[Qemu-devel] [PATCH 0/7] propagate Errors to do_device_add()

[Qemu-devel] [PATCH 0/7] propagate Errors to do_device_add()

[Laszlo Ersek]

This series is the first in converting do_device_add() to qapi.

The following call chains have been modified:

  do_device_add -> qemu_find_opts -> error_report
  do_device_add -> qdev_device_add -> qerror_report
  do_device_add -> qdev_device_add -> qbus_find -> qbus_find_recursive -> qerror_report
  do_device_add -> qdev_device_add -> qbus_find -> qerror_report
  do_device_add -> qdev_device_add -> set_property -> qdev_prop_parse -> qerror_report_err

The following call chains
- all depend on !monitor_cur_is_qmp() at some level (marked with *),
- all print informative messages (not errors per se),
- are the next step in the conversion -- ultimately they belong in HMP:

  do_device_add -> qemu_opts_from_qdict -> qemu_opts_create -> error_printf_unless_qmp*
  do_device_add -> qemu_opts_from_qdict -> qemu_opts_from_qdict_1 -> qemu_opt_set_err -> opt_set -> qemu_opt_parse -> parse_option_size -> error_printf_unless_qmp*
  do_device_add* -> qdev_device_help -> qdev_print_devinfo -> error_printf
  do_device_add* -> qdev_device_help -> error_printf
  do_device_add -> qdev_device_add -> qbus_find* -> qbus_list_dev -> error_printf
  do_device_add -> qdev_device_add -> qbus_find* -> qbus_list_bus -> error_printf

Laszlo Ersek (7):
  remove some trailing whitespace
  do_device_add(): look up "device" opts list with qemu_find_opts_err()
  qdev_prop_parse(): report errors via Error
  qbus_find_recursive(): reorganize
  qbus_find_recursive(): terminate search by name in case of fatal
    error
  qbus_find(): report errors via Error
  qdev_device_add(): report errors with Error

 hw/qdev-monitor.h    |    3 +-
 hw/qdev-properties.h |    4 +-
 hw/qdev-monitor.c    |  124 ++++++++++++++++++++++++++++++--------------------
 hw/qdev-properties.c |   12 +++--
 vl.c                 |   17 ++++--
 5 files changed, 99 insertions(+), 61 deletions(-)

[Qemu-devel] [PATCH 1/7] remove some trailing whitespace

[Laszlo Ersek]

Signed-off-by: Laszlo Ersek <lersek@redhat.com>
---
 hw/qdev-monitor.c |    2 +-
 vl.c              |    8 ++++----
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/hw/qdev-monitor.c b/hw/qdev-monitor.c
index 4e2a92b..3ec9e49 100644
--- a/hw/qdev-monitor.c
+++ b/hw/qdev-monitor.c
@@ -490,7 +490,7 @@ DeviceState *qdev_device_add(QemuOpts *opts)
         object_property_add_child(qdev_get_peripheral_anon(), name,
                                   OBJECT(qdev), NULL);
         g_free(name);
-    }        
+    }
     if (qdev_init(qdev) < 0) {
         qerror_report(QERR_DEVICE_INIT_FAILED, driver);
         return NULL;
diff --git a/vl.c b/vl.c
index 910abb6..44656d8 100644
--- a/vl.c
+++ b/vl.c
@@ -2444,7 +2444,7 @@ static int virtcon_parse(const char *devname)
         qemu_opt_set(bus_opts, "driver", "virtio-serial-s390");
     } else {
         qemu_opt_set(bus_opts, "driver", "virtio-serial-pci");
-    } 
+    }
 
     dev_opts = qemu_opts_create_nofail(device);
     qemu_opt_set(dev_opts, "driver", "virtconsole");
@@ -2496,7 +2496,7 @@ static int sclp_parse(const char *devname)
 }
 
 static int debugcon_parse(const char *devname)
-{   
+{
     QemuOpts *opts;
 
     if (!qemu_chr_new("debugcon", devname, NULL)) {
@@ -3608,8 +3608,8 @@ int main(int argc, char **argv, char **envp)
 			}
 			p += 8;
 			os_set_proc_name(p);
-		     }	
-		 }	
+		     }
+		 }
                 break;
             case QEMU_OPTION_prom_env:
                 if (nb_prom_envs >= MAX_PROM_ENVS) {
-- 
1.7.1

[Qemu-devel] [PATCH 2/7] do_device_add(): look up "device" opts list with qemu_find_opts_err()

