Re: [Qemu-devel] [PATCH v3 1/2] migration: Create tcp_port parameter

[Peter Xu]

On Fri, Dec 01, 2017 at 01:57:49PM +0100, Juan Quintela wrote:
> It will be used to store the uri tcp_port parameter.  This is the only
> parameter than can change and we can need to be able to connect to it.
> 
> Signed-off-by: Juan Quintela <address@hidden>
> 
> --
> 
> This used to be uri parameter, but it has so many troubles to
> reproduce that it don't just make sense.
> ---
>  hmp.c                 |  7 +++++++
>  migration/migration.c | 10 ++++++++++
>  qapi/migration.json   | 19 ++++++++++++++++---
>  3 files changed, 33 insertions(+), 3 deletions(-)
> 
> diff --git a/hmp.c b/hmp.c
> index 1727c9c003..6387d6d517 100644
> --- a/hmp.c
> +++ b/hmp.c
> @@ -345,6 +345,9 @@ void hmp_info_migrate_parameters(Monitor *mon, const 
> QDict *qdict)
>          monitor_printf(mon, "%s: %" PRIu64 "\n",
>              MigrationParameter_str(MIGRATION_PARAMETER_XBZRLE_CACHE_SIZE),
>              params->xbzrle_cache_size);
> +        monitor_printf(mon, "%s: %d\n",
> +            MigrationParameter_str(MIGRATION_PARAMETER_TCP_PORT),
> +            params->tcp_port);
>      }
>  
>      qapi_free_MigrationParameters(params);
> @@ -1659,6 +1662,10 @@ void hmp_migrate_set_parameter(Monitor *mon, const 
> QDict *qdict)
>          }
>          p->xbzrle_cache_size = cache_size;
>          break;
> +    case MIGRATION_PARAMETER_TCP_PORT:
> +        p->has_tcp_port = true;
> +        visit_type_uint16(v, param, &p->tcp_port, &err);

Should we allow user to set this parameter?  Or it's just used for
query, only?  (AFAIU from next patch, this is only used for query)

> +        break;
>      default:
>          assert(0);
>      }
> diff --git a/migration/migration.c b/migration/migration.c
> index 19917a4b5b..abc02d4efd 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -517,6 +517,8 @@ MigrationParameters *qmp_query_migrate_parameters(Error 
> **errp)
>      params->x_multifd_page_count = s->parameters.x_multifd_page_count;
>      params->has_xbzrle_cache_size = true;
>      params->xbzrle_cache_size = s->parameters.xbzrle_cache_size;
> +    params->has_tcp_port = true;
> +    params->tcp_port = s->parameters.tcp_port;
>  
>      return params;
>  }
> @@ -884,6 +886,9 @@ static void 
> migrate_params_test_apply(MigrateSetParameters *params,
>      if (params->has_xbzrle_cache_size) {
>          dest->xbzrle_cache_size = params->xbzrle_cache_size;
>      }
> +    if (params->has_tcp_port) {
> +        dest->tcp_port = params->tcp_port;
> +    }
>  }
>  
>  static void migrate_params_apply(MigrateSetParameters *params, Error **errp)
> @@ -956,6 +961,9 @@ static void migrate_params_apply(MigrateSetParameters 
> *params, Error **errp)
>          s->parameters.xbzrle_cache_size = params->xbzrle_cache_size;
>          xbzrle_cache_resize(params->xbzrle_cache_size, errp);
>      }
> +    if (params->has_tcp_port) {
> +        s->parameters.tcp_port = params->tcp_port;
> +    }
>  }
>  
>  void qmp_migrate_set_parameters(MigrateSetParameters *params, Error **errp)
> @@ -2422,6 +2430,8 @@ static Property migration_properties[] = {
>      DEFINE_PROP_SIZE("xbzrle-cache-size", MigrationState,
>                        parameters.xbzrle_cache_size,
>                        DEFAULT_MIGRATE_XBZRLE_CACHE_SIZE),
> +    DEFINE_PROP_UINT16("x-tcp-port", MigrationState,
> +                       parameters.tcp_port, 0),

Same question here...  If it's only for querying, why allow user to
specify it?

Thanks,

>  
>      /* Migration capabilities */
>      DEFINE_PROP_MIG_CAP("x-xbzrle", MIGRATION_CAPABILITY_XBZRLE),
> diff --git a/qapi/migration.json b/qapi/migration.json
> index 4cd3d13158..e2a1d86216 100644
> --- a/qapi/migration.json
> +++ b/qapi/migration.json
> @@ -488,6 +488,9 @@
>  #                     and a power of 2
>  #                     (Since 2.11)
>  #
> +# @tcp-port: Only used for tcp, to know what is the real port
> +#                     (Since 2.12)
> +#
>  # Since: 2.4
>  ##
>  { 'enum': 'MigrationParameter',
> @@ -496,7 +499,7 @@
>             'tls-creds', 'tls-hostname', 'max-bandwidth',
>             'downtime-limit', 'x-checkpoint-delay', 'block-incremental',
>             'x-multifd-channels', 'x-multifd-page-count',
> -           'xbzrle-cache-size' ] }
> +           'xbzrle-cache-size', 'tcp-port' ] }
>  
>  ##
>  # @MigrateSetParameters:
> @@ -564,6 +567,10 @@
>  #                     needs to be a multiple of the target page size
>  #                     and a power of 2
>  #                     (Since 2.11)
> +#
> +# @tcp-port: Only used for tcp, to know what is the real port
> +#                     (Since 2.12)
> +#
>  # Since: 2.4
>  ##
>  # TODO either fuse back into MigrationParameters, or make
> @@ -582,7 +589,8 @@
>              '*block-incremental': 'bool',
>              '*x-multifd-channels': 'int',
>              '*x-multifd-page-count': 'int',
> -            '*xbzrle-cache-size': 'size' } }
> +            '*xbzrle-cache-size': 'size' ,
> +            '*tcp-port': 'uint16'} }
>  
>  ##
>  # @migrate-set-parameters:
> @@ -665,6 +673,10 @@
>  #                     needs to be a multiple of the target page size
>  #                     and a power of 2
>  #                     (Since 2.11)
> +#
> +# @tcp-port: Only used for tcp, to know what is the real port
> +#                     (Since 2.12)
> +#
>  # Since: 2.4
>  ##
>  { 'struct': 'MigrationParameters',
> @@ -681,7 +693,8 @@
>              '*block-incremental': 'bool' ,
>              '*x-multifd-channels': 'uint8',
>              '*x-multifd-page-count': 'uint32',
> -            '*xbzrle-cache-size': 'size' } }
> +            '*xbzrle-cache-size': 'size',
> +            '*tcp-port': 'uint16'} }
>  
>  ##
>  # @query-migrate-parameters:
> -- 
> 2.14.3
> 

-- 
Peter Xu