diff options
Diffstat (limited to 'system/ram-block-attributes.c')
| -rw-r--r-- | system/ram-block-attributes.c | 444 |
1 files changed, 444 insertions, 0 deletions
diff --git a/system/ram-block-attributes.c b/system/ram-block-attributes.c new file mode 100644 index 0000000..68e8a02 --- /dev/null +++ b/system/ram-block-attributes.c @@ -0,0 +1,444 @@ +/* + * QEMU ram block attributes + * + * Copyright Intel + * + * Author: + * Chenyi Qiang <chenyi.qiang@intel.com> + * + * SPDX-License-Identifier: GPL-2.0-or-later + */ + +#include "qemu/osdep.h" +#include "qemu/error-report.h" +#include "system/ramblock.h" +#include "trace.h" + +OBJECT_DEFINE_SIMPLE_TYPE_WITH_INTERFACES(RamBlockAttributes, + ram_block_attributes, + RAM_BLOCK_ATTRIBUTES, + OBJECT, + { TYPE_RAM_DISCARD_MANAGER }, + { }) + +static size_t +ram_block_attributes_get_block_size(const RamBlockAttributes *attr) +{ + /* + * Because page conversion could be manipulated in the size of at least 4K + * or 4K aligned, Use the host page size as the granularity to track the + * memory attribute. + */ + g_assert(attr && attr->ram_block); + g_assert(attr->ram_block->page_size == qemu_real_host_page_size()); + return attr->ram_block->page_size; +} + + +static bool +ram_block_attributes_rdm_is_populated(const RamDiscardManager *rdm, + const MemoryRegionSection *section) +{ + const RamBlockAttributes *attr = RAM_BLOCK_ATTRIBUTES(rdm); + const size_t block_size = ram_block_attributes_get_block_size(attr); + const uint64_t first_bit = section->offset_within_region / block_size; + const uint64_t last_bit = + first_bit + int128_get64(section->size) / block_size - 1; + unsigned long first_discarded_bit; + + first_discarded_bit = find_next_zero_bit(attr->bitmap, last_bit + 1, + first_bit); + return first_discarded_bit > last_bit; +} + +typedef int (*ram_block_attributes_section_cb)(MemoryRegionSection *s, + void *arg); + +static int +ram_block_attributes_notify_populate_cb(MemoryRegionSection *section, + void *arg) +{ + RamDiscardListener *rdl = arg; + + return rdl->notify_populate(rdl, section); +} + +static int +ram_block_attributes_notify_discard_cb(MemoryRegionSection *section, + void *arg) +{ + RamDiscardListener *rdl = arg; + + rdl->notify_discard(rdl, section); + return 0; +} + +static int +ram_block_attributes_for_each_populated_section(const RamBlockAttributes *attr, + MemoryRegionSection *section, + void *arg, + ram_block_attributes_section_cb cb) +{ + unsigned long first_bit, last_bit; + uint64_t offset, size; + const size_t block_size = ram_block_attributes_get_block_size(attr); + int ret = 0; + + first_bit = section->offset_within_region / block_size; + first_bit = find_next_bit(attr->bitmap, attr->bitmap_size, + first_bit); + + while (first_bit < attr->bitmap_size) { + MemoryRegionSection tmp = *section; + + offset = first_bit * block_size; + last_bit = find_next_zero_bit(attr->bitmap, attr->bitmap_size, + first_bit + 1) - 1; + size = (last_bit - first_bit + 1) * block_size; + + if (!memory_region_section_intersect_range(&tmp, offset, size)) { + break; + } + + ret = cb(&tmp, arg); + if (ret) { + error_report("%s: Failed to notify RAM discard listener: %s", + __func__, strerror(-ret)); + break; + } + + first_bit = find_next_bit(attr->bitmap, attr->bitmap_size, + last_bit + 2); + } + + return ret; +} + +static int +ram_block_attributes_for_each_discarded_section(const RamBlockAttributes *attr, + MemoryRegionSection *section, + void *arg, + ram_block_attributes_section_cb cb) +{ + unsigned long first_bit, last_bit; + uint64_t offset, size; + const size_t block_size = ram_block_attributes_get_block_size(attr); + int ret = 0; + + first_bit = section->offset_within_region / block_size; + first_bit = find_next_zero_bit(attr->bitmap, attr->bitmap_size, + first_bit); + + while (first_bit < attr->bitmap_size) { + MemoryRegionSection tmp = *section; + + offset = first_bit * block_size; + last_bit = find_next_bit(attr->bitmap, attr->bitmap_size, + first_bit + 1) - 1; + size = (last_bit - first_bit + 1) * block_size; + + if (!memory_region_section_intersect_range(&tmp, offset, size)) { + break; + } + + ret = cb(&tmp, arg); + if (ret) { + error_report("%s: Failed to notify RAM discard listener: %s", + __func__, strerror(-ret)); + break; + } + + first_bit = find_next_zero_bit(attr->bitmap, + attr->bitmap_size, + last_bit + 2); + } + + return ret; +} + +static uint64_t +ram_block_attributes_rdm_get_min_granularity(const RamDiscardManager *rdm, + const MemoryRegion *mr) +{ + const RamBlockAttributes *attr = RAM_BLOCK_ATTRIBUTES(rdm); + + g_assert(mr == attr->ram_block->mr); + return ram_block_attributes_get_block_size(attr); +} + +static void +ram_block_attributes_rdm_register_listener(RamDiscardManager *rdm, + RamDiscardListener *rdl, + MemoryRegionSection *section) +{ + RamBlockAttributes *attr = RAM_BLOCK_ATTRIBUTES(rdm); + int ret; + + g_assert(section->mr == attr->ram_block->mr); + rdl->section = memory_region_section_new_copy(section); + + QLIST_INSERT_HEAD(&attr->rdl_list, rdl, next); + + ret = ram_block_attributes_for_each_populated_section(attr, section, rdl, + ram_block_attributes_notify_populate_cb); + if (ret) { + error_report("%s: Failed to register RAM discard listener: %s", + __func__, strerror(-ret)); + exit(1); + } +} + +static void +ram_block_attributes_rdm_unregister_listener(RamDiscardManager *rdm, + RamDiscardListener *rdl) +{ + RamBlockAttributes *attr = RAM_BLOCK_ATTRIBUTES(rdm); + int ret; + + g_assert(rdl->section); + g_assert(rdl->section->mr == attr->ram_block->mr); + + if (rdl->double_discard_supported) { + rdl->notify_discard(rdl, rdl->section); + } else { + ret = ram_block_attributes_for_each_populated_section(attr, + rdl->section, rdl, ram_block_attributes_notify_discard_cb); + if (ret) { + error_report("%s: Failed to unregister RAM discard listener: %s", + __func__, strerror(-ret)); + exit(1); + } + } + + memory_region_section_free_copy(rdl->section); + rdl->section = NULL; + QLIST_REMOVE(rdl, next); +} + +typedef struct RamBlockAttributesReplayData { + ReplayRamDiscardState fn; + void *opaque; +} RamBlockAttributesReplayData; + +static int ram_block_attributes_rdm_replay_cb(MemoryRegionSection *section, + void *arg) +{ + RamBlockAttributesReplayData *data = arg; + + return data->fn(section, data->opaque); +} + +static int +ram_block_attributes_rdm_replay_populated(const RamDiscardManager *rdm, + MemoryRegionSection *section, + ReplayRamDiscardState replay_fn, + void *opaque) +{ + RamBlockAttributes *attr = RAM_BLOCK_ATTRIBUTES(rdm); + RamBlockAttributesReplayData data = { .fn = replay_fn, .opaque = opaque }; + + g_assert(section->mr == attr->ram_block->mr); + return ram_block_attributes_for_each_populated_section(attr, section, &data, + ram_block_attributes_rdm_replay_cb); +} + +static int +ram_block_attributes_rdm_replay_discarded(const RamDiscardManager *rdm, + MemoryRegionSection *section, + ReplayRamDiscardState replay_fn, + void *opaque) +{ + RamBlockAttributes *attr = RAM_BLOCK_ATTRIBUTES(rdm); + RamBlockAttributesReplayData data = { .fn = replay_fn, .opaque = opaque }; + + g_assert(section->mr == attr->ram_block->mr); + return ram_block_attributes_for_each_discarded_section(attr, section, &data, + ram_block_attributes_rdm_replay_cb); +} + +static bool +ram_block_attributes_is_valid_range(RamBlockAttributes *attr, uint64_t offset, + uint64_t size) +{ + MemoryRegion *mr = attr->ram_block->mr; + + g_assert(mr); + + uint64_t region_size = memory_region_size(mr); + const size_t block_size = ram_block_attributes_get_block_size(attr); + + if (!QEMU_IS_ALIGNED(offset, block_size) || + !QEMU_IS_ALIGNED(size, block_size)) { + return false; + } + if (offset + size <= offset) { + return false; + } + if (offset + size > region_size) { + return false; + } + return true; +} + +static void ram_block_attributes_notify_discard(RamBlockAttributes *attr, + uint64_t offset, + uint64_t size) +{ + RamDiscardListener *rdl; + + QLIST_FOREACH(rdl, &attr->rdl_list, next) { + MemoryRegionSection tmp = *rdl->section; + + if (!memory_region_section_intersect_range(&tmp, offset, size)) { + continue; + } + rdl->notify_discard(rdl, &tmp); + } +} + +static