RE: [PATCH v2 2/6] iommu/vt-d: Remove scalable mode context entry setup from attach_dev

Tian, Kevin
2023-12-08T08:57:08Z

> From: Lu Baolu <baolu.lu@linux.intel.com>
> Sent: Tuesday, December 5, 2023 9:22 AM
>
> static int domain_context_mapping_one(struct dmar_domain *domain,
> struct intel_iommu *iommu,
> - struct pasid_table *table,
> u8 bus, u8 devfn)

since this is called in legacy now it's clearer to add a legacy_ prefix
to this and other related functions.

>
> - /* PASID table is mandatory for a PCI device in scalable mode. */
> - if (sm_supported(iommu) && !dev_is_real_dma_subdevice(dev)) {
> - /* Setup the PASID entry for requests without PASID: */
> - if (hw_pass_through && domain_type_is_si(domain))
> - ret = intel_pasid_setup_pass_through(iommu,
> - dev, IOMMU_NO_PASID);
> - else if (domain->use_first_level)
> - ret = domain_setup_first_level(iommu, domain, dev,
> - IOMMU_NO_PASID);
> - else
> - ret = intel_pasid_setup_second_level(iommu,
> domain,
> - dev, IOMMU_NO_PASID);
> - if (ret) {
> - dev_err(dev, "Setup RID2PASID failed\n");
> - device_block_translation(dev);
> - return ret;
> - }
> - }
> + if (dev_is_real_dma_subdevice(dev))
> + return 0;

is it a functional change? old code doesn't early exit for such device.