blob: 884570a57d1f6dcc81eacd5971c449431d49dc7c [file] [log] [blame]
/*
* Virtio Balloon Device
*
* Copyright IBM, Corp. 2008
* Copyright (C) 2011 Red Hat, Inc.
* Copyright (C) 2011 Amit Shah <amit.shah@redhat.com>
*
* Authors:
* Anthony Liguori <aliguori@us.ibm.com>
*
* This work is licensed under the terms of the GNU GPL, version 2. See
* the COPYING file in the top-level directory.
*
*/
#include "qemu/osdep.h"
#include "qemu/iov.h"
#include "qemu/timer.h"
#include "qemu-common.h"
#include "hw/virtio/virtio.h"
#include "hw/i386/pc.h"
#include "sysemu/balloon.h"
#include "hw/virtio/virtio-balloon.h"
#include "sysemu/kvm.h"
#include "exec/address-spaces.h"
#include "qapi/visitor.h"
#include "qapi-event.h"
#include "trace.h"
#include "hw/virtio/virtio-bus.h"
#include "hw/virtio/virtio-access.h"
#define BALLOON_PAGE_SIZE (1 << VIRTIO_BALLOON_PFN_SHIFT)
static void balloon_page(void *addr, int deflate)
{
if (!qemu_balloon_is_inhibited() && (!kvm_enabled() ||
kvm_has_sync_mmu())) {
qemu_madvise(addr, BALLOON_PAGE_SIZE,
deflate ? QEMU_MADV_WILLNEED : QEMU_MADV_DONTNEED);
}
}
static const char *balloon_stat_names[] = {
[VIRTIO_BALLOON_S_SWAP_IN] = "stat-swap-in",
[VIRTIO_BALLOON_S_SWAP_OUT] = "stat-swap-out",
[VIRTIO_BALLOON_S_MAJFLT] = "stat-major-faults",
[VIRTIO_BALLOON_S_MINFLT] = "stat-minor-faults",
[VIRTIO_BALLOON_S_MEMFREE] = "stat-free-memory",
[VIRTIO_BALLOON_S_MEMTOT] = "stat-total-memory",
[VIRTIO_BALLOON_S_AVAIL] = "stat-available-memory",
[VIRTIO_BALLOON_S_NR] = NULL
};
/*
* reset_stats - Mark all items in the stats array as unset
*
* This function needs to be called at device initialization and before
* updating to a set of newly-generated stats. This will ensure that no
* stale values stick around in case the guest reports a subset of the supported
* statistics.
*/
static inline void reset_stats(VirtIOBalloon *dev)
{
int i;
for (i = 0; i < VIRTIO_BALLOON_S_NR; dev->stats[i++] = -1);
}
static bool balloon_stats_supported(const VirtIOBalloon *s)
{
VirtIODevice *vdev = VIRTIO_DEVICE(s);
return virtio_vdev_has_feature(vdev, VIRTIO_BALLOON_F_STATS_VQ);
}
static bool balloon_stats_enabled(const VirtIOBalloon *s)
{
return s->stats_poll_interval > 0;
}
static void balloon_stats_destroy_timer(VirtIOBalloon *s)
{
if (balloon_stats_enabled(s)) {
timer_del(s->stats_timer);
timer_free(s->stats_timer);
s->stats_timer = NULL;
s->stats_poll_interval = 0;
}
}
static void balloon_stats_change_timer(VirtIOBalloon *s, int64_t secs)
{
timer_mod(s->stats_timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + secs * 1000);
}
static void balloon_stats_poll_cb(void *opaque)
{
VirtIOBalloon *s = opaque;
VirtIODevice *vdev = VIRTIO_DEVICE(s);
if (s->stats_vq_elem == NULL || !balloon_stats_supported(s)) {
/* re-schedule */
balloon_stats_change_timer(s, s->stats_poll_interval);
return;
}
virtqueue_push(s->svq, s->stats_vq_elem, s->stats_vq_offset);
virtio_notify(vdev, s->svq);
g_free(s->stats_vq_elem);
s->stats_vq_elem = NULL;
}
static void balloon_stats_get_all(Object *obj, Visitor *v, const char *name,
void *opaque, Error **errp)
{
Error *err = NULL;
VirtIOBalloon *s = opaque;
int i;
visit_start_struct(v, name, NULL, 0, &err);
if (err) {
goto out;
}
visit_type_int(v, "last-update", &s->stats_last_update, &err);
if (err) {
goto out_end;
}
