From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752654AbdAUA3k (ORCPT ); Fri, 20 Jan 2017 19:29:40 -0500 Received: from wind.enjellic.com ([76.10.64.91]:38513 "EHLO wind.enjellic.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752556AbdAUA3i (ORCPT ); Fri, 20 Jan 2017 19:29:38 -0500 Date: Fri, 20 Jan 2017 18:29:33 -0600 From: "Dr. Greg Wettstein" Message-Id: <201701210029.v0L0TXdv031435@wind.enjellic.com> In-Reply-To: Boris Ostrovsky "Re: [PATCH] tpm: Restore functionality to xen vtpm driver." (Jan 20, 5:22pm) Reply-To: gw@idfusion.org X-Mailer: Mail User's Shell (7.2.6-ESD1.0 03/31/2012) To: Boris Ostrovsky , greg@enjellic.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH] tpm: Restore functionality to xen vtpm driver. Cc: dgdegra@tycho.nsa.gov, konrad.wilk@oracle.com, jarkko.sakkinen@linux.intel.com X-Greylist: Sender passed SPF test, not delayed by milter-greylist-4.2.3 (wind.enjellic.com [0.0.0.0]); Fri, 20 Jan 2017 18:29:33 -0600 (CST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Jan 20, 5:22pm, Boris Ostrovsky wrote: } Subject: Re: [PATCH] tpm: Restore functionality to xen vtpm driver. > On 01/20/2017 10:00 AM, Dr. Greg Wettstein wrote: > > Functionality of the xen-tpmfront driver was lost secondary to > > the introduction of xenbus multi-page support in the following > > commit: > > > > ccc9d90a9a8b5c4ad7e9708ec41f75ff9e98d61d > > > > xenbus_client: Extend interface to support multi-page ring > > > > In this commit a pointer to the shared page address was being > > passed to the xenbus_grant_ring() function rather then the > > address of the shared page itself. This resulted in a situation > > where the driver would attach to the vtpm-stubdom but any attempt > > to send a command to the stub domain would timeout. > > > > A diagnostic finding for this regression is the following error > > message being generated when the xen-tpmfront driver probes for a > > device: > > > > <3>vtpm vtpm-0: tpm_transmit: tpm_send: error -62 > > > > <3>vtpm vtpm-0: A TPM error (-62) occurred attempting to determine the timeouts > > > > This fix is relevant to all kernels from 4.1 forward which is the > > release in which multi-page xenbus support was introduced. > > > > Daniel De Graaf formulated the fix by code inspection after the > > regression point was located. > > > > Cc: # 4.1- > 4.1+, I believe. I thought the dash implied 4.1 forward but that may be my mis-understanding. In any event the patch should be applied to all stable kernels from 4.1 forward. We were lucky it wasn't anything more then a 1 character patch.... :-) Have a good weekend. Dr. Greg }-- End of excerpt from Boris Ostrovsky As always, Dr. G.W. Wettstein, Ph.D. Enjellic Systems Development, LLC. 4206 N. 19th Ave. Specializing in information infra-structure Fargo, ND 58102 development. PH: 701-281-1686 FAX: 701-281-3949 EMAIL: greg@enjellic.com ------------------------------------------------------------------------------ "This is a single non-reentrant routine which takes the received packet queue and throws it at the networking layers in the hope that something useful will emerge." -- dev.c, Linux Networking Sources --