diff --git a/authz/listfile.c b/authz/listfile.c
index cd6163aa406a3930b1b36c3c5bf133ea750cc141..aaf930453d217553fdada5fa815243e2784e8543 100644
--- a/authz/listfile.c
+++ b/authz/listfile.c
@@ -122,6 +122,11 @@ qauthz_list_file_complete(UserCreatable *uc, Error **errp)
     QAuthZListFile *fauthz = QAUTHZ_LIST_FILE(uc);
     gchar *dir = NULL, *file = NULL;
 
+    if (!fauthz->filename) {
+        error_setg(errp, "filename not provided");
+        return;
+    }
+
     fauthz->list = qauthz_list_file_load(fauthz, errp);
 
     if (!fauthz->refresh) {
diff --git a/backends/rng-egd.c b/backends/rng-egd.c
index 20198ff26e2939155d82944dea1471a2c8bc95e6..4de142b9dc368195af7e65e13ed98c1109344859 100644
--- a/backends/rng-egd.c
+++ b/backends/rng-egd.c
@@ -135,12 +135,6 @@ static char *rng_egd_get_chardev(Object *obj, Error **errp)
     return NULL;
 }
 
-static void rng_egd_init(Object *obj)
-{
-    object_property_add_str(obj, "chardev",
-                            rng_egd_get_chardev, rng_egd_set_chardev);
-}
-
 static void rng_egd_finalize(Object *obj)
 {
     RngEgd *s = RNG_EGD(obj);
@@ -155,6 +149,8 @@ static void rng_egd_class_init(ObjectClass *klass, void *data)
 
     rbc->request_entropy = rng_egd_request_entropy;
     rbc->opened = rng_egd_opened;
+    object_class_property_add_str(klass, "chardev",
+                                  rng_egd_get_chardev, rng_egd_set_chardev);
 }
 
 static const TypeInfo rng_egd_info = {
@@ -162,7 +158,6 @@ static const TypeInfo rng_egd_info = {
     .parent = TYPE_RNG_BACKEND,
     .instance_size = sizeof(RngEgd),
     .class_init = rng_egd_class_init,
-    .instance_init = rng_egd_init,
     .instance_finalize = rng_egd_finalize,
 };
 
diff --git a/backends/rng-random.c b/backends/rng-random.c
index 245b12ab24570b5473ed92e88d6cae097e2c3ed6..7add272edddf3ec446ce50b3276deb065aeee9fd 100644
--- a/backends/rng-random.c
+++ b/backends/rng-random.c
@@ -108,10 +108,6 @@ static void rng_random_init(Object *obj)
 {
     RngRandom *s = RNG_RANDOM(obj);
 
-    object_property_add_str(obj, "filename",
-                            rng_random_get_filename,
-                            rng_random_set_filename);
-
     s->filename = g_strdup("/dev/urandom");
     s->fd = -1;
 }
@@ -134,6 +130,10 @@ static void rng_random_class_init(ObjectClass *klass, void *data)
 
     rbc->request_entropy = rng_random_request_entropy;
     rbc->opened = rng_random_opened;
+    object_class_property_add_str(klass, "filename",
+                                  rng_random_get_filename,
+                                  rng_random_set_filename);
+
 }
 
 static const TypeInfo rng_random_info = {
diff --git a/backends/rng.c b/backends/rng.c
index 484f04e8916c4e11e82b6f25f0815aa4d71ee433..3757b044855c64d8820c777766e8d19a1bbd77b3 100644
--- a/backends/rng.c
+++ b/backends/rng.c
@@ -105,10 +105,6 @@ static void rng_backend_init(Object *obj)
     RngBackend *s = RNG_BACKEND(obj);
 
     QSIMPLEQ_INIT(&s->requests);
-
-    object_property_add_bool(obj, "opened",
-                             rng_backend_prop_get_opened,
-                             rng_backend_prop_set_opened);
 }
 
 static void rng_backend_finalize(Object *obj)
@@ -123,6 +119,10 @@ static void rng_backend_class_init(ObjectClass *oc, void *data)
     UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
 
     ucc->complete = rng_backend_complete;
+
+    object_class_property_add_bool(oc, "opened",
+                                   rng_backend_prop_get_opened,
+                                   rng_backend_prop_set_opened);
 }
 
 static const TypeInfo rng_backend_info = {
diff --git a/backends/vhost-user.c b/backends/vhost-user.c
index ae8362d72139e3ec7d3b34a2e79891e06c5f2fc9..b366610e16e3181a2499be1c7884e5fba65e08c3 100644
--- a/backends/vhost-user.c
+++ b/backends/vhost-user.c
@@ -175,9 +175,9 @@ static char *get_chardev(Object *obj, Error **errp)
     return NULL;
 }
 
