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qemu / qemu / 31ae8bb15d4ddaa202ffeb03a5c90f0acf205472 / . / hw / hyperv / hv-balloon.c
blob: ade283335a68ad9e832d0d3c7bdfd501e560d8ea [file] [log] [blame]
/*
* QEMU Hyper-V Dynamic Memory Protocol driver
*
* Copyright (C) 2020-2023 Oracle and/or its affiliates.
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*/
#include "qemu/osdep.h"
#include "hv-balloon-internal.h"
#include "exec/address-spaces.h"
#include "exec/cpu-common.h"
#include "exec/ramblock.h"
#include "hw/boards.h"
#include "hw/hyperv/dynmem-proto.h"
#include "hw/hyperv/hv-balloon.h"
#include "hw/hyperv/vmbus.h"
#include "hw/mem/memory-device.h"
#include "hw/mem/pc-dimm.h"
#include "hw/qdev-core.h"
#include "hw/qdev-properties.h"
#include "monitor/qdev.h"
#include "qapi/error.h"
#include "qapi/qapi-commands-machine.h"
#include "qapi/qapi-events-machine.h"
#include "qapi/qapi-types-machine.h"
#include "qapi/qmp/qdict.h"
#include "qapi/visitor.h"
#include "qemu/error-report.h"
#include "qemu/module.h"
#include "qemu/units.h"
#include "qemu/timer.h"
#include "sysemu/balloon.h"
#include "sysemu/hostmem.h"
#include "sysemu/reset.h"
#include "hv-balloon-our_range_memslots.h"
#include "hv-balloon-page_range_tree.h"
#include "trace.h"
#define HV_BALLOON_ADDR_PROP "addr"
#define HV_BALLOON_MEMDEV_PROP "memdev"
#define HV_BALLOON_GUID "525074DC-8985-46e2-8057-A307DC18A502"
/*
* Some Windows versions (at least Server 2019) will crash with various
* error codes when receiving DM protocol requests (at least
* DM_MEM_HOT_ADD_REQUEST) immediately after boot.
*
* It looks like Hyper-V from Server 2016 uses a 50-second after-boot
* delay, probably to workaround this issue, so we'll use this value, too.
*/
#define HV_BALLOON_POST_INIT_WAIT (50 * 1000)
#define HV_BALLOON_HA_CHUNK_SIZE (2 * GiB)
#define HV_BALLOON_HA_CHUNK_PAGES (HV_BALLOON_HA_CHUNK_SIZE / HV_BALLOON_PAGE_SIZE)
#define HV_BALLOON_HA_MEMSLOT_SIZE_ALIGN (128 * MiB)
#define HV_BALLOON_HR_CHUNK_PAGES 585728
/*
* ^ that's the maximum number of pages
* that Windows returns in one hot remove response
*
* If the number requested is too high Windows will no longer honor
* these requests
*/
struct HvBalloonClass {
VMBusDeviceClass parent_class;
} HvBalloonClass;
typedef enum State {
/* not a real state */
S_NO_CHANGE = 0,
S_WAIT_RESET,
S_POST_RESET_CLOSED,
/* init flow */
S_VERSION,
S_CAPS,
S_POST_INIT_WAIT,
S_IDLE,
/* balloon op flow */
S_BALLOON_POSTING,
S_BALLOON_RB_WAIT,
S_BALLOON_REPLY_WAIT,
/* unballoon + hot add ops flow */
S_UNBALLOON_POSTING,
S_UNBALLOON_RB_WAIT,
S_UNBALLOON_REPLY_WAIT,
S_HOT_ADD_SETUP,
S_HOT_ADD_RB_WAIT,
S_HOT_ADD_POSTING,
S_HOT_ADD_REPLY_WAIT,
} State;
typedef struct StateDesc {
State state;
const char *desc;
} StateDesc;
typedef struct HvBalloon {
VMBusDevice parent;
State state;
union dm_version version;
union dm_caps caps;
QEMUTimer post_init_timer;
unsigned int trans_id;
struct {
bool enabled;
bool received;
uint64_t committed;
uint64_t available;
} status_report;
/* Guest target size */
uint64_t target;
bool target_changed;
/* Current (un)balloon / hot-add operation parameters */
union {
uint64_t balloon_diff;
struct {
uint64_t unballoon_diff;
uint64_t hot_add_diff;
};
struct {
PageRange hot_add_range;
uint64_t ha_current_count;
};
};
OurRangeMemslots *our_range;
/* Count of memslots covering our memory */
unsigned int memslot_count;
/* Nominal size of each memslot (the last one might be smaller) */
uint64_t memslot_size;
/* Non-ours removed memory */
PageRangeTree removed_guest, removed_both;
/* Grand totals of removed memory (both ours and non-ours) */
uint64_t removed_guest_ctr, removed_both_ctr;
/* MEMORY_DEVICE props */
uint64_t addr;
HostMemoryBackend *hostmem;
MemoryRegion *mr;
} HvBalloon;
OBJECT_DEFINE_TYPE_WITH_INTERFACES(HvBalloon, hv_balloon, HV_BALLOON, VMBUS_DEVICE, \
{ TYPE_MEMORY_DEVICE }, { })
#define HV_BALLOON_SET_STATE(hvb, news) \
do { \
assert(news != S_NO_CHANGE); \
hv_balloon_state_set(hvb, news, # news); \
} while (0)
#define HV_BALLOON_STATE_DESC_SET(stdesc, news) \
_hv_balloon_state_desc_set(stdesc, news, # news)
#define HV_BALLOON_STATE_DESC_INIT \
{ \
.state = S_NO_CHANGE, \
}
typedef struct HvBalloonReq {
VMBusChanReq vmreq;
} HvBalloonReq;
/* total our memory includes parts currently removed from the guest */
static uint64_t hv_balloon_total_our_ram(HvBalloon *balloon)
{
if (!balloon->our_range) {
return 0;
}
return balloon->our_range->range.added;
}
/* TODO: unify the code below with virtio-balloon and cache the value */
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 = current_machine->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;
}
/* total RAM includes memory currently removed from the guest */
static uint64_t hv_balloon_total_ram(HvBalloon *balloon)
{
ram_addr_t ram_size = get_current_ram_size();
uint64_t ram_size_pages = ram_size >> HV_BALLOON_PFN_SHIFT;
uint64_t our_ram_size_pages = hv_balloon_total_our_ram(balloon);
assert(ram_size_pages > 0);
return SUM_SATURATE_U64(ram_size_pages, our_ram_size_pages);
}
/*
* calculating the total RAM size is a slow operation,
* avoid it as much as possible
*/
static uint64_t hv_balloon_total_removed_rs(HvBalloon *balloon,
uint64_t ram_size_pages)
{
uint64_t total_removed;
total_removed = SUM_SATURATE_U64(balloon->removed_guest_ctr,
balloon->removed_both_ctr);
/* possible if guest returns pages outside actual RAM */
if (total_removed > ram_size_pages) {
total_removed = ram_size_pages;
}
return total_removed;
}
/* Returns whether the state has actually changed */
static bool hv_balloon_state_set(HvBalloon *balloon,
State newst, const char *newststr)
