Re: [Qemu-devel] [Patch v3 01/30] qmp: details about CPU definitions in query-cpu-definitions

[David Hildenbrand]

> On 08/24/2016 01:10 PM, David Hildenbrand wrote:
> > It might be of interest for tooling whether a CPU definition can be safely
> > used when migrating, or if e.g. CPU features might get lost during
> > migration when migrationg from/to a different QEMU version or host, even if
> > the same compatibility machine is used.
> > 
> > Also, we want to know if a CPU definition is static and will never change.
> > Beause these definitions can then be used independantly of a compatibility
> > machine and will always have the same feature set, they can e.g. be used
> > to indicate the "host" model in libvirt later on.
> > 
> > Let's add two return values to query-cpu-definitions, stating for each
> > returned CPU definition, if it is migration-safe and if it is static.
> > 
> > While "migration-safe" is optional, "static" will be set to "false"
> > automatically by all implementing architectures. If a model really was
> > static all the time and will be in the future, this can simply be changed
> > later.
> > 
> > Signed-off-by: David Hildenbrand <address@hidden>
> > ---
> >  qapi-schema.json | 14 +++++++++++++-
> >  1 file changed, 13 insertions(+), 1 deletion(-)
> > 
> > diff --git a/qapi-schema.json b/qapi-schema.json
> > index 5658723..0d9ae50 100644
> > --- a/qapi-schema.json
> > +++ b/qapi-schema.json
> > @@ -3038,10 +3038,22 @@
> >  #
> >  # @name: the name of the CPU definition
> >  #
> > +# @migration-safe: #optional whether a CPU definition can be safely used 
> > for
> > +#                  migration in combination with a QEMU compatibility 
> > machine
> > +#                  when migrating between different QMU versions and 
> > between
> > +#                  hosts  with different sets of (hardware or software)  
> 
> Why two spaces after 'hosts'?
> 
> > +#                  capabilities. If not provided, information is not 
> > available
> > +#                  and callers should not assume the CPU definition to be
> > +#                  migration-safe.  
> 
> Missing a '(since 2.8)' designation (at least, I'm assuming this is 2.8
> material).
> 
> > +#
> > +# @static: whether a CPU definition is static and will not change 
> > depending on
> > +#          QEMU version, machine type, machine options and accelerator 
> > options.
> > +#          A static model is always migration-safe.  
> 
> Likewise missing a since tag.
> 
> > +#
> >  # Since: 1.2.0
> >  ##
> >  { 'struct': 'CpuDefinitionInfo',
> > -  'data': { 'name': 'str' } }
> > +  'data': { 'name': 'str', '*migration-safe' : 'bool', 'static' : 'bool' } 
> > }  
> 
> We aren't consistent on whether to use space before ':' or to put it
> flush against the key, but it's at least nice to be consistent within a
> single line.
> 

All valid and fixed!

Thanks for having a look!

David