import

qemu/qapi/Makefile.objs

@@ -0,0 +1,3 @@
+util-obj-y = qapi-visit-core.o qapi-dealloc-visitor.o qmp-input-visitor.o
+util-obj-y += qmp-output-visitor.o
+util-obj-y += string-input-visitor.o string-output-visitor.o

qemu/qapi/common.json

@@ -0,0 +1,30 @@
+# -*- Mode: Python -*-
+#
+# QAPI common definitions
+
+##
+# @ErrorClass
+#
+# QEMU error classes
+#
+# @GenericError: this is used for errors that don't require a specific error
+#                class. This should be the default case for most errors
+#
+# @CommandNotFound: the requested command has not been found
+#
+# @DeviceEncrypted: the requested operation can't be fulfilled because the
+#                   selected device is encrypted
+#
+# @DeviceNotActive: a device has failed to be become active
+#
+# @DeviceNotFound: the requested device has not been found
+#
+# @KVMMissingCap: the requested operation can't be fulfilled because a
+#                 required KVM capability is missing
+#
+# Since: 1.2
+##
+{ 'enum': 'ErrorClass',
+  'data': [ 'GenericError', 'CommandNotFound', 'DeviceEncrypted',
+            'DeviceNotActive', 'DeviceNotFound', 'KVMMissingCap' ] }
+

qemu/qapi/qapi-dealloc-visitor.c

@@ -0,0 +1,224 @@
+/*
+ * Dealloc Visitor
+ *
+ * Copyright IBM, Corp. 2011
+ *
+ * Authors:
+ *  Michael Roth   <mdroth@linux.vnet.ibm.com>
+ *
+ * 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.
+ *
+ */
+
+#include "qapi/dealloc-visitor.h"
+#include "qemu/queue.h"
+#include "qemu-common.h"
+#include "qapi/qmp/types.h"
+#include "qapi/visitor-impl.h"
+
+typedef struct StackEntry
+{
+    void *value;
+    bool is_list_head;
+    QTAILQ_ENTRY(StackEntry) node;
+} StackEntry;
+
+struct QapiDeallocVisitor
+{
+    Visitor visitor;
+    QTAILQ_HEAD(, StackEntry) stack;
+    bool is_list_head;
+};
+
+static QapiDeallocVisitor *to_qov(Visitor *v)
+{
+    return container_of(v, QapiDeallocVisitor, visitor);
+}
+
+static void qapi_dealloc_push(QapiDeallocVisitor *qov, void *value)
+{
+    StackEntry *e = g_malloc0(sizeof(*e));
+
+    e->value = value;
+
+    /* see if we're just pushing a list head tracker */
+    if (value == NULL) {
+        e->is_list_head = true;
+    }
+    QTAILQ_INSERT_HEAD(&qov->stack, e, node);
+}
+
+static void *qapi_dealloc_pop(QapiDeallocVisitor *qov)
+{
+    StackEntry *e = QTAILQ_FIRST(&qov->stack);
+    QObject *value;
+    QTAILQ_REMOVE(&qov->stack, e, node);
+    value = e->value;
+    g_free(e);
+    return value;
+}
+
+static void qapi_dealloc_start_struct(Visitor *v, void **obj, const char *kind,
+                                      const char *name, size_t unused,
+                                      Error **errp)
+{
+    QapiDeallocVisitor *qov = to_qov(v);
+    qapi_dealloc_push(qov, obj);
+}
+
+static void qapi_dealloc_end_struct(Visitor *v, Error **errp)
+{
+    QapiDeallocVisitor *qov = to_qov(v);
+    void **obj = qapi_dealloc_pop(qov);
+    if (obj) {
+        g_free(*obj);
+    }
+}
+
+static void qapi_dealloc_start_implicit_struct(Visitor *v,
+                                               void **obj,
+                                               size_t size,
+                                               Error **errp)
+{
+    QapiDeallocVisitor *qov = to_qov(v);
+    qapi_dealloc_push(qov, obj);
+}
+
+static void qapi_dealloc_end_implicit_struct(Visitor *v, Error **errp)
+{
+    QapiDeallocVisitor *qov = to_qov(v);
+    void **obj = qapi_dealloc_pop(qov);
+    if (obj) {
+        g_free(*obj);
+    }
+}
+
+static void qapi_dealloc_start_list(Visitor *v, const char *name, Error **errp)
+{
+    QapiDeallocVisitor *qov = to_qov(v);
+    qapi_dealloc_push(qov, NULL);
+}
+
+static GenericList *qapi_dealloc_next_list(Visitor *v, GenericList **listp,
+                                           Error **errp)
+{
+    GenericList *list = *listp;
+    QapiDeallocVisitor *qov = to_qov(v);
+    StackEntry *e = QTAILQ_FIRST(&qov->stack);
+
+    if (e && e->is_list_head) {
+        e->is_list_head = false;
+        return list;
+    }
+
+    if (list) {
+        list = list->next;
+        g_free(*listp);
+        return list;
+    }
+
+    return NULL;
+}
+
+static void qapi_dealloc_end_list(Visitor *v, Error **errp)
+{
+    QapiDeallocVisitor *qov = to_qov(v);
+    void *obj = qapi_dealloc_pop(qov);
+    assert(obj == NULL); /* should've been list head tracker with no payload */
+}
+
+static void qapi_dealloc_type_str(Visitor *v, char **obj, const char *name,
+                                  Error **errp)
+{
+    if (obj) {
+        g_free(*obj);
+    }
+}
+
+static void qapi_dealloc_type_int(Visitor *v, int64_t *obj, const char *name,
+                                  Error **errp)
+{
+}
+
+static void qapi_dealloc_type_bool(Visitor *v, bool *obj, const char *name,
+                                   Error **errp)
+{
+}
+
+static void qapi_dealloc_type_number(Visitor *v, double *obj, const char *name,
+                                     Error **errp)
+{
+}
+
+static void qapi_dealloc_type_size(Visitor *v, uint64_t *obj, const char *name,
+                                   Error **errp)
+{
+}
+
+static void qapi_dealloc_type_enum(Visitor *v, int *obj, const char *strings[],
+                                   const char *kind, const char *name,
+                                   Error **errp)
+{
+}
+
+/* If there's no data present, the dealloc visitor has nothing to free.
+ * Thus, indicate to visitor code that the subsequent union fields can
+ * be skipped. This is not an error condition, since the cleanup of the
+ * rest of an object can continue unhindered, so leave errp unset in
+ * these cases.
+ *
+ * NOTE: In cases where we're attempting to deallocate an object that
+ * may have missing fields, the field indicating the union type may
+ * be missing. In such a case, it's possible we don't have enough
+ * information to differentiate data_present == false from a case where
+ * data *is* present but happens to be a scalar with a value of 0.
+ * This is okay, since in the case of the dealloc visitor there's no
+ * work that needs to done in either situation.
+ *
+ * The current inability in QAPI code to more thoroughly verify a union
+ * type in such cases will likely need to be addressed if we wish to
+ * implement this interface for other types of visitors in the future,
+ * however.
+ */
+static bool qapi_dealloc_start_union(Visitor *v, bool data_present,
+                                     Error **errp)
+{
+    return data_present;
+}
+
+Visitor *qapi_dealloc_get_visitor(QapiDeallocVisitor *v)
+{
+    return &v->visitor;
+}
+
+void qapi_dealloc_visitor_cleanup(QapiDeallocVisitor *v)
+{
+    g_free(v);
+}
+
+QapiDeallocVisitor *qapi_dealloc_visitor_new(void)
+{
+    QapiDeallocVisitor *v;
+
+    v = g_malloc0(sizeof(*v));
+
+    v->visitor.start_struct = qapi_dealloc_start_struct;
+    v->visitor.end_struct = qapi_dealloc_end_struct;
+    v->visitor.start_implicit_struct = qapi_dealloc_start_implicit_struct;
+    v->visitor.end_implicit_struct = qapi_dealloc_end_implicit_struct;
+    v->visitor.start_list = qapi_dealloc_start_list;
+    v->visitor.next_list = qapi_dealloc_next_list;
+    v->visitor.end_list = qapi_dealloc_end_list;
+    v->visitor.type_enum = qapi_dealloc_type_enum;
+    v->visitor.type_int = qapi_dealloc_type_int;
+    v->visitor.type_bool = qapi_dealloc_type_bool;
+    v->visitor.type_str = qapi_dealloc_type_str;
+    v->visitor.type_number = qapi_dealloc_type_number;
+    v->visitor.type_size = qapi_dealloc_type_size;
+    v->visitor.start_union = qapi_dealloc_start_union;
+
+    QTAILQ_INIT(&v->stack);
+
+    return v;
+}

