void qemu_put_buffer(QEMUFile *f, const uint8_t *buf, size_t size)
{
size_t l;
if (f->last_error) {
return;
}
while (size > 0) {
l = IO_BUF_SIZE - f->buf_index;
if (l > size) {
l = size;
}
memcpy(f->buf + f->buf_index, buf, l);
f->bytes_xfer += l;
add_to_iovec(f, f->buf + f->buf_index, l);
f->buf_index += l;
if (f->buf_index == IO_BUF_SIZE) {
qemu_fflush(f);
}
if (qemu_file_get_error(f)) {
break;
}
buf += l;
size -= l;
}
}
static int buffered_put_buffer(void *opaque, const uint8_t *buf,
int64_t pos, int size)
{
MigrationState *s = opaque;
ssize_t error;
DPRINTF("putting %d bytes at %" PRId64 "\n", size, pos);
error = qemu_file_get_error(s->file);
if (error) {
DPRINTF("flush when error, bailing: %s\n", strerror(-error));
return error;
}
if (size <= 0) {
return size;
}
if (size > (s->buffer_capacity - s->buffer_size)) {
DPRINTF("increasing buffer capacity from %zu by %zu\n",
s->buffer_capacity, size + 1024);
s->buffer_capacity += size + 1024;
s->buffer = g_realloc(s->buffer, s->buffer_capacity);
}
memcpy(s->buffer + s->buffer_size, buf, size);
s->buffer_size += size;
return size;
}
static int buffered_close(void *opaque)
{
QEMUFileBuffered *s = opaque;
ssize_t ret = 0;
int ret2;
DPRINTF("closing\n");
s->xfer_limit = INT_MAX;
while (!qemu_file_get_error(s->file) && s->buffer_size) {
ret = buffered_flush(s);
if (ret < 0) {
break;
}
if (s->freeze_output) {
ret = migrate_fd_wait_for_unfreeze(s->migration_state);
if (ret < 0) {
break;
}
}
}
ret2 = migrate_fd_close(s->migration_state);
if (ret >= 0) {
ret = ret2;
}
qemu_del_timer(s->timer);
qemu_free_timer(s->timer);
g_free(s->buffer);
g_free(s);
return ret;
}
static int buffered_put_buffer(void *opaque, const uint8_t *buf, int64_t pos, int size)
{
QEMUFileBuffered *s = opaque;
int offset = 0, error;
ssize_t ret;
DPRINTF("putting %d bytes at %" PRId64 "\n", size, pos);
error = qemu_file_get_error(s->file);
if (error) {
DPRINTF("flush when error, bailing: %s\n", strerror(-error));
return error;
}
DPRINTF("unfreezing output\n");
s->freeze_output = 0;
buffered_flush(s);
while (!s->freeze_output && offset < size) {
if (s->bytes_xfer > s->xfer_limit) {
DPRINTF("transfer limit exceeded when putting\n");
break;
}
ret = s->put_buffer(s->opaque, buf + offset, size - offset);
if (ret == -EAGAIN) {
DPRINTF("backend not ready, freezing\n");
s->freeze_output = 1;
break;
}
if (ret <= 0) {
DPRINTF("error putting\n");
qemu_file_set_error(s->file, ret);
offset = -EINVAL;
break;
}
DPRINTF("put %zd byte(s)\n", ret);
offset += ret;
s->bytes_xfer += ret;
}
if (offset >= 0) {
DPRINTF("buffering %d bytes\n", size - offset);
buffered_append(s, buf + offset, size - offset);
offset = size;
}
if (pos == 0 && size == 0) {
DPRINTF("file is ready\n");
if (s->bytes_xfer <= s->xfer_limit) {
DPRINTF("notifying client\n");
s->put_ready(s->opaque);
}
}
return offset;
}
int qemu_file_rate_limit(QEMUFile *f)
{
if (qemu_file_get_error(f)) {
return 1;
}
if (f->xfer_limit > 0 && f->bytes_xfer > f->xfer_limit) {
return 1;
