[qemu.git] / migration / colo.c

/*
 * COarse-grain LOck-stepping Virtual Machines for Non-stop Service (COLO)
 * (a.k.a. Fault Tolerance or Continuous Replication)
 *
 * Copyright (c) 2016 HUAWEI TECHNOLOGIES CO., LTD.
 * Copyright (c) 2016 FUJITSU LIMITED
 * Copyright (c) 2016 Intel Corporation
 *
 * This work is licensed under the terms of the GNU GPL, version 2 or
 * later.  See the COPYING file in the top-level directory.
 */

#include "qemu/osdep.h"
#include "qemu/timer.h"
#include "sysemu/sysemu.h"
#include "migration/colo.h"
#include "io/channel-buffer.h"
#include "trace.h"
#include "qemu/error-report.h"
#include "qapi/error.h"
#include "migration/failover.h"

#define COLO_BUFFER_BASE_SIZE (4 * 1024 * 1024)

bool colo_supported(void)
{
    return true;
}

bool migration_in_colo_state(void)
{
    MigrationState *s = migrate_get_current();

    return (s->state == MIGRATION_STATUS_COLO);
}

bool migration_incoming_in_colo_state(void)
{
    MigrationIncomingState *mis = migration_incoming_get_current();

    return mis && (mis->state == MIGRATION_STATUS_COLO);
}

static bool colo_runstate_is_stopped(void)
{
    return runstate_check(RUN_STATE_COLO) || !runstate_is_running();
}

static void secondary_vm_do_failover(void)
{
    int old_state;
    MigrationIncomingState *mis = migration_incoming_get_current();

    migrate_set_state(&mis->state, MIGRATION_STATUS_COLO,
                      MIGRATION_STATUS_COMPLETED);

    if (!autostart) {
        error_report("\"-S\" qemu option will be ignored in secondary side");
        /* recover runstate to normal migration finish state */
        autostart = true;
    }

    old_state = failover_set_state(FAILOVER_STATUS_ACTIVE,
                                   FAILOVER_STATUS_COMPLETED);
    if (old_state != FAILOVER_STATUS_ACTIVE) {
        error_report("Incorrect state (%s) while doing failover for "
                     "secondary VM", FailoverStatus_lookup[old_state]);
        return;
    }
    /* For Secondary VM, jump to incoming co */
    if (mis->migration_incoming_co) {
        qemu_coroutine_enter(mis->migration_incoming_co);
    }
}

static void primary_vm_do_failover(void)
{
    MigrationState *s = migrate_get_current();
    int old_state;

    migrate_set_state(&s->state, MIGRATION_STATUS_COLO,
                      MIGRATION_STATUS_COMPLETED);

    old_state = failover_set_state(FAILOVER_STATUS_ACTIVE,
                                   FAILOVER_STATUS_COMPLETED);
    if (old_state != FAILOVER_STATUS_ACTIVE) {
        error_report("Incorrect state (%s) while doing failover for Primary VM",
                     FailoverStatus_lookup[old_state]);
        return;
    }
}

void colo_do_failover(MigrationState *s)
{
    /* Make sure VM stopped while failover happened. */
    if (!colo_runstate_is_stopped()) {
        vm_stop_force_state(RUN_STATE_COLO);
    }

    if (get_colo_mode() == COLO_MODE_PRIMARY) {
        primary_vm_do_failover();
    } else {
        secondary_vm_do_failover();
    }
}

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]);
}

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]);
    }
}

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_receive_check_message(QEMUFile *f, COLOMessage expect_msg,
                                       Error **errp)
{
    COLOMessage msg;
    Error *local_err = NULL;

    msg = colo_receive_message(f, &local_err);
    if (local_err) {
        error_propagate(errp, local_err);
        return;
    }
    if (msg != expect_msg) {
        error_setg(errp, "Unexpected COLO message %d, expected %d",
                          msg, expect_msg);
    }
}