qemu/qapi/qapi-visit-core.c

@@ -0,0 +1,313 @@
+/*
+ * Core Definitions for QAPI Visitor Classes
+ *
+ * Copyright IBM, Corp. 2011
+ *
+ * Authors:
+ *  Anthony Liguori   <aliguori@us.ibm.com>
+ *
+ * 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.
+ *
+ */
+
+#include "qemu-common.h"
+#include "qapi/qmp/qobject.h"
+#include "qapi/qmp/qerror.h"
+#include "qapi/visitor.h"
+#include "qapi/visitor-impl.h"
+
+void visit_start_struct(Visitor *v, void **obj, const char *kind,
+                        const char *name, size_t size, Error **errp)
+{
+    v->start_struct(v, obj, kind, name, size, errp);
+}
+
+void visit_end_struct(Visitor *v, Error **errp)
+{
+    v->end_struct(v, errp);
+}
+
+void visit_start_implicit_struct(Visitor *v, void **obj, size_t size,
+                                 Error **errp)
+{
+    if (v->start_implicit_struct) {
+        v->start_implicit_struct(v, obj, size, errp);
+    }
+}
+
+void visit_end_implicit_struct(Visitor *v, Error **errp)
+{
+    if (v->end_implicit_struct) {
+        v->end_implicit_struct(v, errp);
+    }
+}
+
+void visit_start_list(Visitor *v, const char *name, Error **errp)
+{
+    v->start_list(v, name, errp);
+}
+
+GenericList *visit_next_list(Visitor *v, GenericList **list, Error **errp)
+{
+    return v->next_list(v, list, errp);
+}
+
+void visit_end_list(Visitor *v, Error **errp)
+{
+    v->end_list(v, errp);
+}
+
+bool visit_start_union(Visitor *v, bool data_present, Error **errp)
+{
+    if (v->start_union) {
+        return v->start_union(v, data_present, errp);
+    }
+    return true;
+}
+
+void visit_end_union(Visitor *v, bool data_present, Error **errp)
+{
+    if (v->end_union) {
+        v->end_union(v, data_present, errp);
+    }
+}
+
+void visit_optional(Visitor *v, bool *present, const char *name,
+                    Error **errp)
+{
+    if (v->optional) {
+        v->optional(v, present, name, errp);
+    }
+}
+
+void visit_get_next_type(Visitor *v, int *obj, const int *qtypes,
+                         const char *name, Error **errp)
+{
+    if (v->get_next_type) {
+        v->get_next_type(v, obj, qtypes, name, errp);
+    }
+}
+
+void visit_type_enum(Visitor *v, int *obj, const char *strings[],
+                     const char *kind, const char *name, Error **errp)
+{
+    v->type_enum(v, obj, strings, kind, name, errp);
+}
+
+void visit_type_int(Visitor *v, int64_t *obj, const char *name, Error **errp)
+{
+    v->type_int(v, obj, name, errp);
+}
+
+void visit_type_uint8(Visitor *v, uint8_t *obj, const char *name, Error **errp)
+{
+    int64_t value;
+
+    if (v->type_uint8) {
+        v->type_uint8(v, obj, name, errp);
+    } else {
+        value = *obj;
+        v->type_int(v, &value, name, errp);
+        if (value < 0 || value > UINT8_MAX) {
+            error_set(errp, QERR_INVALID_PARAMETER_VALUE, name ? name : "null",
+                      "uint8_t");
+            return;
+        }
+        *obj = value;
+    }
+}
+
+void visit_type_uint16(Visitor *v, uint16_t *obj, const char *name, Error **errp)
+{
+    int64_t value;
+
+    if (v->type_uint16) {
+        v->type_uint16(v, obj, name, errp);
+    } else {
+        value = *obj;
+        v->type_int(v, &value, name, errp);
+        if (value < 0 || value > UINT16_MAX) {
+            error_set(errp, QERR_INVALID_PARAMETER_VALUE, name ? name : "null",
+                      "uint16_t");
+            return;
+        }
+        *obj = value;
+    }
+}
+
+void visit_type_uint32(Visitor *v, uint32_t *obj, const char *name, Error **errp)
+{
+    int64_t value;
+
+    if (v->type_uint32) {
+        v->type_uint32(v, obj, name, errp);
+    } else {
+        value = *obj;
+        v->type_int(v, &value, name, errp);
+        if (value < 0 || value > UINT32_MAX) {
+            error_set(errp, QERR_INVALID_PARAMETER_VALUE, name ? name : "null",
+                      "uint32_t");
+            return;
+        }
+        *obj = value;
+    }
+}
+
+void visit_type_uint64(Visitor *v, uint64_t *obj, const char *name, Error **errp)
+{
+    int64_t value;
+
+    if (v->type_uint64) {
+        v->type_uint64(v, obj, name, errp);
+    } else {
+        value = *obj;
+        v->type_int(v, &value, name, errp);
+        *obj = value;
+    }
+}
+
+void visit_type_int8(Visitor *v, int8_t *obj, const char *name, Error **errp)
+{
+    int64_t value;
+
+    if (v->type_int8) {
+        v->type_int8(v, obj, name, errp);
+    } else {
+        value = *obj;
+        v->type_int(v, &value, name, errp);
+        if (value < INT8_MIN || value > INT8_MAX) {
+            error_set(errp, QERR_INVALID_PARAMETER_VALUE, name ? name : "null",
+                      "int8_t");
+            return;
+        }
+        *obj = value;
+    }
+}
+
+void visit_type_int16(Visitor *v, int16_t *obj, const char *name, Error **errp)
+{
+    int64_t value;
+
+    if (v->type_int16) {
+        v->type_int16(v, obj, name, errp);
+    } else {
+        value = *obj;
+        v->type_int(v, &value, name, errp);
+        if (value < INT16_MIN || value > INT16_MAX) {
+            error_set(errp, QERR_INVALID_PARAMETER_VALUE, name ? name : "null",
+                      "int16_t");
+            return;
+        }
+        *obj = value;
+    }
+}
+
+void visit_type_int32(Visitor *v, int32_t *obj, const char *name, Error **errp)
+{
+    int64_t value;
+
+    if (v->type_int32) {
+        v->type_int32(v, obj, name, errp);
+    } else {
+        value = *obj;
+        v->type_int(v, &value, name, errp);
+        if (value < INT32_MIN || value > INT32_MAX) {
+            error_set(errp, QERR_INVALID_PARAMETER_VALUE, name ? name : "null",
+                      "int32_t");
+            return;
+        }
+        *obj = value;
+    }
+}
+
+void visit_type_int64(Visitor *v, int64_t *obj, const char *name, Error **errp)
+{
+    if (v->type_int64) {
+        v->type_int64(v, obj, name, errp);
+    } else {
+        v->type_int(v, obj, name, errp);
+    }
+}
+
+void visit_type_size(Visitor *v, uint64_t *obj, const char *name, Error **errp)
+{
+    int64_t value;
+
+    if (v->type_size) {
+        v->type_size(v, obj, name, errp);
+    } else if (v->type_uint64) {
+        v->type_uint64(v, obj, name, errp);
+    } else {
+        value = *obj;
+        v->type_int(v, &value, name, errp);
+        *obj = value;
+    }
+}
+
+void visit_type_bool(Visitor *v, bool *obj, const char *name, Error **errp)
+{
+    v->type_bool(v, obj, name, errp);
+}
+
+void visit_type_str(Visitor *v, char **obj, const char *name, Error **errp)
+{
+    v->type_str(v, obj, name, errp);
+}
+
+void visit_type_number(Visitor *v, double *obj, const char *name, Error **errp)
+{
+    v->type_number(v, obj, name, errp);
+}
+
+void output_type_enum(Visitor *v, int *obj, const char *strings[],
+                      const char *kind, const char *name,
+                      Error **errp)
+{
+    int i = 0;
+    int value = *obj;
+    char *enum_str;
+
+    assert(strings);
+    while (strings[i++] != NULL);
+    if (value < 0 || value >= i - 1) {
+        error_set(errp, QERR_INVALID_PARAMETER, name ? name : "null");
+        return;
+    }
+
+    enum_str = (char *)strings[value];
+    visit_type_str(v, &enum_str, name, errp);
+}
+
+void input_type_enum(Visitor *v, int *obj, const char *strings[],
+                     const char *kind, const char *name,
+                     Error **errp)
+{
+    Error *local_err = NULL;
+    int64_t value = 0;
+    char *enum_str;
+
+    assert(strings);
+
+    visit_type_str(v, &enum_str, name, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        return;
+    }
+
+    while (strings[value] != NULL) {
+        if (strcmp(strings[value], enum_str) == 0) {
+            break;
+        }
+        value++;
+    }
+
+    if (strings[value] == NULL) {
+        error_set(errp, QERR_INVALID_PARAMETER, enum_str);
+        g_free(enum_str);
+        return;
+    }
+
+    g_free(enum_str);
+    *obj = value;
+}

