Archipelago » qemu

/*

 * Generic Balloon handlers and management

 *

 * Copyright (c) 2003-2008 Fabrice Bellard

 * Copyright (C) 2011 Red Hat, Inc.

 * Copyright (C) 2011 Amit Shah <amit.shah@redhat.com>

 *

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to deal

 * in the Software without restriction, including without limitation the rights

 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

 * copies of the Software, and to permit persons to whom the Software is

 * furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL

 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

 * THE SOFTWARE.

 */

#include "monitor.h"

#include "qjson.h"

#include "qint.h"

#include "cpu-common.h"

#include "kvm.h"

#include "balloon.h"

#include "trace.h"

static QEMUBalloonEvent *balloon_event_fn;

static QEMUBalloonStatus *balloon_stat_fn;

static void *balloon_opaque;

int qemu_add_balloon_handler(QEMUBalloonEvent *event_func,

                             QEMUBalloonStatus *stat_func, void *opaque)

{

    if (balloon_event_fn || balloon_stat_fn || balloon_opaque) {

        /* We're already registered one balloon handler.  How many can

         * a guest really have?

         */

        error_report("Another balloon device already registered");

        return -1;

    }

    balloon_event_fn = event_func;

    balloon_stat_fn = stat_func;

    balloon_opaque = opaque;

    return 0;

}

void qemu_remove_balloon_handler(void *opaque)

{

    if (balloon_opaque != opaque) {

        return;

    }

    balloon_event_fn = NULL;

    balloon_stat_fn = NULL;

    balloon_opaque = NULL;

}

static int qemu_balloon(ram_addr_t target)

{

    if (!balloon_event_fn) {

        return 0;

    }

    trace_balloon_event(balloon_opaque, target);

    balloon_event_fn(balloon_opaque, target);

    return 1;

}

static int qemu_balloon_status(MonitorCompletion cb, void *opaque)

{

    if (!balloon_stat_fn) {

        return 0;

    }

    balloon_stat_fn(balloon_opaque, cb, opaque);

    return 1;

}

static void print_balloon_stat(const char *key, QObject *obj, void *opaque)

{

    Monitor *mon = opaque;

    if (strcmp(key, "actual")) {

        monitor_printf(mon, ",%s=%" PRId64, key,

                       qint_get_int(qobject_to_qint(obj)));

    }

}

void monitor_print_balloon(Monitor *mon, const QObject *data)

{

    QDict *qdict;

    qdict = qobject_to_qdict(data);

    if (!qdict_haskey(qdict, "actual")) {

        return;

    }

    monitor_printf(mon, "balloon: actual=%" PRId64,

                   qdict_get_int(qdict, "actual") >> 20);

    qdict_iter(qdict, print_balloon_stat, mon);

    monitor_printf(mon, "\n");

}

/**

 * do_info_balloon(): Balloon information

 *

 * Make an asynchronous request for balloon info.  When the request completes

 * a QDict will be returned according to the following specification:

 *

 * - "actual": current balloon value in bytes

 * The following fields may or may not be present:

 * - "mem_swapped_in": Amount of memory swapped in (bytes)

 * - "mem_swapped_out": Amount of memory swapped out (bytes)

 * - "major_page_faults": Number of major faults

 * - "minor_page_faults": Number of minor faults

 * - "free_mem": Total amount of free and unused memory (bytes)

 * - "total_mem": Total amount of available memory (bytes)

 *

 * Example:

 *

 * { "actual": 1073741824, "mem_swapped_in": 0, "mem_swapped_out": 0,

 *   "major_page_faults": 142, "minor_page_faults": 239245,

 *   "free_mem": 1014185984, "total_mem": 1044668416 }

 */

int do_info_balloon(Monitor *mon, MonitorCompletion cb, void *opaque)

{

    int ret;

    if (kvm_enabled() && !kvm_has_sync_mmu()) {

        qerror_report(QERR_KVM_MISSING_CAP, "synchronous MMU", "balloon");

        return -1;

    }

    ret = qemu_balloon_status(cb, opaque);

    if (!ret) {

        qerror_report(QERR_DEVICE_NOT_ACTIVE, "balloon");

        return -1;

    }

    return 0;

}

/**

 * do_balloon(): Request VM to change its memory allocation

 */

int do_balloon(Monitor *mon, const QDict *params,

               MonitorCompletion cb, void *opaque)

{

    int64_t target;

    int ret;

    if (kvm_enabled() && !kvm_has_sync_mmu()) {

        qerror_report(QERR_KVM_MISSING_CAP, "synchronous MMU", "balloon");

        return -1;

    }

    target = qdict_get_int(params, "value");

    if (target <= 0) {

        qerror_report(QERR_INVALID_PARAMETER_VALUE, "target", "a size");

        return -1;

    }

    ret = qemu_balloon(target);

    if (ret == 0) {

        qerror_report(QERR_DEVICE_NOT_ACTIVE, "balloon");

        return -1;

    }

    cb(opaque, NULL);

    return 0;

}