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

[fangyu.yu@linux.alibaba.com]

>> From: Fangyu Yu <fangyu.yu@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@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 ?

Good catch, no it doesn't. This patch didn't add a pt_dirty_supported(),
so it falls back to the default "always true", which isn't right --
iommu.c only sets TC.GADE and wires up dirty_ops for second-stage
domains, first-stage never gets TC.SADE set.

Thanks,
Fangyu

>
>Jason
>

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