qapi: Add feature flags to commands

Similarly to features for struct types introduce the feature flags also
for commands. This will allow notifying management layers of fixes and
compatible changes in the behaviour of a command which may not be
detectable any other way.

The changes were heavily inspired by commit 6a8c0b5102.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20191018081454.21369-3-armbru@redhat.com>
This commit is contained in:
Peter Krempa 2019-10-18 10:14:51 +02:00 committed by Markus Armbruster
parent 758f272b6d
commit 23394b4c39
8 changed files with 62 additions and 28 deletions

View File

@ -457,7 +457,8 @@ Syntax:
'*gen': false,
'*allow-oob': true,
'*allow-preconfig': true,
'*if': COND }
'*if': COND,
'*features': FEATURES }
Member 'command' names the command.
@ -640,9 +641,10 @@ change in the QMP syntax (usually by allowing values or operations
that previously resulted in an error). QMP clients may still need to
know whether the extension is available.
For this purpose, a list of features can be specified for a struct type.
This is exposed to the client as a list of string, where each string
signals that this build of QEMU shows a certain behaviour.
For this purpose, a list of features can be specified for a command or
struct type. This is exposed to the client as a list of strings,
where each string signals that this build of QEMU shows a certain
behaviour.
Each member of the 'features' array defines a feature. It can either
be { 'name': STRING, '*if': COND }, or STRING, which is shorthand for

View File

@ -266,13 +266,17 @@
# @allow-oob: whether the command allows out-of-band execution,
# defaults to false (Since: 2.12)
#
# @features: names of features associated with the command, in no particular
# order. (since 4.2)
#
# 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',
'*features': [ 'str' ] } }
##
# @SchemaInfoEvent:

View File

@ -277,7 +277,8 @@ void %(c_prefix)sqmp_init_marshal(QmpCommandList *cmds);
genc.add(gen_registry(self._regy.get_content(), self._prefix))
def visit_command(self, name, info, ifcond, arg_type, ret_type, gen,
success_response, boxed, allow_oob, allow_preconfig):
success_response, boxed, allow_oob, allow_preconfig,
features):
if not gen:
return
# FIXME: If T is a user-defined type, the user is responsible

View File

@ -249,12 +249,14 @@ class QAPISchemaGenDocVisitor(QAPISchemaVisitor):
body=texi_entity(doc, 'Members', ifcond)))
def visit_command(self, name, info, ifcond, arg_type, ret_type, gen,
success_response, boxed, allow_oob, allow_preconfig):
success_response, boxed, allow_oob, allow_preconfig,
features):
doc = self.cur_doc
if boxed:
body = texi_body(doc)
body += ('\n@b{Arguments:} the members of @code{%s}\n'
% arg_type.name)
body += texi_features(doc)
body += texi_sections(doc, ifcond)
else:
body = texi_entity(doc, 'Arguments', ifcond)

View File

@ -185,6 +185,22 @@ def normalize_features(features):
for f in features]
def check_features(features, info):
if features is None:
return
if not isinstance(features, list):
raise QAPISemError(info, "'features' must be an array")
for f in features:
source = "'features' member"
assert isinstance(f, dict)
check_keys(f, info, source, ['name'], ['if'])
check_name_is_str(f['name'], info, source)
source = "%s '%s'" % (source, f['name'])
check_name_str(f['name'], info, source)
check_if(f, info, source)
normalize_if(f)
def normalize_enum(expr):
if isinstance(expr['data'], list):
expr['data'] = [m if isinstance(m, dict) else {'name': m}
@ -217,23 +233,10 @@ def check_enum(expr, info):
def check_struct(expr, info):
name = expr['struct']
members = expr['data']
features = expr.get('features')
check_type(members, info, "'data'", allow_dict=name)
check_type(expr.get('base'), info, "'base'")
if features:
if not isinstance(features, list):
raise QAPISemError(info, "'features' must be an array")
for f in features:
source = "'features' member"
assert isinstance(f, dict)
check_keys(f, info, source, ['name'], ['if'])
check_name_is_str(f['name'], info, source)
source = "%s '%s'" % (source, f['name'])
check_name_str(f['name'], info, source)
check_if(f, info, source)
normalize_if(f)
check_features(expr.get('features'), info)
def check_union(expr, info):
@ -283,6 +286,7 @@ def check_command(expr, info):
raise QAPISemError(info, "'boxed': true requires 'data'")
check_type(args, info, "'data'", allow_dict=not boxed)
check_type(rets, info, "'returns'", allow_array=True)
check_features(expr.get('features'), info)
def check_event(expr, info):
@ -358,10 +362,11 @@ def check_exprs(exprs):
elif meta == 'command':
check_keys(expr, info, meta,
['command'],
['data', 'returns', 'boxed', 'if',
['data', 'returns', 'boxed', 'if', 'features',
'gen', 'success-response', 'allow-oob',
'allow-preconfig'])
normalize_members(expr.get('data'))
normalize_features(expr.get('features'))
check_command(expr, info)
elif meta == 'event':
check_keys(expr, info, meta,

