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qapi: New QMP command query-qmp-schema for QMP introspection

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qapi/introspect.json defines the introspection schema.  It's designed
for QMP introspection, but should do for similar uses, such as QGA.

The introspection schema does not reflect all the rules and
restrictions that apply to QAPI schemata.  A valid QAPI schema has an
introspection value conforming to the introspection schema, but the
converse is not true.

Introspection lowers away a number of schema details, and makes
implicit things explicit:

* The built-in types are declared with their JSON type.

  All integer types are mapped to 'int', because how many bits we use
  internally is an implementation detail.  It could be pressed into
  external interface service as very approximate range information,
  but that's a bad idea.  If we need range information, we better do
  it properly.

* Implicit type definitions are made explicit, and given
  auto-generated names:

  - Array types, named by appending "List" to the name of their
    element type, like in generated C.

  - The enumeration types implicitly defined by simple union types,
    named by appending "Kind" to the name of their simple union type,
    like in generated C.

  - Types that don't occur in generated C.  Their names start with ':'
    so they don't clash with the user's names.

* All type references are by name.

* The struct and union types are generalized into an object type.

* Base types are flattened.

* Commands take a single argument and return a single result.

  Dictionary argument or list result is an implicit type definition.

  The empty object type is used when a command takes no arguments or
  produces no results.

  The argument is always of object type, but the introspection schema
  doesn't reflect that.

  The 'gen': false directive is omitted as implementation detail.

  The 'success-response' directive is omitted as well for now, even
  though it's not an implementation detail, because it's not used by
  QMP.

* Events carry a single data value.

  Implicit type definition and empty object type use, just like for
  commands.

  The value is of object type, but the introspection schema doesn't
  reflect that.

* Types not used by commands or events are omitted.

  Indirect use counts as use.

* Optional members have a default, which can only be null right now

  Instead of a mandatory "optional" flag, we have an optional default.
  No default means mandatory, default null means optional without
  default value.  Non-null is available for optional with default
  (possible future extension).

* Clients should *not* look up types by name, because type names are
  not ABI.  Look up the command or event you're interested in, then
  follow the references.

  TODO Should we hide the type names to eliminate the temptation?

New generator scripts/qapi-introspect.py computes an introspection
value for its input, and generates a C variable holding it.

It can generate awfully long lines.  Marked TODO.

A new test-qmp-input-visitor test case feeds its result for both
tests/qapi-schema/qapi-schema-test.json and qapi-schema.json to a
QmpInputVisitor to verify it actually conforms to the schema.

New QMP command query-qmp-schema takes its return value from that
variable.  Its reply is some 85KiBytes for me right now.

If this turns out to be too much, we have a couple of options:

* We can use shorter names in the JSON.  Not the QMP style.

* Optionally return the sub-schema for commands and events given as
  arguments.

  Right now qmp_query_schema() sends the string literal computed by
  qmp-introspect.py.  To compute sub-schema at run time, we'd have to
  duplicate parts of qapi-introspect.py in C.  Unattractive.

* Let clients cache the output of query-qmp-schema.

  It changes only on QEMU upgrades, i.e. rarely.  Provide a command
  query-qmp-schema-hash.  Clients can have a cache indexed by hash,
  and re-query the schema only when they don't have it cached.  Even
  simpler: put the hash in the QMP greeting.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
This commit is contained in:
Markus Armbruster 2015-09-16 13:06:28 +02:00
parent 2d21291ae6
commit 39a1815816
27 changed files with 830 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
.gitignore vendored
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@ -34,6 +34,7 @@
/qapi-visit.[ch]
/qapi-event.[ch]
/qmp-commands.h
/qmp-introspect.[ch]
/qmp-marshal.c
/qemu-doc.html
/qemu-tech.html

9
Makefile
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@ -52,6 +52,8 @@ endif
GENERATED_HEADERS = config-host.h qemu-options.def
GENERATED_HEADERS += qmp-commands.h qapi-types.h qapi-visit.h qapi-event.h
GENERATED_SOURCES += qmp-marshal.c qapi-types.c qapi-visit.c qapi-event.c
GENERATED_HEADERS += qmp-introspect.h
GENERATED_SOURCES += qmp-introspect.c
GENERATED_HEADERS += trace/generated-events.h
GENERATED_SOURCES += trace/generated-events.c
@ -269,7 +271,7 @@ $(SRC_PATH)/qga/qapi-schema.json $(SRC_PATH)/scripts/qapi-commands.py $(qapi-py)
qapi-modules = $(SRC_PATH)/qapi-schema.json $(SRC_PATH)/qapi/common.json \
$(SRC_PATH)/qapi/block.json $(SRC_PATH)/qapi/block-core.json \
$(SRC_PATH)/qapi/event.json
$(SRC_PATH)/qapi/event.json $(SRC_PATH)/qapi/introspect.json
qapi-types.c qapi-types.h :\
$(qapi-modules) $(SRC_PATH)/scripts/qapi-types.py $(qapi-py)
@ -291,6 +293,11 @@ $(qapi-modules) $(SRC_PATH)/scripts/qapi-commands.py $(qapi-py)
$(call quiet-command,$(PYTHON) $(SRC_PATH)/scripts/qapi-commands.py \
$(gen-out-type) -o "." -m $<, \
" GEN $@")
qmp-introspect.h qmp-introspect.c :\
$(qapi-modules) $(SRC_PATH)/scripts/qapi-introspect.py $(qapi-py)
$(call quiet-command,$(PYTHON) $(SRC_PATH)/scripts/qapi-introspect.py \
$(gen-out-type) -o "." $<, \
" GEN $@")
QGALIB_GEN=$(addprefix qga/qapi-generated/, qga-qapi-types.h qga-qapi-visit.h qga-qmp-commands.h)
$(qga-obj-y) qemu-ga.o: $(QGALIB_GEN)

