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

[Jason Gunthorpe]

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?

Jason