Provide the missing LIBUSB_LOG_LEVEL_* for older libusb or FreeBSD. Providing just...
[qemu.git] / balloon.c
1 /*
2 * Generic Balloon handlers and management
3 *
4 * Copyright (c) 2003-2008 Fabrice Bellard
5 * Copyright (C) 2011 Red Hat, Inc.
6 * Copyright (C) 2011 Amit Shah <amit.shah@redhat.com>
7 *
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
27 #include "monitor/monitor.h"
28 #include "exec/cpu-common.h"
29 #include "sysemu/kvm.h"
30 #include "sysemu/balloon.h"
31 #include "trace.h"
32 #include "qmp-commands.h"
33 #include "qapi/qmp/qjson.h"
34
35 static QEMUBalloonEvent *balloon_event_fn;
36 static QEMUBalloonStatus *balloon_stat_fn;
37 static void *balloon_opaque;
38
39 int qemu_add_balloon_handler(QEMUBalloonEvent *event_func,
40 QEMUBalloonStatus *stat_func, void *opaque)
41 {
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?
45 */
46 error_report("Another balloon device already registered");
47 return -1;
48 }
49 balloon_event_fn = event_func;
50 balloon_stat_fn = stat_func;
51 balloon_opaque = opaque;
52 return 0;
53 }
54
55 void qemu_remove_balloon_handler(void *opaque)
56 {
57 if (balloon_opaque != opaque) {
58 return;
59 }
60 balloon_event_fn = NULL;
61 balloon_stat_fn = NULL;
62 balloon_opaque = NULL;
63 }
64
65 static int qemu_balloon(ram_addr_t target)
66 {
67 if (!balloon_event_fn) {
68 return 0;
69 }
70 trace_balloon_event(balloon_opaque, target);
71 balloon_event_fn(balloon_opaque, target);
72 return 1;
73 }
74
75 static int qemu_balloon_status(BalloonInfo *info)
76 {
77 if (!balloon_stat_fn) {
78 return 0;
79 }
80 balloon_stat_fn(balloon_opaque, info);
81 return 1;
82 }
83
84 BalloonInfo *qmp_query_balloon(Error **errp)
85 {
86 BalloonInfo *info;
87
88 if (kvm_enabled() && !kvm_has_sync_mmu()) {
89 error_set(errp, QERR_KVM_MISSING_CAP, "synchronous MMU", "balloon");
90 return NULL;
91 }
92
93 info = g_malloc0(sizeof(*info));
94
95 if (qemu_balloon_status(info) == 0) {
96 error_set(errp, QERR_DEVICE_NOT_ACTIVE, "balloon");
97 qapi_free_BalloonInfo(info);
98 return NULL;
99 }
100
101 return info;
102 }
103
104 void qmp_balloon(int64_t value, Error **errp)
105 {
106 if (kvm_enabled() && !kvm_has_sync_mmu()) {
107 error_set(errp, QERR_KVM_MISSING_CAP, "synchronous MMU", "balloon");
108 return;
109 }
110
111 if (value <= 0) {
112 error_set(errp, QERR_INVALID_PARAMETER_VALUE, "target", "a size");
113 return;
114 }
115
116 if (qemu_balloon(value) == 0) {
117 error_set(errp, QERR_DEVICE_NOT_ACTIVE, "balloon");
118 }
119 }