Re: [Qemu-block] [Qemu-devel] [PATCH 05/13] qapi: Formalize qcow encryption probing

[Daniel P . Berrangé]

On Thu, May 10, 2018 at 09:24:24AM -0500, Eric Blake wrote:
> On 05/09/2018 11:55 AM, Max Reitz wrote:
> > Currently, you can give no encryption format for a qcow file while still
> > passing a key-secret.  That does not conform to the schema, so this
> > patch changes the schema to allow it.
> > 
> > Signed-off-by: Max Reitz <address@hidden>
> > ---
> 
> >   ##
> >   # @BlockdevQcowEncryptionFormat:
> >   #
> >   # @aes: AES-CBC with plain64 initialization vectors
> >   #
> > +# @from-image:      Determine the encryption format from the image
> > +#                   header.  This only allows the use of the
> > +#                   key-secret option.  (Since: 2.13)
> > +#
> >   # Since: 2.10
> >   ##
> >   { 'enum': 'BlockdevQcowEncryptionFormat',
> > -  'data': [ 'aes' ] }
> > +  'data': [ 'aes', 'from-image' ] }
> 
> Overkill.  Why not just:
> 
> >   ##
> >   # @BlockdevQcowEncryption:
> > @@ -2728,9 +2748,11 @@
> >   # Since: 2.10
> >   ##
> >   { 'union': 'BlockdevQcowEncryption',
> > -  'base': { 'format': 'BlockdevQcowEncryptionFormat' },
> > +  'base': { '*format': 'BlockdevQcowEncryptionFormat' },
> >     'discriminator': 'format',
> > -  'data': { 'aes': 'QCryptoBlockOptionsQCow' } }
> > +  'default-variant': 'from-image',
> 
> 'default-variant': 'aes'
> 
> > +  'data': { 'aes': 'QCryptoBlockOptionsQCow',
> 
> and call it good, because there are no other options to pick from, so
> 'from-image' would always resolve to 'aes' anyway.

Sounds reasonable because qcowv1 is a dead format we don't intend to
add more features to.


Regards,
Daniel
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