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16#include "qemu/osdep.h"
17#include "qemu/iov.h"
18#include "qemu/module.h"
19#include "qemu/timer.h"
20#include "hw/virtio/virtio.h"
21#include "hw/mem/pc-dimm.h"
22#include "hw/qdev-properties.h"
23#include "hw/boards.h"
24#include "sysemu/balloon.h"
25#include "hw/virtio/virtio-balloon.h"
26#include "exec/address-spaces.h"
27#include "qapi/error.h"
28#include "qapi/qapi-events-machine.h"
29#include "qapi/visitor.h"
30#include "trace.h"
31#include "qemu/error-report.h"
32#include "migration/misc.h"
33#include "migration/migration.h"
34
35#include "hw/virtio/virtio-bus.h"
36#include "hw/virtio/virtio-access.h"
37
38#define BALLOON_PAGE_SIZE (1 << VIRTIO_BALLOON_PFN_SHIFT)
39
40typedef struct PartiallyBalloonedPage {
41 ram_addr_t base_gpa;
42 unsigned long *bitmap;
43} PartiallyBalloonedPage;
44
45static void virtio_balloon_pbp_free(PartiallyBalloonedPage *pbp)
46{
47 if (!pbp->bitmap) {
48 return;
49 }
50 g_free(pbp->bitmap);
51 pbp->bitmap = NULL;
52}
53
54static void virtio_balloon_pbp_alloc(PartiallyBalloonedPage *pbp,
55 ram_addr_t base_gpa,
56 long subpages)
57{
58 pbp->base_gpa = base_gpa;
59 pbp->bitmap = bitmap_new(subpages);
60}
61
62static bool virtio_balloon_pbp_matches(PartiallyBalloonedPage *pbp,
63 ram_addr_t base_gpa)
64{
65 return pbp->base_gpa == base_gpa;
66}
67
68static bool virtio_balloon_inhibited(void)
69{
70
71
72
73
74 return ram_block_discard_is_disabled() || migration_in_incoming_postcopy() ||
75 migration_in_bg_snapshot();
76}
77
78static void balloon_inflate_page(VirtIOBalloon *balloon,
79 MemoryRegion *mr, hwaddr mr_offset,
80 PartiallyBalloonedPage *pbp)
81{
82 void *addr = memory_region_get_ram_ptr(mr) + mr_offset;
83 ram_addr_t rb_offset, rb_aligned_offset, base_gpa;
84 RAMBlock *rb;
85 size_t rb_page_size;
86 int subpages;
87
88
89
90 rb = qemu_ram_block_from_host(addr, false, &rb_offset);
91 rb_page_size = qemu_ram_pagesize(rb);
92
93 if (rb_page_size == BALLOON_PAGE_SIZE) {
94
95
96 ram_block_discard_range(rb, rb_offset, rb_page_size);
97
98
99
100 return;
101 }
102
103
104
105
106
107
108
109 warn_report_once(
110"Balloon used with backing page size > 4kiB, this may not be reliable");
111
112 rb_aligned_offset = QEMU_ALIGN_DOWN(rb_offset, rb_page_size);
113 subpages = rb_page_size / BALLOON_PAGE_SIZE;
114 base_gpa = memory_region_get_ram_addr(mr) + mr_offset -
115 (rb_offset - rb_aligned_offset);
116
117 if (pbp->bitmap && !virtio_balloon_pbp_matches(pbp, base_gpa)) {
118
119
120
121 virtio_balloon_pbp_free(pbp);
122 }
123
124 if (!pbp->bitmap) {
125 virtio_balloon_pbp_alloc(pbp, base_gpa, subpages);
126 }
127
128 set_bit((rb_offset - rb_aligned_offset) / BALLOON_PAGE_SIZE,
129 pbp->bitmap);
130
131 if (bitmap_full(pbp->bitmap, subpages)) {
132
133
134
135 ram_block_discard_range(rb, rb_aligned_offset, rb_page_size);
136
137
138
139 virtio_balloon_pbp_free(pbp);
140 }
141}
142
143static void balloon_deflate_page(VirtIOBalloon *balloon,
144 MemoryRegion *mr, hwaddr mr_offset)
145{
146 void *addr = memory_region_get_ram_ptr(mr) + mr_offset;
147 ram_addr_t rb_offset;
148 RAMBlock *rb;
149 size_t rb_page_size;
150 void *host_addr;
151 int ret;
152
153
154
155 rb = qemu_ram_block_from_host(addr, false, &rb_offset);
156 rb_page_size = qemu_ram_pagesize(rb);
157
158 host_addr = (void *)((uintptr_t)addr & ~(rb_page_size - 1));
159
160
161
162 ret = qemu_madvise(host_addr, rb_page_size, QEMU_MADV_WILLNEED);
163 if (ret != 0) {
164 warn_report("Couldn't MADV_WILLNEED on balloon deflate: %s",