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 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 colo_process_checkpoint(MigrationState *s)
{
    QIOChannelBuffer *bioc;
    QEMUFile *fb = NULL;
    int64_t current_time, checkpoint_time = qemu_clock_get_ms(QEMU_CLOCK_HOST);
    Error *local_err = NULL;
    int ret;

    failover_init_state();

    s->rp_state.from_dst_file = qemu_file_get_return_path(s->to_dst_file);
    if (!s->rp_state.from_dst_file) {
        error_report("Open QEMUFile from_dst_file failed");
        goto out;
    }

    /*
     * Wait for Secondary finish loading VM states and enter COLO
     * restore.
     */
    colo_receive_check_message(s->rp_state.from_dst_file,
                       COLO_MESSAGE_CHECKPOINT_READY, &local_err);
    if (local_err) {
        goto out;
    }
    bioc = qio_channel_buffer_new(COLO_BUFFER_BASE_SIZE);
    fb = qemu_fopen_channel_output(QIO_CHANNEL(bioc));
    object_unref(OBJECT(bioc));

    qemu_mutex_lock_iothread();
    vm_start();
    qemu_mutex_unlock_iothread();
    trace_colo_vm_state_change("stop", "run");

    while (s->state == MIGRATION_STATUS_COLO) {
        if (failover_get_state() != FAILOVER_STATUS_NONE) {
            error_report("failover request");
            goto out;
        }

        current_time = qemu_clock_get_ms(QEMU_CLOCK_HOST);
        if (current_time - checkpoint_time <
            s->parameters.x_checkpoint_delay) {
            int64_t delay_ms;

            delay_ms = s->parameters.x_checkpoint_delay -
                       (current_time - checkpoint_time);
            g_usleep(delay_ms * 1000);
        }
        ret = colo_do_checkpoint_transaction(s, bioc, fb);
        if (ret < 0) {
            goto out;
        }
        checkpoint_time = qemu_clock_get_ms(QEMU_CLOCK_HOST);
    }

out:
    /* Throw the unreported error message after exited from loop */
    if (local_err) {
        error_report_err(local_err);
    }

    if (fb) {
        qemu_fclose(fb);
    }

    if (s->rp_state.from_dst_file) {
        qemu_fclose(s->rp_state.from_dst_file);
    }
}

void migrate_start_colo_process(MigrationState *s)
{
    qemu_mutex_unlock_iothread();
    migrate_set_state(&s->state, MIGRATION_STATUS_ACTIVE,
                      MIGRATION_STATUS_COLO);
    colo_process_checkpoint(s);
    qemu_mutex_lock_iothread();
}

static void colo_wait_handle_message(QEMUFile *f, int *checkpoint_request,
                                     Error **errp)
{
    COLOMessage msg;
    Error *local_err = NULL;

    msg = colo_receive_message(f, &local_err);
    if (local_err) {
        error_propagate(errp, local_err);
        return;
    }

    switch (msg) {
    case COLO_MESSAGE_CHECKPOINT_REQUEST:
        *checkpoint_request = 1;
        break;
    default:
        *checkpoint_request = 0;
        error_setg(errp, "Got unknown COLO message: %d", msg);
        break;
    }
}

void *colo_process_incoming_thread(void *opaque)
{
    MigrationIncomingState *mis = opaque;
    QEMUFile *fb = NULL;
    QIOChannelBuffer *bioc = NULL; /* Cache incoming device state */
    uint64_t total_size;
    uint64_t value;
    Error *local_err = NULL;

    migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE,
                      MIGRATION_STATUS_COLO);

    failover_init_state();

    mis->to_src_file = qemu_file_get_return_path(mis->from_src_file);
    if (!mis->to_src_file) {
        error_report("COLO incoming thread: Open QEMUFile to_src_file failed");
        goto out;
    }
    /*
     * Note: the communication between Primary side and Secondary side
     * should be sequential, we set the fd to unblocked in migration incoming
     * coroutine, and here we are in the COLO incoming thread, so it is ok to
     * set the fd back to blocked.
     */
    qemu_file_set_blocking(mis->from_src_file, true);

