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 "sysemu/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
  47 struct 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  */
  56 struct 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
  66 typedef 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  */
  75 struct 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
  86 void *get_dirtyrate_thread(void *arg);
  87 #endif