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 "monitor.h"
  26 #include "qjson.h"
  27 #include "qint.h"
  28 #include "cpu-common.h"
  29 #include "kvm.h"
  30 #include "balloon.h"
  31 #include "trace.h"
  32
  33
  34 static QEMUBalloonEvent *balloon_event_fn;
  35 static void *balloon_opaque;
  36
  37 void qemu_add_balloon_handler(QEMUBalloonEvent *func, void *opaque)
  38 {
  39     balloon_event_fn = func;
  40     balloon_opaque = opaque;
  41 }
  42
  43 static int qemu_balloon(ram_addr_t target, MonitorCompletion cb, void *opaque)
  44 {
  45     if (balloon_event_fn) {
  46         trace_balloon_event(balloon_opaque, target);
  47         balloon_event_fn(balloon_opaque, target, cb, opaque);
  48         return 1;
  49     } else {
  50         return 0;
  51     }
  52 }
  53
  54 static int qemu_balloon_status(MonitorCompletion cb, void *opaque)
  55 {
  56     if (balloon_event_fn) {
  57         balloon_event_fn(balloon_opaque, 0, cb, opaque);
  58         return 1;
  59     } else {
  60         return 0;
  61     }
  62 }
  63
  64 static void print_balloon_stat(const char *key, QObject *obj, void *opaque)
  65 {
  66     Monitor *mon = opaque;
  67
  68     if (strcmp(key, "actual")) {
  69         monitor_printf(mon, ",%s=%" PRId64, key,
  70                        qint_get_int(qobject_to_qint(obj)));
  71     }
  72 }
  73
  74 void monitor_print_balloon(Monitor *mon, const QObject *data)
  75 {
  76     QDict *qdict;
  77
  78     qdict = qobject_to_qdict(data);
  79     if (!qdict_haskey(qdict, "actual")) {
  80         return;
  81     }
  82     monitor_printf(mon, "balloon: actual=%" PRId64,
  83                    qdict_get_int(qdict, "actual") >> 20);
  84     qdict_iter(qdict, print_balloon_stat, mon);
  85     monitor_printf(mon, "\n");
  86 }
  87
  88 /**
  89  * do_info_balloon(): Balloon information
  90  *
  91  * Make an asynchronous request for balloon info.  When the request completes
  92  * a QDict will be returned according to the following specification:
  93  *
  94  * - "actual": current balloon value in bytes
  95  * The following fields may or may not be present:
  96  * - "mem_swapped_in": Amount of memory swapped in (bytes)
  97  * - "mem_swapped_out": Amount of memory swapped out (bytes)
  98  * - "major_page_faults": Number of major faults
  99  * - "minor_page_faults": Number of minor faults
 100  * - "free_mem": Total amount of free and unused memory (bytes)
 101  * - "total_mem": Total amount of available memory (bytes)
 102  *
 103  * Example:
 104  *
 105  * { "actual": 1073741824, "mem_swapped_in": 0, "mem_swapped_out": 0,
 106  *   "major_page_faults": 142, "minor_page_faults": 239245,
 107  *   "free_mem": 1014185984, "total_mem": 1044668416 }
 108  */
 109 int do_info_balloon(Monitor *mon, MonitorCompletion cb, void *opaque)
 110 {
 111     int ret;
 112
 113     if (kvm_enabled() && !kvm_has_sync_mmu()) {
 114         qerror_report(QERR_KVM_MISSING_CAP, "synchronous MMU", "balloon");
 115         return -1;
 116     }
 117
 118     ret = qemu_balloon_status(cb, opaque);
 119     if (!ret) {
 120         qerror_report(QERR_DEVICE_NOT_ACTIVE, "balloon");
 121         return -1;
 122     }
 123
 124     return 0;
 125 }
 126
 127 /**
 128  * do_balloon(): Request VM to change its memory allocation
 129  */
 130 int do_balloon(Monitor *mon, const QDict *params,
 131                MonitorCompletion cb, void *opaque)
 132 {
 133     int ret;
 134
 135     if (kvm_enabled() && !kvm_has_sync_mmu()) {
 136         qerror_report(QERR_KVM_MISSING_CAP, "synchronous MMU", "balloon");
 137         return -1;
 138     }
 139
 140     ret = qemu_balloon(qdict_get_int(params, "value"), cb, opaque);
 141     if (ret == 0) {
 142         qerror_report(QERR_DEVICE_NOT_ACTIVE, "balloon");
 143         return -1;
 144     }
 145
 146     cb(opaque, NULL);
 147     return 0;
 148 }