[PATCH v4 04/17] KVM: arm64: Add a heap allocator for the pKVM hyp

[Fuad Tabba]

Hi Vincent,

On Fri, 31 Jul 2026 at 15:36, 'Vincent Donnefort' via kernel-team
<kernel-team at android.com> wrote:
...
> +static int hyp_allocator_destroy_chunk(struct hyp_allocator *allocator,
> +                                      struct chunk_hdr *prev,
> +                                      struct chunk_hdr *chunk)
> +{
> +       struct chunk_hdr *next;
> +
> +       next = prev ? chunk_get_next(chunk) : NULL;
> +       if (!hyp_allocator_can_destroy_chunk(allocator, prev, next, chunk))
> +               return -EINVAL;
> +
> +       /* Last chunk in the allocator */
> +       if (!prev) {
> +               allocator->first_unmapped = chunk_unmapped(chunk);
> +               allocator->head = allocator->tail = NULL;
> +               return 0;
> +       }

hyp_allocator_destroy_chunk() has only two callers, both in
hyp_allocator_free(), and both pass a non-NULL prev. So this !prev
branch cannot be reached, and nor can the matching "if (!prev) return
true;" in hyp_allocator_can_destroy_chunk() or the false arm of "next
= prev ? chunk_get_next(chunk) : NULL".

The empty-allocator reset it looks like it is handling already happens
in hyp_allocator_reclaim_chunk(), in the addr == allocator->start
case. Could these be dropped?

With that:

Reviewed-by: Fuad Tabba <fuad.tabba at linux.dev>

Cheers,
/fuad