virtio-balloon: rewrite get_current_ram_size()
[qemu/cris-port.git] / hw / virtio / virtio-balloon.c
blob388e87336a58e5b96cc61f6ba40d536434bdd154
1 /*
2 * Virtio Balloon Device
4 * Copyright IBM, Corp. 2008
5 * Copyright (C) 2011 Red Hat, Inc.
6 * Copyright (C) 2011 Amit Shah <amit.shah@redhat.com>
8 * Authors:
9 * Anthony Liguori <aliguori@us.ibm.com>
11 * This work is licensed under the terms of the GNU GPL, version 2. See
12 * the COPYING file in the top-level directory.
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 "cpu.h"
23 #include "sysemu/balloon.h"
24 #include "hw/virtio/virtio-balloon.h"
25 #include "sysemu/kvm.h"
26 #include "exec/address-spaces.h"
27 #include "qapi/visitor.h"
28 #include "qapi-event.h"
29 #include "trace.h"
31 #if defined(__linux__)
32 #include <sys/mman.h>
33 #endif
35 #include "hw/virtio/virtio-bus.h"
36 #include "hw/virtio/virtio-access.h"
38 static void balloon_page(void *addr, int deflate)
40 #if defined(__linux__)
41 if (!qemu_balloon_is_inhibited() && (!kvm_enabled() ||
42 kvm_has_sync_mmu())) {
43 qemu_madvise(addr, TARGET_PAGE_SIZE,
44 deflate ? QEMU_MADV_WILLNEED : QEMU_MADV_DONTNEED);
46 #endif
49 static const char *balloon_stat_names[] = {
50 [VIRTIO_BALLOON_S_SWAP_IN] = "stat-swap-in",
51 [VIRTIO_BALLOON_S_SWAP_OUT] = "stat-swap-out",
52 [VIRTIO_BALLOON_S_MAJFLT] = "stat-major-faults",
53 [VIRTIO_BALLOON_S_MINFLT] = "stat-minor-faults",
54 [VIRTIO_BALLOON_S_MEMFREE] = "stat-free-memory",
55 [VIRTIO_BALLOON_S_MEMTOT] = "stat-total-memory",
56 [VIRTIO_BALLOON_S_NR] = NULL
60 * reset_stats - Mark all items in the stats array as unset
62 * This function needs to be called at device initialization and before
63 * updating to a set of newly-generated stats. This will ensure that no
64 * stale values stick around in case the guest reports a subset of the supported
65 * statistics.
67 static inline void reset_stats(VirtIOBalloon *dev)
69 int i;
70 for (i = 0; i < VIRTIO_BALLOON_S_NR; dev->stats[i++] = -1);
73 static bool balloon_stats_supported(const VirtIOBalloon *s)
75 VirtIODevice *vdev = VIRTIO_DEVICE(s);
76 return virtio_vdev_has_feature(vdev, VIRTIO_BALLOON_F_STATS_VQ);
79 static bool balloon_stats_enabled(const VirtIOBalloon *s)
81 return s->stats_poll_interval > 0;
84 static void balloon_stats_destroy_timer(VirtIOBalloon *s)
86 if (balloon_stats_enabled(s)) {
87 timer_del(s->stats_timer);
88 timer_free(s->stats_timer);
89 s->stats_timer = NULL;
90 s->stats_poll_interval = 0;
94 static void balloon_stats_change_timer(VirtIOBalloon *s, int64_t secs)
96 timer_mod(s->stats_timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + secs * 1000);
99 static void balloon_stats_poll_cb(void *opaque)
101 VirtIOBalloon *s = opaque;
102 VirtIODevice *vdev = VIRTIO_DEVICE(s);
104 if (!balloon_stats_supported(s)) {
105 /* re-schedule */
106 balloon_stats_change_timer(s, s->stats_poll_interval);
107 return;
110 virtqueue_push(s->svq, s->stats_vq_elem, s->stats_vq_offset);
111 virtio_notify(vdev, s->svq);
112 g_free(s->stats_vq_elem);
113 s->stats_vq_elem = NULL;
116 static void balloon_stats_get_all(Object *obj, Visitor *v, const char *name,
117 void *opaque, Error **errp)
119 Error *err = NULL;
120 VirtIOBalloon *s = opaque;
121 int i;
123 visit_start_struct(v, name, NULL, 0, &err);
124 if (err) {
125 goto out;
127 visit_type_int(v, "last-update", &s->stats_last_update, &err);
128 if (err) {
129 goto out_end;
132 visit_start_struct(v, "stats", NULL, 0, &err);