visit_start_struct(v, "stats", NULL, 0, &err);
if (err) {
goto out_end;
}
for (i = 0; i < VIRTIO_BALLOON_S_NR; i++) {
visit_type_uint64(v, balloon_stat_names[i], &s->stats[i], &err);
if (err) {
goto out_nested;
}
}
visit_check_struct(v, &err);
out_nested:
visit_end_struct(v, NULL);
if (!err) {
visit_check_struct(v, &err);
}
out_end:
visit_end_struct(v, NULL);
out:
error_propagate(errp, err);
}
static void balloon_stats_get_poll_interval(Object *obj, Visitor *v,
const char *name, void *opaque,
Error **errp)
{
VirtIOBalloon *s = opaque;
visit_type_int(v, name, &s->stats_poll_interval, errp);
}
static void balloon_stats_set_poll_interval(Object *obj, Visitor *v,
const char *name, void *opaque,
Error **errp)
{
VirtIOBalloon *s = opaque;
Error *local_err = NULL;
int64_t value;
visit_type_int(v, name, &value, &local_err);
if (local_err) {
error_propagate(errp, local_err);
return;
}
if (value < 0) {
error_setg(errp, "timer value must be greater than zero");
return;
}
if (value > UINT32_MAX) {
error_setg(errp, "timer value is too big");
return;
}
if (value == s->stats_poll_interval) {
return;
}
if (value == 0) {
/* timer=0 disables the timer */
balloon_stats_destroy_timer(s);
return;
}
if (balloon_stats_enabled(s)) {
/* timer interval change */
s->stats_poll_interval = value;
balloon_stats_change_timer(s, value);
return;
}
/* create a new timer */
g_assert(s->stats_timer == NULL);
s->stats_timer = timer_new_ms(QEMU_CLOCK_VIRTUAL, balloon_stats_poll_cb, s);
s->stats_poll_interval = value;
balloon_stats_change_timer(s, 0);
}
static void virtio_balloon_handle_output(VirtIODevice *vdev, VirtQueue *vq)
{
VirtIOBalloon *s = VIRTIO_BALLOON(vdev);
VirtQueueElement *elem;
MemoryRegionSection section;
for (;;) {
size_t offset = 0;
uint32_t pfn;
elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
if (!elem) {
return;
}
while (iov_to_buf(elem->out_sg, elem->out_num, offset, &pfn, 4) == 4) {
ram_addr_t pa;
ram_addr_t addr;
int p = virtio_ldl_p(vdev, &pfn);
pa = (ram_addr_t) p << VIRTIO_BALLOON_PFN_SHIFT;
offset += 4;
/* FIXME: remove get_system_memory(), but how? */
section = memory_region_find(get_system_memory(), pa, 1);
if (!int128_nz(section.size) || !memory_region_is_ram(section.mr))
continue;
trace_virtio_balloon_handle_output(memory_region_name(section.mr),
pa);
/* Using memory_region_get_ram_ptr is bending the rules a bit, but
should be OK because we only want a single page. */
addr = section.offset_within_region;
balloon_page(memory_region_get_ram_ptr(section.mr) + addr,
!!(vq == s->dvq));
memory_region_unref(section.mr);
}
virtqueue_push(vq, elem, offset);
virtio_notify(vdev, vq);
g_free(elem);
}
}
static void virtio_balloon_receive_stats(VirtIODevice *vdev, VirtQueue *vq)
{
VirtIOBalloon *s = VIRTIO_BALLOON(vdev);
VirtQueueElement *elem;
VirtIOBalloonStat stat;
size_t offset = 0;
qemu_timeval tv;
elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
if (!elem) {
goto out;
}
if (s->stats_vq_elem != NULL) {
/* This should never happen if the driver follows the spec. */
virtqueue_push(vq, s->stats_vq_elem, 0);
virtio_notify(vdev, vq);
g_free(s->stats_vq_elem);
}
s->stats_vq_elem = elem;
/* Initialize the stats to get rid of any stale values. This is only
* needed to handle the case where a guest supports fewer stats than it
* used to (ie. it has booted into an old kernel).
