[Qemu-devel] [PATCH for-2.13 v5 05/11] qapi: introduce new cmd option "allowed-in-preconfig"

[Igor Mammedov <imammedo@redhat.com>]

New option will be used to allow commands, which are prepared/need
to run, during preconfig state. Other commands that should be able
to run in preconfig state, should be ameded to not expect machine
in initialized state or deal with it.

For compatibility reasons, commands that don't use new flag
'allowed-in-preconfig' explicitly are not permitted to run in
preconfig state but allowed in all other states like they used
to be.

Within this patch allow following commands in preconfig state:
   qmp_capabilities
   query-qmp-schema
   query-commands
   query-command-line-options
   query-status
   cont
to allow qmp connection, basic introspection and moving to the next
state.

PS:
set-numa-node and query-hotpluggable-cpus will be enabled later in
a separate patch.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
---
v5:
  * allow query-command-line-options in preconfig state
  * rebase on top of OOB changes that's now in master
  * spelling/wording fixups
  * make sure that allowed-in-preconfig could be set only to True
  * move out QCO_ALLOWED_IN_PRECONFIG check in do_qmp_dispatch() to
    earlier 'cli: add -preconfig option' patch
v4:
  * replaces complex "universal" approach
     "[PATCH v3 5/9] QAPI: allow to specify valid runstates  per command"
    with a simpler new command flag "allowed-in-preconfig".
    (Eric Blake <eblake@redhat.com>)
---
 docs/devel/qapi-code-gen.txt   | 10 +++++++++-
 monitor.c                      |  5 +++--
 qapi/introspect.json           |  5 ++++-
 qapi/misc.json                 | 11 +++++++----
 qapi/run-state.json            |  3 ++-
 scripts/qapi/commands.py       | 12 ++++++++----
 scripts/qapi/common.py         | 19 ++++++++++++-------
 scripts/qapi/doc.py            |  4 ++--
 scripts/qapi/introspect.py     |  7 ++++---
 tests/qapi-schema/test-qapi.py |  4 ++--
 10 files changed, 53 insertions(+), 27 deletions(-)

diff --git a/docs/devel/qapi-code-gen.txt b/docs/devel/qapi-code-gen.txt
index a569d24..31c4646 100644
--- a/docs/devel/qapi-code-gen.txt
+++ b/docs/devel/qapi-code-gen.txt
@@ -559,7 +559,7 @@ following example objects:
 Usage: { 'command': STRING, '*data': COMPLEX-TYPE-NAME-OR-DICT,
          '*returns': TYPE-NAME, '*boxed': true,
          '*gen': false, '*success-response': false,
-         '*allow-oob': true }
+         '*allow-oob': true, '*allowed-in-preconfig': true }
 
 Commands are defined by using a dictionary containing several members,
 where three members are most common.  The 'command' member is a
@@ -683,6 +683,14 @@ OOB command handlers must satisfy the following conditions:
 
 If in doubt, do not implement OOB execution support.
 
+A command may use optional 'allowed-in-preconfig' key to permit
+its execution at early runtime configuration stage (preconfig runstate).
+If not specified then a command defaults to 'allowed-in-preconfig: false'.
+
+An example of declaring preconfig enabled command:
+ { 'command': 'qmp_capabilities',
+   'allowed-in-preconfig': true }
+
 === Events ===
 
 Usage: { 'event': STRING, '*data': COMPLEX-TYPE-NAME-OR-DICT,
diff --git a/monitor.c b/monitor.c
index fd1e7c8..18a47c9 100644
--- a/monitor.c
+++ b/monitor.c
@@ -1183,7 +1183,7 @@ static void monitor_init_qmp_commands(void)
 
     qmp_register_command(&qmp_commands, "query-qmp-schema",
                          qmp_query_qmp_schema,
-                         QCO_NO_OPTIONS);
+                         QCO_ALLOWED_IN_PRECONFIG);
     qmp_register_command(&qmp_commands, "device_add", qmp_device_add,
                          QCO_NO_OPTIONS);
     qmp_register_command(&qmp_commands, "netdev_add", qmp_netdev_add,
@@ -1193,7 +1193,8 @@ static void monitor_init_qmp_commands(void)
 
