[libvirt] [PATCH 15/34] Auto-add disk controllers based on defined disks

[Daniel P. Berrange]

On Fri, Jan 15, 2010 at 04:24:16PM +0100, Daniel Veillard wrote:
> On Fri, Jan 08, 2010 at 05:23:11PM +0000, Daniel P. Berrange wrote:
> > Existing applications using libvirt are not aware of the disk
> > controller concept. Thus, after parsing the <disk> definitions
> > in the XML, it is neccessary to create <controller> elements
> > to satisfy all requested disks, as per their defined drive
> > addresses
> > 
> > * src/conf/domain_conf.c, src/conf/domain_conf.h,
> >   src/libvirt_private.syms: Add virDomainDefAddDiskControllers()
> >   method for populating disk controllers, and call it after
> >   parsing disk definitions.
> > * src/qemu/qemu_conf.c: Call virDomainDefAddDiskControllers()
> >   when doing ARGV -> XML conversion
> > * tests/qemuxml2argvdata/qemuxml2argv*.xml: Add disk controller
> >   data to all data files which don't have it already
> 
> > +/*
> > + * Based on the declared <address type=drive> info for any disks,
> > + * add neccessary drive controllers which are not already present
> > + * in the XML. This is for compat with existing apps which will
> > + * not know/care about <controller> info in the XML
> > + */
> > +int virDomainDefAddDiskControllers(virDomainDefPtr def)
> > +{
> > +    if (virDomainDefAddDiskControllersForType(def,
> > +                                              VIR_DOMAIN_CONTROLLER_TYPE_SCSI,
> > +                                              VIR_DOMAIN_DISK_BUS_SCSI) < 0)
> > +        return -1;
> > +
> > +    if (virDomainDefAddDiskControllersForType(def,
> > +                                              VIR_DOMAIN_CONTROLLER_TYPE_FDC,
> > +                                              VIR_DOMAIN_DISK_BUS_FDC) < 0)
> > +        return -1;
> > +
> > +    if (virDomainDefAddDiskControllersForType(def,
> > +                                              VIR_DOMAIN_CONTROLLER_TYPE_IDE,
> > +                                              VIR_DOMAIN_DISK_BUS_IDE) < 0)
> > +        return -1;
> > +
> > +    return 0;
> > +}
> 
> IIRC a previous patch in the serie disk controler are not sorted,
> so the order here is just arbitrary, right ?

The code is not sorting controller types, merely controller indexes
within a given type. So SCSI / FDC / IDE can appear in any order,
but if you add an extra controller of type 'SCSI', it will be inserted
in correct position wrt existing SCSI controllers.

> 
> 
> > --- a/tests/qemuxml2argvdata/qemuxml2argv-floppy-drive-fat.xml
> > +++ b/tests/qemuxml2argvdata/qemuxml2argv-floppy-drive-fat.xml
> > @@ -21,5 +21,7 @@
> >        <readonly/>
> >        <address type='drive' controller='0' bus='0' unit='0'/>
> >      </disk>
> > +    <controller type='ide' index='0'/>
> > +    <controller type='fdc' index='0'/>
> >    </devices>
> >  </domain>
> 
>   strange here in the output we get ide before fdc, I would have assume
> the reverse based on the new function. I hope the order in generated
> output won't change randomly.
> 
>   Except that remark looks fine, ACK,


Daniel
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