Re: [PATCH Part1 RFC v4 15/36] x86/mm: Add support to validate memory when changing C-bit

Borislav Petkov
2021-08-17T20:44:18Z

On Tue, Aug 17, 2021 at 03:34:41PM -0500, Brijesh Singh wrote:
> I am not seeing any strong reason to sanity check the reserved bit in the
> psc_entry. The fields in the psc_entry are input from guest to the
> hypervisor. The hypervisor cannot trick a guest by changing anything in the
> psc_entry because guest does not read the hypervisor filled value. I am okay
> with the psc_hdr because we need to read the current and end entry after the
> PSC completes to determine whether it was successful and sanity checking PSC
> header makes much more sense. Let me know if you are okay with it ?

Ok, fair enough.

Thx.

--
Regards/Gruss,
Boris.