View File

@ -211,13 +211,18 @@ const QLitObject %(c_name)s = %(c_string)s;
for m in variants.variants]}, ifcond)
def visit_command(self, name, info, ifcond, arg_type, ret_type, gen,
success_response, boxed, allow_oob, allow_preconfig):
success_response, boxed, allow_oob, allow_preconfig,
features):
arg_type = arg_type or self._schema.the_empty_object_type
ret_type = ret_type or self._schema.the_empty_object_type
obj = {'arg-type': self._use_type(arg_type),
'ret-type': self._use_type(ret_type)}
if allow_oob:
obj['allow-oob'] = allow_oob
if features:
obj['features'] = [(f.name, {'if': f.ifcond}) for f in features]
self._gen_qlit(name, 'command', obj, ifcond)
def visit_event(self, name, info, ifcond, arg_type, boxed):

View File

@ -110,7 +110,8 @@ class QAPISchemaVisitor(object):
pass
def visit_command(self, name, info, ifcond, arg_type, ret_type, gen,
success_response, boxed, allow_oob, allow_preconfig):
success_response, boxed, allow_oob, allow_preconfig,
features):
pass
def visit_event(self, name, info, ifcond, arg_type, boxed):
@ -659,10 +660,14 @@ class QAPISchemaCommand(QAPISchemaEntity):
meta = 'command'
def __init__(self, name, info, doc, ifcond, arg_type, ret_type,
gen, success_response, boxed, allow_oob, allow_preconfig):
gen, success_response, boxed, allow_oob, allow_preconfig,
features):
QAPISchemaEntity.__init__(self, name, info, doc, ifcond)
assert not arg_type or isinstance(arg_type, str)
assert not ret_type or isinstance(ret_type, str)
for f in features:
assert isinstance(f, QAPISchemaFeature)
f.set_defined_in(name)
self._arg_type_name = arg_type
self.arg_type = None
self._ret_type_name = ret_type
@ -672,6 +677,7 @@ class QAPISchemaCommand(QAPISchemaEntity):
self.boxed = boxed
self.allow_oob = allow_oob
self.allow_preconfig = allow_preconfig
self.features = features
def check(self, schema):
QAPISchemaEntity.check(self, schema)
@ -701,13 +707,19 @@ class QAPISchemaCommand(QAPISchemaEntity):
"command's 'returns' cannot take %s"
% self.ret_type.describe())
# Features are in a name space separate from members
seen = {}
for f in self.features:
f.check_clash(self.info, seen)
def visit(self, visitor):
QAPISchemaEntity.visit(self, visitor)
visitor.visit_command(self.name, self.info, self.ifcond,
self.arg_type, self.ret_type,
self.gen, self.success_response,
self.boxed, self.allow_oob,
self.allow_preconfig)
self.allow_preconfig,
self.features)
class QAPISchemaEvent(QAPISchemaEntity):
@ -984,6 +996,7 @@ class QAPISchema(object):
allow_oob = expr.get('allow-oob', False)
allow_preconfig = expr.get('allow-preconfig', False)
ifcond = expr.get('if')
features = expr.get('features', [])
if isinstance(data, OrderedDict):
data = self._make_implicit_object_type(
name, info, doc, ifcond, 'arg', self._make_members(data, info))
@ -992,7 +1005,8 @@ class QAPISchema(object):
rets = self._make_array_type(rets[0], info)
self._def_entity(QAPISchemaCommand(name, info, doc, ifcond, data, rets,
gen, success_response,
boxed, allow_oob, allow_preconfig))
boxed, allow_oob, allow_preconfig,
self._make_features(features, info)))
def _def_event(self, expr, info, doc):
name = expr['event']

View File

@ -72,7 +72,8 @@ class QAPISchemaTestVisitor(QAPISchemaVisitor):
self._print_if(ifcond)
def visit_command(self, name, info, ifcond, arg_type, ret_type, gen,
success_response, boxed, allow_oob, allow_preconfig):
success_response, boxed, allow_oob, allow_preconfig,
features):
print('command %s %s -> %s'
% (name, arg_type and arg_type.name,
ret_type and ret_type.name))