165 strerror(errno));
166
167 }
168}
169
170static const char *balloon_stat_names[] = {
171 [VIRTIO_BALLOON_S_SWAP_IN] = "stat-swap-in",
172 [VIRTIO_BALLOON_S_SWAP_OUT] = "stat-swap-out",
173 [VIRTIO_BALLOON_S_MAJFLT] = "stat-major-faults",
174 [VIRTIO_BALLOON_S_MINFLT] = "stat-minor-faults",
175 [VIRTIO_BALLOON_S_MEMFREE] = "stat-free-memory",
176 [VIRTIO_BALLOON_S_MEMTOT] = "stat-total-memory",
177 [VIRTIO_BALLOON_S_AVAIL] = "stat-available-memory",
178 [VIRTIO_BALLOON_S_CACHES] = "stat-disk-caches",
179 [VIRTIO_BALLOON_S_HTLB_PGALLOC] = "stat-htlb-pgalloc",
180 [VIRTIO_BALLOON_S_HTLB_PGFAIL] = "stat-htlb-pgfail",
181 [VIRTIO_BALLOON_S_NR] = NULL
182};
183
184
185
186
187
188
189
190
191
192static inline void reset_stats(VirtIOBalloon *dev)
193{
194 int i;
195 for (i = 0; i < VIRTIO_BALLOON_S_NR; dev->stats[i++] = -1);
196}
197
198static bool balloon_stats_supported(const VirtIOBalloon *s)
199{
200 VirtIODevice *vdev = VIRTIO_DEVICE(s);
201 return virtio_vdev_has_feature(vdev, VIRTIO_BALLOON_F_STATS_VQ);
202}
203
204static bool balloon_stats_enabled(const VirtIOBalloon *s)
205{
206 return s->stats_poll_interval > 0;
207}
208
209static void balloon_stats_destroy_timer(VirtIOBalloon *s)
210{
211 if (balloon_stats_enabled(s)) {
212 timer_free(s->stats_timer);
213 s->stats_timer = NULL;
214 s->stats_poll_interval = 0;
215 }
216}
217
218static void balloon_stats_change_timer(VirtIOBalloon *s, int64_t secs)
219{
220 timer_mod(s->stats_timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + secs * 1000);
221}
222
223static void balloon_stats_poll_cb(void *opaque)
224{
225 VirtIOBalloon *s = opaque;
226 VirtIODevice *vdev = VIRTIO_DEVICE(s);
227
228 if (s->stats_vq_elem == NULL || !balloon_stats_supported(s)) {
229
230 balloon_stats_change_timer(s, s->stats_poll_interval);
231 return;
232 }
233
234 virtqueue_push(s->svq, s->stats_vq_elem, s->stats_vq_offset);
235 virtio_notify(vdev, s->svq);
236 g_free(s->stats_vq_elem);
237 s->stats_vq_elem = NULL;
238}
239
240static void balloon_stats_get_all(Object *obj, Visitor *v, const char *name,
241 void *opaque, Error **errp)
242{
243 Error *err = NULL;
244 VirtIOBalloon *s = opaque;
245 int i;
246
247 if (!visit_start_struct(v, name, NULL, 0, &err)) {
248 goto out;
249 }
250 if (!visit_type_int(v, "last-update", &s->stats_last_update, &err)) {
251 goto out_end;
252 }
253
254 if (!visit_start_struct(v, "stats", NULL, 0, &err)) {
255 goto out_end;
256 }
257 for (i = 0; i < VIRTIO_BALLOON_S_NR; i++) {
258 if (!visit_type_uint64(v, balloon_stat_names[i], &s->stats[i], &err)) {
259 goto out_nested;
260 }
261 }
262 visit_check_struct(v, &err);
263out_nested:
264 visit_end_struct(v, NULL);
265
266 if (!err) {
267 visit_check_struct(v, &err);
268 }
269out_end:
270 visit_end_struct(v, NULL);
271out:
272 error_propagate(errp, err);
273}
274
275static void balloon_stats_get_poll_interval(Object *obj, Visitor *v,
276 const char *name, void *opaque,
277 Error **errp)
278{
279 VirtIOBalloon *s = opaque;
280 visit_type_int(v, name, &s->stats_poll_interval, errp);
281}
282
283static void balloon_stats_set_poll_interval(Object *obj, Visitor *v,
284 const char *name, void *opaque,
285 Error **errp)
286{
287 VirtIOBalloon *s = opaque;
288 int64_t value;
289
290 if (!visit_type_int(v, name, &value, errp)) {
291 return;
292 }
293
294 if (value < 0) {
295 error_setg(errp, "timer value must be greater than zero");
296 return;
297 }
298
299 if (value > UINT32_MAX) {
300 error_setg(errp, "timer value is too big");
301 return;
302 }