4
Makefile.objs
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@ -1,7 +1,8 @@
#######################################################################
# Common libraries for tools and emulators
stub-obj-y = stubs/
util-obj-y = util/ qobject/ qapi/ qapi-types.o qapi-visit.o qapi-event.o
util-obj-y = util/ qobject/ qapi/
util-obj-y += qmp-introspect.o qapi-types.o qapi-visit.o qapi-event.o
#######################################################################
# block-obj-y is code used by both qemu system emulation and qemu-img
@ -92,6 +93,7 @@ common-obj-$(CONFIG_FDT) += device_tree.o
# qapi
common-obj-y += qmp-marshal.o
common-obj-y += qmp-introspect.o
common-obj-y += qmp.o hmp.o
endif

237
docs/qapi-code-gen.txt
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@ -502,13 +502,206 @@ Resulting in this JSON object:
"timestamp": { "seconds": 1267020223, "microseconds": 435656 } }
== Client JSON Protocol introspection ==
Clients of a Client JSON Protocol commonly need to figure out what
exactly the server (QEMU) supports.
For this purpose, QMP provides introspection via command
query-qmp-schema. QGA currently doesn't support introspection.
query-qmp-schema returns a JSON array of SchemaInfo objects. These
objects together describe the wire ABI, as defined in the QAPI schema.
However, the SchemaInfo can't reflect all the rules and restrictions
that apply to QMP. It's interface introspection (figuring out what's
there), not interface specification. The specification is in the QAPI
schema. To understand how QMP is to be used, you need to study the
QAPI schema.
Like any other command, query-qmp-schema is itself defined in the QAPI
schema, along with the SchemaInfo type. This text attempts to give an
overview how things work. For details you need to consult the QAPI
schema.
SchemaInfo objects have common members "name" and "meta-type", and
additional variant members depending on the value of meta-type.
Each SchemaInfo object describes a wire ABI entity of a certain
meta-type: a command, event or one of several kinds of type.
SchemaInfo for entities defined in the QAPI schema have the same name
as in the schema. This is the case for all commands and events, and
most types.
Command and event names are part of the wire ABI, but type names are
not. Therefore, looking up a type by its name in the QAPI schema is
wrong. Look up the command or event, then follow references by name.
QAPI schema definitions not reachable that way are omitted.
The SchemaInfo for a command has meta-type "command", and variant
members "arg-type" and "ret-type". On the wire, the "arguments"
member of a client's "execute" command must conform to the object type
named by "arg-type". The "return" member that the server passes in a
success response conforms to the type named by "ret-type".
If the command takes no arguments, "arg-type" names an object type
without members. Likewise, if the command returns nothing, "ret-type"
names an object type without members.
Example: the SchemaInfo for command query-qmp-schema
{ "name": "query-qmp-schema", "meta-type": "command",
"arg-type": ":empty", "ret-type": "SchemaInfoList" }
Type ":empty" is an object type without members, and type
"SchemaInfoList" is the array of SchemaInfo type.
The SchemaInfo for an event has meta-type "event", and variant member
"arg-type". On the wire, a "data" member that the server passes in an
event conforms to the object type named by "arg-type".
If the event carries no additional information, "arg-type" names an
object type without members. The event may not have a data member on
the wire then.
Each command or event defined with dictionary-valued 'data' in the
QAPI schema implicitly defines an object type called ":obj-NAME-arg",
where NAME is the command or event's name.
Example: the SchemaInfo for EVENT_C from section Events
{ "name": "EVENT_C", "meta-type": "event",
"arg-type": ":obj-EVENT_C-arg" }
Type ":obj-EVENT_C-arg" is an implicitly defined object type with
the two members from the event's definition.
The SchemaInfo for struct and union types has meta-type "object".
The SchemaInfo for a struct type has variant member "members".
The SchemaInfo for a union type additionally has variant members "tag"
and "variants".
"members" is a JSON array describing the object's common members, if
any. Each element is a JSON object with members "name" (the member's
name), "type" (the name of its type), and optionally "default". The
member is optional if "default" is present. Currently, "default" can
only have value null. Other values are reserved for future
extensions.
Example: the SchemaInfo for MyType from section Struct types
{ "name": "MyType", "meta-type": "object",
"members": [
{ "name": "member1", "type": "str" },
{ "name": "member2", "type": "int" },
{ "name": "member3", "type": "str", "default": null } ] }
"tag" is the name of the common member serving as type tag.
"variants" is a JSON array describing the object's variant members.
Each element is a JSON object with members "case" (the value of type
tag this element applies to) and "type" (the name of an object type
that provides the variant members for this type tag value).
Example: the SchemaInfo for flat union BlockdevOptions from section
Union types
{ "name": "BlockdevOptions", "meta-type": "object",
"members": [
{ "name": "driver", "type": "BlockdevDriver" },
