qemu-e2k/hw/hyperv/hv-balloon-our_range_memslots.h
Maciej S. Szmigiero 99a4706ae8 Add Hyper-V Dynamic Memory Protocol driver (hv-balloon) hot-add support
One of advantages of using this protocol over ACPI-based PC DIMM hotplug is
that it allows hot-adding memory in much smaller granularity because the
ACPI DIMM slot limit does not apply.

In order to enable this functionality a new memory backend needs to be
created and provided to the driver via the "memdev" parameter.

This can be achieved by, for example, adding
"-object memory-backend-ram,id=mem1,size=32G" to the QEMU command line and
then instantiating the driver with "memdev=mem1" parameter.

The device will try to use multiple memslots to cover the memory backend in
order to reduce the size of metadata for the not-yet-hot-added part of the
memory backend.

Co-developed-by: David Hildenbrand <david@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
2023-11-06 14:08:10 +01:00

111 lines
3.2 KiB
C

/*
* 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.
*/
#ifndef HW_HYPERV_HV_BALLOON_OUR_RANGE_MEMSLOTS_H
#define HW_HYPERV_HV_BALLOON_OUR_RANGE_MEMSLOTS_H
#include "qemu/osdep.h"
#include "exec/memory.h"
#include "qom/object.h"
#include "hv-balloon-page_range_tree.h"
/* OurRange */
#define OUR_RANGE(ptr) ((OurRange *)(ptr))
/* "our range" means the memory range owned by this driver (for hot-adding) */
typedef struct OurRange {
PageRange range;
/* How many pages were hot-added to the guest */
uint64_t added;
/* Pages at the end not currently usable */
uint64_t unusable_tail;
/* Memory removed from the guest */
PageRangeTree removed_guest, removed_both;
} OurRange;
static inline uint64_t our_range_get_remaining_start(OurRange *our_range)
{
return our_range->range.start + our_range->added;
}
static inline uint64_t our_range_get_remaining_size(OurRange *our_range)
{
return our_range->range.count - our_range->added - our_range->unusable_tail;
}
void hvb_our_range_mark_added(OurRange *our_range, uint64_t additional_size);
static inline void our_range_mark_remaining_unusable(OurRange *our_range)
{
our_range->unusable_tail = our_range->range.count - our_range->added;
}
static inline PageRangeTree our_range_get_removed_tree(OurRange *our_range,
bool both)
{
if (both) {
return our_range->removed_both;
} else {
return our_range->removed_guest;
}
}
static inline bool our_range_is_removed_tree_empty(OurRange *our_range,
bool both)
{
if (both) {
return page_range_tree_is_empty(our_range->removed_both);
} else {
return page_range_tree_is_empty(our_range->removed_guest);
}
}
void hvb_our_range_clear_removed_trees(OurRange *our_range);
/* OurRangeMemslots */
typedef struct OurRangeMemslotsSlots {
/* Nominal size of each memslot (the last one might be smaller) */
uint64_t size_each;
/* Slots array and its element count */
MemoryRegion *slots;
unsigned int count;
/* How many slots are currently mapped */
unsigned int mapped_count;
} OurRangeMemslotsSlots;
typedef struct OurRangeMemslots {
OurRange range;
/* Memslots covering our range */
OurRangeMemslotsSlots slots;
MemoryRegion *mr;
} OurRangeMemslots;
OurRangeMemslots *hvb_our_range_memslots_new(uint64_t addr,
MemoryRegion *parent_mr,
MemoryRegion *backing_mr,
Object *memslot_owner,
unsigned int memslot_count,
uint64_t memslot_size);
void hvb_our_range_memslots_free(OurRangeMemslots *our_range);
G_DEFINE_AUTOPTR_CLEANUP_FUNC(OurRangeMemslots, hvb_our_range_memslots_free)
void hvb_our_range_memslots_ensure_mapped_additional(OurRangeMemslots *our_range,
uint64_t additional_map_size);
#endif