From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751119AbcEIF3W (ORCPT ); Mon, 9 May 2016 01:29:22 -0400 Received: from mga14.intel.com ([192.55.52.115]:52220 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750916AbcEIF3V (ORCPT ); Mon, 9 May 2016 01:29:21 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.24,599,1455004800"; d="scan'208";a="99625806" Date: Mon, 9 May 2016 08:29:17 +0300 From: Jarkko Sakkinen To: Jethro Beekman Cc: gregkh@linuxfoundation.org, "open list:STAGING SUBSYSTEM" , "maintainer:X86 ARCHITECTURE 32-BIT AND 64-BIT" , "open list:X86 ARCHITECTURE 32-BIT AND 64-BIT" , Ingo Molnar , "H. Peter Anvin" , Thomas Gleixner Subject: Re: [PATCH 3/6] intel_sgx: driver for Intel Secure Guard eXtensions Message-ID: <20160509052917.GA20120@intel.com> References: <1461605698-12385-1-git-send-email-jarkko.sakkinen@linux.intel.com> <1461605698-12385-4-git-send-email-jarkko.sakkinen@linux.intel.com> <57206102.3050507@jbeekman.nl> <20160427124056.GA22003@intel.com> <57214C07.8090806@jbeekman.nl> <20160429200449.GB27821@intel.com> <5723DE9B.7030102@jbeekman.nl> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5723DE9B.7030102@jbeekman.nl> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Apr 29, 2016 at 03:22:19PM -0700, Jethro Beekman wrote: > On 29-04-16 13:04, Jarkko Sakkinen wrote: > >>> Why would you want to do that? > >> > >> ... > > > > Do you see this as a performance issue or why do you think that this > > would hurt that much? > > I don't think it's a performance issue at all. I'm just giving an example of why > you'd want to do this. I'm sure people who want to use this instruction set can > come up with other uses, so I think the driver should support it. Other drivers > on different platform might support this, in which case we should be compatible > (to achieve the same enclave measurement). Other Linux drivers support it [1]. I > would ask: why would you not want to do this? It seems trivial to expand the > current flag into 16 separate flags; one for each 256-byte chunk in the page. I'm fine with adding a 16-bit bitmask. /Jarkko