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     QemuThread     fault_thread;
  93     QemuSemaphore  fault_thread_sem;
  94
  95     /* For the kernel to send us notifications */
  96     int       userfault_fd;
  97     QEMUFile *to_src_file;
  98     QemuMutex rp_mutex;    /* We send replies from multiple threads */
  99     void     *postcopy_tmp_page;
 100
 101     /* See savevm.c */
 102     LoadStateEntry_Head loadvm_handlers;
 103 };
 104
 105 MigrationIncomingState *migration_incoming_get_current(void);
 106 MigrationIncomingState *migration_incoming_state_new(QEMUFile *f);
 107 void migration_incoming_state_destroy(void);
 108
 109 /*
 110  * An outstanding page request, on the source, having been received
 111  * and queued
 112  */
 113 struct MigrationSrcPageRequest {
 114     RAMBlock *rb;
 115     hwaddr    offset;
 116     hwaddr    len;
 117
 118     QSIMPLEQ_ENTRY(MigrationSrcPageRequest) next_req;
 119 };
 120
 121 struct MigrationState
 122 {
 123     int64_t bandwidth_limit;
 124     size_t bytes_xfer;
 125     size_t xfer_limit;
 126     QemuThread thread;
 127     QEMUBH *cleanup_bh;
 128     QEMUFile *file;
 129     int parameters[MIGRATION_PARAMETER_MAX];
 130
 131     int state;
 132     MigrationParams params;
 133
 134     /* State related to return path */
 135     struct {
 136         QEMUFile     *from_dst_file;
 137         QemuThread    rp_thread;
 138         bool          error;
 139     } rp_state;
 140
 141     double mbps;
 142     int64_t total_time;
 143     int64_t downtime;
 144     int64_t expected_downtime;
 145     int64_t dirty_pages_rate;
 146     int64_t dirty_bytes_rate;
 147     bool enabled_capabilities[MIGRATION_CAPABILITY_MAX];
 148     int64_t xbzrle_cache_size;
 149     int64_t setup_time;
 150     int64_t dirty_sync_count;
 151
 152     /* Flag set once the migration has been asked to enter postcopy */
 153     bool start_postcopy;
 154
 155     /* Flag set once the migration thread is running (and needs joining) */
 156     bool migration_thread_running;
 157
 158     /* Queue of outstanding page requests from the destination */
 159     QemuMutex src_page_req_mutex;
 160     QSIMPLEQ_HEAD(src_page_requests, MigrationSrcPageRequest) src_page_requests;
 161     /* The RAMBlock used in the last src_page_request */
 162     RAMBlock *last_req_rb;
 163 };
 164
 165 void process_incoming_migration(QEMUFile *f);
 166
 167 void qemu_start_incoming_migration(const char *uri, Error **errp);
 168
 169 uint64_t migrate_max_downtime(void);
 170
 171 void exec_start_incoming_migration(const char *host_port, Error **errp);
 172
 173 void exec_start_outgoing_migration(MigrationState *s, const char *host_port, Error **errp);
 174
 175 void tcp_start_incoming_migration(const char *host_port, Error **errp);
 176
 177 void tcp_start_outgoing_migration(MigrationState *s, const char *host_port, Error **errp);
 178
 179 void unix_start_incoming_migration(const char *path, Error **errp);
 180
 181 void unix_start_outgoing_migration(MigrationState *s, const char *path, Error **errp);
 182
 183 void fd_start_incoming_migration(const char *path, Error **errp);
 184
 185 void fd_start_outgoing_migration(MigrationState *s, const char *fdname, Error **errp);
 186
 187 void rdma_start_outgoing_migration(void *opaque, const char *host_port, Error **errp);
 188
 189 void rdma_start_incoming_migration(const char *host_port, Error **errp);
 190
 191 void migrate_fd_error(MigrationState *s);
 192
 193 void migrate_fd_connect(MigrationState *s);
 194
 195 int migrate_fd_close(MigrationState *s);
 196
 197 void add_migration_state_change_notifier(Notifier *notify);
 198 void remove_migration_state_change_notifier(Notifier *notify);
 199 MigrationState *migrate_init(const MigrationParams *params);
 200 bool migration_in_setup(MigrationState *);
 201 bool migration_has_finished(MigrationState *);
 202 bool migration_has_failed(MigrationState *);
 203 /* True if outgoing migration has entered postcopy phase */
 204 bool migration_in_postcopy(MigrationState *);
 205 MigrationState *migrate_get_current(void);
 206
 207 void migrate_compress_threads_create(void);
 208 void migrate_compress_threads_join(void);
 209 void migrate_decompress_threads_create(void);
 210 void migrate_decompress_threads_join(void);
 211 uint64_t ram_bytes_remaining(void);
 212 uint64_t ram_bytes_transferred(void);
