On Tue, May 29, 2018 at 09:42:24AM +0800, Changpeng Liu wrote:
> num = blk_rq_map_sg(hctx->queue, req, vbr->sg);
> if (num) {
> - if (rq_data_dir(req) == WRITE)
> + if (rq_data_dir(req) == WRITE || type == VIRTIO_BLK_T_DISCARD ||
> + type == VIRTIO_BLK_T_WRITE_ZEROES)
> vbr->out_hdr.type |= cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_OUT);
The VIRTIO specification says:
The type of the request is either a read (VIRTIO_BLK_T_IN), a write
(VIRTIO_BLK_T_OUT), a discard (VIRTIO_BLK_T_DISCARD), a write zeroes
(VIRTIO_BLK_T_WRITE_ZEROES) or a flush (VIRTIO_BLK_T_FLUSH).
But this patch actually uses VIRTIO_BLK_T_DISCARD | VIRTIO_BLK_T_OUT or
VIRTIO_BLK_T_WRITE_ZEROES | VIRTIO_BLK_T_OUT. "either A or B" is
exclusive, it does not mean "A and B".
Can you clarify whether the spec needs to be changed or what the purpose
of ORing in the VIRTIO_BLK_T_OUT bit is?
Attachment:
signature.asc
Description: PGP signature
_______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
