diff options
Diffstat (limited to 'hw/hyperv/hv-balloon.c')
| -rw-r--r-- | hw/hyperv/hv-balloon.c | 1769 |
1 files changed, 1769 insertions, 0 deletions
diff --git a/hw/hyperv/hv-balloon.c b/hw/hyperv/hv-balloon.c new file mode 100644 index 0000000000..66f297c1d7 --- /dev/null +++ b/hw/hyperv/hv-balloon.c @@ -0,0 +1,1769 @@ +/* + * 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 "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, §ion, + 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)); + + /* + * 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. + */ + balloon->mr->align = MAX(32 * GiB, 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 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->fill_device_info = hv_balloon_md_fill_device_info; +} |