On Wed, Aug 17, 2022 at 09:20:18AM +0800, Lu Baolu wrote:
> +static int intel_svm_set_dev_pasid(struct iommu_domain *domain,
> + struct device *dev, ioasid_t pasid)
> +{
> + struct device_domain_info *info = dev_iommu_priv_get(dev);
> + struct intel_iommu *iommu = info->iommu;
> + struct iommu_sva *sva;
> + int ret = 0;
> +
> + mutex_lock(&pasid_mutex);
> + /*
> + * Detach the domain if a blocking domain is set. Check the
> + * right domain type once the IOMMU driver supports a real
> + * blocking domain.
> + */
> + if (!domain || domain->type == IOMMU_DOMAIN_UNMANAGED) {
> + intel_svm_unbind_mm(dev, pasid);
See, I think this is exactly the wrong way to use the ops
The blockin domain ops should have its own function that just
unconditionally calls intel_svm_unbind_mm()
> + } else {
> + struct mm_struct *mm = domain->mm;
> +
> + sva = intel_svm_bind_mm(iommu, dev, mm);
> + if (IS_ERR(sva))
> + ret = PTR_ERR(sva);
And similarly the SVA domain should have its own op that does this SVM
call.
Muxing the ops with tests on the domain is an anti-pattern. In fact I
would say any time you see an op testing the domain->type it is very
suspicious.
Jason
