Re: [PATCH 22/22] xen/arm64: Allow the admin to enable/disable the directmap

[Julien Grall <julien@xxxxxxx>]

Hi Stefano,

On 24/01/2023 00:12, Stefano Stabellini wrote:
> On Mon, 23 Jan 2023, Julien Grall wrote:
> Ah yes! I see it now that we are relying on the same area
> (alloc_xenheap_pages calls page_to_virt() then map_pages_to_xen()).
>
> map_pages_to_xen() is able to create pagetable entries at every level,
> but we need to make sure they are shared across per-cpu pagetables. To
> make that happen, we are pre-creating the L0/L1 entries here so that
> they become common across all per-cpu pagetables and then we let
> map_pages_to_xen() do its job.
>
> Did I understand it right?
Your understanding is correct.

> > I can add summary in the commit message.
> I would suggest to improve a bit the in-code comment on top of
> setup_directmap_mappings. I might also be able to help with the text
> once I am sure I understood what is going on :-)
--
Julien Grall