qemu/migration/qemu-file.h
Peter Xu c6ad5be7ae migration: Teach QEMUFile to be QIOChannel-aware
migration uses QIOChannel typed qemufiles.  In follow up patches, we'll need
the capability to identify this fact, so that we can get the backing QIOChannel
from a QEMUFile.

We can also define types for QEMUFile but so far since we only need to be able
to identify QIOChannel, introduce a boolean which is simpler.

Introduce another helper qemu_file_get_ioc() to return the ioc backend of a
qemufile if has_ioc is set.

No functional change.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20210722175841.938739-5-peterx@redhat.com>
Reviewed-by: Lukas Straub <lukasstraub2@web.de>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2021-07-26 12:44:59 +01:00

186 lines
6.8 KiB
C

/*
* QEMU System Emulator
*
* Copyright (c) 2003-2008 Fabrice Bellard
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#ifndef MIGRATION_QEMU_FILE_H
#define MIGRATION_QEMU_FILE_H
#include <zlib.h>
#include "exec/cpu-common.h"
#include "io/channel.h"
/* Read a chunk of data from a file at the given position. The pos argument
* can be ignored if the file is only be used for streaming. The number of
* bytes actually read should be returned.
*/
typedef ssize_t (QEMUFileGetBufferFunc)(void *opaque, uint8_t *buf,
int64_t pos, size_t size,
Error **errp);
/* Close a file
*
* Return negative error number on error, 0 or positive value on success.
*
* The meaning of return value on success depends on the specific back-end being
* used.
*/
typedef int (QEMUFileCloseFunc)(void *opaque, Error **errp);
/* Called to return the OS file descriptor associated to the QEMUFile.
*/
typedef int (QEMUFileGetFD)(void *opaque);
/* Called to change the blocking mode of the file
*/
typedef int (QEMUFileSetBlocking)(void *opaque, bool enabled, Error **errp);
/*
* This function writes an iovec to file. The handler must write all
* of the data or return a negative errno value.
*/
typedef ssize_t (QEMUFileWritevBufferFunc)(void *opaque, struct iovec *iov,
int iovcnt, int64_t pos,
Error **errp);
/*
* This function provides hooks around different
* stages of RAM migration.
* 'opaque' is the backend specific data in QEMUFile
* 'data' is call specific data associated with the 'flags' value
*/
typedef int (QEMURamHookFunc)(QEMUFile *f, void *opaque, uint64_t flags,
void *data);
/*
* Constants used by ram_control_* hooks
*/
#define RAM_CONTROL_SETUP 0
#define RAM_CONTROL_ROUND 1
#define RAM_CONTROL_HOOK 2
#define RAM_CONTROL_FINISH 3
#define RAM_CONTROL_BLOCK_REG 4
/*
* This function allows override of where the RAM page
* is saved (such as RDMA, for example.)
*/
typedef size_t (QEMURamSaveFunc)(QEMUFile *f, void *opaque,
ram_addr_t block_offset,
ram_addr_t offset,
size_t size,
uint64_t *bytes_sent);
/*
* Return a QEMUFile for comms in the opposite direction
*/
typedef QEMUFile *(QEMURetPathFunc)(void *opaque);
/*
* Stop any read or write (depending on flags) on the underlying
* transport on the QEMUFile.
* Existing blocking reads/writes must be woken
* Returns 0 on success, -err on error
*/
typedef int (QEMUFileShutdownFunc)(void *opaque, bool rd, bool wr,
Error **errp);
typedef struct QEMUFileOps {
QEMUFileGetBufferFunc *get_buffer;
QEMUFileCloseFunc *close;
QEMUFileSetBlocking *set_blocking;
QEMUFileWritevBufferFunc *writev_buffer;
QEMURetPathFunc *get_return_path;
QEMUFileShutdownFunc *shut_down;
} QEMUFileOps;
typedef struct QEMUFileHooks {
QEMURamHookFunc *before_ram_iterate;
QEMURamHookFunc *after_ram_iterate;
QEMURamHookFunc *hook_ram_load;
QEMURamSaveFunc *save_page;
} QEMUFileHooks;
QEMUFile *qemu_fopen_ops(void *opaque, const QEMUFileOps *ops, bool has_ioc);
void qemu_file_set_hooks(QEMUFile *f, const QEMUFileHooks *hooks);
int qemu_get_fd(QEMUFile *f);
int qemu_fclose(QEMUFile *f);
int64_t qemu_ftell(QEMUFile *f);
int64_t qemu_ftell_fast(QEMUFile *f);
/*
* put_buffer without copying the buffer.
* The buffer should be available till it is sent asynchronously.
*/
void qemu_put_buffer_async(QEMUFile *f, const uint8_t *buf, size_t size,
bool may_free);
bool qemu_file_mode_is_not_valid(const char *mode);
bool qemu_file_is_writable(QEMUFile *f);
#include "migration/qemu-file-types.h"
size_t qemu_peek_buffer(QEMUFile *f, uint8_t **buf, size_t size, size_t offset);
size_t qemu_get_buffer_in_place(QEMUFile *f, uint8_t **buf, size_t size);
ssize_t qemu_put_compression_data(QEMUFile *f, z_stream *stream,
const uint8_t *p, size_t size);
int qemu_put_qemu_file(QEMUFile *f_des, QEMUFile *f_src);
/*
* Note that you can only peek continuous bytes from where the current pointer
* is; you aren't guaranteed to be able to peak to +n bytes unless you've
* previously peeked +n-1.
*/
int qemu_peek_byte(QEMUFile *f, int offset);
void qemu_file_skip(QEMUFile *f, int size);
void qemu_update_position(QEMUFile *f, size_t size);
void qemu_file_reset_rate_limit(QEMUFile *f);
void qemu_file_update_transfer(QEMUFile *f, int64_t len);
void qemu_file_set_rate_limit(QEMUFile *f, int64_t new_rate);
int64_t qemu_file_get_rate_limit(QEMUFile *f);
int qemu_file_get_error_obj(QEMUFile *f, Error **errp);
void qemu_file_set_error_obj(QEMUFile *f, int ret, Error *err);
void qemu_file_set_error(QEMUFile *f, int ret);
int qemu_file_shutdown(QEMUFile *f);
QEMUFile *qemu_file_get_return_path(QEMUFile *f);
void qemu_fflush(QEMUFile *f);
void qemu_file_set_blocking(QEMUFile *f, bool block);
void ram_control_before_iterate(QEMUFile *f, uint64_t flags);
void ram_control_after_iterate(QEMUFile *f, uint64_t flags);
void ram_control_load_hook(QEMUFile *f, uint64_t flags, void *data);
/* Whenever this is found in the data stream, the flags
* will be passed to ram_control_load_hook in the incoming-migration
* side. This lets before_ram_iterate/after_ram_iterate add
* transport-specific sections to the RAM migration data.
*/
#define RAM_SAVE_FLAG_HOOK 0x80
#define RAM_SAVE_CONTROL_NOT_SUPP -1000
#define RAM_SAVE_CONTROL_DELAYED -2000
size_t ram_control_save_page(QEMUFile *f, ram_addr_t block_offset,
ram_addr_t offset, size_t size,
uint64_t *bytes_sent);
QIOChannel *qemu_file_get_ioc(QEMUFile *file);
#endif