xref: /illumos-kvm-cmd/balloon.c (revision 68396ea9)
1 /*
2  * QEMU System Emulator
3  *
4  * Copyright (c) 2003-2008 Fabrice Bellard
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to deal
8  * in the Software without restriction, including without limitation the rights
9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10  * copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22  * THE SOFTWARE.
23  */
24 
25 #include "sysemu.h"
26 #include "monitor.h"
27 #include "qjson.h"
28 #include "qint.h"
29 #include "cpu-common.h"
30 #include "kvm.h"
31 #include "balloon.h"
32 #include "trace.h"
33 
34 
35 static QEMUBalloonEvent *qemu_balloon_event;
36 void *qemu_balloon_event_opaque;
37 
qemu_add_balloon_handler(QEMUBalloonEvent * func,void * opaque)38 void qemu_add_balloon_handler(QEMUBalloonEvent *func, void *opaque)
39 {
40     qemu_balloon_event = func;
41     qemu_balloon_event_opaque = opaque;
42 }
43 
qemu_balloon(ram_addr_t target,MonitorCompletion cb,void * opaque)44 int qemu_balloon(ram_addr_t target, MonitorCompletion cb, void *opaque)
45 {
46     if (qemu_balloon_event) {
47         trace_balloon_event(qemu_balloon_event_opaque, target);
48         qemu_balloon_event(qemu_balloon_event_opaque, target, cb, opaque);
49         return 1;
50     } else {
51         return 0;
52     }
53 }
54 
qemu_balloon_status(MonitorCompletion cb,void * opaque)55 int qemu_balloon_status(MonitorCompletion cb, void *opaque)
56 {
57     if (qemu_balloon_event) {
58         qemu_balloon_event(qemu_balloon_event_opaque, 0, cb, opaque);
59         return 1;
60     } else {
61         return 0;
62     }
63 }
64 
print_balloon_stat(const char * key,QObject * obj,void * opaque)65 static void print_balloon_stat(const char *key, QObject *obj, void *opaque)
66 {
67     Monitor *mon = opaque;
68 
69     if (strcmp(key, "actual"))
70         monitor_printf(mon, ",%s=%" PRId64, key,
71                        qint_get_int(qobject_to_qint(obj)));
72 }
73 
monitor_print_balloon(Monitor * mon,const QObject * data)74 void monitor_print_balloon(Monitor *mon, const QObject *data)
75 {
76     QDict *qdict;
77 
78     qdict = qobject_to_qdict(data);
79     if (!qdict_haskey(qdict, "actual"))
80         return;
81 
82     monitor_printf(mon, "balloon: actual=%" PRId64,
83                    qdict_get_int(qdict, "actual") >> 20);
84     qdict_iter(qdict, print_balloon_stat, mon);
85     monitor_printf(mon, "\n");
86 }
87 
88 /**
89  * do_info_balloon(): Balloon information
90  *
91  * Make an asynchronous request for balloon info.  When the request completes
92  * a QDict will be returned according to the following specification:
93  *
94  * - "actual": current balloon value in bytes
95  * The following fields may or may not be present:
96  * - "mem_swapped_in": Amount of memory swapped in (bytes)
97  * - "mem_swapped_out": Amount of memory swapped out (bytes)
98  * - "major_page_faults": Number of major faults
99  * - "minor_page_faults": Number of minor faults
100  * - "free_mem": Total amount of free and unused memory (bytes)
101  * - "total_mem": Total amount of available memory (bytes)
102  *
103  * Example:
104  *
105  * { "actual": 1073741824, "mem_swapped_in": 0, "mem_swapped_out": 0,
106  *   "major_page_faults": 142, "minor_page_faults": 239245,
107  *   "free_mem": 1014185984, "total_mem": 1044668416 }
108  */
do_info_balloon(Monitor * mon,MonitorCompletion cb,void * opaque)109 int do_info_balloon(Monitor *mon, MonitorCompletion cb, void *opaque)
110 {
111     int ret;
112 
113     if (kvm_enabled() && !kvm_has_sync_mmu()) {
114         qerror_report(QERR_KVM_MISSING_CAP, "synchronous MMU", "balloon");
115         return -1;
116     }
117 
118     ret = qemu_balloon_status(cb, opaque);
119     if (!ret) {
120         qerror_report(QERR_DEVICE_NOT_ACTIVE, "balloon");
121         return -1;
122     }
123 
124     return 0;
125 }
126 
127 /**
128  * do_balloon(): Request VM to change its memory allocation
129  */
do_balloon(Monitor * mon,const QDict * params,MonitorCompletion cb,void * opaque)130 int do_balloon(Monitor *mon, const QDict *params,
131 	       MonitorCompletion cb, void *opaque)
132 {
133     int ret;
134 
135     if (kvm_enabled() && !kvm_has_sync_mmu()) {
136         qerror_report(QERR_KVM_MISSING_CAP, "synchronous MMU", "balloon");
137         return -1;
138     }
139 
140     ret = qemu_balloon(qdict_get_int(params, "value"), cb, opaque);
141     if (ret == 0) {
142         qerror_report(QERR_DEVICE_NOT_ACTIVE, "balloon");
143         return -1;
144     }
145 
146     cb(opaque, NULL);
147     return 0;
148 }
149