Merge

26 files changed, 1021 insertions, 537 deletions

diff --git a/tools/libxl/gentest.py b/tools/libxl/gentest.py
index 410b9b76de..04248ee8b1 100644
--- a/tools/libxl/gentest.py
+++ b/tools/libxl/gentest.py
@@ -1,5 +1,6 @@
 #!/usr/bin/python
 
+import os
 import sys
 import re
 import random
@@ -30,7 +31,7 @@ def gen_rand_init(ty, v, indent = "    ", parent = None):
     elif isinstance(ty, idl.KeyedUnion):
         if parent is None:
             raise Exception("KeyedUnion type must have a parent")
-        s += "switch (%s) {\n" % (parent + ty.keyvar_name)
+        s += "switch (%s) {\n" % (parent + ty.keyvar.name)
         for f in ty.fields:
             (nparent,fexpr) = ty.member(v, f, parent is None)
             s += "case %s:\n" % f.enumname
@@ -54,6 +55,8 @@ def gen_rand_init(ty, v, indent = "    ", parent = None):
               ty.pass_arg(v, parent is None))
     elif ty.typename in ["bool"]:
         s += "%s = rand() %% 2;\n" % v
+    elif ty.typename in ["libxl_defbool"]:
+        s += "libxl_defbool_set(%s, !!rand() %% 1);\n" % v
     elif ty.typename in ["char *"]:
         s += "%s = rand_str();\n" % v
     elif ty.private:
@@ -72,7 +75,7 @@ if __name__ == '__main__':
         print >>sys.stderr, "Usage: gentest.py <idl> <implementation>"
         sys.exit(1)
 
-    random.seed()
+    random.seed(os.getenv('LIBXL_TESTIDL_SEED'))
 
     (builtins,types) = idl.parse(sys.argv[1])
 
@@ -196,6 +199,7 @@ static void libxl_string_list_rand_init(libxl_string_list *p)
 }
 """)
     for ty in builtins + types:
+        if isinstance(ty, idl.Number): continue
         if ty.typename not in handcoded:
             f.write("static void %s_rand_init(%s);\n" % \
                     (ty.typename,
diff --git a/tools/libxl/gentypes.py b/tools/libxl/gentypes.py
index ae4a6b6a7a..c1f0cf5116 100644
--- a/tools/libxl/gentypes.py
+++ b/tools/libxl/gentypes.py
@@ -32,6 +32,9 @@ def libxl_C_type_define(ty, indent = ""):
             s += "} %s" % ty.typename
 
     elif isinstance(ty, idl.Aggregate):
+        if isinstance(ty, idl.KeyedUnion):
+            s += libxl_C_instance_of(ty.keyvar.type, ty.keyvar.name) + ";\n"
+            
         if ty.typename is None:
             s += "%s {\n" % ty.kind
         else:
@@ -56,7 +59,7 @@ def libxl_C_type_dispose(ty, v, indent = "    ", parent = None):
     if isinstance(ty, idl.KeyedUnion):
         if parent is None:
             raise Exception("KeyedUnion type must have a parent")
-        s += "switch (%s) {\n" % (parent + ty.keyvar_name)
+        s += "switch (%s) {\n" % (parent + ty.keyvar.name)
         for f in ty.fields:
             (nparent,fexpr) = ty.member(v, f, parent is None)
             s += "case %s:\n" % f.enumname
@@ -75,6 +78,88 @@ def libxl_C_type_dispose(ty, v, indent = "    ", parent = None):
         s = indent + s
     return s.replace("\n", "\n%s" % indent).rstrip(indent)
 
+def libxl_init_members(ty, nesting = 0):
+    """Returns a list of members of ty which require a separate init"""
+
+    if isinstance(ty, idl.Aggregate):
+        return [f for f in ty.fields if not f.const and isinstance(f.type,idl.KeyedUnion)]
+    else:
+        return []
+    
+def _libxl_C_type_init(ty, v, indent = "    ", parent = None, subinit=False):
+    s = ""
+    if isinstance(ty, idl.KeyedUnion):
+        if parent is None:
+            raise Exception("KeyedUnion type must have a parent")
+        if subinit:
+            s += "switch (%s) {\n" % (parent + ty.keyvar.name)
+            for f in ty.fields:
+                (nparent,fexpr) = ty.member(v, f, parent is None)
+                s += "case %s:\n" % f.enumname
+                s += _libxl_C_type_init(f.type, fexpr, "    ", nparent)
+                s += "    break;\n"
+            s += "}\n"
+        else:
+            if ty.keyvar.init_val:
+                s += "%s = %s;\n" % (parent + ty.keyvar.name, ty.keyvar.init_val)
+            elif ty.keyvar.type.init_val:
+                s += "%s = %s;\n" % (parent + ty.keyvar.name, ty.keyvar.type.init_val)
+    elif isinstance(ty, idl.Struct) and (parent is None or ty.init_fn is None):
+        for f in [f for f in ty.fields if not f.const]:
+            (nparent,fexpr) = ty.member(v, f, parent is None)
+            if f.init_val is not None:
+                s += "%s = %s;\n" % (fexpr, f.init_val)
+            else:
+                s += _libxl_C_type_init(f.type, fexpr, "", nparent)
+    else:
+        if ty.init_val is not None:
+            s += "%s = %s;\n" % (ty.pass_arg(v, parent is None), ty.init_val)
+        elif ty.init_fn is not None:
+            s += "%s(%s);\n" % (ty.init_fn, ty.pass_arg(v, parent is None))
+
+    if s != "":
+        s = indent + s
+    return s.replace("\n", "\n%s" % indent).rstrip(indent)
+
+def libxl_C_type_init(ty):
+    s = ""
+    s += "void %s(%s)\n" % (ty.init_fn, ty.make_arg("p", passby=idl.PASS_BY_REFERENCE))
+    s += "{\n"
+    s += "    memset(p, '\\0', sizeof(*p));\n"
+    s += _libxl_C_type_init(ty, "p")
+    s += "}\n"
+    s += "\n"
+    return s
+
+def libxl_C_type_member_init(ty, field):
+    if not isinstance(field.type, idl.KeyedUnion):
+        raise Exception("Only KeyedUnion is supported for member init")
+
+    ku = field.type
+    
+    s = ""
+    s += "void %s(%s, %s)\n" % (ty.init_fn + "_" + ku.keyvar.name,
+                                ty.make_arg("p", passby=idl.PASS_BY_REFERENCE),
+                                ku.keyvar.type.make_arg(ku.keyvar.name))
+    s += "{\n"
+    
+    if ku.keyvar.init_val:
+        init_val = ku.keyvar.init_val
+    elif ku.keyvar.type.init_val:
+        init_val = ku.keyvar.type.init_val
+    else:
+        init_val = None
+        
+    if init_val is not None:
+        (nparent,fexpr) = ty.member(ty.pass_arg("p"), ku.keyvar, isref=True)
+        s += "    assert(%s == %s);\n" % (fexpr, init_val)
+        s += "    %s = %s;\n" % (fexpr, ku.keyvar.name)
+    (nparent,fexpr) = ty.member(ty.pass_arg("p"), field, isref=True)
+    s += _libxl_C_type_init(ku, fexpr, parent=nparent, subinit=True)
+    s += "}\n"
+    s += "\n"
+    return s
+
 def libxl_C_type_gen_json(ty, v, indent = "    ", parent = None):
     s = ""
     if parent is None:
@@ -86,7 +171,7 @@ def libxl_C_type_gen_json(ty, v, indent = "    ", parent = None):
     elif isinstance(ty, idl.KeyedUnion):
         if parent is None:
             raise Exception("KeyedUnion type must have a parent")
-        s += "switch (%s) {\n" % (parent + ty.keyvar_name)
+        s += "switch (%s) {\n" % (parent + ty.keyvar.name)
         for f in ty.fields:
             (nparent,fexpr) = ty.member(v, f, parent is None)
             s += "case %s:\n" % f.enumname
@@ -196,6 +281,15 @@ if __name__ == '__main__':
         f.write(libxl_C_type_define(ty) + ";\n")
         if ty.dispose_fn is not None:
             f.write("void %s(%s);\n" % (ty.dispose_fn, ty.make_arg("p")))
+        if ty.init_fn is not None:
+            f.write("void %s(%s);\n" % (ty.init_fn, ty.make_arg("p")))
+            for field in libxl_init_members(ty):
+                if not isinstance(field.type, idl.KeyedUnion):
+                    raise Exception("Only KeyedUnion is supported for member init")
+                ku = field.type
+                f.write("void %s(%s, %s);\n" % (ty.init_fn + "_" + ku.keyvar.name,
+                                               ty.make_arg("p"),
+                                               ku.keyvar.type.make_arg(ku.keyvar.name)))
         if ty.json_fn is not None:
             f.write("char *%s_to_json(libxl_ctx *ctx, %s);\n" % (ty.typename, ty.make_arg("p")))
         if isinstance(ty, idl.Enumeration):
@@ -224,7 +318,7 @@ if __name__ == '__main__':
 
 """ % (header_json_define, header_json_define, " ".join(sys.argv)))
 
-    for ty in [ty for ty in types+builtins if ty.json_fn is not None]:
+    for ty in [ty for ty in types if ty.json_fn is not None]:
         f.write("yajl_gen_status %s_gen_json(yajl_gen hand, %s);\n" % (ty.typename, ty.make_arg("p", passby=idl.PASS_BY_REFERENCE)))
 
     f.write("\n")
@@ -261,6 +355,11 @@ if __name__ == '__main__':
         f.write("    memset(p, LIBXL_DTOR_POISON, sizeof(*p));\n")
         f.write("}\n")
         f.write("\n")
+        
+    for ty in [t for t in types if t.init_fn is not None and t.autogenerate_init_fn]:
+        f.write(libxl_C_type_init(ty))
+        for field in libxl_init_members(ty):
+            f.write(libxl_C_type_member_init(ty, field))
 
     for ty in [t for t in types if isinstance(t,idl.Enumeration)]:
         f.write("const char *%s_to_string(%s e)\n" % (ty.typename, ty.typename))
diff --git a/tools/libxl/idl.py b/tools/libxl/idl.py
index 880b7ca71d..da8cd88153 100644
--- a/tools/libxl/idl.py
+++ b/tools/libxl/idl.py
@@ -51,6 +51,10 @@ class Type(object):
 
         self.autogenerate_dispose_fn = kwargs.setdefault('autogenerate_dispose_fn', True)
 
+        self.init_fn = kwargs.setdefault('init_fn', None)
+        self.init_val = kwargs.setdefault('init_val', None)
+        self.autogenerate_init_fn = kwargs.setdefault('autogenerate_init_fn', False)
+
         if self.typename is not None and not self.private:
             self.json_fn = kwargs.setdefault('json_fn', self.typename + "_gen_json")
         else:
@@ -144,12 +148,20 @@ class Field(object):
         self.name = name
         self.const = kwargs.setdefault('const', False)
         self.enumname = kwargs.setdefault('enumname', None)
+        self.init_val = kwargs.setdefault('init_val', None)
 
 class Aggregate(Type):
     """A type containing a collection of other types"""
     def __init__(self, kind, typename, fields, **kwargs):
         Type.__init__(self, typename, **kwargs)
 
+        if self.typename is not None:
+            self.init_fn = kwargs.setdefault('init_fn', self.typename + "_init")
+        else:
+            self.init_fn = kwargs.setdefault('init_fn', None)
+
+        self.autogenerate_init_fn = kwargs.setdefault('autogenerate_init_fn', True)
+
         self.kind = kind
 
         self.fields = []
@@ -206,8 +218,9 @@ class KeyedUnion(Aggregate):
         if not isinstance(keyvar_type, Enumeration):
             raise ValueError
 
-        self.keyvar_name = keyvar_name
-        self.keyvar_type = keyvar_type
+        kv_kwargs = dict([(x.lstrip('keyvar_'),y) for (x,y) in kwargs.items() if x.startswith('keyvar_')])
+        
+        self.keyvar = Field(keyvar_type, keyvar_name, **kv_kwargs)
 
         for f in fields:
             # (name, enum, type)
diff --git a/tools/libxl/idl.txt b/tools/libxl/idl.txt
index ddcd0b0050..ecd613a0fe 100644
--- a/tools/libxl/idl.txt
+++ b/tools/libxl/idl.txt
@@ -44,6 +44,22 @@ Type.autogenerate_dispose_fn: (default: True)
  Indicates if the above named Type.dispose_fn should be
  autogenerated.
 
+Type.init_val: (default: None)
+
+ C expression for the value to initialise instances of this type to.
+
+ If present takes precendence over init_fn (see below).
+
+Type.init_fn: (default: typename + "_init" if dir in [IN, BOTH] and
+                        type != None)
+
+ The name of the C function which will initialist Type.
+
+Type.autogenerate_init_fn: (default: True if dir in [IN, BOTH])
+
+ Indicates if the above named Type.init_fn should be
+ autogenerated.
+
 Type.json_fn: (default: typename + "_gen_json" or None if type == None)
 
  The name of the C function which will generate a YAJL data structure
@@ -105,10 +121,13 @@ idl.Aggregate
 
  Each field has the following properties:
 
-  Field.type    The type of the member (a idl.Type).
-  Field.name    The name of the member (can be None for anonymous
-                fields).
-  Field.const   Boolean, true if the member is const.
+  Field.type     The type of the member (a idl.Type).
+  Field.name     The name of the member (can be None for anonymous
+                 fields).
+  Field.const    Boolean, true if the member is const.
+  Field.init_val The initialisation value for this field. Takes
+                 precendence over both Field.type.init_val and
+                 Field.type.init_fn.
 
 idl.Struct
 
@@ -128,10 +147,9 @@ idl.KeyedUnion
  where the currently valid member of the union can be determined based
  upon another member in the containing type.
 
- The KeyedUnion.keyvar_name must contain the name of the member of the
+ The KeyedUnion.keyvar contains an idl.type the member of the
  containing type which determines the valid member of the union. The
- member referenced by KeyedUnion.keyvar_name has type
- KeyedUnion.keyvar_type which must be an instance of the Enumeration type.
+ must be an instance of the Enumeration type.
 
 Standard Types
 --------------
diff --git a/tools/libxl/libxl.c b/tools/libxl/libxl.c
index 327b0402d2..d5e3106d8f 100644
--- a/tools/libxl/libxl.c
+++ b/tools/libxl/libxl.c
@@ -184,6 +184,47 @@ void libxl_key_value_list_dispose(libxl_key_value_list *pkvl)
     free(kvl);
 }
 
+#define LIBXL__DEFBOOL_DEFAULT (0)
+#define LIBXL__DEFBOOL_FALSE (-1)
+#define LIBXL__DEFBOOL_TRUE (1)
+
+void libxl_defbool_set(libxl_defbool *db, bool b)
+{
+    db->val = b ? LIBXL__DEFBOOL_TRUE : LIBXL__DEFBOOL_FALSE;
+}
+
+void libxl_defbool_unset(libxl_defbool *db)
+{
+    db->val = LIBXL__DEFBOOL_DEFAULT;
+}
+
+bool libxl_defbool_is_default(libxl_defbool db)
+{
+    return !db.val;
+}
+
+void libxl_defbool_setdefault(libxl_defbool *db, bool b)
+{
+    if (libxl_defbool_is_default(*db))
+        libxl_defbool_set(db, b);
+}
+
+bool libxl_defbool_val(libxl_defbool db)
+{
+    assert(!libxl_defbool_is_default(db));
+    return db.val > 0;
+}
+
+const char *libxl_defbool_to_string(libxl_defbool b)
+{
+    if (b.val < 0)
+        return "False";
+    else if (b.val > 0)
+        return "True";
+    else
+        return "<default>";
+}
+
 /******************************************************************************/
 
 
@@ -442,6 +483,7 @@ libxl_dominfo * libxl_list_domain(libxl_ctx *ctx, int *nb_domain)
     ret = xc_domain_getinfolist(ctx->xch, 0, 1024, info);
     if (ret<0) {
         LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "geting domain info list");
+        free(ptr);
         return NULL;
     }
 
@@ -464,7 +506,8 @@ int libxl_domain_info(libxl_ctx *ctx, libxl_dominfo *info_r,
     }
     if (ret==0 || xcinfo.domain != domid) return ERROR_INVAL;
 
-    xcinfo2xlinfo(&xcinfo, info_r);
+    if (info_r)
+        xcinfo2xlinfo(&xcinfo, info_r);
     return 0;
 }
 
@@ -491,7 +534,7 @@ libxl_cpupoolinfo * libxl_list_cpupool(libxl_ctx *ctx, int *nb_pool)
         }
         ptr = tmp;
         ptr[i].poolid = info->cpupool_id;
-        ptr[i].sched_id = info->sched_id;
+        ptr[i].sched = info->sched_id;
         ptr[i].n_dom = info->n_dom;
         if (libxl_cpumap_alloc(ctx, &ptr[i].cpumap)) {
             xc_cpupool_infofree(ctx->xch, info);
@@ -986,13 +1029,12 @@ void libxl_evdisable_disk_eject(libxl_ctx *ctx, libxl_evgen_disk_eject *evg) {
 int libxl_domain_destroy(libxl_ctx *ctx, uint32_t domid)
 {
     GC_INIT(ctx);
-    libxl_dominfo dominfo;
     char *dom_path;
     char *vm_path;
     char *pid;
     int rc, dm_present;
 
-    rc = libxl_domain_info(ctx, &dominfo, domid);
+    rc = libxl_domain_info(ctx, NULL, domid);
     switch(rc) {
     case 0:
         break;
@@ -1185,10 +1227,14 @@ int libxl_vncviewer_exec(libxl_ctx *ctx, uint32_t domid, int autopass)
 
 /******************************************************************************/
 
-int libxl_device_disk_init(libxl_ctx *ctx, libxl_device_disk *disk)
+int libxl__device_disk_setdefault(libxl__gc *gc, libxl_device_disk *disk)
 {
-    memset(disk, 0x00, sizeof(libxl_device_disk));
-    return 0;
+    int rc;
+
+    rc = libxl__device_disk_set_backend(gc, disk);
+    if (rc) return rc;
+
+    return rc;
 }
 
 static int libxl__device_from_disk(libxl__gc *gc, uint32_t domid,
@@ -1240,10 +1286,7 @@ int libxl_device_disk_add(libxl_ctx *ctx, uint32_t domid, libxl_device_disk *dis
     libxl__device device;
     int major, minor, rc;
 
-    rc = libxl__device_disk_set_backend(gc, disk);
-    if (rc) goto out;
-
-    rc = libxl__device_disk_set_backend(gc, disk);
+    rc = libxl__device_disk_setdefault(gc, disk);
     if (rc) goto out;
 
     front = flexarray_make(16, 1);
@@ -1395,7 +1438,7 @@ static void libxl__device_disk_from_xs_be(libxl__gc *gc,
     unsigned int len;
     char *tmp;
 
-    libxl_device_disk_init(ctx, disk);
+    libxl_device_disk_init(disk);
 
     tmp = xs_read(ctx->xsh, XBT_NULL,
                   libxl__sprintf(gc, "%s/params", be_path), &len);
@@ -1439,7 +1482,7 @@ int libxl_devid_to_device_disk(libxl_ctx *ctx, uint32_t domid,
     char *dompath, *path;
     int rc = ERROR_FAIL;
 
-    libxl_device_disk_init(ctx, disk);
+    libxl_device_disk_init(disk);
 
     dompath = libxl__xs_get_dompath(gc, domid);
     if (!dompath) {
@@ -1603,7 +1646,7 @@ char * libxl_device_disk_local_attach(libxl_ctx *ctx, libxl_device_disk *disk)
     char *ret = NULL;
     int rc;
 
-    rc = libxl__device_disk_set_backend(gc, disk);
+    rc = libxl__device_disk_setdefault(gc, disk);
     if (rc) goto out;
 
     switch (disk->backend) {
@@ -1670,32 +1713,39 @@ int libxl_device_disk_local_detach(libxl_ctx *ctx, libxl_device_disk *disk)
 }
 
