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

[Dr. David Alan Gilbert]

* Peter Xu (address@hidden) wrote:
> 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)

Same question; it makes me wonder if this field should actually go in
MigrationStats; the problem with that is it's currently only shows the
source side; even though at times people have suggested adding
destination side data to it.

Dave

> > +        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
--
Dr. David Alan Gilbert / address@hidden / Manchester, UK