Re: [PATCH v7 00/29] KVM: s390: gmap rewrite, the real deal
From: Heiko Carstens
Date: Wed Feb 04 2026 - 10:39:38 EST
On Wed, Feb 04, 2026 at 04:02:29PM +0100, Claudio Imbrenda wrote:
> This series is the last big series of the gmap rewrite. It introduces
> the new code and actually uses it. The old code is then removed.
>
> KVM on s390 will now use the mmu_notifier, like most other
> architectures. The gmap address space is now completely separate from
> userspace; no level of the page tables is shared between guest mapping
> and userspace.
>
> One of the biggest advantages is that the page size of userspace is
> completely independent of the page size used by the guest. Userspace
> can mix normal pages, THPs, hugetlbfs, and more.
>
> It's now possible to have nested guests and guests with huge pages
> running on the same host. In fact, it's possible to have a nested
> guest on a guest with huge pages. Transparent hugepages are also
> possible.
FWIW, for everything that touches code which is not only KVM:
Acked-by: Heiko Carstens <hca@xxxxxxxxxxxxx>