Re: [PATCH v5 5/5] iommu/hyperv: Add page-selective IOTLB flush support

[Jason Gunthorpe]

On Fri, 04 Sep 2026 15:55:12 +0800, Yu Zhang <zhangyu1@xxxxxxxxxxxxxxxxxxx> wrote:
> Add page-selective IOTLB flush using HVCALL_FLUSH_DEVICE_DOMAIN_LIST.
> This hypercall accepts a list of (page_number, page_mask_shift) entries,
> enabling finer-grained IOTLB invalidation compared to the domain-wide
> HVCALL_FLUSH_DEVICE_DOMAIN used by hv_iommu_flush_iotlb_all().
> 
> hv_iommu_calc_flush_range() computes the smallest power-of-two aligned
> range that covers the target IOVA region, producing a single flush
> descriptor. This may over-flush when the range is not naturally aligned,
> matching the approach used by Intel VT-d PSI. If the page-selective
> flush fails, the code falls back to a full domain flush.
> 
> [...]

Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx>

-- 
Jason