Re: [PATCH 02/14] KVM: arm64: Tear down unlinked stage-2 subtree after break-before-make

Oliver Upton
2022-09-09T10:08:51Z

On Wed, Sep 07, 2022 at 01:57:17PM -0700, David Matlack wrote:
> On Tue, Aug 30, 2022 at 07:41:20PM +0000, Oliver Upton wrote:
> [...]
> >
> > +static int stage2_map_walk_leaf(u64 addr, u64 end, u32 level, kvm_pte_t *ptep,
> > + struct stage2_map_data *data);
> > +
> > static int stage2_map_walk_table_pre(u64 addr, u64 end, u32 level,
> > kvm_pte_t *ptep,
> > struct stage2_map_data *data)
> > {
> > - if (data->anchor)
>
> Should @anchor and @childp be removed from struct stage2_map_data? This
> commit removes the only remaining references to them.

Yup, I'll toss those in the next spin.

> > - return 0;
> > + struct kvm_pgtable_mm_ops *mm_ops = data->mm_ops;
> > + kvm_pte_t *childp = kvm_pte_follow(*ptep, mm_ops);
> > + struct kvm_pgtable *pgt = data->mmu->pgt;
> > + int ret;
> >
> > if (!stage2_leaf_mapping_allowed(addr, end, level, data))
> > return 0;
> >
> > - data->childp = kvm_pte_follow(*ptep, data->mm_ops);
> > kvm_clear_pte(ptep);
> >
> > /*
> [...]
> > static int stage2_map_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep,
> > enum kvm_pgtable_walk_flags flag, void * const arg)
> > @@ -883,11 +849,9 @@ static int stage2_map_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep,
> > return stage2_map_walk_table_pre(addr, end, level, ptep, data);
> > case KVM_PGTABLE_WALK_LEAF:
> > return stage2_map_walk_leaf(addr, end, level, ptep, data);
> > - case KVM_PGTABLE_WALK_TABLE_POST:
> > - return stage2_map_walk_table_post(addr, end, level, ptep, data);
>
> kvm_pgtable_stage2_set_owner() still uses stage2_map_walker() with
> KVM_PGTABLE_WALK_TABLE_POST.

Good catch, I'll drop the TABLE_POST flag there as well.

Appreciate the reviews on the series.

--
Thanks,
Oliver