On Tue, Jul 08, 2025 at 12:27:09PM +0200, Marek Szyprowski wrote:

On 30.06.2025 15:38, Christoph Hellwig wrote:

quoted

On Fri, Jun 27, 2025 at 08:02:13PM +0300, Leon Romanovsky wrote:

quoted

quoted

Thanks for this rework! I assume that the next step is to add map_phys
callback also to the dma_map_ops and teach various dma-mapping providers
to use it to avoid more phys-to-page-to-phys conversions.

Probably Christoph will say yes, however I personally don't see any
benefit in this. Maybe I wrong here, but all existing .map_page()
implementation platforms don't support p2p anyway. They won't benefit
from this such conversion.

I think that conversion should eventually happen, and rather sooner than
later.

Agreed.

Applied patches 1-7 to my dma-mapping-next branch. Let me know if one 
needs a stable branch with it.

Thanks a lot, I don't think that stable branch is needed. Realistically
speaking, my VFIO DMA work won't be merged this cycle, We are in -rc5,
it is complete rewrite from RFC version and touches pci-p2p code (to
remove dependency on struct page) in addition to VFIO, so it will take
time.

Regarding, last patch (hmm), it will be great if you can take it.
We didn't touch anything in hmm.c this cycle and have no plans to send PR.
It can safely go through your tree.

Leon, it would be great if You could also prepare an incremental patch 
adding map_phys callback to the dma_maps_ops, so the individual 
arch-specific dma-mapping providers can be then converted (or simplified 
in many cases) too.

Sure, will do.

Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland