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 QEMUBalloonStatus *balloon_stat_fn;
  36 static void *balloon_opaque;
  37
  38 void qemu_add_balloon_handler(QEMUBalloonEvent *event_func,
  39                               QEMUBalloonStatus *stat_func, void *opaque)
  40 {
  41     balloon_event_fn = event_func;
  42     balloon_stat_fn = stat_func;
  43     balloon_opaque = opaque;
  44 }
  45
  46 static int qemu_balloon(ram_addr_t target)
  47 {
  48     if (!balloon_event_fn) {
  49         return 0;
  50     }
  51     trace_balloon_event(balloon_opaque, target);
  52     balloon_event_fn(balloon_opaque, target);
  53     return 1;
  54 }
  55
  56 static int qemu_balloon_status(MonitorCompletion cb, void *opaque)
  57 {
  58     if (!balloon_stat_fn) {
  59         return 0;
  60     }
  61     balloon_stat_fn(balloon_opaque, cb, opaque);
  62     return 1;
  63 }
  64
  65 static void print_balloon_stat(const char *key, QObject *obj, void *opaque)
  66 {
  67     Monitor *mon = opaque;
  68
  69     if (strcmp(key, "actual")) {
  70         monitor_printf(mon, ",%s=%" PRId64, key,
  71                        qint_get_int(qobject_to_qint(obj)));
  72     }
  73 }
  74
  75 void monitor_print_balloon(Monitor *mon, const QObject *data)
  76 {
  77     QDict *qdict;
  78
  79     qdict = qobject_to_qdict(data);
  80     if (!qdict_haskey(qdict, "actual")) {
  81         return;
  82     }
  83     monitor_printf(mon, "balloon: actual=%" PRId64,
  84                    qdict_get_int(qdict, "actual") >> 20);
  85     qdict_iter(qdict, print_balloon_stat, mon);
  86     monitor_printf(mon, "\n");
  87 }
  88
  89 /**
  90  * do_info_balloon(): Balloon information
  91  *
  92  * Make an asynchronous request for balloon info.  When the request completes
  93  * a QDict will be returned according to the following specification:
  94  *
  95  * - "actual": current balloon value in bytes
  96  * The following fields may or may not be present:
  97  * - "mem_swapped_in": Amount of memory swapped in (bytes)
  98  * - "mem_swapped_out": Amount of memory swapped out (bytes)
  99  * - "major_page_faults": Number of major faults
 100  * - "minor_page_faults": Number of minor faults
 101  * - "free_mem": Total amount of free and unused memory (bytes)
 102  * - "total_mem": Total amount of available memory (bytes)
 103  *
 104  * Example:
 105  *
 106  * { "actual": 1073741824, "mem_swapped_in": 0, "mem_swapped_out": 0,
 107  *   "major_page_faults": 142, "minor_page_faults": 239245,
 108  *   "free_mem": 1014185984, "total_mem": 1044668416 }
 109  */
 110 int do_info_balloon(Monitor *mon, MonitorCompletion cb, void *opaque)
 111 {
 112     int ret;
 113
 114     if (kvm_enabled() && !kvm_has_sync_mmu()) {
 115         qerror_report(QERR_KVM_MISSING_CAP, "synchronous MMU", "balloon");
 116         return -1;
 117     }
 118
 119     ret = qemu_balloon_status(cb, opaque);
 120     if (!ret) {
 121         qerror_report(QERR_DEVICE_NOT_ACTIVE, "balloon");
 122         return -1;
 123     }
 124
 125     return 0;
 126 }
 127
 128 /**
 129  * do_balloon(): Request VM to change its memory allocation
 130  */
 131 int do_balloon(Monitor *mon, const QDict *params,
 132                MonitorCompletion cb, void *opaque)
 133 {
 134     int ret;
 135
 136     if (kvm_enabled() && !kvm_has_sync_mmu()) {
 137         qerror_report(QERR_KVM_MISSING_CAP, "synchronous MMU", "balloon");
 138         return -1;
 139     }
 140
 141     ret = qemu_balloon(qdict_get_int(params, "value"));
 142     if (ret == 0) {
 143         qerror_report(QERR_DEVICE_NOT_ACTIVE, "balloon");
 144         return -1;
 145     }
 146
 147     cb(opaque, NULL);
 148     return 0;
 149 }