{
if (newst == S_NO_CHANGE || balloon->state == newst) {
return false;
}
balloon->state = newst;
trace_hv_balloon_state_change(newststr);
return true;
}
static void _hv_balloon_state_desc_set(StateDesc *stdesc,
State newst, const char *newststr)
{
/* state setting is only permitted on a freshly init desc */
assert(stdesc->state == S_NO_CHANGE);
assert(newst != S_NO_CHANGE);
stdesc->state = newst;
stdesc->desc = newststr;
}
static VMBusChannel *hv_balloon_get_channel_maybe(HvBalloon *balloon)
{
return vmbus_device_channel(&balloon->parent, 0);
}
static VMBusChannel *hv_balloon_get_channel(HvBalloon *balloon)
{
VMBusChannel *chan;
chan = hv_balloon_get_channel_maybe(balloon);
assert(chan != NULL);
return chan;
}
static ssize_t hv_balloon_send_packet(VMBusChannel *chan,
struct dm_message *msg)
{
int ret;
ret = vmbus_channel_reserve(chan, 0, msg->hdr.size);
if (ret < 0) {
return ret;
}
return vmbus_channel_send(chan, VMBUS_PACKET_DATA_INBAND,
NULL, 0, msg, msg->hdr.size, false,
msg->hdr.trans_id);
}
static bool hv_balloon_unballoon_get_source(HvBalloon *balloon,
PageRangeTree *dtree,
uint64_t **dctr,
bool *is_our_range)
{
OurRange *our_range = OUR_RANGE(balloon->our_range);
/* Try the boot memory first */
if (g_tree_nnodes(balloon->removed_guest.t) > 0) {
*dtree = balloon->removed_guest;
*dctr = &balloon->removed_guest_ctr;
*is_our_range = false;
} else if (g_tree_nnodes(balloon->removed_both.t) > 0) {
*dtree = balloon->removed_both;
*dctr = &balloon->removed_both_ctr;
*is_our_range = false;
} else if (!our_range) {
return false;
} else if (!our_range_is_removed_tree_empty(our_range, false)) {
*dtree = our_range_get_removed_tree(our_range, false);
*dctr = &balloon->removed_guest_ctr;
*is_our_range = true;
} else if (!our_range_is_removed_tree_empty(our_range, true)) {
*dtree = our_range_get_removed_tree(our_range, true);
*dctr = &balloon->removed_both_ctr;
*is_our_range = true;
} else {
return false;
}
return true;
}
static void hv_balloon_unballoon_rb_wait(HvBalloon *balloon, StateDesc *stdesc)
{
VMBusChannel *chan = hv_balloon_get_channel(balloon);
struct dm_unballoon_request *ur;
size_t ur_size = sizeof(*ur) + sizeof(ur->range_array[0]);
assert(balloon->state == S_UNBALLOON_RB_WAIT);
if (vmbus_channel_reserve(chan, 0, ur_size) < 0) {
return;
}
HV_BALLOON_STATE_DESC_SET(stdesc, S_UNBALLOON_POSTING);
}
static void hv_balloon_unballoon_posting(HvBalloon *balloon, StateDesc *stdesc)
{
VMBusChannel *chan = hv_balloon_get_channel(balloon);
PageRangeTree dtree;
uint64_t *dctr;
bool our_range;
struct dm_unballoon_request *ur;
size_t ur_size = sizeof(*ur) + sizeof(ur->range_array[0]);
PageRange range;
bool bret;
ssize_t ret;
assert(balloon->state == S_UNBALLOON_POSTING);
assert(balloon->unballoon_diff > 0);
if (!hv_balloon_unballoon_get_source(balloon, &dtree, &dctr, &our_range)) {
error_report("trying to unballoon but nothing seems to be ballooned");
/*
* there is little we can do as we might have already
* sent the guest a partial request we can't cancel
*/
return;
}
assert(balloon->our_range || !our_range);
assert(dtree.t);
assert(dctr);
ur = alloca(ur_size);
memset(ur, 0, ur_size);
ur->hdr.type = DM_UNBALLOON_REQUEST;
ur->hdr.size = ur_size;
ur->hdr.trans_id = balloon->trans_id;
bret = hvb_page_range_tree_pop(dtree, &range, MIN(balloon->unballoon_diff,
HV_BALLOON_HA_CHUNK_PAGES));
assert(bret);
/* TODO: madvise? */
*dctr -= range.count;
balloon->unballoon_diff -= range.count;
ur->range_count = 1;
ur->range_array[0].finfo.start_page = range.start;
ur->range_array[0].finfo.page_cnt = range.count;
ur->more_pages = balloon->unballoon_diff > 0;
trace_hv_balloon_outgoing_unballoon(ur->hdr.trans_id,
range.count, range.start,
balloon->unballoon_diff);
if (ur->more_pages) {
HV_BALLOON_STATE_DESC_SET(stdesc, S_UNBALLOON_RB_WAIT);
} else {
HV_BALLOON_STATE_DESC_SET(stdesc, S_UNBALLOON_REPLY_WAIT);
}
ret = vmbus_channel_send(chan, VMBUS_PACKET_DATA_INBAND,
NULL, 0, ur, ur_size, false,
ur->hdr.trans_id);
if (ret <= 0) {
error_report("error %zd when posting unballoon msg, expect problems",
ret);
}
}
static bool hv_balloon_our_range_ensure(HvBalloon *balloon)
{
uint64_t align;
MemoryRegion *hostmem_mr;
g_autoptr(OurRangeMemslots) our_range_memslots = NULL;
OurRange *our_range;
if (balloon->our_range) {
return true;
}
if (!balloon->hostmem) {
return false;
}
align = (1 << balloon->caps.cap_bits.hot_add_alignment) * MiB;
assert(QEMU_IS_ALIGNED(balloon->addr, align));
hostmem_mr = host_memory_backend_get_memory(balloon->hostmem);
our_range_memslots = hvb_our_range_memslots_new(balloon->addr,
balloon->mr, hostmem_mr,
OBJECT(balloon),
balloon->memslot_count,
balloon->memslot_size);
our_range = OUR_RANGE(our_range_memslots);
if (hvb_page_range_tree_intree_any(balloon->removed_guest,
our_range->range.start,
our_range->range.count) ||
hvb_page_range_tree_intree_any(balloon->removed_both,
our_range->range.start,
our_range->range.count)) {
error_report("some parts of the memory backend were already returned by the guest. this should not happen, please reboot the guest and try again");
return false;
}
trace_hv_balloon_our_range_add(our_range->range.count,
our_range->range.start);
balloon->our_range = g_steal_pointer(&our_range_memslots);
return true;
}
static void hv_balloon_hot_add_setup(HvBalloon *balloon, StateDesc *stdesc)
{
/* need to make copy since it is in union with hot_add_range */
uint64_t hot_add_diff = balloon->hot_add_diff;
PageRange *hot_add_range = &balloon->hot_add_range;
uint64_t align, our_range_remaining;
OurRange *our_range;
assert(balloon->state == S_HOT_ADD_SETUP);
assert(hot_add_diff > 0);
if (!hv_balloon_our_range_ensure(balloon)) {
goto ret_idle;
}
our_range = OUR_RANGE(balloon->our_range);
align = (1 << balloon->caps.cap_bits.hot_add_alignment) *
(MiB / HV_BALLOON_PAGE_SIZE);
/* Absolute GPA in pages */
hot_add_range->start = our_range_get_remaining_start(our_range);
assert(QEMU_IS_ALIGNED(hot_add_range->start, align));
our_range_remaining = our_range_get_remaining_size(our_range);
hot_add_range->count = MIN(our_range_remaining, hot_add_diff);
hot_add_range->count = QEMU_ALIGN_DOWN(hot_add_range->count, align);
if (hot_add_range->count == 0) {
goto ret_idle;
}
hvb_our_range_memslots_ensure_mapped_additional(balloon->our_range,
hot_add_range->count);
HV_BALLOON_STATE_DESC_SET(stdesc, S_HOT_ADD_RB_WAIT);
return;
ret_idle:
HV_BALLOON_STATE_DESC_SET(stdesc, S_IDLE);
}
static void hv_balloon_hot_add_rb_wait(HvBalloon *balloon, StateDesc *stdesc)
{
VMBusChannel *chan = hv_balloon_get_channel(balloon);
struct dm_hot_add *ha;
size_t ha_size = sizeof(*ha) + sizeof(ha->range);
assert(balloon->state == S_HOT_ADD_RB_WAIT);
if (vmbus_channel_reserve(chan, 0, ha_size) < 0) {
return;
}
HV_BALLOON_STATE_DESC_SET(stdesc, S_HOT_ADD_POSTING);
}
static void hv_balloon_hot_add_posting(HvBalloon *balloon, StateDesc *stdesc)
{
PageRange *hot_add_range = &balloon->hot_add_range;
uint64_t *current_count = &balloon->ha_current_count;
VMBusChannel *chan = hv_balloon_get_channel(balloon);
struct dm_hot_add *ha;
size_t ha_size = sizeof(*ha) + sizeof(ha->range);
union dm_mem_page_range *ha_region;
uint64_t align, chunk_max_size;
ssize_t ret;
assert(balloon->state == S_HOT_ADD_POSTING);
assert(hot_add_range->count > 0);
align = (1 << balloon->caps.cap_bits.hot_add_alignment) *
(MiB / HV_BALLOON_PAGE_SIZE);
if (align >= HV_BALLOON_HA_CHUNK_PAGES) {
/*
* If the required alignment is higher than the chunk size we let it
* override that size.
*/
chunk_max_size = align;
} else {
chunk_max_size = QEMU_ALIGN_DOWN(HV_BALLOON_HA_CHUNK_PAGES, align);
}
/*
* hot_add_range->count starts aligned in hv_balloon_hot_add_setup(),
* then it is either reduced by subtracting aligned current_count or
* further hot-adds are prevented by marking the whole remaining our range
* as unusable in hv_balloon_handle_hot_add_response().
*/
*current_count = MIN(hot_add_range->count, chunk_max_size);
ha = alloca(ha_size);
ha_region = &(&ha->range)[1];
memset(ha, 0, ha_size);
ha->hdr.type = DM_MEM_HOT_ADD_REQUEST;
ha->hdr.size = ha_size;
ha->hdr.trans_id = balloon->trans_id;
ha->range.finfo.start_page = hot_add_range->start;
ha->range.finfo.page_cnt = *current_count;
ha_region->finfo.start_page = hot_add_range->start;
ha_region->finfo.page_cnt = ha->range.finfo.page_cnt;
trace_hv_balloon_outgoing_hot_add(ha->hdr.trans_id,
*current_count, hot_add_range->start);
ret = vmbus_channel_send(chan, VMBUS_PACKET_DATA_INBAND,
NULL, 0, ha, ha_size, false,
ha->hdr.trans_id);
if (ret <= 0) {
error_report("error %zd when posting hot add msg, expect problems",
ret);
}
HV_BALLOON_STATE_DESC_SET(stdesc, S_HOT_ADD_REPLY_WAIT);
}
static void hv_balloon_balloon_rb_wait(HvBalloon *balloon, StateDesc *stdesc)
{
VMBusChannel *chan = hv_balloon_get_channel(balloon);
size_t bl_size = sizeof(struct dm_balloon);
assert(balloon->state == S_BALLOON_RB_WAIT);
if (vmbus_channel_reserve(chan, 0, bl_size) < 0) {
return;
}
HV_BALLOON_STATE_DESC_SET(stdesc, S_BALLOON_POSTING);
}
static void hv_balloon_balloon_posting(HvBalloon *balloon, StateDesc *stdesc)
{
VMBusChannel *chan = hv_balloon_get_channel(balloon);
struct dm_balloon bl;
size_t bl_size = sizeof(bl);
ssize_t ret;
assert(balloon->state == S_BALLOON_POSTING);
assert(balloon->balloon_diff > 0);
memset(&bl, 0, sizeof(bl));
bl.hdr.type = DM_BALLOON_REQUEST;
bl.hdr.size = bl_size;
bl.hdr.trans_id = balloon->trans_id;
bl.num_pages = MIN(balloon->balloon_diff, HV_BALLOON_HR_CHUNK_PAGES);
trace_hv_balloon_outgoing_balloon(bl.hdr.trans_id, bl.num_pages,
balloon->balloon_diff);
ret = vmbus_channel_send(chan, VMBUS_PACKET_DATA_INBAND,
NULL, 0, &bl, bl_size, false,
bl.hdr.trans_id);
if (ret <= 0) {
error_report("error %zd when posting balloon msg, expect problems",
ret);
}
HV_BALLOON_STATE_DESC_SET(stdesc, S_BALLOON_REPLY_WAIT);
}
static void hv_balloon_idle_state_process_target(HvBalloon *balloon,
StateDesc *stdesc)
{
bool can_balloon = balloon->caps.cap_bits.balloon;
uint64_t ram_size_pages, total_removed;
ram_size_pages = hv_balloon_total_ram(balloon);
total_removed = hv_balloon_total_removed_rs(balloon, ram_size_pages);
/*
* we need to cache the values computed from the balloon target value when
* starting the adjustment procedure in case someone changes the target when
* the procedure is in progress
*/
if (balloon->target > ram_size_pages - total_removed) {
bool can_hot_add = balloon->caps.cap_bits.hot_add;
uint64_t target_diff = balloon->target -
(ram_size_pages - total_removed);
balloon->unballoon_diff = MIN(target_diff, total_removed);
if (can_hot_add) {
balloon->hot_add_diff = target_diff - balloon->unballoon_diff;
} else {
balloon->hot_add_diff = 0;
}
if (balloon->unballoon_diff > 0) {
assert(can_balloon);
HV_BALLOON_STATE_DESC_SET(stdesc, S_UNBALLOON_RB_WAIT);
} else if (balloon->hot_add_diff > 0) {
HV_BALLOON_STATE_DESC_SET(stdesc, S_HOT_ADD_SETUP);
}
} else if (can_balloon &&
balloon->target < ram_size_pages - total_removed) {
balloon->balloon_diff = ram_size_pages - total_removed -
balloon->target;
HV_BALLOON_STATE_DESC_SET(stdesc, S_BALLOON_RB_WAIT);
}
}
static void hv_balloon_idle_state(HvBalloon *balloon,
StateDesc *stdesc)
{
assert(balloon->state == S_IDLE);
if (balloon->target_changed) {
balloon->target_changed = false;