[Laszlo Ersek]

Signed-off-by: Laszlo Ersek <lersek@redhat.com>
---
 hw/qdev-monitor.c |    7 +++++--
 1 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/hw/qdev-monitor.c b/hw/qdev-monitor.c
index 3ec9e49..32be5a2 100644
--- a/hw/qdev-monitor.c
+++ b/hw/qdev-monitor.c
@@ -590,14 +590,17 @@ void do_info_qdm(Monitor *mon, const QDict *qdict)
 int do_device_add(Monitor *mon, const QDict *qdict, QObject **ret_data)
 {
     Error *local_err = NULL;
+    QemuOptsList *list;
     QemuOpts *opts;
 
-    opts = qemu_opts_from_qdict(qemu_find_opts("device"), qdict, &local_err);
-    if (error_is_set(&local_err)) {
+    if ((list = qemu_find_opts_err("device", &local_err)) == NULL ||
+        (opts = qemu_opts_from_qdict(list, qdict, &local_err)) == NULL) {
+        assert(error_is_set(&local_err));
         qerror_report_err(local_err);
         error_free(local_err);
         return -1;
     }
+
     if (!monitor_cur_is_qmp() && qdev_device_help(opts)) {
         qemu_opts_del(opts);
         return 0;
-- 
1.7.1

[Qemu-devel] [PATCH 3/7] qdev_prop_parse(): report errors via Error

[Laszlo Ersek]

Signed-off-by: Laszlo Ersek <lersek@redhat.com>
---
 hw/qdev-properties.h |    4 +++-
 hw/qdev-monitor.c    |   26 +++++++++++++++++++++-----
 hw/qdev-properties.c |   12 ++++++++----
 3 files changed, 32 insertions(+), 10 deletions(-)

diff --git a/hw/qdev-properties.h b/hw/qdev-properties.h
index ddcf774..e33f31b 100644
--- a/hw/qdev-properties.h
+++ b/hw/qdev-properties.h
@@ -2,6 +2,7 @@
 #define QEMU_QDEV_PROPERTIES_H
 
 #include "qdev-core.h"
+#include "qapi/error.h"
 
 /*** qdev-properties.c ***/
 
@@ -99,7 +100,8 @@ extern PropertyInfo qdev_prop_pci_host_devaddr;
 
 /* Set properties between creation and init.  */
 void *qdev_get_prop_ptr(DeviceState *dev, Property *prop);
-int qdev_prop_parse(DeviceState *dev, const char *name, const char *value);
+int qdev_prop_parse(DeviceState *dev, const char *name, const char *value,
+                    Error **errp);
 void qdev_prop_set_bit(DeviceState *dev, const char *name, bool value);
 void qdev_prop_set_uint8(DeviceState *dev, const char *name, uint8_t value);
 void qdev_prop_set_uint16(DeviceState *dev, const char *name, uint16_t value);
diff --git a/hw/qdev-monitor.c b/hw/qdev-monitor.c
index 32be5a2..691bab5 100644
--- a/hw/qdev-monitor.c
+++ b/hw/qdev-monitor.c
@@ -100,16 +100,23 @@ static void qdev_print_devinfo(ObjectClass *klass, void *opaque)
     error_printf("\n");
 }
 
+typedef struct {
+    DeviceState *dev;
+    Error **errp;
+} PropertyContext;
+
 static int set_property(const char *name, const char *value, void *opaque)
 {
-    DeviceState *dev = opaque;
+    PropertyContext *ctx = opaque;
+    Error *err = NULL;
 
     if (strcmp(name, "driver") == 0)
         return 0;
     if (strcmp(name, "bus") == 0)
         return 0;
 
-    if (qdev_prop_parse(dev, name, value) == -1) {
+    if (qdev_prop_parse(ctx->dev, name, value, &err) == -1) {
+        error_propagate(ctx->errp, err);
         return -1;
     }
     return 0;
@@ -415,6 +422,7 @@ DeviceState *qdev_device_add(QemuOpts *opts)
     const char *driver, *path, *id;
     DeviceState *qdev;
     BusState *bus;
+    Error *local_err = NULL;
 