}
return 0;
}
static void save_vmstate(const VMStateDescription *desc, void *obj)
{
QEMUFile *f = open_test_file(true);
/* Save file with vmstate */
vmstate_save_state(f, desc, obj);
qemu_put_byte(f, QEMU_VM_EOF);
g_assert(!qemu_file_get_error(f));
qemu_fclose(f);
}
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 int load_vmstate_one(const VMStateDescription *desc, void *obj,
int version, uint8_t *wire, size_t size)
{
QEMUFile *f;
int ret;
f = open_test_file(true);
qemu_put_buffer(f, wire, size);
qemu_fclose(f);
f = open_test_file(false);
ret = vmstate_load_state(f, desc, obj, version);
if (ret) {
g_assert(qemu_file_get_error(f));
} else{
g_assert(!qemu_file_get_error(f));
}
qemu_fclose(f);
return ret;
}
static int64_t buffered_set_rate_limit(void *opaque, int64_t new_rate)
{
MigrationState *s = opaque;
if (qemu_file_get_error(s->file)) {
goto out;
}
if (new_rate > SIZE_MAX) {
new_rate = SIZE_MAX;
}
s->xfer_limit = new_rate / XFER_LIMIT_RATIO;
out:
return s->xfer_limit;
}
static int64_t buffered_set_rate_limit(void *opaque, int64_t new_rate)
{
QEMUFileBuffered *s = opaque;
if (qemu_file_get_error(s->file)) {
goto out;
}
if (new_rate > SIZE_MAX) {
new_rate = SIZE_MAX;
}
s->xfer_limit = new_rate / 10;
out:
return s->xfer_limit;
}
/*
* The meaning of the return values is:
* 0: We can continue sending
* 1: Time to stop
* negative: There has been an error
*/
static int buffered_rate_limit(void *opaque)
{
MigrationState *s = opaque;
int ret;
ret = qemu_file_get_error(s->file);
if (ret) {
return ret;
}
if (s->bytes_xfer >= s->xfer_limit) {
return 1;
}
return 0;
}
static int buffered_rate_limit(void *opaque)
{
QEMUFileBuffered *s = opaque;
int ret;
ret = qemu_file_get_error(s->file);
if (ret) {
return ret;
}
if (s->freeze_output)
return 1;
if (s->bytes_xfer > s->xfer_limit)
return 1;
return 0;
}
static void buffered_rate_tick(void *opaque)
{
QEMUFileBuffered *s = opaque;
if (qemu_file_get_error(s->file)) {
buffered_close(s);
return;
}
qemu_mod_timer(s->timer, qemu_get_clock_ms(rt_clock) + 100);
if (s->freeze_output)
return;
s->bytes_xfer = 0;
buffered_put_buffer(s, NULL, 0, 0);
}
static COLOMessage colo_receive_message(QEMUFile *f, Error **errp)
{
COLOMessage msg;
int ret;
msg = qemu_get_be32(f);
ret = qemu_file_get_error(f);
if (ret < 0) {
error_setg_errno(errp, -ret, "Can't receive COLO message");
return msg;
}
if (msg >= COLO_MESSAGE__MAX) {
error_setg(errp, "%s: Invalid message", __func__);
return msg;
}
trace_colo_receive_message(COLOMessage_lookup[msg]);
return msg;
}
static void colo_send_message(QEMUFile *f, COLOMessage msg,
Error **errp)
{
int ret;
if (msg >= COLO_MESSAGE__MAX) {
error_setg(errp, "%s: Invalid message", __func__);
return;
}
qemu_put_be32(f, msg);
qemu_fflush(f);
ret = qemu_file_get_error(f);
if (ret < 0) {
error_setg_errno(errp, -ret, "Can't send COLO message");
}
trace_colo_send_message(COLOMessage_lookup[msg]);
}
/*
* Give a QEMUFile* off the same socket but data in the opposite
* direction.