hv_balloon_idle_state_process_target(balloon, stdesc);
return;
}
}
static const struct {
void (*handler)(HvBalloon *balloon, StateDesc *stdesc);
} state_handlers[] = {
[S_IDLE].handler = hv_balloon_idle_state,
[S_BALLOON_POSTING].handler = hv_balloon_balloon_posting,
[S_BALLOON_RB_WAIT].handler = hv_balloon_balloon_rb_wait,
[S_UNBALLOON_POSTING].handler = hv_balloon_unballoon_posting,
[S_UNBALLOON_RB_WAIT].handler = hv_balloon_unballoon_rb_wait,
[S_HOT_ADD_SETUP].handler = hv_balloon_hot_add_setup,
[S_HOT_ADD_RB_WAIT].handler = hv_balloon_hot_add_rb_wait,
[S_HOT_ADD_POSTING].handler = hv_balloon_hot_add_posting,
};
static void hv_balloon_handle_state(HvBalloon *balloon, StateDesc *stdesc)
{
if (balloon->state >= ARRAY_SIZE(state_handlers) ||
!state_handlers[balloon->state].handler) {
return;
}
state_handlers[balloon->state].handler(balloon, stdesc);
}
static void hv_balloon_remove_response_insert_range(PageRangeTree tree,
const PageRange *range,
uint64_t *ctr1,
uint64_t *ctr2,
uint64_t *ctr3)
{
uint64_t dupcount, effcount;
if (range->count == 0) {
return;
}
dupcount = 0;
hvb_page_range_tree_insert(tree, range->start, range->count, &dupcount);
assert(dupcount <= range->count);
effcount = range->count - dupcount;
*ctr1 += effcount;
*ctr2 += effcount;
if (ctr3) {
*ctr3 += effcount;
}
}
static void hv_balloon_remove_response_handle_range(HvBalloon *balloon,
PageRange *range,
bool both,
uint64_t *removedctr)
{
OurRange *our_range = OUR_RANGE(balloon->our_range);
PageRangeTree globaltree =
both ? balloon->removed_both : balloon->removed_guest;
uint64_t *globalctr =
both ? &balloon->removed_both_ctr : &balloon->removed_guest_ctr;
PageRange rangeeff;
if (range->count == 0) {
return;
}
trace_hv_balloon_remove_response(range->count, range->start, both);
if (our_range) {
/* Includes the not-yet-hot-added and unusable parts. */
rangeeff = our_range->range;
} else {
rangeeff.start = rangeeff.count = 0;
}
if (page_range_intersection_size(range, rangeeff.start, rangeeff.count) > 0) {
PageRangeTree ourtree = our_range_get_removed_tree(our_range, both);
PageRange rangehole, rangecommon;
uint64_t ourremoved = 0;
/* process the hole before our range, if it exists */
page_range_part_before(range, rangeeff.start, &rangehole);
hv_balloon_remove_response_insert_range(globaltree, &rangehole,
globalctr, removedctr, NULL);
if (rangehole.count > 0) {
trace_hv_balloon_remove_response_hole(rangehole.count,
rangehole.start,
range->count, range->start,
rangeeff.start, both);
}
/* process our part */
page_range_intersect(range, rangeeff.start, rangeeff.count,
&rangecommon);
hv_balloon_remove_response_insert_range(ourtree, &rangecommon,
globalctr, removedctr,
&ourremoved);
if (rangecommon.count > 0) {
trace_hv_balloon_remove_response_common(rangecommon.count,
rangecommon.start,
range->count, range->start,
rangeeff.count,
rangeeff.start, ourremoved,
both);
}
/* calculate what's left after our range */
rangecommon = *range;
page_range_part_after(&rangecommon, rangeeff.start, rangeeff.count,
range);
}
/* process the remainder of the range that lies after our range */
if (range->count > 0) {
hv_balloon_remove_response_insert_range(globaltree, range,
globalctr, removedctr, NULL);
trace_hv_balloon_remove_response_remainder(range->count, range->start,
both);
range->count = 0;
}
}
static void hv_balloon_remove_response_handle_pages(HvBalloon *balloon,
PageRange *range,
uint64_t start,
uint64_t count,
bool both,
uint64_t *removedctr)
{
assert(count > 0);
/*
* if there is an existing range that the new range can't be joined to
* dump it into tree(s)
*/
if (range->count > 0 && !page_range_joinable(range, start, count)) {
hv_balloon_remove_response_handle_range(balloon, range, both,
removedctr);
}
if (range->count == 0) {
range->start = start;
range->count = count;
} else if (page_range_joinable_left(range, start, count)) {
range->start = start;
range->count += count;
} else { /* page_range_joinable_right() */
range->count += count;
}
}
static gboolean hv_balloon_handle_remove_host_addr_node(gpointer key,
gpointer value,
gpointer data)
{
PageRange *range = value;
uint64_t pageoff;
for (pageoff = 0; pageoff < range->count; ) {
uint64_t addr_64 = (range->start + pageoff) * HV_BALLOON_PAGE_SIZE;
void *addr;
RAMBlock *rb;
ram_addr_t rb_offset;
size_t rb_page_size;
size_t discard_size;
assert(addr_64 <= UINTPTR_MAX);
addr = (void *)((uintptr_t)addr_64);
rb = qemu_ram_block_from_host(addr, false, &rb_offset);
rb_page_size = qemu_ram_pagesize(rb);
if (rb_page_size != HV_BALLOON_PAGE_SIZE) {
/* TODO: these should end in "removed_guest" */
warn_report("guest reported removed page backed by unsupported page size %zu",
rb_page_size);
pageoff++;
continue;
}
discard_size = MIN(range->count - pageoff,
(rb->max_length - rb_offset) /
HV_BALLOON_PAGE_SIZE);
discard_size = MAX(discard_size, 1);
if (ram_block_discard_range(rb, rb_offset, discard_size *
HV_BALLOON_PAGE_SIZE) != 0) {
warn_report("guest reported removed page failed discard");
}
pageoff += discard_size;
}
return false;
}
static void hv_balloon_handle_remove_host_addr_tree(PageRangeTree tree)
{
g_tree_foreach(tree.t, hv_balloon_handle_remove_host_addr_node, NULL);
}
static int hv_balloon_handle_remove_section(PageRangeTree tree,
const MemoryRegionSection *section,
uint64_t count)
{
void *addr = memory_region_get_ram_ptr(section->mr) +
section->offset_within_region;
uint64_t addr_page;
assert(count > 0);
if ((uintptr_t)addr % HV_BALLOON_PAGE_SIZE) {
warn_report("guest reported removed pages at an unaligned host addr %p",
addr);
return -EINVAL;
}
addr_page = (uintptr_t)addr / HV_BALLOON_PAGE_SIZE;
hvb_page_range_tree_insert(tree, addr_page, count, NULL);
