Re: [PATCH v1] drm/amdgpu: lock bo before calling amdgpu_vm_bo_update_shared

["Christian König" <christian.koenig@amd.com>]

On 10/28/25 14:09, Pierre-Eric Pelloux-Prayer wrote:
> BO's reservation object must be locked before using
> amdgpu_vm_bo_update_shared otherwise dma_resv_assert_held will
> complain in amdgpu_vm_update_shared.
> 
> Signed-off-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>

Reviewed-by: Christian König <christian.koenig@amd.com>

> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
> index ff98c87b2e0b..830412f04b6c 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
> @@ -81,13 +81,20 @@ static int amdgpu_dma_buf_attach(struct dma_buf *dmabuf,
>  	struct drm_gem_object *obj = dmabuf->priv;
>  	struct amdgpu_bo *bo = gem_to_amdgpu_bo(obj);
>  	struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
> +	int r;
>  
>  	if (!amdgpu_dmabuf_is_xgmi_accessible(attach_adev, bo) &&
>  	    pci_p2pdma_distance(adev->pdev, attach->dev, false) < 0)
>  		attach->peer2peer = false;
>  
> +	r = dma_resv_lock(bo->tbo.base.resv, NULL);
> +	if (r)
> +		return r;
> +
>  	amdgpu_vm_bo_update_shared(bo);
>  
> +	dma_resv_unlock(bo->tbo.base.resv);
> +
>  	return 0;
>  }
>