Re: [Qemu-devel] [PATCH v13 2/3] migration: Create socket-address parameter

[Eric Blake <eblake@redhat.com>]

On 2/20/19 3:22 AM, Juan Quintela wrote:
> It will be used to store the uri parameters. We want this only for
> tcp, so we don't set it for other uris.  We need it to know what port
> is migration running.
> 
> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> Signed-off-by: Juan Quintela <quintela@redhat.com>
> 
> --

> +++ b/qapi/migration.json
> @@ -6,6 +6,7 @@
>  ##
>  
>  { 'include': 'common.json' }
> +{ 'include': 'sockets.json' }
>  
>  ##
>  # @MigrationStats:
> @@ -199,6 +200,8 @@
>  # @compression: migration compression statistics, only returned if compression
>  #           feature is on and status is 'active' or 'completed' (Since 3.1)
>  #
> +# @socket-address: Only used for tcp, to know what the real port is (Since 4.0)
> +#
>  # Since: 0.14.0
>  ##
>  { 'struct': 'MigrationInfo',
> @@ -213,7 +216,8 @@
>             '*error-desc': 'str',
>             '*postcopy-blocktime' : 'uint32',
>             '*postcopy-vcpu-blocktime': ['uint32'],
> -           '*compression': 'CompressionStats'} }
> +           '*compression': 'CompressionStats',
> +           '*socket-address': ['SocketAddress'] } }
>  

Okay, I actually tried compiling your patch with the following hunk:

>  ##
>  # @query-migrate:
> diff --git a/qapi/sockets.json b/qapi/sockets.json
> index fc81d8d5e8..d7f77984af 100644
> --- a/qapi/sockets.json
> +++ b/qapi/sockets.json
> @@ -152,3 +152,16 @@
>              'unix': 'UnixSocketAddress',
>              'vsock': 'VsockSocketAddress',
>              'fd': 'String' } }
> +
> +##
> +# @DummyStruct:
> +#
> +# Both block-core and migration needs SocketAddressList
> +# I am open to comments about how to share it
> +#
> +# @dummy-list: A dummy list
> +#
> +# Since: 3.1

4.0

> +##
> +{ 'struct': 'DummyStruct',
> +  'data': { 'dummy-list': ['SocketAddress'] } }
> 

removed, and got:

In file included from qapi/qapi-types-migration.c:15:
qapi/qapi-types-migration.h:267:5: error: unknown type name
‘SocketAddressList’
     SocketAddressList *socket_address;
     ^~~~~~~~~~~~~~~~~
make: *** [/home/eblake/qemu/rules.mak:69: qapi/qapi-types-migration.o]
Error 1

That says we have a bug in our QAPI generator - the type
SocketAddressList should be auto-generated at the point where it is
needed in migration.json. Markus, any ideas why we are not properly
auto-generating an array type when the only use of that array comes from
a different module than where the original type was declared?

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org