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The main blocker is IOMMUFD= 's current lack of P2P support (IOMMU_IOAS_MAP fails when the VA range is ba= cked by MMIO). dma-buf as a less ambiguous semantic for communicating this intent (rathe= r than the struggles of inferring what kind of memory is behind some VA range) m= akes a lot of sense. Based on tidbits we have gleaned, IOMMUFD P2P support intends to be built= on top of "Provide a new two step DMA mapping API" [1] and "vfio/pci: Allow = MMIO regions to be exported through dma-buf" [2]. Item [2] appears to have been picked up by "Host side (KVM/VFIO/IOMMUFD) = support for TDISP using TSM" [3]. Is the above understanding correct? On top of this, there would need to be a new IOMMUFD uapi, or extension t= o existing, which would accept an input dma-buf to map. Are there any patch= es in progress which include this? [1] https://lore.kernel.org/all/cover.1746424934.git.leon@kernel.org/ [2] https://lore.kernel.org/all/20250307052248.405803-1-vivek.kasireddy@i= ntel.com [3] https://lore.kernel.org/all/20250529053513.1592088-1-yilun.xu@linux.i= ntel.com Thanks, Alex