| /* |
| * Dirtyrate implement code |
| * |
| * Copyright (c) 2020 HUAWEI TECHNOLOGIES CO.,LTD. |
| * |
| * Authors: |
| * Chuan Zheng <zhengchuan@huawei.com> |
| * |
| * 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 <zlib.h> |
| #include "qapi/error.h" |
| #include "cpu.h" |
| #include "exec/ramblock.h" |
| #include "qemu/rcu_queue.h" |
| #include "qapi/qapi-commands-migration.h" |
| #include "ram.h" |
| #include "trace.h" |
| #include "dirtyrate.h" |
| |
| static int CalculatingState = DIRTY_RATE_STATUS_UNSTARTED; |
| static struct DirtyRateStat DirtyStat; |
| |
| static int64_t set_sample_page_period(int64_t msec, int64_t initial_time) |
| { |
| int64_t current_time; |
| |
| current_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); |
| if ((current_time - initial_time) >= msec) { |
| msec = current_time - initial_time; |
| } else { |
| g_usleep((msec + initial_time - current_time) * 1000); |
| } |
| |
| return msec; |
| } |
| |
| static bool is_sample_period_valid(int64_t sec) |
| { |
| if (sec < MIN_FETCH_DIRTYRATE_TIME_SEC || |
| sec > MAX_FETCH_DIRTYRATE_TIME_SEC) { |
| return false; |
| } |
| |
| return true; |
| } |
| |
| static int dirtyrate_set_state(int *state, int old_state, int new_state) |
| { |
| assert(new_state < DIRTY_RATE_STATUS__MAX); |
| trace_dirtyrate_set_state(DirtyRateStatus_str(new_state)); |
| if (qatomic_cmpxchg(state, old_state, new_state) == old_state) { |
| return 0; |
| } else { |
| return -1; |
| } |
| } |
| |
| static struct DirtyRateInfo *query_dirty_rate_info(void) |
| { |
| int64_t dirty_rate = DirtyStat.dirty_rate; |
| struct DirtyRateInfo *info = g_malloc0(sizeof(DirtyRateInfo)); |
| |
| if (qatomic_read(&CalculatingState) == DIRTY_RATE_STATUS_MEASURED) { |
| info->has_dirty_rate = true; |
| info->dirty_rate = dirty_rate; |
| } |
| |
| info->status = CalculatingState; |
| info->start_time = DirtyStat.start_time; |
| info->calc_time = DirtyStat.calc_time; |
| |
| trace_query_dirty_rate_info(DirtyRateStatus_str(CalculatingState)); |
| |
| return info; |
| } |
| |
| static void init_dirtyrate_stat(int64_t start_time, int64_t calc_time) |
| { |
| DirtyStat.total_dirty_samples = 0; |
| DirtyStat.total_sample_count = 0; |
| DirtyStat.total_block_mem_MB = 0; |
| DirtyStat.dirty_rate = -1; |
| DirtyStat.start_time = start_time; |
| DirtyStat.calc_time = calc_time; |
| } |
| |
| static void update_dirtyrate_stat(struct RamblockDirtyInfo *info) |
| { |
| DirtyStat.total_dirty_samples += info->sample_dirty_count; |
| DirtyStat.total_sample_count += info->sample_pages_count; |
| /* size of total pages in MB */ |
| DirtyStat.total_block_mem_MB += (info->ramblock_pages * |
| TARGET_PAGE_SIZE) >> 20; |
| } |
| |
| static void update_dirtyrate(uint64_t msec) |
| { |
| uint64_t dirtyrate; |
| uint64_t total_dirty_samples = DirtyStat.total_dirty_samples; |
| uint64_t total_sample_count = DirtyStat.total_sample_count; |
| uint64_t total_block_mem_MB = DirtyStat.total_block_mem_MB; |
| |
| dirtyrate = total_dirty_samples * total_block_mem_MB * |
| 1000 / (total_sample_count * msec); |
| |
| DirtyStat.dirty_rate = dirtyrate; |
| } |
| |
| /* |
| * get hash result for the sampled memory with length of TARGET_PAGE_SIZE |
| * in ramblock, which starts from ramblock base address. |
| */ |
| static uint32_t get_ramblock_vfn_hash(struct RamblockDirtyInfo *info, |
| uint64_t vfn) |
| { |
| uint32_t crc; |
| |
| crc = crc32(0, (info->ramblock_addr + |
| vfn * TARGET_PAGE_SIZE), TARGET_PAGE_SIZE); |
| |
| trace_get_ramblock_vfn_hash(info->idstr, vfn, crc); |
| return crc; |
| } |
| |
| static bool save_ramblock_hash(struct RamblockDirtyInfo *info) |
| { |
| unsigned int sample_pages_count; |
| int i; |
| GRand *rand; |
| |
| sample_pages_count = info->sample_pages_count; |
| |