     driver = qemu_opt_get(opts, "driver");
     if (!driver) {
@@ -477,10 +485,18 @@ DeviceState *qdev_device_add(QemuOpts *opts)
     if (id) {
         qdev->id = id;
     }
-    if (qemu_opt_foreach(opts, set_property, qdev, 1) != 0) {
-        qdev_free(qdev);
-        return NULL;
+
+    {
+        PropertyContext ctx = { .dev = qdev, .errp = &local_err };
+
+        if (qemu_opt_foreach(opts, set_property, &ctx, 1) != 0) {
+            qerror_report_err(local_err);
+            error_free(local_err);
+            qdev_free(qdev);
+            return NULL;
+        }
     }
+
     if (qdev->id) {
         object_property_add_child(qdev_get_peripheral(), qdev->id,
                                   OBJECT(qdev), NULL);
diff --git a/hw/qdev-properties.c b/hw/qdev-properties.c
index a8a31f5..8e3d014 100644
--- a/hw/qdev-properties.c
+++ b/hw/qdev-properties.c
@@ -835,7 +835,8 @@ void error_set_from_qdev_prop_error(Error **errp, int ret, DeviceState *dev,
     }
 }
 
-int qdev_prop_parse(DeviceState *dev, const char *name, const char *value)
+int qdev_prop_parse(DeviceState *dev, const char *name, const char *value,
+                    Error **errp)
 {
     char *legacy_name;
     Error *err = NULL;
@@ -849,8 +850,7 @@ int qdev_prop_parse(DeviceState *dev, const char *name, const char *value)
     g_free(legacy_name);
 
     if (err) {
-        qerror_report_err(err);
-        error_free(err);
+        error_propagate(errp, err);
         return -1;
     }
     return 0;
@@ -962,10 +962,14 @@ void qdev_prop_set_globals(DeviceState *dev)
     do {
         GlobalProperty *prop;
         QTAILQ_FOREACH(prop, &global_props, next) {
+            Error *err = NULL;
+
             if (strcmp(object_class_get_name(class), prop->driver) != 0) {
                 continue;
             }
-            if (qdev_prop_parse(dev, prop->property, prop->value) != 0) {
+            if (qdev_prop_parse(dev, prop->property, prop->value, &err) != 0) {
+                qerror_report_err(err);
+                error_free(err);
                 exit(1);
             }
         }
-- 
1.7.1

[Qemu-devel] [PATCH 4/7] qbus_find_recursive(): reorganize

[Laszlo Ersek]

Eliminate the "match" variable, and move the remaining locals to the
narrowest possible scope.

Signed-off-by: Laszlo Ersek <lersek@redhat.com>
---
 hw/qdev-monitor.c |   35 ++++++++++++++++-------------------
 1 files changed, 16 insertions(+), 19 deletions(-)

diff --git a/hw/qdev-monitor.c b/hw/qdev-monitor.c
index 691bab5..284dafa 100644
--- a/hw/qdev-monitor.c
+++ b/hw/qdev-monitor.c
@@ -288,38 +288,35 @@ static DeviceState *qbus_find_dev(BusState *bus, char *elem)
 }
 
 static BusState *qbus_find_recursive(BusState *bus, const char *name,
-                                     const char *bus_typename)
+                                     const char *type)
 {
-    BusClass *bus_class = BUS_GET_CLASS(bus);
     BusChild *kid;
-    BusState *child, *ret;
-    int match = 1;
 
-    if (name && (strcmp(bus->name, name) != 0)) {
-        match = 0;
-    }
-    if (bus_typename && !object_dynamic_cast(OBJECT(bus), bus_typename)) {
-        match = 0;
-    }
-    if ((bus_class->max_dev != 0) && (bus_class->max_dev <= bus->max_index)) {
+    if ((name == NULL || strcmp(bus->name, name) == 0) &&
+        (type == NULL || object_dynamic_cast(OBJECT(bus), type) != NULL)) {
+        BusClass *bus_class = BUS_GET_CLASS(bus);
+
+        /* name (if any) and type (if any) match; check free slots */
+        if (bus_class->max_dev == 0 || bus->max_index < bus_class->max_dev) {
+            return bus;
+        }
+
+        /* bus is full -- fatal error for search by name */
         if (name != NULL) {
-            /* bus was explicitly specified: return an error. */
             qerror_report(ERROR_CLASS_GENERIC_ERROR, "Bus '%s' is full",
                           bus->name);
             return NULL;
-        } else {
-            /* bus was not specified: try to find another one. */
-            match = 0;
         }
     }
-    if (match) {
-        return bus;
-    }
 
     QTAILQ_FOREACH(kid, &bus->children, sibling) {
         DeviceState *dev = kid->child;
+        BusState *child;
+
         QLIST_FOREACH(child, &dev->child_bus, sibling) {
-            ret = qbus_find_recursive(child, name, bus_typename);
+            BusState *ret;
+
+            ret = qbus_find_recursive(child, name, type);
             if (ret) {
                 return ret;
             }
-- 
1.7.1

[Qemu-devel] [PATCH 5/7] qbus_find_recursive(): terminate search by name in case of fatal error

[Laszlo Ersek]

Use an Error to communicate the "stop the search" message.