     QTAILQ_INIT(&qmp_cap_negotiation_commands);
     qmp_register_command(&qmp_cap_negotiation_commands, "qmp_capabilities",
-                         qmp_marshal_qmp_capabilities, QCO_NO_OPTIONS);
+                         qmp_marshal_qmp_capabilities,
+                         QCO_ALLOWED_IN_PRECONFIG);
 }
 
 static bool qmp_cap_enabled(Monitor *mon, QMPCapability cap)
diff --git a/qapi/introspect.json b/qapi/introspect.json
index c7f67b7..8036154 100644
--- a/qapi/introspect.json
+++ b/qapi/introspect.json
@@ -262,13 +262,16 @@
 # @allow-oob: whether the command allows out-of-band execution.
 #             (Since: 2.12)
 #
+# @allowed-in-preconfig: command can be executed in preconfig runstate,
+#                        default: 'false' (Since 2.13)
+#
 # TODO: @success-response (currently irrelevant, because it's QGA, not QMP)
 #
 # Since: 2.5
 ##
 { 'struct': 'SchemaInfoCommand',
   'data': { 'arg-type': 'str', 'ret-type': 'str',
-            'allow-oob': 'bool' } }
+            'allow-oob': 'bool', 'allowed-in-preconfig': 'bool' } }
 
 ##
 # @SchemaInfoEvent:
diff --git a/qapi/misc.json b/qapi/misc.json
index 5636f4a..579900f 100644
--- a/qapi/misc.json
+++ b/qapi/misc.json
@@ -35,7 +35,8 @@
 #
 ##
 { 'command': 'qmp_capabilities',
-  'data': { '*enable': [ 'QMPCapability' ] } }
+  'data': { '*enable': [ 'QMPCapability' ] },
+  'allowed-in-preconfig': true }
 
 ##
 # @QMPCapability:
@@ -153,7 +154,8 @@
 # Note: This example has been shortened as the real response is too long.
 #
 ##
-{ 'command': 'query-commands', 'returns': ['CommandInfo'] }
+{ 'command': 'query-commands', 'returns': ['CommandInfo'],
+  'allowed-in-preconfig': true }
 
 ##
 # @LostTickPolicy:
@@ -1206,7 +1208,7 @@
 # <- { "return": {} }
 #
 ##
-{ 'command': 'cont' }
+{ 'command': 'cont', 'allowed-in-preconfig': true }
 
 ##
 # @system_wakeup:
@@ -2614,7 +2616,8 @@
 #
 ##
 {'command': 'query-command-line-options', 'data': { '*option': 'str' },
- 'returns': ['CommandLineOptionInfo'] }
+ 'returns': ['CommandLineOptionInfo'],
+ 'allowed-in-preconfig': true }
 
 ##
 # @X86CPURegister32:
diff --git a/qapi/run-state.json b/qapi/run-state.json
index 9694a9f..d6ed5d8 100644
--- a/qapi/run-state.json
+++ b/qapi/run-state.json
@@ -94,7 +94,8 @@
 #                  "status": "running" } }
 #
 ##
-{ 'command': 'query-status', 'returns': 'StatusInfo' }
+{ 'command': 'query-status', 'returns': 'StatusInfo',
+  'allowed-in-preconfig': true }
 
 ##
 # @SHUTDOWN:
diff --git a/scripts/qapi/commands.py b/scripts/qapi/commands.py
index 0c5da3a..9975d95 100644
--- a/scripts/qapi/commands.py
+++ b/scripts/qapi/commands.py
@@ -193,13 +193,16 @@ out:
     return ret
 