 /******************************************************************************/
-int libxl_device_nic_init(libxl_ctx *ctx, libxl_device_nic *nic)
-{
-    const uint8_t *r;
-    libxl_uuid uuid;
-
-    libxl_uuid_generate(&uuid);
-    r = libxl_uuid_bytearray(&uuid);
-    memset(nic, '\0', sizeof(*nic));
-
-    nic->backend_domid = 0;
-    nic->devid = -1;
-    nic->mtu = 1492;
-    nic->model = strdup("rtl8139");
-    nic->mac[0] = 0x00;
-    nic->mac[1] = 0x16;
-    nic->mac[2] = 0x3e;
-    nic->mac[3] = r[0] & 0x7f;
-    nic->mac[4] = r[1];
-    nic->mac[5] = r[2];
-    nic->ifname = NULL;
-    nic->bridge = strdup("xenbr0");
-    nic->ip = NULL;
-    if ( asprintf(&nic->script, "%s/vif-bridge",
-               libxl_xen_script_dir_path()) < 0 )
+
+int libxl__device_nic_setdefault(libxl__gc *gc, libxl_device_nic *nic)
+{
+    if (!nic->mtu)
+        nic->mtu = 1492;
+    if (!nic->model) {
+        nic->model = strdup("rtl8139");
+        if (!nic->model) return ERROR_NOMEM;
+    }
+    if (!nic->mac[0] && !nic->mac[1] && !nic->mac[2] &&
+        !nic->mac[3] && !nic->mac[4] && !nic->mac[5]) {
+        const uint8_t *r;
+        libxl_uuid uuid;
+
+        libxl_uuid_generate(&uuid);
+        r = libxl_uuid_bytearray(&uuid);
+
+        nic->mac[0] = 0x00;
+        nic->mac[1] = 0x16;
+        nic->mac[2] = 0x3e;
+        nic->mac[3] = r[0] & 0x7f;
+        nic->mac[4] = r[1];
+        nic->mac[5] = r[2];
+    }
+    if (!nic->bridge) {
+        nic->bridge = strdup("xenbr0");
+        if (!nic->bridge) return ERROR_NOMEM;
+    }
+    if ( !nic->script && asprintf(&nic->script, "%s/vif-bridge",
+                                  libxl_xen_script_dir_path()) < 0 )
         return ERROR_FAIL;
-    nic->nictype = LIBXL_NIC_TYPE_IOEMU;
+    if (!nic->nictype)
+        nic->nictype = LIBXL_NIC_TYPE_IOEMU;
     return 0;
 }
 
@@ -1722,6 +1772,9 @@ int libxl_device_nic_add(libxl_ctx *ctx, uint32_t domid, libxl_device_nic *nic)
     char *dompath, **l;
     unsigned int nb, rc;
 
+    rc = libxl__device_nic_setdefault(gc, nic);
+    if (rc) goto out;
+
     front = flexarray_make(16, 1);
     if (!front) {
         rc = ERROR_NOMEM;
@@ -2002,7 +2055,7 @@ int libxl_device_nic_getinfo(libxl_ctx *ctx, uint32_t domid,
 
 /******************************************************************************/
 int libxl__device_console_add(libxl__gc *gc, uint32_t domid,
-                              libxl_device_console *console,
+                              libxl__device_console *console,
                               libxl__domain_build_state *state)
 {
     flexarray_t *front;
@@ -2049,7 +2102,7 @@ int libxl__device_console_add(libxl__gc *gc, uint32_t domid,
     flexarray_append(front, "limit");
     flexarray_append(front, libxl__sprintf(gc, "%d", LIBXL_XENCONSOLE_LIMIT));
     flexarray_append(front, "type");
-    if (console->consback == LIBXL_CONSOLE_BACKEND_XENCONSOLED)
+    if (console->consback == LIBXL__CONSOLE_BACKEND_XENCONSOLED)
         flexarray_append(front, "xenconsoled");
     else
         flexarray_append(front, "ioemu");
@@ -2080,9 +2133,9 @@ out:
 }
 
 /******************************************************************************/
-int libxl_device_vkb_init(libxl_ctx *ctx, libxl_device_vkb *vkb)
+
+int libxl__device_vkb_setdefault(libxl__gc *gc, libxl_device_vkb *vkb)
 {
-    memset(vkb, 0x00, sizeof(libxl_device_vkb));
     return 0;
 }
 
@@ -2108,6 +2161,9 @@ int libxl_device_vkb_add(libxl_ctx *ctx, uint32_t domid, libxl_device_vkb *vkb)
     libxl__device device;
     int rc;
 
+    rc = libxl__device_vkb_setdefault(gc, vkb);
+    if (rc) goto out;
+
     front = flexarray_make(16, 1);
     if (!front) {
         rc = ERROR_NOMEM;
@@ -2185,19 +2241,24 @@ out:
 }
 
 /******************************************************************************/
-int libxl_device_vfb_init(libxl_ctx *ctx, libxl_device_vfb *vfb)
-{
-    memset(vfb, 0x00, sizeof(libxl_device_vfb));
-    vfb->vnc.enable = 1;
-    vfb->vnc.passwd = NULL;
-    vfb->vnc.listen = strdup("127.0.0.1");
-    vfb->vnc.display = 0;
-    vfb->vnc.findunused = 1;
-    vfb->keymap = NULL;
-    vfb->sdl.enable = 0;
-    vfb->sdl.opengl = 0;
-    vfb->sdl.display = NULL;
-    vfb->sdl.xauthority = NULL;
+
+int libxl__device_vfb_setdefault(libxl__gc *gc, libxl_device_vfb *vfb)
+{
+    libxl_defbool_setdefault(&vfb->vnc.enable, true);
+    if (libxl_defbool_val(vfb->vnc.enable)) {
+        if (!vfb->vnc.listen) {
+            vfb->vnc.listen = strdup("127.0.0.1");
+            if (!vfb->vnc.listen) return ERROR_NOMEM;
+        }
+
+        libxl_defbool_setdefault(&vfb->vnc.findunused, true);
+    }
+
+    libxl_defbool_setdefault(&vfb->sdl.enable, false);
+    if (libxl_defbool_val(vfb->sdl.enable)) {
+        libxl_defbool_setdefault(&vfb->sdl.opengl, false);
+    }
+
     return 0;
 }
 
@@ -2222,6 +2283,9 @@ int libxl_device_vfb_add(libxl_ctx *ctx, uint32_t domid, libxl_device_vfb *vfb)
     libxl__device device;
     int rc;
 
+    rc = libxl__device_vfb_setdefault(gc, vfb);
+    if (rc) goto out;
+
     front = flexarray_make(16, 1);
     if (!front) {
         rc = ERROR_NOMEM;
@@ -2241,17 +2305,17 @@ int libxl_device_vfb_add(libxl_ctx *ctx, uint32_t domid, libxl_device_vfb *vfb)
     flexarray_append_pair(back, "state", libxl__sprintf(gc, "%d", 1));
     flexarray_append_pair(back, "domain", libxl__domid_to_name(gc, domid));
     flexarray_append_pair(back, "vnc",
-                          libxl__sprintf(gc, "%d", vfb->vnc.enable));
+                          libxl_defbool_val(vfb->vnc.enable) ? "1" : "0");
     flexarray_append_pair(back, "vnclisten", vfb->vnc.listen);
     flexarray_append_pair(back, "vncpasswd", vfb->vnc.passwd);
     flexarray_append_pair(back, "vncdisplay",
                           libxl__sprintf(gc, "%d", vfb->vnc.display));
     flexarray_append_pair(back, "vncunused",
-                          libxl__sprintf(gc, "%d", vfb->vnc.findunused));
+                          libxl_defbool_val(vfb->vnc.findunused) ? "1" : "0");
     flexarray_append_pair(back, "sdl",
-                          libxl__sprintf(gc, "%d", vfb->sdl.enable));
+                          libxl_defbool_val(vfb->sdl.enable) ? "1" : "0");
     flexarray_append_pair(back, "opengl",
-                          libxl__sprintf(gc, "%d", vfb->sdl.opengl));
+                          libxl_defbool_val(vfb->sdl.opengl) ? "1" : "0");
     if (vfb->sdl.xauthority) {
         flexarray_append_pair(back, "xauthority", vfb->sdl.xauthority);
     }
@@ -2624,18 +2688,23 @@ int libxl_domain_need_memory(libxl_ctx *ctx, libxl_domain_build_info *b_info,
                              uint32_t *need_memkb)
 {
     GC_INIT(ctx);
-    int rc = ERROR_INVAL;
+    int rc;
+
+    rc = libxl__domain_build_info_setdefault(gc, b_info);
+    if (rc) goto out;
+
     *need_memkb = b_info->target_memkb;
     switch (b_info->type) {
     case LIBXL_DOMAIN_TYPE_HVM:
         *need_memkb += b_info->shadow_memkb + LIBXL_HVM_EXTRA_MEMORY;
-        if (b_info->device_model_stubdomain)
+        if (libxl_defbool_val(b_info->device_model_stubdomain))
             *need_memkb += 32 * 1024;
         break;
     case LIBXL_DOMAIN_TYPE_PV:
         *need_memkb += b_info->shadow_memkb + LIBXL_PV_EXTRA_MEMORY;
         break;
     default:
+        rc = ERROR_INVAL;
         goto out;
     }
     if (*need_memkb % (2 * 1024))
@@ -2750,7 +2819,10 @@ int libxl_get_physinfo(libxl_ctx *ctx, libxl_physinfo *physinfo)
     physinfo->sharing_used_frames = xc_sharing_used_frames(ctx->xch);
     physinfo->nr_nodes = xcphysinfo.nr_nodes;
     memcpy(physinfo->hw_cap,xcphysinfo.hw_cap, sizeof(physinfo->hw_cap));
-    physinfo->phys_cap = xcphysinfo.capabilities;
+
+    physinfo->cap_hvm = !!(xcphysinfo.capabilities & XEN_SYSCTL_PHYSCAP_hvm);
+    physinfo->cap_hvm_directio =
+        !!(xcphysinfo.capabilities & XEN_SYSCTL_PHYSCAP_hvm_directio);
 
     return 0;
 }
@@ -2961,14 +3033,11 @@ out:
     return rc;
 }
 
-/*
- * returns one of the XEN_SCHEDULER_* constants from public/domctl.h
- */
-int libxl_get_sched_id(libxl_ctx *ctx)
+libxl_scheduler libxl_get_scheduler(libxl_ctx *ctx)
 {
-    int sched, ret;
+    libxl_scheduler sched, ret;
 
-    if ((ret = xc_sched_id(ctx->xch, &sched)) != 0) {
+    if ((ret = xc_sched_id(ctx->xch, (int *)&sched)) != 0) {
         LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "getting domain info list");
         return ERROR_FAIL;
     }
@@ -2981,6 +3050,8 @@ int libxl_sched_credit_domain_get(libxl_ctx *ctx, uint32_t domid,
     struct xen_domctl_sched_credit sdom;
     int rc;
 
+    libxl_sched_credit_domain_init(scinfo);
+
     rc = xc_sched_credit_domain_get(ctx->xch, domid, &sdom);
     if (rc != 0) {
         LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "getting domain sched credit");
@@ -3040,6 +3111,8 @@ int libxl_sched_credit2_domain_get(libxl_ctx *ctx, uint32_t domid,
     struct xen_domctl_sched_credit2 sdom;
     int rc;
 
+    libxl_sched_credit2_domain_init(scinfo);
+
     rc = xc_sched_credit2_domain_get(ctx->xch, domid, &sdom);
     if (rc != 0) {
         LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR,
@@ -3097,6 +3170,8 @@ int libxl_sched_sedf_domain_get(libxl_ctx *ctx, uint32_t domid,
     uint16_t weight;
     int rc;
 
+    libxl_sched_sedf_domain_init(scinfo);
+
     rc = xc_sedf_domain_get(ctx->xch, domid, &period, &slice, &latency,
                             &extratime, &weight);
     if (rc != 0) {
@@ -3443,7 +3518,8 @@ int libxl_get_freecpus(libxl_ctx *ctx, libxl_cpumap *cpumap)
     return 0;
 }
 
-int libxl_cpupool_create(libxl_ctx *ctx, const char *name, int schedid,
+int libxl_cpupool_create(libxl_ctx *ctx, const char *name,
+                         libxl_scheduler sched,
                          libxl_cpumap cpumap, libxl_uuid *uuid,
                          uint32_t *poolid)
 {
@@ -3459,7 +3535,7 @@ int libxl_cpupool_create(libxl_ctx *ctx, const char *name, int schedid,
         return ERROR_NOMEM;
     }
 
-    rc = xc_cpupool_create(ctx->xch, poolid, schedid);
+    rc = xc_cpupool_create(ctx->xch, poolid, sched);
     if (rc) {
         LIBXL__LOG_ERRNOVAL(ctx, LIBXL__LOG_ERROR, rc,
            "Could not create cpupool");
diff --git a/tools/libxl/libxl.h b/tools/libxl/libxl.h
index 5d904eecae..1f619c0593 100644
--- a/tools/libxl/libxl.h
+++ b/tools/libxl/libxl.h
@@ -124,6 +124,50 @@
  * Therefore public functions which initialize a libxl__gc MUST call
  * libxl__free_all() before returning.
  */
+/*
+ * libxl types
+ *
+ * Most libxl types are defined by the libxl IDL (see
+ * libxl_types.idl). The library provides a common set of methods for
+ * initialising and freeing these types.
+ *
+ * void libxl_<type>_init(<type> *p):
+ *
+ *    Initialises the members of "p" to all defaults. These may either
+ *    be special value which indicates to the library that it should
+ *    select an appropriate default when using this field or actual
+ *    default values.
+ *
+ *    Some fields within a data type (e.g. unions) cannot be sensibly
+ *    initialised without further information. In these cases a
+ *    separate subfield initialisation function is provided (see
+ *    below).
+ *
+ *    An instance which has been initialised using this method can
+ *    always be safely passed to the dispose function (see
+ *    below). This is true even if the data type contains fields which
+ *    require a separate call to a subfield initialisation function.
+ *
+ *    This method is provided for any aggregate type which is used as
+ *    an input parameter.
+ *
+ * void libxl_<type>_init_<subfield>(<type> *p, subfield):
+ *
+ *    Initialise those parts of "p" which are not initialised by the
+ *    main init function due to the unknown value of "subfield". Sets
+ *    p->subfield as well as initialising any fields to their default
+ *    values.
+ *
+ *    p->subfield must not have been previously initialised.
+ *
+ *    This method is provided for any aggregate type.
+ *
+ * void libxl_<type>_dispose(instance *p):
+ *
+ *    Frees any dynamically allocated memory used by the members of
+ *    "p" but not the storage used by "p" itself (this allows for the
+ *    allocation of arrays of types and for the composition of types).
+ */
 #ifndef LIBXL_H
 #define LIBXL_H
 
@@ -137,9 +181,6 @@
 
 #include <xentoollog.h>
 
-#include <xen/sched.h>
-#include <xen/sysctl.h>
-
 #include <libxl_uuid.h>
 #include <_libxl_list.h>
 
@@ -202,9 +243,34 @@ typedef struct {
 struct libxl_event;
 typedef LIBXL_TAILQ_ENTRY(struct libxl_event) libxl_ev_link;
 
+/*
+ * A boolean variable with an explicit default state.
+ *
+ * Users should treat this struct as opaque and use the following
+ * defined macros and accessor functions.
+ *
+ * To allow users of the library to naively select all defaults this
+ * state is represented as 0. False is < 0 and True is > 0.
+ */
+typedef struct {
+    int val;
+} libxl_defbool;
+
+void libxl_defbool_set(libxl_defbool *db, bool b);
+/* Resets to default */
+void libxl_defbool_unset(libxl_defbool *db);
+/* Sets db only if it is currently == default */
+void libxl_defbool_setdefault(libxl_defbool *db, bool b);
+bool libxl_defbool_is_default(libxl_defbool db);
+/* db must not be == default */
+bool libxl_defbool_val(libxl_defbool db);
+
+const char *libxl_defbool_to_string(libxl_defbool b);
+
 typedef struct libxl__ctx libxl_ctx;
 
-#define LIBXL_TIMER_MODE_DEFAULT LIBXL_TIMER_MODE_NO_DELAY_FOR_MISSED_TICKS
+#define LIBXL_TIMER_MODE_DEFAULT -1
+#define LIBXL_MEMKB_DEFAULT ~0ULL
 
 #include "_libxl_types.h"
 
@@ -315,10 +381,6 @@ int libxl_ctx_free(libxl_ctx *ctx /* 0 is OK */);
 int libxl_ctx_postfork(libxl_ctx *ctx);
 
 /* domain related functions */
-int libxl_init_create_info(libxl_ctx *ctx, libxl_domain_create_info *c_info);
-int libxl_init_build_info(libxl_ctx *ctx,
-                          libxl_domain_build_info *b_info,
-                          libxl_domain_create_info *c_info);
 typedef int (*libxl_console_ready)(libxl_ctx *ctx, uint32_t domid, void *priv);
 int libxl_domain_create_new(libxl_ctx *ctx, libxl_domain_config *d_config, libxl_console_ready cb, void *priv, uint32_t *domid);
 int libxl_domain_create_restore(libxl_ctx *ctx, libxl_domain_config *d_config, libxl_console_ready cb, void *priv, uint32_t *domid, int restore_fd);
@@ -390,11 +452,14 @@ int libxl_console_exec(libxl_ctx *ctx, uint32_t domid, int cons_num, libxl_conso
  * guests using pygrub. */
 int libxl_primary_console_exec(libxl_ctx *ctx, uint32_t domid_vm);
 
+/* May be called with info_r == NULL to check for domain's existance */
 int libxl_domain_info(libxl_ctx*, libxl_dominfo *info_r,
                       uint32_t domid);
 libxl_dominfo * libxl_list_domain(libxl_ctx*, int *nb_domain);
+void libxl_dominfo_list_free(libxl_dominfo *list, int nr);
 libxl_cpupoolinfo * libxl_list_cpupool(libxl_ctx*, int *nb_pool);
 libxl_vminfo * libxl_list_vm(libxl_ctx *ctx, int *nb_vm);
+void libxl_vminfo_list_free(libxl_vminfo *list, int nr);
 
 /*
  * Devices
@@ -405,8 +470,9 @@ libxl_vminfo * libxl_list_vm(libxl_ctx *ctx, int *nb_vm);
  * additional data type libxl_device_<TYPE>_getinfo which contains
  * further runtime information about the device.
  *
- * A common set of methods are available for each device type. These
- * are described below.
+ * In addition to the general methods available for libxl types (see
+ * "libxl types" above) a common set of methods are available for each
+ * device type. These are described below.
  *
  * Querying
  * --------
@@ -424,10 +490,6 @@ libxl_vminfo * libxl_list_vm(libxl_ctx *ctx, int *nb_vm);
  * Creation / Control
  * ------------------
  *
- * libxl_device_<type>_init(ctx, device):
- *
- *    Initalises device to a default configuration.
- *
  * libxl_device_<type>_add(ctx, domid, device):
  *
  *   Adds the given device to the specified domain. This can be called
@@ -457,7 +519,6 @@ libxl_vminfo * libxl_list_vm(libxl_ctx *ctx, int *nb_vm);
  */
 
 /* Disks */
-int libxl_device_disk_init(libxl_ctx *ctx, libxl_device_disk *disk);
 int libxl_device_disk_add(libxl_ctx *ctx, uint32_t domid, libxl_device_disk *disk);
 int libxl_device_disk_remove(libxl_ctx *ctx, uint32_t domid,
                              libxl_device_disk *disk,
@@ -483,7 +544,6 @@ char * libxl_device_disk_local_attach(libxl_ctx *ctx, libxl_device_disk *disk);
 int libxl_device_disk_local_detach(libxl_ctx *ctx, libxl_device_disk *disk);
 
 /* Network Interfaces */
-int libxl_device_nic_init(libxl_ctx *ctx, libxl_device_nic *nic);
 int libxl_device_nic_add(libxl_ctx *ctx, uint32_t domid, libxl_device_nic *nic);
 int libxl_device_nic_remove(libxl_ctx *ctx, uint32_t domid,
                             libxl_device_nic *nic,
@@ -495,7 +555,6 @@ int libxl_device_nic_getinfo(libxl_ctx *ctx, uint32_t domid,
                               libxl_device_nic *nic, libxl_nicinfo *nicinfo);
 
 /* Keyboard */
-int libxl_device_vkb_init(libxl_ctx *ctx, libxl_device_vkb *vkb);
 int libxl_device_vkb_add(libxl_ctx *ctx, uint32_t domid, libxl_device_vkb *vkb);
 int libxl_device_vkb_remove(libxl_ctx *ctx, uint32_t domid,
                             libxl_device_vkb *vkb,
@@ -503,7 +562,6 @@ int libxl_device_vkb_remove(libxl_ctx *ctx, uint32_t domid,
 int libxl_device_vkb_destroy(libxl_ctx *ctx, uint32_t domid, libxl_device_vkb *vkb);
 