    bioc = qio_channel_buffer_new(COLO_BUFFER_BASE_SIZE);
    fb = qemu_fopen_channel_input(QIO_CHANNEL(bioc));
    object_unref(OBJECT(bioc));

    colo_send_message(mis->to_src_file, COLO_MESSAGE_CHECKPOINT_READY,
                      &local_err);
    if (local_err) {
        goto out;
    }

    while (mis->state == MIGRATION_STATUS_COLO) {
        int request;

        colo_wait_handle_message(mis->from_src_file, &request, &local_err);
        if (local_err) {
            goto out;
        }
        assert(request);
        if (failover_get_state() != FAILOVER_STATUS_NONE) {
            error_report("failover request");
            goto out;
        }

        /* FIXME: This is unnecessary for periodic checkpoint mode */
        colo_send_message(mis->to_src_file, COLO_MESSAGE_CHECKPOINT_REPLY,
                     &local_err);
        if (local_err) {
            goto out;
        }

        colo_receive_check_message(mis->from_src_file,
                           COLO_MESSAGE_VMSTATE_SEND, &local_err);
        if (local_err) {
            goto out;
        }

        value = colo_receive_message_value(mis->from_src_file,
                                 COLO_MESSAGE_VMSTATE_SIZE, &local_err);
        if (local_err) {
            goto out;
        }

        /*
         * Read VM device state data into channel buffer,
         * It's better to re-use the memory allocated.
         * Here we need to handle the channel buffer directly.
         */
        if (value > bioc->capacity) {
            bioc->capacity = value;
            bioc->data = g_realloc(bioc->data, bioc->capacity);
        }
        total_size = qemu_get_buffer(mis->from_src_file, bioc->data, value);
        if (total_size != value) {
            error_report("Got %" PRIu64 " VMState data, less than expected"
                        " %" PRIu64, total_size, value);
            goto out;
        }
        bioc->usage = total_size;
        qio_channel_io_seek(QIO_CHANNEL(bioc), 0, 0, NULL);

        colo_send_message(mis->to_src_file, COLO_MESSAGE_VMSTATE_RECEIVED,
                     &local_err);
        if (local_err) {
            goto out;
        }

        qemu_mutex_lock_iothread();
        qemu_system_reset(VMRESET_SILENT);
        if (qemu_loadvm_state(fb) < 0) {
            error_report("COLO: loadvm failed");
            qemu_mutex_unlock_iothread();
            goto out;
        }
        qemu_mutex_unlock_iothread();

        colo_send_message(mis->to_src_file, COLO_MESSAGE_VMSTATE_LOADED,
                     &local_err);
        if (local_err) {
            goto out;
        }
    }

out:
    /* Throw the unreported error message after exited from loop */
    if (local_err) {
        error_report_err(local_err);
    }

    if (fb) {
        qemu_fclose(fb);
    }

    if (mis->to_src_file) {
        qemu_fclose(mis->to_src_file);
    }
    migration_incoming_exit_colo();

