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_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 25C26CA9ECB for ; Thu, 31 Oct 2019 21:13:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E1DCE208E3 for ; Thu, 31 Oct 2019 21:13:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727630AbfJaVNE (ORCPT ); Thu, 31 Oct 2019 17:13:04 -0400 Received: from mga18.intel.com ([134.134.136.126]:37197 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727020AbfJaVNE (ORCPT ); Thu, 31 Oct 2019 17:13:04 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga106.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 31 Oct 2019 14:13:03 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.68,253,1569308400"; d="scan'208";a="194459648" Received: from epobrien-mobl1.ger.corp.intel.com (HELO localhost) ([10.252.10.103]) by orsmga008.jf.intel.com with ESMTP; 31 Oct 2019 14:12:53 -0700 Date: Thu, 31 Oct 2019 23:12:52 +0200 From: Jarkko Sakkinen To: Sean Christopherson Cc: linux-kernel@vger.kernel.org, x86@kernel.org, linux-sgx@vger.kernel.org, akpm@linux-foundation.org, dave.hansen@intel.com, nhorman@redhat.com, npmccallum@redhat.com, serge.ayoun@intel.com, shay.katz-zamir@intel.com, haitao.huang@intel.com, andriy.shevchenko@linux.intel.com, tglx@linutronix.de, kai.svahn@intel.com, bp@alien8.de, josh@joshtriplett.org, luto@kernel.org, kai.huang@intel.com, rientjes@google.com, cedric.xing@intel.com, puiterwijk@redhat.com, linux-security-module@vger.kernel.org, Suresh Siddha Subject: Re: [PATCH v23 12/24] x86/sgx: Linux Enclave Driver Message-ID: <20191031211252.GC10507@linux.intel.com> References: <20191028210324.12475-1-jarkko.sakkinen@linux.intel.com> <20191028210324.12475-13-jarkko.sakkinen@linux.intel.com> <20191029092920.GA14494@linux.intel.com> <20191030093045.GB12481@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191030093045.GB12481@linux.intel.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-sgx-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org On Wed, Oct 30, 2019 at 02:30:45AM -0700, Sean Christopherson wrote: > Why? The number of pages processed is effectively returned via the params > on any error, e.g. wouldn't it be more appropriate to return -ERESTARTSYS? > And I don't see any reason to add an arbitrary cap on the number of pages, > e.g. SGX plays nice with the scheduler and signals, and restricting the > number of EPC pages available to a process via cgroups (returning -ENOMEM) > is a better solution for managing EPC. Returning -ENOMEM does not tell you from which page to retry. /Jarkko