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df4b102452
qemu/migration/migration.c
Juan Quintela df4b102452 migration: create new section to store global state 
This includes a new section that for now just stores the current qemu state.

Right now, there are only one way to control what is the state of the
target after migration.

- If you run the target qemu with -S, it would start stopped.
- If you run the target qemu without -S, it would run just after migration finishes.

The problem here is what happens if we start the target without -S and
there happens one error during migration that puts current state as
-EIO.  Migration would ends (notice that the error happend doing block
IO, network IO, i.e. nothing related with migration), and when
migration finish, we would just "continue" running on destination,
probably hanging the guest/corruption data, whatever.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2015-07-07 14:54:51 +02:00

979 lines
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/*
* QEMU live migration
*
* Copyright IBM, Corp. 2008
*
* Authors:
* Anthony Liguori <aliguori@us.ibm.com>
*
* This work is licensed under the terms of the GNU GPL, version 2. See
* the COPYING file in the top-level directory.
*
* Contributions after 2012-01-13 are licensed under the terms of the
* GNU GPL, version 2 or (at your option) any later version.
*/
#include "qemu-common.h"
#include "qemu/error-report.h"
#include "qemu/main-loop.h"
#include "migration/migration.h"
#include "migration/qemu-file.h"
#include "sysemu/sysemu.h"
#include "block/block.h"
#include "qapi/qmp/qerror.h"
#include "qemu/sockets.h"
#include "migration/block.h"
#include "qemu/thread.h"
#include "qmp-commands.h"
#include "trace.h"
#include "qapi/util.h"
#define MAX_THROTTLE (32 << 20) /* Migration speed throttling */
/* Amount of time to allocate to each "chunk" of bandwidth-throttled
* data. */
#define BUFFER_DELAY 100
#define XFER_LIMIT_RATIO (1000 / BUFFER_DELAY)
/* Default compression thread count */
#define DEFAULT_MIGRATE_COMPRESS_THREAD_COUNT 8
/* Default decompression thread count, usually decompression is at
* least 4 times as fast as compression.*/
#define DEFAULT_MIGRATE_DECOMPRESS_THREAD_COUNT 2
/*0: means nocompress, 1: best speed, ... 9: best compress ratio */
#define DEFAULT_MIGRATE_COMPRESS_LEVEL 1
/* Migration XBZRLE default cache size */
#define DEFAULT_MIGRATE_CACHE_SIZE (64 * 1024 * 1024)
static NotifierList migration_state_notifiers =
NOTIFIER_LIST_INITIALIZER(migration_state_notifiers);
static bool deferred_incoming;
/* When we add fault tolerance, we could have several
migrations at once. For now we don't need to add
dynamic creation of migration */
/* For outgoing */
MigrationState *migrate_get_current(void)
{
static MigrationState current_migration = {
.state = MIGRATION_STATUS_NONE,
.bandwidth_limit = MAX_THROTTLE,
.xbzrle_cache_size = DEFAULT_MIGRATE_CACHE_SIZE,
.mbps = -1,
.parameters[MIGRATION_PARAMETER_COMPRESS_LEVEL] =
DEFAULT_MIGRATE_COMPRESS_LEVEL,
.parameters[MIGRATION_PARAMETER_COMPRESS_THREADS] =
DEFAULT_MIGRATE_COMPRESS_THREAD_COUNT,
.parameters[MIGRATION_PARAMETER_DECOMPRESS_THREADS] =
DEFAULT_MIGRATE_DECOMPRESS_THREAD_COUNT,
};
return &current_migration;
}
/* For incoming */
static MigrationIncomingState *mis_current;
MigrationIncomingState *migration_incoming_get_current(void)
{
return mis_current;
}
MigrationIncomingState *migration_incoming_state_new(QEMUFile* f)
{
mis_current = g_malloc0(sizeof(MigrationIncomingState));
mis_current->file = f;
QLIST_INIT(&mis_current->loadvm_handlers);
return mis_current;
}
void migration_incoming_state_destroy(void)
{
loadvm_free_handlers(mis_current);
g_free(mis_current);
mis_current = NULL;
}
typedef struct {
uint32_t size;
uint8_t runstate[100];
} GlobalState;
static GlobalState global_state;
static int global_state_store(void)
{