303
304 if (value == s->stats_poll_interval) {
305 return;
306 }
307
308 if (value == 0) {
309
310 balloon_stats_destroy_timer(s);
311 return;
312 }
313
314 if (balloon_stats_enabled(s)) {
315
316 s->stats_poll_interval = value;
317 balloon_stats_change_timer(s, value);
318 return;
319 }
320
321
322 g_assert(s->stats_timer == NULL);
323 s->stats_timer = timer_new_ms(QEMU_CLOCK_VIRTUAL, balloon_stats_poll_cb, s);
324 s->stats_poll_interval = value;
325 balloon_stats_change_timer(s, 0);
326}
327
328static void virtio_balloon_handle_report(VirtIODevice *vdev, VirtQueue *vq)
329{
330 VirtIOBalloon *dev = VIRTIO_BALLOON(vdev);
331 VirtQueueElement *elem;
332
333 while ((elem = virtqueue_pop(vq, sizeof(VirtQueueElement)))) {
334 unsigned int i;
335
336
337
338
339
340
341
342
343 if (virtio_balloon_inhibited() || dev->poison_val) {
344 goto skip_element;
345 }
346
347 for (i = 0; i < elem->in_num; i++) {
348 void *addr = elem->in_sg[i].iov_base;
349 size_t size = elem->in_sg[i].iov_len;
350 ram_addr_t ram_offset;
351 RAMBlock *rb;
352
353
354
355
356
357
358
359
360
361
362
363
364 rb = qemu_ram_block_from_host(addr, false, &ram_offset);
365 if (!rb) {
366 trace_virtio_balloon_bad_addr(elem->in_addr[i]);
367 continue;
368 }
369
370
371
372
373
374 if (!QEMU_IS_ALIGNED(ram_offset | size, qemu_ram_pagesize(rb)) ||
375 (ram_offset + size) > qemu_ram_get_used_length(rb)) {
376 continue;
377 }
378
379 ram_block_discard_range(rb, ram_offset, size);
380 }
381
382skip_element:
383 virtqueue_push(vq, elem, 0);
384 virtio_notify(vdev, vq);
385 g_free(elem);
386 }
387}
388
389static void virtio_balloon_handle_output(VirtIODevice *vdev, VirtQueue *vq)
390{
391 VirtIOBalloon *s = VIRTIO_BALLOON(vdev);
392 VirtQueueElement *elem;
393 MemoryRegionSection section;
394
395 for (;;) {
396 PartiallyBalloonedPage pbp = {};
397 size_t offset = 0;
398 uint32_t pfn;
399
400 elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
401 if (!elem) {
402 break;
403 }
404
405 while (iov_to_buf(elem->out_sg, elem->out_num, offset, &pfn, 4) == 4) {
406 unsigned int p = virtio_ldl_p(vdev, &pfn);
407 hwaddr pa;
408
409 pa = (hwaddr) p << VIRTIO_BALLOON_PFN_SHIFT;
410 offset += 4;
411
412 section = memory_region_find(get_system_memory(), pa,
413 BALLOON_PAGE_SIZE);
414 if (!section.mr) {
415 trace_virtio_balloon_bad_addr(pa);
416 continue;
417 }
418 if (!memory_region_is_ram(section.mr) ||
419 memory_region_is_rom(section.mr) ||
420 memory_region_is_romd(section.mr)) {
421 trace_virtio_balloon_bad_addr(pa);
422 memory_region_unref(section.mr);
423 continue;
424 }
425
426 trace_virtio_balloon_handle_output(memory_region_name(section.mr),
427 pa);
428 if (!virtio_balloon_inhibited()) {
429 if (vq == s->ivq) {
430 balloon_inflate_page(s, section.mr,
431 section.offset_within_region, &pbp);
432 } else if (vq == s->dvq) {
433 balloon_deflate_page(s, section.mr, section.offset_within_region);
434 } else {
435 g_assert_not_reached();
436 }
437 }
438 memory_region_unref(section.mr);
439 }
440
441 virtqueue_push(vq, elem, offset);
442 virtio_notify(vdev, vq);
443 g_free(elem);
444 virtio_balloon_pbp_free(&pbp);
445 }
446}
447
448static void virtio_balloon_receive_stats(VirtIODevice *vdev, VirtQueue *vq)
449{
450 VirtIOBalloon *s = VIRTIO_BALLOON(vdev);
451 VirtQueueElement *elem;
452 VirtIOBalloonStat stat;
453 size_t offset = 0;
454 qemu_timeval tv;
455
456 elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
457 if (!elem) {
458 goto out;
459 }
460
461 if (s->stats_vq_elem != NULL) {
462
