Merge tag 'linux-user-for-7.1-pull-request' of https://gitlab.com/laurent_vivier...
[qemu.git] / migration / qemu-file.h
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 /* Read a chunk of data from a file at the given position. The pos argument
33 * can be ignored if the file is only be used for streaming. The number of
34 * bytes actually read should be returned.
35 */
36 typedef ssize_t (QEMUFileGetBufferFunc)(void *opaque, uint8_t *buf,
37 int64_t pos, size_t size,
38 Error **errp);
39
40 /* Close a file
41 *
42 * Return negative error number on error, 0 or positive value on success.
43 *
44 * The meaning of return value on success depends on the specific back-end being
45 * used.
46 */
47 typedef int (QEMUFileCloseFunc)(void *opaque, Error **errp);
48
49 /* Called to return the OS file descriptor associated to the QEMUFile.
50 */
51 typedef int (QEMUFileGetFD)(void *opaque);
52
53 /* Called to change the blocking mode of the file
54 */
55 typedef int (QEMUFileSetBlocking)(void *opaque, bool enabled, Error **errp);
56
57 /*
58 * This function writes an iovec to file. The handler must write all
59 * of the data or return a negative errno value.
60 */
61 typedef ssize_t (QEMUFileWritevBufferFunc)(void *opaque, struct iovec *iov,
62 int iovcnt, int64_t pos,
63 Error **errp);
64
65 /*
66 * This function provides hooks around different
67 * stages of RAM migration.
68 * 'opaque' is the backend specific data in QEMUFile
69 * 'data' is call specific data associated with the 'flags' value
70 */
71 typedef int (QEMURamHookFunc)(QEMUFile *f, void *opaque, uint64_t flags,
72 void *data);
73
74 /*
75 * Constants used by ram_control_* hooks
76 */
77 #define RAM_CONTROL_SETUP 0
78 #define RAM_CONTROL_ROUND 1
79 #define RAM_CONTROL_HOOK 2
80 #define RAM_CONTROL_FINISH 3
81 #define RAM_CONTROL_BLOCK_REG 4
82
83 /*
84 * This function allows override of where the RAM page
85 * is saved (such as RDMA, for example.)
86 */
87 typedef size_t (QEMURamSaveFunc)(QEMUFile *f, void *opaque,
88 ram_addr_t block_offset,
89 ram_addr_t offset,
90 size_t size,
91 uint64_t *bytes_sent);
92
93 /*
94 * Return a QEMUFile for comms in the opposite direction
95 */
96 typedef QEMUFile *(QEMURetPathFunc)(void *opaque);
97
98 /*
99 * Stop any read or write (depending on flags) on the underlying
100 * transport on the QEMUFile.
101 * Existing blocking reads/writes must be woken
102 * Returns 0 on success, -err on error
103 */
104 typedef int (QEMUFileShutdownFunc)(void *opaque, bool rd, bool wr,
105 Error **errp);
106
107 typedef struct QEMUFileOps {
108 QEMUFileGetBufferFunc *get_buffer;
109 QEMUFileCloseFunc *close;
110 QEMUFileSetBlocking *set_blocking;
111 QEMUFileWritevBufferFunc *writev_buffer;
112 QEMURetPathFunc *get_return_path;
113 QEMUFileShutdownFunc *shut_down;
114 } QEMUFileOps;
115
116 typedef struct QEMUFileHooks {
117 QEMURamHookFunc *before_ram_iterate;
118 QEMURamHookFunc *after_ram_iterate;
119 QEMURamHookFunc *hook_ram_load;
120 QEMURamSaveFunc *save_page;
121 } QEMUFileHooks;
122
123 QEMUFile *qemu_fopen_ops(void *opaque, const QEMUFileOps *ops, bool has_ioc);
124 void qemu_file_set_hooks(QEMUFile *f, const QEMUFileHooks *hooks);
125 int qemu_get_fd(QEMUFile *f);
126 int qemu_fclose(QEMUFile *f);
127 int64_t qemu_ftell(QEMUFile *f);
128 int64_t qemu_ftell_fast(QEMUFile *f);
129 /*
130 * put_buffer without copying the buffer.
131 * The buffer should be available till it is sent asynchronously.
132 */
133 void qemu_put_buffer_async(QEMUFile *f, const uint8_t *buf, size_t size,
134 bool may_free);
135 bool qemu_file_mode_is_not_valid(const char *mode);
136 bool qemu_file_is_writable(QEMUFile *f);
137
138 #include "migration/qemu-file-types.h"
139
140 size_t qemu_peek_buffer(QEMUFile *f, uint8_t **buf, size_t size, size_t offset);
141 size_t qemu_get_buffer_in_place(QEMUFile *f, uint8_t **buf, size_t size);
142 ssize_t qemu_put_compression_data(QEMUFile *f, z_stream *stream,
143 const uint8_t *p, size_t size);
144 int qemu_put_qemu_file(QEMUFile *f_des, QEMUFile *f_src);
145
146 /*
147 * Note that you can only peek continuous bytes from where the current pointer
148 * is; you aren't guaranteed to be able to peak to +n bytes unless you've
149 * previously peeked +n-1.
150 */
151 int qemu_peek_byte(QEMUFile *f, int offset);
152 void qemu_file_skip(QEMUFile *f, int size);
153 void qemu_update_position(QEMUFile *f, size_t size);
154 void qemu_file_reset_rate_limit(QEMUFile *f);
155 void qemu_file_update_transfer(QEMUFile *f, int64_t len);
156 void qemu_file_set_rate_limit(QEMUFile *f, int64_t new_rate);
157 int64_t qemu_file_get_rate_limit(QEMUFile *f);
158 int qemu_file_get_error_obj(QEMUFile *f, Error **errp);
159 void qemu_file_set_error_obj(QEMUFile *f, int ret, Error *err);
160 void qemu_file_set_error(QEMUFile *f, int ret);
161 int qemu_file_shutdown(QEMUFile *f);
162 QEMUFile *qemu_file_get_return_path(QEMUFile *f);
163 void qemu_fflush(QEMUFile *f);
164 void qemu_file_set_blocking(QEMUFile *f, bool block);
165
166 void ram_control_before_iterate(QEMUFile *f, uint64_t flags);
167 void ram_control_after_iterate(QEMUFile *f, uint64_t flags);
168 void ram_control_load_hook(QEMUFile *f, uint64_t flags, void *data);
169
170 /* Whenever this is found in the data stream, the flags
171 * will be passed to ram_control_load_hook in the incoming-migration
172 * side. This lets before_ram_iterate/after_ram_iterate add
173 * transport-specific sections to the RAM migration data.
174 */
175 #define RAM_SAVE_FLAG_HOOK 0x80
176
177 #define RAM_SAVE_CONTROL_NOT_SUPP -1000
178 #define RAM_SAVE_CONTROL_DELAYED -2000
179
180 size_t ram_control_save_page(QEMUFile *f, ram_addr_t block_offset,
181 ram_addr_t offset, size_t size,
182 uint64_t *bytes_sent);
183 QIOChannel *qemu_file_get_ioc(QEMUFile *file);
184
185 #endif