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/monitor.h"

#include "exec/cpu-common.h"

#include "sysemu/kvm.h"

#include "sysemu/balloon.h"

#include "trace.h"

#include "qmp-commands.h"

#include "qapi/qmp/qjson.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(BalloonInfo *info)

{

    if (!balloon_stat_fn) {

        return 0;

    }

    balloon_stat_fn(balloon_opaque, info);

    return 1;

}

void qemu_balloon_changed(int64_t actual)

{

    QObject *data;

    data = qobject_from_jsonf("{ 'actual': %" PRId64 " }",

                              actual);

    monitor_protocol_event(QEVENT_BALLOON_CHANGE, data);

    qobject_decref(data);

}

BalloonInfo *qmp_query_balloon(Error **errp)

{

    BalloonInfo *info;

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

        error_set(errp, QERR_KVM_MISSING_CAP, "synchronous MMU", "balloon");

        return NULL;

    }

    info = g_malloc0(sizeof(*info));

    if (qemu_balloon_status(info) == 0) {

        error_set(errp, QERR_DEVICE_NOT_ACTIVE, "balloon");

        qapi_free_BalloonInfo(info);

        return NULL;

    }

    return info;

}

void qmp_balloon(int64_t value, Error **errp)

{

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

        error_set(errp, QERR_KVM_MISSING_CAP, "synchronous MMU", "balloon");

        return;

    }

    if (value <= 0) {

        error_set(errp, QERR_INVALID_PARAMETER_VALUE, "target", "a size");

        return;

    }

    if (qemu_balloon(value) == 0) {

        error_set(errp, QERR_DEVICE_NOT_ACTIVE, "balloon");

    }

}