LXR 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 "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
  41struct MigrationParams {
  42    bool blk;
  43    bool shared;
  44};
  45
  46/* Messages sent on the return path from destination to source */
  47enum 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
  58typedef 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 */
  73typedef 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 */
  83struct 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
 112MigrationIncomingState *migration_incoming_get_current(void);
 113MigrationIncomingState *migration_incoming_state_new(QEMUFile *f);
 114void migration_incoming_state_destroy(void);
 115
 116/*
 117 * An outstanding page request, on the source, having been received
 118 * and queued
 119 */
 120struct MigrationSrcPageRequest {
 121    RAMBlock *rb;
 122    hwaddr    offset;
 123    hwaddr    len;
 124
 125    QSIMPLEQ_ENTRY(MigrationSrcPageRequest) next_req;
 126};
 127
 128struct 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
 172void process_incoming_migration(QEMUFile *f);
 173
 174void qemu_start_incoming_migration(const char *uri, Error **errp);
 175
 176uint64_t migrate_max_downtime(void);
 177
 178void exec_start_incoming_migration(const char *host_port, Error **errp);
 179
 180void exec_start_outgoing_migration(MigrationState *s, const char *host_port, Error **errp);
 181
 182void tcp_start_incoming_migration(const char *host_port, Error **errp);
 183
 184void tcp_start_outgoing_migration(MigrationState *s, const char *host_port, Error **errp);
 185
 186void unix_start_incoming_migration(const char *path, Error **errp);
 187
 188void unix_start_outgoing_migration(MigrationState *s, const char *path, Error **errp);
 189
 190void fd_start_incoming_migration(const char *path, Error **errp);
 191
 192void fd_start_outgoing_migration(MigrationState *s, const char *fdname, Error **errp);
 193
 194void rdma_start_outgoing_migration(void *opaque, const char *host_port, Error **errp);
 195
 196void rdma_start_incoming_migration(const char *host_port, Error **errp);
 197
 198void migrate_fd_error(MigrationState *s);
 199
 200void migrate_fd_connect(MigrationState *s);
 201
 202int migrate_fd_close(MigrationState *s);
 203
 204void add_migration_state_change_notifier(Notifier *notify);
 205void remove_migration_state_change_notifier(Notifier *notify);
 206MigrationState *migrate_init(const MigrationParams *params);
 207bool migration_in_setup(MigrationState *);
 208bool migration_has_finished(MigrationState *);
 209bool migration_has_failed(MigrationState *);
 210/* True if outgoing migration has entered postcopy phase */
 211bool migration_in_postcopy(MigrationState *);
 212MigrationState *migrate_get_current(void);
 213
 214void migrate_compress_threads_create(void);
 215void migrate_compress_threads_join(void);
 216void migrate_decompress_threads_create(void);
 217void migrate_decompress_threads_join(void);
 218uint64_t ram_bytes_remaining(void);
 219uint64_t ram_bytes_transferred(void);
 220uint64_t ram_bytes_total(void);
 221void free_xbzrle_decoded_buf(void);
 222
 223void acct_update_position(QEMUFile *f, size_t size, bool zero);
 224
 225uint64_t dup_mig_bytes_transferred(void);
 226uint64_t dup_mig_pages_transferred(void);
 227uint64_t skipped_mig_bytes_transferred(void);
 228uint64_t skipped_mig_pages_transferred(void);
 229uint64_t norm_mig_bytes_transferred(void);
 230uint64_t norm_mig_pages_transferred(void);
 231uint64_t xbzrle_mig_bytes_transferred(void);
 232uint64_t xbzrle_mig_pages_transferred(void);
 233uint64_t xbzrle_mig_pages_overflow(void);
 234uint64_t xbzrle_mig_pages_cache_miss(void);
 235double xbzrle_mig_cache_miss_rate(void);
 236
 237void ram_handle_compressed(void *host, uint8_t ch, uint64_t size);
 238void ram_debug_dump_bitmap(unsigned long *todump, bool expected);
 239/* For outgoing discard bitmap */
 240int ram_postcopy_send_discard_bitmap(MigrationState *ms);
 241/* For incoming postcopy discard */
 242int ram_discard_range(MigrationIncomingState *mis, const char *block_name,
 243                      uint64_t start, size_t length);
 244int 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 */
 251void 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 */
 258void migrate_del_blocker(Error *reason);
 259
 260bool migrate_postcopy_ram(void);
 261bool migrate_zero_blocks(void);
 262
 263bool migrate_auto_converge(void);
 264
 265int xbzrle_encode_buffer(uint8_t *old_buf, uint8_t *new_buf, int slen,
 266                         uint8_t *dst, int dlen);
 267int xbzrle_decode_buffer(uint8_t *src, int slen, uint8_t *dst, int dlen);
 268
 269int migrate_use_xbzrle(void);
 270int64_t migrate_xbzrle_cache_size(void);
 271
 272int64_t xbzrle_cache_resize(int64_t new_size);
 273
 274bool migrate_use_compression(void);
 275int migrate_compress_level(void);
 276int migrate_compress_threads(void);
 277int migrate_decompress_threads(void);
 278bool migrate_use_events(void);
 279
 280/* Sending on the return path - generic and then for each message type */
 281void migrate_send_rp_message(MigrationIncomingState *mis,
 282                             enum mig_rp_message_type message_type,
 283                             uint16_t len, void *data);
 284void migrate_send_rp_shut(MigrationIncomingState *mis,
 285                          uint32_t value);
 286void migrate_send_rp_pong(MigrationIncomingState *mis,
 287                          uint32_t value);
 288void migrate_send_rp_req_pages(MigrationIncomingState *mis, const char* rbname,
 289                              ram_addr_t start, size_t len);
 290
 291void ram_control_before_iterate(QEMUFile *f, uint64_t flags);
 292void ram_control_after_iterate(QEMUFile *f, uint64_t flags);
 293void 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
 305size_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
 309void ram_mig_init(void);
 310void savevm_skip_section_footers(void);
 311void register_global_state(void);
 312void global_state_set_optional(void);
 313void savevm_skip_configuration(void);
 314int global_state_store(void);
 315void global_state_store_running(void);
 316
 317void flush_page_queue(MigrationState *ms);
 318int ram_save_queue_pages(MigrationState *ms, const char *rbname,
 319                         ram_addr_t start, ram_addr_t len);
 320
 321PostcopyState postcopy_state_get(void);
 322/* Set the state and return the old state */
 323PostcopyState postcopy_state_set(PostcopyState new_state);
 324#endif
 325