Re: [PATCH v3 3/6] rust: gpuvm: add GpuVm::obtain()

[Boris Brezillon <boris.brezillon@collabora.com>]

On Wed, 21 Jan 2026 11:31:19 +0000
Alice Ryhl <aliceryhl@google.com> wrote:

> +/// A [`GpuVmBo`] object in the GEM list.
> +///
> +/// # Invariants
> +///
> +/// Points at a `drm_gpuvm_bo` that contains a valid `T::VmBoData` and is present in the gem list.
> +pub struct GpuVmBoResident<T: DriverGpuVm>(NonNull<GpuVmBo<T>>);

I find the name a bit confusing: BO residency is often used to refer to
memory backing the buffer object, and in this case, you can end up with
a GpuVmBoResident being returned for a BO that has been evicted (one
that's no longer resident).

> +
> +impl<T: DriverGpuVm> GpuVmBoResident<T> {
> +    /// Returns a raw pointer to underlying C value.
> +    #[inline]
> +    pub fn as_raw(&self) -> *mut bindings::drm_gpuvm_bo {
> +        // SAFETY: The pointer references a valid `drm_gpuvm_bo`.
> +        unsafe { (*self.0.as_ptr()).inner.get() }
> +    }
> +}