qemu/qapi/qmp-input-visitor.c

@@ -0,0 +1,349 @@
+/*
+ * Input Visitor
+ *
+ * Copyright IBM, Corp. 2011
+ *
+ * Authors:
+ *  Anthony Liguori   <aliguori@us.ibm.com>
+ *
+ * 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.
+ *
+ */
+
+#include "qapi/qmp-input-visitor.h"
+#include "qapi/visitor-impl.h"
+#include "qemu/queue.h"
+#include "qemu-common.h"
+#include "qapi/qmp/types.h"
+#include "qapi/qmp/qerror.h"
+
+#define QIV_STACK_SIZE 1024
+
+typedef struct StackObject
+{
+    QObject *obj;
+    const QListEntry *entry;
+    GHashTable *h;
+} StackObject;
+
+struct QmpInputVisitor
+{
+    Visitor visitor;
+    StackObject stack[QIV_STACK_SIZE];
+    int nb_stack;
+    bool strict;
+};
+
+static QmpInputVisitor *to_qiv(Visitor *v)
+{
+    return container_of(v, QmpInputVisitor, visitor);
+}
+
+static QObject *qmp_input_get_object(QmpInputVisitor *qiv,
+                                     const char *name,
+                                     bool consume)
+{
+    QObject *qobj = qiv->stack[qiv->nb_stack - 1].obj;
+
+    if (qobj) {
+        if (name && qobject_type(qobj) == QTYPE_QDICT) {
+            if (qiv->stack[qiv->nb_stack - 1].h && consume) {
+                g_hash_table_remove(qiv->stack[qiv->nb_stack - 1].h, name);
+            }
+            return qdict_get(qobject_to_qdict(qobj), name);
+        } else if (qiv->stack[qiv->nb_stack - 1].entry) {
+            return qlist_entry_obj(qiv->stack[qiv->nb_stack - 1].entry);
+        }
+    }
+
+    return qobj;
+}
+
+static void qdict_add_key(const char *key, QObject *obj, void *opaque)
+{
+    GHashTable *h = opaque;
+    g_hash_table_insert(h, (gpointer) key, NULL);
+}
+
+static void qmp_input_push(QmpInputVisitor *qiv, QObject *obj, Error **errp)
+{
+    GHashTable *h;
+
+    if (qiv->nb_stack >= QIV_STACK_SIZE) {
+        error_setg(errp, "An internal buffer overran");
+        return;
+    }
+
+    qiv->stack[qiv->nb_stack].obj = obj;
+    qiv->stack[qiv->nb_stack].entry = NULL;
+    qiv->stack[qiv->nb_stack].h = NULL;
+
+    if (qiv->strict && qobject_type(obj) == QTYPE_QDICT) {
+        h = g_hash_table_new(g_str_hash, g_str_equal);
+        qdict_iter(qobject_to_qdict(obj), qdict_add_key, h);
+        qiv->stack[qiv->nb_stack].h = h;
+    }
+
+    qiv->nb_stack++;
+}
+
+/** Only for qmp_input_pop. */
+static gboolean always_true(gpointer key, gpointer val, gpointer user_pkey)
+{
+    *(const char **)user_pkey = (const char *)key;
+    return TRUE;
+}
+
+static void qmp_input_pop(QmpInputVisitor *qiv, Error **errp)
+{
+    assert(qiv->nb_stack > 0);
+
+    if (qiv->strict) {
+        GHashTable * const top_ht = qiv->stack[qiv->nb_stack - 1].h;
+        if (top_ht) {
+            if (g_hash_table_size(top_ht)) {
+                const char *key;
+                g_hash_table_find(top_ht, always_true, &key);
+                error_set(errp, QERR_QMP_EXTRA_MEMBER, key);
+            }
+            g_hash_table_unref(top_ht);
+        }
+    }
+
+    qiv->nb_stack--;
+}
+
+static void qmp_input_start_struct(Visitor *v, void **obj, const char *kind,
+                                   const char *name, size_t size, Error **errp)
+{
+    QmpInputVisitor *qiv = to_qiv(v);
+    QObject *qobj = qmp_input_get_object(qiv, name, true);
+    Error *err = NULL;
+
+    if (!qobj || qobject_type(qobj) != QTYPE_QDICT) {
+        error_set(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
+                  "QDict");
+        return;
+    }
+
+    qmp_input_push(qiv, qobj, &err);
+    if (err) {
+        error_propagate(errp, err);
+        return;
+    }
+
+    if (obj) {
+        *obj = g_malloc0(size);
+    }
+}
+
+static void qmp_input_end_struct(Visitor *v, Error **errp)
+{
+    QmpInputVisitor *qiv = to_qiv(v);
+
+    qmp_input_pop(qiv, errp);
+}
+
+static void qmp_input_start_implicit_struct(Visitor *v, void **obj,
+                                            size_t size, Error **errp)
+{
+    if (obj) {
+        *obj = g_malloc0(size);
+    }
+}
+
+static void qmp_input_end_implicit_struct(Visitor *v, Error **errp)
+{
+}
+
+static void qmp_input_start_list(Visitor *v, const char *name, Error **errp)
+{
+    QmpInputVisitor *qiv = to_qiv(v);
+    QObject *qobj = qmp_input_get_object(qiv, name, true);
+
+    if (!qobj || qobject_type(qobj) != QTYPE_QLIST) {
+        error_set(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
+                  "list");
+        return;
+    }
+
+    qmp_input_push(qiv, qobj, errp);
+}
+
+static GenericList *qmp_input_next_list(Visitor *v, GenericList **list,
+                                        Error **errp)
+{
+    QmpInputVisitor *qiv = to_qiv(v);
+    GenericList *entry;
+    StackObject *so = &qiv->stack[qiv->nb_stack - 1];