 /* Framebuffer */
-int libxl_device_vfb_init(libxl_ctx *ctx, libxl_device_vfb *vfb);
 int libxl_device_vfb_add(libxl_ctx *ctx, uint32_t domid, libxl_device_vfb *vfb);
 int libxl_device_vfb_remove(libxl_ctx *ctx, uint32_t domid,
                             libxl_device_vfb *vfb,
@@ -511,7 +569,6 @@ int libxl_device_vfb_remove(libxl_ctx *ctx, uint32_t domid,
 int libxl_device_vfb_destroy(libxl_ctx *ctx, uint32_t domid, libxl_device_vfb *vfb);
 
 /* PCI Passthrough */
-int libxl_device_pci_init(libxl_ctx *ctx, libxl_device_pci *pci);
 int libxl_device_pci_add(libxl_ctx *ctx, uint32_t domid, libxl_device_pci *pcidev);
 int libxl_device_pci_remove(libxl_ctx *ctx, uint32_t domid, libxl_device_pci *pcidev);
 int libxl_device_pci_destroy(libxl_ctx *ctx, uint32_t domid, libxl_device_pci *pcidev);
@@ -584,7 +641,7 @@ int libxl_set_vcpuaffinity_all(libxl_ctx *ctx, uint32_t domid,
                                unsigned int max_vcpus, libxl_cpumap *cpumap);
 int libxl_set_vcpuonline(libxl_ctx *ctx, uint32_t domid, libxl_cpumap *cpumap);
 
-int libxl_get_sched_id(libxl_ctx *ctx);
+libxl_scheduler libxl_get_scheduler(libxl_ctx *ctx);
 
 
 int libxl_sched_credit_domain_get(libxl_ctx *ctx, uint32_t domid,
@@ -627,7 +684,8 @@ int libxl_tmem_shared_auth(libxl_ctx *ctx, uint32_t domid, char* uuid,
 int libxl_tmem_freeable(libxl_ctx *ctx);
 
 int libxl_get_freecpus(libxl_ctx *ctx, libxl_cpumap *cpumap);
-int libxl_cpupool_create(libxl_ctx *ctx, const char *name, int schedid,
+int libxl_cpupool_create(libxl_ctx *ctx, const char *name,
+                         libxl_scheduler sched,
                          libxl_cpumap cpumap, libxl_uuid *uuid,
                          uint32_t *poolid);
 int libxl_cpupool_destroy(libxl_ctx *ctx, uint32_t poolid);
@@ -638,12 +696,7 @@ int libxl_cpupool_cpuremove(libxl_ctx *ctx, uint32_t poolid, int cpu);
 int libxl_cpupool_cpuremove_node(libxl_ctx *ctx, uint32_t poolid, int node, int *cpus);
 int libxl_cpupool_movedomain(libxl_ctx *ctx, uint32_t poolid, uint32_t domid);
 
-static inline int libxl_domid_valid_guest(uint32_t domid)
-{
-    /* returns 1 if the value _could_ be a valid guest domid, 0 otherwise
-     * does not check whether the domain actually exists */
-    return domid > 0 && domid < DOMID_FIRST_RESERVED;
-}
+int libxl_domid_valid_guest(uint32_t domid);
 
 int libxl_flask_context_to_sid(libxl_ctx *ctx, char *buf, size_t len,
                                uint32_t *ssidref);
diff --git a/tools/libxl/libxl_bootloader.c b/tools/libxl/libxl_bootloader.c
index 907c871f65..277406227d 100644
--- a/tools/libxl/libxl_bootloader.c
+++ b/tools/libxl/libxl_bootloader.c
@@ -346,9 +346,15 @@ int libxl_run_bootloader(libxl_ctx *ctx,
 
     struct stat st_buf;
 
+    rc = libxl__domain_build_info_setdefault(gc, info);
+    if (rc) goto out;
+
     if (info->type != LIBXL_DOMAIN_TYPE_PV || !info->u.pv.bootloader)
         goto out;
 
+    rc = libxl__domain_build_info_setdefault(gc, info);
+    if (rc) goto out;
+
     rc = ERROR_INVAL;
     if (!disk)
         goto out;
diff --git a/tools/libxl/libxl_create.c b/tools/libxl/libxl_create.c
index 85a4a9ed70..97807595b7 100644
--- a/tools/libxl/libxl_create.c
+++ b/tools/libxl/libxl_create.c
@@ -50,79 +50,141 @@ void libxl_domain_config_dispose(libxl_domain_config *d_config)
     libxl_domain_build_info_dispose(&d_config->b_info);
 }
 
-int libxl_init_create_info(libxl_ctx *ctx, libxl_domain_create_info *c_info)
+int libxl__domain_create_info_setdefault(libxl__gc *gc,
+                                         libxl_domain_create_info *c_info)
 {
-    memset(c_info, '\0', sizeof(*c_info));
-    c_info->xsdata = NULL;
-    c_info->platformdata = NULL;
-    c_info->hap = 1;
-    c_info->type = LIBXL_DOMAIN_TYPE_HVM;
-    c_info->oos = 1;
-    c_info->ssidref = 0;
-    c_info->poolid = 0;
+    if (!c_info->type)
+        return ERROR_INVAL;
+
+    if (c_info->type == LIBXL_DOMAIN_TYPE_HVM) {
+        libxl_defbool_setdefault(&c_info->hap, true);
+        libxl_defbool_setdefault(&c_info->oos, true);
+    }
+
     return 0;
 }
 
-int libxl_init_build_info(libxl_ctx *ctx,
-                          libxl_domain_build_info *b_info,
-                          libxl_domain_create_info *c_info)
+int libxl__domain_build_info_setdefault(libxl__gc *gc,
+                                        libxl_domain_build_info *b_info)
 {
-    memset(b_info, '\0', sizeof(*b_info));
-    b_info->max_vcpus = 1;
-    b_info->cur_vcpus = 1;
-    if (libxl_cpumap_alloc(ctx, &b_info->cpumap))
-        return ERROR_NOMEM;
-    libxl_cpumap_set_any(&b_info->cpumap);
-    b_info->max_memkb = 32 * 1024;
-    b_info->target_memkb = b_info->max_memkb;
-    b_info->disable_migrate = 0;
-    b_info->cpuid = NULL;
-    b_info->shadow_memkb = 0;
-    b_info->type = c_info->type;
-
-    b_info->device_model_version =
-        LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN_TRADITIONAL;
-    b_info->device_model_stubdomain = false;
-    b_info->device_model = NULL;
+    if (!b_info->device_model_version)
+        b_info->device_model_version =
+            LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN_TRADITIONAL;
+
+    if (!b_info->u.hvm.bios)
+        switch (b_info->device_model_version) {
+        case 1: b_info->u.hvm.bios = LIBXL_BIOS_TYPE_ROMBIOS; break;
+        case 2: b_info->u.hvm.bios = LIBXL_BIOS_TYPE_SEABIOS; break;
+        default:return ERROR_INVAL;
+    }
+
+    /* Enforce BIOS<->Device Model version relationship */
+    switch (b_info->device_model_version) {
+    case 1:
+        if (b_info->u.hvm.bios != LIBXL_BIOS_TYPE_ROMBIOS)
+            return ERROR_INVAL;
+        break;
+    case 2:
+        if (b_info->u.hvm.bios == LIBXL_BIOS_TYPE_ROMBIOS)
+            return ERROR_INVAL;
+        break;
+    default:abort();
+    }
+
+    libxl_defbool_setdefault(&b_info->device_model_stubdomain, false);
+
+    if (b_info->type == LIBXL_DOMAIN_TYPE_HVM &&
+        b_info->device_model_version !=
+            LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN_TRADITIONAL &&
+        libxl_defbool_val(b_info->device_model_stubdomain)) {
+        LIBXL__LOG(CTX, XTL_ERROR,
+            "device model stubdomains require \"qemu-xen-traditional\"");
+        return ERROR_INVAL;
+    }
+
+    if (!b_info->max_vcpus)
+        b_info->max_vcpus = 1;
+    if (!b_info->cur_vcpus)
+        b_info->cur_vcpus = 1;
+
+    if (!b_info->cpumap.size) {
+        if (libxl_cpumap_alloc(CTX, &b_info->cpumap))
+            return ERROR_NOMEM;
+        libxl_cpumap_set_any(&b_info->cpumap);
+    }
+
+    if (b_info->max_memkb == LIBXL_MEMKB_DEFAULT)
+        b_info->max_memkb = 32 * 1024;
+    if (b_info->target_memkb == LIBXL_MEMKB_DEFAULT)
+        b_info->target_memkb = b_info->max_memkb;
+
+    libxl_defbool_setdefault(&b_info->disable_migrate, false);
 
     switch (b_info->type) {
     case LIBXL_DOMAIN_TYPE_HVM:
-        b_info->video_memkb = 8 * 1024;
-        b_info->u.hvm.firmware = NULL;
-        b_info->u.hvm.bios = 0;
-        b_info->u.hvm.pae = 1;
-        b_info->u.hvm.apic = 1;
-        b_info->u.hvm.acpi = 1;
-        b_info->u.hvm.acpi_s3 = 1;
-        b_info->u.hvm.acpi_s4 = 1;
-        b_info->u.hvm.nx = 1;
-        b_info->u.hvm.viridian = 0;
-        b_info->u.hvm.hpet = 1;
-        b_info->u.hvm.vpt_align = 1;
-        b_info->u.hvm.timer_mode = 1;
-        b_info->u.hvm.nested_hvm = 0;
-        b_info->u.hvm.no_incr_generationid = 0;
-
-        b_info->u.hvm.stdvga = 0;
-        b_info->u.hvm.vnc.enable = 1;
-        b_info->u.hvm.vnc.listen = strdup("127.0.0.1");
-        b_info->u.hvm.vnc.display = 0;
-        b_info->u.hvm.vnc.findunused = 1;
-        b_info->u.hvm.keymap = NULL;
-        b_info->u.hvm.sdl.enable = 0;
-        b_info->u.hvm.sdl.opengl = 0;
-        b_info->u.hvm.nographic = 0;
-        b_info->u.hvm.serial = NULL;
-        b_info->u.hvm.boot = strdup("cda");
-        b_info->u.hvm.usb = 0;
-        b_info->u.hvm.usbdevice = NULL;
-        b_info->u.hvm.xen_platform_pci = 1;
+        if (b_info->shadow_memkb == LIBXL_MEMKB_DEFAULT)
+            b_info->shadow_memkb = 0;
+        if (b_info->video_memkb == LIBXL_MEMKB_DEFAULT)
+            b_info->video_memkb = 8 * 1024;
+        if (b_info->u.hvm.timer_mode == LIBXL_TIMER_MODE_DEFAULT)
+            b_info->u.hvm.timer_mode =
+                LIBXL_TIMER_MODE_NO_DELAY_FOR_MISSED_TICKS;
+
+        libxl_defbool_setdefault(&b_info->u.hvm.pae,                true);
+        libxl_defbool_setdefault(&b_info->u.hvm.apic,               true);
+        libxl_defbool_setdefault(&b_info->u.hvm.acpi,               true);
+        libxl_defbool_setdefault(&b_info->u.hvm.acpi_s3,            true);
+        libxl_defbool_setdefault(&b_info->u.hvm.acpi_s4,            true);
+        libxl_defbool_setdefault(&b_info->u.hvm.nx,                 true);
+        libxl_defbool_setdefault(&b_info->u.hvm.viridian,           false);
+        libxl_defbool_setdefault(&b_info->u.hvm.hpet,               true);
+        libxl_defbool_setdefault(&b_info->u.hvm.vpt_align,          true);
+        libxl_defbool_setdefault(&b_info->u.hvm.nested_hvm,         false);
+        libxl_defbool_setdefault(&b_info->u.hvm.incr_generationid,  false);
+        libxl_defbool_setdefault(&b_info->u.hvm.usb,                false);
+        libxl_defbool_setdefault(&b_info->u.hvm.xen_platform_pci,   true);
+
+        if (!b_info->u.hvm.boot) {
+            b_info->u.hvm.boot = strdup("cda");
+            if (!b_info->u.hvm.boot) return ERROR_NOMEM;
+        }
+
+        libxl_defbool_setdefault(&b_info->u.hvm.stdvga, false);
+        libxl_defbool_setdefault(&b_info->u.hvm.vnc.enable, true);
+        if (libxl_defbool_val(b_info->u.hvm.vnc.enable)) {
+            libxl_defbool_setdefault(&b_info->u.hvm.vnc.findunused, true);
+            if (!b_info->u.hvm.vnc.listen) {
+                b_info->u.hvm.vnc.listen = strdup("127.0.0.1");
+                if (!b_info->u.hvm.vnc.listen) return ERROR_NOMEM;
+            }
+        }
+
+        libxl_defbool_setdefault(&b_info->u.hvm.sdl.enable, false);
+        if (libxl_defbool_val(b_info->u.hvm.sdl.enable)) {
+            libxl_defbool_setdefault(&b_info->u.hvm.sdl.opengl, false);
+        }
+
+        libxl_defbool_setdefault(&b_info->u.hvm.spice.enable, false);
+        if (libxl_defbool_val(b_info->u.hvm.spice.enable)) {
+            libxl_defbool_setdefault(&b_info->u.hvm.spice.disable_ticketing,
+                                     false);
+            libxl_defbool_setdefault(&b_info->u.hvm.spice.agent_mouse, true);
+        }
+
+        libxl_defbool_setdefault(&b_info->u.hvm.nographic, false);
+
+        libxl_defbool_setdefault(&b_info->u.hvm.gfx_passthru, false);
+
         break;
     case LIBXL_DOMAIN_TYPE_PV:
-        b_info->u.pv.slack_memkb = 8 * 1024;
+        libxl_defbool_setdefault(&b_info->u.pv.e820_host, false);
+        if (b_info->shadow_memkb == LIBXL_MEMKB_DEFAULT)
+            b_info->shadow_memkb = 0;
+        if (b_info->u.pv.slack_memkb == LIBXL_MEMKB_DEFAULT)
+            b_info->u.pv.slack_memkb = 0;
         break;
     default:
-        LIBXL__LOG(ctx, LIBXL__LOG_ERROR,
+        LIBXL__LOG(CTX, LIBXL__LOG_ERROR,
                    "invalid domain type %s in create info",
                    libxl_domain_type_to_string(b_info->type));
         return ERROR_INVAL;
@@ -130,17 +192,16 @@ int libxl_init_build_info(libxl_ctx *ctx,
     return 0;
 }
 
-static int init_console_info(libxl_device_console *console, int dev_num)
+static int init_console_info(libxl__device_console *console, int dev_num)
 {
-    memset(console, 0x00, sizeof(libxl_device_console));
+    memset(console, 0x00, sizeof(libxl__device_console));
     console->devid = dev_num;
-    console->consback = LIBXL_CONSOLE_BACKEND_XENCONSOLED;
+    console->consback = LIBXL__CONSOLE_BACKEND_XENCONSOLED;
     console->output = strdup("pty");
-    if ( NULL == console->output )
+    if (!console->output)
         return ERROR_NOMEM;
     return 0;
 }
-
 int libxl__domain_build(libxl__gc *gc,
                         libxl_domain_build_info *info,
                         uint32_t domid,
@@ -172,11 +233,11 @@ int libxl__domain_build(libxl__gc *gc,
 
         localents = libxl__calloc(gc, 7, sizeof(char *));
         localents[0] = "platform/acpi";
-        localents[1] = (info->u.hvm.acpi) ? "1" : "0";
+        localents[1] = libxl_defbool_val(info->u.hvm.acpi) ? "1" : "0";
         localents[2] = "platform/acpi_s3";
-        localents[3] = (info->u.hvm.acpi_s3) ? "1" : "0";
+        localents[3] = libxl_defbool_val(info->u.hvm.acpi_s3) ? "1" : "0";
         localents[4] = "platform/acpi_s4";
-        localents[5] = (info->u.hvm.acpi_s4) ? "1" : "0";
+        localents[5] = libxl_defbool_val(info->u.hvm.acpi_s4) ? "1" : "0";
 
         break;
     case LIBXL_DOMAIN_TYPE_PV:
@@ -320,8 +381,8 @@ int libxl__domain_make(libxl__gc *gc, libxl_domain_create_info *info,
     flags = 0;
     if (info->type == LIBXL_DOMAIN_TYPE_HVM) {
         flags |= XEN_DOMCTL_CDF_hvm_guest;
-        flags |= info->hap ? XEN_DOMCTL_CDF_hap : 0;
-        flags |= info->oos ? 0 : XEN_DOMCTL_CDF_oos_off;
+        flags |= libxl_defbool_val(info->hap) ? XEN_DOMCTL_CDF_hap : 0;
+        flags |= libxl_defbool_val(info->oos) ? 0 : XEN_DOMCTL_CDF_oos_off;
     }
     *domid = -1;
 
@@ -378,7 +439,6 @@ retry_transaction:
     xs_rm(ctx->xsh, t, dom_path);
     libxl__xs_mkdir(gc, t, dom_path, roperm, ARRAY_SIZE(roperm));
 
-
     xs_rm(ctx->xsh, t, vm_path);
     libxl__xs_mkdir(gc, t, vm_path, roperm, ARRAY_SIZE(roperm));
 
@@ -470,6 +530,12 @@ static int do_domain_create(libxl__gc *gc, libxl_domain_config *d_config,
 
     domid = 0;
 
+    ret = libxl__domain_create_info_setdefault(gc, &d_config->c_info);
+    if (ret) goto error_out;
+
+    ret = libxl__domain_create_info_setdefault(gc, &d_config->c_info);
+    if (ret) goto error_out;
+
     ret = libxl__domain_make(gc, &d_config->c_info, &domid);
     if (ret) {
         LIBXL__LOG(ctx, LIBXL__LOG_ERROR, "cannot make domain: %d", ret);
@@ -482,9 +548,11 @@ static int do_domain_create(libxl__gc *gc, libxl_domain_config *d_config,
             goto error_out;
     }
 
+    ret = libxl__domain_build_info_setdefault(gc, &d_config->b_info);
+    if (ret) goto error_out;
 
     for (i = 0; i < d_config->num_disks; i++) {
-        ret = libxl__device_disk_set_backend(gc, &d_config->disks[i]);
+        ret = libxl__device_disk_setdefault(gc, &d_config->disks[i]);
         if (ret) goto error_out;
     }
 
@@ -534,18 +602,16 @@ static int do_domain_create(libxl__gc *gc, libxl_domain_config *d_config,
     switch (d_config->c_info.type) {
     case LIBXL_DOMAIN_TYPE_HVM:
     {
-        libxl_device_console console;
+        libxl__device_console console;
         libxl_device_vkb vkb;
 
         ret = init_console_info(&console, 0);
         if ( ret )
             goto error_out;
         libxl__device_console_add(gc, domid, &console, &state);
-        libxl_device_console_dispose(&console);
+        libxl__device_console_dispose(&console);
 
-        ret = libxl_device_vkb_init(ctx, &vkb);
-        if ( ret )
-            goto error_out;
+        libxl_device_vkb_init(&vkb);
         libxl_device_vkb_add(ctx, domid, &vkb);
         libxl_device_vkb_dispose(&vkb);
 
@@ -561,7 +627,7 @@ static int do_domain_create(libxl__gc *gc, libxl_domain_config *d_config,
     case LIBXL_DOMAIN_TYPE_PV:
     {
         int need_qemu = 0;
-        libxl_device_console console;
+        libxl__device_console console;
 
         for (i = 0; i < d_config->num_vfbs; i++) {
             libxl_device_vfb_add(ctx, domid, &d_config->vfbs[i]);
@@ -577,10 +643,10 @@ static int do_domain_create(libxl__gc *gc, libxl_domain_config *d_config,
                 d_config->num_disks, &d_config->disks[0]);
 
         if (need_qemu)
-             console.consback = LIBXL_CONSOLE_BACKEND_IOEMU;
+             console.consback = LIBXL__CONSOLE_BACKEND_IOEMU;
 
         libxl__device_console_add(gc, domid, &console, &state);
-        libxl_device_console_dispose(&console);
+        libxl__device_console_dispose(&console);
 
         if (need_qemu) {
             libxl__create_xenpv_qemu(gc, domid, d_config, &state, &dm_starting);
@@ -619,7 +685,7 @@ static int do_domain_create(libxl__gc *gc, libxl_domain_config *d_config,
     }
 
     if (d_config->c_info.type == LIBXL_DOMAIN_TYPE_PV &&
-        d_config->b_info.u.pv.e820_host) {
+        libxl_defbool_val(d_config->b_info.u.pv.e820_host)) {
         int rc;
         rc = libxl__e820_alloc(gc, domid, d_config);
         if (rc)
diff --git a/tools/libxl/libxl_dm.c b/tools/libxl/libxl_dm.c
index d007bab24b..1261499477 100644
--- a/tools/libxl/libxl_dm.c
+++ b/tools/libxl/libxl_dm.c
@@ -39,7 +39,7 @@ const char *libxl__domain_device_model(libxl__gc *gc,
     libxl_ctx *ctx = libxl__gc_owner(gc);
     const char *dm;
 
