Linux Virtualization - Jun 2019 - [PATCH v2 08/12] drm/virtio: rework virtio_gpu_object_create fencing

Use gem reservation helpers and direct reservation_object_* calls
instead of ttm.

Signed-off-by: Gerd Hoffmann <kraxel at redhat.com>
---
 drivers/gpu/drm/virtio/virtgpu_object.c | 28 +++++++------------------
 1 file changed, 8 insertions(+), 20 deletions(-)

diff --git a/drivers/gpu/drm/virtio/virtgpu_object.c
b/drivers/gpu/drm/virtio/virtgpu_object.c
index 82bfbf983fd2..461f15f26517 100644
--- a/drivers/gpu/drm/virtio/virtgpu_object.c
+++ b/drivers/gpu/drm/virtio/virtgpu_object.c
@@ -141,34 +141,22 @@ int virtio_gpu_object_create(struct virtio_gpu_device
*vgdev,
 
 	if (fence) {
 		struct virtio_gpu_fence_driver *drv = &vgdev->fence_drv;
-		struct list_head validate_list;
-		struct ttm_validate_buffer mainbuf;
+		struct drm_gem_object *obj = &bo->gem_base;
 		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);
+		drm_gem_object_get(obj);
+		ret = drm_gem_lock_reservations(&obj, 1, &ticket);
 		if (ret == 0) {
 			spin_lock_irqsave(&drv->lock, irq_flags);
-			signaled = virtio_fence_signaled(&fence->f);
-			if (!signaled)
+			if (!virtio_fence_signaled(&fence->f))
 				/* virtio create command still in flight */
-				ttm_eu_fence_buffer_objects(&ticket, &validate_list,
-							    &fence->f);
+				reservation_object_add_excl_fence(obj->resv,
+								  &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);
+		drm_gem_unlock_reservations(&obj, 1, &ticket);
+		drm_gem_object_put_unlocked(obj);
 	}
 
 	*bo_ptr = bo;
-- 
2.18.1

On Tue, Jun 18, 2019 at 03:58:16PM +0200, Gerd Hoffmann
wrote:
> Use gem reservation helpers and direct reservation_object_* calls
> instead of ttm.
> 
> Signed-off-by: Gerd Hoffmann <kraxel at redhat.com>
> ---
>  drivers/gpu/drm/virtio/virtgpu_object.c | 28 +++++++------------------
>  1 file changed, 8 insertions(+), 20 deletions(-)
> 
> diff --git a/drivers/gpu/drm/virtio/virtgpu_object.c
b/drivers/gpu/drm/virtio/virtgpu_object.c
> index 82bfbf983fd2..461f15f26517 100644
> --- a/drivers/gpu/drm/virtio/virtgpu_object.c
> +++ b/drivers/gpu/drm/virtio/virtgpu_object.c
> @@ -141,34 +141,22 @@ int virtio_gpu_object_create(struct virtio_gpu_device
*vgdev,
>  
>  	if (fence) {
>  		struct virtio_gpu_fence_driver *drv = &vgdev->fence_drv;
> -		struct list_head validate_list;
> -		struct ttm_validate_buffer mainbuf;
> +		struct drm_gem_object *obj = &bo->gem_base;
>  		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);
> +		drm_gem_object_get(obj);
> +		ret = drm_gem_lock_reservations(&obj, 1, &ticket);
>  		if (ret == 0) {
>  			spin_lock_irqsave(&drv->lock, irq_flags);
> -			signaled = virtio_fence_signaled(&fence->f);
> -			if (!signaled)
> +			if (!virtio_fence_signaled(&fence->f))
>  				/* virtio create command still in flight */
> -				ttm_eu_fence_buffer_objects(&ticket, &validate_list,
> -							    &fence->f);
Same issue with the refcounting gone wrong here as in the previous patch.
-Daniel
> +				reservation_object_add_excl_fence(obj->resv,
> +								  &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);
> +		drm_gem_unlock_reservations(&obj, 1, &ticket);
> +		drm_gem_object_put_unlocked(obj);
>  	}
>  
>  	*bo_ptr = bo;
> -- 
> 2.18.1
> 
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch