pseries: Add spapr_rtc_read() helper function
[qemu/ar7.git] / balloon.c
blob70c00f5f840b8f3c3a7f99f8112a7d541d17f6f4
1 /*
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
24 * THE SOFTWARE.
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"
35 static QEMUBalloonEvent *balloon_event_fn;
36 static QEMUBalloonStatus *balloon_stat_fn;
37 static void *balloon_opaque;
39 static bool have_balloon(Error **errp)
41 if (kvm_enabled() && !kvm_has_sync_mmu()) {
42 error_set(errp, ERROR_CLASS_KVM_MISSING_CAP,
43 "Using KVM without synchronous MMU, balloon unavailable");
44 return false;
46 if (!balloon_event_fn) {
47 error_set(errp, ERROR_CLASS_DEVICE_NOT_ACTIVE,
48 "No balloon device has been activated");
49 return false;
51 return true;
54 int qemu_add_balloon_handler(QEMUBalloonEvent *event_func,
55 QEMUBalloonStatus *stat_func, void *opaque)
57 if (balloon_event_fn || balloon_stat_fn || balloon_opaque) {
58 /* We're already registered one balloon handler. How many can
59 * a guest really have?
61 error_report("Another balloon device already registered");
62 return -1;
64 balloon_event_fn = event_func;
65 balloon_stat_fn = stat_func;
66 balloon_opaque = opaque;
67 return 0;
70 void qemu_remove_balloon_handler(void *opaque)
72 if (balloon_opaque != opaque) {
73 return;
75 balloon_event_fn = NULL;
76 balloon_stat_fn = NULL;
77 balloon_opaque = NULL;
80 BalloonInfo *qmp_query_balloon(Error **errp)
82 BalloonInfo *info;
84 if (!have_balloon(errp)) {
85 return NULL;
88 info = g_malloc0(sizeof(*info));
89 balloon_stat_fn(balloon_opaque, info);
90 return info;
93 void qmp_balloon(int64_t target, Error **errp)
95 if (!have_balloon(errp)) {
96 return;
99 if (target <= 0) {
100 error_set(errp, QERR_INVALID_PARAMETER_VALUE, "target", "a size");
101 return;
104 trace_balloon_event(balloon_opaque, target);
105 balloon_event_fn(balloon_opaque, target);