-    if (info->device_model_stubdomain)
+    if (libxl_defbool_val(info->device_model_stubdomain))
         return NULL;
 
     if (info->device_model) {
@@ -63,18 +63,6 @@ const char *libxl__domain_device_model(libxl__gc *gc,
     return dm;
 }
 
-static const char *libxl__domain_bios(libxl__gc *gc,
-                                const libxl_domain_build_info *info)
-{
-    if (info->u.hvm.bios)
-       return libxl_bios_type_to_string(info->u.hvm.bios);
-    switch (info->device_model_version) {
-    case 1: return "rombios";
-    case 2: return "seabios";
-    default:return NULL;
-    }
-}
-
 const libxl_vnc_info *libxl__dm_vnc(const libxl_domain_config *guest_config)
 {
     const libxl_vnc_info *vnc = NULL;
@@ -83,7 +71,7 @@ const libxl_vnc_info *libxl__dm_vnc(const libxl_domain_config *guest_config)
     } else if (guest_config->num_vfbs > 0) {
         vnc = &guest_config->vfbs[0].vnc;
     }
-    return vnc && vnc->enable ? vnc : NULL;
+    return vnc && libxl_defbool_val(vnc->enable) ? vnc : NULL;
 }
 
 static const libxl_sdl_info *dm_sdl(const libxl_domain_config *guest_config)
@@ -94,7 +82,7 @@ static const libxl_sdl_info *dm_sdl(const libxl_domain_config *guest_config)
     } else if (guest_config->num_vfbs > 0) {
         sdl = &guest_config->vfbs[0].sdl;
     }
-    return sdl && sdl->enable ? sdl : NULL;
+    return sdl && libxl_defbool_val(sdl->enable) ? sdl : NULL;
 }
 
 static const char *dm_keymap(const libxl_domain_config *guest_config)
@@ -156,13 +144,13 @@ static char ** libxl__build_device_model_args_old(libxl__gc *gc,
         flexarray_append(dm_args, "-vnc");
         flexarray_append(dm_args, vncarg);
 
-        if (vnc->findunused) {
+        if (libxl_defbool_val(vnc->findunused)) {
             flexarray_append(dm_args, "-vncunused");
         }
     }
     if (sdl) {
         flexarray_append(dm_args, "-sdl");
-        if (!sdl->opengl) {
+        if (!libxl_defbool_val(sdl->opengl)) {
             flexarray_append(dm_args, "-disable-opengl");
         }
         /* XXX sdl->{display,xauthority} into $DISPLAY/$XAUTHORITY */
@@ -177,7 +165,7 @@ static char ** libxl__build_device_model_args_old(libxl__gc *gc,
             flexarray_vappend(dm_args, "-serial", b_info->u.hvm.serial, NULL);
         }
 
-        if (b_info->u.hvm.nographic && (!sdl && !vnc)) {
+        if (libxl_defbool_val(b_info->u.hvm.nographic) && (!sdl && !vnc)) {
             flexarray_append(dm_args, "-nographic");
         }
 
@@ -187,14 +175,14 @@ static char ** libxl__build_device_model_args_old(libxl__gc *gc,
                                    libxl__sizekb_to_mb(b_info->video_memkb)),
                     NULL);
         }
-        if (b_info->u.hvm.stdvga) {
+        if (libxl_defbool_val(b_info->u.hvm.stdvga)) {
             flexarray_append(dm_args, "-std-vga");
         }
 
         if (b_info->u.hvm.boot) {
             flexarray_vappend(dm_args, "-boot", b_info->u.hvm.boot, NULL);
         }
-        if (b_info->u.hvm.usb || b_info->u.hvm.usbdevice) {
+        if (libxl_defbool_val(b_info->u.hvm.usb) || b_info->u.hvm.usbdevice) {
             flexarray_append(dm_args, "-usb");
             if (b_info->u.hvm.usbdevice) {
                 flexarray_vappend(dm_args,
@@ -204,7 +192,7 @@ static char ** libxl__build_device_model_args_old(libxl__gc *gc,
         if (b_info->u.hvm.soundhw) {
             flexarray_vappend(dm_args, "-soundhw", b_info->u.hvm.soundhw, NULL);
         }
-        if (b_info->u.hvm.acpi) {
+        if (libxl_defbool_val(b_info->u.hvm.acpi)) {
             flexarray_append(dm_args, "-acpi");
         }
         if (b_info->max_vcpus > 1) {
@@ -240,7 +228,7 @@ static char ** libxl__build_device_model_args_old(libxl__gc *gc,
         if ( ioemu_vifs == 0 ) {
             flexarray_vappend(dm_args, "-net", "none", NULL);
         }
-        if (b_info->u.hvm.gfx_passthru) {
+        if (libxl_defbool_val(b_info->u.hvm.gfx_passthru)) {
             flexarray_append(dm_args, "-gfx_passthru");
         }
     } else {
@@ -293,7 +281,7 @@ static char *dm_spice_options(libxl__gc *gc,
         return NULL;
     }
 
-    if (!spice->disable_ticketing) {
+    if (!libxl_defbool_val(spice->disable_ticketing)) {
         if (!spice->passwd) {
             LIBXL__LOG(CTX, LIBXL__LOG_ERROR,
                        "spice ticketing is enabled but missing password");
@@ -309,12 +297,12 @@ static char *dm_spice_options(libxl__gc *gc,
                          spice->port, spice->tls_port);
     if (spice->host)
         opt = libxl__sprintf(gc, "%s,addr=%s", opt, spice->host);
-    if (spice->disable_ticketing)
+    if (libxl_defbool_val(spice->disable_ticketing))
         opt = libxl__sprintf(gc, "%s,disable-ticketing", opt);
     else
         opt = libxl__sprintf(gc, "%s,password=%s", opt, spice->passwd);
     opt = libxl__sprintf(gc, "%s,agent-mouse=%s", opt,
-                         spice->agent_mouse ? "on" : "off");
+                         libxl_defbool_val(spice->agent_mouse) ? "on" : "off");
     return opt;
 }
 
@@ -383,7 +371,7 @@ static char ** libxl__build_device_model_args_new(libxl__gc *gc,
         if (vnc->passwd && vnc->passwd[0]) {
             vncarg = libxl__sprintf(gc, "%s,password", vncarg);
         }
-        if (vnc->findunused) {
+        if (libxl_defbool_val(vnc->findunused)) {
             /* This option asks to QEMU to try this number of port before to
              * give up.  So QEMU will try ports between $display and $display +
              * 99.  This option needs to be the last one of the vnc options. */
@@ -411,11 +399,11 @@ static char ** libxl__build_device_model_args_new(libxl__gc *gc,
             flexarray_vappend(dm_args, "-serial", b_info->u.hvm.serial, NULL);
         }
 
-        if (b_info->u.hvm.nographic && (!sdl && !vnc)) {
+        if (libxl_defbool_val(b_info->u.hvm.nographic) && (!sdl && !vnc)) {
             flexarray_append(dm_args, "-nographic");
         }
 
-        if (b_info->u.hvm.spice.enable) {
+        if (libxl_defbool_val(b_info->u.hvm.spice.enable)) {
             const libxl_spice_info *spice = &b_info->u.hvm.spice;
             char *spiceoptions = dm_spice_options(gc, spice);
             if (!spiceoptions)
@@ -425,7 +413,7 @@ static char ** libxl__build_device_model_args_new(libxl__gc *gc,
             flexarray_append(dm_args, spiceoptions);
         }
 
-        if (b_info->u.hvm.stdvga) {
+        if (libxl_defbool_val(b_info->u.hvm.stdvga)) {
                 flexarray_vappend(dm_args, "-vga", "std", NULL);
         }
 
@@ -433,7 +421,7 @@ static char ** libxl__build_device_model_args_new(libxl__gc *gc,
             flexarray_vappend(dm_args, "-boot",
                     libxl__sprintf(gc, "order=%s", b_info->u.hvm.boot), NULL);
         }
-        if (b_info->u.hvm.usb || b_info->u.hvm.usbdevice) {
+        if (libxl_defbool_val(b_info->u.hvm.usb) || b_info->u.hvm.usbdevice) {
             flexarray_append(dm_args, "-usb");
             if (b_info->u.hvm.usbdevice) {
                 flexarray_vappend(dm_args,
@@ -443,7 +431,7 @@ static char ** libxl__build_device_model_args_new(libxl__gc *gc,
         if (b_info->u.hvm.soundhw) {
             flexarray_vappend(dm_args, "-soundhw", b_info->u.hvm.soundhw, NULL);
         }
-        if (!b_info->u.hvm.acpi) {
+        if (!libxl_defbool_val(b_info->u.hvm.acpi)) {
             flexarray_append(dm_args, "-no-acpi");
         }
         if (b_info->max_vcpus > 1) {
@@ -485,7 +473,7 @@ static char ** libxl__build_device_model_args_new(libxl__gc *gc,
             flexarray_append(dm_args, "-net");
             flexarray_append(dm_args, "none");
         }
-        if (b_info->u.hvm.gfx_passthru) {
+        if (libxl_defbool_val(b_info->u.hvm.gfx_passthru)) {
             flexarray_append(dm_args, "-gfx_passthru");
         }
     } else {
@@ -616,8 +604,8 @@ static int libxl__vfb_and_vkb_from_hvm_guest_config(libxl__gc *gc,
     if (b_info->type != LIBXL_DOMAIN_TYPE_HVM)
         return ERROR_INVAL;
 
-    memset(vfb, 0x00, sizeof(libxl_device_vfb));
-    memset(vkb, 0x00, sizeof(libxl_device_vkb));
+    libxl_device_vfb_init(vfb);
+    libxl_device_vkb_init(vkb);
 
     vfb->backend_domid = 0;
     vfb->devid = 0;
@@ -688,7 +676,7 @@ static int libxl__create_stubdom(libxl__gc *gc,
 {
     libxl_ctx *ctx = libxl__gc_owner(gc);
     int i, num_console = STUBDOM_SPECIAL_CONSOLES, ret;
-    libxl_device_console *console;
+    libxl__device_console *console;
     libxl_domain_config dm_config;
     libxl_device_vfb vfb;
     libxl_device_vkb vkb;
@@ -705,7 +693,7 @@ static int libxl__create_stubdom(libxl__gc *gc,
         goto out;
     }
 
-    memset(&dm_config.c_info, 0x00, sizeof(libxl_domain_create_info));
+    libxl_domain_create_info_init(&dm_config.c_info);
     dm_config.c_info.type = LIBXL_DOMAIN_TYPE_PV;
     dm_config.c_info.name = libxl__sprintf(gc, "%s-dm",
                                     libxl__domid_to_name(gc, guest_domid));
@@ -713,13 +701,13 @@ static int libxl__create_stubdom(libxl__gc *gc,
 
     libxl_uuid_generate(&dm_config.c_info.uuid);
 
-    memset(&dm_config.b_info, 0x00, sizeof(libxl_domain_build_info));
-    dm_config.b_info.type = dm_config.c_info.type;
+    libxl_domain_build_info_init(&dm_config.b_info);
+    libxl_domain_build_info_init_type(&dm_config.b_info, LIBXL_DOMAIN_TYPE_PV);
+
     dm_config.b_info.max_vcpus = 1;
     dm_config.b_info.max_memkb = 32 * 1024;
     dm_config.b_info.target_memkb = dm_config.b_info.max_memkb;
 
-    dm_config.b_info.type = LIBXL_DOMAIN_TYPE_PV;
     dm_config.b_info.u.pv.kernel.path = libxl__abs_path(gc, "ioemu-stubdom.gz",
                                               libxl_xenfirmwaredir_path());
     dm_config.b_info.u.pv.cmdline = libxl__sprintf(gc, " -d %d", guest_domid);
@@ -740,6 +728,11 @@ static int libxl__create_stubdom(libxl__gc *gc,
     dm_config.vifs = guest_config->vifs;
     dm_config.num_vifs = guest_config->num_vifs;
 
+    ret = libxl__domain_create_info_setdefault(gc, &dm_config.c_info);
+    if (ret) goto out;
+    ret = libxl__domain_build_info_setdefault(gc, &dm_config.b_info);
+    if (ret) goto out;
+
     libxl__vfb_and_vkb_from_hvm_guest_config(gc, guest_config, &vfb, &vkb);
     dm_config.vfbs = &vfb;
     dm_config.num_vfbs = 1;
@@ -816,7 +809,7 @@ retry_transaction:
     if (guest_config->b_info.u.hvm.serial)
         num_console++;
 
-    console = libxl__calloc(gc, num_console, sizeof(libxl_device_console));
+    console = libxl__calloc(gc, num_console, sizeof(libxl__device_console));
     if (!console) {
         ret = ERROR_NOMEM;
         goto out_free;
@@ -824,7 +817,7 @@ retry_transaction:
 
     for (i = 0; i < num_console; i++) {
         console[i].devid = i;
-        console[i].consback = LIBXL_CONSOLE_BACKEND_IOEMU;
+        console[i].consback = LIBXL__CONSOLE_BACKEND_IOEMU;
         /* STUBDOM_CONSOLE_LOGGING (console 0) is for minios logging
          * STUBDOM_CONSOLE_SAVE (console 1) is for writing the save file
          * STUBDOM_CONSOLE_RESTORE (console 2) is for reading the save file
@@ -907,7 +900,7 @@ int libxl__create_device_model(libxl__gc *gc,
     char **pass_stuff;
     const char *dm;
 
-    if (b_info->device_model_stubdomain) {
+    if (libxl_defbool_val(b_info->device_model_stubdomain)) {
         rc = libxl__create_stubdom(gc, domid, guest_config, state, starting_r);
         goto out;
     }
@@ -929,10 +922,13 @@ int libxl__create_device_model(libxl__gc *gc,
         goto out;
     }
 
-    path = xs_get_domain_path(ctx->xsh, domid);
-    libxl__xs_write(gc, XBT_NULL, libxl__sprintf(gc, "%s/hvmloader/bios", path),
-                    "%s", libxl__domain_bios(gc, b_info));
-    free(path);
+    if (b_info->type == LIBXL_DOMAIN_TYPE_HVM) {
+        path = xs_get_domain_path(ctx->xsh, domid);
+        libxl__xs_write(gc, XBT_NULL,
+                        libxl__sprintf(gc, "%s/hvmloader/bios", path),
+                        "%s", libxl_bios_type_to_string(b_info->u.hvm.bios));
+        free(path);
+    }
 
     path = libxl__sprintf(gc, "/local/domain/0/device-model/%d", domid);
     xs_mkdir(ctx->xsh, XBT_NULL, path);
@@ -941,7 +937,7 @@ int libxl__create_device_model(libxl__gc *gc,
         b_info->device_model_version
         == LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN_TRADITIONAL)
         libxl__xs_write(gc, XBT_NULL, libxl__sprintf(gc, "%s/disable_pf", path),
-                        "%d", !b_info->u.hvm.xen_platform_pci);
+                    "%d", !libxl_defbool_val(b_info->u.hvm.xen_platform_pci));
 
     libxl_create_logfile(ctx,
                          libxl__sprintf(gc, "qemu-dm-%s", c_info->name),
@@ -1088,7 +1084,7 @@ out:
 }
 
 int libxl__need_xenpv_qemu(libxl__gc *gc,
-        int nr_consoles, libxl_device_console *consoles,
+        int nr_consoles, libxl__device_console *consoles,
         int nr_vfbs, libxl_device_vfb *vfbs,
         int nr_disks, libxl_device_disk *disks)
 {
@@ -1100,7 +1096,7 @@ int libxl__need_xenpv_qemu(libxl__gc *gc,
     }
 
     for (i = 0; i < nr_consoles; i++) {
-        if (consoles[i].consback == LIBXL_CONSOLE_BACKEND_IOEMU) {
+        if (consoles[i].consback == LIBXL__CONSOLE_BACKEND_IOEMU) {
             ret = 1;
             goto out;
         }
diff --git a/tools/libxl/libxl_dom.c b/tools/libxl/libxl_dom.c
index 60ed1d55ad..9b33267353 100644
--- a/tools/libxl/libxl_dom.c
+++ b/tools/libxl/libxl_dom.c
@@ -88,7 +88,7 @@ int libxl__build_pre(libxl__gc *gc, uint32_t domid,
         abort();
     }
     xc_domain_set_tsc_info(ctx->xch, domid, tsc_mode, 0, 0, 0);
-    if ( info->disable_migrate )
+    if (libxl_defbool_val(info->disable_migrate))
         xc_domain_disable_migrate(ctx->xch, domid);
 
     if (info->type == LIBXL_DOMAIN_TYPE_HVM) {
@@ -129,11 +129,12 @@ int libxl__build_post(libxl__gc *gc, uint32_t domid,
 
     ents = libxl__calloc(gc, 12 + (info->max_vcpus * 2) + 2, sizeof(char *));
     ents[0] = "memory/static-max";
-    ents[1] = libxl__sprintf(gc, "%d", info->max_memkb);
+    ents[1] = libxl__sprintf(gc, "%"PRId64, info->max_memkb);
     ents[2] = "memory/target";
-    ents[3] = libxl__sprintf(gc, "%d", info->target_memkb - info->video_memkb);
+    ents[3] = libxl__sprintf(gc, "%"PRId64,
+                             info->target_memkb - info->video_memkb);
     ents[4] = "memory/videoram";
-    ents[5] = libxl__sprintf(gc, "%d", info->video_memkb);
+    ents[5] = libxl__sprintf(gc, "%"PRId64, info->video_memkb);
     ents[6] = "domid";
     ents[7] = libxl__sprintf(gc, "%d", domid);
     ents[8] = "store/port";
@@ -291,7 +292,7 @@ static int hvm_build_set_params(xc_interface *handle, uint32_t domid,
         return -1;
 
     va_hvm = (struct hvm_info_table *)(va_map + HVM_INFO_OFFSET);
-    va_hvm->apic_mode = info->u.hvm.apic;
+    va_hvm->apic_mode = libxl_defbool_val(info->u.hvm.apic);
     va_hvm->nr_vcpus = info->max_vcpus;
     memcpy(va_hvm->vcpu_online, &info->cur_vcpus, sizeof(info->cur_vcpus));
     for (i = 0, sum = 0; i < va_hvm->length; i++)
@@ -301,14 +302,19 @@ static int hvm_build_set_params(xc_interface *handle, uint32_t domid,
 
     xc_get_hvm_param(handle, domid, HVM_PARAM_STORE_PFN, store_mfn);
     xc_get_hvm_param(handle, domid, HVM_PARAM_CONSOLE_PFN, console_mfn);
-    xc_set_hvm_param(handle, domid, HVM_PARAM_PAE_ENABLED, info->u.hvm.pae);
+    xc_set_hvm_param(handle, domid, HVM_PARAM_PAE_ENABLED,
+                     libxl_defbool_val(info->u.hvm.pae));
 #if defined(__i386__) || defined(__x86_64__)
-    xc_set_hvm_param(handle, domid, HVM_PARAM_VIRIDIAN, info->u.hvm.viridian);
-    xc_set_hvm_param(handle, domid, HVM_PARAM_HPET_ENABLED, (unsigned long) info->u.hvm.hpet);
+    xc_set_hvm_param(handle, domid, HVM_PARAM_VIRIDIAN,
+                     libxl_defbool_val(info->u.hvm.viridian));
+    xc_set_hvm_param(handle, domid, HVM_PARAM_HPET_ENABLED,
+                     libxl_defbool_val(info->u.hvm.hpet));
 #endif
     xc_set_hvm_param(handle, domid, HVM_PARAM_TIMER_MODE, timer_mode(info));
-    xc_set_hvm_param(handle, domid, HVM_PARAM_VPT_ALIGN, (unsigned long) info->u.hvm.vpt_align);
-    xc_set_hvm_param(handle, domid, HVM_PARAM_NESTEDHVM, info->u.hvm.nested_hvm);
+    xc_set_hvm_param(handle, domid, HVM_PARAM_VPT_ALIGN,
+                     libxl_defbool_val(info->u.hvm.vpt_align));
+    xc_set_hvm_param(handle, domid, HVM_PARAM_NESTEDHVM,
+                     libxl_defbool_val(info->u.hvm.nested_hvm));
     xc_set_hvm_param(handle, domid, HVM_PARAM_STORE_EVTCHN, store_evtchn);
     xc_set_hvm_param(handle, domid, HVM_PARAM_CONSOLE_EVTCHN, console_evtchn);
 
