[RFC PATCH 1/2] KVM: arm64: Introduce S2 walker SKIP return options

[Will Deacon]

On Mon, May 18, 2026 at 12:22:47AM -0700, Oliver Upton wrote:
> On Fri, May 15, 2026 at 08:59:02PM +0100, Leonardo Bras wrote:
> > Introduce S2 walker return values:
> > - SKIP_CHILDREN: skip walking the children of the current node
> > - SKIP_SIBLINGS: skip waling the siblings of the current node
> > 
> > Also, modify __kvm_pgtable_visit() to fulfil the hing on above return
> > values. Current walkers should not be impacted
> 
> I'd rather see something based around new walk flags than introducing an
> entirely new mechanic around return values.
> 
> e.g. you could split the LEAF flag into separate flags for blocks v.
> pages:
> 
> 	KVM_PGTABLE_WALK_PAGE,
> 	KVM_PGTABLE_WALK_BLOCK,
> 	KVM_PGTABLE_WALK_LEAF	= KVM_PGTABLE_WALK_PAGE |
> 				  KVM_PGTABLE_WALK_BLOCK,
> 
> and then let __kvm_pgtable_visit() decide how to steer the walk. You may
> need some special handling to get the address arithmetic right when
> skipping over a table of page descriptors.

I was wondering along similar lines, but maybe it would be useful just
to pass a maximum level to the walker logic? That feels like the most
general case without complicating the existing logic.

Will