463 virtqueue_push(vq, s->stats_vq_elem, 0);
464 virtio_notify(vdev, vq);
465 g_free(s->stats_vq_elem);
466 }
467
468 s->stats_vq_elem = elem;
469
470
471
472
473
474 reset_stats(s);
475
476 while (iov_to_buf(elem->out_sg, elem->out_num, offset, &stat, sizeof(stat))
477 == sizeof(stat)) {
478 uint16_t tag = virtio_tswap16(vdev, stat.tag);
479 uint64_t val = virtio_tswap64(vdev, stat.val);
480
481 offset += sizeof(stat);
482 if (tag < VIRTIO_BALLOON_S_NR)
483 s->stats[tag] = val;
484 }
485 s->stats_vq_offset = offset;
486
487 if (qemu_gettimeofday(&tv) < 0) {
488 warn_report("%s: failed to get time of day", __func__);
489 goto out;
490 }
491
492 s->stats_last_update = tv.tv_sec;
493
494out:
495 if (balloon_stats_enabled(s)) {
496 balloon_stats_change_timer(s, s->stats_poll_interval);
497 }
498}
499
500static void virtio_balloon_handle_free_page_vq(VirtIODevice *vdev,
501 VirtQueue *vq)
502{
503 VirtIOBalloon *s = VIRTIO_BALLOON(vdev);
504 qemu_bh_schedule(s->free_page_bh);
505}
506
507static bool get_free_page_hints(VirtIOBalloon *dev)
508{
509 VirtQueueElement *elem;
510 VirtIODevice *vdev = VIRTIO_DEVICE(dev);
511 VirtQueue *vq = dev->free_page_vq;
512 bool ret = true;
513
514 while (dev->block_iothread) {
515 qemu_cond_wait(&dev->free_page_cond, &dev->free_page_lock);
516 }
517
518 elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
519 if (!elem) {
520 return false;
521 }
522
523 if (elem->out_num) {
524 uint32_t id;
525 size_t size = iov_to_buf(elem->out_sg, elem->out_num, 0,
526 &id, sizeof(id));
527
528 virtio_tswap32s(vdev, &id);
529 if (unlikely(size != sizeof(id))) {
530 virtio_error(vdev, "received an incorrect cmd id");
531 ret = false;
532 goto out;
533 }
534 if (dev->free_page_hint_status == FREE_PAGE_HINT_S_REQUESTED &&
535 id == dev->free_page_hint_cmd_id) {
536 dev->free_page_hint_status = FREE_PAGE_HINT_S_START;
537 } else {
538
539
540
541
542 if (dev->free_page_hint_status == FREE_PAGE_HINT_S_START) {
543 dev->free_page_hint_status = FREE_PAGE_HINT_S_STOP;
544 }
545 }
546 }
547
548 if (elem->in_num) {
549 if (dev->free_page_hint_status == FREE_PAGE_HINT_S_START) {
550 qemu_guest_free_page_hint(elem->in_sg[0].iov_base,
551 elem->in_sg[0].iov_len);
552 }
553 }
554
555out:
556 virtqueue_push(vq, elem, 1);
557 g_free(elem);
558 return ret;
559}
560
561static void virtio_ballloon_get_free_page_hints(void *opaque)
562{
563 VirtIOBalloon *dev = opaque;
564 VirtIODevice *vdev = VIRTIO_DEVICE(dev);
565 VirtQueue *vq = dev->free_page_vq;
566 bool continue_to_get_hints;
567
568 do {
569 qemu_mutex_lock(&dev->free_page_lock);
570 virtio_queue_set_notification(vq, 0);
571 continue_to_get_hints = get_free_page_hints(dev);
572 qemu_mutex_unlock(&dev->free_page_lock);
573 virtio_notify(vdev, vq);
574
575
576
577
578 } while (continue_to_get_hints ||
579 dev->free_page_hint_status == FREE_PAGE_HINT_S_START);
580 virtio_queue_set_notification(vq, 1);
581}
582
583static bool virtio_balloon_free_page_support(void *opaque)
584{
585 VirtIOBalloon *s = opaque;
586 VirtIODevice *vdev = VIRTIO_DEVICE(s);
587
588 return virtio_vdev_has_feature(vdev, VIRTIO_BALLOON_F_FREE_PAGE_HINT);
589}
590
591static void virtio_balloon_free_page_start(VirtIOBalloon *s)
592{
593 VirtIODevice *vdev = VIRTIO_DEVICE(s);
594
595
596 if (!vdev->vm_running) {
597 return;
598 }
599
600 qemu_mutex_lock(&s->free_page_lock);
601
602 if (s->free_page_hint_cmd_id == UINT_MAX) {
603 s->free_page_hint_cmd_id =
604 VIRTIO_BALLOON_FREE_PAGE_HINT_CMD_ID_MIN;
605 } else {
606 s->free_page_hint_cmd_id++;
607 }
