Message-ID: <917c53ff755d9a20e1f4bcb48c70add8364d1065.camel@kernel.org>
Subject: Re: [PATCH 07/25] x86/sgx: Move PTE zap code to separate function
From:   Jarkko Sakkinen <jarkko@kernel.org>
To:     Reinette Chatre <reinette.chatre@intel.com>
Cc:     dave.hansen@linux.intel.com, tglx@linutronix.de, bp@alien8.de,
        luto@kernel.org, mingo@redhat.com, linux-sgx@vger.kernel.org,
        x86@kernel.org, seanjc@google.com, kai.huang@intel.com,
        cathy.zhang@intel.com, cedric.xing@intel.com,
        haitao.huang@intel.com, mark.shanahan@intel.com, hpa@zytor.com,
        linux-kernel@vger.kernel.org
Date:   Sat, 11 Dec 2021 09:52:11 +0200
In-Reply-To: <66151f3a-0e32-fc57-cb54-5b714588389b@intel.com>
References: <cover.1638381245.git.reinette.chatre@intel.com>
         <bd228c90c139437bb4fcc4b7b99063bfd3eb1439.1638381245.git.reinette.chatre@intel.com>
         <Yavy5JTYAkdZjnK2@iki.fi> <66151f3a-0e32-fc57-cb54-5b714588389b@intel.com>
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On Mon, 2021-12-06 at 13:30 -0800, Reinette Chatre wrote:
> Hi Jarkko,
>=20
> 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 a=
re
> > > moved to swap. SGX2 enables changes to pages belonging to an initiali=
zed
> > > enclave, for example changing page permissions. Supporting SGX2 requi=
res
> > > this ability to remove page table entries that is available in the
> > > SGX reclaimer code.
> >=20
> > Missing: why SGX2 requirest this?
>=20
> The above paragraph states that SGX2 needs to remove page table entries=
=20
> because it modifies page permissions. Could you please elaborate what is=
=20
> missing?

It does not say why SGX2 requires an ability to remove page table entries.

/Jarkko