@@ -399,8 +405,8 @@ int libxl__domain_restore_common(libxl__gc *gc, uint32_t domid,
     case LIBXL_DOMAIN_TYPE_HVM:
         hvm = 1;
         superpages = 1;
-        pae = info->u.hvm.pae;
-        no_incr_generationid = info->u.hvm.no_incr_generationid;
+        pae = libxl_defbool_val(info->u.hvm.pae);
+        no_incr_generationid = !libxl_defbool_val(info->u.hvm.incr_generationid);
         break;
     case LIBXL_DOMAIN_TYPE_PV:
         hvm = 0;
diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h
index 46e131abc7..e0a1070dd9 100644
--- a/tools/libxl/libxl_internal.h
+++ b/tools/libxl/libxl_internal.h
@@ -187,6 +187,16 @@ libxl__ev_xswatch *libxl__watch_slot_contents(libxl__gc *gc, int slotnum);
  * version of the _evdisable_FOO function; the internal one is
  * used during cleanup.
  */
+_hidden int libxl__domain_create_info_setdefault(libxl__gc *gc,
+                                        libxl_domain_create_info *c_info);
+_hidden int libxl__domain_build_info_setdefault(libxl__gc *gc,
+                                        libxl_domain_build_info *b_info);
+_hidden int libxl__device_disk_setdefault(libxl__gc *gc,
+                                          libxl_device_disk *disk);
+_hidden int libxl__device_nic_setdefault(libxl__gc *gc, libxl_device_nic *nic);
+_hidden int libxl__device_vfb_setdefault(libxl__gc *gc, libxl_device_vfb *vfb);
+_hidden int libxl__device_vkb_setdefault(libxl__gc *gc, libxl_device_vkb *vkb);
+_hidden int libxl__device_pci_setdefault(libxl__gc *gc, libxl_device_pci *pci);
 
 struct libxl__evgen_domain_death {
     uint32_t domid;
@@ -652,7 +662,7 @@ _hidden int libxl__device_disk_dev_number(const char *virtpath,
                                           int *pdisk, int *ppartition);
 
 _hidden int libxl__device_console_add(libxl__gc *gc, uint32_t domid,
-                                      libxl_device_console *console,
+                                      libxl__device_console *console,
                                       libxl__domain_build_state *state);
 
 _hidden int libxl__device_generic_add(libxl__gc *gc, libxl__device *device,
@@ -665,6 +675,19 @@ _hidden int libxl__device_destroy(libxl__gc *gc, libxl__device *dev);
 _hidden int libxl__devices_destroy(libxl__gc *gc, uint32_t domid);
 _hidden int libxl__wait_for_backend(libxl__gc *gc, char *be_path, char *state);
 
+/*
+ * For each aggregate type which can be used as an input we provide:
+ *
+ * int libxl__<type>_setdefault(gc, <type> *p):
+ *
+ *     Idempotently sets any members of "p" which is currently set to
+ *     a special value indicating that the defaults should be used
+ *     (per libxl_<type>_init) to a specific value.
+ *
+ *     All libxl API functions are expected to have arranged for this
+ *     to be called before using any values within these structures.
+ */
+
 /* Arranges that dev will be removed from its guest.  When
  * this is done, the ao will be completed.  An error
  * return from libxl__initiate_device_remove means that the ao
@@ -882,7 +905,7 @@ _hidden int libxl__create_xenpv_qemu(libxl__gc *gc, uint32_t domid,
                               libxl__domain_build_state *state,
                               libxl__spawner_starting **starting_r);
 _hidden int libxl__need_xenpv_qemu(libxl__gc *gc,
-        int nr_consoles, libxl_device_console *consoles,
+        int nr_consoles, libxl__device_console *consoles,
         int nr_vfbs, libxl_device_vfb *vfbs,
         int nr_disks, libxl_device_disk *disks);
   /* Caller must either: pass starting_r==0, or on successful
diff --git a/tools/libxl/libxl_json.c b/tools/libxl/libxl_json.c
index 70909fbd0f..7c068d3e81 100644
--- a/tools/libxl/libxl_json.c
+++ b/tools/libxl/libxl_json.c
@@ -85,6 +85,12 @@ yajl_gen_status libxl__yajl_gen_enum(yajl_gen hand, const char *str)
 /*
  * YAJL generators for builtin libxl types.
  */
+yajl_gen_status libxl_defbool_gen_json(yajl_gen hand,
+                                       libxl_defbool *db)
+{
+    return libxl__yajl_gen_asciiz(hand, libxl_defbool_to_string(*db));
+}
+
 yajl_gen_status libxl_uuid_gen_json(yajl_gen hand,
                                     libxl_uuid *uuid)
 {
diff --git a/tools/libxl/libxl_json.h b/tools/libxl/libxl_json.h
index 1d183c5ef9..0e3836e5f2 100644
--- a/tools/libxl/libxl_json.h
+++ b/tools/libxl/libxl_json.h
@@ -22,6 +22,20 @@
 #  include <yajl/yajl_version.h>
 #endif
 
+yajl_gen_status libxl_defbool_gen_json(yajl_gen hand, libxl_defbool *p);
+yajl_gen_status libxl_domid_gen_json(yajl_gen hand, libxl_domid *p);
+yajl_gen_status libxl_uuid_gen_json(yajl_gen hand, libxl_uuid *p);
+yajl_gen_status libxl_mac_gen_json(yajl_gen hand, libxl_mac *p);
+yajl_gen_status libxl_cpumap_gen_json(yajl_gen hand, libxl_cpumap *p);
+yajl_gen_status libxl_cpuid_policy_list_gen_json(yajl_gen hand,
+                                                 libxl_cpuid_policy_list *p);
+yajl_gen_status libxl_string_list_gen_json(yajl_gen hand, libxl_string_list *p);
+yajl_gen_status libxl_key_value_list_gen_json(yajl_gen hand,
+                                              libxl_key_value_list *p);
+yajl_gen_status libxl_file_reference_gen_json(yajl_gen hand,
+                                              libxl_file_reference *p);
+yajl_gen_status libxl_hwcap_gen_json(yajl_gen hand, libxl_hwcap *p);
+
 #include <_libxl_types_json.h>
 
 /* YAJL version check */
diff --git a/tools/libxl/libxl_pci.c b/tools/libxl/libxl_pci.c
index 33425f5fe9..4175ac3ef3 100644
--- a/tools/libxl/libxl_pci.c
+++ b/tools/libxl/libxl_pci.c
@@ -765,6 +765,11 @@ static int libxl__device_pci_reset(libxl__gc *gc, unsigned int domain, unsigned
     return -1;
 }
 
+int libxl__device_pci_setdefault(libxl__gc *gc, libxl_device_pci *pci)
+{
+    return 0;
+}
+
 int libxl_device_pci_add(libxl_ctx *ctx, uint32_t domid, libxl_device_pci *pcidev)
 {
     GC_INIT(ctx);
@@ -782,6 +787,9 @@ int libxl__device_pci_add(libxl__gc *gc, uint32_t domid, libxl_device_pci *pcide
     int num_assigned, i, rc;
     int stubdomid = 0;
 
+    rc = libxl__device_pci_setdefault(gc, pcidev);
+    if (rc) goto out;
+
     rc = get_all_assigned_devices(gc, &assigned, &num_assigned);
     if ( rc ) {
         LIBXL__LOG(ctx, LIBXL__LOG_ERROR, "cannot determine if device is assigned, refusing to continue");
@@ -1365,7 +1373,7 @@ int libxl__e820_alloc(libxl__gc *gc, uint32_t domid, libxl_domain_config *d_conf
         return ERROR_INVAL;
 
     b_info = &d_config->b_info;
-    if (!b_info->u.pv.e820_host)
+    if (!libxl_defbool_val(b_info->u.pv.e820_host))
         return ERROR_INVAL;
 
     rc = xc_get_machine_memory_map(ctx->xch, map, E820MAX);
diff --git a/tools/libxl/libxl_types.idl b/tools/libxl/libxl_types.idl
index d6554b3074..64e5a38fe2 100644
--- a/tools/libxl/libxl_types.idl
+++ b/tools/libxl/libxl_types.idl
@@ -5,6 +5,8 @@
 
 namespace("libxl_")
 
+libxl_defbool = Builtin("defbool", passby=PASS_BY_REFERENCE)
+
 libxl_domid = Builtin("domid", json_fn = "yajl_gen_integer", autogenerate_json = False)
 libxl_uuid = Builtin("uuid", passby=PASS_BY_REFERENCE)
 libxl_mac = Builtin("mac", passby=PASS_BY_REFERENCE)
@@ -18,6 +20,12 @@ libxl_file_reference = Builtin("file_reference", dispose_fn="libxl_file_referenc
 libxl_hwcap = Builtin("hwcap", passby=PASS_BY_REFERENCE)
 
 #
+# Specific integer types
+#
+
+MemKB = UInt(64, init_val = "LIBXL_MEMKB_DEFAULT")
+
+#
 # Constants / Enumerations
 #
 
@@ -36,11 +44,6 @@ libxl_console_type = Enumeration("console_type", [
     (2, "PV"),
     ])
 
-libxl_console_backend = Enumeration("console_backend", [
-    (1, "XENCONSOLED"),
-    (2, "IOEMU"),
-    ])
-
 libxl_disk_format = Enumeration("disk_format", [
     (0, "UNKNOWN"),
     (1, "QCOW"),
@@ -97,7 +100,7 @@ libxl_timer_mode = Enumeration("timer_mode", [
     (1, "no_delay_for_missed_ticks"),
     (2, "no_missed_ticks_pending"),
     (3, "one_missed_tick_pending"),
-    ])
+    ], init_val = "LIBXL_TIMER_MODE_DEFAULT")
 
 libxl_bios_type = Enumeration("bios_type", [
     (1, "rombios"),
@@ -105,35 +108,52 @@ libxl_bios_type = Enumeration("bios_type", [
     (3, "ovmf"),
     ])
 
+# Consistent with values defined in domctl.h
+libxl_scheduler = Enumeration("scheduler", [
+    (4, "sedf"),
+    (5, "credit"),
+    (6, "credit2"),
+    (7, "arinc653"),
+    ])
+
+# Consistent with SHUTDOWN_* in sched.h
+libxl_shutdown_reason = Enumeration("shutdown_reason", [
+    (0, "poweroff"),
+    (1, "reboot"),
+    (2, "suspend"),
+    (3, "crash"),
+    (4, "watchdog"),
+    ])
+
 #
 # Complex libxl types
 #
 libxl_vnc_info = Struct("vnc_info", [
-    ("enable",        bool),
+    ("enable",        libxl_defbool),
     # "address:port" that should be listened on
     ("listen",        string),
     ("passwd",        string),
     ("display",       integer),
     # If set then try to find an unused port
-    ("findunused",    bool),
+    ("findunused",    libxl_defbool),
     ])
 
 libxl_spice_info = Struct("spice_info", [
-    ("enable",            bool),
+    ("enable",      libxl_defbool),
     # At least one of spice port or spicetls_post must be given
     ("port",        integer),
     ("tls_port",    integer),
     # Interface to bind to
     ("host",        string),
     # enable client connection with no password
-    ("disable_ticketing", bool),
+    ("disable_ticketing", libxl_defbool),
     ("passwd",      string),
-    ("agent_mouse", bool),
+    ("agent_mouse", libxl_defbool),
     ])
 
 libxl_sdl_info = Struct("sdl_info", [
-    ("enable",        bool),
-    ("opengl",        bool),
+    ("enable",        libxl_defbool),
+    ("opengl",        libxl_defbool),
     ("display",       string),
     ("xauthority",    string),
     ])
@@ -148,31 +168,31 @@ libxl_dominfo = Struct("dominfo",[
     ("shutdown",    bool),
     ("dying",       bool),
 
-    # Valid SHUTDOWN_* value from xen/sched.h iff (shutdown||dying).
+    # Valid iff (shutdown||dying).
     #
     # Otherwise set to a value guaranteed not to clash with any valid
-    # SHUTDOWN_* constant.
-    ("shutdown_reason", uint8),
-    ("current_memkb",   uint64),
-    ("shared_memkb", uint64),
-    ("max_memkb",   uint64),
+    # LIBXL_SHUTDOWN_REASON_* constant.
+    ("shutdown_reason", libxl_shutdown_reason),
+    ("current_memkb",   MemKB),
+    ("shared_memkb", MemKB),
+    ("max_memkb",   MemKB),
     ("cpu_time",    uint64),
     ("vcpu_max_id", uint32),
     ("vcpu_online", uint32),
     ("cpupool",     uint32),
-    ], dispose_fn=None)
+    ], dir=DIR_OUT)
 
 libxl_cpupoolinfo = Struct("cpupoolinfo", [
     ("poolid",      uint32),
-    ("sched_id",    uint32),
+    ("sched",       libxl_scheduler),
     ("n_dom",       uint32),
     ("cpumap",      libxl_cpumap)
-    ])
+    ], dir=DIR_OUT)
 
 libxl_vminfo = Struct("vminfo", [
     ("uuid", libxl_uuid),
     ("domid", libxl_domid),
-    ], dispose_fn=None)
+    ], dir=DIR_OUT)
 
 libxl_version_info = Struct("version_info", [
     ("xen_version_major", integer),
@@ -187,19 +207,21 @@ libxl_version_info = Struct("version_info", [
     ("virt_start",        uint64),
     ("pagesize",          integer),
     ("commandline",       string),
-    ])
+    ], dir=DIR_OUT)
 
 libxl_domain_create_info = Struct("domain_create_info",[
     ("type",         libxl_domain_type),
-    ("hap",          bool),
-    ("oos",          bool),
+    ("hap",          libxl_defbool),
+    ("oos",          libxl_defbool),
     ("ssidref",      uint32),
     ("name",         string),
     ("uuid",         libxl_uuid),
     ("xsdata",       libxl_key_value_list),
     ("platformdata", libxl_key_value_list),
     ("poolid",       uint32),
-    ])
+    ], dir=DIR_IN)
+
+MemKB = UInt(64, init_val = "LIBXL_MEMKB_DEFAULT")
 
 # Instances of libxl_file_reference contained in this struct which
 # have been mapped (with libxl_file_reference_map) will be unmapped
@@ -211,17 +233,16 @@ libxl_domain_build_info = Struct("domain_build_info",[
     ("cur_vcpus",       integer),
     ("cpumap",          libxl_cpumap),
     ("tsc_mode",        libxl_tsc_mode),
-    ("max_memkb",       uint32),
-    ("target_memkb",    uint32),
-    ("video_memkb",     uint32),
-    ("shadow_memkb",    uint32),
-    ("disable_migrate", bool),
+    ("max_memkb",       MemKB),
+    ("target_memkb",    MemKB),
+    ("video_memkb",     MemKB),
+    ("shadow_memkb",    MemKB),
+    ("disable_migrate", libxl_defbool),
     ("cpuid",           libxl_cpuid_policy_list),
-    ("type",            libxl_domain_type),
     
     ("device_model_version", libxl_device_model_version),
-    ("device_model_stubdomain", bool),
-    # you set device_model you must set device_model_version too
+    ("device_model_stubdomain", libxl_defbool),
+    # if you set device_model you must set device_model_version too
     ("device_model",     string),
     ("device_model_ssidref", uint32),
 
@@ -233,53 +254,53 @@ libxl_domain_build_info = Struct("domain_build_info",[
     ("extra_hvm",        libxl_string_list),
 
     ("u", KeyedUnion(None, libxl_domain_type, "type",
-                [("hvm", Struct(None, [("firmware", string),
-                                       ("bios", libxl_bios_type),
-                                       ("pae", bool),
-                                       ("apic", bool),
-                                       ("acpi", bool),
-                                       ("acpi_s3", bool),
-                                       ("acpi_s4", bool),
-                                       ("nx", bool),
-                                       ("viridian", bool),
-                                       ("timeoffset", string),
-                                       ("hpet", bool),
-                                       ("vpt_align", bool),
-                                       ("timer_mode", libxl_timer_mode),
-                                       ("nested_hvm", bool),
-                                       ("no_incr_generationid", bool),
-                                       ("nographic",        bool),
-                                       ("stdvga",           bool),
+                [("hvm", Struct(None, [("firmware",         string),
+                                       ("bios",             libxl_bios_type),
+                                       ("pae",              libxl_defbool),
+                                       ("apic",             libxl_defbool),
+                                       ("acpi",             libxl_defbool),
+                                       ("acpi_s3",          libxl_defbool),
+                                       ("acpi_s4",          libxl_defbool),
+                                       ("nx",               libxl_defbool),
+                                       ("viridian",         libxl_defbool),
+                                       ("timeoffset",       string),
+                                       ("hpet",             libxl_defbool),
+                                       ("vpt_align",        libxl_defbool),
+                                       ("timer_mode",       libxl_timer_mode),
+                                       ("nested_hvm",       libxl_defbool),
+                                       ("incr_generationid",libxl_defbool),
+                                       ("nographic",        libxl_defbool),
+                                       ("stdvga",           libxl_defbool),
                                        ("vnc",              libxl_vnc_info),
                                        # keyboard layout, default is en-us keyboard
                                        ("keymap",           string),
                                        ("sdl",              libxl_sdl_info),
                                        ("spice",            libxl_spice_info),
                                        
-                                       ("gfx_passthru",     bool),
+                                       ("gfx_passthru",     libxl_defbool),
                                        
                                        ("serial",           string),
                                        ("boot",             string),
-                                       ("usb",              bool),
+                                       ("usb",              libxl_defbool),
                                        # usbdevice:
                                        # - "tablet" for absolute mouse,
                                        # - "mouse" for PS/2 protocol relative mouse
                                        ("usbdevice",        string),
                                        ("soundhw",          string),
-                                       ("xen_platform_pci", bool),
+                                       ("xen_platform_pci", libxl_defbool),
                                        ])),
                  ("pv", Struct(None, [("kernel", libxl_file_reference),
-                                      ("slack_memkb", uint32),
+                                      ("slack_memkb", MemKB),
                                       ("bootloader", string),
                                       ("bootloader_args", libxl_string_list),
                                       ("cmdline", string),
                                       ("ramdisk", libxl_file_reference),
                                       ("features", string, {'const': True}),
                                       # Use host's E820 for PCI passthrough.
-                                      ("e820_host", bool),
+                                      ("e820_host", libxl_defbool),
                                       ])),
-                 ])),
-    ],
+                 ], keyvar_init_val = "-1")),
+    ], dir=DIR_IN
 )
 
 libxl_device_vfb = Struct("device_vfb", [
@@ -296,13 +317,6 @@ libxl_device_vkb = Struct("device_vkb", [
     ("devid", integer),
     ])
 
-libxl_device_console = Struct("device_console", [
-    ("backend_domid", libxl_domid),
-    ("devid", integer),
-    ("consback", libxl_console_backend),
-    ("output", string),
-    ])
-
 libxl_device_disk = Struct("device_disk", [
     ("backend_domid", libxl_domid),
     ("pdev_path", string),
@@ -348,7 +362,7 @@ libxl_diskinfo = Struct("diskinfo", [
     ("state", integer),
     ("evtch", integer),
     ("rref", integer),
-    ])
+    ], dir=DIR_OUT)
 
 libxl_nicinfo = Struct("nicinfo", [
     ("backend", string),
@@ -360,7 +374,7 @@ libxl_nicinfo = Struct("nicinfo", [
     ("evtch", integer),
     ("rref_tx", integer),
     ("rref_rx", integer),
-    ])
+    ], dir=DIR_OUT)
 
 libxl_vcpuinfo = Struct("vcpuinfo", [
     ("vcpuid", uint32),
@@ -370,7 +384,7 @@ libxl_vcpuinfo = Struct("vcpuinfo", [
     ("running", bool),
     ("vcpu_time", uint64), # total vcpu time ran (ns)
     ("cpumap", libxl_cpumap), # current cpu's affinities
-    ])
+    ], dir=DIR_OUT)
 
 libxl_physinfo = Struct("physinfo", [
     ("threads_per_core", uint32),
@@ -388,23 +402,25 @@ libxl_physinfo = Struct("physinfo", [
 