608
609 s->free_page_hint_status = FREE_PAGE_HINT_S_REQUESTED;
610 qemu_mutex_unlock(&s->free_page_lock);
611
612 virtio_notify_config(vdev);
613}
614
615static void virtio_balloon_free_page_stop(VirtIOBalloon *s)
616{
617 VirtIODevice *vdev = VIRTIO_DEVICE(s);
618
619 if (s->free_page_hint_status != FREE_PAGE_HINT_S_STOP) {
620
621
622
623
624
625 qemu_mutex_lock(&s->free_page_lock);
626
627
628
629
630 s->free_page_hint_status = FREE_PAGE_HINT_S_STOP;
631 qemu_mutex_unlock(&s->free_page_lock);
632 virtio_notify_config(vdev);
633 }
634}
635
636static void virtio_balloon_free_page_done(VirtIOBalloon *s)
637{
638 VirtIODevice *vdev = VIRTIO_DEVICE(s);
639
640 if (s->free_page_hint_status != FREE_PAGE_HINT_S_DONE) {
641
642 qemu_mutex_lock(&s->free_page_lock);
643 s->free_page_hint_status = FREE_PAGE_HINT_S_DONE;
644 qemu_mutex_unlock(&s->free_page_lock);
645 virtio_notify_config(vdev);
646 }
647}
648
649static int
650virtio_balloon_free_page_hint_notify(NotifierWithReturn *n, void *data)
651{
652 VirtIOBalloon *dev = container_of(n, VirtIOBalloon,
653 free_page_hint_notify);
654 VirtIODevice *vdev = VIRTIO_DEVICE(dev);
655 PrecopyNotifyData *pnd = data;
656
657 if (!virtio_balloon_free_page_support(dev)) {
658
659
660
661
662
663 return 0;
664 }
665
666
667
668
669
670
671
672
673
674 if (migrate_postcopy_ram()) {
675 return 0;
676 }
677
678 switch (pnd->reason) {
679 case PRECOPY_NOTIFY_SETUP:
680 precopy_enable_free_page_optimization();
681 break;
682 case PRECOPY_NOTIFY_BEFORE_BITMAP_SYNC:
683 virtio_balloon_free_page_stop(dev);
684 break;
685 case PRECOPY_NOTIFY_AFTER_BITMAP_SYNC:
686 if (vdev->vm_running) {
687 virtio_balloon_free_page_start(dev);
688 break;
689 }
690
691
692
693
694 case PRECOPY_NOTIFY_CLEANUP:
695
696
697
698
699 virtio_balloon_free_page_done(dev);
700 break;
701 case PRECOPY_NOTIFY_COMPLETE:
702 break;
703 default:
704 virtio_error(vdev, "%s: %d reason unknown", __func__, pnd->reason);
705 }
706
707 return 0;
708}
709
710static size_t virtio_balloon_config_size(VirtIOBalloon *s)
711{
712 uint64_t features = s->host_features;
713
714 if (s->qemu_4_0_config_size) {
715 return sizeof(struct virtio_balloon_config);
716 }
717 if (virtio_has_feature(features, VIRTIO_BALLOON_F_PAGE_POISON)) {
718 return sizeof(struct virtio_balloon_config);
719 }
720 if (virtio_has_feature(features, VIRTIO_BALLOON_F_FREE_PAGE_HINT)) {
721 return offsetof(struct virtio_balloon_config, poison_val);
722 }
723 return offsetof(struct virtio_balloon_config, free_page_hint_cmd_id);
724}
725
726static void virtio_balloon_get_config(VirtIODevice *vdev, uint8_t *config_data)
727{
728 VirtIOBalloon *dev = VIRTIO_BALLOON(vdev);
729 struct virtio_balloon_config config = {};
730
731 config.num_pages = cpu_to_le32(dev->num_pages);
732 config.actual = cpu_to_le32(dev->actual);
733 config.poison_val = cpu_to_le32(dev->poison_val);
734
735 if (dev->free_page_hint_status == FREE_PAGE_HINT_S_REQUESTED) {
736 config.free_page_hint_cmd_id =
737 cpu_to_le32(dev->free_page_hint_cmd_id);
738 } else if (dev->free_page_hint_status == FREE_PAGE_HINT_S_STOP) {
739 config.free_page_hint_cmd_id =
740 cpu_to_le32(VIRTIO_BALLOON_CMD_ID_STOP);
741 } else if (dev->free_page_hint_status == FREE_PAGE_HINT_S_DONE) {
742 config.free_page_hint_cmd_id =
743 cpu_to_le32(VIRTIO_BALLOON_CMD_ID_DONE);
744 }
745
746 trace_virtio_balloon_get_config(config.num_pages, config.actual);
747 memcpy(config_data, &config, virtio_balloon_config_size(dev));
748}
749
750static int build_dimm_list(Object *obj, void *opaque)
