Re: [PATCH rdma-next v2 3/5] RDMA/umem: Add pinned revocable dmabuf import interface

[Leon Romanovsky <leon@kernel.org>]

On Mon, Mar 02, 2026 at 12:15:37AM +0000, Jacob Moroni wrote:
> Added an interface for importing a pinned but revocable dmabuf.
> This interface can be used by drivers that are capable of revocation
> so that they can import dmabufs from exporters that may require it,
> such as VFIO.
> 
> This interface implements a two step process, where drivers will first
> call ib_umem_dmabuf_get_pinned_revocable_and_lock() which will pin and
> map the dmabuf (and provide a functional move_notify/invalidate_mappings
> callback), but will return with the lock still held so that the
> driver can then populate the callback via
> ib_umem_dmabuf_set_revoke_locked() without races from concurrent
> revocations. This scheme also allows for easier integration with drivers
> that may not have actually allocated their internal MR objects at the time
> of the get_pinned_revocable* call.
> 
> Signed-off-by: Jacob Moroni <jmoroni@google.com>
> ---
>  drivers/infiniband/core/umem_dmabuf.c | 61 +++++++++++++++++++++++++++
>  include/rdma/ib_umem.h                | 20 +++++++++
>  2 files changed, 81 insertions(+)

<...>

> +void ib_umem_dmabuf_set_revoke_locked(struct ib_umem_dmabuf *umem_dmabuf,
> +				      void (*revoke)(void *priv), void *priv)
> +{
> +	dma_resv_assert_held(umem_dmabuf->attach->dmabuf->resv);
> +
> +	umem_dmabuf->pinned_revoke = revoke;
> +	umem_dmabuf->pinned_revoke_priv = priv;

I don't think that you need special priv, you can use umem_dmabuf->private instead.
See reg_user_mr_dmabuf():
 1680         umem_dmabuf->private = mr;

Everything else looks reasonable to me.

Thanks