Introduce Virtio-loopback epsilon release:

Epsilon release introduces a new compatibility layer which make virtio-loopback
design to work with QEMU and rust-vmm vhost-user backend without require any
changes.

Signed-off-by: Timos Ampelikiotis <t.ampelikiotis@virtualopensystems.com>
Change-Id: I52e57563e08a7d0bdc002f8e928ee61ba0c53dd9

1 files changed, 338 insertions, 0 deletions

diff --git a/scripts/qapi/commands.py b/scripts/qapi/commands.py
new file mode 100644
index 000000000..21001bbd6
--- /dev/null
+++ b/scripts/qapi/commands.py
@@ -0,0 +1,338 @@
+"""
+QAPI command marshaller generator
+
+Copyright IBM, Corp. 2011
+Copyright (C) 2014-2018 Red Hat, Inc.
+
+Authors:
+ Anthony Liguori <aliguori@us.ibm.com>
+ Michael Roth <mdroth@linux.vnet.ibm.com>
+ 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 typing import (
+    Dict,
+    List,
+    Optional,
+    Set,
+)
+
+from .common import c_name, mcgen
+from .gen import (
+    QAPIGenC,
+    QAPISchemaModularCVisitor,
+    build_params,
+    ifcontext,
+    gen_special_features,
+)
+from .schema import (
+    QAPISchema,
+    QAPISchemaFeature,
+    QAPISchemaIfCond,
+    QAPISchemaObjectType,
+    QAPISchemaType,
+)
+from .source import QAPISourceInfo
+
+
+def gen_command_decl(name: str,
+                     arg_type: Optional[QAPISchemaObjectType],
+                     boxed: bool,
+                     ret_type: Optional[QAPISchemaType]) -> str:
+    return mcgen('''
+%(c_type)s qmp_%(c_name)s(%(params)s);
+''',
+                 c_type=(ret_type and ret_type.c_type()) or 'void',
+                 c_name=c_name(name),
+                 params=build_params(arg_type, boxed, 'Error **errp'))
+
+
+def gen_call(name: str,
+             arg_type: Optional[QAPISchemaObjectType],
+             boxed: bool,
+             ret_type: Optional[QAPISchemaType]) -> str:
+    ret = ''
+
+    argstr = ''
+    if boxed:
+        assert arg_type
+        argstr = '&arg, '
+    elif arg_type:
+        assert not arg_type.variants
+        for memb in arg_type.members:
+            if memb.optional:
+                argstr += 'arg.has_%s, ' % c_name(memb.name)
+            argstr += 'arg.%s, ' % c_name(memb.name)
+
+    lhs = ''
+    if ret_type:
+        lhs = 'retval = '
+
+    ret = mcgen('''
+
+    %(lhs)sqmp_%(c_name)s(%(args)s&err);
+    error_propagate(errp, err);
+''',
+                c_name=c_name(name), args=argstr, lhs=lhs)
+    if ret_type:
+        ret += mcgen('''
+    if (err) {
+        goto out;
+    }
+
+    qmp_marshal_output_%(c_name)s(retval, ret, errp);
+''',
+                     c_name=ret_type.c_name())
+    return ret
+
+
+def gen_marshal_output(ret_type: QAPISchemaType) -> str:
+    return mcgen('''
+
+static void qmp_marshal_output_%(c_name)s(%(c_type)s ret_in,
+                                QObject **ret_out, Error **errp)
+{
+    Visitor *v;
+
+    v = qobject_output_visitor_new_qmp(ret_out);
+    if (visit_type_%(c_name)s(v, "unused", &ret_in, errp)) {
+        visit_complete(v, ret_out);
+    }
+    visit_free(v);
+    v = qapi_dealloc_visitor_new();
+    visit_type_%(c_name)s(v, "unused", &ret_in, NULL);
+    visit_free(v);
+}
+''',
+                 c_type=ret_type.c_type(), c_name=ret_type.c_name())
+
+
+def build_marshal_proto(name: str) -> str:
+    return ('void qmp_marshal_%s(QDict *args, QObject **ret, Error **errp)'
+            % c_name(name))
+
+
+def gen_marshal_decl(name: str) -> str:
+    return mcgen('''
+%(proto)s;
+''',
+                 proto=build_marshal_proto(name))
+
+
+def gen_marshal(name: str,
+                arg_type: Optional[QAPISchemaObjectType],
+                boxed: bool,
+                ret_type: Optional[QAPISchemaType]) -> str:
+    have_args = boxed or (arg_type and not arg_type.is_empty())
+    if have_args:
+        assert arg_type is not None
+        arg_type_c_name = arg_type.c_name()
+
+    ret = mcgen('''
+
+%(proto)s
+{
+    Error *err = NULL;
+    bool ok = false;
+    Visitor *v;
+''',
+                proto=build_marshal_proto(name))
+
+    if ret_type:
+        ret += mcgen('''
+    %(c_type)s retval;
+''',
+                     c_type=ret_type.c_type())
+
+    if have_args:
+        ret += mcgen('''
+    %(c_name)s arg = {0};
+''',
+                     c_name=arg_type_c_name)
+
+    ret += mcgen('''
+
+    v = qobject_input_visitor_new_qmp(QOBJECT(args));
+    if (!visit_start_struct(v, NULL, NULL, 0, errp)) {
+        goto out;
+    }
+''')
+
+    if have_args:
+        ret += mcgen('''
+    if (visit_type_%(c_arg_type)s_members(v, &arg, errp)) {
+        ok = visit_check_struct(v, errp);
+    }
+''',
+                     c_arg_type=arg_type_c_name)
+    else:
+        ret += mcgen('''
+    ok = visit_check_struct(v, errp);
+''')
+
+    ret += mcgen('''
+    visit_end_struct(v, NULL);
+    if (!ok) {
+        goto out;
+    }
+''')
+
+    ret += gen_call(name, arg_type, boxed, ret_type)
+
+    ret += mcgen('''
+
+out:
+    visit_free(v);
+''')
+
+    ret += mcgen('''
+    v = qapi_dealloc_visitor_new();
+    visit_start_struct(v, NULL, NULL, 0, NULL);
