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

Tian, Kevin
2023-12-22T06:58:05Z

> 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?