Re: [PATCH v4 11/13] iommu/vt-d: Add set_dev_pasid callback for nested domain

Yi Liu
2024-11-06T09:10:25Z

On 2024/11/6 16:41, Baolu Lu wrote:
> On 2024/11/6 16:17, Tian, Kevin wrote:
>>> From: Liu, Yi L <yi.l.liu@intel.com>
>>> Sent: Monday, November 4, 2024 9:19 PM
>>>
>>> +
>>> +    dev_pasid = domain_add_dev_pasid(domain, dev, pasid);
>>> +    if (IS_ERR(dev_pasid))
>>> +        return PTR_ERR(dev_pasid);
>>> +
>>> +    ret = domain_setup_nested(iommu, dmar_domain, dev, pasid, old);
>>> +    if (ret)
>>> +        goto out_remove_dev_pasid;
>>> +
>>> +    domain_remove_dev_pasid(old, dev, pasid);
>>> +
>>
>> forgot one thing. Why not required to create a debugfs entry for
>> nested dev_pasid?
>
> This debugfs node is only created for paging domain.

I think Kevin got one point. The debugfs is added when paging domain
is attached. How about the paging domains that is only used as nested
parent domain. We seem to lack a debugfs node for such paging domains.

--
Regards,
Yi Liu