{ "name": "readonly", "type": "bool"} ],
"tag": "driver",
"variants": [
{ "case": "file", "type": "FileOptions" },
{ "case": "qcow2", "type": "Qcow2Options" } ] }
Note that base types are "flattened": its members are included in the
"members" array.
A simple union implicitly defines an enumeration type for its implicit
discriminator (called "type" on the wire, see section Union types).
Such a type's name is made by appending "Kind" to the simple union's
name.
A simple union implicitly defines an object type for each of its
variants. The type's name is ":obj-NAME-wrapper", where NAME is the
name of the name of the variant's type.
Example: the SchemaInfo for simple union BlockdevOptions from section
Union types
{ "name": "BlockdevOptions", "meta-type": "object",
"members": [
{ "name": "kind", "type": "BlockdevOptionsKind" } ],
"tag": "type",
"variants": [
{ "case": "file", "type": ":obj-FileOptions-wrapper" },
{ "case": "qcow2", "type": ":obj-Qcow2Options-wrapper" } ] }
Enumeration type "BlockdevOptionsKind" and the object types
":obj-FileOptions-wrapper", ":obj-Qcow2Options-wrapper" are
implicitly defined.
The SchemaInfo for an alternate type has meta-type "alternate", and
variant member "members". "members" is a JSON array. Each element is
a JSON object with member "type", which names a type. Values of the
alternate type conform to exactly one of its member types.
Example: the SchemaInfo for BlockRef from section Alternate types
{ "name": "BlockRef", "meta-type": "alternate",
"members": [
{ "type": "BlockdevOptions" },
{ "type": "str" } ] }
The SchemaInfo for an array type has meta-type "array", and variant
member "element-type", which names the array's element type. Array
types are implicitly defined. An array type's name is made by
appending "List" to its element type's name.
Example: the SchemaInfo for ['str']
{ "name": "strList", "meta-type": "array",
"element-type": "str" }
The SchemaInfo for an enumeration type has meta-type "enum" and
variant member "values".
Example: the SchemaInfo for MyEnum from section Enumeration types
{ "name": "MyEnum", "meta-type": "enum",
"values": [ "value1", "value2", "value3" ] }
The SchemaInfo for a built-in type has the same name as the type in
the QAPI schema (see section Built-in Types), with one exception
detailed below. It has variant member "json-type" that shows how
values of this type are encoded on the wire.
Example: the SchemaInfo for str
{ "name": "str", "meta-type": "builtin", "json-type": "string" }
The QAPI schema supports a number of integer types that only differ in
how they map to C. They are identical as far as SchemaInfo is
concerned. Therefore, they get all mapped to a single type "int" in
SchemaInfo.
As explained above, type names are not part of the wire ABI. Not even
the names of built-in types. Clients should examine member
"json-type" instead of hard-coding names of built-in types.
== Code generation ==
Schemas are fed into 3 scripts to generate all the code/files that, paired
with the core QAPI libraries, comprise everything required to take JSON
commands read in by a Client JSON Protocol server, unmarshal the arguments into
the underlying C types, call into the corresponding C function, and map the
response back to a Client JSON Protocol response to be returned to the user.
Schemas are fed into four scripts to generate all the code/files that,
paired with the core QAPI libraries, comprise everything required to
take JSON commands read in by a Client JSON Protocol server, unmarshal
the arguments into the underlying C types, call into the corresponding
C function, and map the response back to a Client JSON Protocol
response to be returned to the user.
As an example, we'll use the following schema, which describes a single
complex user-defined type (which will produce a C struct, along with a list
@ -856,3 +1049,37 @@ Example:
extern const char *const example_QAPIEvent_lookup[];
#endif
=== scripts/qapi-introspect.py ===
Used to generate the introspection C code for a schema. The following
files are created:
$(prefix)qmp-introspect.c - Defines a string holding a JSON
description of the schema.
$(prefix)qmp-introspect.h - Declares the above string.
Example:
$ python scripts/qapi-introspect.py --output-dir="qapi-generated"
--prefix="example-" example-schema.json
$ cat qapi-generated/example-qmp-introspect.c
[Uninteresting stuff omitted...]
const char example_qmp_schema_json[] = "["
"{\"arg-type\": \":empty\", \"meta-type\": \"event\", \"name\": \"MY_EVENT\"}, "
"{\"json-type\": \"int\", \"meta-type\": \"builtin\", \"name\": \"int\"}, "
"{\"json-type\": \"string\", \"meta-type\": \"builtin\", \"name\": \"str\"}, "
"{\"members\": [], \"meta-type\": \"object\", \"name\": \":empty\"}, "
"{\"members\": [{\"name\": \"arg1\", \"type\": \"UserDefOne\"}], \"meta-type\": \"object\", \"name\": \":obj-my-command-arg\"}, "
"{\"members\": [{\"name\": \"integer\", \"type\": \"int\"}, {\"name\": \"string\", \"type\": \"str\"}], \"meta-type\": \"object\", \"name\": \"UserDefOne\"}, "
"{\"arg-type\": \":obj-my-command-arg\", \"meta-type\": \"command\", \"name\": \"my-command\", \"ret-type\": \"UserDefOne\"}]";
$ cat qapi-generated/example-qmp-introspect.h
[Uninteresting stuff omitted...]
#ifndef EXAMPLE_QMP_INTROSPECT_H
#define EXAMPLE_QMP_INTROSPECT_H
extern const char example_qmp_schema_json[];
#endif

