balloon.c

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