     ("nr_nodes", uint32),
     ("hw_cap", libxl_hwcap),
-    ("phys_cap", uint32),
-    ], dispose_fn=None, dir=DIR_OUT)
+
+    ("cap_hvm", bool),
+    ("cap_hvm_directio", bool),
+    ], dir=DIR_OUT)
 
 libxl_cputopology = Struct("cputopology", [
     ("core", uint32),
     ("socket", uint32),
     ("node", uint32),
-    ])
+    ], dir=DIR_OUT)
 
 libxl_sched_credit_domain = Struct("sched_credit_domain", [
     ("weight", integer),
     ("cap", integer),
-    ], dispose_fn=None)
+    ])
 
 libxl_sched_credit2_domain = Struct("sched_credit2_domain", [
     ("weight", integer),
-    ], dispose_fn=None)
+    ])
 
 libxl_sched_sedf_domain = Struct("sched_sedf_domain", [
     ("period", integer),
@@ -412,7 +428,7 @@ libxl_sched_sedf_domain = Struct("sched_sedf_domain", [
     ("latency", integer),
     ("extratime", integer),
     ("weight", integer),
-    ], dispose_fn=None)
+    ])
 
 libxl_event_type = Enumeration("event_type", [
     (1, "DOMAIN_SHUTDOWN"),
@@ -432,7 +448,6 @@ libxl_event = Struct("event",[
     ("domid",    libxl_domid),
     ("domuuid",  libxl_uuid),
     ("for_user", libxl_ev_user),
-    ("type",     libxl_event_type),
     ("u", KeyedUnion(None, libxl_event_type, "type",
           [("domain_shutdown", Struct(None, [
                                              ("shutdown_reason", uint8),
diff --git a/tools/libxl/libxl_types_internal.idl b/tools/libxl/libxl_types_internal.idl
index 71e13a523d..15f33419d0 100644
--- a/tools/libxl/libxl_types_internal.idl
+++ b/tools/libxl/libxl_types_internal.idl
@@ -1,5 +1,7 @@
 namespace("libxl__")
 
+libxl_domid = Builtin("domid", namespace="libxl_", json_fn = "yajl_gen_integer")
+
 libxl__qmp_message_type = Enumeration("qmp_message_type", [
     (1, "QMP"),
     (2, "return"),
@@ -17,3 +19,15 @@ libxl__device_kind = Enumeration("device_kind", [
     (6, "VKBD"),
     (7, "CONSOLE"),
     ])
+
+libxl__console_backend = Enumeration("console_backend", [
+    (1, "XENCONSOLED"),
+    (2, "IOEMU"),
+    ])
+
+libxl__device_console = Struct("device_console", [
+    ("backend_domid", libxl_domid),
+    ("devid", integer),
+    ("consback", libxl__console_backend),
+    ("output", string),
+    ])
diff --git a/tools/libxl/libxl_utils.c b/tools/libxl/libxl_utils.c
index cd819c808c..d6cd78d8f2 100644
--- a/tools/libxl/libxl_utils.c
+++ b/tools/libxl/libxl_utils.c
@@ -19,18 +19,6 @@
 
 #include "libxl_internal.h"
 
-struct schedid_name {
-    char *name;
-    int id;
-};
-
-static struct schedid_name schedid_name[] = {
-    { "credit", XEN_SCHEDULER_CREDIT },
-    { "sedf", XEN_SCHEDULER_SEDF },
-    { "credit2", XEN_SCHEDULER_CREDIT2 },
-    { NULL, -1 }
-};
-
 const char *libxl_basename(const char *name)
 {
     const char *filename;
@@ -151,28 +139,6 @@ int libxl_name_to_cpupoolid(libxl_ctx *ctx, const char *name,
     return ret;
 }
 
-int libxl_name_to_schedid(libxl_ctx *ctx, const char *name)
-{
-    int i;
-
-    for (i = 0; schedid_name[i].name != NULL; i++)
-        if (strcmp(name, schedid_name[i].name) == 0)
-            return schedid_name[i].id;
-
-    return ERROR_INVAL;
-}
-
-char *libxl_schedid_to_name(libxl_ctx *ctx, int schedid)
-{
-    int i;
-
-    for (i = 0; schedid_name[i].name != NULL; i++)
-        if (schedid_name[i].id == schedid)
-            return schedid_name[i].name;
-
-    return "unknown";
-}
-
 int libxl_get_stubdom_id(libxl_ctx *ctx, int guest_domid)
 {
     GC_INIT(ctx);
@@ -541,6 +507,29 @@ void libxl_cputopology_list_free(libxl_cputopology *list, int nr)
     free(list);
 }
 
+void libxl_dominfo_list_free(libxl_dominfo *list, int nr)
+{
+    int i;
+    for (i = 0; i < nr; i++)
+        libxl_dominfo_dispose(&list[i]);
+    free(list);
+}
+
+void libxl_vminfo_list_free(libxl_vminfo *list, int nr)
+{
+    int i;
+    for (i = 0; i < nr; i++)
+        libxl_vminfo_dispose(&list[i]);
+    free(list);
+}
+
+int libxl_domid_valid_guest(uint32_t domid)
+{
+    /* returns 1 if the value _could_ be a valid guest domid, 0 otherwise
+     * does not check whether the domain actually exists */
+    return domid > 0 && domid < DOMID_FIRST_RESERVED;
+}
+
 /*
  * Local variables:
  * mode: C
diff --git a/tools/libxl/libxl_utils.h b/tools/libxl/libxl_utils.h
index f3002fd601..a4f5bf2d81 100644
--- a/tools/libxl/libxl_utils.h
+++ b/tools/libxl/libxl_utils.h
@@ -24,8 +24,6 @@ int libxl_name_to_domid(libxl_ctx *ctx, const char *name, uint32_t *domid);
 char *libxl_domid_to_name(libxl_ctx *ctx, uint32_t domid);
 int libxl_name_to_cpupoolid(libxl_ctx *ctx, const char *name, uint32_t *poolid);
 char *libxl_cpupoolid_to_name(libxl_ctx *ctx, uint32_t poolid);
-int libxl_name_to_schedid(libxl_ctx *ctx, const char *name);
-char *libxl_schedid_to_name(libxl_ctx *ctx, int schedid);
 int libxl_get_stubdom_id(libxl_ctx *ctx, int guest_domid);
 int libxl_is_stubdom(libxl_ctx *ctx, uint32_t domid, uint32_t *target_domid);
 int libxl_create_logfile(libxl_ctx *ctx, char *name, char **full_name);
diff --git a/tools/libxl/libxlu_cfg.c b/tools/libxl/libxlu_cfg.c
index e3659c7654..c32cf046c1 100644
--- a/tools/libxl/libxlu_cfg.c
+++ b/tools/libxl/libxlu_cfg.c
@@ -237,6 +237,17 @@ int xlu_cfg_get_long(const XLU_Config *cfg, const char *n,
     return 0;
 }
 
+int xlu_cfg_get_defbool(const XLU_Config *cfg, const char *n, libxl_defbool *b,
+                     int dont_warn)
+{
+    int ret;
+    long l;
+
+    ret = xlu_cfg_get_long(cfg, n, &l, dont_warn);
+    if (ret) return ret;
+    libxl_defbool_set(b, !!l);
+    return 0;
+}
 
 int xlu_cfg_get_list(const XLU_Config *cfg, const char *n,
                      XLU_ConfigList **list_r, int *entries_r, int dont_warn) {
diff --git a/tools/libxl/libxlutil.h b/tools/libxl/libxlutil.h
index edb3264ce6..620b9dbb47 100644
--- a/tools/libxl/libxlutil.h
+++ b/tools/libxl/libxlutil.h
@@ -52,6 +52,8 @@ int xlu_cfg_replace_string(const XLU_Config *cfg, const char *n,
                            char **value_r, int dont_warn);
 int xlu_cfg_get_long(const XLU_Config*, const char *n, long *value_r,
                      int dont_warn);
+int xlu_cfg_get_defbool(const XLU_Config*, const char *n, libxl_defbool *b,
+                     int dont_warn);
 
 int xlu_cfg_get_list(const XLU_Config*, const char *n,
                      XLU_ConfigList **list_r /* may be 0 */,
diff --git a/tools/libxl/xl_cmdimpl.c b/tools/libxl/xl_cmdimpl.c
index d60e22b337..47527440ca 100644
--- a/tools/libxl/xl_cmdimpl.c
+++ b/tools/libxl/xl_cmdimpl.c
@@ -144,7 +144,6 @@ static int qualifier_to_id(const char *p, uint32_t *id_r)
 static int domain_qualifier_to_domid(const char *p, uint32_t *domid_r,
                                      int *was_name_r)
 {
-    libxl_dominfo dominfo;
     int was_name, rc;
 
     was_name = qualifier_to_id(p, domid_r);
@@ -156,7 +155,7 @@ static int domain_qualifier_to_domid(const char *p, uint32_t *domid_r,
         if (rc)
             return rc;
     } else {
-        rc = libxl_domain_info(ctx, &dominfo, *domid_r);
+        rc = libxl_domain_info(ctx, NULL, *domid_r);
         /* error only if domain does not exist */
         if (rc == ERROR_INVAL)
             return rc;
@@ -383,7 +382,7 @@ static void parse_disk_config_multistring(XLU_Config **config,
 {
     int e;
 
-    libxl_device_disk_init(ctx, disk);
+    libxl_device_disk_init(disk);
 
     if (!*config) {
         *config = xlu_cfg_init(stderr, "command line");
@@ -536,8 +535,7 @@ static void parse_config_data(const char *configfile_filename_report,
         exit(1);
     }
 
-    if (libxl_init_create_info(ctx, c_info))
-        exit(1);
+    libxl_domain_create_info_init(c_info);
 
     if (!xlu_cfg_get_string (config, "seclabel", &buf, 0)) {
         e = libxl_flask_context_to_sid(ctx, (char *)buf, strlen(buf),
@@ -557,8 +555,7 @@ static void parse_config_data(const char *configfile_filename_report,
         !strncmp(buf, "hvm", strlen(buf)))
         c_info->type = LIBXL_DOMAIN_TYPE_HVM;
 
-    if (!xlu_cfg_get_long (config, "hap", &l, 0))
-        c_info->hap = l;
+    xlu_cfg_get_defbool(config, "hap", &c_info->hap, 0);
 
     if (xlu_cfg_replace_string (config, "name", &c_info->name, 0)) {
         fprintf(stderr, "Domain name must be specified.\n");
@@ -574,8 +571,7 @@ static void parse_config_data(const char *configfile_filename_report,
         libxl_uuid_generate(&c_info->uuid);
     }
 
-    if (!xlu_cfg_get_long(config, "oos", &l, 0))
-        c_info->oos = l;
+    xlu_cfg_get_defbool(config, "oos", &c_info->oos, 0);
 
     if (!xlu_cfg_get_string (config, "pool", &buf, 0)) {
         c_info->poolid = -1;
@@ -586,8 +582,8 @@ static void parse_config_data(const char *configfile_filename_report,
         exit(1);
     }
 
-    if (libxl_init_build_info(ctx, b_info, c_info))
-        exit(1);
+    libxl_domain_build_info_init(b_info);
+    libxl_domain_build_info_init_type(b_info, c_info->type);
 
     /* the following is the actual config parsing with overriding values in the structures */
     if (!xlu_cfg_get_long (config, "vcpus", &l, 0)) {
@@ -601,6 +597,11 @@ static void parse_config_data(const char *configfile_filename_report,
     if (!xlu_cfg_get_list (config, "cpus", &cpus, 0, 1)) {
         int i, n_cpus = 0;
 
+        if (libxl_cpumap_alloc(ctx, &b_info->cpumap)) {
+            fprintf(stderr, "Unable to allocate cpumap\n");
+            exit(1);
+        }
+
         libxl_cpumap_set_none(&b_info->cpumap);
         while ((buf = xlu_cfg_get_listitem(cpus, n_cpus)) != NULL) {
             i = atoi(buf);
@@ -615,6 +616,11 @@ static void parse_config_data(const char *configfile_filename_report,
     else if (!xlu_cfg_get_string (config, "cpus", &buf, 0)) {
         char *buf2 = strdup(buf);
 
+        if (libxl_cpumap_alloc(ctx, &b_info->cpumap)) {
+            fprintf(stderr, "Unable to allocate cpumap\n");
+            exit(1);
+        }
+
         libxl_cpumap_set_none(&b_info->cpumap);
         if (vcpupin_parse(buf2, &b_info->cpumap))
             exit(1);
@@ -666,8 +672,7 @@ static void parse_config_data(const char *configfile_filename_report,
         : libxl_get_required_shadow_memory(b_info->max_memkb,
                                            b_info->max_vcpus);
 
-    if (!xlu_cfg_get_long (config, "nomigrate", &l, 0))
-        b_info->disable_migrate = l;
+    xlu_cfg_get_defbool(config, "nomigrate", &b_info->disable_migrate, 0);
 
     if (!xlu_cfg_get_long(config, "tsc_mode", &l, 1)) {
         const char *s = libxl_tsc_mode_to_string(l);
@@ -695,7 +700,7 @@ static void parse_config_data(const char *configfile_filename_report,
     if (!xlu_cfg_get_long (config, "videoram", &l, 0))
         b_info->video_memkb = l * 1024;
 
-    switch(c_info->type) {
+    switch(b_info->type) {
     case LIBXL_DOMAIN_TYPE_HVM:
         if (!xlu_cfg_get_string (config, "kernel", &buf, 0))
             fprintf(stderr, "WARNING: ignoring \"kernel\" directive for HVM guest. "
@@ -709,24 +714,16 @@ static void parse_config_data(const char *configfile_filename_report,
                     buf);
                 exit (1);
         }
-        if (!xlu_cfg_get_long (config, "pae", &l, 0))
-            b_info->u.hvm.pae = l;
-        if (!xlu_cfg_get_long (config, "apic", &l, 0))
-            b_info->u.hvm.apic = l;
-        if (!xlu_cfg_get_long (config, "acpi", &l, 0))
-            b_info->u.hvm.acpi = l;
-        if (!xlu_cfg_get_long (config, "acpi_s3", &l, 0))
-            b_info->u.hvm.acpi_s3 = l;
-        if (!xlu_cfg_get_long (config, "acpi_s4", &l, 0))
-            b_info->u.hvm.acpi_s4 = l;
-        if (!xlu_cfg_get_long (config, "nx", &l, 0))
-            b_info->u.hvm.nx = l;
-        if (!xlu_cfg_get_long (config, "viridian", &l, 0))
-            b_info->u.hvm.viridian = l;
-        if (!xlu_cfg_get_long (config, "hpet", &l, 0))
-            b_info->u.hvm.hpet = l;
-        if (!xlu_cfg_get_long (config, "vpt_align", &l, 0))
-            b_info->u.hvm.vpt_align = l;
+
+        xlu_cfg_get_defbool(config, "pae", &b_info->u.hvm.pae, 0);
+        xlu_cfg_get_defbool(config, "apic", &b_info->u.hvm.apic, 0);
+        xlu_cfg_get_defbool(config, "acpi", &b_info->u.hvm.acpi, 0);
+        xlu_cfg_get_defbool(config, "acpi_s3", &b_info->u.hvm.acpi_s3, 0);
+        xlu_cfg_get_defbool(config, "acpi_s4", &b_info->u.hvm.acpi_s4, 0);
+        xlu_cfg_get_defbool(config, "nx", &b_info->u.hvm.nx, 0);
+        xlu_cfg_get_defbool(config, "viridian", &b_info->u.hvm.viridian, 0);
+        xlu_cfg_get_defbool(config, "hpet", &b_info->u.hvm.hpet, 0);
+        xlu_cfg_get_defbool(config, "vpt_align", &b_info->u.hvm.vpt_align, 0);
 
         if (!xlu_cfg_get_long(config, "timer_mode", &l, 1)) {
             const char *s = libxl_timer_mode_to_string(l);
@@ -751,8 +748,7 @@ static void parse_config_data(const char *configfile_filename_report,
             }
         }
 
-        if (!xlu_cfg_get_long (config, "nestedhvm", &l, 0))
-            b_info->u.hvm.nested_hvm = l;
+        xlu_cfg_get_defbool(config, "nestedhvm", &b_info->u.hvm.nested_hvm, 0);
         break;
     case LIBXL_DOMAIN_TYPE_PV:
     {
@@ -837,7 +833,7 @@ static void parse_config_data(const char *configfile_filename_report,
 
             d_config->vifs = (libxl_device_nic *) realloc(d_config->vifs, sizeof (libxl_device_nic) * (d_config->num_vifs+1));
             nic = d_config->vifs + d_config->num_vifs;
-            CHK_ERRNO( libxl_device_nic_init(ctx, nic) );
+            libxl_device_nic_init(nic);
             nic->devid = d_config->num_vifs;
 
             if (default_vifscript) {
@@ -933,12 +929,12 @@ skip:
 
             d_config->vfbs = (libxl_device_vfb *) realloc(d_config->vfbs, sizeof(libxl_device_vfb) * (d_config->num_vfbs + 1));
             vfb = d_config->vfbs + d_config->num_vfbs;
-            libxl_device_vfb_init(ctx, vfb);
+            libxl_device_vfb_init(vfb);
             vfb->devid = d_config->num_vfbs;
 
             d_config->vkbs = (libxl_device_vkb *) realloc(d_config->vkbs, sizeof(libxl_device_vkb) * (d_config->num_vkbs + 1));
             vkb = d_config->vkbs + d_config->num_vkbs;
-            libxl_device_vkb_init(ctx, vkb);
+            libxl_device_vkb_init(vkb);
             vkb->devid = d_config->num_vkbs;
 
             p = strtok(buf2, ",");
@@ -951,7 +947,7 @@ skip:
                     break;
                 *p2 = '\0';
                 if (!strcmp(p, "vnc")) {
-                    vfb->vnc.enable = atoi(p2 + 1);
+                    libxl_defbool_set(&vfb->vnc.enable, atoi(p2 + 1));
                 } else if (!strcmp(p, "vnclisten")) {
                     free(vfb->vnc.listen);
                     vfb->vnc.listen = strdup(p2 + 1);
@@ -961,14 +957,14 @@ skip:
                 } else if (!strcmp(p, "vncdisplay")) {
                     vfb->vnc.display = atoi(p2 + 1);
                 } else if (!strcmp(p, "vncunused")) {
-                    vfb->vnc.findunused = atoi(p2 + 1);
+                    libxl_defbool_set(&vfb->vnc.findunused, atoi(p2 + 1));
                 } else if (!strcmp(p, "keymap")) {
                     free(vfb->keymap);
                     vfb->keymap = strdup(p2 + 1);
                 } else if (!strcmp(p, "sdl")) {
-                    vfb->sdl.enable = atoi(p2 + 1);
+                    libxl_defbool_set(&vfb->sdl.enable, atoi(p2 + 1));
                 } else if (!strcmp(p, "opengl")) {
-                    vfb->sdl.opengl = atoi(p2 + 1);
+                    libxl_defbool_set(&vfb->sdl.opengl, atoi(p2 + 1));
                 } else if (!strcmp(p, "display")) {
                     free(vfb->sdl.display);
                     vfb->sdl.display = strdup(p2 + 1);
@@ -992,19 +988,10 @@ skip_vfb:
 
