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

[Baolu Lu]

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