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scsi-disk: introduce dma_readv and dma_writev

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These are replacements for blk_aio_readv and blk_aio_writev that allow
customization of the data path.  They reuse the DMA helpers' DMAIOFunc
callback type, so that the same function can be used in either the
QEMUSGList or the bounce-buffered case.

This customization will be needed in the next patch to do zero-copy
SG_IO on scsi-block.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini 2016-05-10 10:13:00 +02:00
parent 993935f315
commit fcaafb1001
1 changed files with 52 additions and 15 deletions
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67
hw/scsi/scsi-disk.c
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@ -55,7 +55,18 @@ do { printf("scsi-disk: " fmt , ## __VA_ARGS__); } while (0)
#define TYPE_SCSI_DISK_BASE "scsi-disk-base"
typedef struct SCSIDiskState SCSIDiskState;
#define SCSI_DISK_BASE(obj) \
OBJECT_CHECK(SCSIDiskState, (obj), TYPE_SCSI_DISK_BASE)
#define SCSI_DISK_BASE_CLASS(klass) \
OBJECT_CLASS_CHECK(SCSIDiskClass, (klass), TYPE_SCSI_DISK_BASE)
#define SCSI_DISK_BASE_GET_CLASS(obj) \
OBJECT_GET_CLASS(SCSIDiskClass, (obj), TYPE_SCSI_DISK_BASE)
typedef struct SCSIDiskClass {
SCSIDeviceClass parent_class;
DMAIOFunc *dma_readv;
DMAIOFunc *dma_writev;
} SCSIDiskClass;
typedef struct SCSIDiskReq {
SCSIRequest req;
@ -73,7 +84,7 @@ typedef struct SCSIDiskReq {
#define SCSI_DISK_F_DPOFUA 1
#define SCSI_DISK_F_NO_REMOVABLE_DEVOPS 2
struct SCSIDiskState
typedef struct SCSIDiskState
{
SCSIDevice qdev;
uint32_t features;
@ -90,7 +101,7 @@ struct SCSIDiskState
char *product;
bool tray_open;
bool tray_locked;
};
} SCSIDiskState;
static int scsi_handle_rw_error(SCSIDiskReq *r, int error, bool acct_failed);
@ -317,6 +328,7 @@ done:
static void scsi_do_read(SCSIDiskReq *r, int ret)
{
SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, r->req.dev);
SCSIDiskClass *sdc = (SCSIDiskClass *) object_get_class(OBJECT(s));
assert (r->req.aiocb == NULL);
@ -337,16 +349,16 @@ static void scsi_do_read(SCSIDiskReq *r, int ret)
if (r->req.sg) {
dma_acct_start(s->qdev.conf.blk, &r->acct, r->req.sg, BLOCK_ACCT_READ);
r->req.resid -= r->req.sg->size;
r->req.aiocb = dma_blk_read(s->qdev.conf.blk, r->req.sg,
r->sector << BDRV_SECTOR_BITS,
scsi_dma_complete, r);
r->req.aiocb = dma_blk_io(blk_get_aio_context(s->qdev.conf.blk),
r->req.sg, r->sector << BDRV_SECTOR_BITS,
sdc->dma_readv, r, scsi_dma_complete, r,
DMA_DIRECTION_FROM_DEVICE);
} else {
scsi_init_iovec(r, SCSI_DMA_BUF_SIZE);
block_acct_start(blk_get_stats(s->qdev.conf.blk), &r->acct,
r->qiov.size, BLOCK_ACCT_READ);
r->req.aiocb = blk_aio_preadv(s->qdev.conf.blk,
r->sector << BDRV_SECTOR_BITS, &r->qiov,
0, scsi_read_complete, r);
r->req.aiocb = sdc->dma_readv(r->sector, &r->qiov,
scsi_read_complete, r, r);
}
done:
@ -506,6 +518,7 @@ static void scsi_write_data(SCSIRequest *req)
{
SCSIDiskReq *r = DO_UPCAST(SCSIDiskReq, req, req);
SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, r->req.dev);
SCSIDiskClass *sdc = (SCSIDiskClass *) object_get_class(OBJECT(s));
/* No data transfer may already be in progress */
assert(r->req.aiocb == NULL);
@ -542,15 +555,15 @@ static void scsi_write_data(SCSIRequest *req)
if (r->req.sg) {
dma_acct_start(s->qdev.conf.blk, &r->acct, r->req.sg, BLOCK_ACCT_WRITE);
r->req.resid -= r->req.sg->size;
r->req.aiocb = dma_blk_write(s->qdev.conf.blk, r->req.sg,
r->sector << BDRV_SECTOR_BITS,
scsi_dma_complete, r);
r->req.aiocb = dma_blk_io(blk_get_aio_context(s->qdev.conf.blk),
r->req.sg, r->sector << BDRV_SECTOR_BITS,
sdc->dma_writev, r, scsi_dma_complete, r,
DMA_DIRECTION_TO_DEVICE);
} else {
block_acct_start(blk_get_stats(s->qdev.conf.blk), &r->acct,
r->qiov.size, BLOCK_ACCT_WRITE);
r->req.aiocb = blk_aio_pwritev(s->qdev.conf.blk,
r->sector << BDRV_SECTOR_BITS, &r->qiov,
0, scsi_write_complete, r);
r->req.aiocb = sdc->dma_writev(r->sector << BDRV_SECTOR_BITS, &r->qiov,
scsi_write_complete, r, r);
}
}
@ -2658,12 +2671,35 @@ static int scsi_block_parse_cdb(SCSIDevice *d, SCSICommand *cmd,
#endif
static
BlockAIOCB *scsi_dma_readv(int64_t offset, QEMUIOVector *iov,
BlockCompletionFunc *cb, void *cb_opaque,
void *opaque)
{
SCSIDiskReq *r = opaque;
SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, r->req.dev);
return blk_aio_preadv(s->qdev.conf.blk, offset, iov, 0, cb, cb_opaque);
}
static
BlockAIOCB *scsi_dma_writev(int64_t offset, QEMUIOVector *iov,
BlockCompletionFunc *cb, void *cb_opaque,
void *opaque)
{
SCSIDiskReq *r = opaque;
SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, r->req.dev);
return blk_aio_pwritev(s->qdev.conf.blk, offset, iov, 0, cb, cb_opaque);
}
static void scsi_disk_base_class_initfn(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
SCSIDiskClass *sdc = SCSI_DISK_BASE_CLASS(klass);
dc->fw_name = "disk";
dc->reset = scsi_disk_reset;
sdc->dma_readv = scsi_dma_readv;
sdc->dma_writev = scsi_dma_writev;
}
static const TypeInfo scsi_disk_base_info = {
@ -2671,6 +2707,7 @@ static const TypeInfo scsi_disk_base_info = {
.parent = TYPE_SCSI_DEVICE,
.class_init = scsi_disk_base_class_initfn,
.instance_size = sizeof(SCSIDiskState),
.class_size = sizeof(SCSIDiskClass),
};
#define DEFINE_SCSI_DISK_PROPERTIES() \