Received-SPF: softfail (google.com: domain of transitioning linux-kernel-owner@vger.kernel.org does not designate 23.128.96.19 as permitted sender) client-ip=23.128.96.19;
Message-ID: <55cd5349e58c44113ae976e04ea4c6dc0cfba66d.camel@kernel.org>
Subject: Re: [PATCH V3 17/30] x86/sgx: Support modifying SGX page type
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:   Wed, 06 Apr 2022 10:32:02 +0300
In-Reply-To: <70962fc4-1624-2fd8-4d8d-f1a31001e165@intel.com>
References: <cover.1648847675.git.reinette.chatre@intel.com>
         <bac6e77fe04100d6bfebd4e13aa9b916f82bfea6.1648847675.git.reinette.chatre@intel.com>
         <Ykvqf3Ws6jlN5g+p@kernel.org>
         <b41d81ebcb6934765d7f37d4ce95baa16ec9b5d2.camel@kernel.org>
         <d8cc2142-c50d-fbd9-425f-01e279c9a0f1@intel.com>
         <94f62e19a630792f78e3c48895dfb792ecb02c6c.camel@kernel.org>
         <70962fc4-1624-2fd8-4d8d-f1a31001e165@intel.com>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
User-Agent: Evolution 3.42.4 
MIME-Version: 1.0
Precedence: bulk

On Tue, 2022-04-05 at 11:59 -0700, Reinette Chatre wrote:
> Hi Jarkko,
>=20
> On 4/5/2022 11:41 AM, Jarkko Sakkinen wrote:
> > On Tue, 2022-04-05 at 10:05 -0700, Reinette Chatre wrote:
> > > Hi Jarkko,
> > >=20
> > > On 4/5/2022 8:34 AM, Jarkko Sakkinen wrote:
> > > > On Tue, 2022-04-05 at 10:06 +0300, Jarkko Sakkinen wrote:
> > >=20
> > > > > >=20
> > > > >=20
> > > > > To be coherent with other names, this should be
> > > > > SGX_IOC_ENCLAVE_MODIFY_TYPES.
> > >=20
> > > This is not such a clear change request to me:
> > >=20
> > > SGX_IOC_ENCLAVE_ADD_PAGES - add multiple pages
> > > SGX_IOC_ENCLAVE_RESTRICT_PERMISSIONS - restrict multiple permissions
> > > SGX_IOC_ENCLAVE_REMOVE_PAGES - remove multiple pages
> > > SGX_IOC_ENCLAVE_MODIFY_TYPE - set a single type
> > >=20
> > > Perhaps it should rather be SGX_IOC_ENCLAVE_SET_TYPE to indicate that
> > > there is a single target type as opposed to the possibility
> > > of multiple source types (TCS and regular pages can be trimmed).
> > >=20
> > > >=20
>=20
> What is your opinion about what the ioctl() name should be? I prefer
> to obtain a confirmation from you since you originally [1] requested
> SGX_IOC_ENCLAVE_MODIFY_TYPE.

s/TYPE/TYPES/g i.e. SGX_IOC_ENCLAVE_MODIFY_TYPES is fine.
>=20
> > > > This should take only page type given that flags are zeroed:
> > > >=20
> > > > EPCM(DS:RCX).R :=3D 0;
> > > > EPCM(DS:RCX).W :=3D 0;
> > > > EPCM(DS:RCX).X :=3D 0;=20
> > > >=20
> > >=20
> > > ok, this was how it was done in V1 [1] and I can go back to that.
> >=20
> > I would name the fields as "flags" and "page_type" just to align
> > names with SGX instead of trying to mimim "posix names". Otherwise,=C2=
=A0
> > I support that.
>=20
> I will move this ioctl() to use "page_type" instead of "secinfo"
> within struct sgx_enclave_modify_type.
>=20
> Your guidance of "flags" is not clear to me. I assume that you
> refer to the field for struct sgx_enclave_restrict_permissions
> where I think "permissions" to only contain the new permissions
> would be more appropriate. None of the other values in
> secinfo.flags are relevant.

I'm fine with your permissions field to the restrict ioctl.

>=20
> Reinette
>=20
> [1] https://lore.kernel.org/linux-sgx/Yav9g4+L8zg48DRf@iki.fi/
>=20

BR, Jarkko