    return NULL;
}
Commit	Line	Data
35a6ed4f HZ	1	/*
	2	* COarse-grain LOck-stepping Virtual Machines for Non-stop Service (COLO)
	3	* (a.k.a. Fault Tolerance or Continuous Replication)
	4	*
	5	* Copyright (c) 2016 HUAWEI TECHNOLOGIES CO., LTD.
	6	* Copyright (c) 2016 FUJITSU LIMITED
	7	* Copyright (c) 2016 Intel Corporation
	8	*
	9	* This work is licensed under the terms of the GNU GPL, version 2 or
	10	* later. See the COPYING file in the top-level directory.
	11	*/
	12
	13	#include "qemu/osdep.h"
18cc23d7	14	#include "qemu/timer.h"
0b827d5e	15	#include "sysemu/sysemu.h"
35a6ed4f	16	#include "migration/colo.h"
a91246c9	17	#include "io/channel-buffer.h"
0b827d5e	18	#include "trace.h"
56ba83d2	19	#include "qemu/error-report.h"
4f97558e	20	#include "qapi/error.h"
d89e666e	21	#include "migration/failover.h"
35a6ed4f	22
a91246c9 HZ	23	#define COLO_BUFFER_BASE_SIZE (4 * 1024 * 1024)
a91246c9 HZ	24
35a6ed4f HZ	25	bool colo_supported(void)
35a6ed4f HZ	26	{
180fb750	27	return true;
35a6ed4f	28	}
0b827d5e HZ	29
	30	bool migration_in_colo_state(void)
	31	{
	32	MigrationState *s = migrate_get_current();
	33
	34	return (s->state == MIGRATION_STATUS_COLO);
	35	}
	36
25d0c16f HZ	37	bool migration_incoming_in_colo_state(void)
	38	{
	39	MigrationIncomingState *mis = migration_incoming_get_current();
	40
	41	return mis && (mis->state == MIGRATION_STATUS_COLO);
	42	}
	43
b3f7f0c5 HZ	44	static bool colo_runstate_is_stopped(void)
	45	{
	46	return runstate_check(RUN_STATE_COLO) \|\| !runstate_is_running();
	47	}
	48
9d2db376 HZ	49	static void secondary_vm_do_failover(void)
	50	{
	51	int old_state;
	52	MigrationIncomingState *mis = migration_incoming_get_current();
	53
	54	migrate_set_state(&mis->state, MIGRATION_STATUS_COLO,
	55	MIGRATION_STATUS_COMPLETED);
	56
	57	if (!autostart) {
	58	error_report("\"-S\" qemu option will be ignored in secondary side");
	59	/* recover runstate to normal migration finish state */
	60	autostart = true;
	61	}
	62
	63	old_state = failover_set_state(FAILOVER_STATUS_ACTIVE,
	64	FAILOVER_STATUS_COMPLETED);
	65	if (old_state != FAILOVER_STATUS_ACTIVE) {
	66	error_report("Incorrect state (%s) while doing failover for "
	67	"secondary VM", FailoverStatus_lookup[old_state]);
	68	return;
	69	}
	70	/* For Secondary VM, jump to incoming co */
	71	if (mis->migration_incoming_co) {
	72	qemu_coroutine_enter(mis->migration_incoming_co);
	73	}
	74	}
	75
b3f7f0c5 HZ	76	static void primary_vm_do_failover(void)
	77	{
	78	MigrationState *s = migrate_get_current();
	79	int old_state;
	80
	81	migrate_set_state(&s->state, MIGRATION_STATUS_COLO,
	82	MIGRATION_STATUS_COMPLETED);
	83
	84	old_state = failover_set_state(FAILOVER_STATUS_ACTIVE,
	85	FAILOVER_STATUS_COMPLETED);
	86	if (old_state != FAILOVER_STATUS_ACTIVE) {
	87	error_report("Incorrect state (%s) while doing failover for Primary VM",
	88	FailoverStatus_lookup[old_state]);
	89	return;
	90	}
	91	}
	92
	93	void colo_do_failover(MigrationState *s)
	94	{
	95	/* Make sure VM stopped while failover happened. */
	96	if (!colo_runstate_is_stopped()) {
	97	vm_stop_force_state(RUN_STATE_COLO);
	98	}
