qemu/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
  25 #define QEMU_VM_FILE_MAGIC           0x5145564d
  26 #define QEMU_VM_FILE_VERSION_COMPAT  0x00000002
  27 #define QEMU_VM_FILE_VERSION         0x00000003
  28
  29 #define QEMU_VM_EOF                  0x00
  30 #define QEMU_VM_SECTION_START        0x01
  31 #define QEMU_VM_SECTION_PART         0x02
  32 #define QEMU_VM_SECTION_END          0x03
  33 #define QEMU_VM_SECTION_FULL         0x04
  34 #define QEMU_VM_SUBSECTION           0x05
  35 #define QEMU_VM_VMDESCRIPTION        0x06
  36 #define QEMU_VM_CONFIGURATION        0x07
  37 #define QEMU_VM_COMMAND              0x08
  38 #define QEMU_VM_SECTION_FOOTER       0x7e
  39
  40 struct MigrationParams {
  41     bool blk;
  42     bool shared;
  43 };
  44
  45 /* Messages sent on the return path from destination to source */
  46 enum mig_rp_message_type {
  47     MIG_RP_MSG_INVALID = 0,  /* Must be 0 */
  48     MIG_RP_MSG_SHUT,         /* sibling will not send any more RP messages */
  49     MIG_RP_MSG_PONG,         /* Response to a PING; data (seq: be32 ) */
  50
  51     MIG_RP_MSG_REQ_PAGES_ID, /* data (start: be64, len: be32, id: string) */
  52     MIG_RP_MSG_REQ_PAGES,    /* data (start: be64, len: be32) */
  53
  54     MIG_RP_MSG_MAX
  55 };
  56
  57 typedef QLIST_HEAD(, LoadStateEntry) LoadStateEntry_Head;
  58
  59 /* The current postcopy state is read/set by postcopy_state_get/set
  60  * which update it atomically.
  61  * The state is updated as postcopy messages are received, and
  62  * in general only one thread should be writing to the state at any one
  63  * time, initially the main thread and then the listen thread;
  64  * Corner cases are where either thread finishes early and/or errors.
  65  * The state is checked as messages are received to ensure that
  66  * the source is sending us messages in the correct order.
  67  * The state is also used by the RAM reception code to know if it
  68  * has to place pages atomically, and the cleanup code at the end of
  69  * the main thread to know if it has to delay cleanup until the end
  70  * of postcopy.
  71  */
  72 typedef enum {
  73     POSTCOPY_INCOMING_NONE = 0,  /* Initial state - no postcopy */
  74     POSTCOPY_INCOMING_ADVISE,
  75     POSTCOPY_INCOMING_DISCARD,
  76     POSTCOPY_INCOMING_LISTENING,
  77     POSTCOPY_INCOMING_RUNNING,
  78     POSTCOPY_INCOMING_END
  79 } PostcopyState;
  80
  81 /* State for the incoming migration */
  82 struct MigrationIncomingState {
  83     QEMUFile *from_src_file;
  84
  85     /*
  86      * Free at the start of the main state load, set as the main thread finishes
  87      * loading state.
  88      */
  89     QemuEvent main_thread_load_event;
  90
  91     bool           have_fault_thread;
  92     QemuThread     fault_thread;
  93     QemuSemaphore  fault_thread_sem;
  94
  95     bool           have_listen_thread;
  96     QemuThread     listen_thread;
  97     QemuSemaphore  listen_thread_sem;
  98
  99     /* For the kernel to send us notifications */
 100     int       userfault_fd;
 101     /* To tell the fault_thread to quit */
 102     int       userfault_quit_fd;
 103     QEMUFile *to_src_file;
 104     QemuMutex rp_mutex;    /* We send replies from multiple threads */
 105     void     *postcopy_tmp_page;
 106
 107     QEMUBH *bh;
 108
 109     int state;
 110     /* See savevm.c */
 111     LoadStateEntry_Head loadvm_handlers;
 112 };
 113
 114 MigrationIncomingState *migration_incoming_get_current(void);
 115 MigrationIncomingState *migration_incoming_state_new(QEMUFile *f);
 116 void migration_incoming_state_destroy(void);
 117
 118 /*
 119  * An outstanding page request, on the source, having been received
 120  * and queued
 121  */
 122 struct MigrationSrcPageRequest {
 123     RAMBlock *rb;
 124     hwaddr    offset;
 125     hwaddr    len;
 126
 127     QSIMPLEQ_ENTRY(MigrationSrcPageRequest) next_req;
