[Qemu-devel] [PATCH 4/6] Add vhost-user-input-pci

[Marc-André Lureau]

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 <address@hidden>
---
 include/hw/virtio/virtio-input.h |  14 ++++
 hw/input/vhost-user-input.c      | 129 +++++++++++++++++++++++++++++++
 hw/virtio/vhost-user-input-pci.c |  53 +++++++++++++
 MAINTAINERS                      |   1 +
 hw/input/Kconfig                 |   5 ++
 hw/input/Makefile.objs           |   1 +
 hw/virtio/Makefile.objs          |   1 +
 7 files changed, 204 insertions(+)
 create mode 100644 hw/input/vhost-user-input.c
 create mode 100644 hw/virtio/vhost-user-input-pci.c

diff --git a/include/hw/virtio/virtio-input.h b/include/hw/virtio/virtio-input.h
index 054c38836f..4fca03e796 100644
--- a/include/hw/virtio/virtio-input.h
+++ b/include/hw/virtio/virtio-input.h
@@ -2,6 +2,7 @@
 #define QEMU_VIRTIO_INPUT_H
 
 #include "ui/input.h"
+#include "sysemu/vhost-user-backend.h"
 
 /* ----------------------------------------------------------------- */
 /* virtio input protocol                                             */
@@ -42,11 +43,18 @@ typedef struct virtio_input_event virtio_input_event;
 #define VIRTIO_INPUT_HOST_GET_PARENT_CLASS(obj) \
         OBJECT_GET_PARENT_CLASS(obj, TYPE_VIRTIO_INPUT_HOST)
 
+#define TYPE_VHOST_USER_INPUT   "vhost-user-input"
+#define VHOST_USER_INPUT(obj)                              \
+    OBJECT_CHECK(VHostUserInput, (obj), TYPE_VHOST_USER_INPUT)
+#define VHOST_USER_INPUT_GET_PARENT_CLASS(obj)             \
+    OBJECT_GET_PARENT_CLASS(obj, TYPE_VHOST_USER_INPUT)
+
 typedef struct VirtIOInput VirtIOInput;
 typedef struct VirtIOInputClass VirtIOInputClass;
 typedef struct VirtIOInputConfig VirtIOInputConfig;
 typedef struct VirtIOInputHID VirtIOInputHID;
 typedef struct VirtIOInputHost VirtIOInputHost;
+typedef struct VHostUserInput VHostUserInput;
 
 struct VirtIOInputConfig {
     virtio_input_config               config;
@@ -98,6 +106,12 @@ struct VirtIOInputHost {
     int                               fd;
 };
 
+struct VHostUserInput {
+    VirtIOInput                       parent_obj;
+
+    VhostUserBackend                  *vhost;
+};
+
 void virtio_input_send(VirtIOInput *vinput, virtio_input_event *event);
 void virtio_input_init_config(VirtIOInput *vinput,
                               virtio_input_config *config);
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)
diff --git a/hw/virtio/vhost-user-input-pci.c b/hw/virtio/vhost-user-input-pci.c
new file mode 100644
index 0000000000..3d1b7a85fd
--- /dev/null
+++ b/hw/virtio/vhost-user-input-pci.c
@@ -0,0 +1,53 @@
+/*
+ * This work is licensed under the terms of the GNU LGPL, version 2 or
+ * later.  See the COPYING.LIB file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+
+#include "hw/virtio/virtio.h"
+#include "hw/virtio/virtio-input.h"
+#include "qapi/error.h"
+#include "qemu/error-report.h"
+#include "virtio-pci.h"
+
+typedef struct VHostUserInputPCI VHostUserInputPCI;
+
+#define TYPE_VHOST_USER_INPUT_PCI "vhost-user-input-pci-base"
+
+#define VHOST_USER_INPUT_PCI(obj) \
+    OBJECT_CHECK(VHostUserInputPCI, (obj), TYPE_VHOST_USER_INPUT_PCI)
+
+struct VHostUserInputPCI {
+    VirtIOPCIProxy parent_obj;
+    VHostUserInput vhi;
+};
+
+static void vhost_user_input_pci_instance_init(Object *obj)
+{
+    VHostUserInputPCI *dev = VHOST_USER_INPUT_PCI(obj);
+
+    virtio_instance_init_common(obj, &dev->vhi, sizeof(dev->vhi),
+                                TYPE_VHOST_USER_INPUT);
+
+    object_property_add_alias(obj, "chardev",
+                              OBJECT(&dev->vhi), "chardev",
+                              &error_abort);
+}
+
+static const VirtioPCIDeviceTypeInfo vhost_user_input_pci_info = {
+    .base_name = TYPE_VHOST_USER_INPUT_PCI,
+    .generic_name = "vhost-user-input-pci",
+    .transitional_name = "vhost-user-input-pci-transitional",
+    .non_transitional_name = "vhost-user-input-pci-non-transitional",
+    .parent = TYPE_VIRTIO_INPUT_PCI,
+    .instance_size = sizeof(VHostUserInputPCI),
+    .instance_init = vhost_user_input_pci_instance_init,
+};
+
+static void vhost_user_input_pci_register(void)
+{
+    virtio_pci_types_register(&vhost_user_input_pci_info);
+}
+
+type_init(vhost_user_input_pci_register)
diff --git a/MAINTAINERS b/MAINTAINERS
index c48f13f877..075858968c 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1512,6 +1512,7 @@ L: address@hidden
 virtio-input
 M: Gerd Hoffmann <address@hidden>
 S: Maintained
+F: hw/input/vhost-user-input.c
 F: hw/input/virtio-input*.c
 F: include/hw/virtio/virtio-input.h
 
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..9511e3102f 100644
--- a/hw/input/Makefile.objs
+++ b/hw/input/Makefile.objs
@@ -11,6 +11,7 @@ common-obj-$(CONFIG_VIRTIO_INPUT) += virtio-input.o
 common-obj-$(CONFIG_VIRTIO_INPUT) += virtio-input-hid.o
 ifeq ($(CONFIG_LINUX),y)
 common-obj-$(CONFIG_VIRTIO_INPUT) += virtio-input-host.o
+common-obj-$(CONFIG_VHOST_USER_INPUT) += vhost-user-input.o
 endif
 
 obj-$(CONFIG_MILKYMIST) += milkymist-softusb.o
diff --git a/hw/virtio/Makefile.objs b/hw/virtio/Makefile.objs
index f2ab667a21..5570ea8df8 100644
--- a/hw/virtio/Makefile.objs
+++ b/hw/virtio/Makefile.objs
@@ -17,6 +17,7 @@ obj-$(CONFIG_VHOST_VSOCK) += vhost-vsock.o
 ifeq ($(CONFIG_VIRTIO_PCI),y)
 obj-$(CONFIG_VHOST_VSOCK) += vhost-vsock-pci.o
 obj-$(CONFIG_VHOST_USER_BLK) += vhost-user-blk-pci.o
+obj-$(CONFIG_VHOST_USER_INPUT) += vhost-user-input-pci.o
 obj-$(CONFIG_VHOST_USER_SCSI) += vhost-user-scsi-pci.o
 obj-$(CONFIG_VHOST_SCSI) += vhost-scsi-pci.o
 obj-$(CONFIG_VIRTIO_INPUT_HOST) += virtio-input-host-pci.o
-- 
2.21.0.313.ge35b8cb8e2