	99
	100	if (get_colo_mode() == COLO_MODE_PRIMARY) {
	101	primary_vm_do_failover();
9d2db376 HZ	102	} else {
9d2db376 HZ	103	secondary_vm_do_failover();
b3f7f0c5 HZ	104	}
	105	}
	106
4f97558e HZ	107	static void colo_send_message(QEMUFile *f, COLOMessage msg,
	108	Error **errp)
	109	{
	110	int ret;
	111
	112	if (msg >= COLO_MESSAGE__MAX) {
	113	error_setg(errp, "%s: Invalid message", __func__);
	114	return;
	115	}
	116	qemu_put_be32(f, msg);
	117	qemu_fflush(f);
	118
	119	ret = qemu_file_get_error(f);
	120	if (ret < 0) {
	121	error_setg_errno(errp, -ret, "Can't send COLO message");
	122	}
	123	trace_colo_send_message(COLOMessage_lookup[msg]);
	124	}
	125
a91246c9 HZ	126	static void colo_send_message_value(QEMUFile *f, COLOMessage msg,
	127	uint64_t value, Error **errp)
	128	{
	129	Error *local_err = NULL;
	130	int ret;
	131
	132	colo_send_message(f, msg, &local_err);
	133	if (local_err) {
	134	error_propagate(errp, local_err);
	135	return;
	136	}
	137	qemu_put_be64(f, value);
	138	qemu_fflush(f);
	139
	140	ret = qemu_file_get_error(f);
	141	if (ret < 0) {
	142	error_setg_errno(errp, -ret, "Failed to send value for message:%s",
	143	COLOMessage_lookup[msg]);
	144	}
	145	}
	146
4f97558e HZ	147	static COLOMessage colo_receive_message(QEMUFile f, Error *errp)
	148	{
	149	COLOMessage msg;
	150	int ret;
	151
	152	msg = qemu_get_be32(f);
	153	ret = qemu_file_get_error(f);
	154	if (ret < 0) {
	155	error_setg_errno(errp, -ret, "Can't receive COLO message");
	156	return msg;
	157	}
	158	if (msg >= COLO_MESSAGE__MAX) {
	159	error_setg(errp, "%s: Invalid message", __func__);
	160	return msg;
	161	}
	162	trace_colo_receive_message(COLOMessage_lookup[msg]);
	163	return msg;
	164	}
	165
	166	static void colo_receive_check_message(QEMUFile *f, COLOMessage expect_msg,
	167	Error **errp)
	168	{
	169	COLOMessage msg;
	170	Error *local_err = NULL;
	171
	172	msg = colo_receive_message(f, &local_err);
	173	if (local_err) {
	174	error_propagate(errp, local_err);
	175	return;
	176	}
	177	if (msg != expect_msg) {
	178	error_setg(errp, "Unexpected COLO message %d, expected %d",
	179	msg, expect_msg);
	180	}
	181	}
	182
4291d372 HZ	183	static uint64_t colo_receive_message_value(QEMUFile *f, uint32_t expect_msg,
	184	Error **errp)
	185	{
	186	Error *local_err = NULL;
	187	uint64_t value;
	188	int ret;
	189
	190	colo_receive_check_message(f, expect_msg, &local_err);
	191	if (local_err) {
	192	error_propagate(errp, local_err);
	193	return 0;
	194	}
	195
	196	value = qemu_get_be64(f);
	197	ret = qemu_file_get_error(f);
	198	if (ret < 0) {
	199	error_setg_errno(errp, -ret, "Failed to get value for COLO message: %s",
	200	COLOMessage_lookup[expect_msg]);
	201	}
	202	return value;
	203	}
	204
a91246c9 HZ	205	static int colo_do_checkpoint_transaction(MigrationState *s,
	206	QIOChannelBuffer *bioc,
	207	QEMUFile *fb)
4f97558e HZ	208	{
4f97558e HZ	209	Error *local_err = NULL;
a91246c9	210	int ret = -1;
4f97558e HZ	211
	212	colo_send_message(s->to_dst_file, COLO_MESSAGE_CHECKPOINT_REQUEST,
	213	&local_err);
	214	if (local_err) {
	215	goto out;
	216	}
	217
