# Re: \[PATCH rdma-next 04/15\] RDMA/core: Allow optional access flags in reg mr ioctl

- From: Jason Gunthorpe \<jgg@nvidia.com\>
- Date: 2026-08-11 19:32:09 
- List: netdev
- Page: https://ratatoskr.run/netdev/2026/08/17398579
- Thread: https://ratatoskr.run/linux-rdma/2026/07/17320154/t.md

```text
On Sun, 26 Jul 2026 12:29:18 +0300, Michael Gur [ref] wrote:
> The uverbs ABI reserves the optional access flags range as best-effort:
> drivers should accept any flag in this range and treat the actual support
> as opportunistic, never failing registration when an optional flag is
> requested.
> 
> Add the optional access flag to the allow-list of dmabuf registration
> through the reg_mr ioctl. Uverbs users can now request any optional access
> flag on dmabuf registrations and mlx5 will apply the flag's effect on a
> best-effort basis when supported.
> 
> [...]

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>

-- 
Jason
```