[libvirt] [PATCHv2 2/2] qemu: add new disk device='lun' for bus='virtio' & type='block'

[Laine Stump]

On 01/05/2012 11:10 AM, Paolo Bonzini wrote:
> On 01/05/2012 04:59 PM, Laine Stump wrote:
>> On 01/05/2012 03:44 AM, Paolo Bonzini wrote:
>>> Summary: two nits, one in the docs and one at the end of this email.
>>>
>>> [Osier, I'm CCing you because there is some food for thought for SCSI].
>>>
>>> On 01/05/2012 05:17 AM, Laine Stump wrote:
>>>> diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in
>>>> index 18b7e22..dcdf91f 100644
>>>> --- a/docs/formatdomain.html.in
>>>> +++ b/docs/formatdomain.html.in
>>>> @@ -1001,8 +1001,16 @@
>>>> "block", "dir", or "network"
>>>> and refers to the underlying source for the disk. The optional
>>>> <code>device</code> attribute indicates how the disk is to be exposed
>>>> - to the guest OS. Possible values for this attribute are "floppy",
>>>> "disk"
>>>> - and "cdrom", defaulting to "disk". The
>>>> + to the guest OS. Possible values for this attribute are
>>>> + "floppy", "disk", "cdrom", and "lun", defaulting to
>>>> + "disk". "lun" (<span class="since">since 0.9.10</span>) is only
>>>> + valid when type is "block" and the target element's "bus"
>>>> + attribute is "virtio", and behaves identically to "disk",
>>>> + except that generic SCSI commands from the guest are accepted
>>> What about "are forwarded to the disk"?
>>
>> Okay, I'm adding that to the end of the sentence.
>>
>>
>>> This is also true in the SCSI
>>> case (for SCSI, "block" will emulate commands rather than fail them; 
>>> but
>>> for "lun" the behavior is identical).
>>
>> We can add that to the docs when virtio-blk-scsi support is added.
>
> Actually, there's already support for SCSI devices with device='disk' 
> or device='cdrom', just not for the virtio implementation of SCSI.  So 
> it could be added now.


It sounds like you're saying that when device='disk' & type='block' and 
dev='[some physical SCSI device], sg_io commands will be emulated for 
that device. That doesn't make sense, so you must be saying something else.