	218	colo_receive_check_message(s->rp_state.from_dst_file,
	219	COLO_MESSAGE_CHECKPOINT_REPLY, &local_err);
	220	if (local_err) {
	221	goto out;
	222	}
a91246c9 HZ	223	/* Reset channel-buffer directly */
	224	qio_channel_io_seek(QIO_CHANNEL(bioc), 0, 0, NULL);
	225	bioc->usage = 0;
4f97558e	226
a91246c9	227	qemu_mutex_lock_iothread();
b3f7f0c5 HZ	228	if (failover_get_state() != FAILOVER_STATUS_NONE) {
	229	qemu_mutex_unlock_iothread();
	230	goto out;
	231	}
a91246c9 HZ	232	vm_stop_force_state(RUN_STATE_COLO);
	233	qemu_mutex_unlock_iothread();
	234	trace_colo_vm_state_change("run", "stop");
b3f7f0c5 HZ	235	/*
	236	* Failover request bh could be called after vm_stop_force_state(),
	237	* So we need check failover_request_is_active() again.
	238	*/
	239	if (failover_get_state() != FAILOVER_STATUS_NONE) {
	240	goto out;
	241	}
a91246c9 HZ	242
	243	/* Disable block migration */
	244	s->params.blk = 0;
	245	s->params.shared = 0;
	246	qemu_savevm_state_header(fb);
	247	qemu_savevm_state_begin(fb, &s->params);
	248	qemu_mutex_lock_iothread();
	249	qemu_savevm_state_complete_precopy(fb, false);
	250	qemu_mutex_unlock_iothread();
	251
	252	qemu_fflush(fb);
4f97558e HZ	253
	254	colo_send_message(s->to_dst_file, COLO_MESSAGE_VMSTATE_SEND, &local_err);
	255	if (local_err) {
	256	goto out;
	257	}
a91246c9 HZ	258	/*
	259	* We need the size of the VMstate data in Secondary side,
	260	* With which we can decide how much data should be read.
	261	*/
	262	colo_send_message_value(s->to_dst_file, COLO_MESSAGE_VMSTATE_SIZE,
	263	bioc->usage, &local_err);
	264	if (local_err) {
	265	goto out;
	266	}
4f97558e	267
a91246c9 HZ	268	qemu_put_buffer(s->to_dst_file, bioc->data, bioc->usage);
	269	qemu_fflush(s->to_dst_file);
	270	ret = qemu_file_get_error(s->to_dst_file);
	271	if (ret < 0) {
	272	goto out;
	273	}
4f97558e HZ	274
	275	colo_receive_check_message(s->rp_state.from_dst_file,
	276	COLO_MESSAGE_VMSTATE_RECEIVED, &local_err);
	277	if (local_err) {
	278	goto out;
	279	}
	280
	281	colo_receive_check_message(s->rp_state.from_dst_file,
	282	COLO_MESSAGE_VMSTATE_LOADED, &local_err);
	283	if (local_err) {
	284	goto out;
	285	}
	286
a91246c9 HZ	287	ret = 0;
	288
	289	qemu_mutex_lock_iothread();
	290	vm_start();
	291	qemu_mutex_unlock_iothread();
	292	trace_colo_vm_state_change("stop", "run");
4f97558e	293
4f97558e HZ	294	out:
	295	if (local_err) {
	296	error_report_err(local_err);
	297	}
a91246c9	298	return ret;
4f97558e HZ	299	}
4f97558e HZ	300
0b827d5e HZ	301	static void colo_process_checkpoint(MigrationState *s)
0b827d5e HZ	302	{
a91246c9 HZ	303	QIOChannelBuffer *bioc;
a91246c9 HZ	304	QEMUFile *fb = NULL;
18cc23d7	305	int64_t current_time, checkpoint_time = qemu_clock_get_ms(QEMU_CLOCK_HOST);
4f97558e HZ	306	Error *local_err = NULL;
	307	int ret;
	308
aef06085 HZ	309	failover_init_state();
aef06085 HZ	310
56ba83d2 HZ	311	s->rp_state.from_dst_file = qemu_file_get_return_path(s->to_dst_file);
	312	if (!s->rp_state.from_dst_file) {
	313	error_report("Open QEMUFile from_dst_file failed");
	314	goto out;
	315	}
	316
4f97558e HZ	317	/*
	318	* Wait for Secondary finish loading VM states and enter COLO