-static void vhost_user_backend_init(Object *obj)
+static void vhost_user_backend_class_init(ObjectClass *oc, void *data)
 {
-    object_property_add_str(obj, "chardev", get_chardev, set_chardev);
+    object_class_property_add_str(oc, "chardev", get_chardev, set_chardev);
 }
 
 static void vhost_user_backend_finalize(Object *obj)
@@ -195,7 +195,7 @@ static const TypeInfo vhost_user_backend_info = {
     .name = TYPE_VHOST_USER_BACKEND,
     .parent = TYPE_OBJECT,
     .instance_size = sizeof(VhostUserBackend),
-    .instance_init = vhost_user_backend_init,
+    .class_init = vhost_user_backend_class_init,
     .instance_finalize = vhost_user_backend_finalize,
 };
 
diff --git a/hw/display/vga-pci.c b/hw/display/vga-pci.c
index e5d9af5868659697b25209d403cca2bb770a77af..48d29630ab773832e11448dab50251819bc9bc83 100644
--- a/hw/display/vga-pci.c
+++ b/hw/display/vga-pci.c
@@ -267,13 +267,6 @@ static void pci_std_vga_realize(PCIDevice *dev, Error **errp)
     }
 }
 
-static void pci_std_vga_init(Object *obj)
-{
-    /* Expose framebuffer byteorder via QOM */
-    object_property_add_bool(obj, "big-endian-framebuffer",
-                             vga_get_big_endian_fb, vga_set_big_endian_fb);
-}
-
 static void pci_secondary_vga_realize(PCIDevice *dev, Error **errp)
 {
     PCIVGAState *d = PCI_VGA(dev);
@@ -386,6 +379,10 @@ static void vga_class_init(ObjectClass *klass, void *data)
     k->class_id = PCI_CLASS_DISPLAY_VGA;
     device_class_set_props(dc, vga_pci_properties);
     dc->hotpluggable = false;
+
+    /* Expose framebuffer byteorder via QOM */
+    object_class_property_add_bool(klass, "big-endian-framebuffer",
+                                   vga_get_big_endian_fb, vga_set_big_endian_fb);
 }
 
 static void secondary_class_init(ObjectClass *klass, void *data)
@@ -403,7 +400,6 @@ static void secondary_class_init(ObjectClass *klass, void *data)
 static const TypeInfo vga_info = {
     .name          = "VGA",
     .parent        = TYPE_PCI_VGA,
-    .instance_init = pci_std_vga_init,
     .class_init    = vga_class_init,
 };
 
diff --git a/net/can/can_socketcan.c b/net/can/can_socketcan.c
index 92b1f79385ef23dd94b6fc1a3b94e352e224eb80..4b68f60c6b663afed4e94be80fa6bea7ef566849 100644
--- a/net/can/can_socketcan.c
+++ b/net/can/can_socketcan.c
@@ -194,6 +194,11 @@ static void can_host_socketcan_connect(CanHostState *ch, Error **errp)
     struct sockaddr_can addr;
     struct ifreq ifr;
 
+    if (!c->ifname) {
+        error_setg(errp, "'if' property not set");
+        return;
+    }
+
     /* open socket */
     s = qemu_socket(PF_CAN, SOCK_RAW, CAN_RAW);
     if (s < 0) {
diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index 9eafbe369075041878f8dcaf33a908f41c6f5858..5d713c852843d53bd68c290e27811d05d70392b9 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -6925,44 +6925,12 @@ static void x86_cpu_initfn(Object *obj)
     env->nr_dies = 1;
     cpu_set_cpustate_pointers(cpu);
 