Signed-off-by: Laszlo Ersek <lersek@redhat.com>
---
 hw/qdev-monitor.c |   24 ++++++++++++++++--------
 1 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/hw/qdev-monitor.c b/hw/qdev-monitor.c
index 284dafa..83540fc 100644
--- a/hw/qdev-monitor.c
+++ b/hw/qdev-monitor.c
@@ -288,7 +288,7 @@ static DeviceState *qbus_find_dev(BusState *bus, char *elem)
 }
 
 static BusState *qbus_find_recursive(BusState *bus, const char *name,
-                                     const char *type)
+                                     const char *type, Error **errp)
 {
     BusChild *kid;
 
@@ -303,8 +303,7 @@ static BusState *qbus_find_recursive(BusState *bus, const char *name,
 
         /* bus is full -- fatal error for search by name */
         if (name != NULL) {
-            qerror_report(ERROR_CLASS_GENERIC_ERROR, "Bus '%s' is full",
-                          bus->name);
+            error_setg(errp, "Bus '%s' is full", bus->name);
             return NULL;
         }
     }
@@ -316,8 +315,8 @@ static BusState *qbus_find_recursive(BusState *bus, const char *name,
         QLIST_FOREACH(child, &dev->child_bus, sibling) {
             BusState *ret;
 
-            ret = qbus_find_recursive(child, name, type);
-            if (ret) {
+            ret = qbus_find_recursive(child, name, type, errp);
+            if (ret || error_is_set(errp)) {
                 return ret;
             }
         }
@@ -337,13 +336,20 @@ static BusState *qbus_find(const char *path)
         bus = sysbus_get_default();
         pos = 0;
     } else {
+        Error *err = NULL;
+
         if (sscanf(path, "%127[^/]%n", elem, &len) != 1) {
             assert(!path[0]);
             elem[0] = len = 0;
         }
-        bus = qbus_find_recursive(sysbus_get_default(), elem, NULL);
+        bus = qbus_find_recursive(sysbus_get_default(), elem, NULL, &err);
         if (!bus) {
-            qerror_report(QERR_BUS_NOT_FOUND, elem);
+            if (error_is_set(&err)) {
+                qerror_report_err(err);
+                error_free(err);
+            } else {
+                qerror_report(QERR_BUS_NOT_FOUND, elem);
+            }
             return NULL;
         }
         pos = len;
@@ -458,8 +464,10 @@ DeviceState *qdev_device_add(QemuOpts *opts)
             return NULL;
         }
     } else {
-        bus = qbus_find_recursive(sysbus_get_default(), NULL, k->bus_type);
+        bus = qbus_find_recursive(sysbus_get_default(), NULL, k->bus_type,
+                                  &local_err);
         if (!bus) {
+            assert(!error_is_set(&local_err));
             qerror_report(QERR_NO_BUS_FOR_DEVICE,
                           k->bus_type, driver);
             return NULL;
-- 
1.7.1

[Qemu-devel] [PATCH 6/7] qbus_find(): report errors via Error

[Laszlo Ersek]

Signed-off-by: Laszlo Ersek <lersek@redhat.com>
---
 hw/qdev-monitor.c |   29 +++++++++++++++--------------
 1 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/hw/qdev-monitor.c b/hw/qdev-monitor.c
index 83540fc..0c01b04 100644
--- a/hw/qdev-monitor.c
+++ b/hw/qdev-monitor.c
@@ -324,7 +324,7 @@ static BusState *qbus_find_recursive(BusState *bus, const char *name,
     return NULL;
 }
 
