qapi event: convert BALLOON_CHANGE
[qemu.git] / hw / virtio / virtio-balloon.c
1 /*
2 * Virtio Balloon Device
3 *
4 * Copyright IBM, Corp. 2008
5 * Copyright (C) 2011 Red Hat, Inc.
6 * Copyright (C) 2011 Amit Shah <amit.shah@redhat.com>
7 *
8 * Authors:
9 * Anthony Liguori <aliguori@us.ibm.com>
10 *
11 * This work is licensed under the terms of the GNU GPL, version 2. See
12 * the COPYING file in the top-level directory.
13 *
14 */
15
16 #include "qemu/iov.h"
17 #include "qemu/timer.h"
18 #include "qemu-common.h"
19 #include "hw/virtio/virtio.h"
20 #include "hw/i386/pc.h"
21 #include "cpu.h"
22 #include "sysemu/balloon.h"
23 #include "hw/virtio/virtio-balloon.h"
24 #include "sysemu/kvm.h"
25 #include "exec/address-spaces.h"
26 #include "qapi/visitor.h"
27 #include "qapi-event.h"
28
29 #if defined(__linux__)
30 #include <sys/mman.h>
31 #endif
32
33 #include "hw/virtio/virtio-bus.h"
34
35 static void balloon_page(void *addr, int deflate)
36 {
37 #if defined(__linux__)
38 if (!kvm_enabled() || kvm_has_sync_mmu())
39 qemu_madvise(addr, TARGET_PAGE_SIZE,
40 deflate ? QEMU_MADV_WILLNEED : QEMU_MADV_DONTNEED);
41 #endif
42 }
43
44 static const char *balloon_stat_names[] = {
45 [VIRTIO_BALLOON_S_SWAP_IN] = "stat-swap-in",
46 [VIRTIO_BALLOON_S_SWAP_OUT] = "stat-swap-out",
47 [VIRTIO_BALLOON_S_MAJFLT] = "stat-major-faults",
48 [VIRTIO_BALLOON_S_MINFLT] = "stat-minor-faults",
49 [VIRTIO_BALLOON_S_MEMFREE] = "stat-free-memory",
50 [VIRTIO_BALLOON_S_MEMTOT] = "stat-total-memory",
51 [VIRTIO_BALLOON_S_NR] = NULL
52 };
53
54 /*
55 * reset_stats - Mark all items in the stats array as unset
56 *
57 * This function needs to be called at device initialization and before
58 * updating to a set of newly-generated stats. This will ensure that no
59 * stale values stick around in case the guest reports a subset of the supported
60 * statistics.
61 */
62 static inline void reset_stats(VirtIOBalloon *dev)
63 {
64 int i;
65 for (i = 0; i < VIRTIO_BALLOON_S_NR; dev->stats[i++] = -1);
66 }
67
68 static bool balloon_stats_supported(const VirtIOBalloon *s)
69 {
70 VirtIODevice *vdev = VIRTIO_DEVICE(s);
71 return vdev->guest_features & (1 << VIRTIO_BALLOON_F_STATS_VQ);
72 }
73
74 static bool balloon_stats_enabled(const VirtIOBalloon *s)
75 {
76 return s->stats_poll_interval > 0;
77 }
78
79 static void balloon_stats_destroy_timer(VirtIOBalloon *s)
80 {
81 if (balloon_stats_enabled(s)) {
82 timer_del(s->stats_timer);
83 timer_free(s->stats_timer);
84 s->stats_timer = NULL;
85 s->stats_poll_interval = 0;
86 }
87 }
88
89 static void balloon_stats_change_timer(VirtIOBalloon *s, int secs)
90 {
91 timer_mod(s->stats_timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + secs * 1000);
92 }
93
94 static void balloon_stats_poll_cb(void *opaque)
95 {
96 VirtIOBalloon *s = opaque;
97 VirtIODevice *vdev = VIRTIO_DEVICE(s);
98
99 if (!balloon_stats_supported(s)) {
100 /* re-schedule */
101 balloon_stats_change_timer(s, s->stats_poll_interval);
102 return;
103 }
104
105 virtqueue_push(s->svq, &s->stats_vq_elem, s->stats_vq_offset);
106 virtio_notify(vdev, s->svq);
107 }
108
109 static void balloon_stats_get_all(Object *obj, struct Visitor *v,
110 void *opaque, const char *name, Error **errp)
111 {
112 Error *err = NULL;
113 VirtIOBalloon *s = opaque;
114 int i;
115
116 visit_start_struct(v, NULL, "guest-stats", name, 0, &err);
117 if (err) {
118 goto out;
119 }
