> From: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>
> Sent: Thursday, March 2, 2023 9:00 AM
>
> static int idxd_enable_system_pasid(struct idxd_device *idxd)
> {
> - return -EOPNOTSUPP;
> + struct pci_dev *pdev = idxd->pdev;
> + struct device *dev = &pdev->dev;
> + struct iommu_domain *domain;
> + union gencfg_reg gencfg;
> + ioasid_t pasid;
> + int ret;
> +
> + domain = iommu_get_domain_for_dev(dev);
> + if (!domain || domain->type == IOMMU_DOMAIN_BLOCKED)
> + return -EPERM;
what about UNMANAGED?
> +
> + pasid = iommu_sva_reserve_pasid(1, dev->iommu->max_pasids);
> + if (pasid == IOMMU_PASID_INVALID)
> + return -ENOSPC;
as commented in last patch we can just pass a device pointer to a
general allocation interface.
> +
> + ret = iommu_attach_device_pasid(domain, dev, pasid);
> + if (ret) {
> + dev_err(dev, "failed to attach device pasid %d, domain
> type %d",
> + pasid, domain->type);
> + iommu_sva_unreserve_pasid(pasid);
> + return ret;
> + }
> +
> + /* Since we set user privilege for kernel DMA, enable completion IRQ
> */
> + gencfg.bits = ioread32(idxd->reg_base + IDXD_GENCFG_OFFSET);
> + gencfg.user_int_en = 1;
> + iowrite32(gencfg.bits, idxd->reg_base + IDXD_GENCFG_OFFSET);
> + idxd->pasid = pasid;
Why does user privilege requires a completion interrupt?
Or instead it's more due to doing kernel DMA itself then we certainly
don't want to poll in the kernel?
