cachepc-qemu

Fork of AMDESE/qemu with changes for cachepc side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-qemu
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introspect.py (13902B)

      1"""
      2QAPI introspection generator
      3
      4Copyright (C) 2015-2021 Red Hat, Inc.
      5
      6Authors:
      7 Markus Armbruster <armbru@redhat.com>
      8 John Snow <jsnow@redhat.com>
      9
     10This work is licensed under the terms of the GNU GPL, version 2.
     11See the COPYING file in the top-level directory.
     12"""
     13
     14from typing import (
     15    Any,
     16    Dict,
     17    Generic,
     18    List,
     19    Optional,
     20    Sequence,
     21    TypeVar,
     22    Union,
     23)
     24
     25from .common import c_name, mcgen
     26from .gen import QAPISchemaMonolithicCVisitor
     27from .schema import (
     28    QAPISchema,
     29    QAPISchemaArrayType,
     30    QAPISchemaBuiltinType,
     31    QAPISchemaEntity,
     32    QAPISchemaEnumMember,
     33    QAPISchemaFeature,
     34    QAPISchemaIfCond,
     35    QAPISchemaObjectType,
     36    QAPISchemaObjectTypeMember,
     37    QAPISchemaType,
     38    QAPISchemaVariant,
     39    QAPISchemaVariants,
     40)
     41from .source import QAPISourceInfo
     42
     43
     44# This module constructs a tree data structure that is used to
     45# generate the introspection information for QEMU. It is shaped
     46# like a JSON value.
     47#
     48# A complexity over JSON is that our values may or may not be annotated.
     49#
     50# Un-annotated values may be:
     51#     Scalar: str, bool, None.
     52#     Non-scalar: List, Dict
     53# _value = Union[str, bool, None, Dict[str, JSONValue], List[JSONValue]]
     54#
     55# With optional annotations, the type of all values is:
     56# JSONValue = Union[_Value, Annotated[_Value]]
     57#
     58# Sadly, mypy does not support recursive types; so the _Stub alias is used to
     59# mark the imprecision in the type model where we'd otherwise use JSONValue.
     60_Stub = Any
     61_Scalar = Union[str, bool, None]
     62_NonScalar = Union[Dict[str, _Stub], List[_Stub]]
     63_Value = Union[_Scalar, _NonScalar]
     64JSONValue = Union[_Value, 'Annotated[_Value]']
     65
     66# These types are based on structures defined in QEMU's schema, so we
     67# lack precise types for them here. Python 3.6 does not offer
     68# TypedDict constructs, so they are broadly typed here as simple
     69# Python Dicts.
     70SchemaInfo = Dict[str, object]
     71SchemaInfoObject = Dict[str, object]
     72SchemaInfoObjectVariant = Dict[str, object]
     73SchemaInfoObjectMember = Dict[str, object]
     74SchemaInfoCommand = Dict[str, object]
     75
     76
     77_ValueT = TypeVar('_ValueT', bound=_Value)
     78
     79
     80class Annotated(Generic[_ValueT]):
     81    """
     82    Annotated generally contains a SchemaInfo-like type (as a dict),
     83    But it also used to wrap comments/ifconds around scalar leaf values,
     84    for the benefit of features and enums.
     85    """
     86    # TODO: Remove after Python 3.7 adds @dataclass:
     87    # pylint: disable=too-few-public-methods
     88    def __init__(self, value: _ValueT, ifcond: QAPISchemaIfCond,
     89                 comment: Optional[str] = None):
     90        self.value = value
     91        self.comment: Optional[str] = comment
     92        self.ifcond = ifcond
     93
     94
     95def _tree_to_qlit(obj: JSONValue,
     96                  level: int = 0,
     97                  dict_value: bool = False) -> str:
     98    """
     99    Convert the type tree into a QLIT C string, recursively.
    100
    101    :param obj: The value to convert.
    102                This value may not be Annotated when dict_value is True.
    103    :param level: The indentation level for this particular value.
