14 files changed, 68 insertions, 50 deletions

diff --git a/include/block/block.h b/include/block/block.h
index 5b81e33e94..a193545b6a 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -63,16 +63,7 @@ typedef enum {
      * content. */
     BDRV_REQ_WRITE_UNCHANGED    = 0x40,
 
-    /*
-     * BDRV_REQ_SERIALISING forces request serialisation for writes.
-     * It is used to ensure that writes to the backing file of a backup process
-     * target cannot race with a read of the backup target that defers to the
-     * backing file.
-     *
-     * Note, that BDRV_REQ_SERIALISING is _not_ opposite in meaning to
-     * BDRV_REQ_NO_SERIALISING. A more descriptive name for the latter might be
-     * _DO_NOT_WAIT_FOR_SERIALISING, except that is too long.
-     */
+    /* Forces request serialisation. Use only with write requests. */
     BDRV_REQ_SERIALISING        = 0x80,
 
     /* Execute the request only if the operation can be offloaded or otherwise
@@ -86,8 +77,15 @@ typedef enum {
      * written to qiov parameter which may be NULL.
      */
     BDRV_REQ_PREFETCH  = 0x200,
+
+    /*
+     * If we need to wait for other requests, just fail immediately. Used
+     * only together with BDRV_REQ_SERIALISING.
+     */
+    BDRV_REQ_NO_WAIT = 0x400,
+
     /* Mask of valid flags */
-    BDRV_REQ_MASK               = 0x3ff,
+    BDRV_REQ_MASK               = 0x7ff,
 } BdrvRequestFlags;
 
 typedef struct BlockSizes {
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 1eeafc118c..b9ef61fe4d 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -1060,7 +1060,8 @@ extern unsigned int bdrv_drain_all_count;
 void bdrv_apply_subtree_drain(BdrvChild *child, BlockDriverState *new_parent);
 void bdrv_unapply_subtree_drain(BdrvChild *child, BlockDriverState *old_parent);
 
-bool coroutine_fn bdrv_mark_request_serialising(BdrvTrackedRequest *req, uint64_t align);
+bool coroutine_fn bdrv_make_request_serialising(BdrvTrackedRequest *req,
+                                                uint64_t align);
 BdrvTrackedRequest *coroutine_fn bdrv_co_get_self_request(BlockDriverState *bs);
 
 int get_tmp_filename(char *filename, int size);
diff --git a/include/migration/vmstate.h b/include/migration/vmstate.h
index 4d71dc8fba..075ee80096 100644
--- a/include/migration/vmstate.h
+++ b/include/migration/vmstate.h
@@ -43,7 +43,7 @@ struct VMStateInfo {
     const char *name;
     int (*get)(QEMUFile *f, void *pv, size_t size, const VMStateField *field);
     int (*put)(QEMUFile *f, void *pv, size_t size, const VMStateField *field,
-               QJSON *vmdesc);
+               JSONWriter *vmdesc);
 };
 
 enum VMStateFlags {
@@ -1169,9 +1169,10 @@ extern const VMStateInfo vmstate_info_qlist;
 int vmstate_load_state(QEMUFile *f, const VMStateDescription *vmsd,
                        void *opaque, int version_id);
 int vmstate_save_state(QEMUFile *f, const VMStateDescription *vmsd,
-                       void *opaque, QJSON *vmdesc);
+                       void *opaque, JSONWriter *vmdesc);
 int vmstate_save_state_v(QEMUFile *f, const VMStateDescription *vmsd,
-                         void *opaque, QJSON *vmdesc, int version_id);
+                         void *opaque, JSONWriter *vmdesc,
+                         int version_id);
 
 bool vmstate_save_needed(const VMStateDescription *vmsd, void *opaque);
 
diff --git a/include/qapi/qmp/json-writer.h b/include/qapi/qmp/json-writer.h
new file mode 100644
index 0000000000..b70ba64077
--- /dev/null
+++ b/include/qapi/qmp/json-writer.h
@@ -0,0 +1,35 @@
+/*
+ * JSON Writer
+ *
+ * Copyright (c) 2020 Red Hat Inc.
+ *
+ * Authors:
+ *  Markus Armbruster <armbru@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.
+ *
+ */
+
+#ifndef JSON_WRITER_H
+#define JSON_WRITER_H
+
+JSONWriter *json_writer_new(bool pretty);
+const char *json_writer_get(JSONWriter *);
+GString *json_writer_get_and_free(JSONWriter *);
+void json_writer_free(JSONWriter *);
+
+G_DEFINE_AUTOPTR_CLEANUP_FUNC(JSONWriter, json_writer_free)
+
+void json_writer_start_object(JSONWriter *, const char *name);
+void json_writer_end_object(JSONWriter *);
+void json_writer_start_array(JSONWriter *, const char *name);
+void json_writer_end_array(JSONWriter *);
+void json_writer_bool(JSONWriter *, const char *name, bool val);
+void json_writer_null(JSONWriter *, const char *name);
+void json_writer_int64(JSONWriter *, const char *name, int64_t val);
+void json_writer_uint64(JSONWriter *, const char *name, uint64_t val);
+void json_writer_double(JSONWriter *, const char *name, double val);
+void json_writer_str(JSONWriter *, const char *name, const char *str);
+
+#endif
diff --git a/include/qapi/qmp/qbool.h b/include/qapi/qmp/qbool.h
index 5f61e38e64..2f888d1057 100644
--- a/include/qapi/qmp/qbool.h
+++ b/include/qapi/qmp/qbool.h
@@ -23,7 +23,5 @@ struct QBool {
 