+''')
+
+    if have_args:
+        ret += mcgen('''
+    visit_type_%(c_arg_type)s_members(v, &arg, NULL);
+''',
+                     c_arg_type=arg_type_c_name)
+
+    ret += mcgen('''
+    visit_end_struct(v, NULL);
+    visit_free(v);
+''')
+
+    ret += mcgen('''
+}
+''')
+    return ret
+
+
+def gen_register_command(name: str,
+                         features: List[QAPISchemaFeature],
+                         success_response: bool,
+                         allow_oob: bool,
+                         allow_preconfig: bool,
+                         coroutine: bool) -> str:
+    options = []
+
+    if not success_response:
+        options += ['QCO_NO_SUCCESS_RESP']
+    if allow_oob:
+        options += ['QCO_ALLOW_OOB']
+    if allow_preconfig:
+        options += ['QCO_ALLOW_PRECONFIG']
+    if coroutine:
+        options += ['QCO_COROUTINE']
+
+    ret = mcgen('''
+    qmp_register_command(cmds, "%(name)s",
+                         qmp_marshal_%(c_name)s, %(opts)s, %(feats)s);
+''',
+                name=name, c_name=c_name(name),
+                opts=' | '.join(options) or 0,
+                feats=gen_special_features(features))
+    return ret
+
+
+class QAPISchemaGenCommandVisitor(QAPISchemaModularCVisitor):
+    def __init__(self, prefix: str):
+        super().__init__(
+            prefix, 'qapi-commands',
+            ' * Schema-defined QAPI/QMP commands', None, __doc__)
+        self._visited_ret_types: Dict[QAPIGenC, Set[QAPISchemaType]] = {}
+
+    def _begin_user_module(self, name: str) -> None:
+        self._visited_ret_types[self._genc] = set()
+        commands = self._module_basename('qapi-commands', name)
+        types = self._module_basename('qapi-types', name)
+        visit = self._module_basename('qapi-visit', name)
+        self._genc.add(mcgen('''
+#include "qemu/osdep.h"
+#include "qapi/compat-policy.h"
+#include "qapi/visitor.h"
+#include "qapi/qmp/qdict.h"
+#include "qapi/dealloc-visitor.h"
+#include "qapi/error.h"
+#include "%(visit)s.h"
+#include "%(commands)s.h"
+
+''',
+                             commands=commands, visit=visit))
+        self._genh.add(mcgen('''
+#include "%(types)s.h"
+
+''',
+                             types=types))
+
+    def visit_begin(self, schema: QAPISchema) -> None:
+        self._add_module('./init', ' * QAPI Commands initialization')
+        self._genh.add(mcgen('''
+#include "qapi/qmp/dispatch.h"
+
+void %(c_prefix)sqmp_init_marshal(QmpCommandList *cmds);
+''',
+                             c_prefix=c_name(self._prefix, protect=False)))
+        self._genc.add(mcgen('''
+#include "qemu/osdep.h"
+#include "%(prefix)sqapi-commands.h"
+#include "%(prefix)sqapi-init-commands.h"
+
+void %(c_prefix)sqmp_init_marshal(QmpCommandList *cmds)
+{
+    QTAILQ_INIT(cmds);
+
+''',
+                             prefix=self._prefix,
+                             c_prefix=c_name(self._prefix, protect=False)))
+
+    def visit_end(self) -> None:
+        with self._temp_module('./init'):
+            self._genc.add(mcgen('''
+}
+'''))
+
+    def visit_command(self,
+                      name: str,
+                      info: Optional[QAPISourceInfo],
+                      ifcond: QAPISchemaIfCond,
+                      features: List[QAPISchemaFeature],
+                      arg_type: Optional[QAPISchemaObjectType],
+                      ret_type: Optional[QAPISchemaType],
+                      gen: bool,
+                      success_response: bool,
+                      boxed: bool,
+                      allow_oob: bool,
+                      allow_preconfig: bool,
+                      coroutine: bool) -> None:
+        if not gen:
+            return
+        # FIXME: If T is a user-defined type, the user is responsible
+        # for making this work, i.e. to make T's condition the
+        # conjunction of the T-returning commands' conditions.  If T
+        # is a built-in type, this isn't possible: the
+        # qmp_marshal_output_T() will be generated unconditionally.
+        if ret_type and ret_type not in self._visited_ret_types[self._genc]:
+            self._visited_ret_types[self._genc].add(ret_type)
+            with ifcontext(ret_type.ifcond,
+                           self._genh, self._genc):
+                self._genc.add(gen_marshal_output(ret_type))
+        with ifcontext(ifcond, self._genh, self._genc):
+            self._genh.add(gen_command_decl(name, arg_type, boxed, ret_type))
+            self._genh.add(gen_marshal_decl(name))
+            self._genc.add(gen_marshal(name, arg_type, boxed, ret_type))
+        with self._temp_module('./init'):
+            with ifcontext(ifcond, self._genh, self._genc):
+                self._genc.add(gen_register_command(
+                    name, features, success_response, allow_oob,
+                    allow_preconfig, coroutine))
+
+
+def gen_commands(schema: QAPISchema,
+                 output_dir: str,
+                 prefix: str) -> None:
+    vis = QAPISchemaGenCommandVisitor(prefix)
+    schema.visit(vis)
+    vis.write(output_dir)