16
monitor.c
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@ -74,6 +74,7 @@
#include "block/qapi.h"
#include "qapi/qmp-event.h"
#include "qapi-event.h"
#include "qmp-introspect.h"
#include "sysemu/block-backend.h"
/* for hmp_info_irq/pic */
@ -928,6 +929,21 @@ EventInfoList *qmp_query_events(Error **errp)
return ev_list;
}
/*
* Minor hack: generated marshalling suppressed for this command
* ('gen': false in the schema) so we can parse the JSON string
* directly into QObject instead of first parsing it with
* visit_type_SchemaInfoList() into a SchemaInfoList, then marshal it
* to QObject with generated output marshallers, every time. Instead,
* we do it in test-qmp-input-visitor.c, just to make sure
* qapi-introspect.py's output actually conforms to the schema.
*/
static void qmp_query_qmp_schema(QDict *qdict, QObject **ret_data,
Error **errp)
{
*ret_data = qobject_from_json(qmp_schema_json);
}
/* set the current CPU defined by the user */
int monitor_set_cpu(int cpu_index)
{

3
qapi-schema.json
View File

@ -17,6 +17,9 @@
# Tracing commands
{ 'include': 'qapi/trace.json' }
# QAPI introspection
{ 'include': 'qapi/introspect.json' }
##
# @LostTickPolicy:
#