*/
static QEMUFile *socket_get_return_path(void *opaque)
{
QEMUFileSocket *forward = opaque;
QEMUFileSocket *reverse;
if (qemu_file_get_error(forward->file)) {
/* If the forward file is in error, don't try and open a return */
return NULL;
}
reverse = g_malloc0(sizeof(QEMUFileSocket));
reverse->fd = forward->fd;
/* I don't think there's a better way to tell which direction 'this' is */
if (forward->file->ops->get_buffer != NULL) {
/* being called from the read side, so we need to be able to write */
return qemu_fopen_ops(reverse, &socket_return_write_ops);
} else {
return qemu_fopen_ops(reverse, &socket_return_read_ops);
}
}
static void colo_send_message_value(QEMUFile *f, COLOMessage msg,
uint64_t value, Error **errp)
{
Error *local_err = NULL;
int ret;
colo_send_message(f, msg, &local_err);
if (local_err) {
error_propagate(errp, local_err);
return;
}
qemu_put_be64(f, value);
qemu_fflush(f);
ret = qemu_file_get_error(f);
if (ret < 0) {
error_setg_errno(errp, -ret, "Failed to send value for message:%s",
COLOMessage_lookup[msg]);
}
}
/*
* Give a QEMUFile* off the same socket but data in the opposite
* direction.
*/
static QEMUFile *socket_dup_return_path(void *opaque)
{
QEMUFileSocket *qfs = opaque;
int revfd;
bool this_is_read;
QEMUFile *result;
if (qemu_file_get_error(qfs->file)) {
/* If the forward file is in error, don't try and open a return */
return NULL;
}
/* I don't think there's a better way to tell which direction 'this' is */
this_is_read = qfs->file->ops->get_buffer != NULL;
revfd = dup(qfs->fd);
if (revfd == -1) {
error_report("Error duplicating fd for return path: %s",
strerror(errno));
return NULL;
}
result = qemu_fopen_socket(revfd, this_is_read ? "wb" : "rb");
if (!result) {
close(revfd);
}
if (this_is_read) {
/* The qemu_fopen_socket "wb" will mark the socket blocking,
* which would be OK for the return path, but the semantics
* of non-blocking is that it follows the underlying connection
* not the fd number, and thus setting the return path non-blocking
* ends up setting the forward path blocking, which we don't want
*/
qemu_set_nonblock(revfd);
}
return result;
}
static void compare_vmstate(uint8_t *wire, size_t size)
{
QEMUFile *f = open_test_file(false);
uint8_t result[size];
/* read back as binary */
g_assert_cmpint(qemu_get_buffer(f, result, sizeof(result)), ==,
sizeof(result));
g_assert(!qemu_file_get_error(f));
/* Compare that what is on the file is the same that what we
expected to be there */
SUCCESS(memcmp(result, wire, sizeof(result)));
/* Must reach EOF */
qemu_get_byte(f);
g_assert_cmpint(qemu_file_get_error(f), ==, -EIO);
qemu_fclose(f);
}
static uint64_t colo_receive_message_value(QEMUFile *f, uint32_t expect_msg,
Error **errp)
{
Error *local_err = NULL;
uint64_t value;
int ret;
colo_receive_check_message(f, expect_msg, &local_err);
if (local_err) {
error_propagate(errp, local_err);
return 0;
}
value = qemu_get_be64(f);
ret = qemu_file_get_error(f);
if (ret < 0) {
error_setg_errno(errp, -ret, "Failed to get value for COLO message: %s",
COLOMessage_lookup[expect_msg]);
}
return value;
}
static void buffered_rate_tick(void *opaque)
{
QEMUFileBuffered *s = opaque;
if (qemu_file_get_error(s->file)) {
buffered_close(s);
return;
}
qemu_mod_timer(s->timer, qemu_get_clock_ms(rt_clock) + 100);
if (s->freeze_output)
return;
s->bytes_xfer = 0;
buffered_flush(s);
/* Add some checks around this */
s->put_ready(s->opaque);
}
static int buffered_close(void *opaque)
{
QEMUFileBuffered *s = opaque;
int ret;
DPRINTF("closing\n");
while (!qemu_file_get_error(s->file) && s->buffer_size) {
buffered_flush(s);
if (s->freeze_output)
s->wait_for_unfreeze(s->opaque);
}
ret = s->close(s->opaque);
qemu_del_timer(s->timer);
qemu_free_timer(s->timer);
g_free(s->buffer);
g_free(s);
return ret;
}
/** Closes the file
*
* Returns negative error value if any error happened on previous operations or
* while closing the file. Returns 0 or positive number on success.
