Re: [RFC PATCH 0/5] KVM: arm64: New PTE dirty-page encoding, HAFDBS new usage

[Marc Zyngier]

On Tue, 01 Sep 2026 18:15:51 +0100,
Leonardo Bras <leo.bras@xxxxxxx> wrote:
> 
> This series have 2 main goals:
> 
> 1 - Patches #1,#2,#3 : Change the PTE descriptor to use WD/WC/RO encodings
>     making use of the DBM bit, adapting all usages, and

What are WD and WC? I can sort of guess that this is write-dirty and
write clean, but that's not exactly obvious. More importantly, you
don't even explain *why* anything needs changing...

> 2 - Patches #4,#5 are an RFC on using HAFDBS on a guest to avoid resetting
>     all PTEs to WC when dirty-logging starts, speeding-up startup.
> 
> (1) will also introduce a new walker for cleaning the dirty-bit, which will
> clear the DBM bit if it's a block mapping (hugepage). This is needed as on
> lazy-splitting we need to fault a write so we can do the lazy splitting.
> This is needed for both the next patches, and for HDBSS & HACDBS
> enablement.

Again, this is incredibly opaque to the reviewer. What is the problem
you are trying to solve? This is what a cover letter is for.

	M.

-- 
Without deviation from the norm, progress is not possible.