277
qapi/introspect.json Normal file
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@ -0,0 +1,277 @@
# -*- Mode: Python -*-
#
# QAPI/QMP introspection
#
# Copyright (C) 2015 Red Hat, Inc.
#
# Authors:
# Markus Armbruster <armbru@redhat.com>
#
# This work is licensed under the terms of the GNU GPL, version 2 or later.
# See the COPYING file in the top-level directory.
##
# @query-qmp-schema
#
# Command query-qmp-schema exposes the QMP wire ABI as an array of
# SchemaInfo. This lets QMP clients figure out what commands and
# events are available in this QEMU, and their parameters and results.
#
# However, the SchemaInfo can't reflect all the rules and restrictions
# that apply to QMP. It's interface introspection (figuring out
# what's there), not interface specification. The specification is in
# the QAPI schema.
#
# Returns: array of @SchemaInfo, where each element describes an
# entity in the ABI: command, event, type, ...
#
# Note: the QAPI schema is also used to help define *internal*
# interfaces, by defining QAPI types. These are not part of the QMP
# wire ABI, and therefore not returned by this command.
#
# Since: 2.5
##
{ 'command': 'query-qmp-schema',
'returns': [ 'SchemaInfo' ],
'gen': false } # just to simplify qmp_query_json()
##
# @SchemaMetaType
#
# This is a @SchemaInfo's meta type, i.e. the kind of entity it
# describes.
#
# @builtin: a predefined type such as 'int' or 'bool'.
#
# @enum: an enumeration type
#
# @array: an array type
#
# @object: an object type (struct or union)
#
# @alternate: an alternate type
#
# @command: a QMP command
#
# @event: a QMP event
#
# Since: 2.5
##
{ 'enum': 'SchemaMetaType',
'data': [ 'builtin', 'enum', 'array', 'object', 'alternate',
'command', 'event' ] }
##
# @SchemaInfoBase
#
# Members common to any @SchemaInfo.
#
# Since: 2.5
##
{ 'struct': 'SchemaInfoBase',
'data': { 'name': 'str', 'meta-type': 'SchemaMetaType' } }
##
# @SchemaInfo
#
# @name: the entity's name, inherited from @base.
# Entities defined in the QAPI schema have the name defined in
# the schema. Implicitly defined entities have generated
# names. See docs/qapi-code-gen.txt section "Client JSON
# Protocol introspection" for details.
#
# All references to other SchemaInfo are by name.
#
# Command and event names are part of the wire ABI, but type names are
# not. Therefore, looking up a type by "well-known" name is wrong.
# Look up the command or event, then follow the references.
#
# @meta-type: the entity's meta type, inherited from @base.
#
# Additional members depend on the value of @meta-type.
#
# Since: 2.5
##
{ 'union': 'SchemaInfo',
'base': 'SchemaInfoBase',
'discriminator': 'meta-type',
'data': {
'builtin': 'SchemaInfoBuiltin',
'enum': 'SchemaInfoEnum',
'array': 'SchemaInfoArray',
'object': 'SchemaInfoObject',
'alternate': 'SchemaInfoAlternate',
'command': 'SchemaInfoCommand',
'event': 'SchemaInfoEvent' } }
##
# @SchemaInfoBuiltin
#
# Additional SchemaInfo members for meta-type 'builtin'.
#
# @json-type: the JSON type used for this type on the wire.
#
# Since: 2.5
##
{ 'struct': 'SchemaInfoBuiltin',
'data': { 'json-type': 'JSONType' } }
##
# @JSONType
#
# The four primitive and two structured types according to RFC 7159
# section 1, plus 'int' (split off 'number'), plus the obvious top
# type 'value'.
#
# Since: 2.5
##
{ 'enum': 'JSONType',
'data': [ 'string', 'number', 'int', 'boolean', 'null',
'object', 'array', 'value' ] }
##
# @SchemaInfoEnum
#
# Additional SchemaInfo members for meta-type 'enum'.
#
# @values: the enumeration type's values.
#
# Values of this type are JSON string on the wire.
#
# Since: 2.5
##
{ 'struct': 'SchemaInfoEnum',
'data': { 'values': ['str'] } }
##
# @SchemaInfoArray
#
# Additional SchemaInfo members for meta-type 'array'.
#
# @element-type: the array type's element type.
#
# Values of this type are JSON array on the wire.
#
# Since: 2.5
##
{ 'struct': 'SchemaInfoArray',
'data': { 'element-type': 'str' } }
##
# @SchemaInfoObject
#
# Additional SchemaInfo members for meta-type 'object'.
#
# @members: the object type's (non-variant) members.
#
# @tag: #optional the name of the member serving as type tag.
# An element of @members with this name must exist.
#
# @variants: #optional variant members, i.e. additional members that
# depend on the type tag's value. Present exactly when
# @tag is present.
#
# Values of this type are JSON object on the wire.
#
# Since: 2.5
##
{ 'struct': 'SchemaInfoObject',
'data': { 'members': [ 'SchemaInfoObjectMember' ],
'*tag': 'str',
'*variants': [ 'SchemaInfoObjectVariant' ] } }
##
# @SchemaInfoObjectMember
#
# An object member.
#
# @name: the member's name, as defined in the QAPI schema.
#
# @type: the name of the member's type.
#
# @default: #optional default when used as command parameter.
# If absent, the parameter is mandatory.
# If present, the value must be null. The parameter is
# optional, and behavior when it's missing is not specified
# here.
# Future extension: if present and non-null, the parameter
# is optional, and defaults to this value.
#
# Since: 2.5
##
{ 'struct': 'SchemaInfoObjectMember',
'data': { 'name': 'str', 'type': 'str', '*default': 'any' } }
# @default's type must be null or match @type
##
# @SchemaInfoObjectVariant
#
# The variant members for a value of the type tag.
#
# @case: a value of the type tag.
#
# @type: the name of the object type that provides the variant members
# when the type tag has value @case.
#
# Since: 2.5
##
{ 'struct': 'SchemaInfoObjectVariant',
'data': { 'case': 'str', 'type': 'str' } }
##
# @SchemaInfoAlternate
#
# Additional SchemaInfo members for meta-type 'alternate'.
#
# @members: the alternate type's members.
# The members' wire encoding is distinct, see
# docs/qapi-code-gen.txt section Alternate types.
#
# On the wire, this can be any of the members.
#
# Since: 2.5
##
{ 'struct': 'SchemaInfoAlternate',
'data': { 'members': [ 'SchemaInfoAlternateMember' ] } }
##
# @SchemaInfoAlternateMember
#
# An alternate member.
#
# @type: the name of the member's type.
#
# Since: 2.5
##
{ 'struct': 'SchemaInfoAlternateMember',
'data': { 'type': 'str' } }
##
# @SchemaInfoCommand
#
# Additional SchemaInfo members for meta-type 'command'.
#
# @arg-type: the name of the object type that provides the command's
# parameters.
#
# @ret-type: the name of the command's result type.
#
# TODO @success-response (currently irrelevant, because it's QGA, not QMP)
#
# Since: 2.5
##
{ 'struct': 'SchemaInfoCommand',
'data': { 'arg-type': 'str', 'ret-type': 'str' } }
##
# @SchemaInfoEvent
#
# Additional SchemaInfo members for meta-type 'event'.
#
# @arg-type: the name of the object type that provides the event's
# parameters.
#
# Since: 2.5
##
{ 'struct': 'SchemaInfoEvent',
'data': { 'arg-type': 'str' } }

