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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 E9086C43143 for ; Tue, 2 Oct 2018 00:07:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A953E21471 for ; Tue, 2 Oct 2018 00:07:38 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A953E21471 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726518AbeJBGrz (ORCPT ); Tue, 2 Oct 2018 02:47:55 -0400 Received: from mga07.intel.com ([134.134.136.100]:57680 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725936AbeJBGry (ORCPT ); Tue, 2 Oct 2018 02:47:54 -0400 X-Amp-Result: UNSCANNABLE X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga105.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 01 Oct 2018 17:07:34 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.54,329,1534834800"; d="scan'208";a="267594305" Received: from hubermic-mobl.ger.corp.intel.com (HELO localhost) ([10.252.54.31]) by fmsmga005.fm.intel.com with ESMTP; 01 Oct 2018 17:07:27 -0700 Date: Tue, 2 Oct 2018 03:07:25 +0300 From: Jarkko Sakkinen To: Sean Christopherson Cc: Andy Lutomirski , Dave Hansen , Andrew Lutomirski , X86 ML , Platform Driver , nhorman@redhat.com, npmccallum@redhat.com, "Ayoun, Serge" , shay.katz-zamir@intel.com, linux-sgx@vger.kernel.org, Andy Shevchenko , Dave Hansen , Peter Zijlstra , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , LKML Subject: Re: [PATCH v14 09/19] x86/mm: x86/sgx: Signal SEGV_SGXERR for #PFs w/ PF_SGX Message-ID: <20181002000725.GB21814@linux.intel.com> References: <20180925130845.9962-1-jarkko.sakkinen@linux.intel.com> <20180925130845.9962-10-jarkko.sakkinen@linux.intel.com> <20180926173516.GA10920@linux.intel.com> <2D60780F-ADB4-48A4-AB74-15683493D369@amacapital.net> <9835e288-ba98-2f9e-ac73-504db9512bb9@intel.com> <20180926204400.GA11446@linux.intel.com> <1538404143.30715.27.camel@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1538404143.30715.27.camel@intel.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Oct 01, 2018 at 07:29:03AM -0700, Sean Christopherson wrote: > On Wed, 2018-09-26 at 14:15 -0700, Andy Lutomirski wrote: > > runs an enclave an returns an error code, and rig up the #PF handler > > to check if the error happened in the vDSO entry and fix it up rather > > than sending a signal? > > > If we want to avoid having to install a signal handler then I'm pretty > sure we'd need to fixup all #GPs and "bad access" #PFs that occur on > EENTER or in the enclave, not just PF_SGX faults.  SGX1 hardware takes > a #GP instead of a #PF on EPCM faults, and SGX2 hardware allows enclaves > to allocate/free/adjust EPC pages at runtime, e.g. an enclave runtime > might want to intercept #PFs from within the enclave so that the enclave > can dynamically grow its stack. If I've understood Andy's proposal correctly, the run-time would get the same information as with a signal. The delivery path for this information would be just different. /Jarkko