-static BusState *qbus_find(const char *path)
+static BusState *qbus_find(const char *path, Error **errp)
 {
     DeviceState *dev;
     BusState *bus;
@@ -336,20 +336,19 @@ static BusState *qbus_find(const char *path)
         bus = sysbus_get_default();
         pos = 0;
     } else {
-        Error *err = NULL;
+        Error *find_err = NULL;
 
         if (sscanf(path, "%127[^/]%n", elem, &len) != 1) {
             assert(!path[0]);
             elem[0] = len = 0;
         }
-        bus = qbus_find_recursive(sysbus_get_default(), elem, NULL, &err);
+        bus = qbus_find_recursive(sysbus_get_default(), elem, NULL, &find_err);
         if (!bus) {
-            if (error_is_set(&err)) {
-                qerror_report_err(err);
-                error_free(err);
-            } else {
-                qerror_report(QERR_BUS_NOT_FOUND, elem);
-            }
+            Error *not_found;
+
+            error_set(&not_found, QERR_BUS_NOT_FOUND, elem);
+            error_propagate(errp, find_err);
+            error_propagate(errp, not_found);
             return NULL;
         }
         pos = len;
@@ -372,7 +371,7 @@ static BusState *qbus_find(const char *path)
         pos += len;
         dev = qbus_find_dev(bus, elem);
         if (!dev) {
-            qerror_report(QERR_DEVICE_NOT_FOUND, elem);
+            error_set(errp, QERR_DEVICE_NOT_FOUND, elem);
             if (!monitor_cur_is_qmp()) {
                 qbus_list_dev(bus);
             }
@@ -388,12 +387,12 @@ static BusState *qbus_find(const char *path)
              * one child bus accept it nevertheless */
             switch (dev->num_child_bus) {
             case 0:
-                qerror_report(QERR_DEVICE_NO_BUS, elem);
+                error_set(errp, QERR_DEVICE_NO_BUS, elem);
                 return NULL;
             case 1:
                 return QLIST_FIRST(&dev->child_bus);
             default:
-                qerror_report(QERR_DEVICE_MULTIPLE_BUSSES, elem);
+                error_set(errp, QERR_DEVICE_MULTIPLE_BUSSES, elem);
                 if (!monitor_cur_is_qmp()) {
                     qbus_list_bus(dev);
                 }
@@ -409,7 +408,7 @@ static BusState *qbus_find(const char *path)
         pos += len;
         bus = qbus_find_bus(dev, elem);
         if (!bus) {
-            qerror_report(QERR_BUS_NOT_FOUND, elem);
+            error_set(errp, QERR_BUS_NOT_FOUND, elem);
             if (!monitor_cur_is_qmp()) {
                 qbus_list_bus(dev);
             }
@@ -454,8 +453,10 @@ DeviceState *qdev_device_add(QemuOpts *opts)
     /* find bus */
     path = qemu_opt_get(opts, "bus");
     if (path != NULL) {
-        bus = qbus_find(path);
+        bus = qbus_find(path, &local_err);
         if (!bus) {
+            qerror_report_err(local_err);
+            error_free(local_err);
             return NULL;
         }
         if (!object_dynamic_cast(OBJECT(bus), k->bus_type)) {
-- 
1.7.1

[Qemu-devel] [PATCH 7/7] qdev_device_add(): report errors with Error

[Laszlo Ersek]

Signed-off-by: Laszlo Ersek <lersek@redhat.com>
---
 hw/qdev-monitor.h |    3 ++-
 hw/qdev-monitor.c |   29 +++++++++++++++--------------
 vl.c              |    9 +++++++--
 3 files changed, 24 insertions(+), 17 deletions(-)

diff --git a/hw/qdev-monitor.h b/hw/qdev-monitor.h
index 9ec4850..3760bf5 100644
--- a/hw/qdev-monitor.h
+++ b/hw/qdev-monitor.h
@@ -3,6 +3,7 @@
 
 #include "qdev-core.h"
 #include "monitor/monitor.h"
+#include "qapi/error.h"
 
 /*** monitor commands ***/
 
@@ -11,6 +12,6 @@ void do_info_qdm(Monitor *mon, const QDict *qdict);
 int do_device_add(Monitor *mon, const QDict *qdict, QObject **ret_data);
 int do_device_del(Monitor *mon, const QDict *qdict, QObject **ret_data);
 int qdev_device_help(QemuOpts *opts);
-DeviceState *qdev_device_add(QemuOpts *opts);
+DeviceState *qdev_device_add(QemuOpts *opts, Error **errp);
 
 #endif
diff --git a/hw/qdev-monitor.c b/hw/qdev-monitor.c
index 0c01b04..7e103af 100644
--- a/hw/qdev-monitor.c
+++ b/hw/qdev-monitor.c
@@ -417,7 +417,7 @@ static BusState *qbus_find(const char *path, Error **errp)
     }
 }
 
