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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 1BB86C43387 for ; Sun, 23 Dec 2018 20:43:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D2B47217D7 for ; Sun, 23 Dec 2018 20:43:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1545597782; bh=XWloAgP0FimDnwcL2BUy6GJT3cfzyDOhnds0UkaNybQ=; h=References:In-Reply-To:From:Date:Subject:To:Cc:List-ID:From; b=KnJjgQV2OeSkKgdkKHStrEJMVn/83jLUjWNLj7mVwrgB288ej+ZCzYujF86xAJh6e 22JA2BI/PIkqK95pjSaZyOrzDsg82t0We1FnxZ1ieaAN7Fo+cIp4wicrxQdGZcV8HX H7pToC8MFK/oSrL6eCQyJ/hgGQEmYSMzKikPEE/Q= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725872AbeLWUnC (ORCPT ); Sun, 23 Dec 2018 15:43:02 -0500 Received: from mail.kernel.org ([198.145.29.99]:43958 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725831AbeLWUnC (ORCPT ); Sun, 23 Dec 2018 15:43:02 -0500 Received: from mail-wm1-f43.google.com (mail-wm1-f43.google.com [209.85.128.43]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B0C2F218D8 for ; Sun, 23 Dec 2018 20:43:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1545597781; bh=XWloAgP0FimDnwcL2BUy6GJT3cfzyDOhnds0UkaNybQ=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=YnxwSVxWl05U9WKyzfP3iXJFV9jtY01GKPVmSqO9P5sC0XB7r2T6tZu4M3D3tg1vM czmdxw/lw9QjtNYQdT6x0EuHbV0C9YDPFZtQ2oSw8U2xf5hq45aI9DZY2ZT91gLBWB TWXrwqoFRGHrdPIlrEk9++5MJ5i9KCIms+w174xE= Received: by mail-wm1-f43.google.com with SMTP id b11so9867297wmj.1 for ; Sun, 23 Dec 2018 12:43:00 -0800 (PST) X-Gm-Message-State: AJcUukeWuqaNc9pb8HnKVaTx56H75Buu8cAElNHfnR4bKXbgC+UT3Z2v 2OEEs3r3BLtT9Arr80POQfsYvcilTiS7uiFLsh1OAw== X-Google-Smtp-Source: AFSGD/XlkK/oNtDFZc+Wje5CTyDu6DUBEjhrkmj9Ddr2xiLcOY1DOQZTFnMEkmAKsEEEiLADF4Lqk+AgUrrl0RNWB+A= X-Received: by 2002:a1c:aa0f:: with SMTP id t15mr9809530wme.108.1545597779143; Sun, 23 Dec 2018 12:42:59 -0800 (PST) MIME-Version: 1.0 References: <20181214215729.4221-1-sean.j.christopherson@intel.com> <7706b2aa71312e1f0009958bcab24e1e9d8d1237.camel@linux.intel.com> <598cd050-f0b5-d18c-96a0-915f02525e3e@fortanix.com> <20181219091148.GA5121@linux.intel.com> <613c6814-4e71-38e5-444a-545f0e286df8@fortanix.com> <20181219144515.GA30909@linux.intel.com> <20181220103204.GB26410@linux.intel.com> <20181222081649.GB8895@linux.intel.com> <20181222082502.GA13275@linux.intel.com> <20181223125114.GA7051@linux.intel.com> In-Reply-To: <20181223125114.GA7051@linux.intel.com> From: Andy Lutomirski Date: Sun, 23 Dec 2018 12:42:48 -0800 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: x86/sgx: uapi change proposal To: Jarkko Sakkinen Cc: Andy Lutomirski , Sean Christopherson , Jethro Beekman , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "x86@kernel.org" , Dave Hansen , Peter Zijlstra , "H. Peter Anvin" , "linux-kernel@vger.kernel.org" , "linux-sgx@vger.kernel.org" , Josh Triplett , Haitao Huang , "Dr . Greg Wettstein" Content-Type: text/plain; charset="UTF-8" Sender: linux-sgx-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org On Sun, Dec 23, 2018 at 4:52 AM Jarkko Sakkinen wrote: > > On Sat, Dec 22, 2018 at 10:25:02AM +0200, Jarkko Sakkinen wrote: > > On Sat, Dec 22, 2018 at 10:16:49AM +0200, Jarkko Sakkinen wrote: > > > On Thu, Dec 20, 2018 at 12:32:04PM +0200, Jarkko Sakkinen wrote: > > > > On Wed, Dec 19, 2018 at 06:58:48PM -0800, Andy Lutomirski wrote: > > > > > Can one of you explain why SGX_ENCLAVE_CREATE is better than just > > > > > opening a new instance of /dev/sgx for each encalve? > > > > > > > > I think that fits better to the SCM_RIGHTS scenario i.e. you could send > > > > the enclav to a process that does not have necessarily have rights to > > > > /dev/sgx. Gives more robust environment to configure SGX. > > > > > > Sean, is this why you wanted enclave fd and anon inode and not just use > > > the address space of /dev/sgx? Just taking notes of all observations. > > > I'm not sure what your rationale was (maybe it was somewhere). This was > > > something I made up, and this one is wrong deduction. You can easily > > > get the same benefit with /dev/sgx associated fd representing the > > > enclave. > > > > > > This all means that for v19 I'm going without enclave fd involved with > > > fd to /dev/sgx representing the enclave. No anon inodes will be > > > involved. > > > > Based on these observations I updated the uapi. > > > > As far as I'm concerned there has to be a solution to do EPC mapping > > with a sequence: > > > > 1. Ping /dev/kvm to do something. > > 2. KVM asks SGX core to do something. > > 3. SGX core does something. > > > > I don't care what the something is exactly is, but KVM is the only sane > > place for KVM uapi. I would be surprised if KVM maintainers didn't agree > > that they don't want to sprinkle KVM uapi to random places in other > > subsystems. > > The one option to consider to do would be to have a device driver for > KVM if you really want this e.g. something like /dev/vsgx. With the > current knowledge I'm not yet sure why all could not be done just > through /dev/kvm. > That seems reasonable too. I don't really care about the path to the device node, but it does seem reasonable to me to have it be a separate node entirely from the normal enclave interface.