-    object_property_add(obj, "family", "int",
-                        x86_cpuid_version_get_family,
-                        x86_cpuid_version_set_family, NULL, NULL);
-    object_property_add(obj, "model", "int",
-                        x86_cpuid_version_get_model,
-                        x86_cpuid_version_set_model, NULL, NULL);
-    object_property_add(obj, "stepping", "int",
-                        x86_cpuid_version_get_stepping,
-                        x86_cpuid_version_set_stepping, NULL, NULL);
-    object_property_add_str(obj, "vendor",
-                            x86_cpuid_get_vendor,
-                            x86_cpuid_set_vendor);
-    object_property_add_str(obj, "model-id",
-                            x86_cpuid_get_model_id,
-                            x86_cpuid_set_model_id);
-    object_property_add(obj, "tsc-frequency", "int",
-                        x86_cpuid_get_tsc_freq,
-                        x86_cpuid_set_tsc_freq, NULL, NULL);
     object_property_add(obj, "feature-words", "X86CPUFeatureWordInfo",
                         x86_cpu_get_feature_words,
                         NULL, NULL, (void *)env->features);
     object_property_add(obj, "filtered-features", "X86CPUFeatureWordInfo",
                         x86_cpu_get_feature_words,
                         NULL, NULL, (void *)cpu->filtered_features);
-    /*
-     * The "unavailable-features" property has the same semantics as
-     * CpuDefinitionInfo.unavailable-features on the "query-cpu-definitions"
-     * QMP command: they list the features that would have prevented the
-     * CPU from running if the "enforce" flag was set.
-     */
-    object_property_add(obj, "unavailable-features", "strList",
-                        x86_cpu_get_unavailable_features,
-                        NULL, NULL, NULL);
-
-#if !defined(CONFIG_USER_ONLY)
-    object_property_add(obj, "crash-information", "GuestPanicInformation",
-                        x86_cpu_get_crash_info_qom, NULL, NULL, NULL);
-#endif
 
     for (w = 0; w < FEATURE_WORDS; w++) {
         int bitnr;
@@ -7312,6 +7280,40 @@ static void x86_cpu_common_class_init(ObjectClass *oc, void *data)
     cc->disas_set_info = x86_disas_set_info;
 
     dc->user_creatable = true;
+
+    object_class_property_add(oc, "family", "int",
+                              x86_cpuid_version_get_family,
+                              x86_cpuid_version_set_family, NULL, NULL);
+    object_class_property_add(oc, "model", "int",
+                              x86_cpuid_version_get_model,
+                              x86_cpuid_version_set_model, NULL, NULL);
+    object_class_property_add(oc, "stepping", "int",
+                              x86_cpuid_version_get_stepping,
+                              x86_cpuid_version_set_stepping, NULL, NULL);
+    object_class_property_add_str(oc, "vendor",
+                                  x86_cpuid_get_vendor,
+                                  x86_cpuid_set_vendor);
+    object_class_property_add_str(oc, "model-id",
+                                  x86_cpuid_get_model_id,
+                                  x86_cpuid_set_model_id);
+    object_class_property_add(oc, "tsc-frequency", "int",
+                              x86_cpuid_get_tsc_freq,
+                              x86_cpuid_set_tsc_freq, NULL, NULL);
+    /*
+     * The "unavailable-features" property has the same semantics as
+     * CpuDefinitionInfo.unavailable-features on the "query-cpu-definitions"
+     * QMP command: they list the features that would have prevented the
+     * CPU from running if the "enforce" flag was set.
+     */
+    object_class_property_add(oc, "unavailable-features", "strList",
+                              x86_cpu_get_unavailable_features,
+                              NULL, NULL, NULL);
+
+#if !defined(CONFIG_USER_ONLY)
+    object_class_property_add(oc, "crash-information", "GuestPanicInformation",
+                              x86_cpu_get_crash_info_qom, NULL, NULL, NULL);
+#endif
+
 }
 
