Re: [PATCH 1/2] mm/cma: accept memory of multi-range CMA areas

[Gupta, Pankaj]

> > > On systems with unaccepted memory, memblock allocations accept the
> > > allocated range, but when cma_declare_contiguous_multi() uses open coded
> > > allocation of multiple ranges, it reserves them with memblock_reserve()
> > > and they are never accepted.
> > >
> > > These pages are released to the buddy allocator by cma_activate_area()
> > > with __free_pages() that does not check for unaccepted memory, so the
> > > first access to such a page in a TDX or SEV-SNP guest is fatal.
> > >
> > > Accept the memory of each range when it is reserved.
> > Fix looks correct to me.
> >
> > Any easy way to reproduce and test on SEV SNP?
> I think running a VM with 16G or ram on a single node and with
>
> hugetlb_cma=8G memmap=2M\$0x2ffe00000 init_on_free=1

This triggered an unrelated issue for me, I sent a fix here:

https://lore.kernel.org/all/20261102113127.161823-1-pankaj.gupta@xxxxxxx/

I was able to verify this series with:

hugetlb_cma=8G cma=2G@0x200000000 init_on_free=1

Thanks,

Pankaj