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=-2.2 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 51086C352A2 for ; Thu, 6 Feb 2020 15:35:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2796122314 for ; Thu, 6 Feb 2020 15:35:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727457AbgBFPf0 (ORCPT ); Thu, 6 Feb 2020 10:35:26 -0500 Received: from mga03.intel.com ([134.134.136.65]:36383 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725535AbgBFPfZ (ORCPT ); Thu, 6 Feb 2020 10:35:25 -0500 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 06 Feb 2020 07:35:25 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,410,1574150400"; d="scan'208";a="432250596" Received: from dgbrowne-mobl.ger.corp.intel.com (HELO localhost) ([10.252.14.106]) by fmsmga006.fm.intel.com with ESMTP; 06 Feb 2020 07:35:20 -0800 Date: Thu, 6 Feb 2020 17:35:19 +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, 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, Serge Ayoun Subject: Re: [PATCH v25 07/21] x86/sgx: Enumerate and track EPC sections Message-ID: <20200206153519.GB9694@linux.intel.com> References: <20200204060545.31729-1-jarkko.sakkinen@linux.intel.com> <20200204060545.31729-8-jarkko.sakkinen@linux.intel.com> <20200205195700.GJ4877@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200205195700.GJ4877@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, Feb 05, 2020 at 11:57:00AM -0800, Sean Christopherson wrote: > 3. Breaks on-demand paging when running in a VM, e.g. if the VMM chooses > to allocate a physical EPC page when it's actually accessed by the > VM. I don't expect this to be a problem any time soon, as all VMMs > will likely preallocate EPC pages until KVM (or any other hypervisor) > gains EPC oversusbscription support, which may or may not ever happen. > But, I'd prefer to simply not have the problem in the first place. So wouldn't it be better to revisit this when the VM changes are added. /Jarkko