+    bool first;
+
+    if (so->entry == NULL) {
+        so->entry = qlist_first(qobject_to_qlist(so->obj));
+        first = true;
+    } else {
+        so->entry = qlist_next(so->entry);
+        first = false;
+    }
+
+    if (so->entry == NULL) {
+        return NULL;
+    }
+
+    entry = g_malloc0(sizeof(*entry));
+    if (first) {
+        *list = entry;
+    } else {
+        (*list)->next = entry;
+    }
+
+    return entry;
+}
+
+static void qmp_input_end_list(Visitor *v, Error **errp)
+{
+    QmpInputVisitor *qiv = to_qiv(v);
+
+    qmp_input_pop(qiv, errp);
+}
+
+static void qmp_input_get_next_type(Visitor *v, int *kind, const int *qobjects,
+                                    const char *name, Error **errp)
+{
+    QmpInputVisitor *qiv = to_qiv(v);
+    QObject *qobj = qmp_input_get_object(qiv, name, false);
+
+    if (!qobj) {
+        error_set(errp, QERR_MISSING_PARAMETER, name ? name : "null");
+        return;
+    }
+    *kind = qobjects[qobject_type(qobj)];
+}
+
+static void qmp_input_type_int(Visitor *v, int64_t *obj, const char *name,
+                               Error **errp)
+{
+    QmpInputVisitor *qiv = to_qiv(v);
+    QObject *qobj = qmp_input_get_object(qiv, name, true);
+
+    if (!qobj || qobject_type(qobj) != QTYPE_QINT) {
+        error_set(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
+                  "integer");
+        return;
+    }
+
+    *obj = qint_get_int(qobject_to_qint(qobj));
+}
+
+static void qmp_input_type_bool(Visitor *v, bool *obj, const char *name,
+                                Error **errp)
+{
+    QmpInputVisitor *qiv = to_qiv(v);
+    QObject *qobj = qmp_input_get_object(qiv, name, true);
+
+    if (!qobj || qobject_type(qobj) != QTYPE_QBOOL) {
+        error_set(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
+                  "boolean");
+        return;
+    }
+
+    *obj = qbool_get_int(qobject_to_qbool(qobj));
+}
+
+static void qmp_input_type_str(Visitor *v, char **obj, const char *name,
+                               Error **errp)
+{
+    QmpInputVisitor *qiv = to_qiv(v);
+    QObject *qobj = qmp_input_get_object(qiv, name, true);
+
+    if (!qobj || qobject_type(qobj) != QTYPE_QSTRING) {
+        error_set(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
+                  "string");
+        return;
+    }
+
+    *obj = g_strdup(qstring_get_str(qobject_to_qstring(qobj)));
+}
+
+static void qmp_input_type_number(Visitor *v, double *obj, const char *name,
+                                  Error **errp)
+{
+    QmpInputVisitor *qiv = to_qiv(v);
+    QObject *qobj = qmp_input_get_object(qiv, name, true);
+
+    if (!qobj || (qobject_type(qobj) != QTYPE_QFLOAT &&
+        qobject_type(qobj) != QTYPE_QINT)) {
+        error_set(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
+                  "number");
+        return;
+    }
+
+    if (qobject_type(qobj) == QTYPE_QINT) {
+        *obj = qint_get_int(qobject_to_qint(qobj));
+    } else {
+        *obj = qfloat_get_double(qobject_to_qfloat(qobj));
+    }
+}
+
+static void qmp_input_optional(Visitor *v, bool *present, const char *name,
+                               Error **errp)
+{
+    QmpInputVisitor *qiv = to_qiv(v);
+    QObject *qobj = qmp_input_get_object(qiv, name, true);
+
+    if (!qobj) {
+        *present = false;
+        return;
+    }
+
+    *present = true;
+}
+
+Visitor *qmp_input_get_visitor(QmpInputVisitor *v)
+{
+    return &v->visitor;
+}
+
+void qmp_input_visitor_cleanup(QmpInputVisitor *v)
+{
+    qobject_decref(v->stack[0].obj);
+    g_free(v);
+}
+
+QmpInputVisitor *qmp_input_visitor_new(QObject *obj)
+{
+    QmpInputVisitor *v;
+
+    v = g_malloc0(sizeof(*v));
+
+    v->visitor.start_struct = qmp_input_start_struct;
+    v->visitor.end_struct = qmp_input_end_struct;
+    v->visitor.start_implicit_struct = qmp_input_start_implicit_struct;
+    v->visitor.end_implicit_struct = qmp_input_end_implicit_struct;
+    v->visitor.start_list = qmp_input_start_list;
+    v->visitor.next_list = qmp_input_next_list;
+    v->visitor.end_list = qmp_input_end_list;
+    v->visitor.type_enum = input_type_enum;
+    v->visitor.type_int = qmp_input_type_int;
+    v->visitor.type_bool = qmp_input_type_bool;
+    v->visitor.type_str = qmp_input_type_str;
+    v->visitor.type_number = qmp_input_type_number;
+    v->visitor.optional = qmp_input_optional;
+    v->visitor.get_next_type = qmp_input_get_next_type;
+
+    qmp_input_push(v, obj, NULL);
+    qobject_incref(obj);
+
+    return v;
+}
+
+QmpInputVisitor *qmp_input_visitor_new_strict(QObject *obj)
+{
+    QmpInputVisitor *v;
+
+    v = qmp_input_visitor_new(obj);
+    v->strict = true;
+
+    return v;
+}

