[17/26] qapi: add conditions to SPICE type/commands/events on the schema

Add #if defined(CONFIG_SPICE) in generated code, and adjust the
qmp/hmp code accordingly.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
---
 qapi-schema.json | 28 ++++++++++++++++++----------
 qapi/event.json  | 12 ++++++++----
 monitor.c        |  3 ---
 qmp.c            | 16 ----------------
 4 files changed, 26 insertions(+), 33 deletions(-)

Copying our resident SPICE maintainer Gerd.

Marc-André Lureau <marcandre.lureau@redhat.com> writes:

> Add #if defined(CONFIG_SPICE) in generated code, and adjust the
> qmp/hmp code accordingly.
>
> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> ---
>  qapi-schema.json | 28 ++++++++++++++++++----------
>  qapi/event.json  | 12 ++++++++----
>  monitor.c        |  3 ---
>  qmp.c            | 16 ----------------
>  4 files changed, 26 insertions(+), 33 deletions(-)
>
> diff --git a/qapi-schema.json b/qapi-schema.json
> index 829c66f9eb..bcee3157b0 100644
> --- a/qapi-schema.json
> +++ b/qapi-schema.json
> @@ -1878,7 +1878,8 @@
>  { 'struct': 'SpiceBasicInfo',
>    'data': { 'host': 'str',
>              'port': 'str',
> -            'family': 'NetworkAddressFamily' } }
> +            'family': 'NetworkAddressFamily' },
> +  'if': 'defined(CONFIG_SPICE)' }
>  
>  ##
>  # @SpiceServerInfo:
> @@ -1891,7 +1892,8 @@
>  ##
>  { 'struct': 'SpiceServerInfo',
>    'base': 'SpiceBasicInfo',
> -  'data': { '*auth': 'str' } }
> +  'data': { '*auth': 'str' },
> +  'if': 'defined(CONFIG_SPICE)' }
>  
>  ##
>  # @SpiceChannel:
> @@ -1916,7 +1918,8 @@
>  { 'struct': 'SpiceChannel',
>    'base': 'SpiceBasicInfo',
>    'data': {'connection-id': 'int', 'channel-type': 'int', 'channel-id': 'int',
> -           'tls': 'bool'} }
> +           'tls': 'bool'},
> +  'if': 'defined(CONFIG_SPICE)' }
>  
>  ##
>  # @SpiceQueryMouseMode:
> @@ -1935,7 +1938,8 @@
>  # Since: 1.1
>  ##
>  { 'enum': 'SpiceQueryMouseMode',
> -  'data': [ 'client', 'server', 'unknown' ] }
> +  'data': [ 'client', 'server', 'unknown' ],
> +  'if': 'defined(CONFIG_SPICE)' }
>  
>  ##
>  # @SpiceInfo:
> @@ -1972,7 +1976,8 @@
>  { 'struct': 'SpiceInfo',
>    'data': {'enabled': 'bool', 'migrated': 'bool', '*host': 'str', '*port': 'int',
>             '*tls-port': 'int', '*auth': 'str', '*compiled-version': 'str',
> -           'mouse-mode': 'SpiceQueryMouseMode', '*channels': ['SpiceChannel']} }
> +           'mouse-mode': 'SpiceQueryMouseMode', '*channels': ['SpiceChannel']},
> +  'if': 'defined(CONFIG_SPICE)' }
>  
>  ##
>  # @query-spice:
> @@ -2017,7 +2022,8 @@
>  #    }
>  #
>  ##
> -{ 'command': 'query-spice', 'returns': 'SpiceInfo' }
> +{ 'command': 'query-spice', 'returns': 'SpiceInfo',
> +  'if': 'defined(CONFIG_SPICE)' }
>  
>  ##
>  # @BalloonInfo:
> @@ -5067,7 +5073,8 @@
>  # Since: 1.5
>  ##
>  { 'struct': 'ChardevSpiceChannel', 'data': { 'type'  : 'str' },
> -  'base': 'ChardevCommon' }
> +  'base': 'ChardevCommon',
> +  'if': 'defined(CONFIG_SPICE)' }
>  
>  ##
>  # @ChardevSpicePort:
> @@ -5079,7 +5086,8 @@
>  # Since: 1.5
>  ##
>  { 'struct': 'ChardevSpicePort', 'data': { 'fqdn'  : 'str' },
> -  'base': 'ChardevCommon' }
> +  'base': 'ChardevCommon',
> +  'if': 'defined(CONFIG_SPICE)' }
>  
>  ##
>  # @ChardevVC:
> @@ -5133,8 +5141,8 @@
