qemu/migration.c
Gerd Hoffmann 7b5d3aa2cc wakeup on migration
Wakeup the guest when the live part of the migation is finished.
This avoids being in suspended state on migration, so we don't
have to save the is_suspended bit.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>
2012-05-08 14:29:14 -03:00

465 lines
11 KiB
C

/*
* 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 "migration.h"
#include "monitor.h"
#include "buffered_file.h"
#include "sysemu.h"
#include "block.h"
#include "qemu_socket.h"
#include "block-migration.h"
#include "qmp-commands.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
enum {
MIG_STATE_ERROR,
MIG_STATE_SETUP,
MIG_STATE_CANCELLED,
MIG_STATE_ACTIVE,
MIG_STATE_COMPLETED,
};
#define MAX_THROTTLE (32 << 20) /* Migration speed throttling */
static NotifierList migration_state_notifiers =
NOTIFIER_LIST_INITIALIZER(migration_state_notifiers);
/* When we add fault tolerance, we could have several
migrations at once. For now we don't need to add
dynamic creation of migration */
static MigrationState *migrate_get_current(void)
{
static MigrationState current_migration = {
.state = MIG_STATE_SETUP,
.bandwidth_limit = MAX_THROTTLE,
};
return &current_migration;
}
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");
bdrv_clear_incoming_migration_all();
/* Make sure all file formats flush their mutable metadata */
bdrv_invalidate_cache_all();
if (autostart) {
vm_start();
} else {
runstate_set(RUN_STATE_PRELAUNCH);
}
}
/* 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;
}
MigrationInfo *qmp_query_migrate(Error **errp)
{
MigrationInfo *info = g_malloc0(sizeof(*info));
MigrationState *s = migrate_get_current();
switch (s->state) {
case MIG_STATE_SETUP:
/* no migration has happened ever */
break;
case MIG_STATE_ACTIVE:
info->has_status = true;
info->status = g_strdup("active");
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();
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();
}
break;
case MIG_STATE_COMPLETED:
info->has_status = true;
info->status = g_strdup("completed");
break;
case MIG_STATE_ERROR:
info->has_status = true;
info->status = g_strdup("failed");
break;
case MIG_STATE_CANCELLED:
info->has_status = true;
info->status = g_strdup("cancelled");
break;
}
return info;
}
/* shared migration helpers */
static int migrate_fd_cleanup(MigrationState *s)
{
int ret = 0;
qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL);
if (s->file) {
DPRINTF("closing file\n");
ret = qemu_fclose(s->file);
s->file = NULL;
}
if (s->fd != -1) {
close(s->fd);
s->fd = -1;
}
return ret;
}
void migrate_fd_error(MigrationState *s)
{
DPRINTF("setting error state\n");
s->state = MIG_STATE_ERROR;
notifier_list_notify(&migration_state_notifiers, s);
migrate_fd_cleanup(s);
}
static void migrate_fd_completed(MigrationState *s)
{
DPRINTF("setting completed state\n");
if (migrate_fd_cleanup(s) < 0) {
s->state = MIG_STATE_ERROR;
} else {
s->state = MIG_STATE_COMPLETED;
runstate_set(RUN_STATE_POSTMIGRATE);
}
notifier_list_notify(&migration_state_notifiers, s);
}
static void migrate_fd_put_notify(void *opaque)
{
MigrationState *s = opaque;
qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL);
qemu_file_put_notify(s->file);
if (s->file && qemu_file_get_error(s->file)) {
migrate_fd_error(s);
}
}
static ssize_t migrate_fd_put_buffer(void *opaque, const void *data,
size_t size)
{
MigrationState *s = opaque;
ssize_t ret;
if (s->state != MIG_STATE_ACTIVE) {
return -EIO;
}
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;
}
static void migrate_fd_put_ready(void *opaque)
{
MigrationState *s = opaque;
int ret;
if (s->state != MIG_STATE_ACTIVE) {
