70  * the main thread to know if it has to delay cleanup until the end
  71  * of postcopy.
  72  */
  73 typedef enum {
  74     POSTCOPY_INCOMING_NONE = 0,  /* Initial state - no postcopy */
  75     POSTCOPY_INCOMING_ADVISE,
  76     POSTCOPY_INCOMING_DISCARD,
  77     POSTCOPY_INCOMING_LISTENING,
  78     POSTCOPY_INCOMING_RUNNING,
  79     POSTCOPY_INCOMING_END
  80 } PostcopyState;
  81
  82 /* State for the incoming migration */
  83 struct MigrationIncomingState {
  84     QEMUFile *from_src_file;
  85
  86     /*
  87      * Free at the start of the main state load, set as the main thread finishes
  88      * loading state.
  89      */
  90     QemuEvent main_thread_load_event;
  91
  92     bool           have_fault_thread;
  93     QemuThread     fault_thread;
  94     QemuSemaphore  fault_thread_sem;
  95
  96     bool           have_listen_thread;
  97     QemuThread     listen_thread;
  98     QemuSemaphore  listen_thread_sem;
  99
 100     /* For the kernel to send us notifications */
 101     int       userfault_fd;
 102     /* To tell the fault_thread to quit */
 103     int       userfault_quit_fd;
 104     QEMUFile *to_src_file;
 105     QemuMutex rp_mutex;    /* We send replies from multiple threads */
 106     void     *postcopy_tmp_page;
 107
 108     /* See savevm.c */
 109     LoadStateEntry_Head loadvm_handlers;
 110 };
 111
 112 MigrationIncomingState *migration_incoming_get_current(void);
 113 MigrationIncomingState *migration_incoming_state_new(QEMUFile *f);
 114 void migration_incoming_state_destroy(void);
 115
 116 /*
 117  * An outstanding page request, on the source, having been received
 118  * and queued
 119  */
 120 struct MigrationSrcPageRequest {
 121     RAMBlock *rb;
 122     hwaddr    offset;
 123     hwaddr    len;
 124
 125     QSIMPLEQ_ENTRY(MigrationSrcPageRequest) next_req;
 126 };
 127
 128 struct MigrationState
 129 {
 130     int64_t bandwidth_limit;
 131     size_t bytes_xfer;
 132     size_t xfer_limit;
 133     QemuThread thread;
 134     QEMUBH *cleanup_bh;
 135     QEMUFile *file;
 136     int parameters[MIGRATION_PARAMETER__MAX];
 137
 138     int state;
 139     MigrationParams params;
 140
 141     /* State related to return path */
 142     struct {
 143         QEMUFile     *from_dst_file;
 144         QemuThread    rp_thread;
 145         bool          error;
 146     } rp_state;
 147
 148     double mbps;
 149     int64_t total_time;
 150     int64_t downtime;
 151     int64_t expected_downtime;
 152     int64_t dirty_pages_rate;
 153     int64_t dirty_bytes_rate;
 154     bool enabled_capabilities[MIGRATION_CAPABILITY__MAX];
 155     int64_t xbzrle_cache_size;
 156     int64_t setup_time;
 157     int64_t dirty_sync_count;
 158
 159     /* Flag set once the migration has been asked to enter postcopy */
 160     bool start_postcopy;
 161
 162     /* Flag set once the migration thread is running (and needs joining) */
 163     bool migration_thread_running;
 164
 165     /* Queue of outstanding page requests from the destination */
 166     QemuMutex src_page_req_mutex;
 167     QSIMPLEQ_HEAD(src_page_requests, MigrationSrcPageRequest) src_page_requests;
 168     /* The RAMBlock used in the last src_page_request */
 169     RAMBlock *last_req_rb;
 170 };
 171
 172 void process_incoming_migration(QEMUFile *f);
 173
 174 void qemu_start_incoming_migration(const char *uri, Error **errp);
 175
 176 uint64_t migrate_max_downtime(void);
 177
 178 void exec_start_incoming_migration(const char *host_port, Error **errp);
 179
 180 void exec_start_outgoing_migration(MigrationState *s, const char *host_port, Error **errp);
 181
 182 void tcp_start_incoming_migration(const char *host_port, Error **errp);
 183
 184 void tcp_start_outgoing_migration(MigrationState *s, const char *host_port, Error **errp);
 185
 186 void unix_start_incoming_migration(const char *path, Error **errp);
 187
 188 void unix_start_outgoing_migration(MigrationState *s, const char *path, Error **errp);
 189
 190 void fd_start_incoming_migration(const char *path, Error **errp);
 191
 192 void fd_start_outgoing_migration(MigrationState *s, const char *fdname, Error **errp);
 193
 194 void rdma_start_outgoing_migration(void *opaque, const char *host_port, Error **errp);
 195
 196 void rdma_start_incoming_migration(const char *host_port, Error **errp);
 197
 198 void migrate_fd_error(MigrationState *s);
 199
 200 void migrate_fd_connect(MigrationState *s);
 201
 202 int migrate_fd_close(MigrationState *s);
 203
 204 void add_migration_state_change_notifier(Notifier *notify);
 205 void remove_migration_state_change_notifier(Notifier *notify);
 206 MigrationState *migrate_init(const MigrationParams *params);
 207 bool migration_in_setup(MigrationState *);
 208 bool migration_has_finished(MigrationState *);
 209 bool migration_has_failed(MigrationState *);
