qemu/include/block/raw-aio.h
Prasad Pandit 24687abf23 linux-aio: add IO_CMD_FDSYNC command support
Libaio defines IO_CMD_FDSYNC command to sync all outstanding
asynchronous I/O operations, by flushing out file data to the
disk storage. Enable linux-aio to submit such aio request.

When using aio=native without fdsync() support, QEMU creates
pthreads, and destroying these pthreads results in TLB flushes.
In a real-time guest environment, TLB flushes cause a latency
spike. This patch helps to avoid such spikes.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Prasad Pandit <pjp@fedoraproject.org>
Message-ID: <20240425070412.37248-1-ppandit@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2024-06-10 11:05:43 +02:00

95 lines
3.2 KiB
C

/*
* Declarations for AIO in the raw protocol
*
* Copyright IBM, Corp. 2008
*
* Authors:
* Anthony Liguori <aliguori@us.ibm.com>
*
* This work is licensed under the terms of the GNU GPL, version 2. See
* the COPYING file in the top-level directory.
*
* Contributions after 2012-01-13 are licensed under the terms of the
* GNU GPL, version 2 or (at your option) any later version.
*/
#ifndef QEMU_RAW_AIO_H
#define QEMU_RAW_AIO_H
#include "block/aio.h"
#include "qemu/iov.h"
/* AIO request types */
#define QEMU_AIO_READ 0x0001
#define QEMU_AIO_WRITE 0x0002
#define QEMU_AIO_IOCTL 0x0004
#define QEMU_AIO_FLUSH 0x0008
#define QEMU_AIO_DISCARD 0x0010
#define QEMU_AIO_WRITE_ZEROES 0x0020
#define QEMU_AIO_COPY_RANGE 0x0040
#define QEMU_AIO_TRUNCATE 0x0080
#define QEMU_AIO_ZONE_REPORT 0x0100
#define QEMU_AIO_ZONE_MGMT 0x0200
#define QEMU_AIO_ZONE_APPEND 0x0400
#define QEMU_AIO_TYPE_MASK \
(QEMU_AIO_READ | \
QEMU_AIO_WRITE | \
QEMU_AIO_IOCTL | \
QEMU_AIO_FLUSH | \
QEMU_AIO_DISCARD | \
QEMU_AIO_WRITE_ZEROES | \
QEMU_AIO_COPY_RANGE | \
QEMU_AIO_TRUNCATE | \
QEMU_AIO_ZONE_REPORT | \
QEMU_AIO_ZONE_MGMT | \
QEMU_AIO_ZONE_APPEND)
/* AIO flags */
#define QEMU_AIO_MISALIGNED 0x1000
#define QEMU_AIO_BLKDEV 0x2000
#define QEMU_AIO_NO_FALLBACK 0x4000
/* linux-aio.c - Linux native implementation */
#ifdef CONFIG_LINUX_AIO
typedef struct LinuxAioState LinuxAioState;
LinuxAioState *laio_init(Error **errp);
void laio_cleanup(LinuxAioState *s);
/* laio_co_submit: submit I/O requests in the thread's current AioContext. */
int coroutine_fn laio_co_submit(int fd, uint64_t offset, QEMUIOVector *qiov,
int type, uint64_t dev_max_batch);
bool laio_has_fdsync(int);
void laio_detach_aio_context(LinuxAioState *s, AioContext *old_context);
void laio_attach_aio_context(LinuxAioState *s, AioContext *new_context);
#endif
/* io_uring.c - Linux io_uring implementation */
#ifdef CONFIG_LINUX_IO_URING
LuringState *luring_init(Error **errp);
void luring_cleanup(LuringState *s);
/* luring_co_submit: submit I/O requests in the thread's current AioContext. */
int coroutine_fn luring_co_submit(BlockDriverState *bs, int fd, uint64_t offset,
QEMUIOVector *qiov, int type);
void luring_detach_aio_context(LuringState *s, AioContext *old_context);
void luring_attach_aio_context(LuringState *s, AioContext *new_context);
#endif
#ifdef _WIN32
typedef struct QEMUWin32AIOState QEMUWin32AIOState;
QEMUWin32AIOState *win32_aio_init(void);
void win32_aio_cleanup(QEMUWin32AIOState *aio);
int win32_aio_attach(QEMUWin32AIOState *aio, HANDLE hfile);
BlockAIOCB *win32_aio_submit(BlockDriverState *bs,
QEMUWin32AIOState *aio, HANDLE hfile,
uint64_t offset, uint64_t bytes, QEMUIOVector *qiov,
BlockCompletionFunc *cb, void *opaque, int type);
void win32_aio_detach_aio_context(QEMUWin32AIOState *aio,
AioContext *old_context);
void win32_aio_attach_aio_context(QEMUWin32AIOState *aio,
AioContext *new_context);
#endif
#endif /* QEMU_RAW_AIO_H */