 128 };
 129
 130 struct MigrationState
 131 {
 132     int64_t bandwidth_limit;
 133     size_t bytes_xfer;
 134     size_t xfer_limit;
 135     QemuThread thread;
 136     QEMUBH *cleanup_bh;
 137     QEMUFile *to_dst_file;
 138     int parameters[MIGRATION_PARAMETER__MAX];
 139
 140     int state;
 141     MigrationParams params;
 142
 143     /* State related to return path */
 144     struct {
 145         QEMUFile     *from_dst_file;
 146         QemuThread    rp_thread;
 147         bool          error;
 148     } rp_state;
 149
 150     double mbps;
 151     int64_t total_time;
 152     int64_t downtime;
 153     int64_t expected_downtime;
 154     int64_t dirty_pages_rate;
 155     int64_t dirty_bytes_rate;
 156     bool enabled_capabilities[MIGRATION_CAPABILITY__MAX];
 157     int64_t xbzrle_cache_size;
 158     int64_t setup_time;
 159     int64_t dirty_sync_count;
 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     /* Queue of outstanding page requests from the destination */
 170     QemuMutex src_page_req_mutex;
 171     QSIMPLEQ_HEAD(src_page_requests, MigrationSrcPageRequest) src_page_requests;
 172     /* The RAMBlock used in the last src_page_request */
 173     RAMBlock *last_req_rb;
 174 };
 175
 176 void migrate_set_state(int *state, int old_state, int new_state);
 177
 178 void process_incoming_migration(QEMUFile *f);
 179
 180 void qemu_start_incoming_migration(const char *uri, Error **errp);
 181
 182 uint64_t migrate_max_downtime(void);
 183
 184 void exec_start_incoming_migration(const char *host_port, Error **errp);
 185
 186 void exec_start_outgoing_migration(MigrationState *s, const char *host_port, Error **errp);
 187
 188 void tcp_start_incoming_migration(const char *host_port, Error **errp);
 189
 190 void tcp_start_outgoing_migration(MigrationState *s, const char *host_port, Error **errp);
 191
 192 void unix_start_incoming_migration(const char *path, Error **errp);
 193
 194 void unix_start_outgoing_migration(MigrationState *s, const char *path, Error **errp);
 195
 196 void fd_start_incoming_migration(const char *path, Error **errp);
 197
 198 void fd_start_outgoing_migration(MigrationState *s, const char *fdname, Error **errp);
 199
 200 void rdma_start_outgoing_migration(void *opaque, const char *host_port, Error **errp);
 201
 202 void rdma_start_incoming_migration(const char *host_port, Error **errp);
 203
 204 void migrate_fd_error(MigrationState *s);
 205
 206 void migrate_fd_connect(MigrationState *s);
 207
 208 int migrate_fd_close(MigrationState *s);
 209
 210 void add_migration_state_change_notifier(Notifier *notify);
 211 void remove_migration_state_change_notifier(Notifier *notify);
 212 MigrationState *migrate_init(const MigrationParams *params);
 213 bool migration_in_setup(MigrationState *);
 214 bool migration_has_finished(MigrationState *);
 215 bool migration_has_failed(MigrationState *);
 216 /* True if outgoing migration has entered postcopy phase */
 217 bool migration_in_postcopy(MigrationState *);
 218 /* ...and after the device transmission */
 219 bool migration_in_postcopy_after_devices(MigrationState *);
 220 MigrationState *migrate_get_current(void);
 221
 222 void migrate_compress_threads_create(void);
 223 void migrate_compress_threads_join(void);
 224 void migrate_decompress_threads_create(void);
 225 void migrate_decompress_threads_join(void);
 226 uint64_t ram_bytes_remaining(void);
 227 uint64_t ram_bytes_transferred(void);
 228 uint64_t ram_bytes_total(void);
 229 void free_xbzrle_decoded_buf(void);
 230
 231 void acct_update_position(QEMUFile *f, size_t size, bool zero);
 232
 233 uint64_t dup_mig_bytes_transferred(void);
 234 uint64_t dup_mig_pages_transferred(void);
 235 uint64_t skipped_mig_bytes_transferred(void);
 236 uint64_t skipped_mig_pages_transferred(void);
 237 uint64_t norm_mig_bytes_transferred(void);
 238 uint64_t norm_mig_pages_transferred(void);