120 visit_type_int(v, &s->stats_last_update, "last-update", &err);
121 if (err) {
122 goto out_end;
123 }
124
125 visit_start_struct(v, NULL, NULL, "stats", 0, &err);
126 if (err) {
127 goto out_end;
128 }
129 for (i = 0; !err && i < VIRTIO_BALLOON_S_NR; i++) {
130 visit_type_int64(v, (int64_t *) &s->stats[i], balloon_stat_names[i],
131 &err);
132 }
133 error_propagate(errp, err);
134 err = NULL;
135 visit_end_struct(v, &err);
136
137 out_end:
138 error_propagate(errp, err);
139 err = NULL;
140 visit_end_struct(v, &err);
141 out:
142 error_propagate(errp, err);
143 }
144
145 static void balloon_stats_get_poll_interval(Object *obj, struct Visitor *v,
146 void *opaque, const char *name,
147 Error **errp)
148 {
149 VirtIOBalloon *s = opaque;
150 visit_type_int(v, &s->stats_poll_interval, name, errp);
151 }
152
153 static void balloon_stats_set_poll_interval(Object *obj, struct Visitor *v,
154 void *opaque, const char *name,
155 Error **errp)
156 {
157 VirtIOBalloon *s = opaque;
158 Error *local_err = NULL;
159 int64_t value;
160
161 visit_type_int(v, &value, name, &local_err);
162 if (local_err) {
163 error_propagate(errp, local_err);
164 return;
165 }
166
167 if (value < 0) {
168 error_setg(errp, "timer value must be greater than zero");
169 return;
170 }
171
172 if (value == s->stats_poll_interval) {
173 return;
174 }
175
176 if (value == 0) {
177 /* timer=0 disables the timer */
178 balloon_stats_destroy_timer(s);
179 return;
180 }
181
182 if (balloon_stats_enabled(s)) {
183 /* timer interval change */
184 s->stats_poll_interval = value;
185 balloon_stats_change_timer(s, value);
186 return;
187 }
188
189 /* create a new timer */
190 g_assert(s->stats_timer == NULL);
191 s->stats_timer = timer_new_ms(QEMU_CLOCK_VIRTUAL, balloon_stats_poll_cb, s);
192 s->stats_poll_interval = value;
193 balloon_stats_change_timer(s, 0);
194 }
195
196 static void virtio_balloon_handle_output(VirtIODevice *vdev, VirtQueue *vq)
197 {
198 VirtIOBalloon *s = VIRTIO_BALLOON(vdev);
199 VirtQueueElement elem;
200 MemoryRegionSection section;
201
202 while (virtqueue_pop(vq, &elem)) {
203 size_t offset = 0;
204 uint32_t pfn;
205
206 while (iov_to_buf(elem.out_sg, elem.out_num, offset, &pfn, 4) == 4) {
207 ram_addr_t pa;
208 ram_addr_t addr;
209
210 pa = (ram_addr_t)ldl_p(&pfn) << VIRTIO_BALLOON_PFN_SHIFT;
211 offset += 4;
212
213 /* FIXME: remove get_system_memory(), but how? */
214 section = memory_region_find(get_system_memory(), pa, 1);
215 if (!int128_nz(section.size) || !memory_region_is_ram(section.mr))
216 continue;
217
218 /* Using memory_region_get_ram_ptr is bending the rules a bit, but
219 should be OK because we only want a single page. */
220 addr = section.offset_within_region;
221 balloon_page(memory_region_get_ram_ptr(section.mr) + addr,
222 !!(vq == s->dvq));
223 memory_region_unref(section.mr);
224 }
225
226 virtqueue_push(vq, &elem, offset);
227 virtio_notify(vdev, vq);
228 }
229 }
230
231 static void virtio_balloon_receive_stats(VirtIODevice *vdev, VirtQueue *vq)
232 {
233 VirtIOBalloon *s = VIRTIO_BALLOON(vdev);
234 VirtQueueElement *elem = &s->stats_vq_elem;
235 VirtIOBalloonStat stat;
236 size_t offset = 0;
237 qemu_timeval tv;
238
239 if (!virtqueue_pop(vq, elem)) {
240 goto out;
241 }
242
243 /* Initialize the stats to get rid of any stale values. This is only
244 * needed to handle the case where a guest supports fewer stats than it
245 * used to (ie. it has booted into an old kernel).
