qemu/block_int.h
aliguori 221f715d90 new scsi-generic abstraction, use SG_IO (Christoph Hellwig)
Okay, I started looking into how to handle scsi-generic I/O in the
new world order.

I think the best is to use the SG_IO ioctl instead of the read/write
interface as that allows us to support scsi passthrough on disk/cdrom
devices, too.  See Hannes patch on the kvm list from August for an
example.

Now that we always do ioctls we don't need another abstraction than
bdrv_ioctl for the synchronous requests for now, and for asynchronous
requests I've added a aio_ioctl abstraction keeping it simple.

Long-term we might want to move the ops to a higher-level abstraction
and let the low-level code fill out the request header, but I'm lazy
enough to leave that to the people trying to support scsi-passthrough
on a non-Linux OS.

Tested lightly by issuing various sg_ commands from sg3-utils in a guest
to a host CDROM device.


Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6895 c046a42c-6fe2-441c-8c8c-71466251a162
2009-03-28 17:28:41 +00:00

164 lines
6.2 KiB
C

/*
* QEMU System Emulator block driver
*
* Copyright (c) 2003 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 BLOCK_INT_H
#define BLOCK_INT_H
#include "block.h"
#define BLOCK_FLAG_ENCRYPT 1
#define BLOCK_FLAG_COMPRESS 2
#define BLOCK_FLAG_COMPAT6 4
typedef struct AIOPool {
void (*cancel)(BlockDriverAIOCB *acb);
int aiocb_size;
BlockDriverAIOCB *free_aiocb;
} AIOPool;
struct BlockDriver {
const char *format_name;
int instance_size;
int (*bdrv_probe)(const uint8_t *buf, int buf_size, const char *filename);
int (*bdrv_open)(BlockDriverState *bs, const char *filename, int flags);
int (*bdrv_read)(BlockDriverState *bs, int64_t sector_num,
uint8_t *buf, int nb_sectors);
int (*bdrv_write)(BlockDriverState *bs, int64_t sector_num,
const uint8_t *buf, int nb_sectors);
void (*bdrv_close)(BlockDriverState *bs);
int (*bdrv_create)(const char *filename, int64_t total_sectors,
const char *backing_file, int flags);
void (*bdrv_flush)(BlockDriverState *bs);
int (*bdrv_is_allocated)(BlockDriverState *bs, int64_t sector_num,
int nb_sectors, int *pnum);
int (*bdrv_set_key)(BlockDriverState *bs, const char *key);
int (*bdrv_make_empty)(BlockDriverState *bs);
/* aio */
BlockDriverAIOCB *(*bdrv_aio_read)(BlockDriverState *bs,
int64_t sector_num, uint8_t *buf, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque);
BlockDriverAIOCB *(*bdrv_aio_write)(BlockDriverState *bs,
int64_t sector_num, const uint8_t *buf, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque);
void (*bdrv_aio_cancel)(BlockDriverAIOCB *acb);
int aiocb_size;
const char *protocol_name;
int (*bdrv_truncate)(BlockDriverState *bs, int64_t offset);
int64_t (*bdrv_getlength)(BlockDriverState *bs);
int (*bdrv_write_compressed)(BlockDriverState *bs, int64_t sector_num,
const uint8_t *buf, int nb_sectors);
int (*bdrv_snapshot_create)(BlockDriverState *bs,
QEMUSnapshotInfo *sn_info);
int (*bdrv_snapshot_goto)(BlockDriverState *bs,
const char *snapshot_id);
int (*bdrv_snapshot_delete)(BlockDriverState *bs, const char *snapshot_id);
int (*bdrv_snapshot_list)(BlockDriverState *bs,
QEMUSnapshotInfo **psn_info);
int (*bdrv_get_info)(BlockDriverState *bs, BlockDriverInfo *bdi);
/* removable device specific */
int (*bdrv_is_inserted)(BlockDriverState *bs);
int (*bdrv_media_changed)(BlockDriverState *bs);
int (*bdrv_eject)(BlockDriverState *bs, int eject_flag);
int (*bdrv_set_locked)(BlockDriverState *bs, int locked);
/* to control generic scsi devices */
int (*bdrv_ioctl)(BlockDriverState *bs, unsigned long int req, void *buf);
BlockDriverAIOCB *(*bdrv_aio_ioctl)(BlockDriverState *bs,
unsigned long int req, void *buf,
BlockDriverCompletionFunc *cb, void *opaque);
AIOPool aio_pool;
struct BlockDriver *next;
};
struct BlockDriverState {
int64_t total_sectors; /* if we are reading a disk image, give its
size in sectors */
int read_only; /* if true, the media is read only */
int removable; /* if true, the media can be removed */
int locked; /* if true, the media cannot temporarily be ejected */
int encrypted; /* if true, the media is encrypted */
int valid_key; /* if true, a valid encryption key has been set */
int sg; /* if true, the device is a /dev/sg* */
/* event callback when inserting/removing */
void (*change_cb)(void *opaque);
void *change_opaque;
BlockDriver *drv; /* NULL means no media */
void *opaque;
char filename[1024];
char backing_file[1024]; /* if non zero, the image is a diff of
this file image */
int is_temporary;
int media_changed;
BlockDriverState *backing_hd;
/* async read/write emulation */
void *sync_aiocb;
/* I/O stats (display with "info blockstats"). */
uint64_t rd_bytes;
uint64_t wr_bytes;
uint64_t rd_ops;
uint64_t wr_ops;
/* Whether the disk can expand beyond total_sectors */
int growable;
/* NOTE: the following infos are only hints for real hardware
drivers. They are not used by the block driver */
int cyls, heads, secs, translation;
int type;
char device_name[32];
BlockDriverState *next;
void *private;
};
struct BlockDriverAIOCB {
AIOPool *pool;
BlockDriverState *bs;
BlockDriverCompletionFunc *cb;
void *opaque;
BlockDriverAIOCB *next;
};
void get_tmp_filename(char *filename, int size);
void aio_pool_init(AIOPool *pool, int aiocb_size,
void (*cancel)(BlockDriverAIOCB *acb));
void *qemu_aio_get(BlockDriverState *bs, BlockDriverCompletionFunc *cb,
void *opaque);
void *qemu_aio_get_pool(AIOPool *pool, BlockDriverState *bs,
BlockDriverCompletionFunc *cb, void *opaque);
void qemu_aio_release(void *p);
extern BlockDriverState *bdrv_first;
#endif /* BLOCK_INT_H */