return 0;
}
static void hv_balloon_handle_remove_ranges(HvBalloon *balloon,
union dm_mem_page_range ranges[],
uint32_t count)
{
uint64_t removedcnt;
PageRangeTree removed_host_addr;
PageRange range_guest, range_both;
hvb_page_range_tree_init(&removed_host_addr);
range_guest.count = range_both.count = removedcnt = 0;
for (unsigned int ctr = 0; ctr < count; ctr++) {
union dm_mem_page_range *mr = &ranges[ctr];
hwaddr pa;
MemoryRegionSection section;
for (unsigned int offset = 0; offset < mr->finfo.page_cnt; ) {
int ret;
uint64_t pageno = mr->finfo.start_page + offset;
uint64_t pagecnt = 1;
pa = (hwaddr)pageno << HV_BALLOON_PFN_SHIFT;
section = memory_region_find(get_system_memory(), pa,
(mr->finfo.page_cnt - offset) *
HV_BALLOON_PAGE_SIZE);
if (!section.mr) {
warn_report("guest reported removed page %"PRIu64" not found in RAM",
pageno);
ret = -EINVAL;
goto finish_page;
}
pagecnt = int128_get64(section.size) / HV_BALLOON_PAGE_SIZE;
if (pagecnt <= 0) {
warn_report("guest reported removed page %"PRIu64" in a section smaller than page size",
pageno);
pagecnt = 1; /* skip the whole page */
ret = -EINVAL;
goto finish_page;
}
if (!memory_region_is_ram(section.mr) ||
memory_region_is_rom(section.mr) ||
memory_region_is_romd(section.mr)) {
warn_report("guest reported removed page %"PRIu64" in a section that is not an ordinary RAM",
pageno);
ret = -EINVAL;
goto finish_page;
}
ret = hv_balloon_handle_remove_section(removed_host_addr, &section,
pagecnt);
finish_page:
if (ret == 0) {
hv_balloon_remove_response_handle_pages(balloon,
&range_both,
pageno, pagecnt,
true, &removedcnt);
} else {
hv_balloon_remove_response_handle_pages(balloon,
&range_guest,
pageno, pagecnt,
false, &removedcnt);
}
if (section.mr) {
memory_region_unref(section.mr);
}
offset += pagecnt;
}
}
hv_balloon_remove_response_handle_range(balloon, &range_both, true,
&removedcnt);
hv_balloon_remove_response_handle_range(balloon, &range_guest, false,
&removedcnt);
hv_balloon_handle_remove_host_addr_tree(removed_host_addr);
hvb_page_range_tree_destroy(&removed_host_addr);
if (removedcnt > balloon->balloon_diff) {
warn_report("guest reported more pages removed than currently pending (%"PRIu64" vs %"PRIu64")",
removedcnt, balloon->balloon_diff);
balloon->balloon_diff = 0;
} else {
balloon->balloon_diff -= removedcnt;
}
}
static bool hv_balloon_handle_msg_size(HvBalloonReq *req, size_t minsize,
const char *msgname)
{
VMBusChanReq *vmreq = &req->vmreq;
uint32_t msglen = vmreq->msglen;
if (msglen >= minsize) {
return true;
}
warn_report("%s message too short (%u vs %zu), ignoring", msgname,
(unsigned int)msglen, minsize);
return false;
}
static void hv_balloon_handle_version_request(HvBalloon *balloon,
HvBalloonReq *req,
StateDesc *stdesc)
{
VMBusChanReq *vmreq = &req->vmreq;
struct dm_version_request *msgVr = vmreq->msg;
struct dm_version_response respVr;
if (balloon->state != S_VERSION) {
warn_report("unexpected DM_VERSION_REQUEST in %d state",
balloon->state);
return;
}
if (!hv_balloon_handle_msg_size(req, sizeof(*msgVr),
"DM_VERSION_REQUEST")) {
return;
}
trace_hv_balloon_incoming_version(msgVr->version.major_version,
msgVr->version.minor_version);
memset(&respVr, 0, sizeof(respVr));
respVr.hdr.type = DM_VERSION_RESPONSE;
respVr.hdr.size = sizeof(respVr);
respVr.hdr.trans_id = msgVr->hdr.trans_id;
respVr.is_accepted = msgVr->version.version >= DYNMEM_PROTOCOL_VERSION_1 &&
msgVr->version.version <= DYNMEM_PROTOCOL_VERSION_3;
hv_balloon_send_packet(vmreq->chan, (struct dm_message *)&respVr);
if (respVr.is_accepted) {
HV_BALLOON_STATE_DESC_SET(stdesc, S_CAPS);
}
}
static void hv_balloon_handle_caps_report(HvBalloon *balloon,
HvBalloonReq *req,
StateDesc *stdesc)
{
VMBusChanReq *vmreq = &req->vmreq;
struct dm_capabilities *msgCap = vmreq->msg;
struct dm_capabilities_resp_msg respCap;
if (balloon->state != S_CAPS) {
warn_report("unexpected DM_CAPABILITIES_REPORT in %d state",
balloon->state);
return;
}
if (!hv_balloon_handle_msg_size(req, sizeof(*msgCap),
"DM_CAPABILITIES_REPORT")) {
return;
}
trace_hv_balloon_incoming_caps(msgCap->caps.caps);
balloon->caps = msgCap->caps;
memset(&respCap, 0, sizeof(respCap));
respCap.hdr.type = DM_CAPABILITIES_RESPONSE;
respCap.hdr.size = sizeof(respCap);
respCap.hdr.trans_id = msgCap->hdr.trans_id;
respCap.is_accepted = 1;
respCap.hot_remove = 1;
respCap.suppress_pressure_reports = !balloon->status_report.enabled;
hv_balloon_send_packet(vmreq->chan, (struct dm_message *)&respCap);
timer_mod(&balloon->post_init_timer,
qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) +
HV_BALLOON_POST_INIT_WAIT);
HV_BALLOON_STATE_DESC_SET(stdesc, S_POST_INIT_WAIT);
}
static void hv_balloon_handle_status_report(HvBalloon *balloon,
HvBalloonReq *req)
{
VMBusChanReq *vmreq = &req->vmreq;
struct dm_status *msgStatus = vmreq->msg;
if (!hv_balloon_handle_msg_size(req, sizeof(*msgStatus),
"DM_STATUS_REPORT")) {
return;
}
if (!balloon->status_report.enabled) {
return;
}
balloon->status_report.committed = msgStatus->num_committed;
balloon->status_report.committed *= HV_BALLOON_PAGE_SIZE;
balloon->status_report.available = msgStatus->num_avail;
balloon->status_report.available *= HV_BALLOON_PAGE_SIZE;
balloon->status_report.received = true;
qapi_event_send_hv_balloon_status_report(balloon->status_report.committed,
balloon->status_report.available);
}
HvBalloonInfo *qmp_query_hv_balloon_status_report(Error **errp)
{
HvBalloon *balloon;
HvBalloonInfo *info;
balloon = HV_BALLOON(object_resolve_path_type("", TYPE_HV_BALLOON, NULL));
if (!balloon) {
error_setg(errp, "no %s device present", TYPE_HV_BALLOON);
return NULL;
}
if (!balloon->status_report.enabled) {
