Re: [PATCH v3 0/8] RDMA: Enable operation with DMA debug enabled

[Leon Romanovsky <leon@kernel.org>]

On Mon, Mar 16, 2026 at 09:06:44PM +0200, Leon Romanovsky wrote:
> Add a new DMA_ATTR_REQUIRE_COHERENT attribute to the DMA API to mark
> mappings that must run on a DMA‑coherent system. Such buffers cannot
> use the SWIOTLB path, may overlap with CPU caches, and do not depend on
> explicit cache flushing.
> 
> Mappings using this attribute are rejected on systems where cache
> side‑effects could lead to data corruption, and therefore do not need
> the cache‑overlap debugging logic. This series also includes fixes for
> DMA_ATTR_CPU_CACHE_CLEAN handling.
> Thanks.

<...>

> ---
> Leon Romanovsky (8):
>       dma-debug: Allow multiple invocations of overlapping entries
>       dma-mapping: handle DMA_ATTR_CPU_CACHE_CLEAN in trace output
>       dma-mapping: Clarify valid conditions for CPU cache line overlap
>       dma-mapping: Introduce DMA require coherency attribute
>       dma-direct: prevent SWIOTLB path when DMA_ATTR_REQUIRE_COHERENT is set
>       iommu/dma: add support for DMA_ATTR_REQUIRE_COHERENT attribute
>       RDMA/umem: Tell DMA mapping that UMEM requires coherency
>       mm/hmm: Indicate that HMM requires DMA coherency
> 
>  Documentation/core-api/dma-attributes.rst | 38 ++++++++++++++++++++++++-------
>  drivers/infiniband/core/umem.c            |  5 ++--
>  drivers/iommu/dma-iommu.c                 | 21 +++++++++++++----
>  drivers/virtio/virtio_ring.c              | 10 ++++----
>  include/linux/dma-mapping.h               | 15 ++++++++----
>  include/trace/events/dma.h                |  4 +++-
>  kernel/dma/debug.c                        |  9 ++++----
>  kernel/dma/direct.h                       |  7 +++---
>  kernel/dma/mapping.c                      |  6 +++++
>  mm/hmm.c                                  |  4 ++--
>  10 files changed, 86 insertions(+), 33 deletions(-)

Marek,

Despite the "RDMA ..." tag in the subject, the diffstat clearly shows that
you are the appropriate person to take this patch.

Thanks.


> ---
> base-commit: 11439c4635edd669ae435eec308f4ab8a0804808
> change-id: 20260305-dma-debug-overlap-21487c3fa02c
> 
> Best regards,
> --  
> Leon Romanovsky <leonro@nvidia.com>
>