int +ram_block_attributes_notify_populate(RamBlockAttributes *attr, + uint64_t offset, uint64_t size) +{ + RamDiscardListener *rdl; + int ret = 0; + + QLIST_FOREACH(rdl, &attr->rdl_list, next) { + MemoryRegionSection tmp = *rdl->section; + + if (!memory_region_section_intersect_range(&tmp, offset, size)) { + continue; + } + ret = rdl->notify_populate(rdl, &tmp); + if (ret) { + break; + } + } + + return ret; +} + +int ram_block_attributes_state_change(RamBlockAttributes *attr, + uint64_t offset, uint64_t size, + bool to_discard) +{ + const size_t block_size = ram_block_attributes_get_block_size(attr); + const unsigned long first_bit = offset / block_size; + const unsigned long nbits = size / block_size; + const unsigned long last_bit = first_bit + nbits - 1; + const bool is_discarded = find_next_bit(attr->bitmap, attr->bitmap_size, + first_bit) > last_bit; + const bool is_populated = find_next_zero_bit(attr->bitmap, + attr->bitmap_size, first_bit) > last_bit; + unsigned long bit; + int ret = 0; + + if (!ram_block_attributes_is_valid_range(attr, offset, size)) { + error_report("%s, invalid range: offset 0x%" PRIx64 ", size " + "0x%" PRIx64, __func__, offset, size); + return -EINVAL; + } + + trace_ram_block_attributes_state_change(offset, size, + is_discarded ? "discarded" : + is_populated ? "populated" : + "mixture", + to_discard ? "discarded" : + "populated"); + if (to_discard) { + if (is_discarded) { + /* Already private */ + } else if (is_populated) { + /* Completely shared */ + bitmap_clear(attr->bitmap, first_bit, nbits); + ram_block_attributes_notify_discard(attr, offset, size); + } else { + /* Unexpected mixture: process individual blocks */ + for (bit = first_bit; bit < first_bit + nbits; bit++) { + if (!test_bit(bit, attr->bitmap)) { + continue; + } + clear_bit(bit, attr->bitmap); + ram_block_attributes_notify_discard(attr, bit * block_size, + block_size); + } + } + } else { + if (is_populated) { + /* Already shared */ + } else if (is_discarded) { + /* Completely private */ + bitmap_set(attr->bitmap, first_bit, nbits); + ret = ram_block_attributes_notify_populate(attr, offset, size); + } else { + /* Unexpected mixture: process individual blocks */ + for (bit = first_bit; bit < first_bit + nbits; bit++) { + if (test_bit(bit, attr->bitmap)) { + continue; + } + set_bit(bit, attr->bitmap); + ret = ram_block_attributes_notify_populate(attr, + bit * block_size, + block_size); + if (ret) { + break; + } + } + } + } + + return ret; +} + +RamBlockAttributes *ram_block_attributes_create(RAMBlock *ram_block) +{ + const int block_size = qemu_real_host_page_size(); + RamBlockAttributes *attr; + MemoryRegion *mr = ram_block->mr; + + attr = RAM_BLOCK_ATTRIBUTES(object_new(TYPE_RAM_BLOCK_ATTRIBUTES)); + + attr->ram_block = ram_block; + if (memory_region_set_ram_discard_manager(mr, RAM_DISCARD_MANAGER(attr))) { + object_unref(OBJECT(attr)); + return NULL; + } + attr->bitmap_size = + ROUND_UP(int128_get64(mr->size), block_size) / block_size; + attr->bitmap = bitmap_new(attr->bitmap_size); + + return attr; +} + +void ram_block_attributes_destroy(RamBlockAttributes *attr) +{ + g_assert(attr); + + g_free(attr->bitmap); + memory_region_set_ram_discard_manager(attr->ram_block->mr, NULL); + object_unref(OBJECT(attr)); +} + +static void ram_block_attributes_init(Object *obj) +{ + RamBlockAttributes *attr = RAM_BLOCK_ATTRIBUTES(obj); + + QLIST_INIT(&attr->rdl_list); +} + +static void ram_block_attributes_finalize(Object *obj) +{ +} + +static void ram_block_attributes_class_init(ObjectClass *klass, + const void *data) +{ + RamDiscardManagerClass *rdmc = RAM_DISCARD_MANAGER_CLASS(klass); + + rdmc->get_min_granularity = ram_block_attributes_rdm_get_min_granularity; + rdmc->register_listener = ram_block_attributes_rdm_register_listener; + rdmc->unregister_listener = ram_block_attributes_rdm_unregister_listener; + rdmc->is_populated = ram_block_attributes_rdm_is_populated; + rdmc->replay_populated = ram_block_attributes_rdm_replay_populated; + rdmc->replay_discarded = ram_block_attributes_rdm_replay_discarded; +} |