[RFC PATCH v3 02/10] iommupt: Add RISC-V dirty tracking PTE ops

[Jason Gunthorpe]

On Fri, Aug 21, 2026 at 09:27:42PM +0800, fangyu.yu at linux.alibaba.com wrote:
> From: Fangyu Yu <fangyu.yu at linux.alibaba.com>
> 
> Implement the three dirty-tracking hooks required by the generic page
> table framework for the RISC-V format:
> 
>   pt_entry_is_write_dirty():
>     Check the D bit (bit 7) in the PTE.
> 
>   pt_entry_make_write_clean():
>     Clear the D bit across the full contiguous range.
> 
>   pt_entry_make_write_dirty():
>     Atomically set D via try_cmpxchg64() on a single PTE.
> 
> Signed-off-by: Fangyu Yu <fangyu.yu at linux.alibaba.com>
> ---
>  drivers/iommu/generic_pt/fmt/riscv.h | 43 ++++++++++++++++++++++++++++
>  1 file changed, 43 insertions(+)
> 
> diff --git a/drivers/iommu/generic_pt/fmt/riscv.h b/drivers/iommu/generic_pt/fmt/riscv.h
> index 5692c033dbde..09581798e753 100644
> --- a/drivers/iommu/generic_pt/fmt/riscv.h
> +++ b/drivers/iommu/generic_pt/fmt/riscv.h
> @@ -226,6 +226,49 @@ static inline void riscvpt_attr_from_entry(const struct pt_state *pts,
>  }
>  #define pt_attr_from_entry riscvpt_attr_from_entry

Does this work for all stages or does it need  pt_dirty_supported ?

Jason