*
* The meaning of return value on success depends on the specific backend
* being used.
*/
int qemu_fclose(QEMUFile *f)
{
int ret;
qemu_fflush(f);
ret = qemu_file_get_error(f);
if (f->ops->close) {
int ret2 = f->ops->close(f->opaque);
if (ret >= 0) {
ret = ret2;
}
}
/* If any error was spotted before closing, we should report it
* instead of the close() return value.
*/
if (f->last_error) {
ret = f->last_error;
}
g_free(f);
trace_qemu_file_fclose();
return ret;
}
static void buffered_flush(QEMUFileBuffered *s)
{
size_t offset = 0;
int error;
error = qemu_file_get_error(s->file);
if (error != 0) {
DPRINTF("flush when error, bailing: %s\n", strerror(-error));
return;
}
DPRINTF("flushing %zu byte(s) of data\n", s->buffer_size);
while (offset < s->buffer_size) {
ssize_t ret;
ret = s->put_buffer(s->opaque, s->buffer + offset,
s->buffer_size - offset);
if (ret == -EAGAIN) {
DPRINTF("backend not ready, freezing\n");
s->freeze_output = 1;
break;
}
if (ret <= 0) {
DPRINTF("error flushing data, %zd\n", ret);
qemu_file_set_error(s->file, ret);
break;
} else {
DPRINTF("flushed %zd byte(s)\n", ret);
offset += ret;
}
}
DPRINTF("flushed %zu of %zu byte(s)\n", offset, s->buffer_size);
memmove(s->buffer, s->buffer + offset, s->buffer_size - offset);
s->buffer_size -= offset;
}
static int buffered_close(void *opaque)
{
MigrationState *s = opaque;
ssize_t ret = 0;
int ret2;
DPRINTF("closing\n");
s->xfer_limit = INT_MAX;
while (!qemu_file_get_error(s->file) && s->buffer_size) {
ret = buffered_flush(s);
if (ret < 0) {
break;
}
}
ret2 = migrate_fd_close(s);
if (ret >= 0) {
ret = ret2;
}
s->complete = true;
return ret;
}
static int buffered_put_buffer(void *opaque, const uint8_t *buf, int64_t pos, int size)
{
QEMUFileBuffered *s = opaque;
ssize_t error;
DPRINTF("putting %d bytes at %" PRId64 "\n", size, pos);
error = qemu_file_get_error(s->file);
if (error) {
DPRINTF("flush when error, bailing: %s\n", strerror(-error));
return error;
}
DPRINTF("unfreezing output\n");
s->freeze_output = 0;
if (size > 0) {
DPRINTF("buffering %d bytes\n", size);
buffered_append(s, buf, size);
}
error = buffered_flush(s);
if (error < 0) {
DPRINTF("buffered flush error. bailing: %s\n", strerror(-error));
return error;
}
if (pos == 0 && size == 0) {
DPRINTF("file is ready\n");
if (!s->freeze_output && s->bytes_xfer < s->xfer_limit) {
DPRINTF("notifying client\n");
migrate_fd_put_ready(s->migration_state);
}
}
return size;
}
static void buffered_flush(QEMUFileBuffered *s)
{
size_t offset = 0;
int error;
error = qemu_file_get_error(s->file);
if (error != 0) {
DPRINTF("flush when error, bailing: %s\n", strerror(-error));
return;
}
DPRINTF("flushing %zu byte(s) of data\n", s->buffer_size);
while (offset < s->buffer_size) {
ssize_t ret;
ret = s->put_buffer(s->opaque, s->buffer + offset,
s->buffer_size - offset);
if (ret == -EAGAIN) {
DPRINTF("backend not ready, freezing\n");
DVERYDETAIL{
printf("bflush : backend not ready, freezing\n");
fflush(stdout);}
s->freeze_output = 1;
break;
}
if (ret <= 0) {
DPRINTF("error flushing data, %zd\n", ret);
DVERYDETAIL{
printf("bflush :error flushing data, %zd\n", ret);
fflush(stdout);}
qemu_file_set_error(s->file, ret);
