xref: /qemu/migration/qemu-file.h (revision bb302772)
1 /*
2  * QEMU System Emulator
3  *
4  * Copyright (c) 2003-2008 Fabrice Bellard
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to deal
8  * in the Software without restriction, including without limitation the rights
9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10  * copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22  * THE SOFTWARE.
23  */
24 
25 #ifndef MIGRATION_QEMU_FILE_H
26 #define MIGRATION_QEMU_FILE_H
27 
28 #include <zlib.h>
29 #include "exec/cpu-common.h"
30 #include "io/channel.h"
31 
32 /*
33  * This function provides hooks around different
34  * stages of RAM migration.
35  * 'data' is call specific data associated with the 'flags' value
36  */
37 typedef int (QEMURamHookFunc)(QEMUFile *f, uint64_t flags, void *data);
38 
39 /*
40  * Constants used by ram_control_* hooks
41  */
42 #define RAM_CONTROL_SETUP     0
43 #define RAM_CONTROL_ROUND     1
44 #define RAM_CONTROL_HOOK      2
45 #define RAM_CONTROL_FINISH    3
46 #define RAM_CONTROL_BLOCK_REG 4
47 
48 /*
49  * This function allows override of where the RAM page
50  * is saved (such as RDMA, for example.)
51  */
52 typedef int (QEMURamSaveFunc)(QEMUFile *f,
53                               ram_addr_t block_offset,
54                               ram_addr_t offset,
55                               size_t size);
56 
57 typedef struct QEMUFileHooks {
58     QEMURamHookFunc *before_ram_iterate;
59     QEMURamHookFunc *after_ram_iterate;
60     QEMURamHookFunc *hook_ram_load;
61     QEMURamSaveFunc *save_page;
62 } QEMUFileHooks;
63 
64 QEMUFile *qemu_file_new_input(QIOChannel *ioc);
65 QEMUFile *qemu_file_new_output(QIOChannel *ioc);
66 void qemu_file_set_hooks(QEMUFile *f, const QEMUFileHooks *hooks);
67 int qemu_fclose(QEMUFile *f);
68 
69 /*
70  * qemu_file_transferred:
71  *
72  * Report the total number of bytes transferred with
73  * this file.
74  *
75  * For writable files, any pending buffers will be
76  * flushed, so the reported value will be equal to
77  * the number of bytes transferred on the wire.
78  *
79  * For readable files, the reported value will be
80  * equal to the number of bytes transferred on the
81  * wire.
82  *
83  * Returns: the total bytes transferred
84  */
85 uint64_t qemu_file_transferred(QEMUFile *f);
86 
87 /*
88  * qemu_file_transferred_noflush:
89  *
90  * As qemu_file_transferred except for writable files, where no flush
91  * is performed and the reported amount will include the size of any
92  * queued buffers, on top of the amount actually transferred.
93  *
94  * Returns: the total bytes transferred and queued
95  */
96 uint64_t qemu_file_transferred_noflush(QEMUFile *f);
97 
98 /*
99  * put_buffer without copying the buffer.
100  * The buffer should be available till it is sent asynchronously.
101  */
102 void qemu_put_buffer_async(QEMUFile *f, const uint8_t *buf, size_t size,
103                            bool may_free);
104 
105 #include "migration/qemu-file-types.h"
106 
107 size_t coroutine_mixed_fn qemu_peek_buffer(QEMUFile *f, uint8_t **buf, size_t size, size_t offset);
108 size_t coroutine_mixed_fn qemu_get_buffer_in_place(QEMUFile *f, uint8_t **buf, size_t size);
109 ssize_t qemu_put_compression_data(QEMUFile *f, z_stream *stream,
110                                   const uint8_t *p, size_t size);
111 int qemu_put_qemu_file(QEMUFile *f_des, QEMUFile *f_src);
112 bool qemu_file_buffer_empty(QEMUFile *file);
113 
114 /*
115  * Note that you can only peek continuous bytes from where the current pointer
116  * is; you aren't guaranteed to be able to peak to +n bytes unless you've
117  * previously peeked +n-1.
118  */
119 int coroutine_mixed_fn qemu_peek_byte(QEMUFile *f, int offset);
120 void qemu_file_skip(QEMUFile *f, int size);
121 int qemu_file_get_error_obj_any(QEMUFile *f1, QEMUFile *f2, Error **errp);
122 void qemu_file_set_error_obj(QEMUFile *f, int ret, Error *err);
123 void qemu_file_set_error(QEMUFile *f, int ret);
124 int qemu_file_shutdown(QEMUFile *f);
125 QEMUFile *qemu_file_get_return_path(QEMUFile *f);
126 void qemu_fflush(QEMUFile *f);
127 void qemu_file_set_blocking(QEMUFile *f, bool block);
128 int qemu_file_get_to_fd(QEMUFile *f, int fd, size_t size);
129 
130 void ram_control_before_iterate(QEMUFile *f, uint64_t flags);
131 void ram_control_after_iterate(QEMUFile *f, uint64_t flags);
132 void ram_control_load_hook(QEMUFile *f, uint64_t flags, void *data);
133 
134 /* Whenever this is found in the data stream, the flags
135  * will be passed to ram_control_load_hook in the incoming-migration
136  * side. This lets before_ram_iterate/after_ram_iterate add
137  * transport-specific sections to the RAM migration data.
138  */
139 #define RAM_SAVE_FLAG_HOOK     0x80
140 
141 #define RAM_SAVE_CONTROL_NOT_SUPP -1000
142 #define RAM_SAVE_CONTROL_DELAYED  -2000
143 
144 int ram_control_save_page(QEMUFile *f, ram_addr_t block_offset,
145                           ram_addr_t offset, size_t size);
146 QIOChannel *qemu_file_get_ioc(QEMUFile *file);
147 
148 #endif
149