Re: [Qemu-devel] [PATCH 1/3] qapi: SupportStatusInfo struct

[Eduardo Habkost]

On Wed, Apr 24, 2019 at 12:23:33AM +0200, Philippe Mathieu-Daudé wrote:
> Hi Eduardo,
> 
> On 4/23/19 11:22 PM, Eduardo Habkost wrote:
> > This struct will be used to represent support and deprecation
> > status of QEMU features.
> 
> Excellent idea!
> 
> > 
> > Signed-off-by: Eduardo Habkost <address@hidden>
> > ---
> >  qapi/common.json | 24 ++++++++++++++++++++++++
> >  1 file changed, 24 insertions(+)
> > 
> > diff --git a/qapi/common.json b/qapi/common.json
> > index 99d313ef3b..b59d0dc66b 100644
> > --- a/qapi/common.json
> > +++ b/qapi/common.json
> > @@ -193,3 +193,27 @@
> >               'ppc64', 'riscv32', 'riscv64', 's390x', 'sh4',
> >               'sh4eb', 'sparc', 'sparc64', 'tricore', 'unicore32',
> >               'x86_64', 'xtensa', 'xtensaeb' ] }
> > +
> > +##
> > +# @SupportStatusInfo:
> > +#
> > +# Information on support status of a given feature
> > +# (e.g. machine type)
> 
> Hopefully it is generic, we can use it for devices too.

Yes, I want to keep it generic.

> 
> > +#
> > +# @deprecated: if true, the given feature is deprecated and may be removed
> > +#              in future versions of QEMU according to the QEMU deprecation
> > +#              policy.
> > +#
> > +# @status-message: Human readable message describing support status
> > +#                  of the feature.
> > +#
> > +# @suggested-alternative: Optional.  Suggested alternative for a deprecated
> > +#                         feature.  For machine types, this should be the 
> > name
> > +#                         of an available machine-type.
> > +#
> > +# Since: 4.1
> > +##
> > +{ 'struct': 'SupportStatusInfo',
> > +  'data': { 'deprecated': 'bool',
> > +            '*status-message': 'str',
> 
> This one shouldn't be optional IMHO, we should enforce developpers to
> give a reason for their deprecation.
> 
> With this argument not optional:
> 
> Reviewed-by: Philippe Mathieu-Daudé <address@hidden>

I might agree with you if you show me what would be a good
"reason for deprecation" string for pc-0.15 and spapr.  :)

The only information contained in these machines today is "use
another machine instead", and this is already encoded in the
suggested-alternative field.

-- 
Eduardo