751{
752 GSList **list = opaque;
753
754 if (object_dynamic_cast(obj, TYPE_PC_DIMM)) {
755 DeviceState *dev = DEVICE(obj);
756 if (dev->realized) {
757 *list = g_slist_prepend(*list, dev);
758 }
759 }
760
761 object_child_foreach(obj, build_dimm_list, opaque);
762 return 0;
763}
764
765static ram_addr_t get_current_ram_size(void)
766{
767 GSList *list = NULL, *item;
768 ram_addr_t size = current_machine->ram_size;
769
770 build_dimm_list(qdev_get_machine(), &list);
771 for (item = list; item; item = g_slist_next(item)) {
772 Object *obj = OBJECT(item->data);
773 if (!strcmp(object_get_typename(obj), TYPE_PC_DIMM)) {
774 size += object_property_get_int(obj, PC_DIMM_SIZE_PROP,
775 &error_abort);
776 }
777 }
778 g_slist_free(list);
779
780 return size;
781}
782
783static bool virtio_balloon_page_poison_support(void *opaque)
784{
785 VirtIOBalloon *s = opaque;
786 VirtIODevice *vdev = VIRTIO_DEVICE(s);
787
788 return virtio_vdev_has_feature(vdev, VIRTIO_BALLOON_F_PAGE_POISON);
789}
790
791static void virtio_balloon_set_config(VirtIODevice *vdev,
792 const uint8_t *config_data)
793{
794 VirtIOBalloon *dev = VIRTIO_BALLOON(vdev);
795 struct virtio_balloon_config config;
796 uint32_t oldactual = dev->actual;
797 ram_addr_t vm_ram_size = get_current_ram_size();
798
799 memcpy(&config, config_data, virtio_balloon_config_size(dev));
800 dev->actual = le32_to_cpu(config.actual);
801 if (dev->actual != oldactual) {
802 qapi_event_send_balloon_change(vm_ram_size -
803 ((ram_addr_t) dev->actual << VIRTIO_BALLOON_PFN_SHIFT));
804 }
805 dev->poison_val = 0;
806 if (virtio_balloon_page_poison_support(dev)) {
807 dev->poison_val = le32_to_cpu(config.poison_val);
808 }
809 trace_virtio_balloon_set_config(dev->actual, oldactual);
810}
811
812static uint64_t virtio_balloon_get_features(VirtIODevice *vdev, uint64_t f,
813 Error **errp)
814{
815 VirtIOBalloon *dev = VIRTIO_BALLOON(vdev);
816 f |= dev->host_features;
817 virtio_add_feature(&f, VIRTIO_BALLOON_F_STATS_VQ);
818
819 return f;
820}
821
822static void virtio_balloon_stat(void *opaque, BalloonInfo *info)
823{
824 VirtIOBalloon *dev = opaque;
825 info->actual = get_current_ram_size() - ((uint64_t) dev->actual <<
826 VIRTIO_BALLOON_PFN_SHIFT);
827}
828
829static void virtio_balloon_to_target(void *opaque, ram_addr_t target)
830{
831 VirtIOBalloon *dev = VIRTIO_BALLOON(opaque);
832 VirtIODevice *vdev = VIRTIO_DEVICE(dev);
833 ram_addr_t vm_ram_size = get_current_ram_size();
834
835 if (target > vm_ram_size) {
836 target = vm_ram_size;
837 }
838 if (target) {
839 dev->num_pages = (vm_ram_size - target) >> VIRTIO_BALLOON_PFN_SHIFT;
840 virtio_notify_config(vdev);
841 }
842 trace_virtio_balloon_to_target(target, dev->num_pages);
843}
844
845static int virtio_balloon_post_load_device(void *opaque, int version_id)
846{
847 VirtIOBalloon *s = VIRTIO_BALLOON(opaque);
848
849 if (balloon_stats_enabled(s)) {
850 balloon_stats_change_timer(s, s->stats_poll_interval);
851 }
852 return 0;
853}
854
855static const VMStateDescription vmstate_virtio_balloon_free_page_hint = {
856 .name = "virtio-balloon-device/free-page-report",
857 .version_id = 1,
858 .minimum_version_id = 1,
859 .needed = virtio_balloon_free_page_support,
860 .fields = (VMStateField[]) {
861 VMSTATE_UINT32(free_page_hint_cmd_id, VirtIOBalloon),
862 VMSTATE_UINT32(free_page_hint_status, VirtIOBalloon),
863 VMSTATE_END_OF_LIST()
864 }
865};
866
867static const VMStateDescription vmstate_virtio_balloon_page_poison = {
868 .name = "vitio-balloon-device/page-poison",