 239 uint64_t xbzrle_mig_bytes_transferred(void);
 240 uint64_t xbzrle_mig_pages_transferred(void);
 241 uint64_t xbzrle_mig_pages_overflow(void);
 242 uint64_t xbzrle_mig_pages_cache_miss(void);
 243 double xbzrle_mig_cache_miss_rate(void);
 244
 245 void ram_handle_compressed(void *host, uint8_t ch, uint64_t size);
 246 void ram_debug_dump_bitmap(unsigned long *todump, bool expected);
 247 /* For outgoing discard bitmap */
 248 int ram_postcopy_send_discard_bitmap(MigrationState *ms);
 249 /* For incoming postcopy discard */
 250 int ram_discard_range(MigrationIncomingState *mis, const char *block_name,
 251                       uint64_t start, size_t length);
 252 int ram_postcopy_incoming_init(MigrationIncomingState *mis);
 253
 254 /**
 255  * @migrate_add_blocker - prevent migration from proceeding
 256  *
 257  * @reason - an error to be returned whenever migration is attempted
 258  */
 259 void migrate_add_blocker(Error *reason);
 260
 261 /**
 262  * @migrate_del_blocker - remove a blocking error from migration
 263  *
 264  * @reason - the error blocking migration
 265  */
 266 void migrate_del_blocker(Error *reason);
 267
 268 bool migrate_postcopy_ram(void);
 269 bool migrate_zero_blocks(void);
 270
 271 bool migrate_auto_converge(void);
 272
 273 int xbzrle_encode_buffer(uint8_t *old_buf, uint8_t *new_buf, int slen,
 274                          uint8_t *dst, int dlen);
 275 int xbzrle_decode_buffer(uint8_t *src, int slen, uint8_t *dst, int dlen);
 276
 277 int migrate_use_xbzrle(void);
 278 int64_t migrate_xbzrle_cache_size(void);
 279
 280 int64_t xbzrle_cache_resize(int64_t new_size);
 281
 282 bool migrate_use_compression(void);
 283 int migrate_compress_level(void);
 284 int migrate_compress_threads(void);
 285 int migrate_decompress_threads(void);
 286 bool migrate_use_events(void);
 287
 288 /* Sending on the return path - generic and then for each message type */
 289 void migrate_send_rp_message(MigrationIncomingState *mis,
 290                              enum mig_rp_message_type message_type,
 291                              uint16_t len, void *data);
 292 void migrate_send_rp_shut(MigrationIncomingState *mis,
 293                           uint32_t value);
 294 void migrate_send_rp_pong(MigrationIncomingState *mis,
 295                           uint32_t value);
 296 void migrate_send_rp_req_pages(MigrationIncomingState *mis, const char* rbname,
 297                               ram_addr_t start, size_t len);
 298
 299 void ram_control_before_iterate(QEMUFile *f, uint64_t flags);
 300 void ram_control_after_iterate(QEMUFile *f, uint64_t flags);
 301 void ram_control_load_hook(QEMUFile *f, uint64_t flags, void *data);
 302
 303 /* Whenever this is found in the data stream, the flags
 304  * will be passed to ram_control_load_hook in the incoming-migration
 305  * side. This lets before_ram_iterate/after_ram_iterate add
 306  * transport-specific sections to the RAM migration data.
 307  */
 308 #define RAM_SAVE_FLAG_HOOK     0x80
 309
 310 #define RAM_SAVE_CONTROL_NOT_SUPP -1000
 311 #define RAM_SAVE_CONTROL_DELAYED  -2000
 312
 313 size_t ram_control_save_page(QEMUFile *f, ram_addr_t block_offset,
 314                              ram_addr_t offset, size_t size,
 315                              uint64_t *bytes_sent);
 316
 317 void ram_mig_init(void);
 318 void savevm_skip_section_footers(void);
 319 void register_global_state(void);
 320 void global_state_set_optional(void);
 321 void savevm_skip_configuration(void);
 322 int global_state_store(void);
 323 void global_state_store_running(void);
 324
 325 void flush_page_queue(MigrationState *ms);
 326 int ram_save_queue_pages(MigrationState *ms, const char *rbname,
 327                          ram_addr_t start, ram_addr_t len);
 328
 329 PostcopyState postcopy_state_get(void);
 330 /* Set the state and return the old state */
 331 PostcopyState postcopy_state_set(PostcopyState new_state);
 332 #endif