>                                         'testdev': 'ChardevCommon',
>                                         'stdio'  : 'ChardevStdio',
>                                         'console': 'ChardevCommon',
> -                                       'spicevmc' : 'ChardevSpiceChannel',
> -                                       'spiceport' : 'ChardevSpicePort',
> +                                       'spicevmc' : { 'type': 'ChardevSpiceChannel', 'if': 'defined(CONFIG_SPICE)' },
> +                                       'spiceport' : { 'type': 'ChardevSpicePort', 'if': 'defined(CONFIG_SPICE)' },
>                                         'vc'     : 'ChardevVC',
>                                         'ringbuf': 'ChardevRingbuf',
>                                         # next one is just for compatibility
> diff --git a/qapi/event.json b/qapi/event.json
> index c8b8e9f384..ff59551914 100644
> --- a/qapi/event.json
> +++ b/qapi/event.json
> @@ -344,7 +344,8 @@
>  ##
>  { 'event': 'SPICE_CONNECTED',
>    'data': { 'server': 'SpiceBasicInfo',
> -            'client': 'SpiceBasicInfo' } }
> +            'client': 'SpiceBasicInfo' },
> +  'if': 'defined(CONFIG_SPICE)' }
>  
>  ##
>  # @SPICE_INITIALIZED:
> @@ -372,7 +373,8 @@
>  ##
>  { 'event': 'SPICE_INITIALIZED',
>    'data': { 'server': 'SpiceServerInfo',
> -            'client': 'SpiceChannel' } }
> +            'client': 'SpiceChannel' },
> +  'if': 'defined(CONFIG_SPICE)' }
>  
>  ##
>  # @SPICE_DISCONNECTED:
> @@ -397,7 +399,8 @@
>  ##
>  { 'event': 'SPICE_DISCONNECTED',
>    'data': { 'server': 'SpiceBasicInfo',
> -            'client': 'SpiceBasicInfo' } }
> +            'client': 'SpiceBasicInfo' },
> +  'if': 'defined(CONFIG_SPICE)' }
>  
>  ##
>  # @SPICE_MIGRATE_COMPLETED:
> @@ -412,7 +415,8 @@
>  #      "event": "SPICE_MIGRATE_COMPLETED" }
>  #
>  ##
> -{ 'event': 'SPICE_MIGRATE_COMPLETED' }
> +{ 'event': 'SPICE_MIGRATE_COMPLETED',
> +  'if': 'defined(CONFIG_SPICE)' }
>  
>  ##
>  # @MIGRATION:
> diff --git a/monitor.c b/monitor.c
> index a1773d5bc7..4bf6a3ea2e 100644
> --- a/monitor.c
> +++ b/monitor.c
> @@ -970,9 +970,6 @@ static void qmp_query_qmp_schema(QDict *qdict, QObject **ret_data,
>   */
>  static void qmp_unregister_commands_hack(void)
>  {
> -#ifndef CONFIG_SPICE
> -    qmp_unregister_command(&qmp_commands, "query-spice");
> -#endif
>  #ifndef CONFIG_REPLICATION
>      qmp_unregister_command(&qmp_commands, "xen-set-replication");
>      qmp_unregister_command(&qmp_commands, "query-xen-replication-status");
> diff --git a/qmp.c b/qmp.c
> index 2c90dacb56..90816ba283 100644
> --- a/qmp.c
> +++ b/qmp.c
> @@ -130,22 +130,6 @@ void qmp_cpu_add(int64_t id, Error **errp)
>      }
>  }
>  
> -#ifndef CONFIG_SPICE
> -/*
> - * qmp-commands.hx ensures that QMP command query-spice exists only
> - * #ifdef CONFIG_SPICE.  Necessary for an accurate query-commands
> - * result.  However, the QAPI schema is blissfully unaware of that,
> - * and the QAPI code generator happily generates a dead
> - * qmp_marshal_query_spice() that calls qmp_query_spice().  Provide it
> - * one, or else linking fails.  FIXME Educate the QAPI schema on
> - * CONFIG_SPICE.
> - */
> -SpiceInfo *qmp_query_spice(Error **errp)
> -{
> -    abort();
> -};
> -#endif
> -
>  void qmp_cont(Error **errp)
>  {
>      BlockBackend *blk;

Same drill as for PATCH 16.

