1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16#include "qemu/osdep.h"
17#include "qemu/iov.h"
18#include "qemu/timer.h"
19#include "qemu-common.h"
20#include "hw/virtio/virtio.h"
21#include "hw/i386/pc.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#include "trace.h"
29#include "qemu/error-report.h"
30
31#include "hw/virtio/virtio-bus.h"
32#include "hw/virtio/virtio-access.h"
33
34#define BALLOON_PAGE_SIZE (1 << VIRTIO_BALLOON_PFN_SHIFT)
35
36static void balloon_page(void *addr, int deflate)
37{
38 if (!qemu_balloon_is_inhibited() && (!kvm_enabled() ||
39 kvm_has_sync_mmu())) {
40 qemu_madvise(addr, BALLOON_PAGE_SIZE,
41 deflate ? QEMU_MADV_WILLNEED : QEMU_MADV_DONTNEED);
42 }
43}
44
45static const char *balloon_stat_names[] = {
46 [VIRTIO_BALLOON_S_SWAP_IN] = "stat-swap-in",
47 [VIRTIO_BALLOON_S_SWAP_OUT] = "stat-swap-out",
48 [VIRTIO_BALLOON_S_MAJFLT] = "stat-major-faults",
49 [VIRTIO_BALLOON_S_MINFLT] = "stat-minor-faults",
50 [VIRTIO_BALLOON_S_MEMFREE] = "stat-free-memory",
51 [VIRTIO_BALLOON_S_MEMTOT] = "stat-total-memory",
52 [VIRTIO_BALLOON_S_AVAIL] = "stat-available-memory",
53 [VIRTIO_BALLOON_S_NR] = NULL
54};
55
56
57
58
59
60
61
62
63
64static inline void reset_stats(VirtIOBalloon *dev)
65{
66 int i;
67 for (i = 0; i < VIRTIO_BALLOON_S_NR; dev->stats[i++] = -1);
68}
69
70static bool balloon_stats_supported(const VirtIOBalloon *s)
71{
72 VirtIODevice *vdev = VIRTIO_DEVICE(s);
73 return virtio_vdev_has_feature(vdev, VIRTIO_BALLOON_F_STATS_VQ);
74}
75
76static bool balloon_stats_enabled(const VirtIOBalloon *s)
77{
78 return s->stats_poll_interval > 0;
79}
80
81static void balloon_stats_destroy_timer(VirtIOBalloon *s)
82{
83 if (balloon_stats_enabled(s)) {
84 timer_del(s->stats_timer);
85 timer_free(s->stats_timer);
86 s->stats_timer = NULL;
87 s->stats_poll_interval = 0;
88 }
89}
90
91static void balloon_stats_change_timer(VirtIOBalloon *s, int64_t secs)
92{
93 timer_mod(s->stats_timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + secs * 1000);
94}
95
96static void balloon_stats_poll_cb(void *opaque)
97{
98 VirtIOBalloon *s = opaque;
99 VirtIODevice *vdev = VIRTIO_DEVICE(s);
100
101 if (s->stats_vq_elem == NULL || !balloon_stats_supported(s)) {
102
103 balloon_stats_change_timer(s, s->stats_poll_interval);
104 return;
105 }
106
107 virtqueue_push(s->svq, s->stats_vq_elem, s->stats_vq_offset);
108 virtio_notify(vdev, s->svq);
109 g_free(s->stats_vq_elem);
110 s->stats_vq_elem = NULL;
111}
112
113static void balloon_stats_get_all(Object *obj, Visitor *v, const char *name,
114 void *opaque, Error **errp)
115{
116 Error *err = NULL;
117 VirtIOBalloon *s = opaque;
118 int i;
119
120 visit_start_struct(v, name, NULL, 0, &err);
121 if (err) {
122 goto out;
123 }
124 visit_type_int(v, "last-update", &s->stats_last_update, &err);
125 if (err) {
126 goto out_end;
127 }
128
129 visit_start_struct(v, "stats", NULL, 0, &err);
130 if (err) {
131 goto out_end;
132 }
133 for (i = 0; i < VIRTIO_BALLOON_S_NR; i++) {
134 visit_type_uint64(v, balloon_stat_names[i], &s->stats[i], &err);
135 if (err) {
136 goto out_nested;
137 }
138 }
139 visit_check_struct(v, &err);
140out_nested:
141 visit_end_struct(v, NULL);
142
143 if (!err) {
144 visit_check_struct(v, &err);
145 }
146out_end:
147 visit_end_struct(v, NULL);
148out:
149 error_propagate(errp, err);
150}
151
152static void balloon_stats_get_poll_interval(Object *obj, Visitor *v,
153 const char *name, void *opaque,
154 Error **errp)
155{
156 VirtIOBalloon *s = opaque;
157 visit_type_int(v, name, &s->stats_poll_interval, errp);
