Hi Andrew,

On Tue, 28 Jul 2020 14:55:53 -0700 Andrew Morton <akpm@linux-foundation.org> wrote:
> config CONTIG_ALLOC
>         def_bool (MEMORY_ISOLATION && COMPACTION) || CMA
> 
> says this is an improper combination.  And `make oldconfig' fixes it up.
> 
> What's happening here?

CONFIG_VIRTIO_MEM selects CONFIG_CONTIG_ALLOC ...

-- 
Cheers,
Stephen Rothwell