Add vhost-user-input-pci

Add a new virtio-input device, which connects to a vhost-user
backend.

Instead of reading configuration directly from an input device /
evdev (like virtio-input-host), it reads it over vhost-user protocol
with {SET,GET}_CONFIG messages. The vhost-user-backend handles the
queues & events setup.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-id: 20190503130034.24916-5-marcandre.lureau@redhat.com

[ kraxel: drop -{non-,}transitional variants ]
[ kraxel: fix "make check" on !linux ]

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

3 files changed, 135 insertions, 0 deletions

diff --git a/hw/input/Kconfig b/hw/input/Kconfig
index e2e66f0858..50e55e3538 100644
--- a/hw/input/Kconfig
+++ b/hw/input/Kconfig
@@ -29,5 +29,10 @@ config VIRTIO_INPUT_HOST
     default y
     depends on VIRTIO && LINUX
 
+config VHOST_USER_INPUT
+    bool
+    default y
+    depends on VIRTIO_INPUT && VHOST_USER
+
 config TSC210X
     bool
diff --git a/hw/input/Makefile.objs b/hw/input/Makefile.objs
index c8b00f71ec..3eddf00f2b 100644
--- a/hw/input/Makefile.objs
+++ b/hw/input/Makefile.objs
@@ -12,6 +12,7 @@ common-obj-$(CONFIG_VIRTIO_INPUT) += virtio-input-hid.o
 ifeq ($(CONFIG_LINUX),y)
 common-obj-$(CONFIG_VIRTIO_INPUT) += virtio-input-host.o
 endif
+common-obj-$(CONFIG_VHOST_USER_INPUT) += vhost-user-input.o
 
 obj-$(CONFIG_MILKYMIST) += milkymist-softusb.o
 obj-$(CONFIG_PXA2XX) += pxa2xx_keypad.o
diff --git a/hw/input/vhost-user-input.c b/hw/input/vhost-user-input.c
new file mode 100644
index 0000000000..6da497b1a8
--- /dev/null
+++ b/hw/input/vhost-user-input.c
@@ -0,0 +1,129 @@
+/*
+ * 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/qdev.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", &error_abort);
+}
+
+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)