qemu-file.h (6960B)
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 */ 36typedef 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 */ 47typedef int (QEMUFileCloseFunc)(void *opaque, Error **errp); 48 49/* Called to return the OS file descriptor associated to the QEMUFile. 50 */ 51typedef int (QEMUFileGetFD)(void *opaque); 52 53/* Called to change the blocking mode of the file 54 */ 55typedef 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 */ 61typedef 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 */ 71typedef 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 */ 87typedef 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 */ 96typedef 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 */ 104typedef int (QEMUFileShutdownFunc)(void *opaque, bool rd, bool wr, 105 Error **errp); 106 107typedef 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 116typedef struct QEMUFileHooks { 117 QEMURamHookFunc *before_ram_iterate; 118 QEMURamHookFunc *after_ram_iterate; 119 QEMURamHookFunc *hook_ram_load; 120 QEMURamSaveFunc *save_page; 121} QEMUFileHooks; 122 123QEMUFile *qemu_fopen_ops(void *opaque, const QEMUFileOps *ops, bool has_ioc); 124void qemu_file_set_hooks(QEMUFile *f, const QEMUFileHooks *hooks); 125int qemu_get_fd(QEMUFile *f); 126int qemu_fclose(QEMUFile *f); 127int64_t qemu_ftell(QEMUFile *f); 128int64_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 */ 133void qemu_put_buffer_async(QEMUFile *f, const uint8_t *buf, size_t size, 134 bool may_free); 135bool qemu_file_mode_is_not_valid(const char *mode); 136bool qemu_file_is_writable(QEMUFile *f); 137 138#include "migration/qemu-file-types.h" 139 140size_t qemu_peek_buffer(QEMUFile *f, uint8_t **buf, size_t size, size_t offset); 141size_t qemu_get_buffer_in_place(QEMUFile *f, uint8_t **buf, size_t size); 142ssize_t qemu_put_compression_data(QEMUFile *f, z_stream *stream, 143 const uint8_t *p, size_t size); 144int 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 */ 151int qemu_peek_byte(QEMUFile *f, int offset); 152void qemu_file_skip(QEMUFile *f, int size); 153void qemu_update_position(QEMUFile *f, size_t size); 154void qemu_file_reset_rate_limit(QEMUFile *f); 155void qemu_file_update_transfer(QEMUFile *f, int64_t len); 156void qemu_file_set_rate_limit(QEMUFile *f, int64_t new_rate); 157int64_t qemu_file_get_rate_limit(QEMUFile *f); 158int qemu_file_get_error_obj(QEMUFile *f, Error **errp); 159void qemu_file_set_error_obj(QEMUFile *f, int ret, Error *err); 160void qemu_file_set_error(QEMUFile *f, int ret); 161int qemu_file_shutdown(QEMUFile *f); 162QEMUFile *qemu_file_get_return_path(QEMUFile *f); 163void qemu_fflush(QEMUFile *f); 164void qemu_file_set_blocking(QEMUFile *f, bool block); 165 166void ram_control_before_iterate(QEMUFile *f, uint64_t flags); 167void ram_control_after_iterate(QEMUFile *f, uint64_t flags); 168void 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 180size_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); 183QIOChannel *qemu_file_get_ioc(QEMUFile *file); 184 185#endif