This patch adds a new 'coroutine' flag to QMP command definitions that tells the QMP dispatcher that the command handler is safe to be run in a coroutine.
The documentation of the new flag pretends that this flag is already used as intended, which it isn't yet after this patch. We'll implement this in another patch in this series. Signed-off-by: Kevin Wolf <kw...@redhat.com> Reviewed-by: Marc-André Lureau <marcandre.lur...@redhat.com> Reviewed-by: Markus Armbruster <arm...@redhat.com> --- docs/devel/qapi-code-gen.txt | 11 +++++++++++ include/qapi/qmp/dispatch.h | 1 + tests/test-qmp-cmds.c | 4 ++++ scripts/qapi/commands.py | 10 +++++++--- scripts/qapi/doc.py | 2 +- scripts/qapi/expr.py | 10 ++++++++-- scripts/qapi/introspect.py | 2 +- scripts/qapi/schema.py | 9 ++++++--- tests/qapi-schema/test-qapi.py | 7 ++++--- tests/Makefile.include | 1 + tests/qapi-schema/oob-coroutine.err | 2 ++ tests/qapi-schema/oob-coroutine.json | 2 ++ tests/qapi-schema/oob-coroutine.out | 0 tests/qapi-schema/qapi-schema-test.json | 1 + tests/qapi-schema/qapi-schema-test.out | 2 ++ 15 files changed, 51 insertions(+), 13 deletions(-) create mode 100644 tests/qapi-schema/oob-coroutine.err create mode 100644 tests/qapi-schema/oob-coroutine.json create mode 100644 tests/qapi-schema/oob-coroutine.out diff --git a/docs/devel/qapi-code-gen.txt b/docs/devel/qapi-code-gen.txt index 59d6973e1e..df01bd852b 100644 --- a/docs/devel/qapi-code-gen.txt +++ b/docs/devel/qapi-code-gen.txt @@ -457,6 +457,7 @@ Syntax: '*gen': false, '*allow-oob': true, '*allow-preconfig': true, + '*coroutine': true, '*if': COND, '*features': FEATURES } @@ -581,6 +582,16 @@ before the machine is built. It defaults to false. For example: QMP is available before the machine is built only when QEMU was started with --preconfig. +Member 'coroutine' tells the QMP dispatcher whether the command handler +is safe to be run in a coroutine. It defaults to false. If it is true, +the command handler is called from coroutine context and may yield while +waiting for an external event (such as I/O completion) in order to avoid +blocking the guest and other background operations. + +It is an error to specify both 'coroutine': true and 'allow-oob': true +for a command. (We don't currently have a use case for both together and +without a use case, it's not entirely clear what the semantics should be.) + The optional 'if' member specifies a conditional. See "Configuring the schema" below for more on this. diff --git a/include/qapi/qmp/dispatch.h b/include/qapi/qmp/dispatch.h index 9aa426a398..d6ce9efc8e 100644 --- a/include/qapi/qmp/dispatch.h +++ b/include/qapi/qmp/dispatch.h @@ -24,6 +24,7 @@ typedef enum QmpCommandOptions QCO_NO_SUCCESS_RESP = (1U << 0), QCO_ALLOW_OOB = (1U << 1), QCO_ALLOW_PRECONFIG = (1U << 2), + QCO_COROUTINE = (1U << 3), } QmpCommandOptions; typedef struct QmpCommand diff --git a/tests/test-qmp-cmds.c b/tests/test-qmp-cmds.c index 79507d9e54..6359cc28c7 100644 --- a/tests/test-qmp-cmds.c +++ b/tests/test-qmp-cmds.c @@ -35,6 +35,10 @@ void qmp_cmd_success_response(Error **errp) { } +void qmp_coroutine_cmd(Error **errp) +{ +} + Empty2 *qmp_user_def_cmd0(Error **errp) { return g_new0(Empty2, 1); diff --git a/scripts/qapi/commands.py b/scripts/qapi/commands.py index afa55b055c..f2f2f8948d 100644 --- a/scripts/qapi/commands.py +++ b/scripts/qapi/commands.py @@ -194,7 +194,8 @@ out: return ret -def gen_register_command(name, success_response, allow_oob, allow_preconfig): +def gen_register_command(name, success_response, allow_oob, allow_preconfig, + coroutine): options = [] if not success_response: @@ -203,6 +204,8 @@ def gen_register_command(name, success_response, allow_oob, allow_preconfig): options += ['QCO_ALLOW_OOB'] if allow_preconfig: options += ['QCO_ALLOW_PRECONFIG'] + if coroutine: + options += ['QCO_COROUTINE'] if not options: options = ['QCO_NO_OPTIONS'] @@ -285,7 +288,7 @@ void %(c_prefix)sqmp_init_marshal(QmpCommandList *cmds); def visit_command(self, name, info, ifcond, arg_type, ret_type, gen, success_response, boxed, allow_oob, allow_preconfig, - features): + coroutine, features): if not gen: return # FIXME: If T is a user-defined type, the user is responsible @@ -303,7 +306,8 @@ void %(c_prefix)sqmp_init_marshal(QmpCommandList *cmds); self._genh.add(gen_marshal_decl(name)) self._genc.add(gen_marshal(name, arg_type, boxed, ret_type)) self._regy.add(gen_register_command(name, success_response, - allow_oob, allow_preconfig)) + allow_oob, allow_preconfig, + coroutine)) def gen_commands(schema, output_dir, prefix): diff --git a/scripts/qapi/doc.py b/scripts/qapi/doc.py index 1787a53d91..69f971e427 100644 --- a/scripts/qapi/doc.py +++ b/scripts/qapi/doc.py @@ -264,7 +264,7 @@ class QAPISchemaGenDocVisitor(QAPISchemaVisitor): def visit_command(self, name, info, ifcond, arg_type, ret_type, gen, success_response, boxed, allow_oob, allow_preconfig, - features): + coroutine, features): doc = self.cur_doc self._gen.add(texi_msg('Command', doc, ifcond, texi_arguments(doc, diff --git a/scripts/qapi/expr.py b/scripts/qapi/expr.py index d7a289eded..95cc006cae 100644 --- a/scripts/qapi/expr.py +++ b/scripts/qapi/expr.py @@ -89,10 +89,16 @@ def check_flags(expr, info): if key in expr and expr[key] is not False: raise QAPISemError( info, "flag '%s' may only use false value" % key) - for key in ['boxed', 'allow-oob', 'allow-preconfig']: + for key in ['boxed', 'allow-oob', 'allow-preconfig', 'coroutine']: if key in expr and expr[key] is not True: raise QAPISemError( info, "flag '%s' may only use true value" % key) + if 'allow-oob' in expr and 'coroutine' in expr: + # This is not necessarily a fundamental incompatibility, but we don't + # have a use case and the desired semantics isn't obvious. The simplest + # solution is to forbid it until we get a use case for it. + raise QAPISemError(info, "flags 'allow-oob' and 'coroutine' " + "are incompatible") def check_if(expr, info, source): @@ -344,7 +350,7 @@ def check_exprs(exprs): ['command'], ['data', 'returns', 'boxed', 'if', 'features', 'gen', 'success-response', 'allow-oob', - 'allow-preconfig']) + 'allow-preconfig', 'coroutine']) normalize_members(expr.get('data')) check_command(expr, info) elif meta == 'event': diff --git a/scripts/qapi/introspect.py b/scripts/qapi/introspect.py index b3a463dd8b..8a296a69d6 100644 --- a/scripts/qapi/introspect.py +++ b/scripts/qapi/introspect.py @@ -212,7 +212,7 @@ const QLitObject %(c_name)s = %(c_string)s; def visit_command(self, name, info, ifcond, arg_type, ret_type, gen, success_response, boxed, allow_oob, allow_preconfig, - features): + coroutine, 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), diff --git a/scripts/qapi/schema.py b/scripts/qapi/schema.py index 5100110fa2..8fbfa42e8e 100644 --- a/scripts/qapi/schema.py +++ b/scripts/qapi/schema.py @@ -128,7 +128,7 @@ class QAPISchemaVisitor(object): def visit_command(self, name, info, ifcond, arg_type, ret_type, gen, success_response, boxed, allow_oob, allow_preconfig, - features): + coroutine, features): pass def visit_event(self, name, info, ifcond, arg_type, boxed): @@ -690,7 +690,7 @@ class QAPISchemaCommand(QAPISchemaEntity): def __init__(self, name, info, doc, ifcond, arg_type, ret_type, gen, success_response, boxed, allow_oob, allow_preconfig, - features): + coroutine, features): QAPISchemaEntity.