drm/virtio: rework resource creation workflow.

This patch moves the virtio_gpu_cmd_create_resource() call (which
notifies the host about the new resource created) into the
virtio_gpu_object_create() function.  That way we can call
virtio_gpu_cmd_create_resource() before ttm_bo_init(), so the host
already knows about the object when ttm initializes the object and calls
our driver callbacks.

Specifically the object is already created when the
virtio_gpu_ttm_tt_bind() callback invokes virtio_gpu_object_attach(),
so the extra virtio_gpu_object_attach() calls done after
virtio_gpu_object_create() are not needed any more.

The fence support for the create ioctl becomes a bit more tricky though.
The code moved into virtio_gpu_object_create() too.  We first submit the
(fenced) virtio_gpu_cmd_create_resource() command, then initialize the
ttm object, and finally attach just created object to the fence for the
command in case it didn't finish yet.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Noralf Trønnes <noralf@tronnes.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20190318113332.10900-6-kraxel@redhat.com

drivers/gpu/drm/virtio/virtgpu_drv.h

@@ -55,7 +55,9 @@ struct virtio_gpu_object_params {
 	uint32_t width;
 	uint32_t height;
 	unsigned long size;
+	bool dumb;
 	/* 3d */
+	bool virgl;
 	uint32_t target;
 	uint32_t bind;
 	uint32_t depth;
@@ -219,6 +221,9 @@ struct virtio_gpu_fpriv {
 /* virtio_ioctl.c */
 #define DRM_VIRTIO_NUM_IOCTLS 10
 extern struct drm_ioctl_desc virtio_gpu_ioctls[DRM_VIRTIO_NUM_IOCTLS];
+int virtio_gpu_object_list_validate(struct ww_acquire_ctx *ticket,
+				    struct list_head *head);
+void virtio_gpu_unref_list(struct list_head *head);
 
 /* virtio_kms.c */
 int virtio_gpu_init(struct drm_device *dev);
@@ -241,7 +246,8 @@ void virtio_gpu_gem_object_close(struct drm_gem_object *obj,
 				 struct drm_file *file);
 struct virtio_gpu_object*
 virtio_gpu_alloc_object(struct drm_device *dev,
-			struct virtio_gpu_object_params *params);
+			struct virtio_gpu_object_params *params,
+			struct virtio_gpu_fence *fence);
 int virtio_gpu_mode_dumb_create(struct drm_file *file_priv,
 				struct drm_device *dev,
 				struct drm_mode_create_dumb *args);
@@ -258,7 +264,8 @@ int virtio_gpu_alloc_vbufs(struct virtio_gpu_device *vgdev);
 void virtio_gpu_free_vbufs(struct virtio_gpu_device *vgdev);
 void virtio_gpu_cmd_create_resource(struct virtio_gpu_device *vgdev,
 				    struct virtio_gpu_object *bo,
-				    struct virtio_gpu_object_params *params);
+				    struct virtio_gpu_object_params *params,
+				    struct virtio_gpu_fence *fence);
 void virtio_gpu_cmd_unref_resource(struct virtio_gpu_device *vgdev,
 				   uint32_t resource_id);
 void virtio_gpu_cmd_transfer_to_host_2d(struct virtio_gpu_device *vgdev,
@@ -317,7 +324,8 @@ void virtio_gpu_cmd_transfer_to_host_3d(struct virtio_gpu_device *vgdev,
 void
 virtio_gpu_cmd_resource_create_3d(struct virtio_gpu_device *vgdev,
 				  struct virtio_gpu_object *bo,
-				  struct virtio_gpu_object_params *params);
+				  struct virtio_gpu_object_params *params,
+				  struct virtio_gpu_fence *fence);
 void virtio_gpu_ctrl_ack(struct virtqueue *vq);
 void virtio_gpu_cursor_ack(struct virtqueue *vq);
 void virtio_gpu_fence_ack(struct virtqueue *vq);
@@ -345,6 +353,7 @@ void virtio_gpu_ttm_fini(struct virtio_gpu_device *vgdev);
 int virtio_gpu_mmap(struct file *filp, struct vm_area_struct *vma);
 
