1 /* 2 * Migration stats 3 * 4 * Copyright (c) 2012-2023 Red Hat Inc 5 * 6 * Authors: 7 * Juan Quintela <quintela@redhat.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_STATS_H 14 #define QEMU_MIGRATION_STATS_H 15 16 #include "qemu/stats64.h" 17 18 /* 19 * Amount of time to allocate to each "chunk" of bandwidth-throttled 20 * data. 21 */ 22 #define BUFFER_DELAY 100 23 24 /* 25 * If rate_limit_max is 0, there is special code to remove the rate 26 * limit. 27 */ 28 #define RATE_LIMIT_DISABLED 0 29 30 /* 31 * These are the ram migration statistic counters. It is loosely 32 * based on MigrationStats. We change to Stat64 any counter that 33 * needs to be updated using atomic ops (can be accessed by more than 34 * one thread). 35 */ 36 typedef struct { 37 /* 38 * Number of bytes that were dirty last time that we synced with 39 * the guest memory. We use that to calculate the downtime. As 40 * the remaining dirty amounts to what we know that is still dirty 41 * since last iteration, not counting what the guest has dirtied 42 * since we synchronized bitmaps. 43 */ 44 Stat64 dirty_bytes_last_sync; 45 /* 46 * Number of pages dirtied per second. 47 */ 48 Stat64 dirty_pages_rate; 49 /* 50 * Number of times we have synchronized guest bitmaps. 51 */ 52 Stat64 dirty_sync_count; 53 /* 54 * Number of times zero copy failed to send any page using zero 55 * copy. 56 */ 57 Stat64 dirty_sync_missed_zero_copy; 58 /* 59 * Number of bytes sent at migration completion stage while the 60 * guest is stopped. 61 */ 62 Stat64 downtime_bytes; 63 /* 64 * Number of bytes sent through multifd channels. 65 */ 66 Stat64 multifd_bytes; 67 /* 68 * Number of pages transferred that were not full of zeros. 69 */ 70 Stat64 normal_pages; 71 /* 72 * Number of bytes sent during postcopy. 73 */ 74 Stat64 postcopy_bytes; 75 /* 76 * Number of postcopy page faults that we have handled during 77 * postcopy stage. 78 */ 79 Stat64 postcopy_requests; 80 /* 81 * Number of bytes sent during precopy stage. 82 */ 83 Stat64 precopy_bytes; 84 /* 85 * Amount of transferred data at the start of current cycle. 86 */ 87 Stat64 rate_limit_start; 88 /* 89 * Maximum amount of data we can send in a cycle. 90 */ 91 Stat64 rate_limit_max; 92 /* 93 * Total number of bytes transferred. 94 */ 95 Stat64 transferred; 96 /* 97 * Number of pages transferred that were full of zeros. 98 */ 99 Stat64 zero_pages; 100 } MigrationAtomicStats; 101 102 extern MigrationAtomicStats mig_stats; 103 104 /** 105 * migration_rate_get: Get the maximum amount that can be transferred. 106 * 107 * Returns the maximum number of bytes that can be transferred in a cycle. 108 */ 109 uint64_t migration_rate_get(void); 110 111 /** 112 * migration_rate_reset: Reset the rate limit counter. 113 * 114 * This is called when we know we start a new transfer cycle. 115 * 116 * @f: QEMUFile used for main migration channel 117 */ 118 void migration_rate_reset(QEMUFile *f); 119 120 /** 121 * migration_rate_set: Set the maximum amount that can be transferred. 122 * 123 * Sets the maximum amount of bytes that can be transferred in one cycle. 124 * 125 * @new_rate: new maximum amount 126 */ 127 void migration_rate_set(uint64_t new_rate); 128 129 /** 130 * migration_transferred_bytes: Return number of bytes transferred 131 * 132 * @f: QEMUFile used for main migration channel 133 * 134 * Returns how many bytes have we transferred since the beginning of 135 * the migration. It accounts for bytes sent through any migration 136 * channel, multifd, qemu_file, rdma, .... 137 */ 138 uint64_t migration_transferred_bytes(QEMUFile *f); 139 #endif 140