qemu/qapi/qmp-output-visitor.c

@@ -0,0 +1,241 @@
+/*
+ * Core Definitions for QAPI/QMP Command Registry
+ *
+ * Copyright IBM, Corp. 2011
+ *
+ * Authors:
+ *  Anthony Liguori   <aliguori@us.ibm.com>
+ *
+ * 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.
+ *
+ */
+
+#include "qapi/qmp-output-visitor.h"
+#include "qapi/visitor-impl.h"
+#include "qemu/queue.h"
+#include "qemu-common.h"
+#include "qapi/qmp/types.h"
+#include "qapi/qmp/qerror.h"
+
+typedef struct QStackEntry
+{
+    QObject *value;
+    bool is_list_head;
+    QTAILQ_ENTRY(QStackEntry) node;
+} QStackEntry;
+
+typedef QTAILQ_HEAD(QStack, QStackEntry) QStack;
+
+struct QmpOutputVisitor
+{
+    Visitor visitor;
+    QStack stack;
+};
+
+#define qmp_output_add(qov, name, value) \
+    qmp_output_add_obj(qov, name, QOBJECT(value))
+#define qmp_output_push(qov, value) qmp_output_push_obj(qov, QOBJECT(value))
+
+static QmpOutputVisitor *to_qov(Visitor *v)
+{
+    return container_of(v, QmpOutputVisitor, visitor);
+}
+
+static void qmp_output_push_obj(QmpOutputVisitor *qov, QObject *value)
+{
+    QStackEntry *e = g_malloc0(sizeof(*e));
+
+    e->value = value;
+    if (qobject_type(e->value) == QTYPE_QLIST) {
+        e->is_list_head = true;
+    }
+    QTAILQ_INSERT_HEAD(&qov->stack, e, node);
+}
+
+static QObject *qmp_output_pop(QmpOutputVisitor *qov)
+{
+    QStackEntry *e = QTAILQ_FIRST(&qov->stack);
+    QObject *value;
+    QTAILQ_REMOVE(&qov->stack, e, node);
+    value = e->value;
+    g_free(e);
+    return value;
+}
+
+static QObject *qmp_output_first(QmpOutputVisitor *qov)
+{
+    QStackEntry *e = QTAILQ_LAST(&qov->stack, QStack);
+
+    /* FIXME - find a better way to deal with NULL values */
+    if (!e) {
+        return NULL;
+    }
+
+    return e->value;
+}
+
+static QObject *qmp_output_last(QmpOutputVisitor *qov)
+{
+    QStackEntry *e = QTAILQ_FIRST(&qov->stack);
+    return e->value;
+}
+
+static void qmp_output_add_obj(QmpOutputVisitor *qov, const char *name,
+                               QObject *value)
+{
+    QObject *cur;
+
+    if (QTAILQ_EMPTY(&qov->stack)) {
+        qmp_output_push_obj(qov, value);
+        return;
+    }
+
+    cur = qmp_output_last(qov);
+
+    switch (qobject_type(cur)) {
+    case QTYPE_QDICT:
+        qdict_put_obj(qobject_to_qdict(cur), name, value);
+        break;
+    case QTYPE_QLIST:
+        qlist_append_obj(qobject_to_qlist(cur), value);
+        break;
+    default:
+        qobject_decref(qmp_output_pop(qov));
+        qmp_output_push_obj(qov, value);
+        break;
+    }
+}
+
+static void qmp_output_start_struct(Visitor *v, void **obj, const char *kind,
+                                    const char *name, size_t unused,
+                                    Error **errp)
+{
+    QmpOutputVisitor *qov = to_qov(v);
+    QDict *dict = qdict_new();
+
+    qmp_output_add(qov, name, dict);
+    qmp_output_push(qov, dict);
+}
+
+static void qmp_output_end_struct(Visitor *v, Error **errp)
+{
+    QmpOutputVisitor *qov = to_qov(v);
+    qmp_output_pop(qov);
+}
+
+static void qmp_output_start_list(Visitor *v, const char *name, Error **errp)
+{
+    QmpOutputVisitor *qov = to_qov(v);
+    QList *list = qlist_new();
+
+    qmp_output_add(qov, name, list);
+    qmp_output_push(qov, list);
+}
+
+static GenericList *qmp_output_next_list(Visitor *v, GenericList **listp,
+                                         Error **errp)
+{
+    GenericList *list = *listp;
+    QmpOutputVisitor *qov = to_qov(v);
+    QStackEntry *e = QTAILQ_FIRST(&qov->stack);
+
+    assert(e);
+    if (e->is_list_head) {
+        e->is_list_head = false;
+        return list;
+    }
+
+    return list ? list->next : NULL;
+}
+
+static void qmp_output_end_list(Visitor *v, Error **errp)
+{
+    QmpOutputVisitor *qov = to_qov(v);
+    qmp_output_pop(qov);
+}
+
+static void qmp_output_type_int(Visitor *v, int64_t *obj, const char *name,
+                                Error **errp)
+{
+    QmpOutputVisitor *qov = to_qov(v);
+    qmp_output_add(qov, name, qint_from_int(*obj));
+}
+
+static void qmp_output_type_bool(Visitor *v, bool *obj, const char *name,
+                                 Error **errp)
+{
+    QmpOutputVisitor *qov = to_qov(v);
+    qmp_output_add(qov, name, qbool_from_int(*obj));
+}
+
+static void qmp_output_type_str(Visitor *v, char **obj, const char *name,
+                                Error **errp)
+{
+    QmpOutputVisitor *qov = to_qov(v);
+    if (*obj) {
+        qmp_output_add(qov, name, qstring_from_str(*obj));
+    } else {
+        qmp_output_add(qov, name, qstring_from_str(""));
+    }
+}
+
+static void qmp_output_type_number(Visitor *v, double *obj, const char *name,
+                                   Error **errp)
+{
+    QmpOutputVisitor *qov = to_qov(v);
+    qmp_output_add(qov, name, qfloat_from_double(*obj));
+}
+
+QObject *qmp_output_get_qobject(QmpOutputVisitor *qov)
+{
+    QObject *obj = qmp_output_first(qov);
+    if (obj) {
+        qobject_incref(obj);
+    }
+    return obj;
+}
+
+Visitor *qmp_output_get_visitor(QmpOutputVisitor *v)
+{
+    return &v->visitor;
+}
+
+void qmp_output_visitor_cleanup(QmpOutputVisitor *v)
+{
+    QStackEntry *e, *tmp;
+
+    /* The bottom QStackEntry, if any, owns the root QObject. See the
+     * qmp_output_push_obj() invocations in qmp_output_add_obj(). */
+    QObject *root = QTAILQ_EMPTY(&v->stack) ? NULL : qmp_output_first(v);
+
+    QTAILQ_FOREACH_SAFE(e, &v->stack, node, tmp) {
+        QTAILQ_REMOVE(&v->stack, e, node);
+        g_free(e);
+    }
+
+    qobject_decref(root);
+    g_free(v);
+}
+
+QmpOutputVisitor *qmp_output_visitor_new(void)
+{
+    QmpOutputVisitor *v;
+
+    v = g_malloc0(sizeof(*v));
+
+    v->visitor.start_struct = qmp_output_start_struct;
+    v->visitor.end_struct = qmp_output_end_struct;
+    v->visitor.start_list = qmp_output_start_list;
+    v->visitor.next_list = qmp_output_next_list;
+    v->visitor.end_list = qmp_output_end_list;
+    v->visitor.type_enum = output_type_enum;
+    v->visitor.type_int = qmp_output_type_int;
+    v->visitor.type_bool = qmp_output_type_bool;
+    v->visitor.type_str = qmp_output_type_str;
+    v->visitor.type_number = qmp_output_type_number;
+
+    QTAILQ_INIT(&v->stack);
+
+    return v;
+}