 /* virtio_gpu_fence.c */
+bool virtio_fence_signaled(struct dma_fence *f);
 struct virtio_gpu_fence *virtio_gpu_fence_alloc(
 	struct virtio_gpu_device *vgdev);
 int virtio_gpu_fence_emit(struct virtio_gpu_device *vgdev,
@@ -356,7 +365,8 @@ void virtio_gpu_fence_event_process(struct virtio_gpu_device *vdev,
 /* virtio_gpu_object */
 int virtio_gpu_object_create(struct virtio_gpu_device *vgdev,
 			     struct virtio_gpu_object_params *params,
-			     struct virtio_gpu_object **bo_ptr);
+			     struct virtio_gpu_object **bo_ptr,
+			     struct virtio_gpu_fence *fence);
 void virtio_gpu_object_kunmap(struct virtio_gpu_object *bo);
 int virtio_gpu_object_kmap(struct virtio_gpu_object *bo);
 int virtio_gpu_object_get_sg_table(struct virtio_gpu_device *qdev,

drivers/gpu/drm/virtio/virtgpu_fence.c

@@ -36,7 +36,7 @@ static const char *virtio_get_timeline_name(struct dma_fence *f)
 	return "controlq";
 }
 
-static bool virtio_signaled(struct dma_fence *f)
+bool virtio_fence_signaled(struct dma_fence *f)
 {
 	struct virtio_gpu_fence *fence = to_virtio_fence(f);
 
@@ -62,7 +62,7 @@ static void virtio_timeline_value_str(struct dma_fence *f, char *str, int size)
 static const struct dma_fence_ops virtio_fence_ops = {
 	.get_driver_name     = virtio_get_driver_name,
 	.get_timeline_name   = virtio_get_timeline_name,
-	.signaled            = virtio_signaled,
+	.signaled            = virtio_fence_signaled,
 	.fence_value_str     = virtio_fence_value_str,
 	.timeline_value_str  = virtio_timeline_value_str,
 };

drivers/gpu/drm/virtio/virtgpu_gem.c

@@ -36,13 +36,14 @@ void virtio_gpu_gem_free_object(struct drm_gem_object *gem_obj)
 
 struct virtio_gpu_object*
 virtio_gpu_alloc_object(struct drm_device *dev,
-			struct virtio_gpu_object_params *params)
+			struct virtio_gpu_object_params *params,
+			struct virtio_gpu_fence *fence)
 {
 	struct virtio_gpu_device *vgdev = dev->dev_private;
 	struct virtio_gpu_object *obj;
 	int ret;
 
-	ret = virtio_gpu_object_create(vgdev, params, &obj);
+	ret = virtio_gpu_object_create(vgdev, params, &obj, fence);
 	if (ret)
 		return ERR_PTR(ret);
 
@@ -59,7 +60,7 @@ int virtio_gpu_gem_create(struct drm_file *file,
 	int ret;
 	u32 handle;
 
-	obj = virtio_gpu_alloc_object(dev, params);
+	obj = virtio_gpu_alloc_object(dev, params, NULL);
 	if (IS_ERR(obj))
 		return PTR_ERR(obj);
 
@@ -82,9 +83,7 @@ int virtio_gpu_mode_dumb_create(struct drm_file *file_priv,
 				struct drm_device *dev,
 				struct drm_mode_create_dumb *args)
 {
-	struct virtio_gpu_device *vgdev = dev->dev_private;
 	struct drm_gem_object *gobj;
-	struct virtio_gpu_object *obj;
 	struct virtio_gpu_object_params params = { 0 };
 	int ret;
 	uint32_t pitch;
@@ -100,20 +99,12 @@ int virtio_gpu_mode_dumb_create(struct drm_file *file_priv,
 	params.width = args->width;
 	params.height = args->height;
 	params.size = args->size;
+	params.dumb = true;
 	ret = virtio_gpu_gem_create(file_priv, dev, &params, &gobj,
 				    &args->handle);
 	if (ret)
 		goto fail;
 
