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Tag: 20120809
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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.
*
*/
#include "qemu-common.h"
#include "migration.h"
#include "monitor.h"
#include "buffered_file.h"
#include "sysemu.h"
#include "block.h"
#include "qemu_socket.h"
#include "block-migration.h"
#include "qemu-objects.h"
//#define DEBUG_MIGRATION
#ifdef DEBUG_MIGRATION
#define DPRINTF(fmt, ...) \
do { printf("migration: " fmt, ## __VA_ARGS__); } while (0)
#else
#define DPRINTF(fmt, ...) \
do { } while (0)
#endif
/* Migration speed throttling */
static int64_t max_throttle = (32 << 20);
static MigrationState *current_migration;
static NotifierList migration_state_notifiers =
NOTIFIER_LIST_INITIALIZER(migration_state_notifiers);
int qemu_start_incoming_migration(const char *uri)
{
const char *p;
int ret;
if (strstart(uri, "tcp:", &p))
ret = tcp_start_incoming_migration(p);
#if !defined(WIN32)
else if (strstart(uri, "exec:", &p))
ret = exec_start_incoming_migration(p);
else if (strstart(uri, "unix:", &p))
ret = unix_start_incoming_migration(p);
else if (strstart(uri, "fd:", &p))
ret = fd_start_incoming_migration(p);
#endif
else {
fprintf(stderr, "unknown migration protocol: %s\n", uri);
ret = -EPROTONOSUPPORT;
}
return ret;
}
void process_incoming_migration(QEMUFile *f)
{
if (qemu_loadvm_state(f) < 0) {
fprintf(stderr, "load of migration failed\n");
exit(0);
}
qemu_announce_self();
DPRINTF("successfully loaded vm state\n");
incoming_expected = false;
if (autostart)
vm_start();
}
int do_migrate(Monitor *mon, const QDict *qdict, QObject **ret_data)
{
MigrationState *s = NULL;
const char *p;
int detach = qdict_get_try_bool(qdict, "detach", 0);
int blk = qdict_get_try_bool(qdict, "blk", 0);
int inc = qdict_get_try_bool(qdict, "inc", 0);
const char *uri = qdict_get_str(qdict, "uri");
if (current_migration &&
current_migration->get_status(current_migration) == MIG_STATE_ACTIVE) {
monitor_printf(mon, "migration already in progress\n");
return -1;
}
if (qemu_savevm_state_blocked(mon)) {
return -1;
}
if (strstart(uri, "tcp:", &p)) {
s = tcp_start_outgoing_migration(mon, p, max_throttle, detach,
blk, inc);
#if !defined(WIN32)
} else if (strstart(uri, "exec:", &p)) {
s = exec_start_outgoing_migration(mon, p, max_throttle, detach,
blk, inc);
} else if (strstart(uri, "unix:", &p)) {
s = unix_start_outgoing_migration(mon, p, max_throttle, detach,
blk, inc);
} else if (strstart(uri, "fd:", &p)) {
s = fd_start_outgoing_migration(mon, p, max_throttle, detach,
blk, inc);
#endif
} else {
monitor_printf(mon, "unknown migration protocol: %s\n", uri);
return -1;
}
if (s == NULL) {
monitor_printf(mon, "migration failed\n");
return -1;
}
if (current_migration) {
current_migration->release(current_migration);
}
current_migration = s;
notifier_list_notify(&migration_state_notifiers);
return 0;
}
int do_migrate_cancel(Monitor *mon, const QDict *qdict, QObject **ret_data)
{
MigrationState *s = current_migration;
if (s)
s->cancel(s);
return 0;
}
int do_migrate_set_speed(Monitor *mon, const QDict *qdict, QObject **ret_data)
{
int64_t d;
FdMigrationState *s;
d = qdict_get_int(qdict, "value");
if (d < 0) {
d = 0;
}
max_throttle = d;
s = migrate_to_fms(current_migration);
if (s && s->file) {
