> -----Original Message----- > From: Paolo Bonzini [mailto:pbonzini@xxxxxxxxxx] > Sent: Monday, June 4, 2018 6:03 PM > To: Liu, Changpeng <changpeng.liu@xxxxxxxxx>; Stefan Hajnoczi > <stefanha@xxxxxxxxxx> > Cc: virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx; cavery@xxxxxxxxxx; > jasowang@xxxxxxxxxx; Wang, Wei W <wei.w.wang@xxxxxxxxx> > Subject: Re: [PATCH v4] virtio_blk: add DISCARD and WRIET ZEROES commands > support > > On 04/06/2018 06:14, Liu, Changpeng wrote: > >>> But I believe the specification says VIRTIO_BLK_T_OUT means direction, so > >>> OR the two bits together should compliance with the specification. > >> I cannot find that in the specification: > >> > >> http://docs.oasis-open.org/virtio/virtio/v1.0/cs04/virtio-v1.0-cs04.html#x1- > >> 2020002 > >> > >> and it would contradict the "The type of the request is either ... or > >> ..." wording that I quoted from the spec above. > >> > >> If you do find something in the spec, please let me know and we can > >> figure out how to make the spec consistent. > > > > I saw comments from file linux/usr/include/uapi/linux/virtio_blk.h, which says > > VIRTIO_BLK_T_OUT may be combined with other commands and means direction, > > the specification does not have such description. > > I don't think it is in the specification indeed (however, 11 and 13 were > chosen so that VIRTIO_BLK_T_OUT can still indicate direction). Correct, we don't need to OR VIRTIO_BLK_T_OUT again for DISCARD and WRITE ZEROES commands. I'll remove it in next patch set. > > Paolo _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