17
qmp-commands.hx
View File

@ -2192,6 +2192,23 @@ EQMP
.mhandler.cmd_new = qmp_marshal_query_events,
},
SQMP
query-qmp-schema
----------------
Return the QMP wire schema. The returned value is a json-array of
named schema entities. Entities are commands, events and various
types. See docs/qapi-code-gen.txt for information on their structure
and intended use.
EQMP
{
.name = "query-qmp-schema",
.args_type = "",
.mhandler.cmd_new = qmp_query_qmp_schema,
},
SQMP
query-chardev
-------------

184
scripts/qapi-introspect.py Normal file
View File

@ -0,0 +1,184 @@
#
# QAPI introspection generator
#
# Copyright (C) 2015 Red Hat, Inc.
#
# Authors:
# Markus Armbruster <armbru@redhat.com>
#
# This work is licensed under the terms of the GNU GPL, version 2.
# See the COPYING file in the top-level directory.
from qapi import *
# Caveman's json.dumps() replacement (we're stuck at Python 2.4)
# TODO try to use json.dumps() once we get unstuck
def to_json(obj, level=0):
if obj is None:
ret = 'null'
elif isinstance(obj, str):
ret = '"' + obj.replace('"', r'\"') + '"'
elif isinstance(obj, list):
elts = [to_json(elt, level + 1)
for elt in obj]
ret = '[' + ', '.join(elts) + ']'
elif isinstance(obj, dict):
elts = ['"%s": %s' % (key.replace('"', r'\"'),
to_json(obj[key], level + 1))
for key in sorted(obj.keys())]
ret = '{' + ', '.join(elts) + '}'
else:
assert False # not implemented
if level == 1:
ret = '\n' + ret
return ret
def to_c_string(string):
return '"' + string.replace('\\', r'\\').replace('"', r'\"') + '"'
class QAPISchemaGenIntrospectVisitor(QAPISchemaVisitor):
def __init__(self):
self.defn = None
self.decl = None
self._schema = None
self._jsons = None
self._used_types = None
def visit_begin(self, schema):
self._schema = schema
self._jsons = []
self._used_types = []
return QAPISchemaType # don't visit types for now
def visit_end(self):
# visit the types that are actually used
for typ in self._used_types:
typ.visit(self)
self._jsons.sort()
# generate C
# TODO can generate awfully long lines
name = prefix + 'qmp_schema_json'
self.decl = mcgen('''
extern const char %(c_name)s[];
''',
c_name=c_name(name))
lines = to_json(self._jsons).split('\n')
c_string = '\n '.join([to_c_string(line) for line in lines])
self.defn = mcgen('''
const char %(c_name)s[] = %(c_string)s;
''',
c_name=c_name(name),
c_string=c_string)
self._schema = None
self._jsons = None
self._used_types = None
def _use_type(self, typ):
# Map the various integer types to plain int
if typ.json_type() == 'int':
typ = self._schema.lookup_type('int')
elif (isinstance(typ, QAPISchemaArrayType) and
typ.element_type.json_type() == 'int'):
typ = self._schema.lookup_type('intList')
# Add type to work queue if new
if typ not in self._used_types:
self._used_types.append(typ)
return typ.name
def _gen_json(self, name, mtype, obj):
obj['name'] = name
obj['meta-type'] = mtype
self._jsons.append(obj)
def _gen_member(self, member):
ret = {'name': member.name, 'type': self._use_type(member.type)}
if member.optional:
ret['default'] = None
return ret
def _gen_variants(self, tag_name, variants):
return {'tag': tag_name,
'variants': [self._gen_variant(v) for v in variants]}
def _gen_variant(self, variant):
return {'case': variant.name, 'type': self._use_type(variant.type)}
def visit_builtin_type(self, name, info, json_type):
self._gen_json(name, 'builtin', {'json-type': json_type})
def visit_enum_type(self, name, info, values, prefix):
self._gen_json(name, 'enum', {'values': values})
def visit_array_type(self, name, info, element_type):
self._gen_json(name, 'array',
{'element-type': self._use_type(element_type)})
def visit_object_type_flat(self, name, info, members, variants):
obj = {'members': [self._gen_member(m) for m in members]}
if variants:
obj.update(self._gen_variants(variants.tag_member.name,
variants.variants))
self._gen_json(name, 'object', obj)
def visit_alternate_type(self, name, info, variants):
self._gen_json(name, 'alternate',
{'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):
arg_type = arg_type or self._schema.the_empty_object_type
ret_type = ret_type or self._schema.the_empty_object_type
self._gen_json(name, 'command',
{'arg-type': self._use_type(arg_type),
'ret-type': self._use_type(ret_type)})
def visit_event(self, name, info, arg_type):
arg_type = arg_type or self._schema.the_empty_object_type
self._gen_json(name, 'event', {'arg-type': self._use_type(arg_type)})
(input_file, output_dir, do_c, do_h, prefix, dummy) = parse_command_line()
c_comment = '''
/*
* QAPI/QMP schema introspection
*
* Copyright (C) 2015 Red Hat, Inc.
*
* This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
* See the COPYING.LIB file in the top-level directory.
*
*/
'''
h_comment = '''
/*
* QAPI/QMP schema introspection
*
* Copyright (C) 2015 Red Hat, Inc.
*
* This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
* See the COPYING.LIB file in the top-level directory.
*
*/
'''
(fdef, fdecl) = open_output(output_dir, do_c, do_h, prefix,
'qmp-introspect.c', 'qmp-introspect.h',
c_comment, h_comment)
fdef.write(mcgen('''
#include "%(prefix)sqmp-introspect.h"
''',
prefix=prefix))
schema = QAPISchema(input_file)
gen = QAPISchemaGenIntrospectVisitor()
schema.visit(gen)
fdef.write(gen.defn)
fdecl.write(gen.decl)
close_output(fdef, fdecl)

