Re: [PATCH 8/8] iommu/vt-d: Add set_dev_pasid callback for nested domain

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

On 2024/1/16 1:22, Jason Gunthorpe wrote:
> On Sun, Nov 26, 2023 at 10:34:28PM -0800, Yi Liu wrote:
> 
>> +static int intel_nested_set_dev_pasid(struct iommu_domain *domain,
>> +				      struct device *dev, ioasid_t pasid)
>> +{
>> +	struct device_domain_info *info = dev_iommu_priv_get(dev);
>> +	struct dmar_domain *dmar_domain = to_dmar_domain(domain);
>> +	struct intel_iommu *iommu = info->iommu;
>> +	struct dev_pasid_info *dev_pasid;
>> +	unsigned long flags;
>> +	int ret = 0;
>> +
>> +	if (!pasid_supported(iommu))
>> +		return -EOPNOTSUPP;
>> +
>> +	if (iommu->agaw < dmar_domain->s2_domain->agaw)
>> +		return -EINVAL;
>> +
>> +	ret = prepare_domain_attach_device(&dmar_domain->s2_domain->domain, dev);
>> +	if (ret)
>> +		return ret;
>> +
>> +	dev_pasid = kzalloc(sizeof(*dev_pasid), GFP_KERNEL);
>> +	if (!dev_pasid)
>> +		return -ENOMEM;
>> +
>> +	ret = domain_attach_iommu(dmar_domain, iommu);
>> +	if (ret)
>> +		goto err_free;
>> +
>> +	ret = intel_pasid_setup_nested(iommu, dev, pasid, dmar_domain);
>> +	if (ret)
>> +		goto err_detach_iommu;
>> +
>> +	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);
>> +
>> +	return 0;
>> +err_detach_iommu:
>> +	domain_detach_iommu(dmar_domain, iommu);
>> +err_free:
>> +	kfree(dev_pasid);
>> +	return ret;
>> +}
> This seems alot longer than I'd think it should be, why isn't it
> exactly the same code as the other set_dev_pasid's?

Yes. It should be. The only difference is how to configure the pasid
entry.

Best regards,
baolu