| /* ramblock size less than one page, return success to skip this ramblock */ |
| if (unlikely(info->ramblock_pages == 0 || sample_pages_count == 0)) { |
| return true; |
| } |
| |
| info->hash_result = g_try_malloc0_n(sample_pages_count, |
| sizeof(uint32_t)); |
| if (!info->hash_result) { |
| return false; |
| } |
| |
| info->sample_page_vfn = g_try_malloc0_n(sample_pages_count, |
| sizeof(uint64_t)); |
| if (!info->sample_page_vfn) { |
| g_free(info->hash_result); |
| return false; |
| } |
| |
| rand = g_rand_new(); |
| for (i = 0; i < sample_pages_count; i++) { |
| info->sample_page_vfn[i] = g_rand_int_range(rand, 0, |
| info->ramblock_pages - 1); |
| info->hash_result[i] = get_ramblock_vfn_hash(info, |
| info->sample_page_vfn[i]); |
| } |
| g_rand_free(rand); |
| |
| return true; |
| } |
| |
| static void get_ramblock_dirty_info(RAMBlock *block, |
| struct RamblockDirtyInfo *info, |
| struct DirtyRateConfig *config) |
| { |
| uint64_t sample_pages_per_gigabytes = config->sample_pages_per_gigabytes; |
| |
| /* Right shift 30 bits to calc ramblock size in GB */ |
| info->sample_pages_count = (qemu_ram_get_used_length(block) * |
| sample_pages_per_gigabytes) >> 30; |
| /* Right shift TARGET_PAGE_BITS to calc page count */ |
| info->ramblock_pages = qemu_ram_get_used_length(block) >> |
| TARGET_PAGE_BITS; |
| info->ramblock_addr = qemu_ram_get_host_addr(block); |
| strcpy(info->idstr, qemu_ram_get_idstr(block)); |
| } |
| |
| static void free_ramblock_dirty_info(struct RamblockDirtyInfo *infos, int count) |
| { |
| int i; |
| |
| if (!infos) { |
| return; |
| } |
| |
| for (i = 0; i < count; i++) { |
| g_free(infos[i].sample_page_vfn); |
| g_free(infos[i].hash_result); |
| } |
| g_free(infos); |
| } |
| |
| static bool skip_sample_ramblock(RAMBlock *block) |
| { |
| /* |
| * Sample only blocks larger than MIN_RAMBLOCK_SIZE. |
| */ |
| if (qemu_ram_get_used_length(block) < (MIN_RAMBLOCK_SIZE << 10)) { |
| trace_skip_sample_ramblock(block->idstr, |
| qemu_ram_get_used_length(block)); |
| return true; |
| } |
| |
| return false; |
| } |
| |
| static bool record_ramblock_hash_info(struct RamblockDirtyInfo **block_dinfo, |
| struct DirtyRateConfig config, |
| int *block_count) |
| { |
| struct RamblockDirtyInfo *info = NULL; |
| struct RamblockDirtyInfo *dinfo = NULL; |
| RAMBlock *block = NULL; |
| int total_count = 0; |
| int index = 0; |
| bool ret = false; |
| |
| RAMBLOCK_FOREACH_MIGRATABLE(block) { |
| if (skip_sample_ramblock(block)) { |
| continue; |
| } |
| total_count++; |
| } |
| |
| dinfo = g_try_malloc0_n(total_count, sizeof(struct RamblockDirtyInfo)); |
| if (dinfo == NULL) { |
| goto out; |
| } |
| |
| RAMBLOCK_FOREACH_MIGRATABLE(block) { |
| if (skip_sample_ramblock(block)) { |
| continue; |
| } |
| if (index >= total_count) { |
| break; |
| } |
| info = &dinfo[index]; |
| get_ramblock_dirty_info(block, info, &config); |
| if (!save_ramblock_hash(info)) { |
| goto out; |
| } |
| index++; |
| } |
| ret = true; |
| |
| out: |
| *block_count = index; |
| *block_dinfo = dinfo; |
| return ret; |
| } |
| |
| static void calc_page_dirty_rate(struct RamblockDirtyInfo *info) |
| { |
| uint32_t crc; |
| int i; |
| |
| for (i = 0; i < info->sample_pages_count; i++) { |
| crc = get_ramblock_vfn_hash(info, info->sample_page_vfn[i]); |
| if (crc != info->hash_result[i]) { |
| trace_calc_page_dirty_rate(info->idstr, crc, info->hash_result[i]); |
| info->sample_dirty_count++; |
| } |
| } |
| } |
| |
| static struct RamblockDirtyInfo * |
| find_block_matched(RAMBlock *block, int count, |
| struct RamblockDirtyInfo *infos) |
| { |
| int i; |
| struct RamblockDirtyInfo *matched; |
| |
| for (i = 0; i < count; i++) { |
| if (!strcmp(infos[i].idstr, qemu_ram_get_idstr(block))) { |
| break; |
| } |
| } |
| |
| if (i == count) { |
| return NULL; |
| } |
| |
