From: Jason Gunthorpe jgg@nvidia.com Sent: Wednesday, November 16, 2022 8:33 AM
This is the comment:
/*
- This is part of the VFIO compatibility support for VFIO_TYPE1_IOMMU.
That
- mode permits splitting a mapped area up, and then one of the splits is
- unmapped. Doing this normally would cause us to violate our invariant
of
- pairing map/unmap. Thus, to support old VFIO compatibility disable
support
- for batching consecutive PFNs. All PFNs mapped into the iommu are
done
in
- PAGE_SIZE units, not larger or smaller.
*/ static int batch_iommu_map_small(struct iommu_domain *domain, unsigned long iova, phys_addr_t paddr, size_t size, int prot)
I meant a comment in iopt_calculate_iova_alignment().
How about "see batch_iommu_map_small()" ?
yes, that works.
btw is there a better name to reflect strict PAGE_SIZE only?
disable_large_pages literally implies no >PAGE_SIZE alignment. This is the confusion easily raised why it also refers to no subpage alignment.