Re: [PATCH v4 06/16] x86/virt/tdx: Improve PAMT refcounts allocation for sparse memory

[Edgecombe, Rick P]

On Thu, 2025-11-27 at 15:57 +0000, Kiryl Shutsemau wrote:
> > Yes, I don't see what that comment is referring to. But we do need it,
> > because hypothetically the refcount mapping could have failed halfway. So we
> > will have pte_none()s for the ranges that didn't get populated. I'll use:
> > 
> > /* Refcount mapping could have failed part way, handle aborted mappings. */
> 
> It is possible that we can have holes in physical address space between
> 0 and max_pfn. You need the check even outside of "failed halfway"
> scenario.

Err. right. Was thinking of for_each_mem_pfn_range() on the populate side.
pamt_refcount_depopulate() is just called with the whole refcount virtual
address range. I'll add both reasons to the comment.