error_setg(errp, "guest memory status reporting not enabled");
return NULL;
}
if (!balloon->status_report.received) {
error_setg(errp, "no guest memory status report received yet");
return NULL;
}
info = g_malloc0(sizeof(*info));
info->committed = balloon->status_report.committed;
info->available = balloon->status_report.available;
return info;
}
static void hv_balloon_handle_unballoon_response(HvBalloon *balloon,
HvBalloonReq *req,
StateDesc *stdesc)
{
VMBusChanReq *vmreq = &req->vmreq;
struct dm_unballoon_response *msgUrR = vmreq->msg;
if (balloon->state != S_UNBALLOON_REPLY_WAIT) {
warn_report("unexpected DM_UNBALLOON_RESPONSE in %d state",
balloon->state);
return;
}
if (!hv_balloon_handle_msg_size(req, sizeof(*msgUrR),
"DM_UNBALLOON_RESPONSE"))
return;
trace_hv_balloon_incoming_unballoon(msgUrR->hdr.trans_id);
balloon->trans_id++;
if (balloon->hot_add_diff > 0) {
bool can_hot_add = balloon->caps.cap_bits.hot_add;
assert(can_hot_add);
HV_BALLOON_STATE_DESC_SET(stdesc, S_HOT_ADD_SETUP);
} else {
HV_BALLOON_STATE_DESC_SET(stdesc, S_IDLE);
}
}
static void hv_balloon_handle_hot_add_response(HvBalloon *balloon,
HvBalloonReq *req,
StateDesc *stdesc)
{
PageRange *hot_add_range = &balloon->hot_add_range;
VMBusChanReq *vmreq = &req->vmreq;
struct dm_hot_add_response *msgHaR = vmreq->msg;
OurRange *our_range;
if (balloon->state != S_HOT_ADD_REPLY_WAIT) {
warn_report("unexpected DM_HOT_ADD_RESPONSE in %d state",
balloon->state);
return;
}
assert(balloon->our_range);
our_range = OUR_RANGE(balloon->our_range);
if (!hv_balloon_handle_msg_size(req, sizeof(*msgHaR),
"DM_HOT_ADD_RESPONSE"))
return;
trace_hv_balloon_incoming_hot_add(msgHaR->hdr.trans_id, msgHaR->result,
msgHaR->page_count);
balloon->trans_id++;
if (msgHaR->result) {
if (msgHaR->page_count > balloon->ha_current_count) {
warn_report("DM_HOT_ADD_RESPONSE page count higher than requested (%"PRIu32" vs %"PRIu64")",
msgHaR->page_count, balloon->ha_current_count);
msgHaR->page_count = balloon->ha_current_count;
}
hvb_our_range_mark_added(our_range, msgHaR->page_count);
hot_add_range->start += msgHaR->page_count;
hot_add_range->count -= msgHaR->page_count;
}
if (!msgHaR->result || msgHaR->page_count < balloon->ha_current_count) {
/*
* the current planned range was only partially hot-added, take note
* how much of it remains and don't attempt any further hot adds
*/
our_range_mark_remaining_unusable(our_range);
goto ret_idle;
}
/* any pages remaining to hot-add in our range? */
if (hot_add_range->count > 0) {
HV_BALLOON_STATE_DESC_SET(stdesc, S_HOT_ADD_RB_WAIT);
return;
}
ret_idle:
HV_BALLOON_STATE_DESC_SET(stdesc, S_IDLE);
}
static void hv_balloon_handle_balloon_response(HvBalloon *balloon,
HvBalloonReq *req,
StateDesc *stdesc)
{
VMBusChanReq *vmreq = &req->vmreq;
struct dm_balloon_response *msgBR = vmreq->msg;
if (balloon->state != S_BALLOON_REPLY_WAIT) {
warn_report("unexpected DM_BALLOON_RESPONSE in %d state",
balloon->state);
return;
}
if (!hv_balloon_handle_msg_size(req, sizeof(*msgBR),
"DM_BALLOON_RESPONSE"))
return;
trace_hv_balloon_incoming_balloon(msgBR->hdr.trans_id, msgBR->range_count,
msgBR->more_pages);
if (vmreq->msglen < sizeof(*msgBR) +
(uint64_t)sizeof(msgBR->range_array[0]) * msgBR->range_count) {
warn_report("DM_BALLOON_RESPONSE too short for the range count");
return;
}
if (msgBR->range_count == 0) {
/* The guest is already at its minimum size */
balloon->balloon_diff = 0;
goto ret_end_trans;
} else {
hv_balloon_handle_remove_ranges(balloon,
msgBR->range_array,
msgBR->range_count);
}
/* More responses expected? */
if (msgBR->more_pages) {
return;
}
ret_end_trans:
balloon->trans_id++;
if (balloon->balloon_diff > 0) {
HV_BALLOON_STATE_DESC_SET(stdesc, S_BALLOON_RB_WAIT);
} else {
HV_BALLOON_STATE_DESC_SET(stdesc, S_IDLE);
}
}
static void hv_balloon_handle_packet(HvBalloon *balloon, HvBalloonReq *req,
StateDesc *stdesc)
{
VMBusChanReq *vmreq = &req->vmreq;
struct dm_message *msg = vmreq->msg;
if (vmreq->msglen < sizeof(msg->hdr)) {
return;
}
switch (msg->hdr.type) {
case DM_VERSION_REQUEST:
hv_balloon_handle_version_request(balloon, req, stdesc);
break;
case DM_CAPABILITIES_REPORT:
hv_balloon_handle_caps_report(balloon, req, stdesc);
break;
case DM_STATUS_REPORT:
hv_balloon_handle_status_report(balloon, req);
break;
case DM_MEM_HOT_ADD_RESPONSE:
hv_balloon_handle_hot_add_response(balloon, req, stdesc);
break;
case DM_UNBALLOON_RESPONSE:
hv_balloon_handle_unballoon_response(balloon, req, stdesc);
break;
case DM_BALLOON_RESPONSE:
hv_balloon_handle_balloon_response(balloon, req, stdesc);
break;
default:
warn_report("unknown DM message %u", msg->hdr.type);
break;
}
}
static bool hv_balloon_recv_channel(HvBalloon *balloon, StateDesc *stdesc)
{
VMBusChannel *chan;
HvBalloonReq *req;
if (balloon->state == S_WAIT_RESET ||
balloon->state == S_POST_RESET_CLOSED) {
return false;
}
chan = hv_balloon_get_channel(balloon);
if (vmbus_channel_recv_start(chan)) {
return false;
}
while ((req = vmbus_channel_recv_peek(chan, sizeof(*req)))) {
hv_balloon_handle_packet(balloon, req, stdesc);
vmbus_free_req(req);
vmbus_channel_recv_pop(chan);
if (stdesc->state != S_NO_CHANGE) {
break;
}
}
return vmbus_channel_recv_done(chan) > 0;
}
/* old state handler -> new state transition (potential) */
static bool hv_balloon_event_loop_state(HvBalloon *balloon)
{
StateDesc state_new = HV_BALLOON_STATE_DESC_INIT;
hv_balloon_handle_state(balloon, &state_new);
return hv_balloon_state_set(balloon, state_new.state, state_new.desc);
}
/* VMBus message -> new state transition (potential) */
static bool hv_balloon_event_loop_recv(HvBalloon *balloon)
{
StateDesc state_new = HV_BALLOON_STATE_DESC_INIT;