246 */
247 reset_stats(s);
248
249 while (iov_to_buf(elem->out_sg, elem->out_num, offset, &stat, sizeof(stat))
250 == sizeof(stat)) {
251 uint16_t tag = tswap16(stat.tag);
252 uint64_t val = tswap64(stat.val);
253
254 offset += sizeof(stat);
255 if (tag < VIRTIO_BALLOON_S_NR)
256 s->stats[tag] = val;
257 }
258 s->stats_vq_offset = offset;
259
260 if (qemu_gettimeofday(&tv) < 0) {
261 fprintf(stderr, "warning: %s: failed to get time of day\n", __func__);
262 goto out;
263 }
264
265 s->stats_last_update = tv.tv_sec;
266
267 out:
268 if (balloon_stats_enabled(s)) {
269 balloon_stats_change_timer(s, s->stats_poll_interval);
270 }
271 }
272
273 static void virtio_balloon_get_config(VirtIODevice *vdev, uint8_t *config_data)
274 {
275 VirtIOBalloon *dev = VIRTIO_BALLOON(vdev);
276 struct virtio_balloon_config config;
277
278 config.num_pages = cpu_to_le32(dev->num_pages);
279 config.actual = cpu_to_le32(dev->actual);
280
281 memcpy(config_data, &config, sizeof(struct virtio_balloon_config));
282 }
283
284 static void virtio_balloon_set_config(VirtIODevice *vdev,
285 const uint8_t *config_data)
286 {
287 VirtIOBalloon *dev = VIRTIO_BALLOON(vdev);
288 struct virtio_balloon_config config;
289 uint32_t oldactual = dev->actual;
290 memcpy(&config, config_data, sizeof(struct virtio_balloon_config));
291 dev->actual = le32_to_cpu(config.actual);
292 if (dev->actual != oldactual) {
293 qapi_event_send_balloon_change(ram_size -
294 ((ram_addr_t) dev->actual << VIRTIO_BALLOON_PFN_SHIFT),
295 &error_abort);
296 }
297 }
298
299 static uint32_t virtio_balloon_get_features(VirtIODevice *vdev, uint32_t f)
300 {
301 f |= (1 << VIRTIO_BALLOON_F_STATS_VQ);
302 return f;
303 }
304
305 static void virtio_balloon_stat(void *opaque, BalloonInfo *info)
306 {
307 VirtIOBalloon *dev = opaque;
308 info->actual = ram_size - ((uint64_t) dev->actual <<
309 VIRTIO_BALLOON_PFN_SHIFT);
310 }
311
312 static void virtio_balloon_to_target(void *opaque, ram_addr_t target)
313 {
314 VirtIOBalloon *dev = VIRTIO_BALLOON(opaque);
315 VirtIODevice *vdev = VIRTIO_DEVICE(dev);
316
317 if (target > ram_size) {
318 target = ram_size;
319 }
320 if (target) {
321 dev->num_pages = (ram_size - target) >> VIRTIO_BALLOON_PFN_SHIFT;
322 virtio_notify_config(vdev);
323 }
324 }
325
326 static void virtio_balloon_save(QEMUFile *f, void *opaque)
327 {
328 VirtIOBalloon *s = VIRTIO_BALLOON(opaque);
329 VirtIODevice *vdev = VIRTIO_DEVICE(s);
330
331 virtio_save(vdev, f);
332
333 qemu_put_be32(f, s->num_pages);
334 qemu_put_be32(f, s->actual);
335 }
336
337 static int virtio_balloon_load(QEMUFile *f, void *opaque, int version_id)
338 {
339 VirtIOBalloon *s = VIRTIO_BALLOON(opaque);
340 VirtIODevice *vdev = VIRTIO_DEVICE(s);
341 int ret;