-DeviceState *qdev_device_add(QemuOpts *opts)
+DeviceState *qdev_device_add(QemuOpts *opts, Error **errp)
 {
     ObjectClass *obj;
     DeviceClass *k;
@@ -428,7 +428,7 @@ DeviceState *qdev_device_add(QemuOpts *opts)
 
     driver = qemu_opt_get(opts, "driver");
     if (!driver) {
-        qerror_report(QERR_MISSING_PARAMETER, "driver");
+        error_set(errp, QERR_MISSING_PARAMETER, "driver");
         return NULL;
     }
 
@@ -444,7 +444,7 @@ DeviceState *qdev_device_add(QemuOpts *opts)
     }
 
     if (!obj) {
-        qerror_report(QERR_INVALID_PARAMETER_VALUE, "driver", "device type");
+        error_set(errp, QERR_INVALID_PARAMETER_VALUE, "driver", "device type");
         return NULL;
     }
 
@@ -455,13 +455,12 @@ DeviceState *qdev_device_add(QemuOpts *opts)
     if (path != NULL) {
         bus = qbus_find(path, &local_err);
         if (!bus) {
-            qerror_report_err(local_err);
-            error_free(local_err);
+            error_propagate(errp, local_err);
             return NULL;
         }
         if (!object_dynamic_cast(OBJECT(bus), k->bus_type)) {
-            qerror_report(QERR_BAD_BUS_FOR_DEVICE,
-                          driver, object_get_typename(OBJECT(bus)));
+            error_set(errp, QERR_BAD_BUS_FOR_DEVICE,
+                      driver, object_get_typename(OBJECT(bus)));
             return NULL;
         }
     } else {
@@ -469,13 +468,12 @@ DeviceState *qdev_device_add(QemuOpts *opts)
                                   &local_err);
         if (!bus) {
             assert(!error_is_set(&local_err));
-            qerror_report(QERR_NO_BUS_FOR_DEVICE,
-                          k->bus_type, driver);
+            error_set(errp, QERR_NO_BUS_FOR_DEVICE, k->bus_type, driver);
             return NULL;
         }
     }
     if (qdev_hotplug && !bus->allow_hotplug) {
-        qerror_report(QERR_BUS_NO_HOTPLUG, bus->name);
+        error_set(errp, QERR_BUS_NO_HOTPLUG, bus->name);
         return NULL;
     }
 
@@ -496,8 +494,7 @@ DeviceState *qdev_device_add(QemuOpts *opts)
         PropertyContext ctx = { .dev = qdev, .errp = &local_err };
 
         if (qemu_opt_foreach(opts, set_property, &ctx, 1) != 0) {
-            qerror_report_err(local_err);
-            error_free(local_err);
+            error_propagate(errp, local_err);
             qdev_free(qdev);
             return NULL;
         }
@@ -514,7 +511,7 @@ DeviceState *qdev_device_add(QemuOpts *opts)
         g_free(name);
     }
     if (qdev_init(qdev) < 0) {
-        qerror_report(QERR_DEVICE_INIT_FAILED, driver);
+        error_set(errp, QERR_DEVICE_INIT_FAILED, driver);
         return NULL;
     }
     qdev->opts = opts;
@@ -627,7 +624,11 @@ int do_device_add(Monitor *mon, const QDict *qdict, QObject **ret_data)
         qemu_opts_del(opts);
         return 0;
     }
-    if (!qdev_device_add(opts)) {
+
+    if (!qdev_device_add(opts, &local_err)) {
+        assert(error_is_set(&local_err));
+        qerror_report_err(local_err);
+        error_free(local_err);
         qemu_opts_del(opts);
         return -1;
     }
diff --git a/vl.c b/vl.c
index 44656d8..f2f8093 100644
--- a/vl.c
+++ b/vl.c
@@ -2232,10 +2232,15 @@ static int device_help_func(QemuOpts *opts, void *opaque)
 static int device_init_func(QemuOpts *opts, void *opaque)
 {
     DeviceState *dev;
+    Error *local_err = NULL;
 
-    dev = qdev_device_add(opts);
-    if (!dev)
+    dev = qdev_device_add(opts, &local_err);
+    assert((dev == NULL) == error_is_set(&local_err));
+    if (!dev) {
+        qerror_report_err(local_err);
+        error_free(local_err);
         return -1;
+    }
     return 0;
 }
 
-- 
1.7.1