869 .version_id = 1,
870 .minimum_version_id = 1,
871 .needed = virtio_balloon_page_poison_support,
872 .fields = (VMStateField[]) {
873 VMSTATE_UINT32(poison_val, VirtIOBalloon),
874 VMSTATE_END_OF_LIST()
875 }
876};
877
878static const VMStateDescription vmstate_virtio_balloon_device = {
879 .name = "virtio-balloon-device",
880 .version_id = 1,
881 .minimum_version_id = 1,
882 .post_load = virtio_balloon_post_load_device,
883 .fields = (VMStateField[]) {
884 VMSTATE_UINT32(num_pages, VirtIOBalloon),
885 VMSTATE_UINT32(actual, VirtIOBalloon),
886 VMSTATE_END_OF_LIST()
887 },
888 .subsections = (const VMStateDescription * []) {
889 &vmstate_virtio_balloon_free_page_hint,
890 &vmstate_virtio_balloon_page_poison,
891 NULL
892 }
893};
894
895static void virtio_balloon_device_realize(DeviceState *dev, Error **errp)
896{
897 VirtIODevice *vdev = VIRTIO_DEVICE(dev);
898 VirtIOBalloon *s = VIRTIO_BALLOON(dev);
899 int ret;
900
901 virtio_init(vdev, "virtio-balloon", VIRTIO_ID_BALLOON,
902 virtio_balloon_config_size(s));
903
904 ret = qemu_add_balloon_handler(virtio_balloon_to_target,
905 virtio_balloon_stat, s);
906
907 if (ret < 0) {
908 error_setg(errp, "Only one balloon device is supported");
909 virtio_cleanup(vdev);
910 return;
911 }
912
913 if (virtio_has_feature(s->host_features, VIRTIO_BALLOON_F_FREE_PAGE_HINT) &&
914 !s->iothread) {
915 error_setg(errp, "'free-page-hint' requires 'iothread' to be set");
916 virtio_cleanup(vdev);
917 return;
918 }
919
920 s->ivq = virtio_add_queue(vdev, 128, virtio_balloon_handle_output);
921 s->dvq = virtio_add_queue(vdev, 128, virtio_balloon_handle_output);
922 s->svq = virtio_add_queue(vdev, 128, virtio_balloon_receive_stats);
923
924 if (virtio_has_feature(s->host_features,
925 VIRTIO_BALLOON_F_FREE_PAGE_HINT)) {
926 s->free_page_vq = virtio_add_queue(vdev, VIRTQUEUE_MAX_SIZE,
927 virtio_balloon_handle_free_page_vq);
928 precopy_add_notifier(&s->free_page_hint_notify);
929
930 object_ref(OBJECT(s->iothread));
931 s->free_page_bh = aio_bh_new(iothread_get_aio_context(s->iothread),
932 virtio_ballloon_get_free_page_hints, s);
933 }
934
935 if (virtio_has_feature(s->host_features, VIRTIO_BALLOON_F_REPORTING)) {
936 s->reporting_vq = virtio_add_queue(vdev, 32,
937 virtio_balloon_handle_report);
938 }
939
940 reset_stats(s);
941}
942
943static void virtio_balloon_device_unrealize(DeviceState *dev)
944{
945 VirtIODevice *vdev = VIRTIO_DEVICE(dev);
946 VirtIOBalloon *s = VIRTIO_BALLOON(dev);
947
948 if (s->free_page_bh) {
949 qemu_bh_delete(s->free_page_bh);
950 object_unref(OBJECT(s->iothread));
951 virtio_balloon_free_page_stop(s);
952 precopy_remove_notifier(&s->free_page_hint_notify);
953 }
954 balloon_stats_destroy_timer(s);
955 qemu_remove_balloon_handler(s);
956
957 virtio_delete_queue(s->ivq);
958 virtio_delete_queue(s->dvq);
959 virtio_delete_queue(s->svq);
960 if (s->free_page_vq) {
961 virtio_delete_queue(s->free_page_vq);
962 }
963 if (s->reporting_vq) {
964 virtio_delete_queue(s->reporting_vq);
965 }
966 virtio_cleanup(vdev);
967}
968
969static void virtio_balloon_device_reset(VirtIODevice *vdev)
970{
971 VirtIOBalloon *s = VIRTIO_BALLOON(vdev);
972
973 if (virtio_balloon_free_page_support(s)) {
974 virtio_balloon_free_page_stop(s);
975 }
976
977 if (s->stats_vq_elem != NULL) {
978 virtqueue_unpop(s->svq, s->stats_vq_elem, 0);
979 g_free(s->stats_vq_elem);
980 s->stats_vq_elem = NULL;
981 }
982
983 s->poison_val = 0;
984}
985
986static void virtio_balloon_set_status(VirtIODevice *vdev, uint8_t status)
987{