if (!runstate_store((char *)global_state.runstate,
sizeof(global_state.runstate))) {
error_report("runstate name too big: %s", global_state.runstate);
trace_migrate_state_too_big();
return -EINVAL;
}
return 0;
}
static char *global_state_get_runstate(void)
{
return (char *)global_state.runstate;
}
static int global_state_post_load(void *opaque, int version_id)
{
GlobalState *s = opaque;
int ret = 0;
char *runstate = (char *)s->runstate;
trace_migrate_global_state_post_load(runstate);
if (strcmp(runstate, "running") != 0) {
Error *local_err = NULL;
int r = qapi_enum_parse(RunState_lookup, runstate, RUN_STATE_MAX,
-1, &local_err);
if (r == -1) {
if (local_err) {
error_report_err(local_err);
}
return -EINVAL;
}
ret = vm_stop_force_state(r);
}
return ret;
}
static void global_state_pre_save(void *opaque)
{
GlobalState *s = opaque;
trace_migrate_global_state_pre_save((char *)s->runstate);
s->size = strlen((char *)s->runstate) + 1;
}
static const VMStateDescription vmstate_globalstate = {
.name = "globalstate",
.version_id = 1,
.minimum_version_id = 1,
.post_load = global_state_post_load,
.pre_save = global_state_pre_save,
.fields = (VMStateField[]) {
VMSTATE_UINT32(size, GlobalState),
VMSTATE_BUFFER(runstate, GlobalState),
VMSTATE_END_OF_LIST()
},
};
void register_global_state(void)
{
/* We would use it independently that we receive it */
strcpy((char *)&global_state.runstate, "");
vmstate_register(NULL, 0, &vmstate_globalstate, &global_state);
}
/*
* Called on -incoming with a defer: uri.
* The migration can be started later after any parameters have been
* changed.
*/
static void deferred_incoming_migration(Error **errp)
{
if (deferred_incoming) {
error_setg(errp, "Incoming migration already deferred");
}
deferred_incoming = true;
}
void qemu_start_incoming_migration(const char *uri, Error **errp)
{
const char *p;
if (!strcmp(uri, "defer")) {
deferred_incoming_migration(errp);
} else if (strstart(uri, "tcp:", &p)) {
tcp_start_incoming_migration(p, errp);
#ifdef CONFIG_RDMA
} else if (strstart(uri, "rdma:", &p)) {
rdma_start_incoming_migration(p, errp);
#endif
#if !defined(WIN32)
} else if (strstart(uri, "exec:", &p)) {
exec_start_incoming_migration(p, errp);
} else if (strstart(uri, "unix:", &p)) {
unix_start_incoming_migration(p, errp);
} else if (strstart(uri, "fd:", &p)) {
fd_start_incoming_migration(p, errp);
#endif
} else {
error_setg(errp, "unknown migration protocol: %s", uri);
}
}
static void process_incoming_migration_co(void *opaque)
{
QEMUFile *f = opaque;
Error *local_err = NULL;
int ret;
migration_incoming_state_new(f);
ret = qemu_loadvm_state(f);
qemu_fclose(f);
free_xbzrle_decoded_buf();
migration_incoming_state_destroy();
if (ret < 0) {
error_report("load of migration failed: %s", strerror(-ret));
migrate_decompress_threads_join();
exit(EXIT_FAILURE);
}
qemu_announce_self();
/* Make sure all file formats flush their mutable metadata */
bdrv_invalidate_cache_all(&local_err);
if (local_err) {
error_report_err(local_err);
migrate_decompress_threads_join();
exit(EXIT_FAILURE);
}
/* runstate == "" means that we haven't received it through the
* wire, so we obey autostart. runstate == runing means that we
* need to run it, we need to make sure that we do it after
* everything else has finished. Every other state change is done
* at the post_load function */
if (strcmp(global_state_get_runstate(), "running") == 0) {
vm_start();
} else if (strcmp(global_state_get_runstate(), "") == 0) {
if (autostart) {
vm_start();
} else {
runstate_set(RUN_STATE_PAUSED);
}
}
migrate_decompress_threads_join();
}
void process_incoming_migration(QEMUFile *f)
{
Coroutine *co = qemu_coroutine_create(process_incoming_migration_co);
int fd = qemu_get_fd(f);
assert(fd != -1);
migrate_decompress_threads_create();
qemu_set_nonblock(fd);
qemu_coroutine_enter(co, f);
}
/* amount of nanoseconds we are willing to wait for migration to be down.
