balloon.c

   1 /*
   2  * Generic Balloon handlers and management
   3  *
   4  * Copyright (c) 2003-2008 Fabrice Bellard
   5  * Copyright (C) 2011 Red Hat, Inc.
   6  * Copyright (C) 2011 Amit Shah <amit.shah@redhat.com>
   7  *
   8  * Permission is hereby granted, free of charge, to any person obtaining a copy
   9  * of this software and associated documentation files (the "Software"), to deal
  10  * in the Software without restriction, including without limitation the rights
  11  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  12  * copies of the Software, and to permit persons to whom the Software is
  13  * furnished to do so, subject to the following conditions:
  14  *
  15  * The above copyright notice and this permission notice shall be included in
  16  * all copies or substantial portions of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  21  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  22  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  23  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  24  * THE SOFTWARE.
  25  */
  26
  27 #include "monitor.h"
  28 #include "qjson.h"
  29 #include "qint.h"
  30 #include "cpu-common.h"
  31 #include "kvm.h"
  32 #include "balloon.h"
  33 #include "trace.h"
  34
  35 static QEMUBalloonEvent *balloon_event_fn;
  36 static QEMUBalloonStatus *balloon_stat_fn;
  37 static void *balloon_opaque;
  38
  39 void qemu_add_balloon_handler(QEMUBalloonEvent *event_func,
  40                               QEMUBalloonStatus *stat_func, void *opaque)
  41 {
  42     balloon_event_fn = event_func;
  43     balloon_stat_fn = stat_func;
  44     balloon_opaque = opaque;
  45 }
  46
  47 static int qemu_balloon(ram_addr_t target)
  48 {
  49     if (!balloon_event_fn) {
  50         return 0;
  51     }
  52     trace_balloon_event(balloon_opaque, target);
  53     balloon_event_fn(balloon_opaque, target);
  54     return 1;
  55 }
  56
  57 static int qemu_balloon_status(MonitorCompletion cb, void *opaque)
  58 {
  59     if (!balloon_stat_fn) {
  60         return 0;
  61     }
  62     balloon_stat_fn(balloon_opaque, cb, opaque);
  63     return 1;
  64 }
  65
  66 static void print_balloon_stat(const char *key, QObject *obj, void *opaque)
  67 {
  68     Monitor *mon = opaque;
  69
  70     if (strcmp(key, "actual")) {
  71         monitor_printf(mon, ",%s=%" PRId64, key,
  72                        qint_get_int(qobject_to_qint(obj)));
  73     }
  74 }
  75
  76 void monitor_print_balloon(Monitor *mon, const QObject *data)
  77 {
  78     QDict *qdict;
  79
  80     qdict = qobject_to_qdict(data);
  81     if (!qdict_haskey(qdict, "actual")) {
  82         return;
  83     }
  84     monitor_printf(mon, "balloon: actual=%" PRId64,
  85                    qdict_get_int(qdict, "actual") >> 20);
  86     qdict_iter(qdict, print_balloon_stat, mon);
  87     monitor_printf(mon, "\n");
  88 }
  89
  90 /**
  91  * do_info_balloon(): Balloon information
  92  *
  93  * Make an asynchronous request for balloon info.  When the request completes
  94  * a QDict will be returned according to the following specification:
  95  *
  96  * - "actual": current balloon value in bytes
  97  * The following fields may or may not be present:
  98  * - "mem_swapped_in": Amount of memory swapped in (bytes)
  99  * - "mem_swapped_out": Amount of memory swapped out (bytes)
 100  * - "major_page_faults": Number of major faults
 101  * - "minor_page_faults": Number of minor faults
 102  * - "free_mem": Total amount of free and unused memory (bytes)
 103  * - "total_mem": Total amount of available memory (bytes)
 104  *
 105  * Example:
 106  *
 107  * { "actual": 1073741824, "mem_swapped_in": 0, "mem_swapped_out": 0,
 108  *   "major_page_faults": 142, "minor_page_faults": 239245,
 109  *   "free_mem": 1014185984, "total_mem": 1044668416 }
 110  */
 111 int do_info_balloon(Monitor *mon, MonitorCompletion cb, void *opaque)
 112 {
 113     int ret;
 114
 115     if (kvm_enabled() && !kvm_has_sync_mmu()) {
 116         qerror_report(QERR_KVM_MISSING_CAP, "synchronous MMU", "balloon");
 117         return -1;
 118     }
 119
 120     ret = qemu_balloon_status(cb, opaque);
 121     if (!ret) {
 122         qerror_report(QERR_DEVICE_NOT_ACTIVE, "balloon");
 123         return -1;
 124     }
 125
 126     return 0;
 127 }
 128
 129 /**
 130  * do_balloon(): Request VM to change its memory allocation
 131  */
 132 int do_balloon(Monitor *mon, const QDict *params,
 133                MonitorCompletion cb, void *opaque)
 134 {
 135     int ret;
 136
 137     if (kvm_enabled() && !kvm_has_sync_mmu()) {
 138         qerror_report(QERR_KVM_MISSING_CAP, "synchronous MMU", "balloon");
 139         return -1;
 140     }
 141
 142     ret = qemu_balloon(qdict_get_int(params, "value"));
 143     if (ret == 0) {
 144         qerror_report(QERR_DEVICE_NOT_ACTIVE, "balloon");
 145         return -1;
 146     }
 147
 148     cb(opaque, NULL);
 149     return 0;
 150 }