*/
reset_stats(s);
while (iov_to_buf(elem->out_sg, elem->out_num, offset, &stat, sizeof(stat))
== sizeof(stat)) {
uint16_t tag = virtio_tswap16(vdev, stat.tag);
uint64_t val = virtio_tswap64(vdev, stat.val);
offset += sizeof(stat);
if (tag < VIRTIO_BALLOON_S_NR)
s->stats[tag] = val;
}
s->stats_vq_offset = offset;
if (qemu_gettimeofday(&tv) < 0) {
fprintf(stderr, "warning: %s: failed to get time of day\n", __func__);
goto out;
}
s->stats_last_update = tv.tv_sec;
out:
if (balloon_stats_enabled(s)) {
balloon_stats_change_timer(s, s->stats_poll_interval);
}
}
static void virtio_balloon_get_config(VirtIODevice *vdev, uint8_t *config_data)
{
VirtIOBalloon *dev = VIRTIO_BALLOON(vdev);
struct virtio_balloon_config config;
config.num_pages = cpu_to_le32(dev->num_pages);
config.actual = cpu_to_le32(dev->actual);
trace_virtio_balloon_get_config(config.num_pages, config.actual);
memcpy(config_data, &config, sizeof(struct virtio_balloon_config));
}
static int build_dimm_list(Object *obj, void *opaque)
{
GSList **list = opaque;
if (object_dynamic_cast(obj, TYPE_PC_DIMM)) {
DeviceState *dev = DEVICE(obj);
if (dev->realized) { /* only realized DIMMs matter */
*list = g_slist_prepend(*list, dev);
}
}
object_child_foreach(obj, build_dimm_list, opaque);
return 0;
}
static ram_addr_t get_current_ram_size(void)
{
GSList *list = NULL, *item;
ram_addr_t size = ram_size;
build_dimm_list(qdev_get_machine(), &list);
for (item = list; item; item = g_slist_next(item)) {
Object *obj = OBJECT(item->data);
if (!strcmp(object_get_typename(obj), TYPE_PC_DIMM)) {
size += object_property_get_int(obj, PC_DIMM_SIZE_PROP,
&error_abort);
}
}
g_slist_free(list);
return size;
}
static void virtio_balloon_set_config(VirtIODevice *vdev,
const uint8_t *config_data)
{
VirtIOBalloon *dev = VIRTIO_BALLOON(vdev);
struct virtio_balloon_config config;
uint32_t oldactual = dev->actual;
ram_addr_t vm_ram_size = get_current_ram_size();
memcpy(&config, config_data, sizeof(struct virtio_balloon_config));
dev->actual = le32_to_cpu(config.actual);
if (dev->actual != oldactual) {
qapi_event_send_balloon_change(vm_ram_size -
((ram_addr_t) dev->actual << VIRTIO_BALLOON_PFN_SHIFT),
&error_abort);
}
trace_virtio_balloon_set_config(dev->actual, oldactual);
}
static uint64_t virtio_balloon_get_features(VirtIODevice *vdev, uint64_t f,
Error **errp)
{
VirtIOBalloon *dev = VIRTIO_BALLOON(vdev);
f |= dev->host_features;
virtio_add_feature(&f, VIRTIO_BALLOON_F_STATS_VQ);
return f;
}
static void virtio_balloon_stat(void *opaque, BalloonInfo *info)
{
VirtIOBalloon *dev = opaque;
info->actual = get_current_ram_size() - ((uint64_t) dev->actual <<
VIRTIO_BALLOON_PFN_SHIFT);
}
static void virtio_balloon_to_target(void *opaque, ram_addr_t target)
{
VirtIOBalloon *dev = VIRTIO_BALLOON(opaque);
VirtIODevice *vdev = VIRTIO_DEVICE(dev);
ram_addr_t vm_ram_size = get_current_ram_size();
if (target > vm_ram_size) {
target = vm_ram_size;
}
if (target) {
dev->num_pages = (vm_ram_size - target) >> VIRTIO_BALLOON_PFN_SHIFT;
virtio_notify_config(vdev);
}
trace_virtio_balloon_to_target(target, dev->num_pages);
}
static int virtio_balloon_post_load_device(void *opaque, int version_id)
{
VirtIOBalloon *s = VIRTIO_BALLOON(opaque);
if (balloon_stats_enabled(s)) {
balloon_stats_change_timer(s, s->stats_poll_interval);
}
return 0;
}
static const VMStateDescription vmstate_virtio_balloon_device = {
.name = "virtio-balloon-device",
