[libvirt] [PATCH 1/2] Add VSCSI bus type and VSCSI controller type for pseries guest.

[Cole Robinson]

On 05/30/2012 02:57 AM, Li Zhang wrote:
> On 05/30/2012 07:25 AM, Cole Robinson wrote:
>> On 05/03/2012 10:05 PM, Li Zhang wrote:
>>> Now, there is only SCSI bus and controller type in libvirt.
>>> And when configuring VSCSI controller, it needs to configure
>>> the spapr-vio bus address type externally. It's a little
>>> inconvenient to configure the controller type.
>>>
>>> This patch is to add VSCSI bus type and VSCSI controller type.
>>> And handle with the problems when VSCSI and SCSI devices
>>> working together, by assign the even number to index of
>>> VSCSI controller and odd number to index of SCSI controller.
>>>
>>> And when the VSCSI controller is always assigned as SPAPRVIO
>>> bus address type and SCSI controller will be always assigned
>>> as PCI bus address, which is implemented according to the
>>> controllers' type.
>>>
>>> So when one disk is based on VSCSI controller, then assign
>>> the bus as 'vscsi', and one right VSCSI controller will be
>>> selected.
>>>
>>> If one disk is based on VSCSI controller, the XML file is
>>> as the following:
>>>
>>> <disk type='file' device='disk'>
>>>     <driver name='qemu' type='raw'/>
>>>     <source file='/path/file'/>
>>>     <target dev='sda' bus='vscsi'/>
>>> </disk>
>>>
>>> VSCSI controllers' configuration in XML file will be like
>>> this:
>>>
>>> <controller type='vscsi' index='0'>
>>> </controller>
>>>
>>> If one disk is based on 'vscsi', the 'vscsi' bus should be assigned
>>> externally. Otherwise, it will be set as 'scsi' bus according
>>> to the 'sd' target prefix of the disk.
>>>
>>
>> First off, sorry for taking so long to respond.
>>
>> This isn't exactly what I had in mind when I recommended a libvirt patch.
>> Change libvirt to add:
>>
>>      <controller type='scsi' index='0'>
>>          <address type='spapr-vio'/>
>>      </controller>
>>
>> when the guest XML has
>>
>> <disk type='file' device='disk'>
>>      <driver name='qemu' type='raw'/>
>>      <source file='/path/file'/>
>>      <target dev='sda' bus='scsi'/>
>>      <address type='spapr-vio'/>
>> </disk>
>>
>> and the guest XML doesn't already have spapr-vio<controller>.
> 
> Thanks a lot for your suggestion. :)
> 
> I see the libvirt will always set the address type of the disk as
> "drive". There is one drive address structure in libvirt, which
> records the controller, bus and unit.
> 
> the address can be specified in the target.
> 
>  <disk type='file' device='disk'>
>       <driver name='qemu' type='raw'/>
>       <source file='/path/file'/>
>       <target dev='sda' bus='scsi' address='spapr-vio'/>
>       <address type='drive' controller='0' bus='0' unit='0' />
>  </disk>
> 

That sounds okay to me, bug maybe eblake or danpb should sign off on it
conceptually, since it's a new XML element.

- Cole