Re: [PATCH v2 3/6] iommu/vt-d: Make intel_iommu_set_dev_pasid() to handle domain replacement

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

On 9/13/24 8:21 PM, Yi Liu wrote:
> On 2024/9/13 09:42, Baolu Lu wrote:
>> On 9/12/24 9:04 PM, Yi Liu wrote:
>>> @@ -4325,24 +4363,18 @@ static int intel_iommu_set_dev_pasid(struct 
>>> iommu_domain *domain,
>>>           ret = intel_pasid_setup_second_level(iommu, dmar_domain,
>>>                                dev, pasid);
>>>       if (ret)
>>> -        goto out_unassign_tag;
>>> +        goto out_undo_dev_pasid;
>>> -    dev_pasid->dev = dev;
>>> -    dev_pasid->pasid = pasid;
>>> -    spin_lock_irqsave(&dmar_domain->lock, flags);
>>> -    list_add(&dev_pasid->link_domain, &dmar_domain->dev_pasids);
>>> -    spin_unlock_irqrestore(&dmar_domain->lock, flags);
>>> +    if (old)
>>> +        domain_remove_dev_pasid(old, dev, pasid);
>>>       if (domain->type & __IOMMU_DOMAIN_PAGING)
>>>           intel_iommu_debugfs_create_dev_pasid(dev_pasid);
>>>       return 0;
>>> -out_unassign_tag:
>>> -    cache_tag_unassign_domain(dmar_domain, dev, pasid);
>>> -out_detach_iommu:
>>> -    domain_detach_iommu(dmar_domain, iommu);
>>> -out_free:
>>> -    kfree(dev_pasid);
>>> +
>>> +out_undo_dev_pasid:
>>> +    domain_remove_dev_pasid(domain, dev, pasid);
>>>       return ret;
>>>   }
>>
>> Do you need to re-install the old domain to the pasid entry in the
>> failure path?
> 
> yes, but no. The old domain is still installed in the pasid entry
> when the failure happened. :)

I am afraid not. The old domain has already been cleaned up by
intel_pasid_tear_down_entry(). Or not?

Thanks,
baolu