| if (infos[i].ramblock_addr != qemu_ram_get_host_addr(block) || |
| infos[i].ramblock_pages != |
| (qemu_ram_get_used_length(block) >> TARGET_PAGE_BITS)) { |
| trace_find_page_matched(block->idstr); |
| return NULL; |
| } |
| |
| matched = &infos[i]; |
| |
| return matched; |
| } |
| |
| static bool compare_page_hash_info(struct RamblockDirtyInfo *info, |
| int block_count) |
| { |
| struct RamblockDirtyInfo *block_dinfo = NULL; |
| RAMBlock *block = NULL; |
| |
| RAMBLOCK_FOREACH_MIGRATABLE(block) { |
| if (skip_sample_ramblock(block)) { |
| continue; |
| } |
| block_dinfo = find_block_matched(block, block_count, info); |
| if (block_dinfo == NULL) { |
| continue; |
| } |
| calc_page_dirty_rate(block_dinfo); |
| update_dirtyrate_stat(block_dinfo); |
| } |
| |
| if (DirtyStat.total_sample_count == 0) { |
| return false; |
| } |
| |
| return true; |
| } |
| |
| static void calculate_dirtyrate(struct DirtyRateConfig config) |
| { |
| struct RamblockDirtyInfo *block_dinfo = NULL; |
| int block_count = 0; |
| int64_t msec = 0; |
| int64_t initial_time; |
| |
| rcu_register_thread(); |
| rcu_read_lock(); |
| initial_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); |
| if (!record_ramblock_hash_info(&block_dinfo, config, &block_count)) { |
| goto out; |
| } |
| rcu_read_unlock(); |
| |
| msec = config.sample_period_seconds * 1000; |
| msec = set_sample_page_period(msec, initial_time); |
| DirtyStat.start_time = initial_time / 1000; |
| DirtyStat.calc_time = msec / 1000; |
| |
| rcu_read_lock(); |
| if (!compare_page_hash_info(block_dinfo, block_count)) { |
| goto out; |
| } |
| |
| update_dirtyrate(msec); |
| |
| out: |
| rcu_read_unlock(); |
| free_ramblock_dirty_info(block_dinfo, block_count); |
| rcu_unregister_thread(); |
| } |
| |
| void *get_dirtyrate_thread(void *arg) |
| { |
| struct DirtyRateConfig config = *(struct DirtyRateConfig *)arg; |
| int ret; |
| int64_t start_time; |
| int64_t calc_time; |
| |
| ret = dirtyrate_set_state(&CalculatingState, DIRTY_RATE_STATUS_UNSTARTED, |
| DIRTY_RATE_STATUS_MEASURING); |
| if (ret == -1) { |
| error_report("change dirtyrate state failed."); |
| return NULL; |
| } |
| |
| start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME) / 1000; |
| calc_time = config.sample_period_seconds; |
| init_dirtyrate_stat(start_time, calc_time); |
| |
| calculate_dirtyrate(config); |
| |
| ret = dirtyrate_set_state(&CalculatingState, DIRTY_RATE_STATUS_MEASURING, |
| DIRTY_RATE_STATUS_MEASURED); |
| if (ret == -1) { |
| error_report("change dirtyrate state failed."); |
| } |
| return NULL; |
| } |
| |
| void qmp_calc_dirty_rate(int64_t calc_time, Error **errp) |
| { |
| static struct DirtyRateConfig config; |
| QemuThread thread; |
| int ret; |
| |
| /* |
| * If the dirty rate is already being measured, don't attempt to start. |
| */ |
| if (qatomic_read(&CalculatingState) == DIRTY_RATE_STATUS_MEASURING) { |
| error_setg(errp, "the dirty rate is already being measured."); |
| return; |
| } |
| |
| if (!is_sample_period_valid(calc_time)) { |
| error_setg(errp, "calc-time is out of range[%d, %d].", |
| MIN_FETCH_DIRTYRATE_TIME_SEC, |
| MAX_FETCH_DIRTYRATE_TIME_SEC); |
| return; |
| } |
| |
| /* |
| * Init calculation state as unstarted. |
| */ |
| ret = dirtyrate_set_state(&CalculatingState, CalculatingState, |
| DIRTY_RATE_STATUS_UNSTARTED); |
| if (ret == -1) { |
| error_setg(errp, "init dirty rate calculation state failed."); |
| return; |
| } |
| |
| config.sample_period_seconds = calc_time; |
| config.sample_pages_per_gigabytes = DIRTYRATE_DEFAULT_SAMPLE_PAGES; |
| qemu_thread_create(&thread, "get_dirtyrate", get_dirtyrate_thread, |
| (void *)&config, QEMU_THREAD_DETACHED); |
| } |
| |
| struct DirtyRateInfo *qmp_query_dirty_rate(Error **errp) |
| { |
| return query_dirty_rate_info(); |
| } |