Re: [PATCH v5 2/2] vfio/type1: Set IOMMU_MMIO in dma->prot for MMIO-backed addresses

[Wei Wang]

On 1/26/26 3:19 AM, Wei Wang wrote:
> Before requesting the IOMMU driver to map an IOVA to a physical address,
> set the IOMMU_MMIO flag in dma->prot when the physical address corresponds
> to MMIO. This allows the IOMMU driver to handle MMIO mappings specially.
> For example, on AMD CPUs with SME enabled, the IOMMU driver avoids setting
> the C-bit if iommu_map() is called with IOMMU_MMIO set in prot. This
> prevents issues with PCIe P2P communication when IOVA is used.
>
> Signed-off-by: Wei Wang <wei.w.wang@xxxxxxxxxxx>
> Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx>
> ---
>   drivers/vfio/vfio_iommu_type1.c | 15 ++++++++++-----
>   1 file changed, 10 insertions(+), 5 deletions(-)
Hi Alex W,

The first patch in this series (the IOMMU part) has been merged and 
queued for stable. I haven’t seen further comments on the VFIO patch,
so I wanted to check whether you have any feedback or concerns about
it. Thanks.