hw/virtio: rename vhost-user-device and make user creatable

We didn't make the device user creatable in the first place because we
were worried users might get confused. Rename the device to make its
nature as a test device even more explicit. While we are at it add a
Kconfig variable so it can be skipped for those that want to thin out
their build configuration even further.

Acked-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-ID: <20250820195632.1956795-1-alex.bennee@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Message-ID: <20250901105948.982583-1-alex.bennee@linaro.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

6 files changed, 26 insertions, 32 deletions

diff --git a/docs/system/devices/vhost-user.rst b/docs/system/devices/vhost-user.rst
index 35259d8ec7..bddf8df5ed 100644
--- a/docs/system/devices/vhost-user.rst
+++ b/docs/system/devices/vhost-user.rst
@@ -62,26 +62,20 @@ platform details for what sort of virtio bus to use.
 The referenced *daemons* are not exhaustive, any conforming backend
 implementing the device and using the vhost-user protocol should work.
 
-vhost-user-device
-^^^^^^^^^^^^^^^^^
+vhost-user-test-device
+^^^^^^^^^^^^^^^^^^^^^^
 
-The vhost-user-device is a generic development device intended for
-expert use while developing new backends. The user needs to specify
-all the required parameters including:
+The vhost-user-test-device is a generic development device intended
+for expert use while developing new backends. The user needs to
+specify all the required parameters including:
 
   - Device ``virtio-id``
   - The ``num_vqs`` it needs and their ``vq_size``
   - The ``config_size`` if needed
 
 .. note::
-  To prevent user confusion you cannot currently instantiate
-  vhost-user-device without first patching out::
-
-    /* Reason: stop inexperienced users confusing themselves */
-    dc->user_creatable = false;
-
-  in ``vhost-user-device.c`` and ``vhost-user-device-pci.c`` file and
-  rebuilding.
+  While this is a useful device for development it is not recommended
+  for production use.
 
 vhost-user daemon
 =================
diff --git a/hw/virtio/Kconfig b/hw/virtio/Kconfig
index 7648a2d68d..10f5c53ac0 100644
--- a/hw/virtio/Kconfig
+++ b/hw/virtio/Kconfig
@@ -126,3 +126,8 @@ config VHOST_USER_SCMI
     bool
     default y
     depends on VIRTIO && VHOST_USER && ARM
+
+config VHOST_USER_TEST
+    bool
+    default y
+    depends on VIRTIO && VHOST_USER
diff --git a/hw/virtio/meson.build b/hw/virtio/meson.build
index 3ea7b3cec8..48b9fedfa5 100644
--- a/hw/virtio/meson.build
+++ b/hw/virtio/meson.build
@@ -22,7 +22,7 @@ if have_vhost
     system_virtio_ss.add(files('vhost-user-base.c'))
 
     # MMIO Stubs
-    system_virtio_ss.add(files('vhost-user-device.c'))
+    system_virtio_ss.add(when: 'CONFIG_VHOST_USER_TEST', if_true: files('vhost-user-test-device.c'))
     system_virtio_ss.add(when: 'CONFIG_VHOST_USER_GPIO', if_true: files('vhost-user-gpio.c'))
     system_virtio_ss.add(when: 'CONFIG_VHOST_USER_I2C', if_true: files('vhost-user-i2c.c'))
     system_virtio_ss.add(when: 'CONFIG_VHOST_USER_RNG', if_true: files('vhost-user-rng.c'))
@@ -30,7 +30,8 @@ if have_vhost
     system_virtio_ss.add(when: 'CONFIG_VHOST_USER_INPUT', if_true: files('vhost-user-input.c'))
 
     # PCI Stubs
-    system_virtio_ss.add(when: 'CONFIG_VIRTIO_PCI', if_true: files('vhost-user-device-pci.c'))
+    system_virtio_ss.add(when: ['CONFIG_VIRTIO_PCI', 'CONFIG_VHOST_USER_TEST'],
+                         if_true: files('vhost-user-test-device-pci.c'))
     system_virtio_ss.add(when: ['CONFIG_VIRTIO_PCI', 'CONFIG_VHOST_USER_GPIO'],
                          if_true: files('vhost-user-gpio-pci.c'))
     system_virtio_ss.add(when: ['CONFIG_VIRTIO_PCI', 'CONFIG_VHOST_USER_I2C'],
diff --git a/hw/virtio/vhost-user-device-pci.c b/hw/virtio/vhost-user-test-device-pci.c
index f10bac874e..b4ed0efb50 100644
--- a/hw/virtio/vhost-user-device-pci.c
+++ b/hw/virtio/vhost-user-test-device-pci.c
@@ -18,13 +18,13 @@ struct VHostUserDevicePCI {
     VHostUserBase vub;
 };
 
