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 2D7D0C43381 for ; Fri, 22 Feb 2019 21:59:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EF24F20675 for ; Fri, 22 Feb 2019 21:59:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726287AbfBVV71 (ORCPT ); Fri, 22 Feb 2019 16:59:27 -0500 Received: from mga09.intel.com ([134.134.136.24]:33850 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726116AbfBVV71 (ORCPT ); Fri, 22 Feb 2019 16:59:27 -0500 X-Amp-Result: UNSCANNABLE X-Amp-File-Uploaded: False Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 22 Feb 2019 13:59:26 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.58,401,1544515200"; d="scan'208";a="145787279" Received: from delmer-mobl.ger.corp.intel.com (HELO localhost) ([10.249.254.153]) by fmsmga002.fm.intel.com with ESMTP; 22 Feb 2019 13:59:22 -0800 Date: Fri, 22 Feb 2019 23:59:23 +0200 From: Jarkko Sakkinen To: Jason Gunthorpe Cc: "Michael S. Tsirkin" , James Bottomley , David Tolnay , Peter Huewe , linux-integrity@vger.kernel.org, Jason Wang , virtualization@lists.linux-foundation.org, dgreid@chromium.org, apronin@chromium.org Subject: Re: [PATCH] tpm: Add driver for TPM over virtio Message-ID: <20190222215923.GB21427@linux.intel.com> References: <388c5b80-21a7-1e91-a11f-3a1c1432368b@gmail.com> <1550849416.2787.5.camel@HansenPartnership.com> <20190222160220-mutt-send-email-mst@kernel.org> <20190222213137.GZ17500@ziepe.ca> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190222213137.GZ17500@ziepe.ca> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-integrity-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org On Fri, Feb 22, 2019 at 02:31:37PM -0700, Jason Gunthorpe wrote: > On Fri, Feb 22, 2019 at 04:16:01PM -0500, Michael S. Tsirkin wrote: > > On Fri, Feb 22, 2019 at 07:30:16AM -0800, James Bottomley wrote: > > > On Thu, 2019-02-21 at 18:14 -0800, David Tolnay wrote: > > > > Add a config TCG_VIRTIO_VTPM which enables a driver providing the > > > > guest kernel side of TPM over virtio. > > > > > > What's the use case for using this over the current non-virtio vTPM?. > > > I always thought virtio was about guest to host transport efficiency, > > > but the phsical TPM, being connected over a very slow bus, is about as > > > inefficient as you can get in that regard, so why do we need to use > > > virtio to drive the virtual one? > > > > I can't say for sure about TPM. > > > > But generally there are many reasons to do virtio rather than emulating > > a hardware device. > > We already have a xen 'virtioish' TPM driver, so I don't think there > is a good reason to block a virtio driver if someone cares about > it. There are enough good reasons to prefer virtio to other options, > IMHO. > > Provided it meets the general requirements for new virtio stuff you > outlined. Yeah, absolutely we can consider this. For me it boils down to testing and documentation part. No plans to merge code that I'm unable to run... /Jarkko