Re: [PATCH 10/22] KVM: arm64: Plumb through access descriptor for stage-1

[Oliver Upton <oupton@kernel.org>]

On Wed, Sep 23, 2026 at 05:21:04PM +0100, Leonardo Bras wrote:
> > @@ -1459,12 +1461,14 @@ static int kvm_translate_vncr(struct kvm_vcpu *vcpu, bool *is_gmem)
> >  
> >  	va =  read_vncr_el2(vcpu);
> >  
> > -	ret = __kvm_translate_va(vcpu, &vt->wi, &vt->wr, va);
> > +	access.type = WALK_ACCESS_NV2;
> > +	access.ia = va;
> > +	access.write = write_fault;
> 
> It's not clear on why we need the proxy var write_fault.

write_fault gets used immediately below when we fault in the PFN.

> > +
> > +	ret = __kvm_translate_va(vcpu, &vt->wi, &vt->wr, &access);
> >  	if (ret)
> >  		return ret;
> >  
> > -	write_fault = kvm_is_write_fault(vcpu);
> > -
> >  	mmu_seq = vcpu->kvm->mmu_invalidate_seq;
> >  	smp_rmb();
> >  
> > -- 
> > 2.47.3
> > 
> 
> IIUC:
> In general terms, change some function signatures to replace va to a struct 
> pointer that contains extra information, such as walk type and it being a 
> write fault.
> 
> On top of that, there are 2 extra kvm_walk_access flags added here, and I 
> see them being attributed, but no information on what they do different.
> 
> Since there are already flags being treated somewhere, maybe a patch just 
> adding these new flags and showing what they do differently on the 
> processing, then adding the remaining of this patch in a new one would make 
> them easier to understand. 
> 
> (I still haven't read what those flags do differently in the next patches, 
> but seems like a no-op at this point, even though it should be doing 
> something different here. Please help me understand if I am missing some 
> context)

As I mention in the changelog, I'm adding annotations to the stage-1
translation fetches so later changes to the PTW can emulate the correct
behavior based on the intent of the translation fetch. These prepatory
patches are split off to keep the whole series digestable, assuming a
degree of familiarity with nested.

Thanks,
Oliver