Re: [PATCH v3 00/21] Multifd Migration Compression

[Markus Armbruster <armbru@redhat.com>]

Juan Quintela <quintela@redhat.com> writes:

> [v3]
> - rebased on top of upstream + previous multifd cancel series
> - split multifd code into its own file (multifd.[ch])
> - split zstd/zlib compression methods (multifd-zstd/zlib.c)
> - use qemu module feauture to avoid ifdefs
>   (my understanding is that zlib needs to be present, but
>   we setup zstd only if it is not there or is disabled)
> - multifd-method: none|zlib|zstd
>
>   As far as I can see, there is no easy way to convince qapi that zstd
>   option could/couldn't be there depending on compliation flags. I
>   ended just checking in migrate_parameters_check() if it is enabled
>   and giving an error message otherwise.

Wild guess: this is about PATCH 21's

   diff --git a/qapi/migration.json b/qapi/migration.json
   index 1714ea51e3..65db85970e 100644
   --- a/qapi/migration.json
   +++ b/qapi/migration.json
   @@ -499,7 +499,7 @@
    #
    ##
    { 'enum': 'MultifdCompress',
   -  'data': [ 'none', 'zlib' ] }
   +  'data': [ 'none', 'zlib', 'zstd' ] }

    ##
    # @MigrationParameter:

where you want 'zstd' to be #ifdef CONFIG_ZSTD.  If not, please advise.
Else use something like

    { 'enum': 'MultifdCompress',
      'data': [ 'none', 'zlib',
                { 'name': 'zstd', 'if': 'defined(CONFIG_ZSTD)' } ] }

See docs/devel/qapi-code-gen.txt sections "Enumeration types" and
"Configuring the schema".

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