     /* To be reworked (automatically enabled) once the auto ballooning
      * after guest starts is done (with PCI devices passed in). */
-    if (!xlu_cfg_get_long (config, "e820_host", &l, 0)) {
-        switch (c_info->type) {
-        case LIBXL_DOMAIN_TYPE_HVM:
-            fprintf(stderr, "Can't do e820_host in HVM mode!");
-            break;
-        case LIBXL_DOMAIN_TYPE_PV:
-            if (l)
-                b_info->u.pv.e820_host = true;
-            break;
-        default:
-            abort();
-        }
+    if (c_info->type == LIBXL_DOMAIN_TYPE_PV) {
+        xlu_cfg_get_defbool(config, "e820_host", &b_info->u.pv.e820_host, 0);
     }
+
     if (!xlu_cfg_get_list (config, "pci", &pcis, 0, 0)) {
         int i;
         d_config->num_pcidevs = 0;
@@ -1014,7 +1001,7 @@ skip_vfb:
 
             d_config->pcidevs = (libxl_device_pci *) realloc(d_config->pcidevs, sizeof (libxl_device_pci) * (d_config->num_pcidevs + 1));
             pcidev = d_config->pcidevs + d_config->num_pcidevs;
-            memset(pcidev, 0x00, sizeof(libxl_device_pci));
+            libxl_device_pci_init(pcidev);
 
             pcidev->msitranslate = pci_msitranslate;
             pcidev->power_mgmt = pci_power_mgmt;
@@ -1022,7 +1009,7 @@ skip_vfb:
                 d_config->num_pcidevs++;
         }
         if (d_config->num_pcidevs && c_info->type == LIBXL_DOMAIN_TYPE_PV)
-            b_info->u.pv.e820_host = true;
+            libxl_defbool_set(&b_info->u.pv.e820_host, true);
     }
 
     switch (xlu_cfg_get_list(config, "cpuid", &cpuids, 0, 1)) {
@@ -1139,8 +1126,8 @@ skip_vfb:
         }
     } else if (b_info->device_model)
         fprintf(stderr, "WARNING: device model override given without specific DM version\n");
-    if (!xlu_cfg_get_long (config, "device_model_stubdomain_override", &l, 0))
-        b_info->device_model_stubdomain = l;
+    xlu_cfg_get_defbool (config, "device_model_stubdomain_override",
+                         &b_info->device_model_stubdomain, 0);
 
     if (!xlu_cfg_get_string (config, "device_model_stubdomain_seclabel",
                              &buf, 0)) {
@@ -1177,49 +1164,43 @@ skip_vfb:
 #undef parse_extra_args
 
     if (c_info->type == LIBXL_DOMAIN_TYPE_HVM) {
-        if (!xlu_cfg_get_long (config, "stdvga", &l, 0))
-            b_info->u.hvm.stdvga = l;
-        if (!xlu_cfg_get_long (config, "vnc", &l, 0))
-            b_info->u.hvm.vnc.enable = l;
-        xlu_cfg_replace_string (config, "vnclisten", &b_info->u.hvm.vnc.listen, 0);
-        xlu_cfg_replace_string (config, "vncpasswd", &b_info->u.hvm.vnc.passwd, 0);
+        xlu_cfg_get_defbool(config, "stdvga", &b_info->u.hvm.stdvga, 0);
+        xlu_cfg_get_defbool(config, "vnc", &b_info->u.hvm.vnc.enable, 0);
+        xlu_cfg_replace_string (config, "vnclisten",
+                                &b_info->u.hvm.vnc.listen, 0);
+        xlu_cfg_replace_string (config, "vncpasswd",
+                                &b_info->u.hvm.vnc.passwd, 0);
         if (!xlu_cfg_get_long (config, "vncdisplay", &l, 0))
             b_info->u.hvm.vnc.display = l;
-        if (!xlu_cfg_get_long (config, "vncunused", &l, 0))
-            b_info->u.hvm.vnc.findunused = l;
+        xlu_cfg_get_defbool(config, "vncunused",
+                            &b_info->u.hvm.vnc.findunused, 0);
         xlu_cfg_replace_string (config, "keymap", &b_info->u.hvm.keymap, 0);
-        if (!xlu_cfg_get_long (config, "sdl", &l, 0))
-            b_info->u.hvm.sdl.enable = l;
-        if (!xlu_cfg_get_long (config, "opengl", &l, 0))
-            b_info->u.hvm.sdl.opengl = l;
-        if (!xlu_cfg_get_long (config, "spice", &l, 0))
-            b_info->u.hvm.spice.enable = l;
+        xlu_cfg_get_defbool(config, "sdl", &b_info->u.hvm.sdl.enable, 0);
+        xlu_cfg_get_defbool(config, "opengl", &b_info->u.hvm.sdl.opengl, 0);
+        xlu_cfg_get_defbool (config, "spice", &b_info->u.hvm.spice.enable, 0);
         if (!xlu_cfg_get_long (config, "spiceport", &l, 0))
             b_info->u.hvm.spice.port = l;
         if (!xlu_cfg_get_long (config, "spicetls_port", &l, 0))
             b_info->u.hvm.spice.tls_port = l;
         xlu_cfg_replace_string (config, "spicehost",
                                 &b_info->u.hvm.spice.host, 0);
-        if (!xlu_cfg_get_long (config, "spicedisable_ticketing", &l, 0))
-            b_info->u.hvm.spice.disable_ticketing = l;
+        xlu_cfg_get_defbool(config, "spicedisable_ticketing",
+                            &b_info->u.hvm.spice.disable_ticketing, 0);
         xlu_cfg_replace_string (config, "spicepasswd",
                                 &b_info->u.hvm.spice.passwd, 0);
-        if (!xlu_cfg_get_long (config, "spiceagent_mouse", &l, 0))
-            b_info->u.hvm.spice.agent_mouse = l;
-        else
-            b_info->u.hvm.spice.agent_mouse = 1;
-        if (!xlu_cfg_get_long (config, "nographic", &l, 0))
-            b_info->u.hvm.nographic = l;
-        if (!xlu_cfg_get_long (config, "gfx_passthru", &l, 0))
-            b_info->u.hvm.gfx_passthru = l;
+        xlu_cfg_get_defbool(config, "spiceagent_mouse",
+                            &b_info->u.hvm.spice.agent_mouse, 0);
+        xlu_cfg_get_defbool(config, "nographic", &b_info->u.hvm.nographic, 0);
+        xlu_cfg_get_defbool(config, "gfx_passthru", 
+                            &b_info->u.hvm.gfx_passthru, 0);
         xlu_cfg_replace_string (config, "serial", &b_info->u.hvm.serial, 0);
         xlu_cfg_replace_string (config, "boot", &b_info->u.hvm.boot, 0);
-        if (!xlu_cfg_get_long (config, "usb", &l, 0))
-            b_info->u.hvm.usb = l;
-        xlu_cfg_replace_string (config, "usbdevice", &b_info->u.hvm.usbdevice, 0);
+        xlu_cfg_get_defbool(config, "usb", &b_info->u.hvm.usb, 0);
+        xlu_cfg_replace_string (config, "usbdevice",
+                                &b_info->u.hvm.usbdevice, 0);
         xlu_cfg_replace_string (config, "soundhw", &b_info->u.hvm.soundhw, 0);
-        if (!xlu_cfg_get_long (config, "xen_platform_pci", &l, 0))
-            b_info->u.hvm.xen_platform_pci = l;
+        xlu_cfg_get_defbool(config, "xen_platform_pci",
+                            &b_info->u.hvm.xen_platform_pci, 0);
     }
 
     xlu_cfg_destroy(config);
@@ -1235,19 +1216,19 @@ static int handle_domain_death(libxl_ctx *ctx, uint32_t domid,
     libxl_action_on_shutdown action;
 
     switch (event->u.domain_shutdown.shutdown_reason) {
-    case SHUTDOWN_poweroff:
+    case LIBXL_SHUTDOWN_REASON_POWEROFF:
         action = d_config->on_poweroff;
         break;
-    case SHUTDOWN_reboot:
+    case LIBXL_SHUTDOWN_REASON_REBOOT:
         action = d_config->on_reboot;
         break;
-    case SHUTDOWN_suspend:
+    case LIBXL_SHUTDOWN_REASON_SUSPEND:
         LOG("Domain has suspended.");
         return 0;
-    case SHUTDOWN_crash:
+    case LIBXL_SHUTDOWN_REASON_CRASH:
         action = d_config->on_crash;
         break;
-    case SHUTDOWN_watchdog:
+    case LIBXL_SHUTDOWN_REASON_WATCHDOG:
         action = d_config->on_watchdog;
         break;
     default:
@@ -1371,7 +1352,7 @@ struct domain_create {
     const char *restore_file;
     int migrate_fd; /* -1 means none */
     char **migration_domname_r; /* from malloc */
-    int no_incr_generationid;
+    int incr_generationid;
 };
 
 static int freemem(libxl_domain_build_info *b_info)
@@ -1622,8 +1603,8 @@ static int create_domain(struct domain_create *dom_info)
     }
 
     if (d_config.c_info.type == LIBXL_DOMAIN_TYPE_HVM)
-        d_config.b_info.u.hvm.no_incr_generationid =
-            dom_info->no_incr_generationid;
+        libxl_defbool_set(&d_config.b_info.u.hvm.incr_generationid,
+                          dom_info->incr_generationid);
 
     if (debug || dom_info->dryrun)
         printf_info(default_output_format, -1, &d_config);
@@ -2505,7 +2486,7 @@ static void list_vm(void)
             info[i].domid, domname);
         free(domname);
     }
-    free(info);
+    libxl_vminfo_list_free(info, nb_vm);
 }
 
 static void save_domain_core_begin(const char *domain_spec,
@@ -2898,7 +2879,7 @@ static void migrate_receive(int debug, int daemonize, int monitor)
     dom_info.restore_file = "incoming migration stream";
     dom_info.migrate_fd = 0; /* stdin */
     dom_info.migration_domname_r = &migration_domname;
-    dom_info.no_incr_generationid = 1;
+    dom_info.incr_generationid = 0;
 
     rc = create_domain(&dom_info);
     if (rc < 0) {
@@ -3023,6 +3004,7 @@ int main_restore(int argc, char **argv)
     dom_info.restore_file = checkpoint_file;
     dom_info.migrate_fd = -1;
     dom_info.console_autoconnect = console_autoconnect;
+    dom_info.incr_generationid = 1;
 
     rc = create_domain(&dom_info);
     if (rc < 0)
@@ -3302,7 +3284,10 @@ int main_list(int argc, char **argv)
     else
         list_domains(verbose, context, info, nb_domain);
 
-    free(info_free);
+    if (info_free)
+        libxl_dominfo_list_free(info, nb_domain);
+    else
+        libxl_dominfo_dispose(info);
 
     return 0;
 }
@@ -3405,6 +3390,7 @@ int main_create(int argc, char **argv)
     dom_info.extra_config = extra_config;
     dom_info.migrate_fd = -1;
     dom_info.console_autoconnect = console_autoconnect;
+    dom_info.incr_generationid = 0;
 
     rc = create_domain(&dom_info);
     if (rc < 0)
@@ -3565,8 +3551,7 @@ static void vcpulist(int argc, char **argv)
         for (i = 0; i<nb_domain; i++)
             print_domain_vcpuinfo(dominfo[i].domid, physinfo.nr_cpus);
 
-        free(dominfo);
-
+        libxl_dominfo_list_free(dominfo, nb_domain);
     } else {
         for (; argc > 0; ++argv, --argc) {
             if (domain_qualifier_to_domid(*argv, &domid, 0) < 0) {
@@ -3578,7 +3563,7 @@ static void vcpulist(int argc, char **argv)
         }
     }
   vcpulist_out:
-    ;
+    libxl_physinfo_dispose(&physinfo);
 }
 
 int main_vcpulist(int argc, char **argv)
@@ -3693,15 +3678,15 @@ int main_vcpuset(int argc, char **argv)
 static void output_xeninfo(void)
 {
     const libxl_version_info *info;
-    int sched_id;
+    libxl_scheduler sched;
 
     if (!(info = libxl_get_version_info(ctx))) {
         fprintf(stderr, "libxl_get_version_info failed.\n");
         return;
     }
 
-    if ((sched_id = libxl_get_sched_id(ctx)) < 0) {
-        fprintf(stderr, "get_sched_id sysctl failed.\n");
+    if ((sched = libxl_get_scheduler(ctx)) < 0) {
+        fprintf(stderr, "get_scheduler sysctl failed.\n");
         return;
     }
 
@@ -3709,7 +3694,7 @@ static void output_xeninfo(void)
     printf("xen_minor              : %d\n", info->xen_version_minor);
     printf("xen_extra              : %s\n", info->xen_version_extra);
     printf("xen_caps               : %s\n", info->capabilities);
-    printf("xen_scheduler          : %s\n", libxl_schedid_to_name(ctx, sched_id));
+    printf("xen_scheduler          : %s\n", libxl_scheduler_to_string(sched));
     printf("xen_pagesize           : %u\n", info->pagesize);
     printf("platform_params        : virt_start=0x%"PRIx64"\n", info->virt_start);
     printf("xen_changeset          : %s\n", info->changeset);
@@ -3757,9 +3742,9 @@ static void output_physinfo(void)
     for (i = 0; i < 8; i++)
         printf("%08x%c", info.hw_cap[i], i < 7 ? ':' : '\n');
     printf("virt_caps              :");
-    if (info.phys_cap & XEN_SYSCTL_PHYSCAP_hvm)
+    if (info.cap_hvm)
         printf(" hvm");
-    if (info.phys_cap & XEN_SYSCTL_PHYSCAP_hvm_directio)
+    if (info.cap_hvm_directio)
         printf(" hvm_directio");
     printf("\n");
     vinfo = libxl_get_version_info(ctx);
@@ -3778,6 +3763,7 @@ static void output_physinfo(void)
         free(cpumap.map);
     }
 
+    libxl_physinfo_dispose(&info);
     return;
 }
 
@@ -3912,7 +3898,9 @@ int main_sharing(int argc, char **argv)
     sharing(info, nb_domain);
 
     if (info_free)
-        free(info_free);
+        libxl_dominfo_list_free(info_free, nb_domain);
+    else
+        libxl_dominfo_dispose(info);
 
     return 0;
 }
@@ -3934,6 +3922,7 @@ static int sched_credit_domain_set(
 {
     int rc;
 
+    
     rc = libxl_sched_credit_domain_set(ctx, domid, scinfo);
     if (rc)
         fprintf(stderr, "libxl_sched_credit_domain_set failed.\n");
@@ -3962,6 +3951,7 @@ static int sched_credit_domain_output(
         scinfo.weight,
         scinfo.cap);
     free(domname);
+    libxl_sched_credit_domain_dispose(&scinfo);
     return 0;
 }
 
@@ -4009,6 +3999,7 @@ static int sched_credit2_domain_output(
         domid,
         scinfo.weight);
     free(domname);
+    libxl_sched_credit2_domain_dispose(&scinfo);
     return 0;
 }
 
@@ -4032,7 +4023,6 @@ static int sched_sedf_domain_set(
     rc = libxl_sched_sedf_domain_set(ctx, domid, scinfo);
     if (rc)
         fprintf(stderr, "libxl_sched_sedf_domain_set failed.\n");
-
     return rc;
 }
 
@@ -4061,11 +4051,12 @@ static int sched_sedf_domain_output(
         scinfo.extratime,
         scinfo.weight);
     free(domname);
+    libxl_sched_sedf_domain_dispose(&scinfo);
     return 0;
 }
 
 static int sched_domain_output(
-    uint32_t sched, int (*output)(int), const char *cpupool)
+    libxl_scheduler sched, int (*output)(int), const char *cpupool)
 {
     libxl_dominfo *info;
     libxl_cpupoolinfo *poolinfo = NULL;
@@ -4094,7 +4085,7 @@ static int sched_domain_output(
     }
 
     for (p = 0; !rc && (p < n_pools); p++) {
-        if ((poolinfo[p].sched_id != sched) ||
+        if ((poolinfo[p].sched != sched) ||
             (cpupool && (poolid != poolinfo[p].poolid)))
             continue;
 
@@ -4175,7 +4166,7 @@ int main_sched_credit(int argc, char **argv)
     }
 
     if (!dom) { /* list all domain's credit scheduler info */
-        return -sched_domain_output(XEN_SCHEDULER_CREDIT,
+        return -sched_domain_output(LIBXL_SCHEDULER_CREDIT,
                                     sched_credit_domain_output, cpupool);
     } else {
         find_domain(dom);
@@ -4193,6 +4184,7 @@ int main_sched_credit(int argc, char **argv)
             if (opt_c)
                 scinfo.cap = cap;
             rc = sched_credit_domain_set(domid, &scinfo);
+            libxl_sched_credit_domain_dispose(&scinfo);
             if (rc)
                 return -rc;
         }
@@ -4251,7 +4243,7 @@ int main_sched_credit2(int argc, char **argv)
     }
 
     if (!dom) { /* list all domain's credit scheduler info */
-        return -sched_domain_output(XEN_SCHEDULER_CREDIT2,
+        return -sched_domain_output(LIBXL_SCHEDULER_CREDIT2,
                                     sched_credit2_domain_output, cpupool);
     } else {
         find_domain(dom);
@@ -4267,6 +4259,7 @@ int main_sched_credit2(int argc, char **argv)
             if (opt_w)
                 scinfo.weight = weight;
             rc = sched_credit2_domain_set(domid, &scinfo);
+            libxl_sched_credit2_domain_dispose(&scinfo);
             if (rc)
                 return -rc;
         }
@@ -4353,7 +4346,7 @@ int main_sched_sedf(int argc, char **argv)
     }
 
     if (!dom) { /* list all domain's credit scheduler info */
-        return -sched_domain_output(XEN_SCHEDULER_SEDF,
+        return -sched_domain_output(LIBXL_SCHEDULER_SEDF,
                                     sched_sedf_domain_output, cpupool);
     } else {
         find_domain(dom);
@@ -4385,6 +4378,7 @@ int main_sched_sedf(int argc, char **argv)
                 scinfo.slice = 0;
             }
             rc = sched_sedf_domain_set(domid, &scinfo);
+            libxl_sched_sedf_domain_dispose(&scinfo);
             if (rc)
                 return -rc;
         }
@@ -4602,7 +4596,7 @@ int main_networkattach(int argc, char **argv)
         fprintf(stderr, "%s is an invalid domain identifier\n", argv[optind]);
         return 1;
     }
-    libxl_device_nic_init(ctx, &nic);
+    libxl_device_nic_init(&nic);
     for (argv += optind+1, argc -= optind+1; argc > 0; ++argv, --argc) {
         if (MATCH_OPTION("type", *argv, oparg)) {
             if (!strcmp("vif", oparg)) {
@@ -4968,6 +4962,7 @@ static void print_uptime(int short_mode, uint32_t doms[], int nb_doms)
         info = libxl_list_vm(ctx, &nb_vm);
         for (i = 0; i < nb_vm; i++)
             print_domU_uptime(info[i].domid, short_mode, now);
+        libxl_vminfo_list_free(info, nb_vm);
     } else {
         for (i = 0; i < nb_doms; i++) {
             if (doms[i] == 0)
@@ -5292,9 +5287,8 @@ int main_cpupoolcreate(int argc, char **argv)
     XLU_Config *config;
     const char *buf;
     const char *name;
-    const char *sched;
     uint32_t poolid;
-    int schedid = -1;
+    libxl_scheduler sched = 0;
     XLU_ConfigList *cpus;
     XLU_ConfigList *nodes;
     int n_cpus, n_nodes, i, n;
@@ -5389,17 +5383,16 @@ int main_cpupoolcreate(int argc, char **argv)
     }
 
     if (!xlu_cfg_get_string (config, "sched", &buf, 0)) {
-        if ((schedid = libxl_name_to_schedid(ctx, buf)) < 0) {
+        if ((libxl_scheduler_from_string(buf, &sched)) < 0) {
             fprintf(stderr, "Unknown scheduler\n");
             return -ERROR_FAIL;
         }
     } else {
-        if ((schedid = libxl_get_sched_id(ctx)) < 0) {
-            fprintf(stderr, "get_sched_id sysctl failed.\n");
+        if ((sched = libxl_get_scheduler(ctx)) < 0) {
+            fprintf(stderr, "get_scheduler sysctl failed.\n");
             return -ERROR_FAIL;
         }
     }
-    sched = libxl_schedid_to_name(ctx, schedid);
 
     if (libxl_get_freecpus(ctx, &freemap)) {
         fprintf(stderr, "libxl_get_freecpus failed\n");
@@ -5467,14 +5460,14 @@ int main_cpupoolcreate(int argc, char **argv)
 
     printf("Using config file \"%s\"\n", filename);
     printf("cpupool name:   %s\n", name);
-    printf("scheduler:      %s\n", sched);
+    printf("scheduler:      %s\n", libxl_scheduler_to_string(sched));
     printf("number of cpus: %d\n", n_cpus);
 
     if (dryrun_only)
         return 0;
 
     poolid = 0;
-    if (libxl_cpupool_create(ctx, name, schedid, cpumap, &uuid, &poolid)) {
+    if (libxl_cpupool_create(ctx, name, sched, cpumap, &uuid, &poolid)) {
         fprintf(stderr, "error on creating cpupool\n");
         return -ERROR_FAIL;
     }
@@ -5559,7 +5552,7 @@ int main_cpupoollist(int argc, char **argv)
                     }
                 if (!opt_cpus) {
                     printf("%3d %9s       y       %4d", n,
-                           libxl_schedid_to_name(ctx, poolinfo[p].sched_id),
+                           libxl_scheduler_to_string(poolinfo[p].sched),
                            poolinfo[p].n_dom);
                 }
                 printf("\n");
@@ -5744,7 +5737,7 @@ int main_cpupoolnumasplit(int argc, char **argv)
     int c;
     int n;
     uint32_t poolid;
-    int schedid;
+    libxl_scheduler sched;
     int n_pools;
     int node;
     int n_cpus;
@@ -5765,7 +5758,7 @@ int main_cpupoolnumasplit(int argc, char **argv)
         return -ERROR_NOMEM;
     }
     poolid = poolinfo[0].poolid;
-    schedid = poolinfo[0].sched_id;
+    sched = poolinfo[0].sched;
     for (p = 0; p < n_pools; p++) {
         libxl_cpupoolinfo_dispose(poolinfo + p);
     }
@@ -5845,7 +5838,7 @@ int main_cpupoolnumasplit(int argc, char **argv)
         snprintf(name, 15, "Pool-node%d", node);
         libxl_uuid_generate(&uuid);
         poolid = 0;
-        ret = -libxl_cpupool_create(ctx, name, schedid, cpumap, &uuid, &poolid);
+        ret = -libxl_cpupool_create(ctx, name, sched, cpumap, &uuid, &poolid);
         if (ret) {
             fprintf(stderr, "error on creating cpupool\n");
             goto out;
diff --git a/tools/libxl/xl_sxp.c b/tools/libxl/xl_sxp.c
index 25ca0bdd11..c68b6df698 100644
--- a/tools/libxl/xl_sxp.c
+++ b/tools/libxl/xl_sxp.c
@@ -21,6 +21,7 @@
 #include "libxl_osdeps.h"
 