qemu_file_set_rate_limit(s->file, max_throttle);
}
return 0;
}
/* 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 = 30000000;
uint64_t migrate_max_downtime(void)
{
return max_downtime;
}
int do_migrate_set_downtime(Monitor *mon, const QDict *qdict,
QObject **ret_data)
{
double d;
d = qdict_get_double(qdict, "value") * 1e9;
d = MAX(0, MIN(UINT64_MAX, d));
max_downtime = (uint64_t)d;
return 0;
}
static void migrate_print_status(Monitor *mon, const char *name,
const QDict *status_dict)
{
QDict *qdict;
qdict = qobject_to_qdict(qdict_get(status_dict, name));
monitor_printf(mon, "transferred %s: %" PRIu64 " kbytes\n", name,
qdict_get_int(qdict, "transferred") >> 10);
monitor_printf(mon, "remaining %s: %" PRIu64 " kbytes\n", name,
qdict_get_int(qdict, "remaining") >> 10);
monitor_printf(mon, "total %s: %" PRIu64 " kbytes\n", name,
qdict_get_int(qdict, "total") >> 10);
}
void do_info_migrate_print(Monitor *mon, const QObject *data)
{
QDict *qdict;
qdict = qobject_to_qdict(data);
monitor_printf(mon, "Migration status: %s\n",
qdict_get_str(qdict, "status"));
if (qdict_haskey(qdict, "ram")) {
migrate_print_status(mon, "ram", qdict);
}
if (qdict_haskey(qdict, "disk")) {
migrate_print_status(mon, "disk", qdict);
}
}
static void migrate_put_status(QDict *qdict, const char *name,
uint64_t trans, uint64_t rem, uint64_t total)
{
QObject *obj;
obj = qobject_from_jsonf("{ 'transferred': %" PRId64 ", "
"'remaining': %" PRId64 ", "
"'total': %" PRId64 " }", trans, rem, total);
qdict_put_obj(qdict, name, obj);
}
void do_info_migrate(Monitor *mon, QObject **ret_data)
{
QDict *qdict;
MigrationState *s = current_migration;
if (s) {
switch (s->get_status(s)) {
case MIG_STATE_ACTIVE:
qdict = qdict_new();
qdict_put(qdict, "status", qstring_from_str("active"));
migrate_put_status(qdict, "ram", ram_bytes_transferred(),
ram_bytes_remaining(), ram_bytes_total());
if (blk_mig_active()) {
migrate_put_status(qdict, "disk", blk_mig_bytes_transferred(),
blk_mig_bytes_remaining(),
blk_mig_bytes_total());
}
*ret_data = QOBJECT(qdict);
break;
case MIG_STATE_COMPLETED:
*ret_data = qobject_from_jsonf("{ 'status': 'completed' }");
break;
case MIG_STATE_ERROR:
*ret_data = qobject_from_jsonf("{ 'status': 'failed' }");
break;
case MIG_STATE_CANCELLED:
*ret_data = qobject_from_jsonf("{ 'status': 'cancelled' }");
break;
}
}
}
/* shared migration helpers */
void migrate_fd_monitor_suspend(FdMigrationState *s, Monitor *mon)
{
s->mon = mon;
if (monitor_suspend(mon) == 0) {
DPRINTF("suspending monitor\n");
} else {
monitor_printf(mon, "terminal does not allow synchronous "
"migration, continuing detached\n");
}
}
void migrate_fd_error(FdMigrationState *s)
{
DPRINTF("setting error state\n");
s->state = MIG_STATE_ERROR;
notifier_list_notify(&migration_state_notifiers);
migrate_fd_cleanup(s);
}
int migrate_fd_cleanup(FdMigrationState *s)
{
int ret = 0;
qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL);
if (s->file) {
DPRINTF("closing file\n");
if (qemu_fclose(s->file) != 0) {
ret = -1;
}
s->file = NULL;
}
if (s->fd != -1)
close(s->fd);
/* Don't resume monitor until we've flushed all of the buffers */
if (s->mon) {
monitor_resume(s->mon);
}
s->fd = -1;
return ret;
}
void migrate_fd_put_notify(void *opaque)
{
FdMigrationState *s = opaque;
qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL);
