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=-2.5 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 D3AE1C43387 for ; Tue, 18 Dec 2018 01:39:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 98BD02080D for ; Tue, 18 Dec 2018 01:39:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726301AbeLRBjc (ORCPT ); Mon, 17 Dec 2018 20:39:32 -0500 Received: from mga01.intel.com ([192.55.52.88]:9821 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726285AbeLRBjc (ORCPT ); Mon, 17 Dec 2018 20:39:32 -0500 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 fmsmga101.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 17 Dec 2018 17:39:31 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.56,367,1539673200"; d="scan'208";a="102304869" Received: from unknown (HELO localhost) ([10.249.254.218]) by orsmga008.jf.intel.com with ESMTP; 17 Dec 2018 17:39:19 -0800 Date: Tue, 18 Dec 2018 03:39:18 +0200 From: Jarkko Sakkinen To: Sean Christopherson Cc: Andy Lutomirski , Dave Hansen , X86 ML , Platform Driver , linux-sgx@vger.kernel.org, nhorman@redhat.com, npmccallum@redhat.com, "Ayoun, Serge" , shay.katz-zamir@intel.com, Haitao Huang , Andy Shevchenko , Thomas Gleixner , "Svahn, Kai" , mark.shanahan@intel.com, Suresh Siddha , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , Darren Hart , Andy Shevchenko , "open list:X86 ARCHITECTURE (32-BIT AND 64-BIT)" Subject: Re: [PATCH v17 18/23] platform/x86: Intel SGX driver Message-ID: <20181218013918.GC333@linux.intel.com> References: <20181116010412.23967-1-jarkko.sakkinen@linux.intel.com> <20181116010412.23967-19-jarkko.sakkinen@linux.intel.com> <7d5cde02-4649-546b-0f03-2d6414bb80b5@intel.com> <20181217180102.GA12560@linux.intel.com> <20181217183613.GD12491@linux.intel.com> <20181217184333.GA26920@linux.intel.com> <20181217222047.GG12491@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181217222047.GG12491@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 Mon, Dec 17, 2018 at 02:20:48PM -0800, Sean Christopherson wrote: > The only potential hiccup I can see is the build flow. Currently, > EADD+EEXTEND is done via a work queue to avoid major performance issues > (10x regression) when userspace is building multiple enclaves in parallel > using goroutines to wrap Cgo (the issue might apply to any M:N scheduler, > but I've only confirmed the Golang case). The issue is that allocating > an EPC page acts like a blocking syscall when the EPC is under pressure, > i.e. an EPC page isn't immediately available. This causes Go's scheduler > to thrash and tank performance[1]. I don't see any major issues having that kthread. All the code that maps the enclave would be removed. I would only allow to map enclave to process address space after the enclave has been initialized i.e. SGX_IOC_ENCLAVE_ATTACH. /Jarkko