342
343 if (version_id != 1)
344 return -EINVAL;
345
346 ret = virtio_load(vdev, f);
347 if (ret) {
348 return ret;
349 }
350
351 s->num_pages = qemu_get_be32(f);
352 s->actual = qemu_get_be32(f);
353 return 0;
354 }
355
356 static void virtio_balloon_device_realize(DeviceState *dev, Error **errp)
357 {
358 VirtIODevice *vdev = VIRTIO_DEVICE(dev);
359 VirtIOBalloon *s = VIRTIO_BALLOON(dev);
360 int ret;
361
362 virtio_init(vdev, "virtio-balloon", VIRTIO_ID_BALLOON,
363 sizeof(struct virtio_balloon_config));
364
365 ret = qemu_add_balloon_handler(virtio_balloon_to_target,
366 virtio_balloon_stat, s);
367
368 if (ret < 0) {
369 error_setg(errp, "Adding balloon handler failed");
370 virtio_cleanup(vdev);
371 return;
372 }
373
374 s->ivq = virtio_add_queue(vdev, 128, virtio_balloon_handle_output);
375 s->dvq = virtio_add_queue(vdev, 128, virtio_balloon_handle_output);
376 s->svq = virtio_add_queue(vdev, 128, virtio_balloon_receive_stats);
377
378 reset_stats(s);
379
380 register_savevm(dev, "virtio-balloon", -1, 1,
381 virtio_balloon_save, virtio_balloon_load, s);
382
383 object_property_add(OBJECT(dev), "guest-stats", "guest statistics",
384 balloon_stats_get_all, NULL, NULL, s, NULL);
385
386 object_property_add(OBJECT(dev), "guest-stats-polling-interval", "int",
387 balloon_stats_get_poll_interval,
388 balloon_stats_set_poll_interval,
389 NULL, s, NULL);
390 }
391
392 static void virtio_balloon_device_unrealize(DeviceState *dev, Error **errp)
393 {
394 VirtIODevice *vdev = VIRTIO_DEVICE(dev);
395 VirtIOBalloon *s = VIRTIO_BALLOON(dev);
396
397 balloon_stats_destroy_timer(s);
398 qemu_remove_balloon_handler(s);
399 unregister_savevm(dev, "virtio-balloon", s);
400 virtio_cleanup(vdev);
401 }
402
403 static Property virtio_balloon_properties[] = {
404 DEFINE_PROP_END_OF_LIST(),
405 };
406
407 static void virtio_balloon_class_init(ObjectClass *klass, void *data)
408 {
409 DeviceClass *dc = DEVICE_CLASS(klass);
410 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
411
412 dc->props = virtio_balloon_properties;
413 set_bit(DEVICE_CATEGORY_MISC, dc->categories);
414 vdc->realize = virtio_balloon_device_realize;
415 vdc->unrealize = virtio_balloon_device_unrealize;
416 vdc->get_config = virtio_balloon_get_config;
417 vdc->set_config = virtio_balloon_set_config;
418 vdc->get_features = virtio_balloon_get_features;
419 }
420
421 static const TypeInfo virtio_balloon_info = {
422 .name = TYPE_VIRTIO_BALLOON,
423 .parent = TYPE_VIRTIO_DEVICE,
424 .instance_size = sizeof(VirtIOBalloon),
425 .class_init = virtio_balloon_class_init,
426 };
427
428 static void virtio_register_types(void)
429 {
430 type_register_static(&virtio_balloon_info);
431 }
432
433 type_init(virtio_register_types)