158}
159
160static void balloon_stats_set_poll_interval(Object *obj, Visitor *v,
161 const char *name, void *opaque,
162 Error **errp)
163{
164 VirtIOBalloon *s = opaque;
165 Error *local_err = NULL;
166 int64_t value;
167
168 visit_type_int(v, name, &value, &local_err);
169 if (local_err) {
170 error_propagate(errp, local_err);
171 return;
172 }
173
174 if (value < 0) {
175 error_setg(errp, "timer value must be greater than zero");
176 return;
177 }
178
179 if (value > UINT32_MAX) {
180 error_setg(errp, "timer value is too big");
181 return;
182 }
183
184 if (value == s->stats_poll_interval) {
185 return;
186 }
187
188 if (value == 0) {
189
190 balloon_stats_destroy_timer(s);
191 return;
192 }
193
194 if (balloon_stats_enabled(s)) {
195
196 s->stats_poll_interval = value;
197 balloon_stats_change_timer(s, value);
198 return;
199 }
200
201
202 g_assert(s->stats_timer == NULL);
203 s->stats_timer = timer_new_ms(QEMU_CLOCK_VIRTUAL, balloon_stats_poll_cb, s);
204 s->stats_poll_interval = value;
205 balloon_stats_change_timer(s, 0);
206}
207
208static void virtio_balloon_handle_output(VirtIODevice *vdev, VirtQueue *vq)
209{
210 VirtIOBalloon *s = VIRTIO_BALLOON(vdev);
211 VirtQueueElement *elem;
212 MemoryRegionSection section;
213
214 for (;;) {
215 size_t offset = 0;
216 uint32_t pfn;
217 elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
218 if (!elem) {
219 return;
220 }
221
222 while (iov_to_buf(elem->out_sg, elem->out_num, offset, &pfn, 4) == 4) {
223 ram_addr_t pa;
224 ram_addr_t addr;
225 int p = virtio_ldl_p(vdev, &pfn);
226
227 pa = (ram_addr_t) p << VIRTIO_BALLOON_PFN_SHIFT;
228 offset += 4;
229
230
231 section = memory_region_find(get_system_memory(), pa, 1);
232 if (!int128_nz(section.size) ||
233 !memory_region_is_ram(section.mr) ||
234 memory_region_is_rom(section.mr) ||
235 memory_region_is_romd(section.mr)) {
236 trace_virtio_balloon_bad_addr(pa);
237 memory_region_unref(section.mr);
238 continue;
239 }
240
241 trace_virtio_balloon_handle_output(memory_region_name(section.mr),
242 pa);
243
244
245 addr = section.offset_within_region;
246 balloon_page(memory_region_get_ram_ptr(section.mr) + addr,
247 !!(vq == s->dvq));
248 memory_region_unref(section.mr);
249 }
250
251 virtqueue_push(vq, elem, offset);
252 virtio_notify(vdev, vq);
253 g_free(elem);
254 }
255}
256
257static void virtio_balloon_receive_stats(VirtIODevice *vdev, VirtQueue *vq)
258{
259 VirtIOBalloon *s = VIRTIO_BALLOON(vdev);
260 VirtQueueElement *elem;
261 VirtIOBalloonStat stat;
262 size_t offset = 0;
263 qemu_timeval tv;
264
265 elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
266 if (!elem) {
267 goto out;
268 }
269
270 if (s->stats_vq_elem != NULL) {
271
272 virtqueue_push(vq, s->stats_vq_elem, 0);
273 virtio_notify(vdev, vq);
274 g_free(s->stats_vq_elem);
275 }
276
277 s->stats_vq_elem = elem;
278
279
280
281
282
283 reset_stats(s);
284
285 while (iov_to_buf(elem->out_sg, elem->out_num, offset, &stat, sizeof(stat))
286 == sizeof(stat)) {
287 uint16_t tag = virtio_tswap16(vdev, stat.tag);
288 uint64_t val = virtio_tswap64(vdev, stat.val);
289
290 offset += sizeof(stat);
291 if (tag < VIRTIO_BALLOON_S_NR)
292 s->stats[tag] = val;
293 }
294 s->stats_vq_offset = offset;
295
296 if (qemu_gettimeofday(&tv) < 0) {
297 warn_report("%s: failed to get time of day", __func__);
298 goto out;
299 }
300
301 s->stats_last_update = tv.tv_sec;
302
303out:
304 if (balloon_stats_enabled(s)) {
305 balloon_stats_change_timer(s, s->stats_poll_interval);
306 }
307}
308
