qemu/include/hw/virtio/virtio-blk.h
Stefan Hajnoczi f897bf751f virtio-blk: embed VirtQueueElement in VirtIOBlockReq
The memory allocation between hw/block/virtio-blk.c,
hw/block/dataplane/virtio-blk.c, and hw/virtio/dataplane/vring.c is
messy.  Structs are allocated in different files than they are freed in.
This is risky and makes memory leaks easier.

Embed VirtQueueElement in VirtIOBlockReq to reduce the amount of memory
allocation we need to juggle.  This also makes vring.c and virtio.c
slightly more similar.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-07-14 12:03:20 +02:00

167 lines
4.3 KiB
C

/*
* Virtio Block Device
*
* Copyright IBM, Corp. 2007
*
* 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_VIRTIO_BLK_H
#define _QEMU_VIRTIO_BLK_H
#include "hw/virtio/virtio.h"
#include "hw/block/block.h"
#include "sysemu/iothread.h"
#include "block/block.h"
#define TYPE_VIRTIO_BLK "virtio-blk-device"
#define VIRTIO_BLK(obj) \
OBJECT_CHECK(VirtIOBlock, (obj), TYPE_VIRTIO_BLK)
/* from Linux's linux/virtio_blk.h */
/* The ID for virtio_block */
#define VIRTIO_ID_BLOCK 2
/* Feature bits */
#define VIRTIO_BLK_F_BARRIER 0 /* Does host support barriers? */
#define VIRTIO_BLK_F_SIZE_MAX 1 /* Indicates maximum segment size */
#define VIRTIO_BLK_F_SEG_MAX 2 /* Indicates maximum # of segments */
#define VIRTIO_BLK_F_GEOMETRY 4 /* Indicates support of legacy geometry */
#define VIRTIO_BLK_F_RO 5 /* Disk is read-only */
#define VIRTIO_BLK_F_BLK_SIZE 6 /* Block size of disk is available*/
#define VIRTIO_BLK_F_SCSI 7 /* Supports scsi command passthru */
/* #define VIRTIO_BLK_F_IDENTIFY 8 ATA IDENTIFY supported, DEPRECATED */
#define VIRTIO_BLK_F_WCE 9 /* write cache enabled */
#define VIRTIO_BLK_F_TOPOLOGY 10 /* Topology information is available */
#define VIRTIO_BLK_F_CONFIG_WCE 11 /* write cache configurable */
#define VIRTIO_BLK_ID_BYTES 20 /* ID string length */
struct virtio_blk_config
{
uint64_t capacity;
uint32_t size_max;
uint32_t seg_max;
uint16_t cylinders;
uint8_t heads;
uint8_t sectors;
uint32_t blk_size;
uint8_t physical_block_exp;
uint8_t alignment_offset;
uint16_t min_io_size;
uint32_t opt_io_size;
uint8_t wce;
} QEMU_PACKED;
/* These two define direction. */
#define VIRTIO_BLK_T_IN 0
#define VIRTIO_BLK_T_OUT 1
/* This bit says it's a scsi command, not an actual read or write. */
#define VIRTIO_BLK_T_SCSI_CMD 2
/* Flush the volatile write cache */
#define VIRTIO_BLK_T_FLUSH 4
/* return the device ID string */
#define VIRTIO_BLK_T_GET_ID 8
/* Barrier before this op. */
#define VIRTIO_BLK_T_BARRIER 0x80000000
/* This is the first element of the read scatter-gather list. */
struct virtio_blk_outhdr
{
/* VIRTIO_BLK_T* */
uint32_t type;
/* io priority. */
uint32_t ioprio;
/* Sector (ie. 512 byte offset) */
uint64_t sector;
};
#define VIRTIO_BLK_S_OK 0
#define VIRTIO_BLK_S_IOERR 1
#define VIRTIO_BLK_S_UNSUPP 2
/* This is the last element of the write scatter-gather list */
struct virtio_blk_inhdr
{
unsigned char status;
};
/* SCSI pass-through header */
struct virtio_scsi_inhdr
{
uint32_t errors;
uint32_t data_len;
uint32_t sense_len;
uint32_t residual;
};
struct VirtIOBlkConf
{
BlockConf conf;
IOThread *iothread;
char *serial;
uint32_t scsi;
uint32_t config_wce;
uint32_t data_plane;
};
struct VirtIOBlockDataPlane;
struct VirtIOBlockReq;
typedef struct VirtIOBlock {
VirtIODevice parent_obj;
BlockDriverState *bs;
VirtQueue *vq;
void *rq;
QEMUBH *bh;
BlockConf *conf;
VirtIOBlkConf blk;
unsigned short sector_mask;
bool original_wce;
VMChangeStateEntry *change;
/* Function to push to vq and notify guest */
void (*complete_request)(struct VirtIOBlockReq *req, unsigned char status);
#ifdef CONFIG_VIRTIO_BLK_DATA_PLANE
Notifier migration_state_notifier;
struct VirtIOBlockDataPlane *dataplane;
#endif
} VirtIOBlock;
typedef struct MultiReqBuffer {
BlockRequest blkreq[32];
unsigned int num_writes;
} MultiReqBuffer;
typedef struct VirtIOBlockReq {
VirtIOBlock *dev;
VirtQueueElement elem;
struct virtio_blk_inhdr *in;
struct virtio_blk_outhdr out;
QEMUIOVector qiov;
struct VirtIOBlockReq *next;
BlockAcctCookie acct;
} VirtIOBlockReq;
VirtIOBlockReq *virtio_blk_alloc_request(VirtIOBlock *s);
void virtio_blk_free_request(VirtIOBlockReq *req);
int virtio_blk_handle_scsi_req(VirtIOBlock *blk,
VirtQueueElement *elem);
void virtio_blk_handle_request(VirtIOBlockReq *req, MultiReqBuffer *mrb);
void virtio_submit_multiwrite(BlockDriverState *bs, MultiReqBuffer *mrb);
#endif