    104    :param dict_value: True when the value being processed belongs to a
    105                       dict key; which suppresses the output indent.
    106    """
    107
    108    def indent(level: int) -> str:
    109        return level * 4 * ' '
    110
    111    if isinstance(obj, Annotated):
    112        # NB: _tree_to_qlit is called recursively on the values of a
    113        # key:value pair; those values can't be decorated with
    114        # comments or conditionals.
    115        msg = "dict values cannot have attached comments or if-conditionals."
    116        assert not dict_value, msg
    117
    118        ret = ''
    119        if obj.comment:
    120            ret += indent(level) + f"/* {obj.comment} */\n"
    121        if obj.ifcond.is_present():
    122            ret += obj.ifcond.gen_if()
    123        ret += _tree_to_qlit(obj.value, level)
    124        if obj.ifcond.is_present():
    125            ret += '\n' + obj.ifcond.gen_endif()
    126        return ret
    127
    128    ret = ''
    129    if not dict_value:
    130        ret += indent(level)
    131
    132    # Scalars:
    133    if obj is None:
    134        ret += 'QLIT_QNULL'
    135    elif isinstance(obj, str):
    136        ret += f"QLIT_QSTR({to_c_string(obj)})"
    137    elif isinstance(obj, bool):
    138        ret += f"QLIT_QBOOL({str(obj).lower()})"
    139
    140    # Non-scalars:
    141    elif isinstance(obj, list):
    142        ret += 'QLIT_QLIST(((QLitObject[]) {\n'
    143        for value in obj:
    144            ret += _tree_to_qlit(value, level + 1).strip('\n') + '\n'
    145        ret += indent(level + 1) + '{}\n'
    146        ret += indent(level) + '}))'
    147    elif isinstance(obj, dict):
    148        ret += 'QLIT_QDICT(((QLitDictEntry[]) {\n'
    149        for key, value in sorted(obj.items()):
    150            ret += indent(level + 1) + "{{ {:s}, {:s} }},\n".format(
    151                to_c_string(key),
    152                _tree_to_qlit(value, level + 1, dict_value=True)
    153            )
    154        ret += indent(level + 1) + '{}\n'
    155        ret += indent(level) + '}))'
    156    else:
    157        raise NotImplementedError(
    158            f"type '{type(obj).__name__}' not implemented"
    159        )
    160
    161    if level > 0:
    162        ret += ','
    163    return ret
    164
    165
    166def to_c_string(string: str) -> str:
    167    return '"' + string.replace('\\', r'\\').replace('"', r'\"') + '"'
    168
    169
    170class QAPISchemaGenIntrospectVisitor(QAPISchemaMonolithicCVisitor):
    171
    172    def __init__(self, prefix: str, unmask: bool):
    173        super().__init__(
    174            prefix, 'qapi-introspect',
    175            ' * QAPI/QMP schema introspection', __doc__)
    176        self._unmask = unmask
    177        self._schema: Optional[QAPISchema] = None
    178        self._trees: List[Annotated[SchemaInfo]] = []
    179        self._used_types: List[QAPISchemaType] = []
    180        self._name_map: Dict[str, str] = {}
    181        self._genc.add(mcgen('''
    182#include "qemu/osdep.h"
    183#include "%(prefix)sqapi-introspect.h"
    184
    185''',
    186                             prefix=prefix))
    187
    188    def visit_begin(self, schema: QAPISchema) -> None:
    189        self._schema = schema
    190
    191    def visit_end(self) -> None:
    192        # visit the types that are actually used
    193        for typ in self._used_types:
    194            typ.visit(self)
