xref: /openbmc/qemu/migration/migration-stats.h (revision 542b10bd)
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      * Number of bytes transferred with QEMUFile.
86      */
87     Stat64 qemu_file_transferred;
88     /*
89      * Amount of transferred data at the start of current cycle.
90      */
91     Stat64 rate_limit_start;
92     /*
93      * Maximum amount of data we can send in a cycle.
94      */
95     Stat64 rate_limit_max;
96     /*
97      * Number of bytes sent through RDMA.
98      */
99     Stat64 rdma_bytes;
100     /*
101      * Number of pages transferred that were full of zeros.
102      */
103     Stat64 zero_pages;
104 } MigrationAtomicStats;
105 
106 extern MigrationAtomicStats mig_stats;
107 
108 /**
109  * migration_rate_get: Get the maximum amount that can be transferred.
110  *
111  * Returns the maximum number of bytes that can be transferred in a cycle.
112  */
113 uint64_t migration_rate_get(void);
114 
115 /**
116  * migration_rate_reset: Reset the rate limit counter.
117  *
118  * This is called when we know we start a new transfer cycle.
119  */
120 void migration_rate_reset(void);
121 
122 /**
123  * migration_rate_set: Set the maximum amount that can be transferred.
124  *
125  * Sets the maximum amount of bytes that can be transferred in one cycle.
126  *
127  * @new_rate: new maximum amount
128  */
129 void migration_rate_set(uint64_t new_rate);
130 
131 /**
132  * migration_transferred_bytes: Return number of bytes transferred
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(void);
139 #endif
140