 
-def gen_register_command(name, success_response, allow_oob):
+def gen_register_command(name, success_response, allow_oob,
+                         allowed_in_preconfig):
     options = []
 
     if not success_response:
         options += ['QCO_NO_SUCCESS_RESP']
     if allow_oob:
         options += ['QCO_ALLOW_OOB']
+    if allowed_in_preconfig:
+        options += ['QCO_ALLOWED_IN_PRECONFIG']
 
     if not options:
         options = ['QCO_NO_OPTIONS']
@@ -275,8 +278,8 @@ void %(c_prefix)sqmp_init_marshal(QmpCommandList *cmds);
                        c_prefix=c_name(self._prefix, protect=False)))
         genc.add(gen_registry(self._regy, self._prefix))
 
-    def visit_command(self, name, info, arg_type, ret_type,
-                      gen, success_response, boxed, allow_oob):
+    def visit_command(self, name, info, arg_type, ret_type, gen,
+                      success_response, boxed, allow_oob, allowed_in_preconfig):
         if not gen:
             return
         self._genh.add(gen_command_decl(name, arg_type, boxed, ret_type))
@@ -285,7 +288,8 @@ void %(c_prefix)sqmp_init_marshal(QmpCommandList *cmds);
             self._genc.add(gen_marshal_output(ret_type))
         self._genh.add(gen_marshal_decl(name))
         self._genc.add(gen_marshal(name, arg_type, boxed, ret_type))
-        self._regy += gen_register_command(name, success_response, allow_oob)
+        self._regy += gen_register_command(name, success_response, allow_oob,
+                                           allowed_in_preconfig)
 
 
 def gen_commands(schema, output_dir, prefix):
diff --git a/scripts/qapi/common.py b/scripts/qapi/common.py
index 3e14bc4..87273a2 100644
--- a/scripts/qapi/common.py
+++ b/scripts/qapi/common.py
@@ -872,7 +872,8 @@ def check_keys(expr_elem, meta, required, optional=[]):
             raise QAPISemError(info,
                                "'%s' of %s '%s' should only use false value"
                                % (key, meta, name))
-        if (key == 'boxed' or key == 'allow-oob') and value is not True:
+        if (key == 'boxed' or key == 'allow-oob' or
+            key == 'allowed-in-preconfig') and value is not True:
             raise QAPISemError(info,
                                "'%s' of %s '%s' should only use true value"
                                % (key, meta, name))
@@ -922,7 +923,7 @@ def check_exprs(exprs):
             meta = 'command'
             check_keys(expr_elem, 'command', [],
                        ['data', 'returns', 'gen', 'success-response',
-                        'boxed', 'allow-oob'])
+                        'boxed', 'allow-oob', 'allowed-in-preconfig'])
         elif 'event' in expr:
             meta = 'event'
             check_keys(expr_elem, 'event', [], ['data', 'boxed'])
@@ -1044,8 +1045,8 @@ class QAPISchemaVisitor(object):
     def visit_alternate_type(self, name, info, variants):
         pass
 
-    def visit_command(self, name, info, arg_type, ret_type,
-                      gen, success_response, boxed, allow_oob):
+    def visit_command(self, name, info, arg_type, ret_type, gen,
+                      success_response, boxed, allow_oob, allowed_in_preconfig):
         pass
 
     def visit_event(self, name, info, arg_type, boxed):
@@ -1422,7 +1423,7 @@ class QAPISchemaAlternateType(QAPISchemaType):
 
 class QAPISchemaCommand(QAPISchemaEntity):
     def __init__(self, name, info, doc, arg_type, ret_type,
-                 gen, success_response, boxed, allow_oob):
+                 gen, success_response, boxed, allow_oob, allowed_in_preconfig):
         QAPISchemaEntity.__init__(self, name, info, doc)
         assert not arg_type or isinstance(arg_type, str)
         assert not ret_type or isinstance(ret_type, str)
@@ -1434,6 +1435,7 @@ class QAPISchemaCommand(QAPISchemaEntity):
         self.success_response = success_response
         self.boxed = boxed
         self.allow_oob = allow_oob
+        self.allowed_in_preconfig = allowed_in_preconfig
 
     def check(self, schema):
         if self._arg_type_name:
@@ -1458,7 +1460,8 @@ class QAPISchemaCommand(QAPISchemaEntity):
         visitor.visit_command(self.name, self.info,
                               self.arg_type, self.ret_type,
                               self.gen, self.success_response,
-                              self.boxed, self.allow_oob)
+                              self.boxed, self.allow_oob,
+                              self.allowed_in_preconfig)
 