309static void virtio_balloon_get_config(VirtIODevice *vdev, uint8_t *config_data)
310{
311 VirtIOBalloon *dev = VIRTIO_BALLOON(vdev);
312 struct virtio_balloon_config config;
313
314 config.num_pages = cpu_to_le32(dev->num_pages);
315 config.actual = cpu_to_le32(dev->actual);
316
317 trace_virtio_balloon_get_config(config.num_pages, config.actual);
318 memcpy(config_data, &config, sizeof(struct virtio_balloon_config));
319}
320
321static int build_dimm_list(Object *obj, void *opaque)
322{
323 GSList **list = opaque;
324
325 if (object_dynamic_cast(obj, TYPE_PC_DIMM)) {
326 DeviceState *dev = DEVICE(obj);
327 if (dev->realized) {
328 *list = g_slist_prepend(*list, dev);
329 }
330 }
331
332 object_child_foreach(obj, build_dimm_list, opaque);
333 return 0;
334}
335
336static ram_addr_t get_current_ram_size(void)
337{
338 GSList *list = NULL, *item;
339 ram_addr_t size = ram_size;
340
341 build_dimm_list(qdev_get_machine(), &list);
342 for (item = list; item; item = g_slist_next(item)) {
343 Object *obj = OBJECT(item->data);
344 if (!strcmp(object_get_typename(obj), TYPE_PC_DIMM)) {
345 size += object_property_get_int(obj, PC_DIMM_SIZE_PROP,
346 &error_abort);
347 }
348 }
349 g_slist_free(list);
350
351 return size;
352}
353
354static void virtio_balloon_set_config(VirtIODevice *vdev,
355 const uint8_t *config_data)
356{
357 VirtIOBalloon *dev = VIRTIO_BALLOON(vdev);
358 struct virtio_balloon_config config;
359 uint32_t oldactual = dev->actual;
360 ram_addr_t vm_ram_size = get_current_ram_size();
361
362 memcpy(&config, config_data, sizeof(struct virtio_balloon_config));
363 dev->actual = le32_to_cpu(config.actual);
364 if (dev->actual != oldactual) {
365 qapi_event_send_balloon_change(vm_ram_size -
366 ((ram_addr_t) dev->actual << VIRTIO_BALLOON_PFN_SHIFT),
367 &error_abort);
368 }
369 trace_virtio_balloon_set_config(dev->actual, oldactual);
370}
371
372static uint64_t virtio_balloon_get_features(VirtIODevice *vdev, uint64_t f,
373 Error **errp)
374{
375 VirtIOBalloon *dev = VIRTIO_BALLOON(vdev);
376 f |= dev->host_features;
377 virtio_add_feature(&f, VIRTIO_BALLOON_F_STATS_VQ);
378 return f;
379}
380
381static void virtio_balloon_stat(void *opaque, BalloonInfo *info)
382{
383 VirtIOBalloon *dev = opaque;
384 info->actual = get_current_ram_size() - ((uint64_t) dev->actual <<
385 VIRTIO_BALLOON_PFN_SHIFT);
386}
387
388static void virtio_balloon_to_target(void *opaque, ram_addr_t target)
389{
390 VirtIOBalloon *dev = VIRTIO_BALLOON(opaque);
391 VirtIODevice *vdev = VIRTIO_DEVICE(dev);
392 ram_addr_t vm_ram_size = get_current_ram_size();
393
394 if (target > vm_ram_size) {
395 target = vm_ram_size;
396 }
397 if (target) {
398 dev->num_pages = (vm_ram_size - target) >> VIRTIO_BALLOON_PFN_SHIFT;
399 virtio_notify_config(vdev);
400 }
401 trace_virtio_balloon_to_target(target, dev->num_pages);
402}
403
404static int virtio_balloon_post_load_device(void *opaque, int version_id)
405{
406 VirtIOBalloon *s = VIRTIO_BALLOON(opaque);
407
408 if (balloon_stats_enabled(s)) {
409 balloon_stats_change_timer(s, s->stats_poll_interval);
410 }
411 return 0;
412}
413
414static const VMStateDescription vmstate_virtio_balloon_device = {
415 .name = "virtio-balloon-device",
416 .version_id = 1,
417 .minimum_version_id = 1,
418 .post_load = virtio_balloon_post_load_device,
419 .fields = (VMStateField[]) {
420 VMSTATE_UINT32(num_pages, VirtIOBalloon),
421 VMSTATE_UINT32(actual, VirtIOBalloon),
422 VMSTATE_END_OF_LIST()
423 },
424};
425
426static void virtio_balloon_device_realize(DeviceState *dev, Error **errp)
427{
