Re: [PATCH v2 2/2] drm/xe: add kernel VM BO unbind helper

[Matthew Brost <matthew.brost@intel.com>]

On Mon, Jan 19, 2026 at 05:03:30PM +0200, Farah Kassabri wrote:
> Add xe_kernel_vm_unbind_bo() as the counterpart to
> xe_kernel_vm_bind_bo() to provide symmetry in the kernel VM BO
> lifecycle.
> 
> The new helper allows explicit unbinding of buffer objects from
> the kernel VM, enabling proper cleanup and preventing stale
> kernel VM mappings when BOs are no longer needed.
> 
> Signed-off-by: Farah Kassabri <farah.kassabri@intel.com>
> Reviewed-by: Ilia Levi <ilia.levi@intel.com>
> 
> Changes in v2:
> pass cache_lvl argument to the map operation instead of 0.
> ---
>  drivers/gpu/drm/xe/xe_vm.c | 59 ++++++++++++++++++++++++++++++++------
>  drivers/gpu/drm/xe/xe_vm.h |  3 ++
>  2 files changed, 54 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_vm.c b/drivers/gpu/drm/xe/xe_vm.c
> index a27145a4137e..425f406712b8 100644
> --- a/drivers/gpu/drm/xe/xe_vm.c
> +++ b/drivers/gpu/drm/xe/xe_vm.c
> @@ -3830,21 +3830,22 @@ int xe_vm_bind_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
>  }
>  
>  /**
> - * xe_vm_kernel_bind_bo - bind a BO to a kernel owned VM
> + *  __xe_kernel_vm_bind_bo - internal helper to bind/unbind a BO to/from kernel owned VM
>   * @vm: VM to bind the BO to
>   * @bo: BO to bind
>   * @q: exec queue to use for the bind (optional)
>   * @addr: address at which to bind the BO
>   * @cache_lvl: PAT cache level to use
> + * @do_bind: true for bind, false for unbind
>   *
> - * Execute a VM bind map operation on a BO to bind it into a kernel-owned VM.
> + * Common code for binding and un-binding a BO.
>   *
>   * Returns a dma_fence to track the binding completion if the job to do so was
>   * successfully submitted, an error pointer otherwise.
>   */
> -struct dma_fence *xe_vm_kernel_bind_bo(struct xe_vm *vm, struct xe_bo *bo,
> -				       struct xe_exec_queue *q, u64 addr,
> -				       enum xe_cache_level cache_lvl)
> +static struct dma_fence *__xe_kernel_vm_bind_bo(struct xe_vm *vm, struct xe_bo *bo,
> +						struct xe_exec_queue *q, u64 addr,
> +						enum xe_cache_level cache_lvl, bool do_bind)
>  {
>  	struct xe_vma_ops vops;
>  	struct drm_gpuva_ops *ops = NULL;
> @@ -3860,9 +3861,13 @@ struct dma_fence *xe_vm_kernel_bind_bo(struct xe_vm *vm, struct xe_bo *bo,
>  
>  	xe_vma_ops_init(&vops, vm, q, NULL, 0);
>  
> -	ops = vm_bind_ioctl_ops_create(vm, &vops, bo, 0, addr, xe_bo_size(bo),
> -				       DRM_XE_VM_BIND_OP_MAP, 0, 0,
> -				       vm->xe->pat.idx[cache_lvl]);
> +	if (do_bind)
> +		ops = vm_bind_ioctl_ops_create(vm, &vops, bo, 0, addr, xe_bo_size(bo),
> +					       DRM_XE_VM_BIND_OP_MAP, 0, 0,
> +					       vm->xe->pat.idx[cache_lvl]);
> +	else
> +		ops = vm_bind_ioctl_ops_create(vm, &vops, bo, 0, addr, xe_bo_size(bo),
> +					       DRM_XE_VM_BIND_OP_UNMAP, 0, 0, 0);
>  	if (IS_ERR(ops)) {
>  		err = PTR_ERR(ops);
>  		goto release_vm_lock;
> @@ -3903,6 +3908,44 @@ struct dma_fence *xe_vm_kernel_bind_bo(struct xe_vm *vm, struct xe_bo *bo,
>  	return fence;
>  }
>  
> +/**
> + * xe_vm_kernel_bind_bo - bind a BO to a kernel owned VM
> + * @vm: VM to bind the BO to
> + * @bo: BO to bind
> + * @q: exec queue to use for the bind (optional)
> + * @addr: address at which to bind the BO
> + * @cache_lvl: PAT cache level to use
> + *
> + * Execute a VM bind map operation on a BO to bind it into a kernel-owned VM.
> + *
> + * Returns a dma_fence to track the binding completion if the job to do so was
> + * successfully submitted, an error pointer otherwise.
> + */
> +struct dma_fence *xe_vm_kernel_bind_bo(struct xe_vm *vm, struct xe_bo *bo,
> +				       struct xe_exec_queue *q, u64 addr,
> +				       enum xe_cache_level cache_lvl)
> +{
> +	return __xe_kernel_vm_bind_bo(vm, bo, q, addr, cache_lvl, true);
> +}
> +
> +/**
> + * xe_vm_kernel_unbind_bo - unbind a BO from a kernel owned VM
> + * @vm: VM to unbind the BO from
> + * @bo: BO to unbind
> + * @q: exec queue to use for the unbind (optional)
> + * @addr: address at which the BO was bound
> + *
> + * Execute a VM bind unmap operation on a BO to remove it from a kernel-owned VM.
> + *
> + * Returns a dma_fence to track the unbinding completion if the job to do so was
> + * successfully submitted, an error pointer otherwise.
> + */
> +struct dma_fence *xe_vm_kernel_unbind_bo(struct xe_vm *vm, struct xe_bo *bo,
> +					 struct xe_exec_queue *q, u64 addr)
> +{
> +	return __xe_kernel_vm_bind_bo(vm, bo, q, addr, 0, false);
> +}
> +
>  /**
>   * xe_vm_lock() - Lock the vm's dma_resv object
>   * @vm: The struct xe_vm whose lock is to be locked
> diff --git a/drivers/gpu/drm/xe/xe_vm.h b/drivers/gpu/drm/xe/xe_vm.h
> index ff32f43aa1d8..b87e80227c79 100644
> --- a/drivers/gpu/drm/xe/xe_vm.h
> +++ b/drivers/gpu/drm/xe/xe_vm.h
> @@ -272,6 +272,9 @@ struct dma_fence *xe_vm_kernel_bind_bo(struct xe_vm *vm, struct xe_bo *bo,
>  				       struct xe_exec_queue *q, u64 addr,
>  				       enum xe_cache_level cache_lvl);
>  
> +struct dma_fence *xe_vm_kernel_unbind_bo(struct xe_vm *vm, struct xe_bo *bo,
> +					 struct xe_exec_queue *q, u64 addr);
> +
>  void xe_vm_resume_rebind_worker(struct xe_vm *vm);
>  
>  /**
> -- 
> 2.43.0
> 
> ---------------------------------------------------------------------
> Intel Israel (74) Limited
> 

You should remove your footer for public mailing list posts.

But patch LGTM.
Reviewed-by: Matthew Brost <matthew.brost@intel.com>

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