From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7EEA3C433FF for ; Thu, 8 Aug 2019 15:44:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5BA272173E for ; Thu, 8 Aug 2019 15:44:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733143AbfHHPo3 (ORCPT ); Thu, 8 Aug 2019 11:44:29 -0400 Received: from mga03.intel.com ([134.134.136.65]:54608 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732845AbfHHPo2 (ORCPT ); Thu, 8 Aug 2019 11:44:28 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 08 Aug 2019 08:44:28 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,362,1559545200"; d="scan'208";a="193179606" Received: from sandersb-mobl.ger.corp.intel.com (HELO localhost) ([10.249.33.239]) by fmsmga001.fm.intel.com with ESMTP; 08 Aug 2019 08:44:26 -0700 Date: Thu, 8 Aug 2019 18:44:24 +0300 From: Jarkko Sakkinen To: Sean Christopherson Cc: linux-sgx@vger.kernel.org, Shay Katz-zamir , Serge Ayoun Subject: Re: [PATCH for_v22 05/11] x86/sgx: Require EADD source to be page aligned Message-ID: <20190808154351.3jsh75ryezomussw@linux.intel.com> References: <20190808001254.11926-1-sean.j.christopherson@intel.com> <20190808001254.11926-6-sean.j.christopherson@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190808001254.11926-6-sean.j.christopherson@intel.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: NeoMutt/20180716 Sender: linux-sgx-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org On Wed, Aug 07, 2019 at 05:12:48PM -0700, Sean Christopherson wrote: > Reject the EADD ioctl() if the source address provided by userspace is > not page aligned. Page alignment is required by hardware, but this is > not enforced on userspace as the kernel first copies the source page to > an internal (page aligned) buffer. Require the userspace address to be > page aligned so that the driver can, in the future, directly consume the > userspace address via EADD without breaking backwards compatibility, > e.g. to avoid the overhead of alloc+memcpy. > > Signed-off-by: Sean Christopherson Not sure about this. Why not just implement a fast path when the address is aligned (in future)? /Jarkko