428 VirtIODevice *vdev = VIRTIO_DEVICE(dev);
429 VirtIOBalloon *s = VIRTIO_BALLOON(dev);
430 int ret;
431
432 virtio_init(vdev, "virtio-balloon", VIRTIO_ID_BALLOON,
433 sizeof(struct virtio_balloon_config));
434
435 ret = qemu_add_balloon_handler(virtio_balloon_to_target,
436 virtio_balloon_stat, s);
437
438 if (ret < 0) {
439 error_setg(errp, "Only one balloon device is supported");
440 virtio_cleanup(vdev);
441 return;
442 }
443
444 s->ivq = virtio_add_queue(vdev, 128, virtio_balloon_handle_output);
445 s->dvq = virtio_add_queue(vdev, 128, virtio_balloon_handle_output);
446 s->svq = virtio_add_queue(vdev, 128, virtio_balloon_receive_stats);
447
448 reset_stats(s);
449}
450
451static void virtio_balloon_device_unrealize(DeviceState *dev, Error **errp)
452{
453 VirtIODevice *vdev = VIRTIO_DEVICE(dev);
454 VirtIOBalloon *s = VIRTIO_BALLOON(dev);
455
456 balloon_stats_destroy_timer(s);
457 qemu_remove_balloon_handler(s);
458 virtio_cleanup(vdev);
459}
460
461static void virtio_balloon_device_reset(VirtIODevice *vdev)
462{
463 VirtIOBalloon *s = VIRTIO_BALLOON(vdev);
464
465 if (s->stats_vq_elem != NULL) {
466 virtqueue_unpop(s->svq, s->stats_vq_elem, 0);
467 g_free(s->stats_vq_elem);
468 s->stats_vq_elem = NULL;
469 }
470}
471
472static void virtio_balloon_set_status(VirtIODevice *vdev, uint8_t status)
473{
474 VirtIOBalloon *s = VIRTIO_BALLOON(vdev);
475
476 if (!s->stats_vq_elem && vdev->vm_running &&
477 (status & VIRTIO_CONFIG_S_DRIVER_OK) && virtqueue_rewind(s->svq, 1)) {
478
479
480 virtio_balloon_receive_stats(vdev, s->svq);
481 }
482}
483
484static void virtio_balloon_instance_init(Object *obj)
485{
486 VirtIOBalloon *s = VIRTIO_BALLOON(obj);
487
488 object_property_add(obj, "guest-stats", "guest statistics",
489 balloon_stats_get_all, NULL, NULL, s, NULL);
490
491 object_property_add(obj, "guest-stats-polling-interval", "int",
492 balloon_stats_get_poll_interval,
493 balloon_stats_set_poll_interval,
494 NULL, s, NULL);
495}
496
497static const VMStateDescription vmstate_virtio_balloon = {
498 .name = "virtio-balloon",
499 .minimum_version_id = 1,
500 .version_id = 1,
501 .fields = (VMStateField[]) {
502 VMSTATE_VIRTIO_DEVICE,
503 VMSTATE_END_OF_LIST()
504 },
505};
506
507static Property virtio_balloon_properties[] = {
508 DEFINE_PROP_BIT("deflate-on-oom", VirtIOBalloon, host_features,
509 VIRTIO_BALLOON_F_DEFLATE_ON_OOM, false),
510 DEFINE_PROP_END_OF_LIST(),
511};
512
513static void virtio_balloon_class_init(ObjectClass *klass, void *data)
514{
515 DeviceClass *dc = DEVICE_CLASS(klass);
516 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
517
518 dc->props = virtio_balloon_properties;
519 dc->vmsd = &vmstate_virtio_balloon;
520 set_bit(DEVICE_CATEGORY_MISC, dc->categories);
521 vdc->realize = virtio_balloon_device_realize;
522 vdc->unrealize = virtio_balloon_device_unrealize;
523 vdc->reset = virtio_balloon_device_reset;
524 vdc->get_config = virtio_balloon_get_config;
525 vdc->set_config = virtio_balloon_set_config;
526 vdc->get_features = virtio_balloon_get_features;
527 vdc->set_status = virtio_balloon_set_status;
528 vdc->vmsd = &vmstate_virtio_balloon_device;
529}
530
531static const TypeInfo virtio_balloon_info = {
532 .name = TYPE_VIRTIO_BALLOON,
533 .parent = TYPE_VIRTIO_DEVICE,
534 .instance_size = sizeof(VirtIOBalloon),
535 .instance_init = virtio_balloon_instance_init,
536 .class_init = virtio_balloon_class_init,
537};
538
539static void virtio_register_types(void)
540{
541 type_register_static(&virtio_balloon_info);
542}
543
544type_init(virtio_register_types)
545