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 /* Read a chunk of data from a file at the given position. The pos argument 29 * can be ignored if the file is only be used for streaming. The number of 30 * bytes actually read should be returned. 31 */ 32 typedef ssize_t (QEMUFileGetBufferFunc)(void *opaque, uint8_t *buf, 33 int64_t pos, size_t size); 34 35 /* Close a file 36 * 37 * Return negative error number on error, 0 or positive value on success. 38 * 39 * The meaning of return value on success depends on the specific back-end being 40 * used. 41 */ 42 typedef int (QEMUFileCloseFunc)(void *opaque); 43 44 /* Called to return the OS file descriptor associated to the QEMUFile. 45 */ 46 typedef int (QEMUFileGetFD)(void *opaque); 47 48 /* Called to change the blocking mode of the file 49 */ 50 typedef int (QEMUFileSetBlocking)(void *opaque, bool enabled); 51 52 /* 53 * This function writes an iovec to file. The handler must write all 54 * of the data or return a negative errno value. 55 */ 56 typedef ssize_t (QEMUFileWritevBufferFunc)(void *opaque, struct iovec *iov, 57 int iovcnt, int64_t pos); 58 59 /* 60 * This function provides hooks around different 61 * stages of RAM migration. 62 * 'opaque' is the backend specific data in QEMUFile 63 * 'data' is call specific data associated with the 'flags' value 64 */ 65 typedef int (QEMURamHookFunc)(QEMUFile *f, void *opaque, uint64_t flags, 66 void *data); 67 68 /* 69 * Constants used by ram_control_* hooks 70 */ 71 #define RAM_CONTROL_SETUP 0 72 #define RAM_CONTROL_ROUND 1 73 #define RAM_CONTROL_HOOK 2 74 #define RAM_CONTROL_FINISH 3 75 #define RAM_CONTROL_BLOCK_REG 4 76 77 /* 78 * This function allows override of where the RAM page 79 * is saved (such as RDMA, for example.) 80 */ 81 typedef size_t (QEMURamSaveFunc)(QEMUFile *f, void *opaque, 82 ram_addr_t block_offset, 83 ram_addr_t offset, 84 size_t size, 85 uint64_t *bytes_sent); 86 87 /* 88 * Return a QEMUFile for comms in the opposite direction 89 */ 90 typedef QEMUFile *(QEMURetPathFunc)(void *opaque); 91 92 /* 93 * Stop any read or write (depending on flags) on the underlying 94 * transport on the QEMUFile. 95 * Existing blocking reads/writes must be woken 96 * Returns 0 on success, -err on error 97 */ 98 typedef int (QEMUFileShutdownFunc)(void *opaque, bool rd, bool wr); 99 100 typedef struct QEMUFileOps { 101 QEMUFileGetBufferFunc *get_buffer; 102 QEMUFileCloseFunc *close; 103 QEMUFileSetBlocking *set_blocking; 104 QEMUFileWritevBufferFunc *writev_buffer; 105 QEMURetPathFunc *get_return_path; 106 QEMUFileShutdownFunc *shut_down; 107 } QEMUFileOps; 108 109 typedef struct QEMUFileHooks { 110 QEMURamHookFunc *before_ram_iterate; 111 QEMURamHookFunc *after_ram_iterate; 112 QEMURamHookFunc *hook_ram_load; 113 QEMURamSaveFunc *save_page; 114 } QEMUFileHooks; 115 116 QEMUFile *qemu_fopen_ops(void *opaque, const QEMUFileOps *ops); 117 void qemu_file_set_hooks(QEMUFile *f, const QEMUFileHooks *hooks); 118 int qemu_get_fd(QEMUFile *f); 119 int qemu_fclose(QEMUFile *f); 120 int64_t qemu_ftell(QEMUFile *f); 121 int64_t qemu_ftell_fast(QEMUFile *f); 122 /* 123 * put_buffer without copying the buffer. 124 * The buffer should be available till it is sent asynchronously. 125 */ 126 void qemu_put_buffer_async(QEMUFile *f, const uint8_t *buf, size_t size, 127 bool may_free); 128 bool qemu_file_mode_is_not_valid(const char *mode); 129 bool qemu_file_is_writable(QEMUFile *f); 130 131 #include "migration/qemu-file-types.h" 132 133 size_t qemu_peek_buffer(QEMUFile *f, uint8_t **buf, size_t size, size_t offset); 134 size_t qemu_get_buffer_in_place(QEMUFile *f, uint8_t **buf, size_t size); 135 ssize_t qemu_put_compression_data(QEMUFile *f, const uint8_t *p, size_t size, 136 int level); 137 int qemu_put_qemu_file(QEMUFile *f_des, QEMUFile *f_src); 138 139 /* 140 * Note that you can only peek continuous bytes from where the current pointer 141 * is; you aren't guaranteed to be able to peak to +n bytes unless you've 142 * previously peeked +n-1. 143 */ 144 int qemu_peek_byte(QEMUFile *f, int offset); 145 void qemu_file_skip(QEMUFile *f, int size); 146 void qemu_update_position(QEMUFile *f, size_t size); 147 void qemu_file_reset_rate_limit(QEMUFile *f); 148 void qemu_file_set_rate_limit(QEMUFile *f, int64_t new_rate); 149 int64_t qemu_file_get_rate_limit(QEMUFile *f); 150 int qemu_file_get_error(QEMUFile *f); 151 void qemu_file_set_error(QEMUFile *f, int ret); 152 int qemu_file_shutdown(QEMUFile *f); 153 QEMUFile *qemu_file_get_return_path(QEMUFile *f); 154 void qemu_fflush(QEMUFile *f); 155 void qemu_file_set_blocking(QEMUFile *f, bool block); 156 157 size_t qemu_get_counted_string(QEMUFile *f, char buf[256]); 158 159 void ram_control_before_iterate(QEMUFile *f, uint64_t flags); 160 void ram_control_after_iterate(QEMUFile *f, uint64_t flags); 161 void ram_control_load_hook(QEMUFile *f, uint64_t flags, void *data); 162 163 /* Whenever this is found in the data stream, the flags 164 * will be passed to ram_control_load_hook in the incoming-migration 165 * side. This lets before_ram_iterate/after_ram_iterate add 166 * transport-specific sections to the RAM migration data. 167 */ 168 #define RAM_SAVE_FLAG_HOOK 0x80 169 170 #define RAM_SAVE_CONTROL_NOT_SUPP -1000 171 #define RAM_SAVE_CONTROL_DELAYED -2000 172 173 size_t ram_control_save_page(QEMUFile *f, ram_addr_t block_offset, 174 ram_addr_t offset, size_t size, 175 uint64_t *bytes_sent); 176 177 #endif 178