Merge remote-tracking branch 'remotes/dgilbert/tags/pull-migration-20200925a' into...
[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
31 /* Read a chunk of data from a file at the given position. The pos argument
32 * can be ignored if the file is only be used for streaming. The number of
33 * bytes actually read should be returned.
34 */
35 typedef ssize_t (QEMUFileGetBufferFunc)(void *opaque, uint8_t *buf,
36 int64_t pos, size_t size,
37 Error **errp);
38
39 /* Close a file
40 *
41 * Return negative error number on error, 0 or positive value on success.
42 *
43 * The meaning of return value on success depends on the specific back-end being
44 * used.
45 */
46 typedef int (QEMUFileCloseFunc)(void *opaque, Error **errp);
47
48 /* Called to return the OS file descriptor associated to the QEMUFile.
49 */
50 typedef int (QEMUFileGetFD)(void *opaque);
51
52 /* Called to change the blocking mode of the file
53 */
54 typedef int (QEMUFileSetBlocking)(void *opaque, bool enabled, Error **errp);
55
56 /*
57 * This function writes an iovec to file. The handler must write all
58 * of the data or return a negative errno value.
59 */
60 typedef ssize_t (QEMUFileWritevBufferFunc)(void *opaque, struct iovec *iov,
61 int iovcnt, int64_t pos,
62 Error **errp);
63
64 /*
65 * This function provides hooks around different
66 * stages of RAM migration.
67 * 'opaque' is the backend specific data in QEMUFile
68 * 'data' is call specific data associated with the 'flags' value
69 */
70 typedef int (QEMURamHookFunc)(QEMUFile *f, void *opaque, uint64_t flags,
71 void *data);
72
73 /*
74 * Constants used by ram_control_* hooks
75 */
76 #define RAM_CONTROL_SETUP 0
77 #define RAM_CONTROL_ROUND 1
78 #define RAM_CONTROL_HOOK 2
79 #define RAM_CONTROL_FINISH 3
80 #define RAM_CONTROL_BLOCK_REG 4
81
82 /*
83 * This function allows override of where the RAM page
84 * is saved (such as RDMA, for example.)
85 */
86 typedef size_t (QEMURamSaveFunc)(QEMUFile *f, void *opaque,
87 ram_addr_t block_offset,
88 ram_addr_t offset,
89 size_t size,
90 uint64_t *bytes_sent);
91
92 /*
93 * Return a QEMUFile for comms in the opposite direction
94 */
95 typedef QEMUFile *(QEMURetPathFunc)(void *opaque);
96
97 /*
98 * Stop any read or write (depending on flags) on the underlying
99 * transport on the QEMUFile.
100 * Existing blocking reads/writes must be woken
101 * Returns 0 on success, -err on error
102 */
103 typedef int (QEMUFileShutdownFunc)(void *opaque, bool rd, bool wr,
104 Error **errp);
105
106 typedef struct QEMUFileOps {
107 QEMUFileGetBufferFunc *get_buffer;
108 QEMUFileCloseFunc *close;
109 QEMUFileSetBlocking *set_blocking;
110 QEMUFileWritevBufferFunc *writev_buffer;
111 QEMURetPathFunc *get_return_path;
112 QEMUFileShutdownFunc *shut_down;
113 } QEMUFileOps;
114
115 typedef struct QEMUFileHooks {
116 QEMURamHookFunc *before_ram_iterate;
117 QEMURamHookFunc *after_ram_iterate;
118 QEMURamHookFunc *hook_ram_load;
119 QEMURamSaveFunc *save_page;
120 } QEMUFileHooks;
121
122 QEMUFile *qemu_fopen_ops(void *opaque, const QEMUFileOps *ops);
123 void qemu_file_set_hooks(QEMUFile *f, const QEMUFileHooks *hooks);
124 int qemu_get_fd(QEMUFile *f);
125 int qemu_fclose(QEMUFile *f);
126 int64_t qemu_ftell(QEMUFile *f);
127 int64_t qemu_ftell_fast(QEMUFile *f);
128 /*
129 * put_buffer without copying the buffer.
130 * The buffer should be available till it is sent asynchronously.
131 */
132 void qemu_put_buffer_async(QEMUFile *f, const uint8_t *buf, size_t size,
133 bool may_free);
134 bool qemu_file_mode_is_not_valid(const char *mode);
135 bool qemu_file_is_writable(QEMUFile *f);
136
137 #include "migration/qemu-file-types.h"
138
139 size_t qemu_peek_buffer(QEMUFile *f, uint8_t **buf, size_t size, size_t offset);
140 size_t qemu_get_buffer_in_place(QEMUFile *f, uint8_t **buf, size_t size);
141 ssize_t qemu_put_compression_data(QEMUFile *f, z_stream *stream,
142 const uint8_t *p, size_t size);
143 int qemu_put_qemu_file(QEMUFile *f_des, QEMUFile *f_src);
144
145 /*
146 * Note that you can only peek continuous bytes from where the current pointer
147 * is; you aren't guaranteed to be able to peak to +n bytes unless you've
148 * previously peeked +n-1.
149 */
150 int qemu_peek_byte(QEMUFile *f, int offset);
151 void qemu_file_skip(QEMUFile *f, int size);
152 void qemu_update_position(QEMUFile *f, size_t size);
153 void qemu_file_reset_rate_limit(QEMUFile *f);
154 void qemu_file_update_transfer(QEMUFile *f, int64_t len);
155 void qemu_file_set_rate_limit(QEMUFile *f, int64_t new_rate);
156 int64_t qemu_file_get_rate_limit(QEMUFile *f);
157 int qemu_file_get_error_obj(QEMUFile *f, Error **errp);
158 void qemu_file_set_error_obj(QEMUFile *f, int ret, Error *err);
159 void qemu_file_set_error(QEMUFile *f, int ret);
160 int qemu_file_shutdown(QEMUFile *f);
161 QEMUFile *qemu_file_get_return_path(QEMUFile *f);
162 void qemu_fflush(QEMUFile *f);
163 void qemu_file_set_blocking(QEMUFile *f, bool block);
164
165 void ram_control_before_iterate(QEMUFile *f, uint64_t flags);
166 void ram_control_after_iterate(QEMUFile *f, uint64_t flags);
167 void ram_control_load_hook(QEMUFile *f, uint64_t flags, void *data);
168
169 /* Whenever this is found in the data stream, the flags
170 * will be passed to ram_control_load_hook in the incoming-migration
171 * side. This lets before_ram_iterate/after_ram_iterate add
172 * transport-specific sections to the RAM migration data.
173 */
174 #define RAM_SAVE_FLAG_HOOK 0x80
175
176 #define RAM_SAVE_CONTROL_NOT_SUPP -1000
177 #define RAM_SAVE_CONTROL_DELAYED -2000
178
179 size_t ram_control_save_page(QEMUFile *f, ram_addr_t block_offset,
180 ram_addr_t offset, size_t size,
181 uint64_t *bytes_sent);
182
183 #endif