 QBool *qbool_from_bool(bool value);
 bool qbool_get_bool(const QBool *qb);
-bool qbool_is_equal(const QObject *x, const QObject *y);
-void qbool_destroy_obj(QObject *obj);
 
 #endif /* QBOOL_H */
diff --git a/include/qapi/qmp/qdict.h b/include/qapi/qmp/qdict.h
index da942347a7..9934539c1b 100644
--- a/include/qapi/qmp/qdict.h
+++ b/include/qapi/qmp/qdict.h
@@ -39,10 +39,8 @@ void qdict_put_obj(QDict *qdict, const char *key, QObject *value);
 void qdict_del(QDict *qdict, const char *key);
 int qdict_haskey(const QDict *qdict, const char *key);
 QObject *qdict_get(const QDict *qdict, const char *key);
-bool qdict_is_equal(const QObject *x, const QObject *y);
 const QDictEntry *qdict_first(const QDict *qdict);
 const QDictEntry *qdict_next(const QDict *qdict, const QDictEntry *entry);
-void qdict_destroy_obj(QObject *obj);
 
 /* Helper to qdict_put_obj(), accepts any object */
 #define qdict_put(qdict, key, obj) \
diff --git a/include/qapi/qmp/qjson.h b/include/qapi/qmp/qjson.h
index 5ebbe5a118..593b40b4e0 100644
--- a/include/qapi/qmp/qjson.h
+++ b/include/qapi/qmp/qjson.h
@@ -25,7 +25,7 @@ QDict *qdict_from_vjsonf_nofail(const char *string, va_list ap)
 QDict *qdict_from_jsonf_nofail(const char *string, ...)
     GCC_FMT_ATTR(1, 2);
 
-QString *qobject_to_json(const QObject *obj);
-QString *qobject_to_json_pretty(const QObject *obj);
+GString *qobject_to_json(const QObject *obj);
+GString *qobject_to_json_pretty(const QObject *obj, bool pretty);
 
 #endif /* QJSON_H */
diff --git a/include/qapi/qmp/qlist.h b/include/qapi/qmp/qlist.h
index 595b7943e1..06e98ad5f4 100644
--- a/include/qapi/qmp/qlist.h
+++ b/include/qapi/qmp/qlist.h
@@ -51,8 +51,6 @@ QObject *qlist_pop(QList *qlist);
 QObject *qlist_peek(QList *qlist);
 int qlist_empty(const QList *qlist);
 size_t qlist_size(const QList *qlist);
-bool qlist_is_equal(const QObject *x, const QObject *y);
-void qlist_destroy_obj(QObject *obj);
 
 static inline const QListEntry *qlist_first(const QList *qlist)
 {
diff --git a/include/qapi/qmp/qnull.h b/include/qapi/qmp/qnull.h
index c1426882c5..e84ecceedb 100644
--- a/include/qapi/qmp/qnull.h
+++ b/include/qapi/qmp/qnull.h
@@ -26,6 +26,4 @@ static inline QNull *qnull(void)
     return qobject_ref(&qnull_);
 }
 
-bool qnull_is_equal(const QObject *x, const QObject *y);
-
 #endif /* QNULL_H */
diff --git a/include/qapi/qmp/qnum.h b/include/qapi/qmp/qnum.h
index bbae0a5ec8..7f84e20bfb 100644
--- a/include/qapi/qmp/qnum.h
+++ b/include/qapi/qmp/qnum.h
@@ -68,7 +68,4 @@ double qnum_get_double(QNum *qn);
 
 char *qnum_to_string(QNum *qn);
 
