diff options
Diffstat (limited to 'hw/hyperv/hv-balloon-our_range_memslots.c')
| -rw-r--r-- | hw/hyperv/hv-balloon-our_range_memslots.c | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/hw/hyperv/hv-balloon-our_range_memslots.c b/hw/hyperv/hv-balloon-our_range_memslots.c new file mode 100644 index 0000000000..99bae870f3 --- /dev/null +++ b/hw/hyperv/hv-balloon-our_range_memslots.c @@ -0,0 +1,201 @@ +/* + * 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 "hv-balloon-our_range_memslots.h" +#include "trace.h" + +/* OurRange */ +static void our_range_init(OurRange *our_range, uint64_t start, uint64_t count) +{ + assert(count <= UINT64_MAX - start); + our_range->range.start = start; + our_range->range.count = count; + + hvb_page_range_tree_init(&our_range->removed_guest); + hvb_page_range_tree_init(&our_range->removed_both); + + /* mark the whole range as unused but for potential use */ + our_range->added = 0; + our_range->unusable_tail = 0; +} + +static void our_range_destroy(OurRange *our_range) +{ + hvb_page_range_tree_destroy(&our_range->removed_guest); + hvb_page_range_tree_destroy(&our_range->removed_both); +} + +void hvb_our_range_clear_removed_trees(OurRange *our_range) +{ + hvb_page_range_tree_destroy(&our_range->removed_guest); + hvb_page_range_tree_destroy(&our_range->removed_both); + hvb_page_range_tree_init(&our_range->removed_guest); + hvb_page_range_tree_init(&our_range->removed_both); +} + +void hvb_our_range_mark_added(OurRange *our_range, uint64_t additional_size) +{ + assert(additional_size <= UINT64_MAX - our_range->added); + + our_range->added += additional_size; + + assert(our_range->added <= UINT64_MAX - our_range->unusable_tail); + assert(our_range->added + our_range->unusable_tail <= + our_range->range.count); +} + +/* OurRangeMemslots */ +static void our_range_memslots_init_slots(OurRangeMemslots *our_range, + MemoryRegion *backing_mr, + Object *memslot_owner) +{ + OurRangeMemslotsSlots *memslots = &our_range->slots; + unsigned int idx; + uint64_t memslot_offset; + + assert(memslots->count > 0); + memslots->slots = g_new0(MemoryRegion, memslots->count); + + /* Initialize our memslots, but don't map them yet. */ + assert(memslots->size_each > 0); + for (idx = 0, memslot_offset = 0; idx < memslots->count; + idx++, memslot_offset += memslots->size_each) { + uint64_t memslot_size; + g_autofree char *name = NULL; + + /* The size of the last memslot might be smaller. */ + if (idx == memslots->count - 1) { + uint64_t region_size; + + assert(our_range->mr); + region_size = memory_region_size(our_range->mr); + memslot_size = region_size - memslot_offset; + } else { + memslot_size = memslots->size_each; + } + + name = g_strdup_printf("memslot-%u", idx); + memory_region_init_alias(&memslots->slots[idx], memslot_owner, name, + backing_mr, memslot_offset, memslot_size); + /* + * We want to be able to atomically and efficiently activate/deactivate + * individual memslots without affecting adjacent memslots in memory + * notifiers. + */ + memory_region_set_unmergeable(&memslots->slots[idx], true); + } + + memslots->mapped_count = 0; +} + +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) +{ + OurRangeMemslots *our_range; + + our_range = g_malloc(sizeof(*our_range)); + our_range_init(&our_range->range, + addr / HV_BALLOON_PAGE_SIZE, + memory_region_size(parent_mr) / HV_BALLOON_PAGE_SIZE); + our_range->slots.size_each = memslot_size; + our_range->slots.count = memslot_count; + our_range->mr = parent_mr; + our_range_memslots_init_slots(our_range, backing_mr, memslot_owner); + + return our_range; +} + +static void our_range_memslots_free_memslots(OurRangeMemslots *our_range) +{ + OurRangeMemslotsSlots *memslots = &our_range->slots; + unsigned int idx; + uint64_t offset; + + memory_region_transaction_begin(); + for (idx = 0, offset = 0; idx < memslots->mapped_count; + idx++, offset += memslots->size_each) { + trace_hv_balloon_unmap_slot(idx, memslots->count, offset); + assert(memory_region_is_mapped(&memslots->slots[idx])); + memory_region_del_subregion(our_range->mr, &memslots->slots[idx]); + } + memory_region_transaction_commit(); + + for (idx = 0; idx < memslots->count; idx++) { + object_unparent(OBJECT(&memslots->slots[idx])); + } + + g_clear_pointer(&our_range->slots.slots, g_free); +} + +void hvb_our_range_memslots_free(OurRangeMemslots *our_range) +{ + OurRangeMemslotsSlots *memslots = &our_range->slots; + MemoryRegion *hostmem_mr; + RAMBlock *rb; + + assert(our_range->slots.count > 0); + assert(our_range->slots.slots); + + hostmem_mr = memslots->slots[0].alias; + rb = hostmem_mr->ram_block; + ram_block_discard_range(rb, 0, qemu_ram_get_used_length(rb)); + + our_range_memslots_free_memslots(our_range); + our_range_destroy(&our_range->range); + g_free(our_range); +} + +void hvb_our_range_memslots_ensure_mapped_additional(OurRangeMemslots *our_range, + uint64_t additional_map_size) +{ + OurRangeMemslotsSlots *memslots = &our_range->slots; + uint64_t total_map_size; + unsigned int idx; + uint64_t offset; + + total_map_size = (our_range->range.added + additional_map_size) * + HV_BALLOON_PAGE_SIZE; + idx = memslots->mapped_count; + assert(memslots->size_each > 0); + offset = idx * memslots->size_each; + + /* + * Activate all memslots covered by the newly added region in a single + * transaction. + */ + memory_region_transaction_begin(); + for ( ; idx < memslots->count; + idx++, offset += memslots->size_each) { + /* + * If this memslot starts beyond or at the end of the range to map so + * does every next one. + */ + if (offset >= total_map_size) { + break; + } + + /* + * Instead of enabling/disabling memslot, we add/remove them. This + * should make address space updates faster, because we don't have to + * loop over many disabled subregions. + */ + trace_hv_balloon_map_slot(idx, memslots->count, offset); + assert(!memory_region_is_mapped(&memslots->slots[idx])); + memory_region_add_subregion(our_range->mr, offset, + &memslots->slots[idx]); + + memslots->mapped_count++; + } + memory_region_transaction_commit(); +} |