* the choice of nanoseconds is because it is the maximum resolution that
* get_clock() can achieve. It is an internal measure. All user-visible
* units must be in seconds */
static uint64_t max_downtime = 300000000;
uint64_t migrate_max_downtime(void)
{
return max_downtime;
}
MigrationCapabilityStatusList *qmp_query_migrate_capabilities(Error **errp)
{
MigrationCapabilityStatusList *head = NULL;
MigrationCapabilityStatusList *caps;
MigrationState *s = migrate_get_current();
int i;
caps = NULL; /* silence compiler warning */
for (i = 0; i < MIGRATION_CAPABILITY_MAX; i++) {
if (head == NULL) {
head = g_malloc0(sizeof(*caps));
caps = head;
} else {
caps->next = g_malloc0(sizeof(*caps));
caps = caps->next;
}
caps->value =
g_malloc(sizeof(*caps->value));
caps->value->capability = i;
caps->value->state = s->enabled_capabilities[i];
}
return head;
}
MigrationParameters *qmp_query_migrate_parameters(Error **errp)
{
MigrationParameters *params;
MigrationState *s = migrate_get_current();
params = g_malloc0(sizeof(*params));
params->compress_level = s->parameters[MIGRATION_PARAMETER_COMPRESS_LEVEL];
params->compress_threads =
s->parameters[MIGRATION_PARAMETER_COMPRESS_THREADS];
params->decompress_threads =
s->parameters[MIGRATION_PARAMETER_DECOMPRESS_THREADS];
return params;
}
static void get_xbzrle_cache_stats(MigrationInfo *info)
{
if (migrate_use_xbzrle()) {
info->has_xbzrle_cache = true;
info->xbzrle_cache = g_malloc0(sizeof(*info->xbzrle_cache));
info->xbzrle_cache->cache_size = migrate_xbzrle_cache_size();
info->xbzrle_cache->bytes = xbzrle_mig_bytes_transferred();
info->xbzrle_cache->pages = xbzrle_mig_pages_transferred();
info->xbzrle_cache->cache_miss = xbzrle_mig_pages_cache_miss();
info->xbzrle_cache->cache_miss_rate = xbzrle_mig_cache_miss_rate();
info->xbzrle_cache->overflow = xbzrle_mig_pages_overflow();
}
}
MigrationInfo *qmp_query_migrate(Error **errp)
{
MigrationInfo *info = g_malloc0(sizeof(*info));
MigrationState *s = migrate_get_current();
switch (s->state) {
case MIGRATION_STATUS_NONE:
/* no migration has happened ever */
break;
case MIGRATION_STATUS_SETUP:
info->has_status = true;
info->has_total_time = false;
break;
case MIGRATION_STATUS_ACTIVE:
case MIGRATION_STATUS_CANCELLING:
info->has_status = true;
info->has_total_time = true;
info->total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME)
- s->total_time;
info->has_expected_downtime = true;
info->expected_downtime = s->expected_downtime;
info->has_setup_time = true;
info->setup_time = s->setup_time;
info->has_ram = true;
info->ram = g_malloc0(sizeof(*info->ram));
info->ram->transferred = ram_bytes_transferred();
info->ram->remaining = ram_bytes_remaining();
info->ram->total = ram_bytes_total();
info->ram->duplicate = dup_mig_pages_transferred();
info->ram->skipped = skipped_mig_pages_transferred();
info->ram->normal = norm_mig_pages_transferred();
info->ram->normal_bytes = norm_mig_bytes_transferred();
info->ram->dirty_pages_rate = s->dirty_pages_rate;
info->ram->mbps = s->mbps;
info->ram->dirty_sync_count = s->dirty_sync_count;
if (blk_mig_active()) {
info->has_disk = true;
info->disk = g_malloc0(sizeof(*info->disk));
info->disk->transferred = blk_mig_bytes_transferred();
info->disk->remaining = blk_mig_bytes_remaining();
info->disk->total = blk_mig_bytes_total();
}
get_xbzrle_cache_stats(info);
break;
case MIGRATION_STATUS_COMPLETED:
get_xbzrle_cache_stats(info);
info->has_status = true;
info->has_total_time = true;
info->total_time = s->total_time;
info->has_downtime = true;
info->downtime = s->downtime;
info->has_setup_time = true;
info->setup_time = s->setup_time;
info->has_ram = true;
info->ram = g_malloc0(sizeof(*info->ram));
info->ram->transferred = ram_bytes_transferred();
info->ram->remaining = 0;
info->ram->total = ram_bytes_total();