-bool qnum_is_equal(const QObject *x, const QObject *y);
-void qnum_destroy_obj(QObject *obj);
-
 #endif /* QNUM_H */
diff --git a/include/qapi/qmp/qobject.h b/include/qapi/qmp/qobject.h
index fcfd549220..9003b71fd3 100644
--- a/include/qapi/qmp/qobject.h
+++ b/include/qapi/qmp/qobject.h
@@ -64,14 +64,6 @@ QEMU_BUILD_BUG_MSG(QTYPE__MAX != 7,
 #define qobject_to(type, obj)                                       \
     ((type *)qobject_check_type(obj, glue(QTYPE_CAST_TO_, type)))
 
-/* Initialize an object to default values */
-static inline void qobject_init(QObject *obj, QType type)
-{
-    assert(QTYPE_NONE < type && type < QTYPE__MAX);
-    obj->base.refcnt = 1;
-    obj->base.type = type;
-}
-
 static inline void qobject_ref_impl(QObject *obj)
 {
     if (obj) {
@@ -90,6 +82,7 @@ bool qobject_is_equal(const QObject *x, const QObject *y);
 
 /**
  * qobject_destroy(): Free resources used by the object
+ * For use via qobject_unref() only!
  */
 void qobject_destroy(QObject *obj);
 
diff --git a/include/qapi/qmp/qstring.h b/include/qapi/qmp/qstring.h
index e2e356e5e7..1d8ba46936 100644
--- a/include/qapi/qmp/qstring.h
+++ b/include/qapi/qmp/qstring.h
@@ -17,23 +17,13 @@
 
 struct QString {
     struct QObjectBase_ base;
-    char *string;
-    size_t length;
-    size_t capacity;
+    const char *string;
 };
 
 QString *qstring_new(void);
 QString *qstring_from_str(const char *str);
 QString *qstring_from_substr(const char *str, size_t start, size_t end);
-size_t qstring_get_length(const QString *qstring);
+QString *qstring_from_gstring(GString *gstr);
 const char *qstring_get_str(const QString *qstring);
-const char *qstring_get_try_str(const QString *qstring);
-const char *qobject_get_try_str(const QObject *qstring);
-void qstring_append_int(QString *qstring, int64_t value);
-void qstring_append(QString *qstring, const char *str);
-void qstring_append_chr(QString *qstring, int c);
-bool qstring_is_equal(const QObject *x, const QObject *y);
-char *qstring_free(QString *qstring, bool return_str);
-void qstring_destroy_obj(QObject *obj);
 
 #endif /* QSTRING_H */
diff --git a/include/qemu/compiler.h b/include/qemu/compiler.h
index 1b9e58e82b..df9ec08f8a 100644
--- a/include/qemu/compiler.h
+++ b/include/qemu/compiler.h
@@ -222,4 +222,15 @@ extern void QEMU_NORETURN QEMU_ERROR("code path is reachable")
 #define qemu_build_not_reached()  g_assert_not_reached()
 #endif
 
+/**
+ * In most cases, normal "fallthrough" comments are good enough for
+ * switch-case statements, but sometimes the compiler has problems
+ * with those. In that case you can use QEMU_FALLTHROUGH instead.
+ */
+#if __has_attribute(fallthrough)
+# define QEMU_FALLTHROUGH __attribute__((fallthrough))
+#else
+# define QEMU_FALLTHROUGH do {} while (0) /* fallthrough */
+#endif
+
 #endif /* COMPILER_H */
diff --git a/include/qemu/typedefs.h b/include/qemu/typedefs.h
index 6281eae3b5..976b529dfb 100644
--- a/include/qemu/typedefs.h
+++ b/include/qemu/typedefs.h
@@ -57,8 +57,8 @@ typedef struct IOMMUMemoryRegion IOMMUMemoryRegion;
 typedef struct ISABus ISABus;
 typedef struct ISADevice ISADevice;
 typedef struct IsaDma IsaDma;
+typedef struct JSONWriter JSONWriter;
 typedef struct MACAddr MACAddr;
-typedef struct ReservedRegion ReservedRegion;
 typedef struct MachineClass MachineClass;
 typedef struct MachineState MachineState;
 typedef struct MemoryListener MemoryListener;
@@ -107,7 +107,6 @@ typedef struct QEMUSGList QEMUSGList;
 typedef struct QemuSpin QemuSpin;
 typedef struct QEMUTimer QEMUTimer;
 typedef struct QEMUTimerListGroup QEMUTimerListGroup;
-typedef struct QJSON QJSON;
 typedef struct QList QList;
 typedef struct QNull QNull;
 typedef struct QNum QNum;
@@ -115,6 +114,7 @@ typedef struct QObject QObject;
 typedef struct QString QString;
 typedef struct RAMBlock RAMBlock;
 typedef struct Range Range;
+typedef struct ReservedRegion ReservedRegion;
 typedef struct SavedIOTLB SavedIOTLB;
 typedef struct SHPCDevice SHPCDevice;
 typedef struct SSIBus SSIBus;