 210 /* True if outgoing migration has entered postcopy phase */
 211 bool migration_in_postcopy(MigrationState *);
 212 MigrationState *migrate_get_current(void);
 213
 214 void migrate_compress_threads_create(void);
 215 void migrate_compress_threads_join(void);
 216 void migrate_decompress_threads_create(void);
 217 void migrate_decompress_threads_join(void);
 218 uint64_t ram_bytes_remaining(void);
 219 uint64_t ram_bytes_transferred(void);
 220 uint64_t ram_bytes_total(void);
 221 void free_xbzrle_decoded_buf(void);
 222
 223 void acct_update_position(QEMUFile *f, size_t size, bool zero);
 224
 225 uint64_t dup_mig_bytes_transferred(void);
 226 uint64_t dup_mig_pages_transferred(void);
 227 uint64_t skipped_mig_bytes_transferred(void);
 228 uint64_t skipped_mig_pages_transferred(void);
 229 uint64_t norm_mig_bytes_transferred(void);
 230 uint64_t norm_mig_pages_transferred(void);
 231 uint64_t xbzrle_mig_bytes_transferred(void);
 232 uint64_t xbzrle_mig_pages_transferred(void);
 233 uint64_t xbzrle_mig_pages_overflow(void);
 234 uint64_t xbzrle_mig_pages_cache_miss(void);
 235 double xbzrle_mig_cache_miss_rate(void);
 236
 237 void ram_handle_compressed(void *host, uint8_t ch, uint64_t size);
 238 void ram_debug_dump_bitmap(unsigned long *todump, bool expected);
 239 /* For outgoing discard bitmap */
 240 int ram_postcopy_send_discard_bitmap(MigrationState *ms);
 241 /* For incoming postcopy discard */
 242 int ram_discard_range(MigrationIncomingState *mis, const char *block_name,
 243                       uint64_t start, size_t length);
 244 int ram_postcopy_incoming_init(MigrationIncomingState *mis);
 245
 246 /**
 247  * @migrate_add_blocker - prevent migration from proceeding
 248  *
 249  * @reason - an error to be returned whenever migration is attempted
 250  */
 251 void migrate_add_blocker(Error *reason);
 252
 253 /**
 254  * @migrate_del_blocker - remove a blocking error from migration
 255  *
 256  * @reason - the error blocking migration
 257  */
 258 void migrate_del_blocker(Error *reason);
 259
 260 bool migrate_postcopy_ram(void);
 261 bool migrate_zero_blocks(void);
 262
 263 bool migrate_auto_converge(void);
 264
 265 int xbzrle_encode_buffer(uint8_t *old_buf, uint8_t *new_buf, int slen,
 266                          uint8_t *dst, int dlen);
 267 int xbzrle_decode_buffer(uint8_t *src, int slen, uint8_t *dst, int dlen);
 268
 269 int migrate_use_xbzrle(void);
 270 int64_t migrate_xbzrle_cache_size(void);
 271
 272 int64_t xbzrle_cache_resize(int64_t new_size);
 273
 274 bool migrate_use_compression(void);
 275 int migrate_compress_level(void);
 276 int migrate_compress_threads(void);
 277 int migrate_decompress_threads(void);
 278 bool migrate_use_events(void);
 279
 280 /* Sending on the return path - generic and then for each message type */
 281 void migrate_send_rp_message(MigrationIncomingState *mis,
 282                              enum mig_rp_message_type message_type,
 283                              uint16_t len, void *data);
 284 void migrate_send_rp_shut(MigrationIncomingState *mis,
 285                           uint32_t value);
 286 void migrate_send_rp_pong(MigrationIncomingState *mis,
 287                           uint32_t value);
 288 void migrate_send_rp_req_pages(MigrationIncomingState *mis, const char* rbname,
 289                               ram_addr_t start, size_t len);
 290
 291 void ram_control_before_iterate(QEMUFile *f, uint64_t flags);
 292 void ram_control_after_iterate(QEMUFile *f, uint64_t flags);
 293 void ram_control_load_hook(QEMUFile *f, uint64_t flags, void *data);
 294
 295 /* Whenever this is found in the data stream, the flags
 296  * will be passed to ram_control_load_hook in the incoming-migration
 297  * side. This lets before_ram_iterate/after_ram_iterate add
 298  * transport-specific sections to the RAM migration data.
 299  */
 300 #define RAM_SAVE_FLAG_HOOK     0x80
 301
 302 #define RAM_SAVE_CONTROL_NOT_SUPP -1000
 303 #define RAM_SAVE_CONTROL_DELAYED  -2000
 304
 305 size_t ram_control_save_page(QEMUFile *f, ram_addr_t block_offset,
 306                              ram_addr_t offset, size_t size,
 307                              uint64_t *bytes_sent);
 308
 309 void ram_mig_init(void);
 310 void savevm_skip_section_footers(void);
 311 void register_global_state(void);
 312 void global_state_set_optional(void);
 313 void savevm_skip_configuration(void);
 314 int global_state_store(void);
 315 void global_state_store_running(void);
 316
 317 void flush_page_queue(MigrationState *ms);
 318 int ram_save_queue_pages(MigrationState *ms, const char *rbname,
 319                          ram_addr_t start, ram_addr_t len);
 320
 321 PostcopyState postcopy_state_get(void);
 322 /* Set the state and return the old state */
 323 PostcopyState postcopy_state_set(PostcopyState new_state);
 324 #endif