 213 uint64_t ram_bytes_total(void);
 214 void free_xbzrle_decoded_buf(void);
 215
 216 void acct_update_position(QEMUFile *f, size_t size, bool zero);
 217
 218 uint64_t dup_mig_bytes_transferred(void);
 219 uint64_t dup_mig_pages_transferred(void);
 220 uint64_t skipped_mig_bytes_transferred(void);
 221 uint64_t skipped_mig_pages_transferred(void);
 222 uint64_t norm_mig_bytes_transferred(void);
 223 uint64_t norm_mig_pages_transferred(void);
 224 uint64_t xbzrle_mig_bytes_transferred(void);
 225 uint64_t xbzrle_mig_pages_transferred(void);
 226 uint64_t xbzrle_mig_pages_overflow(void);
 227 uint64_t xbzrle_mig_pages_cache_miss(void);
 228 double xbzrle_mig_cache_miss_rate(void);
 229
 230 void ram_handle_compressed(void *host, uint8_t ch, uint64_t size);
 231 void ram_debug_dump_bitmap(unsigned long *todump, bool expected);
 232 /* For outgoing discard bitmap */
 233 int ram_postcopy_send_discard_bitmap(MigrationState *ms);
 234 /* For incoming postcopy discard */
 235 int ram_discard_range(MigrationIncomingState *mis, const char *block_name,
 236                       uint64_t start, size_t length);
 237 int ram_postcopy_incoming_init(MigrationIncomingState *mis);
 238
 239 /**
 240  * @migrate_add_blocker - prevent migration from proceeding
 241  *
 242  * @reason - an error to be returned whenever migration is attempted
 243  */
 244 void migrate_add_blocker(Error *reason);
 245
 246 /**
 247  * @migrate_del_blocker - remove a blocking error from migration
 248  *
 249  * @reason - the error blocking migration
 250  */
 251 void migrate_del_blocker(Error *reason);
 252
 253 bool migrate_postcopy_ram(void);
 254 bool migrate_zero_blocks(void);
 255
 256 bool migrate_auto_converge(void);
 257
 258 int xbzrle_encode_buffer(uint8_t *old_buf, uint8_t *new_buf, int slen,
 259                          uint8_t *dst, int dlen);
 260 int xbzrle_decode_buffer(uint8_t *src, int slen, uint8_t *dst, int dlen);
 261
 262 int migrate_use_xbzrle(void);
 263 int64_t migrate_xbzrle_cache_size(void);
 264
 265 int64_t xbzrle_cache_resize(int64_t new_size);
 266
 267 bool migrate_use_compression(void);
 268 int migrate_compress_level(void);
 269 int migrate_compress_threads(void);
 270 int migrate_decompress_threads(void);
 271 bool migrate_use_events(void);
 272
 273 /* Sending on the return path - generic and then for each message type */
 274 void migrate_send_rp_message(MigrationIncomingState *mis,
 275                              enum mig_rp_message_type message_type,
 276                              uint16_t len, void *data);
 277 void migrate_send_rp_shut(MigrationIncomingState *mis,
 278                           uint32_t value);
 279 void migrate_send_rp_pong(MigrationIncomingState *mis,
 280                           uint32_t value);
 281 void migrate_send_rp_req_pages(MigrationIncomingState *mis, const char* rbname,
 282                               ram_addr_t start, size_t len);
 283
 284 void ram_control_before_iterate(QEMUFile *f, uint64_t flags);
 285 void ram_control_after_iterate(QEMUFile *f, uint64_t flags);
 286 void ram_control_load_hook(QEMUFile *f, uint64_t flags, void *data);
 287
 288 /* Whenever this is found in the data stream, the flags
 289  * will be passed to ram_control_load_hook in the incoming-migration
 290  * side. This lets before_ram_iterate/after_ram_iterate add
 291  * transport-specific sections to the RAM migration data.
 292  */
 293 #define RAM_SAVE_FLAG_HOOK     0x80
 294
 295 #define RAM_SAVE_CONTROL_NOT_SUPP -1000
 296 #define RAM_SAVE_CONTROL_DELAYED  -2000
 297
 298 size_t ram_control_save_page(QEMUFile *f, ram_addr_t block_offset,
 299                              ram_addr_t offset, size_t size,
 300                              uint64_t *bytes_sent);
 301
 302 void ram_mig_init(void);
 303 void savevm_skip_section_footers(void);
 304 void register_global_state(void);
 305 void global_state_set_optional(void);
 306 void savevm_skip_configuration(void);
 307 int global_state_store(void);
 308 void global_state_store_running(void);
 309
 310 void flush_page_queue(MigrationState *ms);
 311 int ram_save_queue_pages(MigrationState *ms, const char *rbname,
 312                          ram_addr_t start, ram_addr_t len);
 313
 314 PostcopyState postcopy_state_get(void);
 315 /* Set the state and return the old state */
 316 PostcopyState postcopy_state_set(PostcopyState new_state);
 317 #endif