qemu_file_put_notify(s->file);
}
ssize_t migrate_fd_put_buffer(void *opaque, const void *data, size_t size)
{
FdMigrationState *s = opaque;
ssize_t ret;
do {
ret = s->write(s, data, size);
} while (ret == -1 && ((s->get_error(s)) == EINTR));
if (ret == -1)
ret = -(s->get_error(s));
if (ret == -EAGAIN) {
qemu_set_fd_handler2(s->fd, NULL, NULL, migrate_fd_put_notify, s);
} else if (ret < 0) {
if (s->mon) {
monitor_resume(s->mon);
}
s->state = MIG_STATE_ERROR;
notifier_list_notify(&migration_state_notifiers);
}
return ret;
}
void migrate_fd_connect(FdMigrationState *s)
{
int ret;
s->file = qemu_fopen_ops_buffered(s,
s->bandwidth_limit,
migrate_fd_put_buffer,
migrate_fd_put_ready,
migrate_fd_wait_for_unfreeze,
migrate_fd_close);
DPRINTF("beginning savevm\n");
ret = qemu_savevm_state_begin(s->mon, s->file, s->mig_state.blk,
s->mig_state.shared);
if (ret < 0) {
DPRINTF("failed, %d\n", ret);
migrate_fd_error(s);
return;
}
migrate_fd_put_ready(s);
}
void migrate_fd_put_ready(void *opaque)
{
FdMigrationState *s = opaque;
if (s->state != MIG_STATE_ACTIVE) {
DPRINTF("put_ready returning because of non-active state\n");
return;
}
DPRINTF("iterate\n");
if (qemu_savevm_state_iterate(s->mon, s->file) == 1) {
int state;
int old_vm_running = vm_running;
DPRINTF("done iterating\n");
vm_stop(0);
if ((qemu_savevm_state_complete(s->mon, s->file)) < 0) {
if (old_vm_running) {
vm_start();
}
state = MIG_STATE_ERROR;
} else {
state = MIG_STATE_COMPLETED;
}
if (migrate_fd_cleanup(s) < 0) {
if (old_vm_running) {
vm_start();
}
state = MIG_STATE_ERROR;
}
s->state = state;
notifier_list_notify(&migration_state_notifiers);
}
}
int migrate_fd_get_status(MigrationState *mig_state)
{
FdMigrationState *s = migrate_to_fms(mig_state);
return s->state;
}
void migrate_fd_cancel(MigrationState *mig_state)
{
FdMigrationState *s = migrate_to_fms(mig_state);
if (s->state != MIG_STATE_ACTIVE)
return;
DPRINTF("cancelling migration\n");
s->state = MIG_STATE_CANCELLED;
notifier_list_notify(&migration_state_notifiers);
qemu_savevm_state_cancel(s->mon, s->file);
migrate_fd_cleanup(s);
}
void migrate_fd_release(MigrationState *mig_state)
{
FdMigrationState *s = migrate_to_fms(mig_state);
DPRINTF("releasing state\n");
if (s->state == MIG_STATE_ACTIVE) {
s->state = MIG_STATE_CANCELLED;
notifier_list_notify(&migration_state_notifiers);
migrate_fd_cleanup(s);
}
qemu_free(s);
}
void migrate_fd_wait_for_unfreeze(void *opaque)
{
FdMigrationState *s = opaque;
int ret;
DPRINTF("wait for unfreeze\n");
if (s->state != MIG_STATE_ACTIVE)
return;
do {
fd_set wfds;
FD_ZERO(&wfds);
FD_SET(s->fd, &wfds);
ret = select(s->fd + 1, NULL, &wfds, NULL, NULL);
} while (ret == -1 && (s->get_error(s)) == EINTR);
}
int migrate_fd_close(void *opaque)
{
FdMigrationState *s = opaque;
qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL);
return s->close(s);
}
void add_migration_state_change_notifier(Notifier *notify)
{
notifier_list_add(&migration_state_notifiers, notify);
}
void remove_migration_state_change_notifier(Notifier *notify)
{
notifier_list_remove(&migration_state_notifiers, notify);
}
int get_migration_state(void)
{
if (current_migration) {
return migrate_fd_get_status(current_migration);
} else {
return MIG_STATE_ERROR;
}
}
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