1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
|
/*
* Postcopy migration for RAM
*
* Copyright 2013 Red Hat, Inc. and/or its affiliates
*
* Authors:
* Dave Gilbert <dgilbert@redhat.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.
*
*/
#ifndef QEMU_POSTCOPY_RAM_H
#define QEMU_POSTCOPY_RAM_H
/* Return true if the host supports everything we need to do postcopy-ram */
bool postcopy_ram_supported_by_host(MigrationIncomingState *mis);
/*
* Make all of RAM sensitive to accesses to areas that haven't yet been written
* and wire up anything necessary to deal with it.
*/
int postcopy_ram_enable_notify(MigrationIncomingState *mis);
/*
* Initialise postcopy-ram, setting the RAM to a state where we can go into
* postcopy later; must be called prior to any precopy.
* called from ram.c's similarly named ram_postcopy_incoming_init
*/
int postcopy_ram_incoming_init(MigrationIncomingState *mis, size_t ram_pages);
/*
* At the end of a migration where postcopy_ram_incoming_init was called.
*/
int postcopy_ram_incoming_cleanup(MigrationIncomingState *mis);
/*
* Userfault requires us to mark RAM as NOHUGEPAGE prior to discard
* however leaving it until after precopy means that most of the precopy
* data is still THPd
*/
int postcopy_ram_prepare_discard(MigrationIncomingState *mis);
/*
* Called at the start of each RAMBlock by the bitmap code.
* Returns a new PDS
*/
PostcopyDiscardState *postcopy_discard_send_init(MigrationState *ms,
const char *name);
/*
* Called by the bitmap code for each chunk to discard.
* May send a discard message, may just leave it queued to
* be sent later.
* @start,@length: a range of pages in the migration bitmap in the
* RAM block passed to postcopy_discard_send_init() (length=1 is one page)
*/
void postcopy_discard_send_range(MigrationState *ms, PostcopyDiscardState *pds,
unsigned long start, unsigned long length);
/*
* Called at the end of each RAMBlock by the bitmap code.
* Sends any outstanding discard messages, frees the PDS.
*/
void postcopy_discard_send_finish(MigrationState *ms,
PostcopyDiscardState *pds);
/*
* Place a page (from) at (host) efficiently
* There are restrictions on how 'from' must be mapped, in general best
* to use other postcopy_ routines to allocate.
* returns 0 on success
*/
int postcopy_place_page(MigrationIncomingState *mis, void *host, void *from,
RAMBlock *rb);
/*
* Place a zero page at (host) atomically
* returns 0 on success
*/
int postcopy_place_page_zero(MigrationIncomingState *mis, void *host,
RAMBlock *rb);
/* The current postcopy state is read/set by postcopy_state_get/set
* which update it atomically.
* The state is updated as postcopy messages are received, and
* in general only one thread should be writing to the state at any one
* time, initially the main thread and then the listen thread;
* Corner cases are where either thread finishes early and/or errors.
* The state is checked as messages are received to ensure that
* the source is sending us messages in the correct order.
* The state is also used by the RAM reception code to know if it
* has to place pages atomically, and the cleanup code at the end of
* the main thread to know if it has to delay cleanup until the end
* of postcopy.
*/
typedef enum {
POSTCOPY_INCOMING_NONE = 0, /* Initial state - no postcopy */
POSTCOPY_INCOMING_ADVISE,
POSTCOPY_INCOMING_DISCARD,
POSTCOPY_INCOMING_LISTENING,
POSTCOPY_INCOMING_RUNNING,
POSTCOPY_INCOMING_END
} PostcopyState;
/*
* Allocate a page of memory that can be mapped at a later point in time
* using postcopy_place_page
* Returns: Pointer to allocated page
*/
void *postcopy_get_tmp_page(MigrationIncomingState *mis);
PostcopyState postcopy_state_get(void);
/* Set the state and return the old state */
PostcopyState postcopy_state_set(PostcopyState new_state);
void postcopy_fault_thread_notify(MigrationIncomingState *mis);
/*
* To be called once at the start before any device initialisation
*/
void postcopy_infrastructure_init(void);
/* Add a notifier to a list to be called when checking whether the devices
* can support postcopy.
* It's data is a *PostcopyNotifyData
* It should return 0 if OK, or a negative value on failure.
* On failure it must set the data->errp to an error.
*
*/
enum PostcopyNotifyReason {
POSTCOPY_NOTIFY_PROBE = 0,
POSTCOPY_NOTIFY_INBOUND_ADVISE,
};
struct PostcopyNotifyData {
enum PostcopyNotifyReason reason;
Error **errp;
};
void postcopy_add_notifier(NotifierWithReturn *nn);
void postcopy_remove_notifier(NotifierWithReturn *n);
/* Call the notifier list set by postcopy_add_start_notifier */
int postcopy_notify(enum PostcopyNotifyReason reason, Error **errp);
#endif
|