133 if (err) {
134 goto out_end;
136 for (i = 0; i < VIRTIO_BALLOON_S_NR; i++) {
137 visit_type_uint64(v, balloon_stat_names[i], &s->stats[i], &err);
138 if (err) {
139 break;
142 error_propagate(errp, err);
143 err = NULL;
144 visit_end_struct(v, &err);
146 out_end:
147 error_propagate(errp, err);
148 err = NULL;
149 visit_end_struct(v, &err);
150 out:
151 error_propagate(errp, err);
154 static void balloon_stats_get_poll_interval(Object *obj, Visitor *v,
155 const char *name, void *opaque,
156 Error **errp)
158 VirtIOBalloon *s = opaque;
159 visit_type_int(v, name, &s->stats_poll_interval, errp);
162 static void balloon_stats_set_poll_interval(Object *obj, Visitor *v,
163 const char *name, void *opaque,
164 Error **errp)
166 VirtIOBalloon *s = opaque;
167 Error *local_err = NULL;
168 int64_t value;
170 visit_type_int(v, name, &value, &local_err);
171 if (local_err) {
172 error_propagate(errp, local_err);
173 return;
176 if (value < 0) {
177 error_setg(errp, "timer value must be greater than zero");
178 return;
181 if (value > UINT32_MAX) {
182 error_setg(errp, "timer value is too big");
183 return;
186 if (value == s->stats_poll_interval) {
187 return;
190 if (value == 0) {
191 /* timer=0 disables the timer */
192 balloon_stats_destroy_timer(s);
193 return;
196 if (balloon_stats_enabled(s)) {
197 /* timer interval change */
198 s->stats_poll_interval = value;
199 balloon_stats_change_timer(s, value);
200 return;
203 /* create a new timer */
204 g_assert(s->stats_timer == NULL);
205 s->stats_timer = timer_new_ms(QEMU_CLOCK_VIRTUAL, balloon_stats_poll_cb, s);
206 s->stats_poll_interval = value;
207 balloon_stats_change_timer(s, 0);
210 static void virtio_balloon_handle_output(VirtIODevice *vdev, VirtQueue *vq)
212 VirtIOBalloon *s = VIRTIO_BALLOON(vdev);
213 VirtQueueElement *elem;
214 MemoryRegionSection section;
216 for (;;) {
217 size_t offset = 0;
218 uint32_t pfn;
219 elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
220 if (!elem) {
221 return;
224 while (iov_to_buf(elem->out_sg, elem->out_num, offset, &pfn, 4) == 4) {
225 ram_addr_t pa;
226 ram_addr_t addr;
227 int p = virtio_ldl_p(vdev, &pfn);
229 pa = (ram_addr_t) p << VIRTIO_BALLOON_PFN_SHIFT;
230 offset += 4;
232 /* FIXME: remove get_system_memory(), but how? */
233 section = memory_region_find(get_system_memory(), pa, 1);
234 if (!int128_nz(section.size) || !memory_region_is_ram(section.mr))
235 continue;
237 trace_virtio_balloon_handle_output(memory_region_name(section.mr),
238 pa);
239 /* Using memory_region_get_ram_ptr is bending the rules a bit, but
240 should be OK because we only want a single page. */
241 addr = section.offset_within_region;
242 balloon_page(memory_region_get_ram_ptr(section.mr) + addr,
243 !!(vq == s->dvq));
244 memory_region_unref(section.mr);
247 virtqueue_push(vq, elem, offset);
248 virtio_notify(vdev, vq);
249 g_free(elem);
253 static void virtio_balloon_receive_stats(VirtIODevice *vdev, VirtQueue *vq)
255 VirtIOBalloon *s = VIRTIO_BALLOON(vdev);
256 VirtQueueElement *elem;
257 VirtIOBalloonStat stat;
258 size_t offset = 0;
259 qemu_timeval tv;
261 s->stats_vq_elem = elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
262 if (!elem) {
263 goto out;
266 /* Initialize the stats to get rid of any stale values. This is only
267 * needed to handle the case where a guest supports fewer stats than it
268 * used to (ie. it has booted into an old kernel).