	319	* restore.
	320	*/
	321	colo_receive_check_message(s->rp_state.from_dst_file,
	322	COLO_MESSAGE_CHECKPOINT_READY, &local_err);
	323	if (local_err) {
	324	goto out;
	325	}
a91246c9 HZ	326	bioc = qio_channel_buffer_new(COLO_BUFFER_BASE_SIZE);
	327	fb = qemu_fopen_channel_output(QIO_CHANNEL(bioc));
	328	object_unref(OBJECT(bioc));
4f97558e	329
0b827d5e HZ	330	qemu_mutex_lock_iothread();
	331	vm_start();
	332	qemu_mutex_unlock_iothread();
	333	trace_colo_vm_state_change("stop", "run");
	334
4f97558e	335	while (s->state == MIGRATION_STATUS_COLO) {
b3f7f0c5 HZ	336	if (failover_get_state() != FAILOVER_STATUS_NONE) {
	337	error_report("failover request");
	338	goto out;
	339	}
	340
18cc23d7 HZ	341	current_time = qemu_clock_get_ms(QEMU_CLOCK_HOST);
	342	if (current_time - checkpoint_time <
	343	s->parameters.x_checkpoint_delay) {
	344	int64_t delay_ms;
	345
	346	delay_ms = s->parameters.x_checkpoint_delay -
	347	(current_time - checkpoint_time);
	348	g_usleep(delay_ms * 1000);
	349	}
a91246c9	350	ret = colo_do_checkpoint_transaction(s, bioc, fb);
4f97558e HZ	351	if (ret < 0) {
	352	goto out;
	353	}
18cc23d7	354	checkpoint_time = qemu_clock_get_ms(QEMU_CLOCK_HOST);
4f97558e	355	}
0b827d5e	356
56ba83d2	357	out:
4f97558e HZ	358	/* Throw the unreported error message after exited from loop */
	359	if (local_err) {
	360	error_report_err(local_err);
	361	}
	362
a91246c9 HZ	363	if (fb) {
	364	qemu_fclose(fb);
	365	}
	366
56ba83d2 HZ	367	if (s->rp_state.from_dst_file) {
	368	qemu_fclose(s->rp_state.from_dst_file);
	369	}
0b827d5e HZ	370	}
	371
	372	void migrate_start_colo_process(MigrationState *s)
	373	{
	374	qemu_mutex_unlock_iothread();
	375	migrate_set_state(&s->state, MIGRATION_STATUS_ACTIVE,
	376	MIGRATION_STATUS_COLO);
	377	colo_process_checkpoint(s);
	378	qemu_mutex_lock_iothread();
	379	}
25d0c16f	380
4f97558e HZ	381	static void colo_wait_handle_message(QEMUFile f, int checkpoint_request,
	382	Error **errp)
	383	{
	384	COLOMessage msg;
	385	Error *local_err = NULL;
	386
	387	msg = colo_receive_message(f, &local_err);
	388	if (local_err) {
	389	error_propagate(errp, local_err);
	390	return;
	391	}
	392
	393	switch (msg) {
	394	case COLO_MESSAGE_CHECKPOINT_REQUEST:
	395	*checkpoint_request = 1;
	396	break;
	397	default:
	398	*checkpoint_request = 0;
	399	error_setg(errp, "Got unknown COLO message: %d", msg);
	400	break;
	401	}
	402	}
	403
25d0c16f HZ	404	void colo_process_incoming_thread(void opaque)
	405	{
	406	MigrationIncomingState *mis = opaque;
4291d372 HZ	407	QEMUFile *fb = NULL;
	408	QIOChannelBuffer bioc = NULL; / Cache incoming device state */
	409	uint64_t total_size;
	410	uint64_t value;
4f97558e	411	Error *local_err = NULL;
25d0c16f HZ	412
	413	migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE,
	414	MIGRATION_STATUS_COLO);
	415
aef06085 HZ	416	failover_init_state();
aef06085 HZ	417
56ba83d2 HZ	418	mis->to_src_file = qemu_file_get_return_path(mis->from_src_file);
	419	if (!mis->to_src_file) {
	420	error_report("COLO incoming thread: Open QEMUFile to_src_file failed");
	421	goto out;
	422	}
	423	/*
