Re: [PATCHv3 04/11] Add virtio revision attribute to controllers

[Ján Tomko <jtomko@xxxxxxxxxx>]

On Thu, Aug 11, 2016 at 10:17:34AM -0400, Laine Stump wrote:
> On 08/11/2016 09:31 AM, Daniel P. Berrange wrote:
> > On Thu, Aug 11, 2016 at 03:25:53PM +0200, Ján Tomko wrote:
> > > On Thu, Aug 11, 2016 at 01:00:08PM +0100, Daniel P. Berrange wrote:
> > > > On Wed, Aug 10, 2016 at 03:27:15PM +0200, Ján Tomko wrote:
> > > > > <controller type='scsi' index='0' model='virtio-scsi'>
> > > > >      <virtio revision='0.9'/>
> > > > I'm wondering about generalizing this. eg what if there are
> > > > other device models where we want the ability to set a
> > > > revision. We don't really want to invent a new sub-elment
> > > > named after each device model
> > > Not even a new attribute? :)
> > >   <revision virtio='0.9'/>
> > >
> > > How about:
> > >   <revision type='virtio' version='0.9'/>
> > Both of those are quite repetative - we already know its virtio.
> >
> > Most devices we have alrady include a <driver> or <model> sub-element,
> > so we should really just add a revision= attrbute to those existing
> > elements. For places which don't already have this we can add a new
> > <driver> element
>
> Yeah, I was going to suggest <driver> as well.
>
> The only thing missing would be the ability to specify multiple versions.

I think that's something we want to allow - didn't you mention somewhere
that 'disable-legacy=off,disable-modern=off' gets different results than
omitting it completely?

Other than awkward enum values, it could be represented as a (rather
verbose) subelement:
<driver>
 <revision>0.9</revision>
 <revision>1.0</revision>
</driver>

> Also, it does make the parsing and formatting a bit awkward, since
> <driver> has different parse/format functions for each device that uses
> it (necessary due to the difference in possible attributes).

That means more work for me, but should not be a factor when deciding
on better-looking XML.

> In spite of that, it would definitely look better from the outside.

Personally I liked the consistence of having the same element under each
device more (and the ability to have more of them), but putting it under
<driver>/<model> also has its beauty, if we can figure out how to
express multiple versions.

Jan

Attachment: signature.asc
Description: Digital signature

--
libvir-list mailing list
libvir-list@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/libvir-list