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 "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
  40struct MigrationParams {
  41    bool blk;
  42    bool shared;
  43};
  44
  45/* Messages sent on the return path from destination to source */
  46enum 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
  57typedef 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 */
  72typedef 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 */
  82struct 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
 114MigrationIncomingState *migration_incoming_get_current(void);
 115MigrationIncomingState *migration_incoming_state_new(QEMUFile *f);
 116void migration_incoming_state_destroy(void);
 117
 118/*
 119 * An outstanding page request, on the source, having been received
 120 * and queued
 121 */
 122struct MigrationSrcPageRequest {
 123    RAMBlock *rb;
 124    hwaddr    offset;
 125    hwaddr    len;
 126
 127    QSIMPLEQ_ENTRY(MigrationSrcPageRequest) next_req;
 128};
 129
 130struct 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
 176void migrate_set_state(int *state, int old_state, int new_state);
 177
 178void process_incoming_migration(QEMUFile *f);
 179
 180void qemu_start_incoming_migration(const char *uri, Error **errp);
 181
 182uint64_t migrate_max_downtime(void);
 183
 184void exec_start_incoming_migration(const char *host_port, Error **errp);
 185
 186void exec_start_outgoing_migration(MigrationState *s, const char *host_port, Error **errp);
 187
 188void tcp_start_incoming_migration(const char *host_port, Error **errp);
 189
 190void tcp_start_outgoing_migration(MigrationState *s, const char *host_port, Error **errp);
 191
 192void unix_start_incoming_migration(const char *path, Error **errp);
 193
 194void unix_start_outgoing_migration(MigrationState *s, const char *path, Error **errp);
 195
 196void fd_start_incoming_migration(const char *path, Error **errp);
 197
 198void fd_start_outgoing_migration(MigrationState *s, const char *fdname, Error **errp);
 199
 200void rdma_start_outgoing_migration(void *opaque, const char *host_port, Error **errp);
 201
 202void rdma_start_incoming_migration(const char *host_port, Error **errp);
 203
 204void migrate_fd_error(MigrationState *s);
 205
 206void migrate_fd_connect(MigrationState *s);
 207
 208int migrate_fd_close(MigrationState *s);
 209
 210void add_migration_state_change_notifier(Notifier *notify);
 211void remove_migration_state_change_notifier(Notifier *notify);
 212MigrationState *migrate_init(const MigrationParams *params);
 213bool migration_in_setup(MigrationState *);
 214bool migration_has_finished(MigrationState *);
 215bool migration_has_failed(MigrationState *);
 216/* True if outgoing migration has entered postcopy phase */
 217bool migration_in_postcopy(MigrationState *);
 218/* ...and after the device transmission */
 219bool migration_in_postcopy_after_devices(MigrationState *);
 220MigrationState *migrate_get_current(void);
 221
 222void migrate_compress_threads_create(void);
 223void migrate_compress_threads_join(void);
 224void migrate_decompress_threads_create(void);
 225void migrate_decompress_threads_join(void);
 226uint64_t ram_bytes_remaining(void);
 227uint64_t ram_bytes_transferred(void);
 228uint64_t ram_bytes_total(void);
 229void free_xbzrle_decoded_buf(void);
 230
 231void acct_update_position(QEMUFile *f, size_t size, bool zero);
 232
 233uint64_t dup_mig_bytes_transferred(void);
 234uint64_t dup_mig_pages_transferred(void);
 235uint64_t skipped_mig_bytes_transferred(void);
 236uint64_t skipped_mig_pages_transferred(void);
 237uint64_t norm_mig_bytes_transferred(void);
 238uint64_t norm_mig_pages_transferred(void);
 239uint64_t xbzrle_mig_bytes_transferred(void);
 240uint64_t xbzrle_mig_pages_transferred(void);
 241uint64_t xbzrle_mig_pages_overflow(void);
 242uint64_t xbzrle_mig_pages_cache_miss(void);
 243double xbzrle_mig_cache_miss_rate(void);
 244
 245void ram_handle_compressed(void *host, uint8_t ch, uint64_t size);
 246void ram_debug_dump_bitmap(unsigned long *todump, bool expected);
 247/* For outgoing discard bitmap */
 248int ram_postcopy_send_discard_bitmap(MigrationState *ms);
 249/* For incoming postcopy discard */
 250int ram_discard_range(MigrationIncomingState *mis, const char *block_name,
 251                      uint64_t start, size_t length);
 252int 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 */
 259void 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 */
 266void migrate_del_blocker(Error *reason);
 267
 268bool migrate_postcopy_ram(void);
 269bool migrate_zero_blocks(void);
 270
 271bool migrate_auto_converge(void);
 272
 273int xbzrle_encode_buffer(uint8_t *old_buf, uint8_t *new_buf, int slen,
 274                         uint8_t *dst, int dlen);
 275int xbzrle_decode_buffer(uint8_t *src, int slen, uint8_t *dst, int dlen);
 276
 277int migrate_use_xbzrle(void);
 278int64_t migrate_xbzrle_cache_size(void);
 279
 280int64_t xbzrle_cache_resize(int64_t new_size);
 281
 282bool migrate_use_compression(void);
 283int migrate_compress_level(void);
 284int migrate_compress_threads(void);
 285int migrate_decompress_threads(void);
 286bool migrate_use_events(void);
 287
 288/* Sending on the return path - generic and then for each message type */
 289void migrate_send_rp_message(MigrationIncomingState *mis,
 290                             enum mig_rp_message_type message_type,
 291                             uint16_t len, void *data);
 292void migrate_send_rp_shut(MigrationIncomingState *mis,
 293                          uint32_t value);
 294void migrate_send_rp_pong(MigrationIncomingState *mis,
 295                          uint32_t value);
 296void migrate_send_rp_req_pages(MigrationIncomingState *mis, const char* rbname,
 297                              ram_addr_t start, size_t len);
 298
 299void ram_control_before_iterate(QEMUFile *f, uint64_t flags);
 300void ram_control_after_iterate(QEMUFile *f, uint64_t flags);
 301void 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
 313size_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
 317void ram_mig_init(void);
 318void savevm_skip_section_footers(void);
 319void register_global_state(void);
 320void global_state_set_optional(void);
 321void savevm_skip_configuration(void);
 322int global_state_store(void);
 323void global_state_store_running(void);
 324
 325void flush_page_queue(MigrationState *ms);
 326int ram_save_queue_pages(MigrationState *ms, const char *rbname,
 327                         ram_addr_t start, ram_addr_t len);
 328
 329PostcopyState postcopy_state_get(void);
 330/* Set the state and return the old state */
 331PostcopyState postcopy_state_set(PostcopyState new_state);
 332#endif
 333