270 reset_stats(s);
272 while (iov_to_buf(elem->out_sg, elem->out_num, offset, &stat, sizeof(stat))
273 == sizeof(stat)) {
274 uint16_t tag = virtio_tswap16(vdev, stat.tag);
275 uint64_t val = virtio_tswap64(vdev, stat.val);
277 offset += sizeof(stat);
278 if (tag < VIRTIO_BALLOON_S_NR)
279 s->stats[tag] = val;
281 s->stats_vq_offset = offset;
283 if (qemu_gettimeofday(&tv) < 0) {
284 fprintf(stderr, "warning: %s: failed to get time of day\n", __func__);
285 goto out;
288 s->stats_last_update = tv.tv_sec;
290 out:
291 if (balloon_stats_enabled(s)) {
292 balloon_stats_change_timer(s, s->stats_poll_interval);
296 static void virtio_balloon_get_config(VirtIODevice *vdev, uint8_t *config_data)
298 VirtIOBalloon *dev = VIRTIO_BALLOON(vdev);
299 struct virtio_balloon_config config;
301 config.num_pages = cpu_to_le32(dev->num_pages);
302 config.actual = cpu_to_le32(dev->actual);
304 trace_virtio_balloon_get_config(config.num_pages, config.actual);
305 memcpy(config_data, &config, sizeof(struct virtio_balloon_config));
308 static ram_addr_t get_current_ram_size(void)
310 GSList *list = NULL, *item;
311 ram_addr_t size = ram_size;
313 pc_dimm_build_list(qdev_get_machine(), &list);
314 for (item = list; item; item = g_slist_next(item)) {
315 Object *obj = OBJECT(item->data);
316 size += object_property_get_int(obj, PC_DIMM_SIZE_PROP, &error_abort);
318 g_slist_free(list);
320 return size;
323 static void virtio_balloon_set_config(VirtIODevice *vdev,
324 const uint8_t *config_data)
326 VirtIOBalloon *dev = VIRTIO_BALLOON(vdev);
327 struct virtio_balloon_config config;
328 uint32_t oldactual = dev->actual;
329 ram_addr_t vm_ram_size = get_current_ram_size();
331 memcpy(&config, config_data, sizeof(struct virtio_balloon_config));
332 dev->actual = le32_to_cpu(config.actual);
333 if (dev->actual != oldactual) {
334 qapi_event_send_balloon_change(vm_ram_size -
335 ((ram_addr_t) dev->actual << VIRTIO_BALLOON_PFN_SHIFT),
336 &error_abort);
338 trace_virtio_balloon_set_config(dev->actual, oldactual);
341 static uint64_t virtio_balloon_get_features(VirtIODevice *vdev, uint64_t f,
342 Error **errp)
344 VirtIOBalloon *dev = VIRTIO_BALLOON(vdev);
345 f |= dev->host_features;
346 virtio_add_feature(&f, VIRTIO_BALLOON_F_STATS_VQ);
347 return f;
350 static void virtio_balloon_stat(void *opaque, BalloonInfo *info)
352 VirtIOBalloon *dev = opaque;
353 info->actual = get_current_ram_size() - ((uint64_t) dev->actual <<
354 VIRTIO_BALLOON_PFN_SHIFT);
357 static void virtio_balloon_to_target(void *opaque, ram_addr_t target)
359 VirtIOBalloon *dev = VIRTIO_BALLOON(opaque);
360 VirtIODevice *vdev = VIRTIO_DEVICE(dev);
361 ram_addr_t vm_ram_size = get_current_ram_size();
363 if (target > vm_ram_size) {
364 target = vm_ram_size;
366 if (target) {
367 dev->num_pages = (vm_ram_size - target) >> VIRTIO_BALLOON_PFN_SHIFT;
368 virtio_notify_config(vdev);
370 trace_virtio_balloon_to_target(target, dev->num_pages);
373 static void virtio_balloon_save(QEMUFile *f, void *opaque)
375 virtio_save(VIRTIO_DEVICE(opaque), f);
378 static void virtio_balloon_save_device(VirtIODevice *vdev, QEMUFile *f)
380 VirtIOBalloon *s = VIRTIO_BALLOON(vdev);
382 qemu_put_be32(f, s->num_pages);
