Re: [PATCH v9 2/9] mm/mmzone: Tag pg_data_t with crypto capabilities

[Kirill A. Shutemov]

On Mon, Jul 04, 2022 at 10:58:26AM -0300, Martin Fernandez wrote:
> Add a new member in the pg_data_t struct to tell whether the node
> corresponding to that pg_data_t is able to do hardware memory
> encryption.
> 
> This will be read from sysfs.
> 
> Signed-off-by: Martin Fernandez <martin.fernandez@xxxxxxxxxxxxx>
> ---
>  include/linux/mmzone.h | 3 +++
>  mm/page_alloc.c        | 1 +
>  2 files changed, 4 insertions(+)
> 
> diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
> index aab70355d64f..6fd4785f1d05 100644
> --- a/include/linux/mmzone.h
> +++ b/include/linux/mmzone.h
> @@ -883,6 +883,9 @@ typedef struct pglist_data {
>  	struct task_struct *kcompactd;
>  	bool proactive_compact_trigger;
>  #endif
> +
> +	bool crypto_capable;
> +

There's already pgdat->flags. Any reason we cannot encode it there?

>  	/*
>  	 * This is a per-node reserve of pages that are not available
>  	 * to userspace allocations.
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index e008a3df0485..147437329ac7 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -7729,6 +7729,7 @@ static void __init free_area_init_node(int nid)
>  	pgdat->node_id = nid;
>  	pgdat->node_start_pfn = start_pfn;
>  	pgdat->per_cpu_nodestats = NULL;
> +	pgdat->crypto_capable = memblock_node_is_crypto_capable(nid);
>  
>  	if (start_pfn != end_pfn) {
>  		pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid,
> -- 
> 2.30.2
> 

-- 
  Kiryl Shutsemau / Kirill A. Shutemov