Re: [PATCH v2 0/3] Support attaching PASID to the blocked_domain

[Yi Liu <yi.l.liu@intel.com>]

On 2024/10/22 17:44, Vasant Hegde wrote:
> Hi Yi,
> 
> 
> On 10/18/2024 11:28 AM, Yi Liu wrote:
>> During the review of iommufd pasid series, Kevin and Jason suggested
>> attaching PASID to the blocked domain hence replacing the usage of
>> remove_dev_pasid() op [1]. This makes sense as it makes the PASID path
>> aligned with the RID path which attaches the RID to the blocked_domain
>> when it is to be blocked. To do it, it requires passing the old domain
>> to the iommu driver. This has been done in [2].
> 
> I understand attaching RID to blocked_domain. But I am not getting why
> we have to do same for PASID. In remove_dev_pasid() path we clear the entry in
> PASID table (AMD case GCR3 table). So no further access is allowed anyway.
> 
> Is it just to align with RID flow -OR- do we have any other reason?

yes, this is also my understanding.:)

Regards,
Yi Liu

> 
> -Vasant
> 
> 
>>
>> This series makes the Intel iommu driver and ARM SMMUv3 driver support
>> attaching PASID to the blocked domain. While the AMD iommu driver does
>> not have the blocked domain yet, so still uses the remove_dev_pasid() op.
>>
>> [1] https://lore.kernel.org/linux-iommu/20240816130202.GB2032816@nvidia.com/
>> [2] https://lore.kernel.org/linux-iommu/20241018055402.23277-2-yi.l.liu@intel.com/
>>
>> v2:
>>   - Add Kevin's r-b
>>   - Adjust the order of patch 03 of v1, it should be the first patch (Baolu)
>>
>> v1: https://lore.kernel.org/linux-iommu/20240912130653.11028-1-yi.l.liu@intel.com/
>>
>> Regards,
>> 	Yi Liu
>>
>> Jason Gunthorpe (1):
>>    iommu/arm-smmu-v3: Make the blocked domain support PASID
>>
>> Yi Liu (2):
>>    iommu: Add a wrapper for remove_dev_pasid
>>    iommu/vt-d: Make the blocked domain support PASID
>>
>>   drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 12 ++++-----
>>   drivers/iommu/intel/iommu.c                 | 19 ++++++++-----
>>   drivers/iommu/intel/pasid.c                 |  3 ++-
>>   drivers/iommu/iommu.c                       | 30 ++++++++++++++++-----
>>   4 files changed, 45 insertions(+), 19 deletions(-)
>>

-- 
Regards,
Yi Liu