- /*
- * We can't cancel Scatter Gather DMA in the middle of the
- * operation or a partial (not full) DMA transfer would reach
- * the storage so we wait for completion instead (we beahve
- * like if the DMA was completed by the time the guest trying
- * to cancel dma with bmdma_cmd_writeb with BM_CMD_START not
- * set).
- *
- * In the future we'll be able to safely cancel the I/O if the
- * whole DMA operation will be submitted to disk with a single
- * aio operation with preadv/pwritev.
- */
- if (bm->bus->dma->aiocb) {
- blk_drain_all();
- assert(bm->bus->dma->aiocb == NULL);
- }