virtio-gpu-pci: add virtio pci support

This patch adds virtio-gpu-pci, which is the pci proxy for the virtio
gpu device.  With this patch in place virtio-gpu is functional.  You
need a linux guest with a virtio-gpu driver though, and output will
appear pretty late in boot, once the kernel initialized drm and fbcon.

Written by Dave Airlie and Gerd Hoffmann.

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

hw/display/Makefile.objs

@@ -36,3 +36,4 @@ obj-$(CONFIG_VGA) += vga.o
 common-obj-$(CONFIG_QXL) += qxl.o qxl-logger.o qxl-render.o
 
 obj-$(CONFIG_VIRTIO) += virtio-gpu.o
+obj-$(CONFIG_VIRTIO_PCI) += virtio-gpu-pci.o

hw/display/virtio-gpu-pci.c

@@ -0,0 +1,68 @@
+/*
+ * Virtio video device
+ *
+ * Copyright Red Hat
+ *
+ * Authors:
+ *  Dave Airlie
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the COPYING file in the top-level directory.
+ *
+ */
+#include "hw/pci/pci.h"
+#include "hw/virtio/virtio.h"
+#include "hw/virtio/virtio-bus.h"
+#include "hw/virtio/virtio-pci.h"
+#include "hw/virtio/virtio-gpu.h"
+
+static Property virtio_gpu_pci_properties[] = {
+    DEFINE_VIRTIO_GPU_PROPERTIES(VirtIOGPUPCI, vdev.conf),
+    DEFINE_VIRTIO_GPU_PCI_PROPERTIES(VirtIOPCIProxy),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void virtio_gpu_pci_realize(VirtIOPCIProxy *vpci_dev, Error **errp)
+{
+    VirtIOGPUPCI *vgpu = VIRTIO_GPU_PCI(vpci_dev);
+    DeviceState *vdev = DEVICE(&vgpu->vdev);
+
+    qdev_set_parent_bus(vdev, BUS(&vpci_dev->bus));
+    /* force virtio-1.0 */
+    vpci_dev->flags &= ~VIRTIO_PCI_FLAG_DISABLE_MODERN;
+    vpci_dev->flags |= VIRTIO_PCI_FLAG_DISABLE_LEGACY;
+    object_property_set_bool(OBJECT(vdev), true, "realized", errp);
+}
+
+static void virtio_gpu_pci_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    VirtioPCIClass *k = VIRTIO_PCI_CLASS(klass);
+    PCIDeviceClass *pcidev_k = PCI_DEVICE_CLASS(klass);
+
+    set_bit(DEVICE_CATEGORY_DISPLAY, dc->categories);
+    dc->props = virtio_gpu_pci_properties;
+    k->realize = virtio_gpu_pci_realize;
+    pcidev_k->class_id = PCI_CLASS_DISPLAY_OTHER;
+}
+
+static void virtio_gpu_initfn(Object *obj)
+{
+    VirtIOGPUPCI *dev = VIRTIO_GPU_PCI(obj);
+    object_initialize(&dev->vdev, sizeof(dev->vdev), TYPE_VIRTIO_GPU);
+    object_property_add_child(obj, "virtio-backend", OBJECT(&dev->vdev), NULL);
+}
+
+static const TypeInfo virtio_gpu_pci_info = {
+    .name = TYPE_VIRTIO_GPU_PCI,
+    .parent = TYPE_VIRTIO_PCI,
+    .instance_size = sizeof(VirtIOGPUPCI),
+    .instance_init = virtio_gpu_initfn,
+    .class_init = virtio_gpu_pci_class_init,
+};
+
+static void virtio_gpu_pci_register_types(void)
+{
+    type_register_static(&virtio_gpu_pci_info);
+}
+type_init(virtio_gpu_pci_register_types)

hw/virtio/virtio-pci.h

@@ -25,6 +25,7 @@
 #include "hw/virtio/virtio-bus.h"
 #include "hw/virtio/virtio-9p.h"
 #include "hw/virtio/virtio-input.h"
+#include "hw/virtio/virtio-gpu.h"
 #ifdef CONFIG_VIRTFS
 #include "hw/9pfs/virtio-9p.h"
 #endif
@@ -42,6 +43,7 @@ typedef struct VHostSCSIPCI VHostSCSIPCI;
 typedef struct VirtIORngPCI VirtIORngPCI;
 typedef struct VirtIOInputPCI VirtIOInputPCI;
 typedef struct VirtIOInputHIDPCI VirtIOInputHIDPCI;
+typedef struct VirtIOGPUPCI VirtIOGPUPCI;
 
 /* virtio-pci-bus */
 
@@ -261,6 +263,18 @@ struct VirtIOInputHIDPCI {
     VirtIOInputHID vdev;
 };
 
+/*
+ * virtio-gpu-pci: This extends VirtioPCIProxy.
+ */
+#define TYPE_VIRTIO_GPU_PCI "virtio-gpu-pci"
+#define VIRTIO_GPU_PCI(obj) \
+        OBJECT_CHECK(VirtIOGPUPCI, (obj), TYPE_VIRTIO_GPU_PCI)
+
+struct VirtIOGPUPCI {
+    VirtIOPCIProxy parent_obj;
+    VirtIOGPU vdev;
+};
+
 /* Virtio ABI version, if we increment this, we break the guest driver. */
 #define VIRTIO_PCI_ABI_VERSION          0