qemu/qapi/string-input-visitor.c

@@ -0,0 +1,347 @@
+/*
+ * String parsing visitor
+ *
+ * Copyright Red Hat, Inc. 2012
+ *
+ * Author: Paolo Bonzini <pbonzini@redhat.com>
+ *
+ * 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.
+ *
+ */
+
+#include "qemu-common.h"
+#include "qapi/string-input-visitor.h"
+#include "qapi/visitor-impl.h"
+#include "qapi/qmp/qerror.h"
+#include "qemu/option.h"
+#include "qemu/queue.h"
+#include "qemu/range.h"
+
+
+struct StringInputVisitor
+{
+    Visitor visitor;
+
+    bool head;
+
+    GList *ranges;
+    GList *cur_range;
+    int64_t cur;
+
+    const char *string;
+};
+
+static void free_range(void *range, void *dummy)
+{
+    g_free(range);
+}
+
+static void parse_str(StringInputVisitor *siv, Error **errp)
+{
+    char *str = (char *) siv->string;
+    long long start, end;
+    Range *cur;
+    char *endptr;
+
+    if (siv->ranges) {
+        return;
+    }
+
+    do {
+        errno = 0;
+        start = strtoll(str, &endptr, 0);
+        if (errno == 0 && endptr > str) {
+            if (*endptr == '\0') {
+                cur = g_malloc0(sizeof(*cur));
+                cur->begin = start;
+                cur->end = start + 1;
+                siv->ranges = g_list_insert_sorted_merged(siv->ranges, cur,
+                                                          range_compare);
+                cur = NULL;
+                str = NULL;
+            } else if (*endptr == '-') {
+                str = endptr + 1;
+                errno = 0;
+                end = strtoll(str, &endptr, 0);
+                if (errno == 0 && endptr > str && start <= end &&
+                    (start > INT64_MAX - 65536 ||
+                     end < start + 65536)) {
+                    if (*endptr == '\0') {
+                        cur = g_malloc0(sizeof(*cur));
+                        cur->begin = start;
+                        cur->end = end + 1;
+                        siv->ranges =
+                            g_list_insert_sorted_merged(siv->ranges,
+                                                        cur,
+                                                        range_compare);
+                        cur = NULL;
+                        str = NULL;
+                    } else if (*endptr == ',') {
+                        str = endptr + 1;
+                        cur = g_malloc0(sizeof(*cur));
+                        cur->begin = start;
+                        cur->end = end + 1;
+                        siv->ranges =
+                            g_list_insert_sorted_merged(siv->ranges,
+                                                        cur,
+                                                        range_compare);
+                        cur = NULL;
+                    } else {
+                        goto error;
+                    }
+                } else {
+                    goto error;
+                }
+            } else if (*endptr == ',') {
+                str = endptr + 1;
+                cur = g_malloc0(sizeof(*cur));
+                cur->begin = start;
+                cur->end = start + 1;
+                siv->ranges = g_list_insert_sorted_merged(siv->ranges,
+                                                          cur,
+                                                          range_compare);
+                cur = NULL;
+            } else {
+                goto error;
+            }
+        } else {
+            goto error;
+        }
+    } while (str);
+
+    return;
+error:
+    g_list_foreach(siv->ranges, free_range, NULL);
+    g_list_free(siv->ranges);
+    siv->ranges = NULL;
+}
+
+static void
+start_list(Visitor *v, const char *name, Error **errp)
+{
+    StringInputVisitor *siv = DO_UPCAST(StringInputVisitor, visitor, v);
+
+    parse_str(siv, errp);
+
+    siv->cur_range = g_list_first(siv->ranges);
+    if (siv->cur_range) {
+        Range *r = siv->cur_range->data;
+        if (r) {
+            siv->cur = r->begin;
+        }
+    }
+}
+
+static GenericList *
+next_list(Visitor *v, GenericList **list, Error **errp)
+{
+    StringInputVisitor *siv = DO_UPCAST(StringInputVisitor, visitor, v);
+    GenericList **link;
+    Range *r;
+
+    if (!siv->ranges || !siv->cur_range) {
+        return NULL;
+    }
+
+    r = siv->cur_range->data;
+    if (!r) {
+        return NULL;
+    }
+
+    if (siv->cur < r->begin || siv->cur >= r->end) {
+        siv->cur_range = g_list_next(siv->cur_range);
+        if (!siv->cur_range) {
+            return NULL;
+        }
+        r = siv->cur_range->data;
+        if (!r) {
+            return NULL;
+        }
+        siv->cur = r->begin;
+    }
+
+    if (siv->head) {
+        link = list;
+        siv->head = false;
+    } else {
+        link = &(*list)->next;
+    }
+
+    *link = g_malloc0(sizeof **link);
+    return *link;
+}
+
+static void
+end_list(Visitor *v, Error **errp)
+{
+    StringInputVisitor *siv = DO_UPCAST(StringInputVisitor, visitor, v);
+    siv->head = true;
+}
+
+static void parse_type_int(Visitor *v, int64_t *obj, const char *name,
+                           Error **errp)
+{
+    StringInputVisitor *siv = DO_UPCAST(StringInputVisitor, visitor, v);
+
+    if (!siv->string) {
+        error_set(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
+                  "integer");
+        return;
+    }
+
+    parse_str(siv, errp);
+
+    if (!siv->ranges) {
+        goto error;
+    }
+
+    if (!siv->cur_range) {
+        Range *r;
+
+        siv->cur_range = g_list_first(siv->ranges);
+        if (!siv->cur_range) {
+            goto error;
+        }
+
+        r = siv->cur_range->data;
+        if (!r) {
+            goto error;
+        }
+
+        siv->cur = r->begin;
+    }
+
+    *obj = siv->cur;
+    siv->cur++;
+    return;
+
+error:
+    error_set(errp, QERR_INVALID_PARAMETER_VALUE, name,
+              "an int64 value or range");
+}
+
+static void parse_type_size(Visitor *v, uint64_t *obj, const char *name,
+                            Error **errp)
+{
+    StringInputVisitor *siv = DO_UPCAST(StringInputVisitor, visitor, v);
+    Error *err = NULL;
+    uint64_t val;
+
+    if (siv->string) {
+        parse_option_size(name, siv->string, &val, &err);
+    } else {
+        error_set(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
+                  "size");
+        return;
+    }
+    if (err) {
+        error_propagate(errp, err);
+        return;
+    }
+
+    *obj = val;
+}
+
+static void parse_type_bool(Visitor *v, bool *obj, const char *name,
+                            Error **errp)
+{
+    StringInputVisitor *siv = DO_UPCAST(StringInputVisitor, visitor, v);
+
+    if (siv->string) {
+        if (!strcasecmp(siv->string, "on") ||
+            !strcasecmp(siv->string, "yes") ||
+            !strcasecmp(siv->string, "true")) {
+            *obj = true;
+            return;
+        }
+        if (!strcasecmp(siv->string, "off") ||
+            !strcasecmp(siv->string, "no") ||
+            !strcasecmp(siv->string, "false")) {
+            *obj = false;
+            return;
+        }
+    }
+
+    error_set(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
+              "boolean");
+}
+
+static void parse_type_str(Visitor *v, char **obj, const char *name,
+                           Error **errp)
+{
+    StringInputVisitor *siv = DO_UPCAST(StringInputVisitor, visitor, v);
+    if (siv->string) {
+        *obj = g_strdup(siv->string);
+    } else {
+        error_set(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
+                  "string");
+    }
+}
+
+static void parse_type_number(Visitor *v, double *obj, const char *name,
+                              Error **errp)
+{
+    StringInputVisitor *siv = DO_UPCAST(StringInputVisitor, visitor, v);
+    char *endp = (char *) siv->string;
+    double val;
+
+    errno = 0;
+    if (siv->string) {
+        val = strtod(siv->string, &endp);
+    }
+    if (!siv->string || errno || endp == siv->string || *endp) {
+        error_set(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
+                  "number");
+        return;
+    }
+
+    *obj = val;
+}
+
+static void parse_optional(Visitor *v, bool *present, const char *name,
+                           Error **errp)
+{
+    StringInputVisitor *siv = DO_UPCAST(StringInputVisitor, visitor, v);
+
+    if (!siv->string) {
+        *present = false;
+        return;
+    }
+
+    *present = true;
+}
+
+Visitor *string_input_get_visitor(StringInputVisitor *v)
+{
+    return &v->visitor;
+}
+
+void string_input_visitor_cleanup(StringInputVisitor *v)
+{
+    g_list_foreach(v->ranges, free_range, NULL);
+    g_list_free(v->ranges);
+    g_free(v);
+}
+
+StringInputVisitor *string_input_visitor_new(const char *str)
+{
+    StringInputVisitor *v;
+
+    v = g_malloc0(sizeof(*v));
+
+    v->visitor.type_enum = input_type_enum;
+    v->visitor.type_int = parse_type_int;
+    v->visitor.type_size = parse_type_size;
+    v->visitor.type_bool = parse_type_bool;
+    v->visitor.type_str = parse_type_str;
+    v->visitor.type_number = parse_type_number;
+    v->visitor.start_list = start_list;
+    v->visitor.next_list = next_list;
+    v->visitor.end_list = end_list;
+    v->visitor.optional = parse_optional;
+
+    v->string = str;
+    v->head = true;
+    return v;
+}

