Re: [PATCHv3 07/17] x86/mm: Preserve KeyID on pte_modify() and pgprot_modify()

From: Kirill A. Shutemov
Date: Fri Jun 15 2018 - 16:55:43 EST


On Fri, Jun 15, 2018 at 08:45:21PM +0000, Dave Hansen wrote:
> On 06/15/2018 01:45 PM, Kirill A. Shutemov wrote:
> > On Fri, Jun 15, 2018 at 04:58:24PM +0000, Dave Hansen wrote:
> >> On 06/15/2018 09:06 AM, Kirill A. Shutemov wrote:
> >>> I have no idea what such concept should be called. I cannot come with
> >>> anything better than PTE_PFN_MASK_MAX. Do you?
> >> PTE_PRESERVE_MASK
> >>
> >> Or maybe:
> >>
> >> PTE_MODIFY_PRESERVE_MASK
> > It just replacing one confusion with another. Preserve what?
>
> "Preserve this mask when modifying pte permission bits"

We preserve more than these bits. See _PAGE_CHG_MASK.

--
Kirill A. Shutemov