2 * Generic Balloon handlers and management
4 * Copyright (c) 2003-2008 Fabrice Bellard
5 * Copyright (C) 2011 Red Hat, Inc.
6 * Copyright (C) 2011 Amit Shah <amit.shah@redhat.com>
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:
15 * The above copyright notice and this permission notice shall be included in
16 * all copies or substantial portions of the Software.
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
30 #include "cpu-common.h"
35 static QEMUBalloonEvent *balloon_event_fn;
36 static QEMUBalloonStatus *balloon_stat_fn;
37 static void *balloon_opaque;
39 int qemu_add_balloon_handler(QEMUBalloonEvent *event_func,
40 QEMUBalloonStatus *stat_func, void *opaque)
42 if (balloon_event_fn || balloon_stat_fn || balloon_opaque) {
43 /* We're already registered one balloon handler. How many can
44 * a guest really have?
46 error_report("Another balloon device already registered");
49 balloon_event_fn = event_func;
50 balloon_stat_fn = stat_func;
51 balloon_opaque = opaque;
55 void qemu_remove_balloon_handler(void *opaque)
57 if (balloon_opaque != opaque) {
60 balloon_event_fn = NULL;
61 balloon_stat_fn = NULL;
62 balloon_opaque = NULL;
65 static int qemu_balloon(ram_addr_t target)
67 if (!balloon_event_fn) {
70 trace_balloon_event(balloon_opaque, target);
71 balloon_event_fn(balloon_opaque, target);
75 static int qemu_balloon_status(MonitorCompletion cb, void *opaque)
77 if (!balloon_stat_fn) {
80 balloon_stat_fn(balloon_opaque, cb, opaque);
84 static void print_balloon_stat(const char *key, QObject *obj, void *opaque)
86 Monitor *mon = opaque;
88 if (strcmp(key, "actual")) {
89 monitor_printf(mon, ",%s=%" PRId64, key,
90 qint_get_int(qobject_to_qint(obj)));
94 void monitor_print_balloon(Monitor *mon, const QObject *data)
98 qdict = qobject_to_qdict(data);
99 if (!qdict_haskey(qdict, "actual")) {
102 monitor_printf(mon, "balloon: actual=%" PRId64,
103 qdict_get_int(qdict, "actual") >> 20);
104 qdict_iter(qdict, print_balloon_stat, mon);
105 monitor_printf(mon, "\n");
109 * do_info_balloon(): Balloon information
111 * Make an asynchronous request for balloon info. When the request completes
112 * a QDict will be returned according to the following specification:
114 * - "actual": current balloon value in bytes
115 * The following fields may or may not be present:
116 * - "mem_swapped_in": Amount of memory swapped in (bytes)
117 * - "mem_swapped_out": Amount of memory swapped out (bytes)
118 * - "major_page_faults": Number of major faults
119 * - "minor_page_faults": Number of minor faults
120 * - "free_mem": Total amount of free and unused memory (bytes)
121 * - "total_mem": Total amount of available memory (bytes)
125 * { "actual": 1073741824, "mem_swapped_in": 0, "mem_swapped_out": 0,
126 * "major_page_faults": 142, "minor_page_faults": 239245,
127 * "free_mem": 1014185984, "total_mem": 1044668416 }
129 int do_info_balloon(Monitor *mon, MonitorCompletion cb, void *opaque)
133 if (kvm_enabled() && !kvm_has_sync_mmu()) {
134 qerror_report(QERR_KVM_MISSING_CAP, "synchronous MMU", "balloon");
138 ret = qemu_balloon_status(cb, opaque);
140 qerror_report(QERR_DEVICE_NOT_ACTIVE, "balloon");
148 * do_balloon(): Request VM to change its memory allocation
150 int do_balloon(Monitor *mon, const QDict *params,
151 MonitorCompletion cb, void *opaque)
156 if (kvm_enabled() && !kvm_has_sync_mmu()) {
157 qerror_report(QERR_KVM_MISSING_CAP, "synchronous MMU", "balloon");
161 target = qdict_get_int(params, "value");
163 qerror_report(QERR_INVALID_PARAMETER_VALUE, "target", "a size");
166 ret = qemu_balloon(target);
168 qerror_report(QERR_DEVICE_NOT_ACTIVE, "balloon");