break;
} else {
static int colo_do_checkpoint_transaction(MigrationState *s,
QIOChannelBuffer *bioc,
QEMUFile *fb)
{
Error *local_err = NULL;
int ret = -1;
colo_send_message(s->to_dst_file, COLO_MESSAGE_CHECKPOINT_REQUEST,
&local_err);
if (local_err) {
goto out;
}
colo_receive_check_message(s->rp_state.from_dst_file,
COLO_MESSAGE_CHECKPOINT_REPLY, &local_err);
if (local_err) {
goto out;
}
/* Reset channel-buffer directly */
qio_channel_io_seek(QIO_CHANNEL(bioc), 0, 0, NULL);
bioc->usage = 0;
qemu_mutex_lock_iothread();
if (failover_get_state() != FAILOVER_STATUS_NONE) {
qemu_mutex_unlock_iothread();
goto out;
}
vm_stop_force_state(RUN_STATE_COLO);
qemu_mutex_unlock_iothread();
trace_colo_vm_state_change("run", "stop");
/*
* Failover request bh could be called after vm_stop_force_state(),
* So we need check failover_request_is_active() again.
*/
if (failover_get_state() != FAILOVER_STATUS_NONE) {
goto out;
}
/* Disable block migration */
s->params.blk = 0;
s->params.shared = 0;
qemu_savevm_state_header(fb);
qemu_savevm_state_begin(fb, &s->params);
qemu_mutex_lock_iothread();
qemu_savevm_state_complete_precopy(fb, false);
qemu_mutex_unlock_iothread();
qemu_fflush(fb);
colo_send_message(s->to_dst_file, COLO_MESSAGE_VMSTATE_SEND, &local_err);
if (local_err) {
goto out;
}
/*
* We need the size of the VMstate data in Secondary side,
* With which we can decide how much data should be read.
*/
colo_send_message_value(s->to_dst_file, COLO_MESSAGE_VMSTATE_SIZE,
bioc->usage, &local_err);
if (local_err) {
goto out;
}
qemu_put_buffer(s->to_dst_file, bioc->data, bioc->usage);
qemu_fflush(s->to_dst_file);
ret = qemu_file_get_error(s->to_dst_file);
if (ret < 0) {
goto out;
}
colo_receive_check_message(s->rp_state.from_dst_file,
COLO_MESSAGE_VMSTATE_RECEIVED, &local_err);
if (local_err) {
goto out;
}
colo_receive_check_message(s->rp_state.from_dst_file,
COLO_MESSAGE_VMSTATE_LOADED, &local_err);
if (local_err) {
goto out;
}
ret = 0;
qemu_mutex_lock_iothread();
vm_start();
qemu_mutex_unlock_iothread();
trace_colo_vm_state_change("stop", "run");
out:
if (local_err) {
error_report_err(local_err);
}
return ret;
}
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;
DPRINTF("beginning savevm\n");
qemu_savevm_state_begin(s->file, &s->params);
s->setup_time = qemu_clock_get_ms(QEMU_CLOCK_HOST) - setup_start;
migrate_set_state(s, MIG_STATE_SETUP, MIG_STATE_ACTIVE);
DPRINTF("setup complete\n");
while (s->state == MIG_STATE_ACTIVE) {
int64_t current_time;
uint64_t pending_size;
if (!qemu_file_rate_limit(s->file)) {
DPRINTF("iterate\n");
pending_size = qemu_savevm_state_pending(s->file, max_size);
DPRINTF("pending size %" PRIu64 " max %" PRIu64 "\n",
pending_size, max_size);
if (pending_size && pending_size >= max_size) {
qemu_savevm_state_iterate(s->file);
} else {
int ret;
DPRINTF("done iterating\n");
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 = 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, MIG_STATE_ACTIVE, MIG_STATE_ERROR);
break;
}
if (!qemu_file_get_error(s->file)) {
migrate_set_state(s, MIG_STATE_ACTIVE, MIG_STATE_COMPLETED);
break;
}
}
}
if (qemu_file_get_error(s->file)) {