-#define TYPE_VHOST_USER_DEVICE_PCI "vhost-user-device-pci-base"
+#define TYPE_VHOST_USER_TEST_DEVICE_PCI "vhost-user-test-device-pci-base"
 
-OBJECT_DECLARE_SIMPLE_TYPE(VHostUserDevicePCI, VHOST_USER_DEVICE_PCI)
+OBJECT_DECLARE_SIMPLE_TYPE(VHostUserDevicePCI, VHOST_USER_TEST_DEVICE_PCI)
 
 static void vhost_user_device_pci_realize(VirtIOPCIProxy *vpci_dev, Error **errp)
 {
-    VHostUserDevicePCI *dev = VHOST_USER_DEVICE_PCI(vpci_dev);
+    VHostUserDevicePCI *dev = VHOST_USER_TEST_DEVICE_PCI(vpci_dev);
     DeviceState *vdev = DEVICE(&dev->vub);
 
     vpci_dev->nvectors = 1;
@@ -38,9 +38,6 @@ static void vhost_user_device_pci_class_init(ObjectClass *klass,
     VirtioPCIClass *k = VIRTIO_PCI_CLASS(klass);
     PCIDeviceClass *pcidev_k = PCI_DEVICE_CLASS(klass);
 
-    /* Reason: stop users confusing themselves */
-    dc->user_creatable = false;
-
     k->realize = vhost_user_device_pci_realize;
     set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
     pcidev_k->vendor_id = PCI_VENDOR_ID_REDHAT_QUMRANET;
@@ -51,15 +48,15 @@ static void vhost_user_device_pci_class_init(ObjectClass *klass,
 
 static void vhost_user_device_pci_instance_init(Object *obj)
 {
-    VHostUserDevicePCI *dev = VHOST_USER_DEVICE_PCI(obj);
+    VHostUserDevicePCI *dev = VHOST_USER_TEST_DEVICE_PCI(obj);
 
     virtio_instance_init_common(obj, &dev->vub, sizeof(dev->vub),
-                                TYPE_VHOST_USER_DEVICE);
+                                TYPE_VHOST_USER_TEST_DEVICE);
 }
 
 static const VirtioPCIDeviceTypeInfo vhost_user_device_pci_info = {
-    .base_name = TYPE_VHOST_USER_DEVICE_PCI,
-    .non_transitional_name = "vhost-user-device-pci",
+    .base_name = TYPE_VHOST_USER_TEST_DEVICE_PCI,
+    .non_transitional_name = "vhost-user-test-device-pci",
     .instance_size = sizeof(VHostUserDevicePCI),
     .instance_init = vhost_user_device_pci_instance_init,
     .class_init = vhost_user_device_pci_class_init,
diff --git a/hw/virtio/vhost-user-device.c b/hw/virtio/vhost-user-test-device.c
index 3939bdf755..1b98ea3e48 100644
--- a/hw/virtio/vhost-user-device.c
+++ b/hw/virtio/vhost-user-test-device.c
@@ -1,5 +1,5 @@
 /*
- * Generic vhost-user-device implementation for any vhost-user-backend
+ * Generic vhost-user-test-device implementation for any vhost-user-backend
  *
  * This is a concrete implementation of vhost-user-base which can be
  * configured via properties. It is useful for development and
@@ -25,7 +25,7 @@
  */
 
 static const VMStateDescription vud_vmstate = {
-    .name = "vhost-user-device",
+    .name = "vhost-user-test-device",
     .unmigratable = 1,
 };
 
@@ -41,16 +41,13 @@ static void vud_class_init(ObjectClass *klass, const void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
 
-    /* Reason: stop inexperienced users confusing themselves */
-    dc->user_creatable = false;
-
     device_class_set_props(dc, vud_properties);
     dc->vmsd = &vud_vmstate;
     set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
 }
 
 static const TypeInfo vud_info = {
-    .name = TYPE_VHOST_USER_DEVICE,
+    .name = TYPE_VHOST_USER_TEST_DEVICE,
     .parent = TYPE_VHOST_USER_BASE,
     .class_init = vud_class_init,
 };
diff --git a/include/hw/virtio/vhost-user-base.h b/include/hw/virtio/vhost-user-base.h
index 51d0968b89..387e434b80 100644
--- a/include/hw/virtio/vhost-user-base.h
+++ b/include/hw/virtio/vhost-user-base.h
@@ -44,6 +44,6 @@ struct VHostUserBaseClass {
 };
 
 
-#define TYPE_VHOST_USER_DEVICE "vhost-user-device"
+#define TYPE_VHOST_USER_TEST_DEVICE "vhost-user-test-device"
 
 #endif /* QEMU_VHOST_USER_BASE_H */