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 BEE5EC43381 for ; Fri, 22 Feb 2019 22:14:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 950EE20675 for ; Fri, 22 Feb 2019 22:14:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725878AbfBVWOr (ORCPT ); Fri, 22 Feb 2019 17:14:47 -0500 Received: from mga17.intel.com ([192.55.52.151]:32327 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725774AbfBVWOq (ORCPT ); Fri, 22 Feb 2019 17:14:46 -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 fmsmga107.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 22 Feb 2019 14:14:45 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.58,401,1544515200"; d="scan'208";a="120092425" Received: from delmer-mobl.ger.corp.intel.com (HELO localhost) ([10.249.254.153]) by orsmga008.jf.intel.com with ESMTP; 22 Feb 2019 14:14:42 -0800 Date: Sat, 23 Feb 2019 00:14:42 +0200 From: Jarkko Sakkinen To: "Michael S. Tsirkin" Cc: Jason Gunthorpe , 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: <20190222221442.GA24082@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> <20190222215923.GB21427@linux.intel.com> <20190222170556-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190222170556-mutt-send-email-mst@kernel.org> 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 05:07:19PM -0500, Michael S. Tsirkin wrote: > On Fri, Feb 22, 2019 at 11:59:23PM +0200, Jarkko Sakkinen wrote: > > 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 > > I do this sometimes. One can't require samples for all supported > hardware. If I can check that code matches spec, I might settle for > that. What kind of specialized hardware this requires? /Jarkko