[Engine-devel] Device custom properties

[Martin Perina]

----- Original Message -----
> From: "Eli Mesika" <emesika at redhat.com>
> To: "Martin Perina" <mperina at redhat.com>
> Cc: engine-devel at ovirt.org
> Sent: Sunday, May 5, 2013 9:18:07 AM
> Subject: Re: [Engine-devel] Device custom properties
> 
> 
> 
> ----- Original Message -----
> > From: "Martin Perina" <mperina at redhat.com>
> > To: engine-devel at ovirt.org
> > Sent: Saturday, May 4, 2013 8:13:44 AM
> > Subject: Re: [Engine-devel] Device custom properties
> > 
> > 
> > 
> > ----- Original Message -----
> > > From: "Martin Perina" <mperina at redhat.com>
> > > To: engine-devel at ovirt.org
> > > Sent: Friday, May 3, 2013 11:06:05 AM
> > > Subject: [Engine-devel] Device custom properties
> > > 
> > > Hi,
> > >  
> > > I'm currently trying to implement device custom properties infrastructure
> > > in
> > > ovirt-engine.
> > > During discussion with Yair, we found out, that it's not clear, for what
> > > type
> > > of devices
> > > custom properties should be available? In engine we have the VmDeviceType
> > > enum which
> > > contains following values:
> > >  
> > >      FLOPPY("floppy", "14"),
> > >      DISK("disk", "17"),
> > >      CDROM("cdrom", "15"),
> > >      INTERFACE("interface", "10"),
> > >      BRIDGE("bridge", "3"),
> > >      VIDEO("video", "20"),
> > >      USB("usb", "23"),
> > >      CONTROLLER("controller", "23"),
> > >      REDIR("redir", "23"),
> > >      SPICEVMC("spicevmc", "23"),
> > >      QXL("qxl"),
> > >      CIRRUS("cirrus"),
> > >      SOUND("sound"),
> > >      ICH6("ich6"),
> > >      AC97("ac97"),
> > >      MEMBALLOON("memballoon"),
> > >      SMARTCARD("smartcard"),
> > >      BALLOON("balloon"),
> > >      OTHER("other", "0"),
> > >      UNKNOWN("unknown", "-1");
> > >  
> > > But VmDevice class has two String attributes device and type. So for
> > > example
> > > a disk is a device
> > > which has device set to disk and type set to disk (according to
> > > VmDeviceCommonUtils.isDisk method).
> > >  
> > > So my question is, if I have a custom properties for disk, will they be
> > > available for all disk
> > > devices (disk, cdrom, floppy, ...) or only for real disk? So should we
> > > support custom properties
> > > for all VmDeviceType enum value separately?
> > > 
> > > Thanks for suggestions
> > > 
> > > Martin
> 
> The reason for that difference is that we had types in the backend code only
> for managed devices . (i.e. devoices that are known and handled by the
> backend)
> Any other device as balloon etc. is considered as unmanaged device , that
> means that VDSM tells us that it exists and therefore tell us its type as
> well...
> 
> 

Ok, I understand this.

But there are also OTHER and UNKNOWN device types in backend, but these types doesn't
corresponds to ANY type in VDSM. I don't want to refactor VmDevice device and type attributes
too much, so is it safe to expect that device attribute of VmDevice can only contain
one of VDSM device types ('disk', 'interface', 'video', 'sound', 'controller', 'balloon',
'channel', 'console', 'smartcard')? It's really important question, because replacing
String type with enum would save a lot of code in device custom properties implementation.

Martin