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
27 #include "qemu/osdep.h"
28 #include "qemu-common.h"
29 #include "exec/cpu-common.h"
30 #include "sysemu/kvm.h"
31 #include "sysemu/balloon.h"
32 #include "trace-root.h"
33 #include "qmp-commands.h"
34 #include "qapi/error.h"
35 #include "qapi/qmp/qerror.h"
37 static QEMUBalloonEvent
*balloon_event_fn
;
38 static QEMUBalloonStatus
*balloon_stat_fn
;
39 static void *balloon_opaque
;
40 static bool balloon_inhibited
;
42 bool qemu_balloon_is_inhibited(void)
44 return balloon_inhibited
;
47 void qemu_balloon_inhibit(bool state
)
49 balloon_inhibited
= state
;
52 static bool have_balloon(Error
**errp
)
54 if (kvm_enabled() && !kvm_has_sync_mmu()) {
55 error_set(errp
, ERROR_CLASS_KVM_MISSING_CAP
,
56 "Using KVM without synchronous MMU, balloon unavailable");
59 if (!balloon_event_fn
) {
60 error_set(errp
, ERROR_CLASS_DEVICE_NOT_ACTIVE
,
61 "No balloon device has been activated");
67 int qemu_add_balloon_handler(QEMUBalloonEvent
*event_func
,
68 QEMUBalloonStatus
*stat_func
, void *opaque
)
70 if (balloon_event_fn
|| balloon_stat_fn
|| balloon_opaque
) {
71 /* We're already registered one balloon handler. How many can
72 * a guest really have?
76 balloon_event_fn
= event_func
;
77 balloon_stat_fn
= stat_func
;
78 balloon_opaque
= opaque
;
82 void qemu_remove_balloon_handler(void *opaque
)
84 if (balloon_opaque
!= opaque
) {
87 balloon_event_fn
= NULL
;
88 balloon_stat_fn
= NULL
;
89 balloon_opaque
= NULL
;
92 BalloonInfo
*qmp_query_balloon(Error
**errp
)
96 if (!have_balloon(errp
)) {
100 info
= g_malloc0(sizeof(*info
));
101 balloon_stat_fn(balloon_opaque
, info
);
105 void qmp_balloon(int64_t target
, Error
**errp
)
107 if (!have_balloon(errp
)) {
112 error_setg(errp
, QERR_INVALID_PARAMETER_VALUE
, "target", "a size");
116 trace_balloon_event(balloon_opaque
, target
);
117 balloon_event_fn(balloon_opaque
, target
);