.version_id = 1,
.minimum_version_id = 1,
.post_load = virtio_balloon_post_load_device,
.fields = (VMStateField[]) {
VMSTATE_UINT32(num_pages, VirtIOBalloon),
VMSTATE_UINT32(actual, VirtIOBalloon),
VMSTATE_END_OF_LIST()
},
};
static void virtio_balloon_device_realize(DeviceState *dev, Error **errp)
{
VirtIODevice *vdev = VIRTIO_DEVICE(dev);
VirtIOBalloon *s = VIRTIO_BALLOON(dev);
int ret;
virtio_init(vdev, "virtio-balloon", VIRTIO_ID_BALLOON,
sizeof(struct virtio_balloon_config));
ret = qemu_add_balloon_handler(virtio_balloon_to_target,
virtio_balloon_stat, s);
if (ret < 0) {
error_setg(errp, "Only one balloon device is supported");
virtio_cleanup(vdev);
return;
}
s->ivq = virtio_add_queue(vdev, 128, virtio_balloon_handle_output);
s->dvq = virtio_add_queue(vdev, 128, virtio_balloon_handle_output);
s->svq = virtio_add_queue(vdev, 128, virtio_balloon_receive_stats);
reset_stats(s);
}
static void virtio_balloon_device_unrealize(DeviceState *dev, Error **errp)
{
VirtIODevice *vdev = VIRTIO_DEVICE(dev);
VirtIOBalloon *s = VIRTIO_BALLOON(dev);
balloon_stats_destroy_timer(s);
qemu_remove_balloon_handler(s);
virtio_cleanup(vdev);
}
static void virtio_balloon_device_reset(VirtIODevice *vdev)
{
VirtIOBalloon *s = VIRTIO_BALLOON(vdev);
if (s->stats_vq_elem != NULL) {
virtqueue_unpop(s->svq, s->stats_vq_elem, 0);
g_free(s->stats_vq_elem);
s->stats_vq_elem = NULL;
}
}
static void virtio_balloon_set_status(VirtIODevice *vdev, uint8_t status)
{
VirtIOBalloon *s = VIRTIO_BALLOON(vdev);
if (!s->stats_vq_elem && vdev->vm_running &&
(status & VIRTIO_CONFIG_S_DRIVER_OK) && virtqueue_rewind(s->svq, 1)) {
/* poll stats queue for the element we have discarded when the VM
* was stopped */
virtio_balloon_receive_stats(vdev, s->svq);
}
}
static void virtio_balloon_instance_init(Object *obj)
{
VirtIOBalloon *s = VIRTIO_BALLOON(obj);
object_property_add(obj, "guest-stats", "guest statistics",
balloon_stats_get_all, NULL, NULL, s, NULL);
object_property_add(obj, "guest-stats-polling-interval", "int",
balloon_stats_get_poll_interval,
balloon_stats_set_poll_interval,
NULL, s, NULL);
}
static const VMStateDescription vmstate_virtio_balloon = {
.name = "virtio-balloon",
.minimum_version_id = 1,
.version_id = 1,
.fields = (VMStateField[]) {
VMSTATE_VIRTIO_DEVICE,
VMSTATE_END_OF_LIST()
},
};
static Property virtio_balloon_properties[] = {
DEFINE_PROP_BIT("deflate-on-oom", VirtIOBalloon, host_features,
VIRTIO_BALLOON_F_DEFLATE_ON_OOM, false),
DEFINE_PROP_END_OF_LIST(),
};
static void virtio_balloon_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
dc->props = virtio_balloon_properties;
dc->vmsd = &vmstate_virtio_balloon;
set_bit(DEVICE_CATEGORY_MISC, dc->categories);
vdc->realize = virtio_balloon_device_realize;
vdc->unrealize = virtio_balloon_device_unrealize;
vdc->reset = virtio_balloon_device_reset;
vdc->get_config = virtio_balloon_get_config;
vdc->set_config = virtio_balloon_set_config;
vdc->get_features = virtio_balloon_get_features;
vdc->set_status = virtio_balloon_set_status;
vdc->vmsd = &vmstate_virtio_balloon_device;
}
static const TypeInfo virtio_balloon_info = {
.name = TYPE_VIRTIO_BALLOON,
.parent = TYPE_VIRTIO_DEVICE,
.instance_size = sizeof(VirtIOBalloon),
.instance_init = virtio_balloon_instance_init,
.class_init = virtio_balloon_class_init,
};
static void virtio_register_types(void)
{
type_register_static(&virtio_balloon_info);
}
type_init(virtio_register_types)