info->ram->duplicate = dup_mig_pages_transferred();
info->ram->skipped = skipped_mig_pages_transferred();
info->ram->normal = norm_mig_pages_transferred();
info->ram->normal_bytes = norm_mig_bytes_transferred();
info->ram->mbps = s->mbps;
info->ram->dirty_sync_count = s->dirty_sync_count;
break;
case MIGRATION_STATUS_FAILED:
info->has_status = true;
break;
case MIGRATION_STATUS_CANCELLED:
info->has_status = true;
break;
}
info->status = s->state;
return info;
}
void qmp_migrate_set_capabilities(MigrationCapabilityStatusList *params,
Error **errp)
{
MigrationState *s = migrate_get_current();
MigrationCapabilityStatusList *cap;
if (s->state == MIGRATION_STATUS_ACTIVE ||
s->state == MIGRATION_STATUS_SETUP) {
error_setg(errp, QERR_MIGRATION_ACTIVE);
return;
}
for (cap = params; cap; cap = cap->next) {
s->enabled_capabilities[cap->value->capability] = cap->value->state;
}
}
void qmp_migrate_set_parameters(bool has_compress_level,
int64_t compress_level,
bool has_compress_threads,
int64_t compress_threads,
bool has_decompress_threads,
int64_t decompress_threads, Error **errp)
{
MigrationState *s = migrate_get_current();
if (has_compress_level && (compress_level < 0 || compress_level > 9)) {
error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "compress_level",
"is invalid, it should be in the range of 0 to 9");
return;
}
if (has_compress_threads &&
(compress_threads < 1 || compress_threads > 255)) {
error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
"compress_threads",
"is invalid, it should be in the range of 1 to 255");
return;
}
if (has_decompress_threads &&
(decompress_threads < 1 || decompress_threads > 255)) {
error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
"decompress_threads",
"is invalid, it should be in the range of 1 to 255");
return;
}
if (has_compress_level) {
s->parameters[MIGRATION_PARAMETER_COMPRESS_LEVEL] = compress_level;
}
if (has_compress_threads) {
s->parameters[MIGRATION_PARAMETER_COMPRESS_THREADS] = compress_threads;
}
if (has_decompress_threads) {
s->parameters[MIGRATION_PARAMETER_DECOMPRESS_THREADS] =
decompress_threads;
}
}
/* shared migration helpers */
static void migrate_set_state(MigrationState *s, int old_state, int new_state)
{
if (atomic_cmpxchg(&s->state, old_state, new_state) == new_state) {
trace_migrate_set_state(new_state);
}
}
static void migrate_fd_cleanup(void *opaque)
{
MigrationState *s = opaque;
qemu_bh_delete(s->cleanup_bh);
s->cleanup_bh = NULL;
if (s->file) {
trace_migrate_fd_cleanup();
qemu_mutex_unlock_iothread();
qemu_thread_join(&s->thread);
qemu_mutex_lock_iothread();
migrate_compress_threads_join();
qemu_fclose(s->file);
s->file = NULL;
}
assert(s->state != MIGRATION_STATUS_ACTIVE);
if (s->state != MIGRATION_STATUS_COMPLETED) {
qemu_savevm_state_cancel();
if (s->state == MIGRATION_STATUS_CANCELLING) {
migrate_set_state(s, MIGRATION_STATUS_CANCELLING,
MIGRATION_STATUS_CANCELLED);
}
}
notifier_list_notify(&migration_state_notifiers, s);
}
void migrate_fd_error(MigrationState *s)
{
trace_migrate_fd_error();
assert(s->file == NULL);
s->state = MIGRATION_STATUS_FAILED;
trace_migrate_set_state(MIGRATION_STATUS_FAILED);
notifier_list_notify(&migration_state_notifiers, s);
}
static void migrate_fd_cancel(MigrationState *s)
{
int old_state ;
QEMUFile *f = migrate_get_current()->file;
trace_migrate_fd_cancel();
do {
old_state = s->state;
if (old_state != MIGRATION_STATUS_SETUP &&
old_state != MIGRATION_STATUS_ACTIVE) {
break;
}
migrate_set_state(s, old_state, MIGRATION_STATUS_CANCELLING);
} while (s->state != MIGRATION_STATUS_CANCELLING);
/*
* If we're unlucky the migration code might be stuck somewhere in a
* send/write while the network has failed and is waiting to timeout;
* if we've got shutdown(2) available then we can force it to quit.
