Re: [PATCH rdma-next v3 1/1] RDMA/mana: Provide a modern CQ creation interface

[Leon Romanovsky <leon@kernel.org>]

On Wed, Mar 18, 2026 at 10:54:55AM -0700, Konstantin Taranov wrote:
> From: Konstantin Taranov <kotaranov@microsoft.com>
> 
> The uverbs CQ creation UAPI allows users to supply their own umem for a CQ.
> Create cq->umem if it was not created and use it to create a mana queue.
> The created umem is owned by IB/core and will be deallocated by IB/core.
> 
> To support RDMA objects that own umem, introduce mana_ib_create_queue_with_umem()
> to use the umem provided by the caller and do not de-allocate umem if it was allocted
> by the caller.
> 
> Signed-off-by: Konstantin Taranov <kotaranov@microsoft.com>
> ---
> v3: Make umem allocation explicit for cq->umem and use a new helper to create mana queue from it.
>     Remove the universal helper that was added in v2
> v2: Rework of Leon's commit. Introduce univesal helper that returned ownership of umem to caller.
>     Added removed u32 overlow check for kernel cq.
>  drivers/infiniband/hw/mana/cq.c      | 131 ++++++++++++++++++---------
>  drivers/infiniband/hw/mana/device.c  |   1 +
>  drivers/infiniband/hw/mana/main.c    |  27 +++---
>  drivers/infiniband/hw/mana/mana_ib.h |   5 +-
>  4 files changed, 106 insertions(+), 58 deletions(-)

<...>

> +int mana_ib_create_queue_from_umem(struct mana_ib_dev *mdev, struct ib_umem *umem,
> +				   struct mana_ib_queue *queue)
> +{
> +	queue->umem = NULL;

Two things. First, I'm waiting for Jason to converge on this  
ib_copy_*() work. Second, I still believe drivers should not cache  
umem.

Thanks