RE: [PATCH v7 9/9] iommu/vt-d: Add iotlb flush for nested domain

From: Liu, Yi L yi.l.liu@intel.com Sent: Thursday, December 21, 2023 11:40 PM

+static void intel_nested_flush_cache(struct dmar_domain *domain, u64 addr,

• 		     unsigned long npages, u32 *error)
  

+{

• struct iommu_domain_info *info;
• unsigned long i;
• unsigned mask;
• u32 fault = 0;
• if (npages == U64_MAX)

• mask = 64 - VTD_PAGE_SHIFT;
  

• else

• mask = ilog2(__roundup_pow_of_two(npages));
  

• xa_for_each(&domain->iommu_array, i, info) {

• nested_flush_pasid_iotlb(info->iommu, domain, addr,
  

npages, 0);

so IOMMU_VTD_INV_FLAGS_LEAF is defined but ignored?

• if (domain->has_iotlb_device)
  

• 	continue;
  

• nested_flush_dev_iotlb(domain, addr, mask, &fault);
  

• if (fault & (DMA_FSTS_ITE | DMA_FSTS_ICE))
  

• 	break;
  

here you may add a note that we don't plan to forward invalidation queue error (i.e. IQE) to the caller as it's caused only by driver internal bug.

• if (!IS_ALIGNED(inv_entry.addr, VTD_PAGE_SIZE) ||
  

•     ((inv_entry.npages == U64_MAX) && inv_entry.addr)) {
  

• 	ret = -EINVAL;
  

• 	break;
  

• }
  

why is [non-zero-addr, U64_MAX] an error? Is it explicitly stated to be not supported by underlying helpers?