* The outgoing qemu file gets closed in migrate_fd_cleanup that is
* called in a bh, so there is no race against this cancel.
*/
if (s->state == MIGRATION_STATUS_CANCELLING && f) {
qemu_file_shutdown(f);
}
}
void add_migration_state_change_notifier(Notifier *notify)
{
notifier_list_add(&migration_state_notifiers, notify);
}
void remove_migration_state_change_notifier(Notifier *notify)
{
notifier_remove(notify);
}
bool migration_in_setup(MigrationState *s)
{
return s->state == MIGRATION_STATUS_SETUP;
}
bool migration_has_finished(MigrationState *s)
{
return s->state == MIGRATION_STATUS_COMPLETED;
}
bool migration_has_failed(MigrationState *s)
{
return (s->state == MIGRATION_STATUS_CANCELLED ||
s->state == MIGRATION_STATUS_FAILED);
}
static MigrationState *migrate_init(const MigrationParams *params)
{
MigrationState *s = migrate_get_current();
int64_t bandwidth_limit = s->bandwidth_limit;
bool enabled_capabilities[MIGRATION_CAPABILITY_MAX];
int64_t xbzrle_cache_size = s->xbzrle_cache_size;
int compress_level = s->parameters[MIGRATION_PARAMETER_COMPRESS_LEVEL];
int compress_thread_count =
s->parameters[MIGRATION_PARAMETER_COMPRESS_THREADS];
int decompress_thread_count =
s->parameters[MIGRATION_PARAMETER_DECOMPRESS_THREADS];
memcpy(enabled_capabilities, s->enabled_capabilities,
sizeof(enabled_capabilities));
memset(s, 0, sizeof(*s));
s->params = *params;
memcpy(s->enabled_capabilities, enabled_capabilities,
sizeof(enabled_capabilities));
s->xbzrle_cache_size = xbzrle_cache_size;
s->parameters[MIGRATION_PARAMETER_COMPRESS_LEVEL] = compress_level;
s->parameters[MIGRATION_PARAMETER_COMPRESS_THREADS] =
compress_thread_count;
s->parameters[MIGRATION_PARAMETER_DECOMPRESS_THREADS] =
decompress_thread_count;
s->bandwidth_limit = bandwidth_limit;
s->state = MIGRATION_STATUS_SETUP;
trace_migrate_set_state(MIGRATION_STATUS_SETUP);
s->total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
return s;
}
static GSList *migration_blockers;
void migrate_add_blocker(Error *reason)
{
migration_blockers = g_slist_prepend(migration_blockers, reason);
}
void migrate_del_blocker(Error *reason)
{
migration_blockers = g_slist_remove(migration_blockers, reason);
}
void qmp_migrate_incoming(const char *uri, Error **errp)
{
Error *local_err = NULL;
static bool once = true;
if (!deferred_incoming) {
error_setg(errp, "For use with '-incoming defer'");
return;
}
if (!once) {
error_setg(errp, "The incoming migration has already been started");
}
qemu_start_incoming_migration(uri, &local_err);
if (local_err) {
error_propagate(errp, local_err);
return;
}
once = false;
}
void qmp_migrate(const char *uri, bool has_blk, bool blk,
bool has_inc, bool inc, bool has_detach, bool detach,
Error **errp)
{
Error *local_err = NULL;
MigrationState *s = migrate_get_current();
MigrationParams params;
const char *p;
params.blk = has_blk && blk;
params.shared = has_inc && inc;
if (s->state == MIGRATION_STATUS_ACTIVE ||
s->state == MIGRATION_STATUS_SETUP ||
s->state == MIGRATION_STATUS_CANCELLING) {
error_setg(errp, QERR_MIGRATION_ACTIVE);
return;
}
if (runstate_check(RUN_STATE_INMIGRATE)) {
error_setg(errp, "Guest is waiting for an incoming migration");
return;
}
if (qemu_savevm_state_blocked(errp)) {
return;
}
if (migration_blockers) {
*errp = error_copy(migration_blockers->data);
return;
}
s = migrate_init(&params);
if (strstart(uri, "tcp:", &p)) {
tcp_start_outgoing_migration(s, p, &local_err);