    195        # generate C
    196        name = c_name(self._prefix, protect=False) + 'qmp_schema_qlit'
    197        self._genh.add(mcgen('''
    198#include "qapi/qmp/qlit.h"
    199
    200extern const QLitObject %(c_name)s;
    201''',
    202                             c_name=c_name(name)))
    203        self._genc.add(mcgen('''
    204const QLitObject %(c_name)s = %(c_string)s;
    205''',
    206                             c_name=c_name(name),
    207                             c_string=_tree_to_qlit(self._trees)))
    208        self._schema = None
    209        self._trees = []
    210        self._used_types = []
    211        self._name_map = {}
    212
    213    def visit_needed(self, entity: QAPISchemaEntity) -> bool:
    214        # Ignore types on first pass; visit_end() will pick up used types
    215        return not isinstance(entity, QAPISchemaType)
    216
    217    def _name(self, name: str) -> str:
    218        if self._unmask:
    219            return name
    220        if name not in self._name_map:
    221            self._name_map[name] = '%d' % len(self._name_map)
    222        return self._name_map[name]
    223
    224    def _use_type(self, typ: QAPISchemaType) -> str:
    225        assert self._schema is not None
    226
    227        # Map the various integer types to plain int
    228        if typ.json_type() == 'int':
    229            typ = self._schema.lookup_type('int')
    230        elif (isinstance(typ, QAPISchemaArrayType) and
    231              typ.element_type.json_type() == 'int'):
    232            typ = self._schema.lookup_type('intList')
    233        # Add type to work queue if new
    234        if typ not in self._used_types:
    235            self._used_types.append(typ)
    236        # Clients should examine commands and events, not types.  Hide
    237        # type names as integers to reduce the temptation.  Also, it
    238        # saves a few characters on the wire.
    239        if isinstance(typ, QAPISchemaBuiltinType):
    240            return typ.name
    241        if isinstance(typ, QAPISchemaArrayType):
    242            return '[' + self._use_type(typ.element_type) + ']'
    243        return self._name(typ.name)
    244
    245    @staticmethod
    246    def _gen_features(features: Sequence[QAPISchemaFeature]
    247                      ) -> List[Annotated[str]]:
    248        return [Annotated(f.name, f.ifcond) for f in features]
    249
    250    def _gen_tree(self, name: str, mtype: str, obj: Dict[str, object],
    251                  ifcond: QAPISchemaIfCond = QAPISchemaIfCond(),
    252                  features: Sequence[QAPISchemaFeature] = ()) -> None:
    253        """
    254        Build and append a SchemaInfo object to self._trees.
    255
    256        :param name: The SchemaInfo's name.
    257        :param mtype: The SchemaInfo's meta-type.
    258        :param obj: Additional SchemaInfo members, as appropriate for
    259                    the meta-type.
    260        :param ifcond: Conditionals to apply to the SchemaInfo.
    261        :param features: The SchemaInfo's features.
    262                         Will be omitted from the output if empty.
    263        """
    264        comment: Optional[str] = None
    265        if mtype not in ('command', 'event', 'builtin', 'array'):
    266            if not self._unmask:
    267                # Output a comment to make it easy to map masked names
    268                # back to the source when reading the generated output.
