Re: [PATCH v3 2/3] KVM: arm64: Introduce KVM_PGTABLE_WALK_SKIP_LEVEL* walk flags

[Wei-Lin Chang]

On Mon, Jul 13, 2026 at 11:14:32AM +0100, Leonardo Bras wrote:
> On Sat, Jul 11, 2026 at 06:53:28AM +0100, Wei-Lin Chang wrote:
> > Hi Leonardo,
> 
> Hi Wei-Lin, thanks for reviewing!
> 
> > 
> > On Wed, Jul 08, 2026 at 02:40:58PM +0100, Leonardo Bras wrote:
> > > Add the new walking flags that tell kvm_pgtable_walk() to skip lower levels
> > > when walking the pagetables.
> > > 
> > > Signed-off-by: Leonardo Bras <leo.bras@xxxxxxx>
> > > ---
> > >  arch/arm64/include/asm/kvm_pgtable.h | 13 +++++++++++++
> > >  arch/arm64/kvm/hyp/pgtable.c         | 19 ++++++++++++++++---
> > >  2 files changed, 29 insertions(+), 3 deletions(-)
> > > 
> > > diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h
> > > index 41a8687938eb..20c7c12e0e76 100644
> > > --- a/arch/arm64/include/asm/kvm_pgtable.h
> > > +++ b/arch/arm64/include/asm/kvm_pgtable.h
> > > @@ -311,31 +311,44 @@ typedef bool (*kvm_pgtable_force_pte_cb_t)(u64 addr, u64 end,
> > >   * @KVM_PGTABLE_WALK_SHARED:		Indicates the page-tables may be shared
> > >   *					with other software walkers.
> > >   * @KVM_PGTABLE_WALK_IGNORE_EAGAIN:	Don't terminate the walk early if
> > >   *					the walker returns -EAGAIN.
> > >   * @KVM_PGTABLE_WALK_SKIP_BBM_TLBI:	Visit and update table entries
> > >   *					without Break-before-make's
> > >   *					TLB invalidation.
> > >   * @KVM_PGTABLE_WALK_SKIP_CMO:		Visit and update table entries
> > >   *					without Cache maintenance
> > >   *					operations required.
> > > + * @KVM_PGTABLE_WALK_SKIP_LEVEL0:	Skip visiting level-0+ entries
> > > + * @KVM_PGTABLE_WALK_SKIP_LEVEL1:	Skip visiting level-1+ entries
> > > + * @KVM_PGTABLE_WALK_SKIP_LEVEL2:	Skip visiting level-2+ entries
> > > + * @KVM_PGTABLE_WALK_SKIP_LEVEL3:	Skip visiting level-3 entries
> > 
> > Just a drive-by nit:
> > Maybe avoid the level-$LEVEL terminology? Since as you said there is
> > level -1 in the architecture, in that case you'd have to write
> > "level--1" which is awkward :)
> 
> It would have to be something like level-(-1), or we could call it level+1, 
> LOL.

Good one! :)

> 
> Seriously though, yes it's bad.
> I could call it level_1 entries, but level_-1 also seems weird :(
> level(1) & level(-1) could work, but looks like a function now
> 
> maybe just saying 'level 1' and 'level -1' can be better.

Yeah, I generally also just go with the space when it's text.
For code/variables, I guess a direct concatenation like what's done here
for the enum is good.

Thanks,
Wei-Lin Chang

> 
> What do you think?
> 
> Thanks!
> Leo
> 
>