blob: 9319879838589402478dbcc9d17be8a3a30f67a5 [file] [log] [blame]
Paolo Bonzini28c28972010-04-01 19:57:12 +02001/*
Amit Shah73428a82011-07-20 13:35:30 +05302 * Generic Balloon handlers and management
Paolo Bonzini28c28972010-04-01 19:57:12 +02003 *
4 * Copyright (c) 2003-2008 Fabrice Bellard
Amit Shah73428a82011-07-20 13:35:30 +05305 * Copyright (C) 2011 Red Hat, Inc.
6 * Copyright (C) 2011 Amit Shah <amit.shah@redhat.com>
Paolo Bonzini28c28972010-04-01 19:57:12 +02007 *
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
Peter Maydelld38ea872016-01-29 17:50:05 +000027#include "qemu/osdep.h"
Markus Armbrustera0b1a662015-03-17 18:16:21 +010028#include "qemu-common.h"
Alex Williamson01ccbec2018-08-17 09:27:15 -060029#include "qemu/atomic.h"
Paolo Bonzini022c62c2012-12-17 18:19:49 +010030#include "exec/cpu-common.h"
Paolo Bonzini9c17d612012-12-17 18:20:04 +010031#include "sysemu/kvm.h"
32#include "sysemu/balloon.h"
Daniel P. Berrange0ab8ed12017-01-25 16:14:15 +000033#include "trace-root.h"
Markus Armbrustere688df62018-02-01 12:18:31 +010034#include "qapi/error.h"
Markus Armbruster112ed242018-02-26 17:13:27 -060035#include "qapi/qapi-commands-misc.h"
Markus Armbrustercc7a8ea2015-03-17 17:22:46 +010036#include "qapi/qmp/qerror.h"
Paolo Bonzini28c28972010-04-01 19:57:12 +020037
Amit Shah0a2a30d2011-07-20 13:08:46 +053038static QEMUBalloonEvent *balloon_event_fn;
Amit Shah30fb2ca2011-07-20 13:30:56 +053039static QEMUBalloonStatus *balloon_stat_fn;
Amit Shah0a2a30d2011-07-20 13:08:46 +053040static void *balloon_opaque;
Alex Williamson01ccbec2018-08-17 09:27:15 -060041static int balloon_inhibit_count;
Dr. David Alan Gilbert371ff5a2015-11-05 18:11:23 +000042
43bool qemu_balloon_is_inhibited(void)
44{
Alex Williamson01ccbec2018-08-17 09:27:15 -060045 return atomic_read(&balloon_inhibit_count) > 0;
Dr. David Alan Gilbert371ff5a2015-11-05 18:11:23 +000046}
47
48void qemu_balloon_inhibit(bool state)
49{
Alex Williamson01ccbec2018-08-17 09:27:15 -060050 if (state) {
51 atomic_inc(&balloon_inhibit_count);
52 } else {
53 atomic_dec(&balloon_inhibit_count);
54 }
55
56 assert(atomic_read(&balloon_inhibit_count) >= 0);
Dr. David Alan Gilbert371ff5a2015-11-05 18:11:23 +000057}
Paolo Bonzini28c28972010-04-01 19:57:12 +020058
Eric Blake438e8282015-02-10 15:40:30 -070059static bool have_balloon(Error **errp)
Markus Armbruster422e0502015-01-13 17:44:14 +010060{
61 if (kvm_enabled() && !kvm_has_sync_mmu()) {
Markus Armbruster2ad28a02015-01-13 17:50:23 +010062 error_set(errp, ERROR_CLASS_KVM_MISSING_CAP,
63 "Using KVM without synchronous MMU, balloon unavailable");
Markus Armbruster422e0502015-01-13 17:44:14 +010064 return false;
65 }
66 if (!balloon_event_fn) {
Markus Armbruster2ad28a02015-01-13 17:50:23 +010067 error_set(errp, ERROR_CLASS_DEVICE_NOT_ACTIVE,
68 "No balloon device has been activated");
Markus Armbruster422e0502015-01-13 17:44:14 +010069 return false;
70 }
71 return true;
72}
73
Amit Shah6c6ec182011-07-27 12:28:19 +053074int qemu_add_balloon_handler(QEMUBalloonEvent *event_func,
75 QEMUBalloonStatus *stat_func, void *opaque)
Paolo Bonzini28c28972010-04-01 19:57:12 +020076{
Amit Shah6c6ec182011-07-27 12:28:19 +053077 if (balloon_event_fn || balloon_stat_fn || balloon_opaque) {
78 /* We're already registered one balloon handler. How many can
79 * a guest really have?
80 */
Amit Shah6c6ec182011-07-27 12:28:19 +053081 return -1;
82 }
Amit Shah30fb2ca2011-07-20 13:30:56 +053083 balloon_event_fn = event_func;
84 balloon_stat_fn = stat_func;
Amit Shah0a2a30d2011-07-20 13:08:46 +053085 balloon_opaque = opaque;
Amit Shah6c6ec182011-07-27 12:28:19 +053086 return 0;
Paolo Bonzini28c28972010-04-01 19:57:12 +020087}
88
Amit Shah8a7d5522011-09-09 14:30:39 +053089void qemu_remove_balloon_handler(void *opaque)
90{
91 if (balloon_opaque != opaque) {
92 return;
93 }
94 balloon_event_fn = NULL;
95 balloon_stat_fn = NULL;
96 balloon_opaque = NULL;
97}
98
Luiz Capitulino96637bc2011-10-21 11:41:37 -020099BalloonInfo *qmp_query_balloon(Error **errp)
Paolo Bonzini28c28972010-04-01 19:57:12 +0200100{
Luiz Capitulino96637bc2011-10-21 11:41:37 -0200101 BalloonInfo *info;
Paolo Bonzini28c28972010-04-01 19:57:12 +0200102
Eric Blake438e8282015-02-10 15:40:30 -0700103 if (!have_balloon(errp)) {
Luiz Capitulino96637bc2011-10-21 11:41:37 -0200104 return NULL;
Paolo Bonzini28c28972010-04-01 19:57:12 +0200105 }
106
Markus Armbruster6502a142015-01-13 17:43:25 +0100107 info = g_malloc0(sizeof(*info));
108 balloon_stat_fn(balloon_opaque, info);
Luiz Capitulino96637bc2011-10-21 11:41:37 -0200109 return info;
Paolo Bonzini28c28972010-04-01 19:57:12 +0200110}
111
Markus Armbruster6502a142015-01-13 17:43:25 +0100112void qmp_balloon(int64_t target, Error **errp)
Paolo Bonzini28c28972010-04-01 19:57:12 +0200113{
Eric Blake438e8282015-02-10 15:40:30 -0700114 if (!have_balloon(errp)) {
Luiz Capitulinod72f3262011-11-25 14:38:09 -0200115 return;
Paolo Bonzini28c28972010-04-01 19:57:12 +0200116 }
117
Markus Armbruster6502a142015-01-13 17:43:25 +0100118 if (target <= 0) {
Markus Armbrusterc6bd8c72015-03-17 11:54:50 +0100119 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "target", "a size");
Luiz Capitulinod72f3262011-11-25 14:38:09 -0200120 return;
Amit Shah514e73e2011-07-27 16:50:54 +0530121 }
Markus Armbruster6502a142015-01-13 17:43:25 +0100122
123 trace_balloon_event(balloon_opaque, target);
124 balloon_event_fn(balloon_opaque, target);
Paolo Bonzini28c28972010-04-01 19:57:12 +0200125}