drm/virtio: Create Dumb BOs as guest Blobs (v3)

If support for Blob resources is available, then dumb BOs created
by the driver can be considered as guest Blobs.

v2: Don't skip transfer and flush commands as part of plane update
as the device may have created a shared mapping. (Gerd)

v3: Don't create dumb BOs as Guest blobs if Virgl is enabled. (Gurchetan)

Cc: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Vivek Kasireddy <vivek.kasireddy@intel.com>
Acked-by: Gurchetan Singh <gurchetansingh@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20210413052614.2486768-1-vivek.kasireddy@intel.comSigned-off-by: Gerd Hoffmann <kraxel@redhat.com>

drivers/gpu/drm/virtio/virtgpu_gem.c

@@ -64,6 +64,7 @@ int virtio_gpu_mode_dumb_create(struct drm_file *file_priv,
 {
 	struct drm_gem_object *gobj;
 	struct virtio_gpu_object_params params = { 0 };
+	struct virtio_gpu_device *vgdev = dev->dev_private;
 	int ret;
 	uint32_t pitch;
 
@@ -79,6 +80,13 @@ int virtio_gpu_mode_dumb_create(struct drm_file *file_priv,
 	params.height = args->height;
 	params.size = args->size;
 	params.dumb = true;
+
+	if (vgdev->has_resource_blob && !vgdev->has_virgl_3d) {
+		params.blob_mem = VIRTGPU_BLOB_MEM_GUEST;
+		params.blob_flags = VIRTGPU_BLOB_FLAG_USE_SHAREABLE;
+		params.blob = true;
+	}
+
 	ret = virtio_gpu_gem_create(file_priv, dev, &params, &gobj,
 				    &args->handle);
 	if (ret)

drivers/gpu/drm/virtio/virtgpu_object.c

@@ -254,6 +254,9 @@ int virtio_gpu_object_create(struct virtio_gpu_device *vgdev,
 	}
 
 	if (params->blob) {
+		if (params->blob_mem == VIRTGPU_BLOB_MEM_GUEST)
+			bo->guest_blob = true;
+
 		virtio_gpu_cmd_resource_create_blob(vgdev, bo, params,
 						    ents, nents);
 	} else if (params->virgl) {