bool any_recv, state_changed;
any_recv = hv_balloon_recv_channel(balloon, &state_new);
state_changed = hv_balloon_state_set(balloon,
state_new.state, state_new.desc);
return state_changed || any_recv;
}
static void hv_balloon_event_loop(HvBalloon *balloon)
{
bool state_repeat, recv_repeat;
do {
state_repeat = hv_balloon_event_loop_state(balloon);
recv_repeat = hv_balloon_event_loop_recv(balloon);
} while (state_repeat || recv_repeat);
}
static void hv_balloon_vmdev_chan_notify(VMBusChannel *chan)
{
HvBalloon *balloon = HV_BALLOON(vmbus_channel_device(chan));
hv_balloon_event_loop(balloon);
}
static void hv_balloon_stat(void *opaque, BalloonInfo *info)
{
HvBalloon *balloon = opaque;
info->actual = (hv_balloon_total_ram(balloon) - balloon->removed_both_ctr)
<< HV_BALLOON_PFN_SHIFT;
}
static void hv_balloon_to_target(void *opaque, ram_addr_t target)
{
HvBalloon *balloon = opaque;
uint64_t target_pages = target >> HV_BALLOON_PFN_SHIFT;
if (!target_pages) {
return;
}
/*
* always set target_changed, even with unchanged target, as the user
* might be asking us to try again reaching it
*/
balloon->target = target_pages;
balloon->target_changed = true;
hv_balloon_event_loop(balloon);
}
static int hv_balloon_vmdev_open_channel(VMBusChannel *chan)
{
HvBalloon *balloon = HV_BALLOON(vmbus_channel_device(chan));
if (balloon->state != S_POST_RESET_CLOSED) {
warn_report("guest trying to open a DM channel in invalid %d state",
balloon->state);
return -EINVAL;
}
HV_BALLOON_SET_STATE(balloon, S_VERSION);
hv_balloon_event_loop(balloon);
return 0;
}
static void hv_balloon_vmdev_close_channel(VMBusChannel *chan)
{
HvBalloon *balloon = HV_BALLOON(vmbus_channel_device(chan));
timer_del(&balloon->post_init_timer);
/* Don't report stale data */
balloon->status_report.received = false;
HV_BALLOON_SET_STATE(balloon, S_WAIT_RESET);
hv_balloon_event_loop(balloon);
}
static void hv_balloon_post_init_timer(void *opaque)
{
HvBalloon *balloon = opaque;
if (balloon->state != S_POST_INIT_WAIT) {
return;
}
HV_BALLOON_SET_STATE(balloon, S_IDLE);
hv_balloon_event_loop(balloon);
}
static void hv_balloon_system_reset_unrealize_common(HvBalloon *balloon)
{
g_clear_pointer(&balloon->our_range, hvb_our_range_memslots_free);
}
static void hv_balloon_system_reset(void *opaque)
{
HvBalloon *balloon = HV_BALLOON(opaque);
hv_balloon_system_reset_unrealize_common(balloon);
}
static void hv_balloon_ensure_mr(HvBalloon *balloon)
{
MemoryRegion *hostmem_mr;
assert(balloon->hostmem);
if (balloon->mr) {
return;
}
hostmem_mr = host_memory_backend_get_memory(balloon->hostmem);
balloon->mr = g_new0(MemoryRegion, 1);
memory_region_init(balloon->mr, OBJECT(balloon), TYPE_HV_BALLOON,
memory_region_size(hostmem_mr));
balloon->mr->align = memory_region_get_alignment(hostmem_mr);
}
static void hv_balloon_free_mr(HvBalloon *balloon)
{
if (!balloon->mr) {
return;
}
object_unparent(OBJECT(balloon->mr));
g_clear_pointer(&balloon->mr, g_free);
}
static void hv_balloon_vmdev_realize(VMBusDevice *vdev, Error **errp)
{
ERRP_GUARD();
HvBalloon *balloon = HV_BALLOON(vdev);
int ret;
balloon->state = S_WAIT_RESET;
ret = qemu_add_balloon_handler(hv_balloon_to_target, hv_balloon_stat,
balloon);
if (ret < 0) {
/* This also protects against having multiple hv-balloon instances */
error_setg(errp, "Only one balloon device is supported");
return;
}
if (balloon->hostmem) {
if (host_memory_backend_is_mapped(balloon->hostmem)) {
Object *obj = OBJECT(balloon->hostmem);
error_setg(errp, "'%s' property specifies a busy memdev: %s",
HV_BALLOON_MEMDEV_PROP,
object_get_canonical_path_component(obj));
goto out_balloon_handler;
}
hv_balloon_ensure_mr(balloon);
/* This is rather unlikely to happen, but let's still check for it. */
if (!QEMU_IS_ALIGNED(memory_region_size(balloon->mr),
HV_BALLOON_PAGE_SIZE)) {
error_setg(errp, "'%s' property memdev size has to be a multiple of 0x%" PRIx64,
HV_BALLOON_MEMDEV_PROP, (uint64_t)HV_BALLOON_PAGE_SIZE);
goto out_balloon_handler;
}
host_memory_backend_set_mapped(balloon->hostmem, true);
vmstate_register_ram(host_memory_backend_get_memory(balloon->hostmem),
DEVICE(balloon));
} else if (balloon->addr) {
error_setg(errp, "'%s' property must not be set without a memdev",
HV_BALLOON_MEMDEV_PROP);
goto out_balloon_handler;
}
timer_init_ms(&balloon->post_init_timer, QEMU_CLOCK_VIRTUAL,
hv_balloon_post_init_timer, balloon);
qemu_register_reset(hv_balloon_system_reset, balloon);
return;
out_balloon_handler:
qemu_remove_balloon_handler(balloon);
}
/*
* VMBus device reset has to be implemented in case the guest decides to
* disconnect and reconnect to the VMBus without rebooting the whole system.
*
* However, the hot-added memory can't be removed here as Windows keeps on using
* it until the system is restarted, even after disconnecting from the VMBus.
*/
static void hv_balloon_vmdev_reset(VMBusDevice *vdev)
{
HvBalloon *balloon = HV_BALLOON(vdev);
if (balloon->state == S_POST_RESET_CLOSED) {
return;
}
if (balloon->our_range) {
hvb_our_range_clear_removed_trees(OUR_RANGE(balloon->our_range));
}
hvb_page_range_tree_destroy(&balloon->removed_guest);
hvb_page_range_tree_destroy(&balloon->removed_both);
hvb_page_range_tree_init(&balloon->removed_guest);
hvb_page_range_tree_init(&balloon->removed_both);
balloon->trans_id = 0;
balloon->removed_guest_ctr = 0;
balloon->removed_both_ctr = 0;
HV_BALLOON_SET_STATE(balloon, S_POST_RESET_CLOSED);
hv_balloon_event_loop(balloon);
}
/*
* Clean up things that were (possibly) allocated pre-realization, for example
* from memory_device_pre_plug(), so we don't leak them if the device don't
* actually get realized in the end.
