From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1753473AbdK3Qog (ORCPT <rfc822;w@1wt.eu>);
        Thu, 30 Nov 2017 11:44:36 -0500
Received: from mga07.intel.com ([134.134.136.100]:60237 "EHLO mga07.intel.com"
        rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
        id S1750926AbdK3Qoc (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
        Thu, 30 Nov 2017 11:44:32 -0500
X-ExtLoop1: 1
X-IronPort-AV: E=Sophos;i="5.45,341,1508828400"; 
   d="scan'208";a="8948106"
Date: Thu, 30 Nov 2017 18:44:25 +0200
From: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
To: Kai Huang <kai.huang@linux.intel.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>,
        platform-driver-x86@vger.kernel.org, x86@kernel.org,
        linux-kernel@vger.kernel.org, Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
        Borislav Petkov <bp@suse.de>,
        Janakarajan Natarajan <Janakarajan.Natarajan@amd.com>,
        Paolo Bonzini <pbonzini@redhat.com>,
        "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
        Kyle Huey <me@kylehuey.com>,
        Vikas Shivappa <vikas.shivappa@linux.intel.com>,
        Piotr Luc <piotr.luc@intel.com>,
        Grzegorz Andrejczuk <grzegorz.andrejczuk@intel.com>
Subject: Re: [PATCH v6 04/11] x86: define IA32_FEATUE_CONTROL.SGX_LC
Message-ID: <20171130164425.nhgkf22gbpjom2ez@linux.intel.com>
References: <1511889371.9392.58.camel@intel.com>
 <1511893683.9392.100.camel@intel.com>
 <20171128205324.pqojyfqbet3h7re4@linux.intel.com>
 <20171128212407.lky32cdghxqsxd4e@linux.intel.com>
 <1511904794.18982.7.camel@intel.com>
 <20171128215513.qp2bs6462eq4pkz4@linux.intel.com>
 <1511906403.18982.17.camel@intel.com>
 <20171128222141.pljpvoou7bglbzid@linux.intel.com>
 <20171129153815.mkjncw3t22sser3c@linux.intel.com>
 <1512011145.16342.3.camel@linux.intel.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <1512011145.16342.3.camel@linux.intel.com>
Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo
User-Agent: NeoMutt/20170609 (1.8.3)
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Thu, Nov 30, 2017 at 04:05:45PM +1300, Kai Huang wrote:
> On Wed, 2017-11-29 at 17:38 +0200, Jarkko Sakkinen wrote:
> > On Wed, Nov 29, 2017 at 12:21:41AM +0200, Jarkko Sakkinen wrote:
> > > On Tue, Nov 28, 2017 at 02:00:03PM -0800, Sean Christopherson
> > > wrote:
> > > > What about SGX_LC_ENABLE?  The title in the MSR section of the
> > > > SDM is
> > > > "SGX Launch Control Enable", and it's more consistent with the
> > > > other
> > > > bits defined in feature control.  I'd also prefer that name for
> > > > the
> > > > actual #define too, SGX_LAUNCH_CONTROL_ENABLE is overly verbose
> > > > IMO.
> > > 
> > > This is a bit ugly name but it is also very clear:
> > > 
> > >   FEATURE_CONTROL_SGX_LEPUBKEYHASH_WRITE_ENABLE
> > > 
> > > Just pushed update to the le branch. SGX_LC_ENABLE is a nice short
> > > name
> > > but it does not reflect the semantics.
> > > 
> > > Maybe we could combine these and name it as
> > > 
> > >   FEATURE_CONTROL_SGX_LC_WRITE_ENABLE
> > > 
> > > It is not as ugly and is very clear what it does.
> > 
> > I ended up with FEATURE_CONTROL_SGX_LC_WR. I think that is fairly
> > reasonable name for bit 17.
> 
> Why not using FEATURE_CONTROL_SGX_LE_WR? "LE_WR" is even used in SDM
> 41.2.2 Intel SGX Launch Control Configuration:
> 
> If IA32_FEATURE_CONTROL.LE_WR (bit 17) is set to 1 and
> IA32_FEATURE_CONTROL is locked on that logical processor,
> IA32_SGXLEPUBKEYHASH MSRs on that logical
> processor then the IA32_SGXLEPUBKEYHASHn MSR are writeable.

I'm fine with that name and since the spec uses it I think with lock
to that :-) Thanks for noting this!

/Jarkko