From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753183AbdATWX7 (ORCPT ); Fri, 20 Jan 2017 17:23:59 -0500 Received: from userp1050.oracle.com ([156.151.31.82]:30769 "EHLO userp1050.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752590AbdATWX5 (ORCPT ); Fri, 20 Jan 2017 17:23:57 -0500 Subject: Re: [PATCH] tpm: Restore functionality to xen vtpm driver. To: greg@enjellic.com, linux-kernel@vger.kernel.org References: <201701201500.v0KF02N1027871@wind.enjellic.com> Cc: dgdegra@tycho.nsa.gov, konrad.wilk@oracle.com, jarkko.sakkinen@linux.intel.com From: Boris Ostrovsky Message-ID: <6e0dd5d8-0aca-e85d-5f0a-5306e4f4ba16@oracle.com> Date: Fri, 20 Jan 2017 17:22:25 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.4.0 MIME-Version: 1.0 In-Reply-To: <201701201500.v0KF02N1027871@wind.enjellic.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-Source-IP: userp1040.oracle.com [156.151.31.81] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. > Suggested-by: Daniel De Graaf > Signed-off-by: Dr. Greg Wettstein Reviewed-by: Boris Ostrovsky > --- > drivers/char/tpm/xen-tpmfront.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/char/tpm/xen-tpmfront.c b/drivers/char/tpm/xen-tpmfront.c > index 3111f2778079..d1478f7b3f97 100644 > --- a/drivers/char/tpm/xen-tpmfront.c > +++ b/drivers/char/tpm/xen-tpmfront.c > @@ -201,7 +201,7 @@ static int setup_ring(struct xenbus_device *dev, struct tpm_private *priv) > return -ENOMEM; > } > > - rv = xenbus_grant_ring(dev, &priv->shr, 1, &gref); > + rv = xenbus_grant_ring(dev, priv->shr, 1, &gref); > if (rv < 0) > return rv; >