Re: [PATCHv7 10/14] x86/mm: Avoid load_unaligned_zeropad() stepping into unaccepted memory

Borislav Petkov
2022-07-26T10:21:59Z

On Tue, Jun 14, 2022 at 03:02:27PM +0300, Kirill A. Shutemov wrote:
> But, this approach does not work for unaccepted memory. For TDX, a load
> from unaccepted memory will not lead to a recoverable exception within
> the guest. The guest will exit to the VMM where the only recourse is to
> terminate the guest.

FTR, this random-memory-access-to-unaccepted-memory-is-deadly thing is
really silly. We should be able to handle such cases - because they do
happen often - in a more resilient way. Just look at the complex dance
this patch needs to do just to avoid this.

IOW, this part of the coco technology needs improvement.

Just sayin...

--
Regards/Gruss,
Boris.