5c6c3a6c54
Now that do have a nicer interface to work against we can add Linux native AIO support. It's an extremly thing layer just setting up an iocb for the io_submit system call in the submission path, and registering an eventfd with the qemu poll handler to do complete the iocbs directly from there. This started out based on Anthony's earlier AIO patch, but after estimated 42,000 rewrites and just as many build system changes there's not much left of it. To enable native kernel aio use the aio=native sub-command on the drive command line. I have also added an option to qemu-io to test the aio support without needing a guest. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
43 lines
1.3 KiB
C
43 lines
1.3 KiB
C
/*
|
|
* QEMU Posix block I/O backend AIO support
|
|
*
|
|
* 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.
|
|
*
|
|
*/
|
|
#ifndef QEMU_RAW_POSIX_AIO_H
|
|
#define QEMU_RAW_POSIX_AIO_H
|
|
|
|
/* AIO request types */
|
|
#define QEMU_AIO_READ 0x0001
|
|
#define QEMU_AIO_WRITE 0x0002
|
|
#define QEMU_AIO_IOCTL 0x0004
|
|
#define QEMU_AIO_TYPE_MASK \
|
|
(QEMU_AIO_READ|QEMU_AIO_WRITE|QEMU_AIO_IOCTL)
|
|
|
|
/* AIO flags */
|
|
#define QEMU_AIO_MISALIGNED 0x1000
|
|
|
|
|
|
/* posix-aio-compat.c - thread pool based implementation */
|
|
void *paio_init(void);
|
|
BlockDriverAIOCB *paio_submit(BlockDriverState *bs, void *aio_ctx, int fd,
|
|
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
|
|
BlockDriverCompletionFunc *cb, void *opaque, int type);
|
|
BlockDriverAIOCB *paio_ioctl(BlockDriverState *bs, int fd,
|
|
unsigned long int req, void *buf,
|
|
BlockDriverCompletionFunc *cb, void *opaque);
|
|
|
|
/* linux-aio.c - Linux native implementation */
|
|
void *laio_init(void);
|
|
BlockDriverAIOCB *laio_submit(BlockDriverState *bs, void *aio_ctx, int fd,
|
|
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
|
|
BlockDriverCompletionFunc *cb, void *opaque, int type);
|
|
|
|
#endif /* QEMU_RAW_POSIX_AIO_H */
|