Re: [PATCH 07/25] x86/sgx: Move PTE zap code to separate function

From: Jarkko Sakkinen
Date: Tue Dec 28 2021 - 09:55:55 EST


On Mon, Dec 13, 2021 at 02:11:26PM -0800, Reinette Chatre wrote:
> Hi Jarkko,
>
> On 12/10/2021 11:52 PM, Jarkko Sakkinen wrote:
> > On Mon, 2021-12-06 at 13:30 -0800, Reinette Chatre wrote:
> > > Hi Jarkko,
> > >
> > > On 12/4/2021 2:59 PM, Jarkko Sakkinen wrote:
> > > > On Wed, Dec 01, 2021 at 11:23:05AM -0800, Reinette Chatre wrote:
> > > > > The SGX reclaimer removes page table entries pointing to pages that are
> > > > > moved to swap. SGX2 enables changes to pages belonging to an initialized
> > > > > enclave, for example changing page permissions. Supporting SGX2 requires
> > > > > this ability to remove page table entries that is available in the
> > > > > SGX reclaimer code.
> > > >
> > > > Missing: why SGX2 requirest this?
> > >
> > > The above paragraph states that SGX2 needs to remove page table entries
> > > because it modifies page permissions. Could you please elaborate what is
> > > missing?
> >
> > It does not say why SGX2 requires an ability to remove page table entries.
>
> Are you saying that modification of EPCM page permissions is not a reason to
> remove page table entries pointing to those pages?

So you have:

"Supporting SGX2 requires this ability to remove page table entries that is
available in the SGX reclaimer code"

Just write down where you need this ability (briefly).

/Jarkko