-	obj = gem_to_virtio_gpu_obj(gobj);
-	virtio_gpu_cmd_create_resource(vgdev, obj, &params);
-
-	/* attach the object to the resource */
-	ret = virtio_gpu_object_attach(vgdev, obj, NULL);
-	if (ret)
-		goto fail;
-
-	obj->dumb = true;
 	args->pitch = pitch;
 	return ret;
 

drivers/gpu/drm/virtio/virtgpu_ioctl.c

@@ -54,8 +54,8 @@ static int virtio_gpu_map_ioctl(struct drm_device *dev, void *data,
 					 &virtio_gpu_map->offset);
 }
 
-static int virtio_gpu_object_list_validate(struct ww_acquire_ctx *ticket,
-					   struct list_head *head)
+int virtio_gpu_object_list_validate(struct ww_acquire_ctx *ticket,
+				    struct list_head *head)
 {
 	struct ttm_operation_ctx ctx = { false, false };
 	struct ttm_validate_buffer *buf;
@@ -79,7 +79,7 @@ static int virtio_gpu_object_list_validate(struct ww_acquire_ctx *ticket,
 	return 0;
 }
 
-static void virtio_gpu_unref_list(struct list_head *head)
+void virtio_gpu_unref_list(struct list_head *head)
 {
 	struct ttm_validate_buffer *buf;
 	struct ttm_buffer_object *bo;
@@ -275,14 +275,11 @@ static int virtio_gpu_resource_create_ioctl(struct drm_device *dev, void *data,
 {
 	struct virtio_gpu_device *vgdev = dev->dev_private;
 	struct drm_virtgpu_resource_create *rc = data;
+	struct virtio_gpu_fence *fence;
 	int ret;
 	struct virtio_gpu_object *qobj;
 	struct drm_gem_object *obj;
 	uint32_t handle = 0;
-	struct list_head validate_list;
-	struct ttm_validate_buffer mainbuf;
-	struct virtio_gpu_fence *fence = NULL;
-	struct ww_acquire_ctx ticket;
 	struct virtio_gpu_object_params params = { 0 };
 
 	if (vgdev->has_virgl_3d == false) {
@@ -298,14 +295,12 @@ static int virtio_gpu_resource_create_ioctl(struct drm_device *dev, void *data,
 			return -EINVAL;
 	}
 
-	INIT_LIST_HEAD(&validate_list);
-	memset(&mainbuf, 0, sizeof(struct ttm_validate_buffer));
-
 	params.format = rc->format;
 	params.width = rc->width;
 	params.height = rc->height;
 	params.size = rc->size;
 	if (vgdev->has_virgl_3d) {
+		params.virgl = true;
 		params.target = rc->target;
 		params.bind = rc->bind;
 		params.depth = rc->depth;
@@ -318,72 +313,25 @@ static int virtio_gpu_resource_create_ioctl(struct drm_device *dev, void *data,
 	if (params.size == 0)
 		params.size = PAGE_SIZE;
 
-	qobj = virtio_gpu_alloc_object(dev, &params);
+	fence = virtio_gpu_fence_alloc(vgdev);
+	if (!fence)
+		return -ENOMEM;
+	qobj = virtio_gpu_alloc_object(dev, &params, fence);
+	dma_fence_put(&fence->f);
 	if (IS_ERR(qobj))
 		return PTR_ERR(qobj);
 	obj = &qobj->gem_base;
 