Commands you make conditional:

* query-spice

  Before the patch, we first register the unconditionally command in
  generated code (requires a stub), then conditionally unregister in
  qmp_unregister_commands_hack().

  Afterwards, we register only when CONFIG_SPICE.  The command fails
  exactly the same, with CommandNotFound.

  Improvement, because now query-qmp-schema is accurate, and we're one
  step close to killing qmp_unregister_commands_hack().

Command arguments you make conditional:

* chardev-add, chardev-change variants spicevmc, spiceport

  Before the patch, "spicevmc" and "spiceport" are valid values of
  "type", but char_get_class() can't map them to a QOM type name, and
  fails with "'FOO' is not a valid char driver name".

  Afterwards, they aren't valid values, and input_type_enum() rejects
  them with "Invalid parameter 'FOO'".  That error message could use
  improvement, but that's not this patch's problem.

Events you make conditional:

* SPICE_CONNECTED, SPICE_INITIALIZED, SPICE_DISCONNECTED,
  SPICE_MIGRATE_COMPLETED

Check for completeness by reviewing the case insensitive occurrences of
SPICE in the schema not covered by your patch:

* add_client

  Same rationale as for VNC (see my review of PATCH 16).  Good.

* query-chardev-backends

  No conditional, because ChardevBackendInfo member @name is 'str'.  I
  think it should be an enum instead, and then we'd need to make some
  values conditional.  Not this patch's problem.

* client_migrate_info

  Similar to set_password and expire_password, this is generic in
  theory, documented for just "remote display", and implemented just for
  SPICE, with a stub for !CONFIG_SPICE.  Okay for the same reasons
  set_password and expire_password are okay.

* set_password, expire_password

  Same rationale as for VNC (see my review of PATCH 16).  Okay.

Some of this analysis should perhaps be worked into the commit message.

Markus Armbruster <armbru@redhat.com> writes:

[...]
> Check for completeness by reviewing the case insensitive occurrences of
> SPICE in the schema not covered by your patch:
>
> * add_client
>
>   Same rationale as for VNC (see my review of PATCH 16).  Good.

Hmm, there's a difference to VNC, in qmp_add_client():

    if (strcmp(protocol, "spice") == 0) {
        if (!qemu_using_spice(errp)) {
            close(fd);
            return;
        }
        skipauth = has_skipauth ? skipauth : false;
        tls = has_tls ? tls : false;
        if (qemu_spice_display_add_client(fd, skipauth, tls) < 0) {
            error_setg(errp, "spice failed to add client");
            close(fd);
        }
        return;
#ifdef CONFIG_VNC
    } else if (strcmp(protocol, "vnc") == 0) {
        skipauth = has_skipauth ? skipauth : false;
        vnc_display_add_client(NULL, fd, skipauth);
        return;
#endif
    } else if ((s = qemu_chr_find(protocol)) != NULL) {
        if (qemu_chr_add_client(s, fd) < 0) {
            error_setg(errp, "failed to add client");
            close(fd);
            return;
        }
        return;
    }

    error_setg(errp, "protocol '%s' is invalid", protocol);
    close(fd);

Observe:

* Protocol "spice" is always recognized.  Without CONFIG_SPICE,
  using_spice is always false, and the command fails with
  qemu_using_spice()'s error "SPICE is not in use".

* Protocol "vnc" is only recognized with CONFIG_VNC.  Without, it's
  rejected with "protocol 'vnc' is invalid".

* If you name your character device "spice" or "vnc", you can't use it
  with add_client.  This is a design flaw.

  Except you can use one named "vnc" when !CONFIG_VNC.

  I'm afraid the command needs to be replaced.  Not in this series, of
  course.

[...]