Re: [PATCH v6 7/9] xen/arm: unpopulate memory when domain is static

[Julien Grall <julien@xxxxxxx>]

Hi Penny,

On 07/06/2022 08:30, Penny Zheng wrote:
> Today when a domain unpopulates the memory on runtime, they will always
> hand the memory back to the heap allocator. And it will be a problem if domain
> is static.
>
> Pages as guest RAM for static domain shall be reserved to only this domain
> and not be used for any other purposes, so they shall never go back to heap
> allocator.
>
> This commit puts reserved pages on the new list resv_page_list only after
> having taken them off the "normal" list, when the last ref dropped.
>
> Signed-off-by: Penny Zheng <penny.zheng@xxxxxxx>
> Acked-by: Jan Beulich <jbeulich@xxxxxxxx>
> ---
> v6 changes:
> - refine in-code comment
> - move PGC_static !CONFIG_STATIC_MEMORY definition to common header
I don't understand why this change is necessary for this patch. AFAICT, 
all the users of PGC_static will be protected by #ifdef 
CONFIG_STATIC_MEMORY and therefore PGC_static should always be defined.
Cheers,

--
Julien Grall