#ifdef CONFIG_RDMA
} else if (strstart(uri, "rdma:", &p)) {
rdma_start_outgoing_migration(s, p, &local_err);
#endif
#if !defined(WIN32)
} else if (strstart(uri, "exec:", &p)) {
exec_start_outgoing_migration(s, p, &local_err);
} else if (strstart(uri, "unix:", &p)) {
unix_start_outgoing_migration(s, p, &local_err);
} else if (strstart(uri, "fd:", &p)) {
fd_start_outgoing_migration(s, p, &local_err);
#endif
} else {
error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "uri",
"a valid migration protocol");
s->state = MIGRATION_STATUS_FAILED;
return;
}
if (local_err) {
migrate_fd_error(s);
error_propagate(errp, local_err);
return;
}
}
void qmp_migrate_cancel(Error **errp)
{
migrate_fd_cancel(migrate_get_current());
}
void qmp_migrate_set_cache_size(int64_t value, Error **errp)
{
MigrationState *s = migrate_get_current();
int64_t new_size;
/* Check for truncation */
if (value != (size_t)value) {
error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "cache size",
"exceeding address space");
return;
}
/* Cache should not be larger than guest ram size */
if (value > ram_bytes_total()) {
error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "cache size",
"exceeds guest ram size ");
return;
}
new_size = xbzrle_cache_resize(value);
if (new_size < 0) {
error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "cache size",
"is smaller than page size");
return;
}
s->xbzrle_cache_size = new_size;
}
int64_t qmp_query_migrate_cache_size(Error **errp)
{
return migrate_xbzrle_cache_size();
}
void qmp_migrate_set_speed(int64_t value, Error **errp)
{
MigrationState *s;
if (value < 0) {
value = 0;
}
if (value > SIZE_MAX) {
value = SIZE_MAX;
}
s = migrate_get_current();
s->bandwidth_limit = value;
if (s->file) {
qemu_file_set_rate_limit(s->file, s->bandwidth_limit / XFER_LIMIT_RATIO);
}
}
void qmp_migrate_set_downtime(double value, Error **errp)
{
value *= 1e9;
value = MAX(0, MIN(UINT64_MAX, value));
max_downtime = (uint64_t)value;
}
bool migrate_auto_converge(void)
{
MigrationState *s;
s = migrate_get_current();
return s->enabled_capabilities[MIGRATION_CAPABILITY_AUTO_CONVERGE];
}
bool migrate_zero_blocks(void)
{
MigrationState *s;
s = migrate_get_current();
return s->enabled_capabilities[MIGRATION_CAPABILITY_ZERO_BLOCKS];
}
bool migrate_use_compression(void)
{
MigrationState *s;
s = migrate_get_current();
return s->enabled_capabilities[MIGRATION_CAPABILITY_COMPRESS];
}
int migrate_compress_level(void)
{
MigrationState *s;
s = migrate_get_current();
return s->parameters[MIGRATION_PARAMETER_COMPRESS_LEVEL];
}
int migrate_compress_threads(void)
{
MigrationState *s;
s = migrate_get_current();
return s->parameters[MIGRATION_PARAMETER_COMPRESS_THREADS];
}
int migrate_decompress_threads(void)
{
MigrationState *s;
s = migrate_get_current();
return s->parameters[MIGRATION_PARAMETER_DECOMPRESS_THREADS];
}
int migrate_use_xbzrle(void)
{
MigrationState *s;
s = migrate_get_current();
return s->enabled_capabilities[MIGRATION_CAPABILITY_XBZRLE];
}
int64_t migrate_xbzrle_cache_size(void)
{
MigrationState *s;
s = migrate_get_current();
return s->xbzrle_cache_size;
}
/* migration thread support */
static void *migration_thread(void *opaque)
{
MigrationState *s = opaque;
int64_t initial_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
int64_t setup_start = qemu_clock_get_ms(QEMU_CLOCK_HOST);
int64_t initial_bytes = 0;
int64_t max_size = 0;
