Re: [PATCH 02/11] iommu/amd: Introduce struct protection_domain.pd_mode

[Vasant Hegde <vasant.hegde@amd.com>]

Jason,


On 8/8/2023 9:00 PM, Jason Gunthorpe wrote:
> On Tue, Aug 08, 2023 at 10:02:23AM +0000, Vasant Hegde wrote:
>> From: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
>>
>> This enum variable is used to track the type of page table used by the
>> protection domain. It will replace the protection_domain.flags in
>> subsequent series.
>>
>> Suggested-by: Jason Gunthorpe <jgg@ziepe.ca>
>> Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
>> Signed-off-by: Vasant Hegde <vasant.hegde@amd.com>
>> ---
>>  drivers/iommu/amd/amd_iommu_types.h | 7 +++++++
>>  drivers/iommu/amd/iommu.c           | 3 +++
>>  2 files changed, 10 insertions(+)
>>
>> diff --git a/drivers/iommu/amd/amd_iommu_types.h b/drivers/iommu/amd/amd_iommu_types.h
>> index 0d339e022572..5e89032b3dee 100644
>> --- a/drivers/iommu/amd/amd_iommu_types.h
>> +++ b/drivers/iommu/amd/amd_iommu_types.h
>> @@ -555,6 +555,12 @@ struct amd_io_pgtable {
>>  	u64			*pgd;		/* v2 pgtable pgd pointer */
>>  };
>>  
>> +enum protection_domain_mode {
>> +	PD_MODE_PT = 0,
>> +	PD_MODE_V1,
>> +	PD_MODE_V2,
>> +};
> 
> PD_MODE_PT is redundant because the domain->type ==
> IOMMU_DOMAIN_IDENTITY already indicates identity. It is better not to
> denormalize the data structures.

We need to track how we have setup the hardware page table here. We can use
`IOMMU_DOMAIN_IDENTITY` for PT mode, but we don't have anything for other two
modes. So having macros makes it easy. Hence we have introduced new macros for
protection domain.

-Vasant