static void virtio_blk_submit_multireq(BlockBackend *blk, MultiReqBuffer *mrb)
{
int i = 0, start = 0, num_reqs = 0, niov = 0, nb_sectors = 0;
uint32_t max_transfer;
int64_t sector_num = 0;
if (mrb->num_reqs == 1) {
submit_requests(blk, mrb, 0, 1, -1);
mrb->num_reqs = 0;
return;
}
max_transfer = blk_get_max_transfer(mrb->reqs[0]->dev->blk);
qsort(mrb->reqs, mrb->num_reqs, sizeof(*mrb->reqs),
&multireq_compare);
for (i = 0; i < mrb->num_reqs; i++) {
VirtIOBlockReq *req = mrb->reqs[i];
if (num_reqs > 0) {
/*
* NOTE: We cannot merge the requests in below situations:
* 1. requests are not sequential
* 2. merge would exceed maximum number of IOVs
* 3. merge would exceed maximum transfer length of backend device
*/
if (sector_num + nb_sectors != req->sector_num ||
niov > blk_get_max_iov(blk) - req->qiov.niov ||
req->qiov.size > max_transfer ||
nb_sectors > (max_transfer -
req->qiov.size) / BDRV_SECTOR_SIZE) {
submit_requests(blk, mrb, start, num_reqs, niov);
num_reqs = 0;
}
}
if (num_reqs == 0) {
sector_num = req->sector_num;
nb_sectors = niov = 0;
start = i;
}
nb_sectors += req->qiov.size / BDRV_SECTOR_SIZE;
niov += req->qiov.niov;
num_reqs++;
}
submit_requests(blk, mrb, start, num_reqs, niov);
mrb->num_reqs = 0;
}
static void scsi_read_complete(void * opaque, int ret)
{
SCSIGenericReq *r = (SCSIGenericReq *)opaque;
SCSIDevice *s = r->req.dev;
int len;
assert(r->req.aiocb != NULL);
r->req.aiocb = NULL;
aio_context_acquire(blk_get_aio_context(s->conf.blk));
if (ret || r->req.io_canceled) {
scsi_command_complete_noio(r, ret);
goto done;
}
len = r->io_header.dxfer_len - r->io_header.resid;
DPRINTF("Data ready tag=0x%x len=%d\n", r->req.tag, len);
r->len = -1;
if (len == 0) {
scsi_command_complete_noio(r, 0);
goto done;
}
/* Snoop READ CAPACITY output to set the blocksize. */
if (r->req.cmd.buf[0] == READ_CAPACITY_10 &&
(ldl_be_p(&r->buf[0]) != 0xffffffffU || s->max_lba == 0)) {
s->blocksize = ldl_be_p(&r->buf[4]);
s->max_lba = ldl_be_p(&r->buf[0]) & 0xffffffffULL;
} else if (r->req.cmd.buf[0] == SERVICE_ACTION_IN_16 &&
(r->req.cmd.buf[1] & 31) == SAI_READ_CAPACITY_16) {
s->blocksize = ldl_be_p(&r->buf[8]);
s->max_lba = ldq_be_p(&r->buf[0]);
}
blk_set_guest_block_size(s->conf.blk, s->blocksize);
/* Patch MODE SENSE device specific parameters if the BDS is opened
* readonly.
*/
if ((s->type == TYPE_DISK || s->type == TYPE_TAPE) &&
blk_is_read_only(s->conf.blk) &&
(r->req.cmd.buf[0] == MODE_SENSE ||
r->req.cmd.buf[0] == MODE_SENSE_10) &&
(r->req.cmd.buf[1] & 0x8) == 0) {
if (r->req.cmd.buf[0] == MODE_SENSE) {
r->buf[2] |= 0x80;
} else {
r->buf[3] |= 0x80;
}
}
if (s->type == TYPE_DISK &&
r->req.cmd.buf[0] == INQUIRY &&
r->req.cmd.buf[2] == 0xb0) {
uint32_t max_transfer =
blk_get_max_transfer(s->conf.blk) / s->blocksize;
assert(max_transfer);
stl_be_p(&r->buf[8], max_transfer);
/* Also take care of the opt xfer len. */
stl_be_p(&r->buf[12],
MIN_NON_ZERO(max_transfer, ldl_be_p(&r->buf[12])));
}
scsi_req_data(&r->req, len);
scsi_req_unref(&r->req);
done:
aio_context_release(blk_get_aio_context(s->conf.blk));
}
