LXR qemu/migration/dirtyrate.h

   1/*
   2 *  Dirtyrate common functions
   3 *
   4 *  Copyright (c) 2020 HUAWEI TECHNOLOGIES CO., LTD.
   5 *
   6 *  Authors:
   7 *  Chuan Zheng <zhengchuan@huawei.com>
   8 *
   9 *  This work is licensed under the terms of the GNU GPL, version 2 or later.
  10 *  See the COPYING file in the top-level directory.
  11 */
  12
  13#ifndef QEMU_MIGRATION_DIRTYRATE_H
  14#define QEMU_MIGRATION_DIRTYRATE_H
  15
  16#include "system/dirtyrate.h"
  17
  18/*
  19 * Sample 512 pages per GB as default.
  20 */
  21#define DIRTYRATE_DEFAULT_SAMPLE_PAGES            512
  22
  23/*
  24 * Record ramblock idstr
  25 */
  26#define RAMBLOCK_INFO_MAX_LEN                     256
  27
  28/*
  29 * Minimum RAMBlock size to sample, in megabytes.
  30 */
  31#define MIN_RAMBLOCK_SIZE                         128
  32
  33/*
  34 * Allowed range for dirty page rate calculation (in milliseconds).
  35 * Lower limit relates to the smallest realistic downtime it
  36 * makes sense to impose on migration.
  37 */
  38#define MIN_CALC_TIME_MS                          50
  39#define MAX_CALC_TIME_MS                       60000
  40
  41/*
  42 * Take 1/16 pages in 1G as the maxmum sample page count
  43 */
  44#define MIN_SAMPLE_PAGE_COUNT                     128
  45#define MAX_SAMPLE_PAGE_COUNT                     16384
  46
  47struct DirtyRateConfig {
  48    uint64_t sample_pages_per_gigabytes; /* sample pages per GB */
  49    int64_t calc_time_ms; /* desired calculation time (in milliseconds) */
  50    DirtyRateMeasureMode mode; /* mode of dirtyrate measurement */
  51};
  52
  53/*
  54 * Store dirtypage info for each ramblock.
  55 */
  56struct RamblockDirtyInfo {
  57    char idstr[RAMBLOCK_INFO_MAX_LEN]; /* idstr for each ramblock */
  58    uint8_t *ramblock_addr; /* base address of ramblock we measure */
  59    uint64_t ramblock_pages; /* ramblock size in TARGET_PAGE_SIZE */
  60    uint64_t *sample_page_vfn; /* relative offset address for sampled page */
  61    uint64_t sample_pages_count; /* count of sampled pages */
  62    uint64_t sample_dirty_count; /* count of dirty pages we measure */
  63    uint32_t *hash_result; /* array of hash result for sampled pages */
  64};
  65
  66typedef struct SampleVMStat {
  67    uint64_t total_dirty_samples; /* total dirty sampled page */
  68    uint64_t total_sample_count; /* total sampled pages */
  69    uint64_t total_block_mem_MB; /* size of total sampled pages in MB */
  70} SampleVMStat;
  71
  72/*
  73 * Store calculation statistics for each measure.
  74 */
  75struct DirtyRateStat {
  76    int64_t dirty_rate; /* dirty rate in MB/s */
  77    int64_t start_time; /* calculation start time in units of second */
  78    int64_t calc_time_ms; /* actual calculation time (in milliseconds) */
  79    uint64_t sample_pages; /* sample pages per GB */
  80    union {
  81        SampleVMStat page_sampling;
  82        VcpuStat dirty_ring;
  83    };
  84};
  85
  86void *get_dirtyrate_thread(void *arg);
  87#endif
  88