DPRINTF("put_ready returning because of non-active state\n");
return;
}
DPRINTF("iterate\n");
ret = qemu_savevm_state_iterate(s->file);
if (ret < 0) {
migrate_fd_error(s);
} else if (ret == 1) {
int old_vm_running = runstate_is_running();
DPRINTF("done iterating\n");
qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER);
vm_stop_force_state(RUN_STATE_FINISH_MIGRATE);
if (qemu_savevm_state_complete(s->file) < 0) {
migrate_fd_error(s);
} else {
migrate_fd_completed(s);
}
if (s->state != MIG_STATE_COMPLETED) {
if (old_vm_running) {
vm_start();
}
}
}
}
static void migrate_fd_cancel(MigrationState *s)
{
if (s->state != MIG_STATE_ACTIVE)
return;
DPRINTF("cancelling migration\n");
s->state = MIG_STATE_CANCELLED;
notifier_list_notify(&migration_state_notifiers, s);
qemu_savevm_state_cancel(s->file);
migrate_fd_cleanup(s);
}
static void migrate_fd_wait_for_unfreeze(void *opaque)
{
MigrationState *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);
if (ret == -1) {
qemu_file_set_error(s->file, -s->get_error(s));
}
}
static int migrate_fd_close(void *opaque)
{
MigrationState *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_remove(notify);
}
bool migration_is_active(MigrationState *s)
{
return s->state == MIG_STATE_ACTIVE;
}
bool migration_has_finished(MigrationState *s)
{
return s->state == MIG_STATE_COMPLETED;
}
bool migration_has_failed(MigrationState *s)
{
return (s->state == MIG_STATE_CANCELLED ||
s->state == MIG_STATE_ERROR);
}
void migrate_fd_connect(MigrationState *s)
{
int ret;
s->state = MIG_STATE_ACTIVE;
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, s->blk, s->shared);
if (ret < 0) {
DPRINTF("failed, %d\n", ret);
migrate_fd_error(s);
return;
}
migrate_fd_put_ready(s);
}
static MigrationState *migrate_init(int blk, int inc)
{
MigrationState *s = migrate_get_current();
int64_t bandwidth_limit = s->bandwidth_limit;
memset(s, 0, sizeof(*s));
s->bandwidth_limit = bandwidth_limit;
s->blk = blk;
s->shared = inc;
s->bandwidth_limit = bandwidth_limit;
s->state = MIG_STATE_SETUP;
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(const char *uri, bool has_blk, bool blk,
bool has_inc, bool inc, bool has_detach, bool detach,
Error **errp)
{
MigrationState *s = migrate_get_current();
const char *p;
int ret;
if (s->state == MIG_STATE_ACTIVE) {
error_set(errp, QERR_MIGRATION_ACTIVE);
return;
}
if (qemu_savevm_state_blocked(errp)) {
return;
}
if (migration_blockers) {
*errp = error_copy(migration_blockers->data);
return;
}
s = migrate_init(blk, inc);
if (strstart(uri, "tcp:", &p)) {
ret = tcp_start_outgoing_migration(s, p);
#if !defined(WIN32)
} else if (strstart(uri, "exec:", &p)) {
ret = exec_start_outgoing_migration(s, p);
} else if (strstart(uri, "unix:", &p)) {
ret = unix_start_outgoing_migration(s, p);
} else if (strstart(uri, "fd:", &p)) {
ret = fd_start_outgoing_migration(s, p);
#endif
} else {
error_set(errp, QERR_INVALID_PARAMETER_VALUE, "uri", "a valid migration protocol");
return;
}
if (ret < 0) {
DPRINTF("migration failed: %s\n", strerror(-ret));
/* FIXME: we should return meaningful errors */
error_set(errp, QERR_UNDEFINED_ERROR);
return;
}
notifier_list_notify(&migration_state_notifiers, s);
}
void qmp_migrate_cancel(Error **errp)
{
migrate_fd_cancel(migrate_get_current());
}
void qmp_migrate_set_speed(int64_t value, Error **errp)
{
MigrationState *s;
if (value < 0) {
value = 0;
}
s = migrate_get_current();
s->bandwidth_limit = value;
qemu_file_set_rate_limit(s->file, s->bandwidth_limit);
}
void qmp_migrate_set_downtime(double value, Error **errp)
{
value *= 1e9;
value = MAX(0, MIN(UINT64_MAX, value));
max_downtime = (uint64_t)value;
}