13
scripts/qapi.py
View File

@ -788,6 +788,9 @@ class QAPISchemaVisitor(object):
def visit_object_type(self, name, info, base, members, variants):
pass
def visit_object_type_flat(self, name, info, members, variants):
pass
def visit_alternate_type(self, name, info, variants):
pass
@ -943,6 +946,8 @@ class QAPISchemaObjectType(QAPISchemaType):
def visit(self, visitor):
visitor.visit_object_type(self.name, self.info,
self.base, self.local_members, self.variants)
visitor.visit_object_type_flat(self.name, self.info,
self.members, self.variants)
class QAPISchemaObjectTypeMember(object):
@ -1113,6 +1118,9 @@ class QAPISchema(object):
('bool', 'boolean', 'bool', 'false'),
('any', 'value', 'QObject' + pointer_suffix, 'NULL')]:
self._def_builtin_type(*t)
self.the_empty_object_type = QAPISchemaObjectType(':empty', None, None,
[], None)
self._def_entity(self.the_empty_object_type)
def _make_implicit_enum_type(self, name, values):
name = name + 'Kind'
@ -1260,9 +1268,10 @@ class QAPISchema(object):
ent.check(self)
def visit(self, visitor):
visitor.visit_begin(self)
ignore = visitor.visit_begin(self)
for name in sorted(self._entity_dict.keys()):
self._entity_dict[name].visit(visitor)
if not ignore or not isinstance(self._entity_dict[name], ignore):
self._entity_dict[name].visit(visitor)
visitor.visit_end()

1
tests/.gitignore vendored
View File

@ -35,6 +35,7 @@ test-qmp-commands.h
test-qmp-event
test-qmp-input-strict
test-qmp-input-visitor
test-qmp-introspect.[ch]
test-qmp-marshal.c
test-qmp-output-visitor
test-rcu-list

10
tests/Makefile
View File

@ -269,7 +269,8 @@ check-qapi-schema-y := $(addprefix tests/qapi-schema/, \
struct-base-clash.json struct-base-clash-deep.json )
GENERATED_HEADERS += tests/test-qapi-types.h tests/test-qapi-visit.h \
tests/test-qmp-commands.h tests/test-qapi-event.h
tests/test-qmp-commands.h tests/test-qapi-event.h \
tests/test-qmp-introspect.h
test-obj-y = tests/check-qint.o tests/check-qstring.o tests/check-qdict.o \
tests/check-qlist.o tests/check-qfloat.o tests/check-qjson.o \
@ -289,7 +290,7 @@ QEMU_CFLAGS += -I$(SRC_PATH)/tests
test-util-obj-y = libqemuutil.a libqemustub.a
test-qom-obj-y = $(qom-obj-y) $(test-util-obj-y)
test-qapi-obj-y = tests/test-qapi-visit.o tests/test-qapi-types.o \
tests/test-qapi-event.o \
tests/test-qapi-event.o tests/test-qmp-introspect.o \
$(test-qom-obj-y)
test-crypto-obj-y = $(crypto-obj-y) $(test-qom-obj-y)
test-block-obj-y = $(block-obj-y) $(test-crypto-obj-y)
@ -346,6 +347,11 @@ $(SRC_PATH)/tests/qapi-schema/qapi-schema-test.json $(SRC_PATH)/scripts/qapi-eve
$(call quiet-command,$(PYTHON) $(SRC_PATH)/scripts/qapi-event.py \
$(gen-out-type) -o tests -p "test-" $<, \
" GEN $@")
tests/test-qmp-introspect.c tests/test-qmp-introspect.h :\
$(SRC_PATH)/tests/qapi-schema/qapi-schema-test.json $(SRC_PATH)/scripts/qapi-introspect.py $(qapi-py)
$(call quiet-command,$(PYTHON) $(SRC_PATH)/scripts/qapi-introspect.py \
$(gen-out-type) -o tests -p "test-" $<, \
" GEN $@")
tests/test-string-output-visitor$(EXESUF): tests/test-string-output-visitor.o $(test-qapi-obj-y)
tests/test-string-input-visitor$(EXESUF): tests/test-string-input-visitor.o $(test-qapi-obj-y)

