qemu/hw/scsi.h
Christoph Hellwig 428c149b0b block: add topology qdev properties
Add three new qdev properties to export block topology information to
the guest.  This is needed to get optimal I/O alignment for RAID arrays
or SSDs.

The options are:

 - physical_block_size to specify the physical block size of the device,
   this is going to increase from 512 bytes to 4096 kilobytes for many
   modern storage devices
 - min_io_size to specify the minimal I/O size without performance impact,
   this is typically set to the RAID chunk size for arrays.
 - opt_io_size to specify the optimal sustained I/O size, this is
   typically the RAID stripe width for arrays.

I decided to not auto-probe these values from blkid which might easily
be possible as I don't know how to deal with these issues on migration.

Note that we specificly only set the physical_block_size, and not the
logial one which is the unit all I/O is described in.  The reason for
that is that IDE does not support increasing the logical block size and
at last for now I want to stick to one meachnisms in queue and allow
for easy switching of transports for a given backing image which would
not be possible if scsi and virtio use real 4k sectors, while ide only
uses the physical block exponent.

To make this more common for the different block drivers introduce a
new BlockConf structure holding all common block properties and a
DEFINE_BLOCK_PROPERTIES macro to add them all together, mirroring
what is done for network drivers.  Also switch over all block drivers
to use it, except for the floppy driver which has weird driveA/driveB
properties and probably won't require any advanced block options ever.

Example usage for a virtio device with 4k physical block size and
8k optimal I/O size:

  -drive file=scratch.img,media=disk,cache=none,id=scratch \
  -device virtio-blk-pci,drive=scratch,physical_block_size=4096,opt_io_size=8192

aliguori: updated patch to take into account BLOCK events

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-02-10 16:53:25 -06:00

115 lines
3.1 KiB
C

#ifndef QEMU_HW_SCSI_H
#define QEMU_HW_SCSI_H
#include "qdev.h"
#include "block.h"
#include "block_int.h"
#define SCSI_CMD_BUF_SIZE 16
/* scsi-disk.c */
enum scsi_reason {
SCSI_REASON_DONE, /* Command complete. */
SCSI_REASON_DATA /* Transfer complete, more data required. */
};
typedef struct SCSIBus SCSIBus;
typedef struct SCSIDevice SCSIDevice;
typedef struct SCSIDeviceInfo SCSIDeviceInfo;
typedef void (*scsi_completionfn)(SCSIBus *bus, int reason, uint32_t tag,
uint32_t arg);
enum SCSIXferMode {
SCSI_XFER_NONE, /* TEST_UNIT_READY, ... */
SCSI_XFER_FROM_DEV, /* READ, INQUIRY, MODE_SENSE, ... */
SCSI_XFER_TO_DEV, /* WRITE, MODE_SELECT, ... */
};
typedef struct SCSISense {
uint8_t key;
} SCSISense;
typedef struct SCSIRequest {
SCSIBus *bus;
SCSIDevice *dev;
uint32_t tag;
uint32_t lun;
uint32_t status;
struct {
uint8_t buf[SCSI_CMD_BUF_SIZE];
int len;
size_t xfer;
uint64_t lba;
enum SCSIXferMode mode;
} cmd;
BlockDriverAIOCB *aiocb;
QTAILQ_ENTRY(SCSIRequest) next;
} SCSIRequest;
struct SCSIDevice
{
DeviceState qdev;
uint32_t id;
BlockConf conf;
SCSIDeviceInfo *info;
QTAILQ_HEAD(, SCSIRequest) requests;
int blocksize;
int type;
struct SCSISense sense;
};
/* cdrom.c */
int cdrom_read_toc(int nb_sectors, uint8_t *buf, int msf, int start_track);
int cdrom_read_toc_raw(int nb_sectors, uint8_t *buf, int msf, int session_num);
/* scsi-bus.c */
typedef int (*scsi_qdev_initfn)(SCSIDevice *dev);
struct SCSIDeviceInfo {
DeviceInfo qdev;
scsi_qdev_initfn init;
void (*destroy)(SCSIDevice *s);
int32_t (*send_command)(SCSIDevice *s, uint32_t tag, uint8_t *buf,
int lun);
void (*read_data)(SCSIDevice *s, uint32_t tag);
int (*write_data)(SCSIDevice *s, uint32_t tag);
void (*cancel_io)(SCSIDevice *s, uint32_t tag);
uint8_t *(*get_buf)(SCSIDevice *s, uint32_t tag);
};
typedef void (*SCSIAttachFn)(DeviceState *host, BlockDriverState *bdrv,
int unit);
struct SCSIBus {
BusState qbus;
int busnr;
int tcq, ndev;
scsi_completionfn complete;
SCSIDevice *devs[8];
};
void scsi_bus_new(SCSIBus *bus, DeviceState *host, int tcq, int ndev,
scsi_completionfn complete);
void scsi_qdev_register(SCSIDeviceInfo *info);
static inline SCSIBus *scsi_bus_from_device(SCSIDevice *d)
{
return DO_UPCAST(SCSIBus, qbus, d->qdev.parent_bus);
}
SCSIDevice *scsi_bus_legacy_add_drive(SCSIBus *bus, DriveInfo *dinfo, int unit);
void scsi_bus_legacy_handle_cmdline(SCSIBus *bus);
void scsi_dev_clear_sense(SCSIDevice *dev);
void scsi_dev_set_sense(SCSIDevice *dev, uint8_t key);
SCSIRequest *scsi_req_alloc(size_t size, SCSIDevice *d, uint32_t tag, uint32_t lun);
SCSIRequest *scsi_req_find(SCSIDevice *d, uint32_t tag);
void scsi_req_free(SCSIRequest *req);
int scsi_req_parse(SCSIRequest *req, uint8_t *buf);
void scsi_req_print(SCSIRequest *req);
void scsi_req_complete(SCSIRequest *req);
#endif