Re: [PATCH net-next v6 12/12] net/mlx5e: Add TX support for netmems

[Mina Almasry]

On Thu, Jun 19, 2025 at 9:07 AM Dragos Tatulea <dtatulea@xxxxxxxxxx> wrote:
> > You have to test ncdevmem tx on a platform with iommu enabled. Only in
> > this case the netmem_dma_unmap_page_attrs() may cause a problem, and
> > even then it's not a sure thing. It depends on the type of iommu and
> > type of dmabuf i think.
> >
> Is it worth adding a WARN_ON_ONCE(netmem_is_net_iov())
> in netmem_dma_unmap_page_attrs() after addr check to catch these kinds
> of misuse?
>

I would say it's worth it, but it's the same challenge you point to in
your reply: netmem_dma_unmap_page_attrs currently doesn't take in a
netmem, and it may be a big refactor not worth it if it's callers also
don't have a reference to the netmem readily available to pass it.

-- 
Thanks,
Mina