1
tests/qapi-schema/alternate-good.out
View File

@ -1,3 +1,4 @@
object :empty
alternate Alt
case value: int
case string: Enum

1
tests/qapi-schema/args-member-array.out
View File

@ -1,3 +1,4 @@
object :empty
object :obj-okay-arg
member member1: intList optional=False
member member2: defList optional=False

1
tests/qapi-schema/comments.out
View File

@ -1 +1,2 @@
object :empty
enum Status ['good', 'bad', 'ugly']

1
tests/qapi-schema/empty.out
View File

@ -0,0 +1 @@
object :empty

1
tests/qapi-schema/enum-empty.out
View File

@ -1 +1,2 @@
object :empty
enum MyEnum []

1
tests/qapi-schema/event-case.out
View File

@ -1 +1,2 @@
object :empty
event oops None

1
tests/qapi-schema/flat-union-reverse-define.out
View File

@ -1,3 +1,4 @@
object :empty
object TestBase
member enum1: TestEnum optional=False
enum TestEnum ['value1', 'value2']

1
tests/qapi-schema/ident-with-escape.out
View File

@ -1,3 +1,4 @@
object :empty
object :obj-fooA-arg
member bar1: str optional=False
command fooA :obj-fooA-arg -> None

1
tests/qapi-schema/include-relpath.out
View File

@ -1 +1,2 @@
object :empty
enum Status ['good', 'bad', 'ugly']

1
tests/qapi-schema/include-repetition.out
View File

@ -1 +1,2 @@
object :empty
enum Status ['good', 'bad', 'ugly']

1
tests/qapi-schema/include-simple.out
View File

@ -1 +1,2 @@
object :empty
enum Status ['good', 'bad', 'ugly']

1
tests/qapi-schema/indented-expr.out
View File

@ -1,3 +1,4 @@
object :empty
command eins None -> None
gen=True success_response=True
command zwei None -> None

1
tests/qapi-schema/qapi-schema-test.out
View File

@ -1,3 +1,4 @@
object :empty
object :obj-EVENT_C-arg
member a: int optional=True
member b: UserDefOne optional=True

1
tests/qapi-schema/returns-int.out
View File

@ -1,2 +1,3 @@
object :empty
command guest-get-time None -> int
gen=True success_response=True

55
tests/test-qmp-input-strict.c
View File

@ -19,6 +19,9 @@
#include "test-qapi-types.h"
#include "test-qapi-visit.h"
#include "qapi/qmp/types.h"
#include "test-qmp-introspect.h"
#include "qmp-introspect.h"
#include "qapi-visit.h"
typedef struct TestInputVisitorData {
QObject *obj;
@ -62,6 +65,30 @@ Visitor *validate_test_init(TestInputVisitorData *data,
return v;
}
/* similar to validate_test_init(), but does not expect a string
* literal/format json_string argument and so can be used for
* programatically generated strings (and we can't pass in programatically
* generated strings via %s format parameters since qobject_from_jsonv()
* will wrap those in double-quotes and treat the entire object as a
* string)
*/
static Visitor *validate_test_init_raw(TestInputVisitorData *data,
const char *json_string)
{
Visitor *v;
data->obj = qobject_from_json(json_string);
g_assert(data->obj != NULL);
data->qiv = qmp_input_visitor_new_strict(data->obj);
g_assert(data->qiv != NULL);
v = qmp_input_get_visitor(data->qiv);
g_assert(v != NULL);
return v;
}
typedef struct TestStruct
{
int64_t integer;
@ -293,6 +320,32 @@ static void test_validate_fail_alternate(TestInputVisitorData *data,
qapi_free_UserDefAlternate(tmp);
}
static void do_test_validate_qmp_introspect(TestInputVisitorData *data,
const char *schema_json)
{
SchemaInfoList *schema = NULL;
Error *err = NULL;
Visitor *v;
v = validate_test_init_raw(data, schema_json);
visit_type_SchemaInfoList(v, &schema, NULL, &err);
if (err) {
fprintf(stderr, "%s", error_get_pretty(err));
}
g_assert(!err);
g_assert(schema);
qapi_free_SchemaInfoList(schema);
}
static void test_validate_qmp_introspect(TestInputVisitorData *data,
const void *unused)
{
do_test_validate_qmp_introspect(data, test_qmp_schema_json);
do_test_validate_qmp_introspect(data, qmp_schema_json);
}
static void validate_test_add(const char *testpath,
TestInputVisitorData *data,
void (*test_func)(TestInputVisitorData *data, const void *user_data))
@ -333,6 +386,8 @@ int main(int argc, char **argv)
&testdata, test_validate_fail_alternate);
validate_test_add("/visitor/input-strict/fail/union-native-list",
&testdata, test_validate_fail_union_native_list);
validate_test_add("/visitor/input-strict/pass/qmp-introspect",
&testdata, test_validate_qmp_introspect);
g_test_run();