Messages in this thread | | | Date | Mon, 19 Dec 2011 14:11:42 +0100 | From | Paolo Bonzini <> | Subject | Re: [PATCH v3 1/2] virtio-scsi: first version |
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On 12/19/2011 01:22 PM, Hannes Reinecke wrote: >> + case VIRTIO_SCSI_S_UNDERRUN: >> + set_host_byte(sc, DID_ERROR); >> + break; > Hmm. Not sure this is correct. > UNDERRUN could be a valid state, eg it is quite common to send > an INQUIRY with a length of 255 bytes. And only evaluate the > bytes which are actually send back.
This happens when you send an INQUIRY with a sglist of 255 bytes and an ALLOCATION LENGTH of 300 bytes. The spec says "VIRTIO_SCSI_S_UNDERRUN [is returned] if the content of the CDB requires transferring more data than is available in the data buffers".
> And, it's not good style to match the same DID_XXX error code to > several internal errors. I would prefer having a 1:1 match for > VIRTIO_SCSI_S_XXX and DID_XXX error codes.
There is no DID_XXX value for underrun, but it's quite useful to have it diagnosed separately in traces.
>> +static struct scsi_host_template virtscsi_host_template = { >> + .module = THIS_MODULE, >> + .name = "Virtio SCSI HBA", >> + .proc_name = "virtio_scsi", >> + .queuecommand = virtscsi_queuecommand, >> + .this_id = -1, >> + >> + .can_queue = 1024, >> + .dma_boundary = UINT_MAX, >> + .use_clustering = ENABLE_CLUSTERING, >> +}; >> + > Hmm. Apparently you support more than one LUN, yet no > ->slave_alloc() callback is present. So how do you scan the bus here?
What does slave_alloc have to do with scanning? I don't need hostdata, so I don't have slave_alloc.
Scanning is here:
err = scsi_add_host(shost, &vdev->dev); if (err) goto scsi_add_host_failed;
scsi_scan_host(shost);
> Do you actually have a working backend implementation?
Hmm... yes, of course...
Paolo
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