Re: [RFCv2 00/13] TDX and guest memory unmapping

From: Matthew Wilcox
Date: Fri Apr 16 2021 - 12:46:31 EST


On Fri, Apr 16, 2021 at 06:40:53PM +0300, Kirill A. Shutemov wrote:
> TDX integrity check failures may lead to system shutdown host kernel must
> not allow any writes to TD-private memory. This requirment clashes with
> KVM design: KVM expects the guest memory to be mapped into host userspace
> (e.g. QEMU).
>
> This patchset aims to start discussion on how we can approach the issue.
>
> The core of the change is in the last patch. Please see more detailed
> description of the issue and proposoal of the solution there.

This seems to have some parallels with s390's arch_make_page_accessible().
Is there any chance to combine the two, so we don't end up with duplicated
hooks all over the MM for this kind of thing?

https://patchwork.kernel.org/project/kvm/cover/20200214222658.12946-1-borntraeger@xxxxxxxxxx/

and recent THP/Folio-related discussion:
https://lore.kernel.org/linux-mm/20210409194059.GW2531743@xxxxxxxxxxxxxxxxxxxx/