 static const TypeInfo x86_cpu_type_info = {
diff --git a/ui/input-barrier.c b/ui/input-barrier.c
index a047919fde7fc4cd8b933ec834bd59abe275955d..81b8d04ec8dae63f8da2e70917c94b2a6869499f 100644
--- a/ui/input-barrier.c
+++ b/ui/input-barrier.c
@@ -689,28 +689,6 @@ static void input_barrier_instance_init(Object *obj)
     ib->y_origin = 0;
     ib->width = 1920;
     ib->height = 1080;
-
-    object_property_add_str(obj, "name",
-                            input_barrier_get_name,
-                            input_barrier_set_name);
-    object_property_add_str(obj, "server",
-                            input_barrier_get_server,
-                            input_barrier_set_server);
-    object_property_add_str(obj, "port",
-                            input_barrier_get_port,
-                            input_barrier_set_port);
-    object_property_add_str(obj, "x-origin",
-                            input_barrier_get_x_origin,
-                            input_barrier_set_x_origin);
-    object_property_add_str(obj, "y-origin",
-                            input_barrier_get_y_origin,
-                            input_barrier_set_y_origin);
-    object_property_add_str(obj, "width",
-                            input_barrier_get_width,
-                            input_barrier_set_width);
-    object_property_add_str(obj, "height",
-                            input_barrier_get_height,
-                            input_barrier_set_height);
 }
 
 static void input_barrier_class_init(ObjectClass *oc, void *data)
@@ -718,6 +696,28 @@ static void input_barrier_class_init(ObjectClass *oc, void *data)
     UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
 
     ucc->complete = input_barrier_complete;
+
+    object_class_property_add_str(oc, "name",
+                                  input_barrier_get_name,
+                                  input_barrier_set_name);
+    object_class_property_add_str(oc, "server",
+                                  input_barrier_get_server,
+                                  input_barrier_set_server);
+    object_class_property_add_str(oc, "port",
+                                  input_barrier_get_port,
+                                  input_barrier_set_port);
+    object_class_property_add_str(oc, "x-origin",
+                                  input_barrier_get_x_origin,
+                                  input_barrier_set_x_origin);
+    object_class_property_add_str(oc, "y-origin",
+                                  input_barrier_get_y_origin,
+                                  input_barrier_set_y_origin);
+    object_class_property_add_str(oc, "width",
+                                  input_barrier_get_width,
+                                  input_barrier_set_width);
+    object_class_property_add_str(oc, "height",
+                                  input_barrier_get_height,
+                                  input_barrier_set_height);
 }
 
 static const TypeInfo input_barrier_info = {
diff --git a/ui/input-linux.c b/ui/input-linux.c
index 34cc531190f9d11cac015d61e7c68b1e834d3984..05c0c988199a99e51dfd57967b0eb994d82276fc 100644
--- a/ui/input-linux.c
+++ b/ui/input-linux.c
@@ -490,19 +490,6 @@ static void input_linux_set_grab_toggle(Object *obj, int value,
 
 static void input_linux_instance_init(Object *obj)
 {
-    object_property_add_str(obj, "evdev",
-                            input_linux_get_evdev,
-                            input_linux_set_evdev);
-    object_property_add_bool(obj, "grab_all",
-                             input_linux_get_grab_all,
-                             input_linux_set_grab_all);
-    object_property_add_bool(obj, "repeat",
-                             input_linux_get_repeat,
-                             input_linux_set_repeat);
-    object_property_add_enum(obj, "grab-toggle", "GrabToggleKeys",
-                             &GrabToggleKeys_lookup,
-                             input_linux_get_grab_toggle,
-                             input_linux_set_grab_toggle);
 }
 
 static void input_linux_class_init(ObjectClass *oc, void *data)
@@ -510,6 +497,20 @@ static void input_linux_class_init(ObjectClass *oc, void *data)
     UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
 
     ucc->complete = input_linux_complete;
+
+    object_class_property_add_str(oc, "evdev",
+                                  input_linux_get_evdev,
+                                  input_linux_set_evdev);
+    object_class_property_add_bool(oc, "grab_all",
+                                   input_linux_get_grab_all,
+                                   input_linux_set_grab_all);
+    object_class_property_add_bool(oc, "repeat",
+                                   input_linux_get_repeat,
+                                   input_linux_set_repeat);
+    object_class_property_add_enum(oc, "grab-toggle", "GrabToggleKeys",
+                                   &GrabToggleKeys_lookup,
+                                   input_linux_get_grab_toggle,
+                                   input_linux_set_grab_toggle);
 }
 
 static const TypeInfo input_linux_info = {