qemu/qapi/string-output-visitor.c

@@ -0,0 +1,354 @@
+/*
+ * String printing Visitor
+ *
+ * Copyright Red Hat, Inc. 2012
+ *
+ * Author: Paolo Bonzini <pbonzini@redhat.com>
+ *
+ * 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.
+ *
+ */
+
+#include "qemu-common.h"
+#include "qapi/string-output-visitor.h"
+#include "qapi/visitor-impl.h"
+#include "qapi/qmp/qerror.h"
+#include "qemu/host-utils.h"
+#include <math.h>
+#include "qemu/range.h"
+
+enum ListMode {
+    LM_NONE,             /* not traversing a list of repeated options */
+    LM_STARTED,          /* start_list() succeeded */
+
+    LM_IN_PROGRESS,      /* next_list() has been called.
+                          *
+                          * Generating the next list link will consume the most
+                          * recently parsed QemuOpt instance of the repeated
+                          * option.
+                          *
+                          * Parsing a value into the list link will examine the
+                          * next QemuOpt instance of the repeated option, and
+                          * possibly enter LM_SIGNED_INTERVAL or
+                          * LM_UNSIGNED_INTERVAL.
+                          */
+
+    LM_SIGNED_INTERVAL,  /* next_list() has been called.
+                          *
+                          * Generating the next list link will consume the most
+                          * recently stored element from the signed interval,
+                          * parsed from the most recent QemuOpt instance of the
+                          * repeated option. This may consume QemuOpt itself
+                          * and return to LM_IN_PROGRESS.
+                          *
+                          * Parsing a value into the list link will store the
+                          * next element of the signed interval.
+                          */
+
+    LM_UNSIGNED_INTERVAL,/* Same as above, only for an unsigned interval. */
+
+    LM_END
+};
+
+typedef enum ListMode ListMode;
+
+struct StringOutputVisitor
+{
+    Visitor visitor;
+    bool human;
+    GString *string;
+    bool head;
+    ListMode list_mode;
+    union {
+        int64_t s;
+        uint64_t u;
+    } range_start, range_end;
+    GList *ranges;
+};
+
+static void string_output_set(StringOutputVisitor *sov, char *string)
+{
+    if (sov->string) {
+        g_string_free(sov->string, true);
+    }
+    sov->string = g_string_new(string);
+    g_free(string);
+}
+
+static void string_output_append(StringOutputVisitor *sov, int64_t a)
+{
+    Range *r = g_malloc0(sizeof(*r));
+    r->begin = a;
+    r->end = a + 1;
+    sov->ranges = g_list_insert_sorted_merged(sov->ranges, r, range_compare);
+}
+
+static void string_output_append_range(StringOutputVisitor *sov,
+                                       int64_t s, int64_t e)
+{
+    Range *r = g_malloc0(sizeof(*r));
+    r->begin = s;
+    r->end = e + 1;
+    sov->ranges = g_list_insert_sorted_merged(sov->ranges, r, range_compare);
+}
+
+static void format_string(StringOutputVisitor *sov, Range *r, bool next,
+                          bool human)
+{
+    if (r->end - r->begin > 1) {
+        if (human) {
+            g_string_append_printf(sov->string, "0x%" PRIx64 "-0x%" PRIx64,
+                                   r->begin, r->end - 1);
+
+        } else {
+            g_string_append_printf(sov->string, "%" PRId64 "-%" PRId64,
+                                   r->begin, r->end - 1);
+        }
+    } else {
+        if (human) {
+            g_string_append_printf(sov->string, "0x%" PRIx64, r->begin);
+        } else {
+            g_string_append_printf(sov->string, "%" PRId64, r->begin);
+        }
+    }
+    if (next) {
+        g_string_append(sov->string, ",");
+    }
+}
+
+static void print_type_int(Visitor *v, int64_t *obj, const char *name,
+                           Error **errp)
+{
+    StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v);
+    GList *l;
+
+    switch (sov->list_mode) {
+    case LM_NONE:
+        string_output_append(sov, *obj);
+        break;
+
+    case LM_STARTED:
+        sov->range_start.s = *obj;
+        sov->range_end.s = *obj;
+        sov->list_mode = LM_IN_PROGRESS;
+        return;
+
+    case LM_IN_PROGRESS:
+        if (sov->range_end.s + 1 == *obj) {
+            sov->range_end.s++;
+        } else {
+            if (sov->range_start.s == sov->range_end.s) {
+                string_output_append(sov, sov->range_end.s);
+            } else {
+                assert(sov->range_start.s < sov->range_end.s);
+                string_output_append_range(sov, sov->range_start.s,
+                                           sov->range_end.s);
+            }
+
+            sov->range_start.s = *obj;
+            sov->range_end.s = *obj;
+        }
+        return;
+
+    case LM_END:
+        if (sov->range_end.s + 1 == *obj) {
+            sov->range_end.s++;
+            assert(sov->range_start.s < sov->range_end.s);
+            string_output_append_range(sov, sov->range_start.s,
+                                       sov->range_end.s);
+        } else {
+            if (sov->range_start.s == sov->range_end.s) {