-	if (!vgdev->has_virgl_3d) {
-		virtio_gpu_cmd_create_resource(vgdev, qobj, &params);
-
-		ret = virtio_gpu_object_attach(vgdev, qobj, NULL);
-	} else {
-		/* use a gem reference since unref list undoes them */
-		drm_gem_object_get(&qobj->gem_base);
-		mainbuf.bo = &qobj->tbo;
-		list_add(&mainbuf.head, &validate_list);
-
-		ret = virtio_gpu_object_list_validate(&ticket, &validate_list);
-		if (ret) {
-			DRM_DEBUG("failed to validate\n");
-			goto fail_unref;
-		}
-
-		fence = virtio_gpu_fence_alloc(vgdev);
-		if (!fence) {
-			ret = -ENOMEM;
-			goto fail_backoff;
-		}
-
-		virtio_gpu_cmd_resource_create_3d(vgdev, qobj, &params);
-		ret = virtio_gpu_object_attach(vgdev, qobj, fence);
-		if (ret) {
-			dma_fence_put(&fence->f);
-			goto fail_backoff;
-		}
-		ttm_eu_fence_buffer_objects(&ticket, &validate_list, &fence->f);
-	}
-
 	ret = drm_gem_handle_create(file_priv, obj, &handle);
 	if (ret) {
-
 		drm_gem_object_release(obj);
-		if (vgdev->has_virgl_3d) {
-			virtio_gpu_unref_list(&validate_list);
-			dma_fence_put(&fence->f);
-		}
 		return ret;
 	}
 	drm_gem_object_put_unlocked(obj);
 
 	rc->res_handle = qobj->hw_res_handle; /* similiar to a VM address */
 	rc->bo_handle = handle;
-
-	if (vgdev->has_virgl_3d) {
-		virtio_gpu_unref_list(&validate_list);
-		dma_fence_put(&fence->f);
-	}
 	return 0;
-fail_backoff:
-	ttm_eu_backoff_reservation(&ticket, &validate_list);
-fail_unref:
-	if (vgdev->has_virgl_3d) {
-		virtio_gpu_unref_list(&validate_list);
-		dma_fence_put(&fence->f);
-	}
-//fail_obj:
-//	drm_gem_object_handle_unreference_unlocked(obj);
-	return ret;
 }
 
 static int virtio_gpu_resource_info_ioctl(struct drm_device *dev, void *data,

drivers/gpu/drm/virtio/virtgpu_object.c

@@ -23,6 +23,8 @@
  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
 
+#include <drm/ttm/ttm_execbuf_util.h>
+
 #include "virtgpu_drv.h"
 
 static int virtio_gpu_resource_id_get(struct virtio_gpu_device *vgdev,
@@ -92,7 +94,8 @@ static void virtio_gpu_init_ttm_placement(struct virtio_gpu_object *vgbo)
 
 int virtio_gpu_object_create(struct virtio_gpu_device *vgdev,
 			     struct virtio_gpu_object_params *params,
-			     struct virtio_gpu_object **bo_ptr)
+			     struct virtio_gpu_object **bo_ptr,
+			     struct virtio_gpu_fence *fence)
 {
 	struct virtio_gpu_object *bo;
 	size_t acc_size;
@@ -118,9 +121,15 @@ int virtio_gpu_object_create(struct virtio_gpu_device *vgdev,
 		kfree(bo);
 		return ret;
 	}
-	bo->dumb = false;
-	virtio_gpu_init_ttm_placement(bo);
+	bo->dumb = params->dumb;
+
+	if (params->virgl) {
+		virtio_gpu_cmd_resource_create_3d(vgdev, bo, params, fence);
+	} else {
+		virtio_gpu_cmd_create_resource(vgdev, bo, params, fence);
+	}
 
+	virtio_gpu_init_ttm_placement(bo);
 	ret = ttm_bo_init(&vgdev->mman.bdev, &bo->tbo, params->size,
 			  ttm_bo_type_device, &bo->placement, 0,
 			  true, acc_size, NULL, NULL,
@@ -129,6 +138,38 @@ int virtio_gpu_object_create(struct virtio_gpu_device *vgdev,
 	if (ret != 0)
 		return ret;
 