 #include <stdlib.h>
+#include <inttypes.h>
 
 #include "libxl.h"
 #include "libxl_utils.h"
@@ -40,8 +41,8 @@ void printf_info_sexp(int domid, libxl_domain_config *d_config)
     printf("(domain\n\t(domid %d)\n", domid);
     printf("\t(create_info)\n");
     printf("\t(hvm %d)\n", c_info->type == LIBXL_DOMAIN_TYPE_HVM);
-    printf("\t(hap %d)\n", c_info->hap);
-    printf("\t(oos %d)\n", c_info->oos);
+    printf("\t(hap %s)\n", libxl_defbool_to_string(c_info->hap));
+    printf("\t(oos %s)\n", libxl_defbool_to_string(c_info->oos));
     printf("\t(ssidref %d)\n", c_info->ssidref);
     printf("\t(name %s)\n", c_info->name);
 
@@ -68,9 +69,10 @@ void printf_info_sexp(int domid, libxl_domain_config *d_config)
     printf("\t(build_info)\n");
     printf("\t(max_vcpus %d)\n", b_info->max_vcpus);
     printf("\t(tsc_mode %s)\n", libxl_tsc_mode_to_string(b_info->tsc_mode));
-    printf("\t(max_memkb %d)\n", b_info->max_memkb);
-    printf("\t(target_memkb %d)\n", b_info->target_memkb);
-    printf("\t(nomigrate %d)\n", b_info->disable_migrate);
+    printf("\t(max_memkb %"PRId64")\n", b_info->max_memkb);
+    printf("\t(target_memkb %"PRId64")\n", b_info->target_memkb);
+    printf("\t(nomigrate %s)\n",
+           libxl_defbool_to_string(b_info->disable_migrate));
 
     if (c_info->type == LIBXL_DOMAIN_TYPE_PV && b_info->u.pv.bootloader) {
         int i;
@@ -88,43 +90,57 @@ void printf_info_sexp(int domid, libxl_domain_config *d_config)
     case LIBXL_DOMAIN_TYPE_HVM:
         printf("\t\t(hvm\n");
         printf("\t\t\t(firmware %s)\n", b_info->u.hvm.firmware);
-        printf("\t\t\t(video_memkb %d)\n", b_info->video_memkb);
-        printf("\t\t\t(shadow_memkb %d)\n", b_info->shadow_memkb);
-        printf("\t\t\t(pae %d)\n", b_info->u.hvm.pae);
-        printf("\t\t\t(apic %d)\n", b_info->u.hvm.apic);
-        printf("\t\t\t(acpi %d)\n", b_info->u.hvm.acpi);
-        printf("\t\t\t(nx %d)\n", b_info->u.hvm.nx);
-        printf("\t\t\t(viridian %d)\n", b_info->u.hvm.viridian);
-        printf("\t\t\t(hpet %d)\n", b_info->u.hvm.hpet);
-        printf("\t\t\t(vpt_align %d)\n", b_info->u.hvm.vpt_align);
+        printf("\t\t\t(video_memkb %"PRId64")\n", b_info->video_memkb);
+        printf("\t\t\t(shadow_memkb %"PRId64")\n", b_info->shadow_memkb);
+        printf("\t\t\t(pae %s)\n", libxl_defbool_to_string(b_info->u.hvm.pae));
+        printf("\t\t\t(apic %s)\n",
+               libxl_defbool_to_string(b_info->u.hvm.apic));
+        printf("\t\t\t(acpi %s)\n",
+               libxl_defbool_to_string(b_info->u.hvm.acpi));
+        printf("\t\t\t(nx %s)\n", libxl_defbool_to_string(b_info->u.hvm.nx));
+        printf("\t\t\t(viridian %s)\n",
+               libxl_defbool_to_string(b_info->u.hvm.viridian));
+        printf("\t\t\t(hpet %s)\n",
+               libxl_defbool_to_string(b_info->u.hvm.hpet));
+        printf("\t\t\t(vpt_align %s)\n",
+               libxl_defbool_to_string(b_info->u.hvm.vpt_align));
         printf("\t\t\t(timer_mode %s)\n",
                libxl_timer_mode_to_string(b_info->u.hvm.timer_mode));
-        printf("\t\t\t(nestedhvm %d)\n", b_info->u.hvm.nested_hvm);
-        printf("\t\t\t(no_incr_generationid %d)\n",
-                    b_info->u.hvm.no_incr_generationid);
-
-        printf("\t\t\t(stdvga %d)\n", b_info->u.hvm.stdvga);
-        printf("\t\t\t(vnc %d)\n", b_info->u.hvm.vnc.enable);
+        printf("\t\t\t(nestedhvm %s)\n",
+               libxl_defbool_to_string(b_info->u.hvm.nested_hvm));
+        printf("\t\t\t(no_incr_generationid %s)\n",
+               libxl_defbool_to_string(b_info->u.hvm.incr_generationid));
+        printf("\t\t\t(stdvga %s)\n",
+               libxl_defbool_to_string(b_info->u.hvm.stdvga));
+        printf("\t\t\t(vnc %s)\n",
+               libxl_defbool_to_string(b_info->u.hvm.vnc.enable));
         printf("\t\t\t(vnclisten %s)\n", b_info->u.hvm.vnc.listen);
         printf("\t\t\t(vncdisplay %d)\n", b_info->u.hvm.vnc.display);
-        printf("\t\t\t(vncunused %d)\n", b_info->u.hvm.vnc.findunused);
+        printf("\t\t\t(vncunused %s)\n",
+               libxl_defbool_to_string(b_info->u.hvm.vnc.findunused));
         printf("\t\t\t(keymap %s)\n", b_info->u.hvm.keymap);
-        printf("\t\t\t(sdl %d)\n", b_info->u.hvm.sdl.enable);
-        printf("\t\t\t(opengl %d)\n", b_info->u.hvm.sdl.opengl);
-        printf("\t\t\t(nographic %d)\n", b_info->u.hvm.nographic);
-        printf("\t\t\t(spice %d)\n", b_info->u.hvm.spice.enable);
+        printf("\t\t\t(sdl %s)\n",
+               libxl_defbool_to_string(b_info->u.hvm.sdl.enable));
+        printf("\t\t\t(opengl %s)\n",
+               libxl_defbool_to_string(b_info->u.hvm.sdl.opengl));
+        printf("\t\t\t(nographic %s)\n",
+               libxl_defbool_to_string(b_info->u.hvm.nographic));
+        printf("\t\t\t(spice %s)\n",
+               libxl_defbool_to_string(b_info->u.hvm.spice.enable));
         printf("\t\t\t(spiceport %d)\n", b_info->u.hvm.spice.port);
         printf("\t\t\t(spicetls_port %d)\n", b_info->u.hvm.spice.tls_port);
         printf("\t\t\t(spicehost %s)\n", b_info->u.hvm.spice.host);
-        printf("\t\t\t(spicedisable_ticketing %d)\n",
-                    b_info->u.hvm.spice.disable_ticketing);
-        printf("\t\t\t(spiceagent_mouse %d)\n", b_info->u.hvm.spice.agent_mouse);
+        printf("\t\t\t(spicedisable_ticketing %s)\n",
+               libxl_defbool_to_string(b_info->u.hvm.spice.disable_ticketing));
+        printf("\t\t\t(spiceagent_mouse %s)\n",
+               libxl_defbool_to_string(b_info->u.hvm.spice.agent_mouse));
 
         printf("\t\t\t(device_model %s)\n", b_info->device_model ? : "default");
-        printf("\t\t\t(gfx_passthru %d)\n", b_info->u.hvm.gfx_passthru);
+        printf("\t\t\t(gfx_passthru %s)\n",
+               libxl_defbool_to_string(b_info->u.hvm.gfx_passthru));
         printf("\t\t\t(serial %s)\n", b_info->u.hvm.serial);
         printf("\t\t\t(boot %s)\n", b_info->u.hvm.boot);
-        printf("\t\t\t(usb %d)\n", b_info->u.hvm.usb);
+        printf("\t\t\t(usb %s)\n", libxl_defbool_to_string(b_info->u.hvm.usb));
         printf("\t\t\t(usbdevice %s)\n", b_info->u.hvm.usbdevice);
         printf("\t\t)\n");
         break;
@@ -133,7 +149,8 @@ void printf_info_sexp(int domid, libxl_domain_config *d_config)
         printf("\t\t\t(kernel %s)\n", b_info->u.pv.kernel.path);
         printf("\t\t\t(cmdline %s)\n", b_info->u.pv.cmdline);
         printf("\t\t\t(ramdisk %s)\n", b_info->u.pv.ramdisk.path);
-        printf("\t\t\t(e820_host %d)\n", b_info->u.pv.e820_host);
+        printf("\t\t\t(e820_host %s)\n",
+               libxl_defbool_to_string(b_info->u.pv.e820_host));
         printf("\t\t)\n");
         break;
     default:
@@ -195,13 +212,17 @@ void printf_info_sexp(int domid, libxl_domain_config *d_config)
         printf("\t\t\t(backend_domid %d)\n", d_config->vfbs[i].backend_domid);
         printf("\t\t\t(frontend_domid %d)\n", domid);
         printf("\t\t\t(devid %d)\n", d_config->vfbs[i].devid);
-        printf("\t\t\t(vnc %d)\n", d_config->vfbs[i].vnc.enable);
+        printf("\t\t\t(vnc %s)\n",
+               libxl_defbool_to_string(d_config->vfbs[i].vnc.enable));
         printf("\t\t\t(vnclisten %s)\n", d_config->vfbs[i].vnc.listen);
         printf("\t\t\t(vncdisplay %d)\n", d_config->vfbs[i].vnc.display);
-        printf("\t\t\t(vncunused %d)\n", d_config->vfbs[i].vnc.findunused);
+        printf("\t\t\t(vncunused %s)\n",
+               libxl_defbool_to_string(d_config->vfbs[i].vnc.findunused));
         printf("\t\t\t(keymap %s)\n", d_config->vfbs[i].keymap);
-        printf("\t\t\t(sdl %d)\n", d_config->vfbs[i].sdl.enable);
-        printf("\t\t\t(opengl %d)\n", d_config->vfbs[i].sdl.opengl);
+        printf("\t\t\t(sdl %s)\n",
+               libxl_defbool_to_string(d_config->vfbs[i].sdl.enable));
+        printf("\t\t\t(opengl %s)\n",
+               libxl_defbool_to_string(d_config->vfbs[i].sdl.opengl));
         printf("\t\t\t(display %s)\n", d_config->vfbs[i].sdl.display);
         printf("\t\t\t(xauthority %s)\n", d_config->vfbs[i].sdl.xauthority);
         printf("\t\t)\n");
diff --git a/tools/ocaml/libs/xl/genwrap.py b/tools/ocaml/libs/xl/genwrap.py
index 22cca80bcb..384ec5b4ea 100644
--- a/tools/ocaml/libs/xl/genwrap.py
+++ b/tools/ocaml/libs/xl/genwrap.py
@@ -10,6 +10,7 @@ builtins = {
     "int":                  ("int",                    "%(c)s = Int_val(%(o)s)",            "Val_int(%(c)s)"  ),
     "char *":               ("string",                 "%(c)s = dup_String_val(gc, %(o)s)", "caml_copy_string(%(c)s)"),
     "libxl_domid":          ("domid",                  "%(c)s = Int_val(%(o)s)",            "Val_int(%(c)s)"  ),
+    "libxl_defbool":        ("bool option",            "%(c)s = Defbool_val(%(o)s)",        "Val_defbool(%(c)s)" ),
     "libxl_uuid":           ("int array",              "Uuid_val(gc, lg, &%(c)s, %(o)s)",   "Val_uuid(&%(c)s)"),
     "libxl_key_value_list": ("(string * string) list", None,                                None),
     "libxl_mac":            ("int array",              "Mac_val(gc, lg, &%(c)s, %(o)s)",    "Val_mac(&%(c)s)"),
diff --git a/tools/ocaml/libs/xl/xenlight_stubs.c b/tools/ocaml/libs/xl/xenlight_stubs.c
index f1511d46dd..2ba07fc579 100644
--- a/tools/ocaml/libs/xl/xenlight_stubs.c
+++ b/tools/ocaml/libs/xl/xenlight_stubs.c
@@ -195,6 +195,33 @@ static int Uuid_val(caml_gc *gc, struct caml_logger *lg, libxl_uuid *c_val, valu
 	CAMLreturn(0);
 }
 
+static value Val_defbool(libxl_defbool c_val)
+{
+	CAMLparam0();
+	CAMLlocal1(v);
+
+	if (libxl_defbool_is_default(c_val))
+		v = Val_none;
+	else {
+		bool b = libxl_defbool_val(c_val);
+		v = Val_some(b ? Val_bool(true) : Val_bool(false));
+	}
+	CAMLreturn(v);
+}
+
+static libxl_defbool Defbool_val(value v)
+{
+	CAMLparam1(v);
+	libxl_defbool db;
+	if (v == Val_none)
+		libxl_defbool_unset(&db);
+	else {
+		bool b = Bool_val(Some_val(v));
+		libxl_defbool_set(&db, b);
+	}
+	return db;
+}
+
 static value Val_hwcap(libxl_hwcap *c_val)
 {
 	CAMLparam0();
diff --git a/tools/python/genwrap.py b/tools/python/genwrap.py
index aa5c723c3d..af8a5e9c46 100644
--- a/tools/python/genwrap.py
+++ b/tools/python/genwrap.py
@@ -4,11 +4,13 @@ import sys,os
 
 import idl
 
-(TYPE_BOOL, TYPE_INT, TYPE_UINT, TYPE_STRING, TYPE_AGGREGATE) = range(5)
+(TYPE_DEFBOOL, TYPE_BOOL, TYPE_INT, TYPE_UINT, TYPE_STRING, TYPE_AGGREGATE) = range(6)
 
 def py_type(ty):
     if ty == idl.bool:
         return TYPE_BOOL
+    if ty.typename == "libxl_defbool":
+        return TYPE_DEFBOOL
     if isinstance(ty, idl.Enumeration):
         return TYPE_UINT
     if isinstance(ty, idl.Number):
@@ -44,6 +46,8 @@ def py_decls(ty):
         for f in ty.fields:
             if py_type(f.type) is not None:
                 continue
+            if py_type(f.type) == TYPE_DEFBOOL:
+                continue
             if ty.marshal_out():
                 l.append('_hidden PyObject *attrib__%s_get(%s *%s);'%(\
                     fsanitize(f.type.typename), f.type.typename, f.name))
@@ -62,6 +66,8 @@ def py_attrib_get(ty, f):
         l.append('    ret = (self->obj.%s) ? Py_True : Py_False;'%f.name)
         l.append('    Py_INCREF(ret);')
         l.append('    return ret;')
+    elif t == TYPE_DEFBOOL:
+        l.append('    return genwrap__defbool_get(&self->obj.%s);'%f.name)
     elif t == TYPE_INT:
         l.append('    return genwrap__ll_get(self->obj.%s);'%f.name)
     elif t == TYPE_UINT:
@@ -85,6 +91,8 @@ def py_attrib_set(ty, f):
     if t == TYPE_BOOL:
         l.append('    self->obj.%s = (NULL == v || Py_None == v || Py_False == v) ? 0 : 1;'%f.name)
         l.append('    return 0;')
+    elif t == TYPE_DEFBOOL:
+        l.append('    return genwrap__defbool_set(v, &self->obj.%s);'%f.name)
     elif t == TYPE_UINT or t == TYPE_INT:
         l.append('    %slong long tmp;'%(t == TYPE_UINT and 'unsigned ' or ''))
         l.append('    int ret;')
@@ -275,6 +283,8 @@ _hidden PyObject *genwrap__ull_get(unsigned long long val);
 _hidden int genwrap__ull_set(PyObject *v, unsigned long long *val, unsigned long long mask);
 _hidden PyObject *genwrap__ll_get(long long val);
 _hidden int genwrap__ll_set(PyObject *v, long long *val, long long mask);
+_hidden PyObject *genwrap__defbool_get(libxl_defbool *db);
+_hidden int genwrap__defbool_set(PyObject *v, libxl_defbool *db);
 
 """ % " ".join(sys.argv))
     for ty in [ty for ty in types if isinstance(ty, idl.Aggregate)]:
diff --git a/tools/python/xen/lowlevel/xl/xl.c b/tools/python/xen/lowlevel/xl/xl.c
index 625891a6bc..74c8c887e5 100644
--- a/tools/python/xen/lowlevel/xl/xl.c
+++ b/tools/python/xen/lowlevel/xl/xl.c
@@ -156,6 +156,21 @@ int genwrap__ll_set(PyObject *v, long long *val, long long mask)
     return 0;
 }
 
+PyObject *genwrap__defbool_get(libxl_defbool *db)
+{
+    PyObject *ret;
+    ret = libxl_defbool_val(*db) ? Py_True : Py_False;
+    Py_INCREF(ret);
+    return ret;
+}
+
+int genwrap__defbool_set(PyObject *v, libxl_defbool *db)
+{
+    bool val = !(NULL == v || Py_None == v || Py_False == v);
+    libxl_defbool_set(db, val);
+    return 0;
+}
+
 static int fixed_bytearray_set(PyObject *v, uint8_t *ptr, size_t len)
 {
     char *tmp;
@@ -762,11 +777,11 @@ PyMODINIT_FUNC initxl(void)
     Py_INCREF(xl_error_obj);
     PyModule_AddObject(m, "Error", xl_error_obj);
 
-    _INT_CONST(m, SHUTDOWN_poweroff);
-    _INT_CONST(m, SHUTDOWN_reboot);
-    _INT_CONST(m, SHUTDOWN_suspend);
-    _INT_CONST(m, SHUTDOWN_crash);
-    _INT_CONST(m, SHUTDOWN_watchdog);
+    _INT_CONST_LIBXL(m, SHUTDOWN_REASON_POWEROFF);
+    _INT_CONST_LIBXL(m, SHUTDOWN_REASON_REBOOT);
+    _INT_CONST_LIBXL(m, SHUTDOWN_REASON_SUSPEND);
+    _INT_CONST_LIBXL(m, SHUTDOWN_REASON_CRASH);
+    _INT_CONST_LIBXL(m, SHUTDOWN_REASON_WATCHDOG);
 
     genwrap__init(m);
 }