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