Re: [PATCH 05/22] KVM: arm64: nv: Pass an access descriptor for stage-2 walks

[Oliver Upton <oupton@kernel.org>]

On Mon, Sep 21, 2026 at 06:28:50PM +0100, Leonardo Bras wrote:
> > @@ -1642,9 +1655,11 @@ int __kvm_at_s12(struct kvm_vcpu *vcpu, u32 op, u64 vaddr)
> >  		return 0;
> >  
> >  	/* Do the stage-2 translation */
> > -	ipa = (par & GENMASK_ULL(47, 12)) | (vaddr & GENMASK_ULL(11, 0));
> > +	access.type = WALK_ACCESS_AT;
> > +	access.ia = (par & GENMASK_ULL(47, 12)) | (vaddr & GENMASK_ULL(11, 0));
> 
> What does this mask represent?

Keep in mind, this is pre-existing code... This mask is taking the GFN
from the output address of stage-1 translation and using it as the input
for stage-2.

Keep in mind nested only supports up to 48 bits of PA space.

> 
> IIUC, in general terms most of the changes are adapting the typing on 
> kvm_walk_nested_s2() & co to make use of the new struct kvm_walk_access 
> instead of just a PA.
> 
> I also see that flags & write are also added here, but not used anywhere.
> Maybe it would  be worth moving them to the patch that makes use of them, 
> instead leaving them here?

I can do that

Thanks,
Oliver