[libvirt] [PATCH RFC 2/5] conf: Introduce scsi hostdev

[Han Cheng]

On 03/06/2013 02:24 PM, Osier Yang wrote:
> On 2013年03月04日 14:01, Han Cheng wrote:
>> Adding scsi hostdev, it should like:
>>
>>       <hostdev mode='subsystem' type='scsi'>
>>         <source>
>>           <adapter name='scsi_host0'/>
>>           <address bus='0' target='0' unit='0'/>
>>         </source>
>>         <address type='drive' controller='0' bus='0' target='4' unit='8'/>
>>       </hostdev>
>> @@ -3893,4 +3921,9 @@
>>        </element>
>>        <empty/>
>>      </define>
>> +<define name="scsiAdapter">
>> +<data type="string">
>> +<param name="pattern">scsi_host[0-9]{1,2}</param>
> 
> No need to have a duplicate definition. It can reuse what
> storage pool uses.
> 
This is possible.
But what make differences is the number. If we don't deal with it and
storage it as string, we'll have to deal with it when build command line.

Or， we just change the xml:
      <source>
        <adapter name='scsi_host0'/>
        <address bus='0' target='0' unit='0'/>
      </source>
-->
      <source>
        <address host='0' bus='0' target='0' unit='0'/>
      </source>

And actually 'host' can be 'controller'. Then it is drive address. We
may reduce redundant codes.

>> @@ -12997,6 +13119,15 @@ virDomainHostdevDefFormatSubsys(virBufferPtr buf,
>>        virBufferAdjustIndent(buf, 2);
>>        switch (def->source.subsys.type)
>>        {
>> +    case VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_SCSI:
>> +        virBufferAsprintf(buf, "<adapter name='scsi_host%d'/>\n",
> 
> This is hard code. Assuming that a scsi host device can have different
> name with "scsi_host" on platform other than Linux. So again, IMHO
> we should just storing the adapter name as string.
> 
Actually I'm quite uncomfortable when writing this hard code. If we
change xml, this won't be problem.