Re: [PATCH v1 03/14] mm: add iomem vma selection for memory migration

[Christoph Hellwig]

On Tue, Aug 24, 2021 at 10:48:17PM -0500, Alex Sierra wrote:
>               } else {
> -                     if (!(migrate->flags & MIGRATE_VMA_SELECT_SYSTEM))
> +                     if (!(migrate->flags & MIGRATE_VMA_SELECT_SYSTEM) &&
> +                         !(migrate->flags & MIGRATE_VMA_SELECT_IOMEM))
>                               goto next;
>                       pfn = pte_pfn(pte);
>                       if (is_zero_pfn(pfn)) {

.. also how is this going to work for the device public memory?  That
should be pte_special() an thus fail vm_normal_page.