__init__(self, name, info, doc, ifcond, features) assert not arg_type or isinstance(arg_type, str) assert not ret_type or isinstance(ret_type, str) @@ -703,6 +703,7 @@ class QAPISchemaCommand(QAPISchemaEntity): self.boxed = boxed self.allow_oob = allow_oob self.allow_preconfig = allow_preconfig + self.coroutine = coroutine def check(self, schema): QAPISchemaEntity.check(self, schema) @@ -745,7 +746,7 @@ class QAPISchemaCommand(QAPISchemaEntity): self.arg_type, self.ret_type, self.gen, self.success_response, self.boxed, self.allow_oob, - self.allow_preconfig, + self.allow_preconfig, self.coroutine, self.features) @@ -1043,6 +1044,7 @@ class QAPISchema(object): boxed = expr.get('boxed', False) allow_oob = expr.get('allow-oob', False) allow_preconfig = expr.get('allow-preconfig', False) + coroutine = expr.get('coroutine', False) ifcond = expr.get('if') features = expr.get('features', []) if isinstance(data, OrderedDict): @@ -1054,6 +1056,7 @@ class QAPISchema(object): self._def_entity(QAPISchemaCommand(name, info, doc, ifcond, data, rets, gen, success_response, boxed, allow_oob, allow_preconfig, + coroutine, self._make_features(features, info))) def _def_event(self, expr, info, doc): diff --git a/tests/qapi-schema/test-qapi.py b/tests/qapi-schema/test-qapi.py index 41232c11a3..dcb922755d 100755 --- a/tests/qapi-schema/test-qapi.py +++ b/tests/qapi-schema/test-qapi.py @@ -69,12 +69,13 @@ class QAPISchemaTestVisitor(QAPISchemaVisitor): def visit_command(self, name, info, ifcond, arg_type, ret_type, gen, success_response, boxed, allow_oob, allow_preconfig, - features): + coroutine, features): 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 preconfig=%s' - % (gen, success_response, boxed, allow_oob, allow_preconfig)) + print(' gen=%s success_response=%s boxed=%s oob=%s preconfig=%s%s' + % (gen, success_response, boxed, allow_oob, allow_preconfig, + " coroutine=True" if coroutine else "")) self._print_if(ifcond) self._print_features(features) diff --git a/tests/Makefile.include b/tests/Makefile.include index 2f1cafed72..893540f5a3 100644 --- a/tests/Makefile.include +++ b/tests/Makefile.include @@ -286,6 +286,7 @@ qapi-schema += missing-type.json qapi-schema += nested-struct-data.json qapi-schema += nested-struct-data-invalid-dict.json qapi-schema += non-objects.json +qapi-schema += oob-coroutine.json qapi-schema += oob-test.json qapi-schema += allow-preconfig-test.json qapi-schema += pragma-doc-required-crap.json diff --git a/tests/qapi-schema/oob-coroutine.err b/tests/qapi-schema/oob-coroutine.err new file mode 100644 index 0000000000..c01a4992bd --- /dev/null +++ b/tests/qapi-schema/oob-coroutine.err @@ -0,0 +1,2 @@ +oob-coroutine.json: In command 'oob-command-1': +oob-coroutine.json:2: flags 'allow-oob' and 'coroutine' are incompatible diff --git a/tests/qapi-schema/oob-coroutine.json b/tests/qapi-schema/oob-coroutine.json new file mode 100644 index 0000000000..0f67663bcd --- /dev/null +++ b/tests/qapi-schema/oob-coroutine.json @@ -0,0 +1,2 @@ +# Check that incompatible flags allow-oob and coroutine are rejected +{ 'command': 'oob-command-1', 'allow-oob': true, 'coroutine': true } diff --git a/tests/qapi-schema/oob-coroutine.out b/tests/qapi-schema/oob-coroutine.out new file mode 100644 index 0000000000..e69de29bb2 diff --git a/tests/qapi-schema/qapi-schema-test.json b/tests/qapi-schema/qapi-schema-test.json index 9abf175fe0..1a850fe171 100644 --- a/tests/qapi-schema/qapi-schema-test.json +++ b/tests/qapi-schema/qapi-schema-test.json @@ -147,6 +147,7 @@ 'returns': 'UserDefTwo' } { 'command': 'cmd-success-response', 'data': {}, 'success-response': false } +{ 'command': 'coroutine-cmd', 'data': {}, 'coroutine': true } # Returning a non-dictionary requires a name from the whitelist { 'command': 'guest-get-time', 'data': {'a': 'int', '*b': 'int' }, diff --git a/tests/qapi-schema/qapi-schema-test.out b/tests/qapi-schema/qapi-schema-test.out index 9bd3c4a490..fdc349991a 100644 --- a/tests/qapi-schema/qapi-schema-test.out +++ b/tests/qapi-schema/qapi-schema-test.out @@ -203,6 +203,8 @@ command user_def_cmd2 q_obj_user_def_cmd2-arg -> UserDefTwo gen=True success_response=True boxed=False oob=False preconfig=False command cmd-success-response None -> None gen=True success_response=False boxed=False oob=False preconfig=False +command coroutine-cmd None -> None + gen=True success_response=True boxed=False oob=False preconfig=False coroutine=True object q_obj_guest-get-time-arg member a: int optional=False member b: int optional=True -- 2.20.1