+                string_output_append(sov, sov->range_end.s);
+            } else {
+                assert(sov->range_start.s < sov->range_end.s);
+
+                string_output_append_range(sov, sov->range_start.s,
+                                           sov->range_end.s);
+            }
+            string_output_append(sov, *obj);
+        }
+        break;
+
+    default:
+        abort();
+    }
+
+    l = sov->ranges;
+    while (l) {
+        Range *r = l->data;
+        format_string(sov, r, l->next != NULL, false);
+        l = l->next;
+    }
+
+    if (sov->human) {
+        l = sov->ranges;
+        g_string_append(sov->string, " (");
+        while (l) {
+            Range *r = l->data;
+            format_string(sov, r, l->next != NULL, true);
+            l = l->next;
+        }
+        g_string_append(sov->string, ")");
+    }
+}
+
+static void print_type_size(Visitor *v, uint64_t *obj, const char *name,
+                           Error **errp)
+{
+    StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v);
+    static const char suffixes[] = { 'B', 'K', 'M', 'G', 'T', 'P', 'E' };
+    uint64_t div, val;
+    char *out;
+    int i;
+
+    if (!sov->human) {
+        out = g_strdup_printf("%"PRIu64, *obj);
+        string_output_set(sov, out);
+        return;
+    }
+
+    val = *obj;
+
+    /* The exponent (returned in i) minus one gives us
+     * floor(log2(val * 1024 / 1000).  The correction makes us
+     * switch to the higher power when the integer part is >= 1000.
+     */
+    frexp(val / (1000.0 / 1024.0), &i);
+    i = (i - 1) / 10;
+    assert(i < ARRAY_SIZE(suffixes));
+    div = 1ULL << (i * 10);
+
+    out = g_strdup_printf("%"PRIu64" (%0.3g %c%s)", val,
+                          (double)val/div, suffixes[i], i ? "iB" : "");
+    string_output_set(sov, out);
+}
+
+static void print_type_bool(Visitor *v, bool *obj, const char *name,
+                            Error **errp)
+{
+    StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v);
+    string_output_set(sov, g_strdup(*obj ? "true" : "false"));
+}
+
+static void print_type_str(Visitor *v, char **obj, const char *name,
+                           Error **errp)
+{
+    StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v);
+    char *out;
+
+    if (sov->human) {
+        out = *obj ? g_strdup_printf("\"%s\"", *obj) : g_strdup("<null>");
+    } else {
+        out = g_strdup(*obj ? *obj : "");
+    }
+    string_output_set(sov, out);
+}
+
+static void print_type_number(Visitor *v, double *obj, const char *name,
+                              Error **errp)
+{
+    StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v);
+    string_output_set(sov, g_strdup_printf("%f", *obj));
+}
+
+static void
+start_list(Visitor *v, const char *name, Error **errp)
+{
+    StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v);
+
+    /* we can't traverse a list in a list */
+    assert(sov->list_mode == LM_NONE);
+    sov->list_mode = LM_STARTED;
+    sov->head = true;
+}
+
+static GenericList *
+next_list(Visitor *v, GenericList **list, Error **errp)
+{
+    StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v);
+    GenericList *ret = NULL;
+    if (*list) {
+        if (sov->head) {
+            ret = *list;
+        } else {
+            ret = (*list)->next;
+        }
+
+        if (sov->head) {
+            if (ret && ret->next == NULL) {
+                sov->list_mode = LM_NONE;
+            }
+            sov->head = false;
+        } else {
+            if (ret && ret->next == NULL) {
+                sov->list_mode = LM_END;
+            }
+        }
+    }
+
+    return ret;
+}
+
+static void
+end_list(Visitor *v, Error **errp)
+{
+    StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v);
+
+    assert(sov->list_mode == LM_STARTED ||
+           sov->list_mode == LM_END ||
+           sov->list_mode == LM_NONE ||
+           sov->list_mode == LM_IN_PROGRESS);
+    sov->list_mode = LM_NONE;
+    sov->head = true;
+
+}
+
+char *string_output_get_string(StringOutputVisitor *sov)
+{
+    char *string = g_string_free(sov->string, false);
+    sov->string = NULL;
+    return string;
+}
+
+Visitor *string_output_get_visitor(StringOutputVisitor *sov)
+{
+    return &sov->visitor;
+}
+
+static void free_range(void *range, void *dummy)
+{
+    g_free(range);
+}
+
+void string_output_visitor_cleanup(StringOutputVisitor *sov)
+{
+    if (sov->string) {
+        g_string_free(sov->string, true);
+    }
+
+    g_list_foreach(sov->ranges, free_range, NULL);
+    g_list_free(sov->ranges);
+    g_free(sov);
+}
+
+StringOutputVisitor *string_output_visitor_new(bool human)
+{
+    StringOutputVisitor *v;
+
+    v = g_malloc0(sizeof(*v));
+
+    v->string = g_string_new(NULL);
+    v->human = human;
+    v->visitor.type_enum = output_type_enum;
+    v->visitor.type_int = print_type_int;
+    v->visitor.type_size = print_type_size;
+    v->visitor.type_bool = print_type_bool;
+    v->visitor.type_str = print_type_str;
+    v->visitor.type_number = print_type_number;
+    v->visitor.start_list = start_list;
+    v->visitor.next_list = next_list;
+    v->visitor.end_list = end_list;
+
+    return v;
+}