	424	* Note: the communication between Primary side and Secondary side
	425	* should be sequential, we set the fd to unblocked in migration incoming
	426	* coroutine, and here we are in the COLO incoming thread, so it is ok to
	427	* set the fd back to blocked.
	428	*/
	429	qemu_file_set_blocking(mis->from_src_file, true);
	430
4291d372 HZ	431	bioc = qio_channel_buffer_new(COLO_BUFFER_BASE_SIZE);
	432	fb = qemu_fopen_channel_input(QIO_CHANNEL(bioc));
	433	object_unref(OBJECT(bioc));
	434
4f97558e HZ	435	colo_send_message(mis->to_src_file, COLO_MESSAGE_CHECKPOINT_READY,
	436	&local_err);
	437	if (local_err) {
	438	goto out;
	439	}
	440
	441	while (mis->state == MIGRATION_STATUS_COLO) {
	442	int request;
	443
	444	colo_wait_handle_message(mis->from_src_file, &request, &local_err);
	445	if (local_err) {
	446	goto out;
	447	}
	448	assert(request);
9d2db376 HZ	449	if (failover_get_state() != FAILOVER_STATUS_NONE) {
	450	error_report("failover request");
	451	goto out;
	452	}
	453
4f97558e HZ	454	/* FIXME: This is unnecessary for periodic checkpoint mode */
	455	colo_send_message(mis->to_src_file, COLO_MESSAGE_CHECKPOINT_REPLY,
	456	&local_err);
	457	if (local_err) {
	458	goto out;
	459	}
	460
	461	colo_receive_check_message(mis->from_src_file,
	462	COLO_MESSAGE_VMSTATE_SEND, &local_err);
	463	if (local_err) {
	464	goto out;
	465	}
	466
4291d372 HZ	467	value = colo_receive_message_value(mis->from_src_file,
	468	COLO_MESSAGE_VMSTATE_SIZE, &local_err);
	469	if (local_err) {
	470	goto out;
	471	}
	472
	473	/*
	474	* Read VM device state data into channel buffer,
	475	* It's better to re-use the memory allocated.
	476	* Here we need to handle the channel buffer directly.
	477	*/
	478	if (value > bioc->capacity) {
	479	bioc->capacity = value;
	480	bioc->data = g_realloc(bioc->data, bioc->capacity);
	481	}
	482	total_size = qemu_get_buffer(mis->from_src_file, bioc->data, value);
	483	if (total_size != value) {
	484	error_report("Got %" PRIu64 " VMState data, less than expected"
	485	" %" PRIu64, total_size, value);
	486	goto out;
	487	}
	488	bioc->usage = total_size;
	489	qio_channel_io_seek(QIO_CHANNEL(bioc), 0, 0, NULL);
4f97558e HZ	490
	491	colo_send_message(mis->to_src_file, COLO_MESSAGE_VMSTATE_RECEIVED,
	492	&local_err);
	493	if (local_err) {
	494	goto out;
	495	}
	496
4291d372 HZ	497	qemu_mutex_lock_iothread();
	498	qemu_system_reset(VMRESET_SILENT);
	499	if (qemu_loadvm_state(fb) < 0) {
	500	error_report("COLO: loadvm failed");
	501	qemu_mutex_unlock_iothread();
	502	goto out;
	503	}
	504	qemu_mutex_unlock_iothread();
4f97558e HZ	505
	506	colo_send_message(mis->to_src_file, COLO_MESSAGE_VMSTATE_LOADED,
	507	&local_err);
	508	if (local_err) {
	509	goto out;
	510	}
	511	}
25d0c16f	512
56ba83d2	513	out:
4f97558e HZ	514	/* Throw the unreported error message after exited from loop */
	515	if (local_err) {
	516	error_report_err(local_err);
	517	}
	518
4291d372 HZ	519	if (fb) {
	520	qemu_fclose(fb);
	521	}
	522
56ba83d2 HZ	523	if (mis->to_src_file) {
	524	qemu_fclose(mis->to_src_file);
	525	}
25d0c16f HZ	526	migration_incoming_exit_colo();
	527
	528	return NULL;
	529	}