> If requests are placed on arbitrary queues you'll inevitably run on > locking issues to ensure strict request ordering. > I would add here: > > If a device uses more than one queue it is the responsibility of the > device to ensure strict request ordering. Applied with s/device/guest/g. > Please do not rely in bus/target/lun here. These are leftovers from > parallel SCSI and do not have any meaning on modern SCSI > implementation (eg FC or SAS). Rephrase that to > > The lun field is the Logical Unit Number as defined in SAM. Ok. > > The status byte is written by the device to be the SCSI status > > code. > > ?? I doubt that exists. Make that: > > The status byte is written by the device to be the status code as > defined in SAM. Ok. > > The response byte is written by the device to be one of the > > following: > > > > - VIRTIO_SCSI_S_OK when the request was completed and the > > status byte > > is filled with a SCSI status code (not necessarily "GOOD"). > > > > - VIRTIO_SCSI_S_UNDERRUN if the content of the CDB requires > > transferring > > more data than is available in the data buffers. > > > > - VIRTIO_SCSI_S_ABORTED if the request was cancelled due to a > > reset > > or another task management function. > > > > - VIRTIO_SCSI_S_FAILURE for other host or guest error. In > > particular, > > if neither dataout nor datain is empty, and the > > VIRTIO_SCSI_F_INOUT > > feature has not been negotiated, the request will be > > immediately > > returned with a response equal to VIRTIO_SCSI_S_FAILURE. > > > And, of course: > > VIRTIO_SCSI_S_DISCONNECT if the request could not be processed due > to a communication failure (eg device was removed or could not be > reached). Ok. > This specification implies a strict one-to-one mapping between host > and target. IE there is no way of specifying more than one target > per host. Actually no, the intention is to use hierarchical LUNs to support more than one target per host. Paolo _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/virtualization
