[SLOF] [PATCH] vio-vscsi: Support multiple channels / buses

[Alexey Kardashevskiy]

On 10/01/2019 17:21, Thomas Huth wrote:
> On 2019-01-10 00:59, Alexey Kardashevskiy wrote:
>>
>>
>> On 10/01/2019 04:05, Thomas Huth wrote:
>>> The spapr-vscsi device of QEMU supports multiple channels (a.k.a. buses).
>>
>>
>> What about virtio-scsi?
> 
> While in hw/scsi/spapr_vscsi.c you can find ".max_channel = 7", virtio-scsi
> in QEMU does not have these channels:
> 
> $ grep -r VIRTIO_SCSI_MAX_CHANNEL include hw
> include/hw/virtio/virtio-scsi.h:#define VIRTIO_SCSI_MAX_CHANNEL 0
> hw/scsi/virtio-scsi.c:    virtio_stw_p(vdev, &scsiconf->max_channel, VIRTIO_SCSI_MAX_CHANNEL);
> hw/scsi/virtio-scsi.c:    .max_channel = VIRTIO_SCSI_MAX_CHANNEL,
> 
> And in the virtio spec:
> 
> "When used to address a target and logical unit, the only supported format for lun is: first byte set to 1,
> second byte set to target, third and fourth byte representing a single level LUN structure, followed by four
> zero bytes.
> 
> According to SAM5, "single level LUN" means no bus or channel or whatsoever.

Ah, cool. Thanks for the explanation and the fix.



-- 
Alexey