383 qemu_put_be32(f, s->actual);
386 static int virtio_balloon_load(QEMUFile *f, void *opaque, int version_id)
388 if (version_id != 1)
389 return -EINVAL;
391 return virtio_load(VIRTIO_DEVICE(opaque), f, version_id);
394 static int virtio_balloon_load_device(VirtIODevice *vdev, QEMUFile *f,
395 int version_id)
397 VirtIOBalloon *s = VIRTIO_BALLOON(vdev);
399 s->num_pages = qemu_get_be32(f);
400 s->actual = qemu_get_be32(f);
401 return 0;
404 static void virtio_balloon_device_realize(DeviceState *dev, Error **errp)
406 VirtIODevice *vdev = VIRTIO_DEVICE(dev);
407 VirtIOBalloon *s = VIRTIO_BALLOON(dev);
408 int ret;
410 virtio_init(vdev, "virtio-balloon", VIRTIO_ID_BALLOON,
411 sizeof(struct virtio_balloon_config));
413 ret = qemu_add_balloon_handler(virtio_balloon_to_target,
414 virtio_balloon_stat, s);
416 if (ret < 0) {
417 error_setg(errp, "Only one balloon device is supported");
418 virtio_cleanup(vdev);
419 return;
422 s->ivq = virtio_add_queue(vdev, 128, virtio_balloon_handle_output);
423 s->dvq = virtio_add_queue(vdev, 128, virtio_balloon_handle_output);
424 s->svq = virtio_add_queue(vdev, 128, virtio_balloon_receive_stats);
426 reset_stats(s);
428 register_savevm(dev, "virtio-balloon", -1, 1,
429 virtio_balloon_save, virtio_balloon_load, s);
432 static void virtio_balloon_device_unrealize(DeviceState *dev, Error **errp)
434 VirtIODevice *vdev = VIRTIO_DEVICE(dev);
435 VirtIOBalloon *s = VIRTIO_BALLOON(dev);
437 balloon_stats_destroy_timer(s);
438 qemu_remove_balloon_handler(s);
439 unregister_savevm(dev, "virtio-balloon", s);
440 virtio_cleanup(vdev);
443 static void virtio_balloon_instance_init(Object *obj)
445 VirtIOBalloon *s = VIRTIO_BALLOON(obj);
447 object_property_add(obj, "guest-stats", "guest statistics",
448 balloon_stats_get_all, NULL, NULL, s, NULL);
450 object_property_add(obj, "guest-stats-polling-interval", "int",
451 balloon_stats_get_poll_interval,
452 balloon_stats_set_poll_interval,
453 NULL, s, NULL);
456 static Property virtio_balloon_properties[] = {
457 DEFINE_PROP_BIT("deflate-on-oom", VirtIOBalloon, host_features,
458 VIRTIO_BALLOON_F_DEFLATE_ON_OOM, false),
459 DEFINE_PROP_END_OF_LIST(),
462 static void virtio_balloon_class_init(ObjectClass *klass, void *data)
464 DeviceClass *dc = DEVICE_CLASS(klass);
465 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
467 dc->props = virtio_balloon_properties;
468 set_bit(DEVICE_CATEGORY_MISC, dc->categories);
469 vdc->realize = virtio_balloon_device_realize;
470 vdc->unrealize = virtio_balloon_device_unrealize;
471 vdc->get_config = virtio_balloon_get_config;
472 vdc->set_config = virtio_balloon_set_config;
473 vdc->get_features = virtio_balloon_get_features;
474 vdc->save = virtio_balloon_save_device;
475 vdc->load = virtio_balloon_load_device;
478 static const TypeInfo virtio_balloon_info = {
479 .name = TYPE_VIRTIO_BALLOON,
480 .parent = TYPE_VIRTIO_DEVICE,
481 .instance_size = sizeof(VirtIOBalloon),
482 .instance_init = virtio_balloon_instance_init,
483 .class_init = virtio_balloon_class_init,
486 static void virtio_register_types(void)
488 type_register_static(&virtio_balloon_info);
491 type_init(virtio_register_types)