988 VirtIOBalloon *s = VIRTIO_BALLOON(vdev);
989
990 if (!s->stats_vq_elem && vdev->vm_running &&
991 (status & VIRTIO_CONFIG_S_DRIVER_OK) && virtqueue_rewind(s->svq, 1)) {
992
993
994 virtio_balloon_receive_stats(vdev, s->svq);
995 }
996
997 if (virtio_balloon_free_page_support(s)) {
998
999
1000
1001
1002 if (vdev->vm_running && s->block_iothread) {
1003 qemu_mutex_lock(&s->free_page_lock);
1004 s->block_iothread = false;
1005 qemu_cond_signal(&s->free_page_cond);
1006 qemu_mutex_unlock(&s->free_page_lock);
1007 }
1008
1009
1010 if (!vdev->vm_running) {
1011 qemu_mutex_lock(&s->free_page_lock);
1012 s->block_iothread = true;
1013 qemu_mutex_unlock(&s->free_page_lock);
1014 }
1015 }
1016}
1017
1018static void virtio_balloon_instance_init(Object *obj)
1019{
1020 VirtIOBalloon *s = VIRTIO_BALLOON(obj);
1021
1022 qemu_mutex_init(&s->free_page_lock);
1023 qemu_cond_init(&s->free_page_cond);
1024 s->free_page_hint_cmd_id = VIRTIO_BALLOON_FREE_PAGE_HINT_CMD_ID_MIN;
1025 s->free_page_hint_notify.notify = virtio_balloon_free_page_hint_notify;
1026
1027 object_property_add(obj, "guest-stats", "guest statistics",
1028 balloon_stats_get_all, NULL, NULL, s);
1029
1030 object_property_add(obj, "guest-stats-polling-interval", "int",
1031 balloon_stats_get_poll_interval,
1032 balloon_stats_set_poll_interval,
1033 NULL, s);
1034}
1035
1036static const VMStateDescription vmstate_virtio_balloon = {
1037 .name = "virtio-balloon",
1038 .minimum_version_id = 1,
1039 .version_id = 1,
1040 .fields = (VMStateField[]) {
1041 VMSTATE_VIRTIO_DEVICE,
1042 VMSTATE_END_OF_LIST()
1043 },
1044};
1045
1046static Property virtio_balloon_properties[] = {
1047 DEFINE_PROP_BIT("deflate-on-oom", VirtIOBalloon, host_features,
1048 VIRTIO_BALLOON_F_DEFLATE_ON_OOM, false),
1049 DEFINE_PROP_BIT("free-page-hint", VirtIOBalloon, host_features,
1050 VIRTIO_BALLOON_F_FREE_PAGE_HINT, false),
1051 DEFINE_PROP_BIT("page-poison", VirtIOBalloon, host_features,
1052 VIRTIO_BALLOON_F_PAGE_POISON, true),
1053 DEFINE_PROP_BIT("free-page-reporting", VirtIOBalloon, host_features,
1054 VIRTIO_BALLOON_F_REPORTING, false),
1055
1056
1057
1058
1059 DEFINE_PROP_BOOL("qemu-4-0-config-size", VirtIOBalloon,
1060 qemu_4_0_config_size, false),
1061 DEFINE_PROP_LINK("iothread", VirtIOBalloon, iothread, TYPE_IOTHREAD,
1062 IOThread *),
1063 DEFINE_PROP_END_OF_LIST(),
1064};
1065
1066static void virtio_balloon_class_init(ObjectClass *klass, void *data)
1067{
1068 DeviceClass *dc = DEVICE_CLASS(klass);
1069 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
1070
1071 device_class_set_props(dc, virtio_balloon_properties);
1072 dc->vmsd = &vmstate_virtio_balloon;
1073 set_bit(DEVICE_CATEGORY_MISC, dc->categories);
1074 vdc->realize = virtio_balloon_device_realize;
1075 vdc->unrealize = virtio_balloon_device_unrealize;
1076 vdc->reset = virtio_balloon_device_reset;
1077 vdc->get_config = virtio_balloon_get_config;
1078 vdc->set_config = virtio_balloon_set_config;
1079 vdc->get_features = virtio_balloon_get_features;
1080 vdc->set_status = virtio_balloon_set_status;
1081 vdc->vmsd = &vmstate_virtio_balloon_device;
1082}
1083
1084static const TypeInfo virtio_balloon_info = {
1085 .name = TYPE_VIRTIO_BALLOON,
1086 .parent = TYPE_VIRTIO_DEVICE,
1087 .instance_size = sizeof(VirtIOBalloon),
1088 .instance_init = virtio_balloon_instance_init,
1089 .class_init = virtio_balloon_class_init,
1090};
1091
1092static void virtio_register_types(void)
1093{
1094 type_register_static(&virtio_balloon_info);
1095}
1096
1097type_init(virtio_register_types)
1098