 
 class QAPISchemaEvent(QAPISchemaEntity):
@@ -1678,6 +1681,7 @@ class QAPISchema(object):
         success_response = expr.get('success-response', True)
         boxed = expr.get('boxed', False)
         allow_oob = expr.get('allow-oob', False)
+        allowed_in_preconfig = expr.get('allowed-in-preconfig', False)
         if isinstance(data, OrderedDict):
             data = self._make_implicit_object_type(
                 name, info, doc, 'arg', self._make_members(data, info))
@@ -1686,7 +1690,8 @@ class QAPISchema(object):
             rets = self._make_array_type(rets[0], info)
         self._def_entity(QAPISchemaCommand(name, info, doc, data, rets,
                                            gen, success_response,
-                                           boxed, allow_oob))
+                                           boxed, allow_oob,
+                                           allowed_in_preconfig))
 
     def _def_event(self, expr, info, doc):
         name = expr['event']
diff --git a/scripts/qapi/doc.py b/scripts/qapi/doc.py
index 9b312b2..cb6f2e1 100644
--- a/scripts/qapi/doc.py
+++ b/scripts/qapi/doc.py
@@ -226,8 +226,8 @@ class QAPISchemaGenDocVisitor(qapi.common.QAPISchemaVisitor):
                                name=doc.symbol,
                                body=texi_entity(doc, 'Members')))
 
-    def visit_command(self, name, info, arg_type, ret_type,
-                      gen, success_response, boxed, allow_oob):
+    def visit_command(self, name, info, arg_type, ret_type, gen,
+                      success_response, boxed, allow_oob, allowed_in_preconfig):
         doc = self.cur_doc
         if boxed:
             body = texi_body(doc)
diff --git a/scripts/qapi/introspect.py b/scripts/qapi/introspect.py
index f9e67e8..5246be1 100644
--- a/scripts/qapi/introspect.py
+++ b/scripts/qapi/introspect.py
@@ -171,14 +171,15 @@ const QLitObject %(c_name)s = %(c_string)s;
                        {'members': [{'type': self._use_type(m.type)}
                                     for m in variants.variants]})
 
-    def visit_command(self, name, info, arg_type, ret_type,
-                      gen, success_response, boxed, allow_oob):
+    def visit_command(self, name, info, arg_type, ret_type, gen,
+                      success_response, boxed, allow_oob, allowed_in_preconfig):
         arg_type = arg_type or self._schema.the_empty_object_type
         ret_type = ret_type or self._schema.the_empty_object_type
         self._gen_qlit(name, 'command',
                        {'arg-type': self._use_type(arg_type),
                         'ret-type': self._use_type(ret_type),
-                        'allow-oob': allow_oob})
+                        'allow-oob': allow_oob,
+                        'allowed-in-preconfig': allowed_in_preconfig})
 
     def visit_event(self, name, info, arg_type, boxed):
         arg_type = arg_type or self._schema.the_empty_object_type
diff --git a/tests/qapi-schema/test-qapi.py b/tests/qapi-schema/test-qapi.py
index c1a144b..73d2c77 100644
--- a/tests/qapi-schema/test-qapi.py
+++ b/tests/qapi-schema/test-qapi.py
@@ -41,8 +41,8 @@ class QAPISchemaTestVisitor(QAPISchemaVisitor):
         print('alternate %s' % name)
         self._print_variants(variants)
 
-    def visit_command(self, name, info, arg_type, ret_type,
-                      gen, success_response, boxed, allow_oob):
+    def visit_command(self, name, info, arg_type, ret_type, gen,
+                      success_response, boxed, allow_oob, allowed_in_preconfig):
         print('command %s %s -> %s' % \
               (name, arg_type and arg_type.name, ret_type and ret_type.name))
         print('   gen=%s success_response=%s boxed=%s oob=%s' % \
-- 
2.7.4