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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"
//#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 uint32_t max_throttle = (32 << 20);
static MigrationState *current_migration;
void qemu_start_incoming_migration(const char *uri)
{
const char *p;
if (strstart(uri, "tcp:", &p))
tcp_start_incoming_migration(p);
#if !defined(WIN32)
else if (strstart(uri, "exec:", &p))
exec_start_incoming_migration(p);
#endif
else
fprintf(stderr, "unknown migration protocol: %s\n", uri);
}
void do_migrate(Monitor *mon, int detach, const char *uri)
{
MigrationState *s = NULL;
const char *p;
if (strstart(uri, "tcp:", &p))
s = tcp_start_outgoing_migration(p, max_throttle, detach);
#if !defined(WIN32)
else if (strstart(uri, "exec:", &p))
s = exec_start_outgoing_migration(p, max_throttle, detach);
#endif
else
monitor_printf(mon, "unknown migration protocol: %s\n", uri);
if (s == NULL)
monitor_printf(mon, "migration failed\n");
else {
if (current_migration)
current_migration->release(current_migration);
current_migration = s;
}
}
void do_migrate_cancel(Monitor *mon)
{
MigrationState *s = current_migration;
if (s)
s->cancel(s);
}
void do_migrate_set_speed(Monitor *mon, const char *value)
{
double d;
char *ptr;
FdMigrationState *s;
d = strtod(value, &ptr);
switch (*ptr) {
case 'G': case 'g':
d *= 1024;
case 'M': case 'm':
d *= 1024;
case 'K': case 'k':
d *= 1024;
default:
break;
}
max_throttle = (uint32_t)d;
s = migrate_to_fms(current_migration);
if (s) {
qemu_file_set_rate_limit(s->file, max_throttle);
}
}
/* 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;
}
void do_migrate_set_downtime(Monitor *mon, const char *value)
{
char *ptr;
double d;
d = strtod(value, &ptr);
if (!strcmp(ptr,"ms")) {
d *= 1000000;
} else if (!strcmp(ptr,"us")) {
d *= 1000;
} else if (!strcmp(ptr,"ns")) {
} else {
/* all else considered to be seconds */
d *= 1000000000;
}
max_downtime = (uint64_t)d;
}
void do_info_migrate(Monitor *mon)
{
MigrationState *s = current_migration;
if (s) {
monitor_printf(mon, "Migration status: ");
switch (s->get_status(s)) {
case MIG_STATE_ACTIVE:
monitor_printf(mon, "active\n");
monitor_printf(mon, "transferred ram: %" PRIu64 " kbytes\n", ram_bytes_transferred() >> 10);
monitor_printf(mon, "remaining ram: %" PRIu64 " kbytes\n", ram_bytes_remaining() >> 10);
monitor_printf(mon, "total ram: %" PRIu64 " kbytes\n", ram_bytes_total() >> 10);
break;
case MIG_STATE_COMPLETED:
monitor_printf(mon, "completed\n");
break;
case MIG_STATE_ERROR:
monitor_printf(mon, "failed\n");
break;
case MIG_STATE_CANCELLED:
monitor_printf(mon, "cancelled\n");
break;
}
}
}
/* shared migration helpers */
void migrate_fd_monitor_suspend(FdMigrationState *s)
{
s->mon_resume = cur_mon;
if (monitor_suspend(cur_mon) == 0)
dprintf("suspending monitor\n");
else
monitor_printf(cur_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;
migrate_fd_cleanup(s);
}
void migrate_fd_cleanup(FdMigrationState *s)
{
qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL);
if (s->file) {
dprintf("closing file\n");
qemu_fclose(s->file);
}
if (s->fd != -1)
close(s->fd);
/* Don't resume monitor until we've flushed all of the buffers */
if (s->mon_resume)
monitor_resume(s->mon_resume);
s->fd = -1;
}
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);
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->file);
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->file) == 1) {
int state;
dprintf("done iterating\n");
vm_stop(0);
bdrv_flush_all();
if ((qemu_savevm_state_complete(s->file)) < 0) {
vm_start();
state = MIG_STATE_ERROR;
} else {
state = MIG_STATE_COMPLETED;
}
migrate_fd_cleanup(s);
s->state = state;
}
}
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;
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;
migrate_fd_cleanup(s);
}
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);
}
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