*/
static void hv_balloon_unrealize_finalize_common(HvBalloon *balloon)
{
hv_balloon_free_mr(balloon);
balloon->addr = 0;
balloon->memslot_count = 0;
}
static void hv_balloon_vmdev_unrealize(VMBusDevice *vdev)
{
HvBalloon *balloon = HV_BALLOON(vdev);
qemu_unregister_reset(hv_balloon_system_reset, balloon);
hv_balloon_system_reset_unrealize_common(balloon);
qemu_remove_balloon_handler(balloon);
if (balloon->hostmem) {
vmstate_unregister_ram(host_memory_backend_get_memory(balloon->hostmem),
DEVICE(balloon));
host_memory_backend_set_mapped(balloon->hostmem, false);
}
hvb_page_range_tree_destroy(&balloon->removed_guest);
hvb_page_range_tree_destroy(&balloon->removed_both);
hv_balloon_unrealize_finalize_common(balloon);
}
static uint64_t hv_balloon_md_get_addr(const MemoryDeviceState *md)
{
return object_property_get_uint(OBJECT(md), HV_BALLOON_ADDR_PROP,
&error_abort);
}
static void hv_balloon_md_set_addr(MemoryDeviceState *md, uint64_t addr,
Error **errp)
{
object_property_set_uint(OBJECT(md), HV_BALLOON_ADDR_PROP, addr, errp);
}
static MemoryRegion *hv_balloon_md_get_memory_region(MemoryDeviceState *md,
Error **errp)
{
HvBalloon *balloon = HV_BALLOON(md);
if (!balloon->hostmem) {
return NULL;
}
hv_balloon_ensure_mr(balloon);
return balloon->mr;
}
static uint64_t hv_balloon_md_get_min_alignment(const MemoryDeviceState *md)
{
/*
* The VM can indicate an alignment up to 32 GiB. Memory device core can
* usually only handle/guarantee 1 GiB alignment. The user will have to
* specify a larger maxmem eventually.
*
* The memory device core will warn the user in case maxmem might have to be
* increased and will fail plugging the device if there is not sufficient
* space after alignment.
*
* TODO: we could do the alignment ourselves in a slightly bigger region.
* But this feels better, although the warning might be annoying. Maybe
* we can optimize that in the future (e.g., with such a device on the
* cmdline place/size the device memory region differently.
*/
return 32 * GiB;
}
static void hv_balloon_md_fill_device_info(const MemoryDeviceState *md,
MemoryDeviceInfo *info)
{
HvBalloonDeviceInfo *hi = g_new0(HvBalloonDeviceInfo, 1);
const HvBalloon *balloon = HV_BALLOON(md);
DeviceState *dev = DEVICE(md);
if (dev->id) {
hi->id = g_strdup(dev->id);
}
if (balloon->hostmem) {
hi->memdev = object_get_canonical_path(OBJECT(balloon->hostmem));
hi->memaddr = balloon->addr;
hi->has_memaddr = true;
hi->max_size = memory_region_size(balloon->mr);
/* TODO: expose current provided size or something else? */
} else {
hi->max_size = 0;
}
info->u.hv_balloon.data = hi;
info->type = MEMORY_DEVICE_INFO_KIND_HV_BALLOON;
}
static void hv_balloon_decide_memslots(MemoryDeviceState *md,
unsigned int limit)
{
HvBalloon *balloon = HV_BALLOON(md);
MemoryRegion *hostmem_mr;
uint64_t region_size, memslot_size, memslots;
/* We're called exactly once, before realizing the device. */
assert(!balloon->memslot_count);
/* We should not be called if we don't have a memory backend */
assert(balloon->hostmem);
hostmem_mr = host_memory_backend_get_memory(balloon->hostmem);
region_size = memory_region_size(hostmem_mr);
assert(region_size > 0);
memslot_size = QEMU_ALIGN_UP(region_size / limit,
HV_BALLOON_HA_MEMSLOT_SIZE_ALIGN);
memslots = QEMU_ALIGN_UP(region_size, memslot_size) / memslot_size;
if (memslots > 1) {
balloon->memslot_size = memslot_size;
} else {
balloon->memslot_size = region_size;
}
assert(memslots <= UINT_MAX);
balloon->memslot_count = memslots;
}
static unsigned int hv_balloon_get_memslots(MemoryDeviceState *md)
{
const HvBalloon *balloon = HV_BALLOON(md);
/* We're called after setting the suggested limit. */
assert(balloon->memslot_count > 0);
return balloon->memslot_count;
}
static void hv_balloon_init(Object *obj)
{
}
static void hv_balloon_finalize(Object *obj)
{
HvBalloon *balloon = HV_BALLOON(obj);
hv_balloon_unrealize_finalize_common(balloon);
}
static Property hv_balloon_properties[] = {
DEFINE_PROP_BOOL("status-report", HvBalloon,
status_report.enabled, false),
/* MEMORY_DEVICE props */
DEFINE_PROP_LINK(HV_BALLOON_MEMDEV_PROP, HvBalloon, hostmem,
TYPE_MEMORY_BACKEND, HostMemoryBackend *),
DEFINE_PROP_UINT64(HV_BALLOON_ADDR_PROP, HvBalloon, addr, 0),
DEFINE_PROP_END_OF_LIST(),
};
static void hv_balloon_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
VMBusDeviceClass *vdc = VMBUS_DEVICE_CLASS(klass);
MemoryDeviceClass *mdc = MEMORY_DEVICE_CLASS(klass);
device_class_set_props(dc, hv_balloon_properties);
qemu_uuid_parse(HV_BALLOON_GUID, &vdc->classid);
set_bit(DEVICE_CATEGORY_MISC, dc->categories);
vdc->vmdev_realize = hv_balloon_vmdev_realize;
vdc->vmdev_unrealize = hv_balloon_vmdev_unrealize;
vdc->vmdev_reset = hv_balloon_vmdev_reset;
vdc->open_channel = hv_balloon_vmdev_open_channel;
vdc->close_channel = hv_balloon_vmdev_close_channel;
vdc->chan_notify_cb = hv_balloon_vmdev_chan_notify;
mdc->get_addr = hv_balloon_md_get_addr;
mdc->set_addr = hv_balloon_md_set_addr;
mdc->get_plugged_size = memory_device_get_region_size;
mdc->get_memory_region = hv_balloon_md_get_memory_region;
mdc->decide_memslots = hv_balloon_decide_memslots;
mdc->get_memslots = hv_balloon_get_memslots;
mdc->get_min_alignment = hv_balloon_md_get_min_alignment;
mdc->fill_device_info = hv_balloon_md_fill_device_info;
}