migrate_set_state(s, MIG_STATE_ACTIVE, MIG_STATE_ERROR);
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;
DPRINTF("transferred %" PRIu64 " time_spent %" PRIu64
" bandwidth %g max_size %" PRId64 "\n",
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 == MIG_STATE_COMPLETED) {
int64_t end_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
s->total_time = end_time - s->total_time;
s->downtime = end_time - start_time;
runstate_set(RUN_STATE_POSTMIGRATE);
} else {
if (old_vm_running) {
vm_start();
}
}
qemu_bh_schedule(s->cleanup_bh);
qemu_mutex_unlock_iothread();
return NULL;
}
static int colo_do_checkpoint_transaction(MigrationState *s,
QIOChannelBuffer *bioc,
QEMUFile *fb)
{
Error *local_err = NULL;
int ret = -1;
colo_send_message(s->to_dst_file, COLO_MESSAGE_CHECKPOINT_REQUEST,
&local_err);
if (local_err) {
goto out;
}
colo_receive_check_message(s->rp_state.from_dst_file,
COLO_MESSAGE_CHECKPOINT_REPLY, &local_err);
if (local_err) {
goto out;
}
/* Reset channel-buffer directly */
qio_channel_io_seek(QIO_CHANNEL(bioc), 0, 0, NULL);
bioc->usage = 0;
qemu_mutex_lock_iothread();
if (failover_get_state() != FAILOVER_STATUS_NONE) {
qemu_mutex_unlock_iothread();
goto out;
}
vm_stop_force_state(RUN_STATE_COLO);
qemu_mutex_unlock_iothread();
trace_colo_vm_state_change("run", "stop");
/*
* Failover request bh could be called after vm_stop_force_state(),
* So we need check failover_request_is_active() again.
*/
if (failover_get_state() != FAILOVER_STATUS_NONE) {
goto out;
}
colo_notify_compares_event(NULL, COLO_EVENT_CHECKPOINT, &local_err);
if (local_err) {
goto out;
}
/* Disable block migration */
migrate_set_block_enabled(false, &local_err);
qemu_mutex_lock_iothread();
#ifdef CONFIG_REPLICATION
replication_do_checkpoint_all(&local_err);
if (local_err) {
qemu_mutex_unlock_iothread();
goto out;
}
#else
abort();
#endif
colo_send_message(s->to_dst_file, COLO_MESSAGE_VMSTATE_SEND, &local_err);
if (local_err) {
qemu_mutex_unlock_iothread();
goto out;
}
/* Note: device state is saved into buffer */
ret = qemu_save_device_state(fb);
qemu_mutex_unlock_iothread();
if (ret < 0) {
goto out;
}
/*
* Only save VM's live state, which not including device state.
* TODO: We may need a timeout mechanism to prevent COLO process
* to be blocked here.
*/
qemu_savevm_live_state(s->to_dst_file);
qemu_fflush(fb);
/*
* We need the size of the VMstate data in Secondary side,
* With which we can decide how much data should be read.
*/
colo_send_message_value(s->to_dst_file, COLO_MESSAGE_VMSTATE_SIZE,
bioc->usage, &local_err);
if (local_err) {
goto out;
}
qemu_put_buffer(s->to_dst_file, bioc->data, bioc->usage);
qemu_fflush(s->to_dst_file);
ret = qemu_file_get_error(s->to_dst_file);
if (ret < 0) {
goto out;
}
colo_receive_check_message(s->rp_state.from_dst_file,
COLO_MESSAGE_VMSTATE_RECEIVED, &local_err);
if (local_err) {
goto out;
}
colo_receive_check_message(s->rp_state.from_dst_file,
COLO_MESSAGE_VMSTATE_LOADED, &local_err);
if (local_err) {
goto out;
}
ret = 0;
qemu_mutex_lock_iothread();
vm_start();
qemu_mutex_unlock_iothread();
trace_colo_vm_state_change("stop", "run");
out:
if (local_err) {
error_report_err(local_err);
}
return ret;
}