+	if (fence) {
+		struct virtio_gpu_fence_driver *drv = &vgdev->fence_drv;
+		struct list_head validate_list;
+		struct ttm_validate_buffer mainbuf;
+		struct ww_acquire_ctx ticket;
+		unsigned long irq_flags;
+		bool signaled;
+
+		INIT_LIST_HEAD(&validate_list);
+		memset(&mainbuf, 0, sizeof(struct ttm_validate_buffer));
+
+		/* use a gem reference since unref list undoes them */
+		drm_gem_object_get(&bo->gem_base);
+		mainbuf.bo = &bo->tbo;
+		list_add(&mainbuf.head, &validate_list);
+
+		ret = virtio_gpu_object_list_validate(&ticket, &validate_list);
+		if (ret == 0) {
+			spin_lock_irqsave(&drv->lock, irq_flags);
+			signaled = virtio_fence_signaled(&fence->f);
+			if (!signaled)
+				/* virtio create command still in flight */
+				ttm_eu_fence_buffer_objects(&ticket, &validate_list,
+							    &fence->f);
+			spin_unlock_irqrestore(&drv->lock, irq_flags);
+			if (signaled)
+				/* virtio create command finished */
+				ttm_eu_backoff_reservation(&ticket, &validate_list);
+		}
+		virtio_gpu_unref_list(&validate_list);
+	}
+
 	*bo_ptr = bo;
 	return 0;
 }

drivers/gpu/drm/virtio/virtgpu_vq.c

@@ -376,7 +376,8 @@ static int virtio_gpu_queue_cursor(struct virtio_gpu_device *vgdev,
 /* create a basic resource */
 void virtio_gpu_cmd_create_resource(struct virtio_gpu_device *vgdev,
 				    struct virtio_gpu_object *bo,
-				    struct virtio_gpu_object_params *params)
+				    struct virtio_gpu_object_params *params,
+				    struct virtio_gpu_fence *fence)
 {
 	struct virtio_gpu_resource_create_2d *cmd_p;
 	struct virtio_gpu_vbuffer *vbuf;
@@ -390,7 +391,7 @@ void virtio_gpu_cmd_create_resource(struct virtio_gpu_device *vgdev,
 	cmd_p->width = cpu_to_le32(params->width);
 	cmd_p->height = cpu_to_le32(params->height);
 
-	virtio_gpu_queue_ctrl_buffer(vgdev, vbuf);
+	virtio_gpu_queue_fenced_ctrl_buffer(vgdev, vbuf, &cmd_p->hdr, fence);
 	bo->created = true;
 }
 
@@ -826,7 +827,8 @@ void virtio_gpu_cmd_context_detach_resource(struct virtio_gpu_device *vgdev,
 void
 virtio_gpu_cmd_resource_create_3d(struct virtio_gpu_device *vgdev,
 				  struct virtio_gpu_object *bo,
-				  struct virtio_gpu_object_params *params)
+				  struct virtio_gpu_object_params *params,
+				  struct virtio_gpu_fence *fence)
 {
 	struct virtio_gpu_resource_create_3d *cmd_p;
 	struct virtio_gpu_vbuffer *vbuf;
@@ -848,7 +850,7 @@ virtio_gpu_cmd_resource_create_3d(struct virtio_gpu_device *vgdev,
 	cmd_p->nr_samples = cpu_to_le32(params->nr_samples);
 	cmd_p->flags = cpu_to_le32(params->flags);
 
-	virtio_gpu_queue_ctrl_buffer(vgdev, vbuf);
+	virtio_gpu_queue_fenced_ctrl_buffer(vgdev, vbuf, &cmd_p->hdr, fence);
 	bo->created = true;
 }
 
@@ -932,8 +934,8 @@ int virtio_gpu_object_attach(struct virtio_gpu_device *vgdev,
 	struct scatterlist *sg;
 	int si, nents;
 
-	if (!obj->created)
-		return 0;
+	if (WARN_ON_ONCE(!obj->created))
+		return -EINVAL;
 
 	if (!obj->pages) {
 		int ret;