Re: [PATCH rdma-next v4 08/16] RDMA/efa: Use ib_umem_get_cq_buf() for user CQ buffer

[Leon Romanovsky <leon@kernel.org>]

On Thu, May 07, 2026 at 02:52:23PM +0200, Jiri Pirko wrote:
> From: Jiri Pirko <jiri@nvidia.com>
> 
> Pin the user CQ buffer with ib_umem_get_cq_buf() and take
> ownership of the umem in the driver. Fall back to the
> existing kernel-DMA path on NULL.
> 
> Signed-off-by: Jiri Pirko <jiri@nvidia.com>
> ---
> v2->v3:
> - used ib_umem_get_cq_buf() to get umem, stored in efa_cq->umem
> - replaced ib_umem_release_non_listed() with ib_umem_release()
> - added release to efa_destroy_cq() and new error path
> ---
>  drivers/infiniband/hw/efa/efa_verbs.c | 27 +++++++++++++++++----------
>  1 file changed, 17 insertions(+), 10 deletions(-)

<...>

> -	if (ibcq->umem) {
> -		if (ibcq->umem->length < cq->size) {
> -			ibdev_dbg(&dev->ibdev, "External memory too small\n");
> -			err = -EINVAL;
> -			goto err_out;
> -		}
> +	umem = ib_umem_get_cq_buf(ibcq->device, udata, cq->size,
> +				  IB_ACCESS_LOCAL_WRITE);
> +	if (IS_ERR(umem)) {
> +		err = PTR_ERR(umem);
> +		goto err_out;
> +	}
> +
> +	cq->umem = umem;
>  
> -		if (!ib_umem_is_contiguous(ibcq->umem)) {
> +	if (umem) {
> +		if (!ib_umem_is_contiguous(umem)) {
>  			ibdev_dbg(&dev->ibdev, "Non contiguous CQ unsupported\n");
>  			err = -EINVAL;
> -			goto err_out;
> +			goto err_release_umem;
>  		}
>  
> -		cq->dma_addr = ib_umem_start_dma_addr(ibcq->umem);
> +		cq->dma_addr = ib_umem_start_dma_addr(umem);

This patch is the one that confused me the most. Didn't we already set
`ibcq->umem` before calling ops.create_user_cq()? If so, we're now ignoring
that pointer.

Thanks