static int coroutine_fn raw_co_writev_flags(BlockDriverState *bs, int64_t sector_num, int nb_sectors, QEMUIOVector *qiov, int flags) { void *buf = NULL; BlockDriver *drv; QEMUIOVector local_qiov; int ret; if (bs->probed && sector_num == 0) { /* As long as these conditions are true, we can't get partial writes to * the probe buffer and can just directly check the request. */ QEMU_BUILD_BUG_ON(BLOCK_PROBE_BUF_SIZE != 512); QEMU_BUILD_BUG_ON(BDRV_SECTOR_SIZE != 512); if (nb_sectors == 0) { /* qemu_iovec_to_buf() would fail, but we want to return success * instead of -EINVAL in this case. */ return 0; } buf = qemu_try_blockalign(bs->file->bs, 512); if (!buf) { ret = -ENOMEM; goto fail; } ret = qemu_iovec_to_buf(qiov, 0, buf, 512); if (ret != 512) { ret = -EINVAL; goto fail; } drv = bdrv_probe_all(buf, 512, NULL); if (drv != bs->drv) { ret = -EPERM; goto fail; } /* Use the checked buffer, a malicious guest might be overwriting its * original buffer in the background. */ qemu_iovec_init(&local_qiov, qiov->niov + 1); qemu_iovec_add(&local_qiov, buf, 512); qemu_iovec_concat(&local_qiov, qiov, 512, qiov->size - 512); qiov = &local_qiov; } BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO); ret = bdrv_co_do_pwritev(bs->file->bs, sector_num * BDRV_SECTOR_SIZE, nb_sectors * BDRV_SECTOR_SIZE, qiov, flags); fail: if (qiov == &local_qiov) { qemu_iovec_destroy(&local_qiov); } qemu_vfree(buf); return ret; }
static inline void submit_requests(BlockBackend *blk, MultiReqBuffer *mrb, int start, int num_reqs, int niov) { QEMUIOVector *qiov = &mrb->reqs[start]->qiov; int64_t sector_num = mrb->reqs[start]->sector_num; int nb_sectors = mrb->reqs[start]->qiov.size / BDRV_SECTOR_SIZE; bool is_write = mrb->is_write; if (num_reqs > 1) { int i; struct iovec *tmp_iov = qiov->iov; int tmp_niov = qiov->niov; /* mrb->reqs[start]->qiov was initialized from external so we can't * modifiy it here. We need to initialize it locally and then add the * external iovecs. */ qemu_iovec_init(qiov, niov); for (i = 0; i < tmp_niov; i++) { qemu_iovec_add(qiov, tmp_iov[i].iov_base, tmp_iov[i].iov_len); } for (i = start + 1; i < start + num_reqs; i++) { qemu_iovec_concat(qiov, &mrb->reqs[i]->qiov, 0, mrb->reqs[i]->qiov.size); mrb->reqs[i - 1]->mr_next = mrb->reqs[i]; nb_sectors += mrb->reqs[i]->qiov.size / BDRV_SECTOR_SIZE; } assert(nb_sectors == qiov->size / BDRV_SECTOR_SIZE); trace_virtio_blk_submit_multireq(mrb, start, num_reqs, sector_num, nb_sectors, is_write); block_acct_merge_done(blk_get_stats(blk), is_write ? BLOCK_ACCT_WRITE : BLOCK_ACCT_READ, num_reqs - 1); } if (is_write) { blk_aio_writev(blk, sector_num, qiov, nb_sectors, virtio_blk_rw_complete, mrb->reqs[start]); } else { blk_aio_readv(blk, sector_num, qiov, nb_sectors, virtio_blk_rw_complete, mrb->reqs[start]); } }
static coroutine_fn int vhdx_co_readv(BlockDriverState *bs, int64_t sector_num, int nb_sectors, QEMUIOVector *qiov) { BDRVVHDXState *s = bs->opaque; int ret = 0; VHDXSectorInfo sinfo; uint64_t bytes_done = 0; QEMUIOVector hd_qiov; qemu_iovec_init(&hd_qiov, qiov->niov); qemu_co_mutex_lock(&s->lock); while (nb_sectors > 0) { /* We are a differencing file, so we need to inspect the sector bitmap * to see if we have the data or not */ if (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) { /* not supported yet */ ret = -ENOTSUP; goto exit; } else { vhdx_block_translate(s, sector_num, nb_sectors, &sinfo); qemu_iovec_reset(&hd_qiov); qemu_iovec_concat(&hd_qiov, qiov, bytes_done, sinfo.bytes_avail); /* check the payload block state */ switch (s->bat[sinfo.bat_idx] & VHDX_BAT_STATE_BIT_MASK) { case PAYLOAD_BLOCK_NOT_PRESENT: /* fall through */ case PAYLOAD_BLOCK_UNDEFINED: /* fall through */ case PAYLOAD_BLOCK_UNMAPPED: /* fall through */ case PAYLOAD_BLOCK_ZERO: /* return zero */ qemu_iovec_memset(&hd_qiov, 0, 0, sinfo.bytes_avail); break; case PAYLOAD_BLOCK_FULL_PRESENT: qemu_co_mutex_unlock(&s->lock); ret = bdrv_co_readv(bs->file, sinfo.file_offset >> BDRV_SECTOR_BITS, sinfo.sectors_avail, &hd_qiov); qemu_co_mutex_lock(&s->lock); if (ret < 0) { goto exit; } break; case PAYLOAD_BLOCK_PARTIALLY_PRESENT: /* we don't yet support difference files, fall through * to error */ default: ret = -EIO; goto exit; break; } nb_sectors -= sinfo.sectors_avail; sector_num += sinfo.sectors_avail; bytes_done += sinfo.bytes_avail; } } ret = 0; exit: qemu_co_mutex_unlock(&s->lock); qemu_iovec_destroy(&hd_qiov); return ret; }