int64_t start_time = initial_time;
bool old_vm_running = false;
qemu_savevm_state_header(s->file);
qemu_savevm_state_begin(s->file, &s->params);
s->setup_time = qemu_clock_get_ms(QEMU_CLOCK_HOST) - setup_start;
migrate_set_state(s, MIGRATION_STATUS_SETUP, MIGRATION_STATUS_ACTIVE);
while (s->state == MIGRATION_STATUS_ACTIVE) {
int64_t current_time;
uint64_t pending_size;
if (!qemu_file_rate_limit(s->file)) {
pending_size = qemu_savevm_state_pending(s->file, max_size);
trace_migrate_pending(pending_size, max_size);
if (pending_size && pending_size >= max_size) {
qemu_savevm_state_iterate(s->file);
} else {
int ret;
qemu_mutex_lock_iothread();
start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER);
old_vm_running = runstate_is_running();
ret = global_state_store();
if (!ret) {
ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE);
if (ret >= 0) {
qemu_file_set_rate_limit(s->file, INT64_MAX);
qemu_savevm_state_complete(s->file);
}
}
qemu_mutex_unlock_iothread();
if (ret < 0) {
migrate_set_state(s, MIGRATION_STATUS_ACTIVE,
MIGRATION_STATUS_FAILED);
break;
}
if (!qemu_file_get_error(s->file)) {
migrate_set_state(s, MIGRATION_STATUS_ACTIVE,
MIGRATION_STATUS_COMPLETED);
break;
}
}
}
if (qemu_file_get_error(s->file)) {
migrate_set_state(s, MIGRATION_STATUS_ACTIVE,
MIGRATION_STATUS_FAILED);
break;
}
current_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
if (current_time >= initial_time + BUFFER_DELAY) {
uint64_t transferred_bytes = qemu_ftell(s->file) - initial_bytes;
uint64_t time_spent = current_time - initial_time;
double bandwidth = transferred_bytes / time_spent;
max_size = bandwidth * migrate_max_downtime() / 1000000;
s->mbps = time_spent ? (((double) transferred_bytes * 8.0) /
((double) time_spent / 1000.0)) / 1000.0 / 1000.0 : -1;
trace_migrate_transferred(transferred_bytes, time_spent,
bandwidth, max_size);
/* if we haven't sent anything, we don't want to recalculate
10000 is a small enough number for our purposes */
if (s->dirty_bytes_rate && transferred_bytes > 10000) {
s->expected_downtime = s->dirty_bytes_rate / bandwidth;
}
qemu_file_reset_rate_limit(s->file);
initial_time = current_time;
initial_bytes = qemu_ftell(s->file);
}
if (qemu_file_rate_limit(s->file)) {
/* usleep expects microseconds */
g_usleep((initial_time + BUFFER_DELAY - current_time)*1000);
}
}
qemu_mutex_lock_iothread();
if (s->state == MIGRATION_STATUS_COMPLETED) {
int64_t end_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
uint64_t transferred_bytes = qemu_ftell(s->file);
s->total_time = end_time - s->total_time;
s->downtime = end_time - start_time;
if (s->total_time) {
s->mbps = (((double) transferred_bytes * 8.0) /
((double) s->total_time)) / 1000;
}
runstate_set(RUN_STATE_POSTMIGRATE);
} else {
if (old_vm_running) {
vm_start();
}
}
qemu_bh_schedule(s->cleanup_bh);
qemu_mutex_unlock_iothread();
return NULL;
}
void migrate_fd_connect(MigrationState *s)
{
/* This is a best 1st approximation. ns to ms */
s->expected_downtime = max_downtime/1000000;
s->cleanup_bh = qemu_bh_new(migrate_fd_cleanup, s);
qemu_file_set_rate_limit(s->file,
s->bandwidth_limit / XFER_LIMIT_RATIO);
/* Notify before starting migration thread */
notifier_list_notify(&migration_state_notifiers, s);
migrate_compress_threads_create();
qemu_thread_create(&s->thread, "migration", migration_thread, s,
QEMU_THREAD_JOINABLE);
}
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