qemu/hw/input/vhost-user-input.c
Markus Armbruster d2623129a7 qom: Drop parameter @errp of object_property_add() & friends
The only way object_property_add() can fail is when a property with
the same name already exists.  Since our property names are all
hardcoded, failure is a programming error, and the appropriate way to
handle it is passing &error_abort.

Same for its variants, except for object_property_add_child(), which
additionally fails when the child already has a parent.  Parentage is
also under program control, so this is a programming error, too.

We have a bit over 500 callers.  Almost half of them pass
&error_abort, slightly fewer ignore errors, one test case handles
errors, and the remaining few callers pass them to their own callers.

The previous few commits demonstrated once again that ignoring
programming errors is a bad idea.

Of the few ones that pass on errors, several violate the Error API.
The Error ** argument must be NULL, &error_abort, &error_fatal, or a
pointer to a variable containing NULL.  Passing an argument of the
latter kind twice without clearing it in between is wrong: if the
first call sets an error, it no longer points to NULL for the second
call.  ich9_pm_add_properties(), sparc32_ledma_realize(),
sparc32_dma_realize(), xilinx_axidma_realize(), xilinx_enet_realize()
are wrong that way.

When the one appropriate choice of argument is &error_abort, letting
users pick the argument is a bad idea.

Drop parameter @errp and assert the preconditions instead.

There's one exception to "duplicate property name is a programming
error": the way object_property_add() implements the magic (and
undocumented) "automatic arrayification".  Don't drop @errp there.
Instead, rename object_property_add() to object_property_try_add(),
and add the obvious wrapper object_property_add().

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200505152926.18877-15-armbru@redhat.com>
[Two semantic rebase conflicts resolved]
2020-05-15 07:07:58 +02:00

129 lines
3.5 KiB
C

/*
* This work is licensed under the terms of the GNU GPL, version 2 or
* (at your option) any later version. See the COPYING file in the
* top-level directory.
*/
#include "qemu/osdep.h"
#include "qemu/error-report.h"
#include "qapi/error.h"
#include "qemu-common.h"
#include "hw/virtio/virtio-input.h"
static int vhost_input_config_change(struct vhost_dev *dev)
{
error_report("vhost-user-input: unhandled backend config change");
return -1;
}
static const VhostDevConfigOps config_ops = {
.vhost_dev_config_notifier = vhost_input_config_change,
};
static void vhost_input_realize(DeviceState *dev, Error **errp)
{
VHostUserInput *vhi = VHOST_USER_INPUT(dev);
VirtIOInput *vinput = VIRTIO_INPUT(dev);
VirtIODevice *vdev = VIRTIO_DEVICE(dev);
vhost_dev_set_config_notifier(&vhi->vhost->dev, &config_ops);
vinput->cfg_size = sizeof_field(virtio_input_config, u);
if (vhost_user_backend_dev_init(vhi->vhost, vdev, 2, errp) == -1) {
return;
}
}
static void vhost_input_change_active(VirtIOInput *vinput)
{
VHostUserInput *vhi = VHOST_USER_INPUT(vinput);
if (vinput->active) {
vhost_user_backend_start(vhi->vhost);
} else {
vhost_user_backend_stop(vhi->vhost);
}
}
static void vhost_input_get_config(VirtIODevice *vdev, uint8_t *config_data)
{
VirtIOInput *vinput = VIRTIO_INPUT(vdev);
VHostUserInput *vhi = VHOST_USER_INPUT(vdev);
int ret;
memset(config_data, 0, vinput->cfg_size);
ret = vhost_dev_get_config(&vhi->vhost->dev, config_data, vinput->cfg_size);
if (ret) {
error_report("vhost-user-input: get device config space failed");
return;
}
}
static void vhost_input_set_config(VirtIODevice *vdev,
const uint8_t *config_data)
{
VHostUserInput *vhi = VHOST_USER_INPUT(vdev);
int ret;
ret = vhost_dev_set_config(&vhi->vhost->dev, config_data,
0, sizeof(virtio_input_config),
VHOST_SET_CONFIG_TYPE_MASTER);
if (ret) {
error_report("vhost-user-input: set device config space failed");
return;
}
virtio_notify_config(vdev);
}
static const VMStateDescription vmstate_vhost_input = {
.name = "vhost-user-input",
.unmigratable = 1,
};
static void vhost_input_class_init(ObjectClass *klass, void *data)
{
VirtIOInputClass *vic = VIRTIO_INPUT_CLASS(klass);
VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
DeviceClass *dc = DEVICE_CLASS(klass);
dc->vmsd = &vmstate_vhost_input;
vdc->get_config = vhost_input_get_config;
vdc->set_config = vhost_input_set_config;
vic->realize = vhost_input_realize;
vic->change_active = vhost_input_change_active;
}
static void vhost_input_init(Object *obj)
{
VHostUserInput *vhi = VHOST_USER_INPUT(obj);
vhi->vhost = VHOST_USER_BACKEND(object_new(TYPE_VHOST_USER_BACKEND));
object_property_add_alias(obj, "chardev",
OBJECT(vhi->vhost), "chardev");
}
static void vhost_input_finalize(Object *obj)
{
VHostUserInput *vhi = VHOST_USER_INPUT(obj);
object_unref(OBJECT(vhi->vhost));
}
static const TypeInfo vhost_input_info = {
.name = TYPE_VHOST_USER_INPUT,
.parent = TYPE_VIRTIO_INPUT,
.instance_size = sizeof(VHostUserInput),
.instance_init = vhost_input_init,
.instance_finalize = vhost_input_finalize,
.class_init = vhost_input_class_init,
};
static void vhost_input_register_types(void)
{
type_register_static(&vhost_input_info);
}
type_init(vhost_input_register_types)