    269                comment = f'"{self._name(name)}" = {name}'
    270            name = self._name(name)
    271        obj['name'] = name
    272        obj['meta-type'] = mtype
    273        if features:
    274            obj['features'] = self._gen_features(features)
    275        self._trees.append(Annotated(obj, ifcond, comment))
    276
    277    def _gen_member(self, member: QAPISchemaObjectTypeMember
    278                    ) -> Annotated[SchemaInfoObjectMember]:
    279        obj: SchemaInfoObjectMember = {
    280            'name': member.name,
    281            'type': self._use_type(member.type)
    282        }
    283        if member.optional:
    284            obj['default'] = None
    285        if member.features:
    286            obj['features'] = self._gen_features(member.features)
    287        return Annotated(obj, member.ifcond)
    288
    289    def _gen_variant(self, variant: QAPISchemaVariant
    290                     ) -> Annotated[SchemaInfoObjectVariant]:
    291        obj: SchemaInfoObjectVariant = {
    292            'case': variant.name,
    293            'type': self._use_type(variant.type)
    294        }
    295        return Annotated(obj, variant.ifcond)
    296
    297    def visit_builtin_type(self, name: str, info: Optional[QAPISourceInfo],
    298                           json_type: str) -> None:
    299        self._gen_tree(name, 'builtin', {'json-type': json_type})
    300
    301    def visit_enum_type(self, name: str, info: Optional[QAPISourceInfo],
    302                        ifcond: QAPISchemaIfCond,
    303                        features: List[QAPISchemaFeature],
    304                        members: List[QAPISchemaEnumMember],
    305                        prefix: Optional[str]) -> None:
    306        self._gen_tree(
    307            name, 'enum',
    308            {'values': [Annotated(m.name, m.ifcond) for m in members]},
    309            ifcond, features
    310        )
    311
    312    def visit_array_type(self, name: str, info: Optional[QAPISourceInfo],
    313                         ifcond: QAPISchemaIfCond,
    314                         element_type: QAPISchemaType) -> None:
    315        element = self._use_type(element_type)
    316        self._gen_tree('[' + element + ']', 'array', {'element-type': element},
    317                       ifcond)
    318
    319    def visit_object_type_flat(self, name: str, info: Optional[QAPISourceInfo],
    320                               ifcond: QAPISchemaIfCond,
    321                               features: List[QAPISchemaFeature],
    322                               members: List[QAPISchemaObjectTypeMember],
    323                               variants: Optional[QAPISchemaVariants]) -> None:
    324        obj: SchemaInfoObject = {
    325            'members': [self._gen_member(m) for m in members]
    326        }
    327        if variants:
    328            obj['tag'] = variants.tag_member.name
    329            obj['variants'] = [self._gen_variant(v) for v in variants.variants]
    330        self._gen_tree(name, 'object', obj, ifcond, features)
    331
    332    def visit_alternate_type(self, name: str, info: Optional[QAPISourceInfo],
    333                             ifcond: QAPISchemaIfCond,
    334                             features: List[QAPISchemaFeature],
    335                             variants: QAPISchemaVariants) -> None:
    336        self._gen_tree(
    337            name, 'alternate',
    338            {'members': [Annotated({'type': self._use_type(m.type)},
    339                                   m.ifcond)
    340                         for m in variants.variants]},
    341            ifcond, features
    342        )
    343
    344    def visit_command(self, name: str, info: Optional[QAPISourceInfo],
    345                      ifcond: QAPISchemaIfCond,
    346                      features: List[QAPISchemaFeature],
    347                      arg_type: Optional[QAPISchemaObjectType],
    348                      ret_type: Optional[QAPISchemaType], gen: bool,
    349                      success_response: bool, boxed: bool, allow_oob: bool,
    350                      allow_preconfig: bool, coroutine: bool) -> None:
    351        assert self._schema is not None
    352
    353        arg_type = arg_type or self._schema.the_empty_object_type
    354        ret_type = ret_type or self._schema.the_empty_object_type
    355        obj: SchemaInfoCommand = {
    356            'arg-type': self._use_type(arg_type),
    357            'ret-type': self._use_type(ret_type)
    358        }
    359        if allow_oob:
    360            obj['allow-oob'] = allow_oob
    361        self._gen_tree(name, 'command', obj, ifcond, features)
    362
    363    def visit_event(self, name: str, info: Optional[QAPISourceInfo],
    364                    ifcond: QAPISchemaIfCond,
    365                    features: List[QAPISchemaFeature],
    366                    arg_type: Optional[QAPISchemaObjectType],
    367                    boxed: bool) -> None:
    368        assert self._schema is not None
    369
    370        arg_type = arg_type or self._schema.the_empty_object_type
    371        self._gen_tree(name, 'event', {'arg-type': self._use_type(arg_type)},
    372                       ifcond, features)
    373
    374
    375def gen_introspect(schema: QAPISchema, output_dir: str, prefix: str,
    376                   opt_unmask: bool) -> None:
    377    vis = QAPISchemaGenIntrospectVisitor(prefix, opt_unmask)
    378    schema.visit(vis)
    379    vis.write(output_dir)