Re: [PATCH v4 10/13] iommu/vt-d: Fail SVA domain replacement

[Baolu Lu <baolu.lu@linux.intel.com>]

On 11/5/24 13:30, Yi Liu wrote:
> On 2024/11/5 11:30, Baolu Lu wrote:
>> On 11/4/24 21:18, Yi Liu wrote:
>>> There is no known usage that will attach SVA domain or detach SVA domain
>>> by replacing PASID to or from SVA domain. It is supposed to use the
>>> iommu_sva_{un}bind_device() which invoke the iommu_{at|de} 
>>> tach_device_pasid().
>>> So Intel iommu driver decides to fail the domain replacement if the old
>>> domain or new domain is SVA type.
>>
>> I would suggest dropping this patch.
>>
>> The iommu driver now supports switching SVA domains to and from other
>> types of domains. The current limitation comes from the iommu core,
>> where the SVA interface doesn't use replace.
> 
> I also noticed other iommu drivers (like ARM SMMUv3 and AMD iommu) would
> support SVA replacement. So may we also make intel_svm_set_dev_pasid() be
> able to handle the case in which @old==non-null? At first, it looks to be
> dead code when SVA interface does not use replace. But this may make all
> drivers aligned.

yeah, that works for me.