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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 B6BB4C606B0 for ; Tue, 9 Jul 2019 09:57:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8F2482080C for ; Tue, 9 Jul 2019 09:57:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726666AbfGIJ5i (ORCPT ); Tue, 9 Jul 2019 05:57:38 -0400 Received: from mx1.redhat.com ([209.132.183.28]:57038 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726126AbfGIJ5i (ORCPT ); Tue, 9 Jul 2019 05:57:38 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 6516519CF51; Tue, 9 Jul 2019 09:57:38 +0000 (UTC) Received: from gondolin (unknown [10.40.205.62]) by smtp.corp.redhat.com (Postfix) with ESMTP id ECCF35DA97; Tue, 9 Jul 2019 09:57:36 +0000 (UTC) Date: Tue, 9 Jul 2019 11:57:33 +0200 From: Cornelia Huck To: Farhan Ali Cc: farman@linux.ibm.com, pasic@linux.ibm.com, linux-s390@vger.kernel.org, kvm@vger.kernel.org Subject: Re: [RFC v2 1/5] vfio-ccw: Fix misleading comment when setting orb.cmd.c64 Message-ID: <20190709115733.40eb8db5.cohuck@redhat.com> In-Reply-To: <25a5bf8ae538a392f8483e6fd4b9b165de40bfce.1562616169.git.alifm@linux.ibm.com> References: <25a5bf8ae538a392f8483e6fd4b9b165de40bfce.1562616169.git.alifm@linux.ibm.com> Organization: Red Hat GmbH MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Tue, 09 Jul 2019 09:57:38 +0000 (UTC) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Mon, 8 Jul 2019 16:10:34 -0400 Farhan Ali wrote: > The comment is misleading because it tells us that > we should set orb.cmd.c64 before calling ccwchain_calc_length, > otherwise the function ccwchain_calc_length would return an > error. This is not completely accurate. > > We want to allow an orb without cmd.c64, and this is fine > as long as the channel program does not use IDALs. But we do > want to reject any channel program that uses IDALs and does > not set the flag, which what we do in ccwchain_calc_length. > > After we have done the ccw processing, it should be safe > to set cmd.c64, since we will convert them into IDALs. "After we have done the ccw processing, we need to set cmd.c64, as we use IDALs for all translated channel programs." ? > Fixes: fb9e7880af35 ("vfio: ccw: push down unsupported IDA check") > Signed-off-by: Farhan Ali > --- > drivers/s390/cio/vfio_ccw_cp.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/s390/cio/vfio_ccw_cp.c b/drivers/s390/cio/vfio_ccw_cp.c > index d6a8dff..7622b72 100644 > --- a/drivers/s390/cio/vfio_ccw_cp.c > +++ b/drivers/s390/cio/vfio_ccw_cp.c > @@ -645,8 +645,8 @@ int cp_init(struct channel_program *cp, struct device *mdev, union orb *orb) > if (ret) > cp_free(cp); > > - /* It is safe to force: if not set but idals used > - * ccwchain_calc_length returns an error. > + /* It is safe to force: if it was not set but idals used > + * ccwchain_calc_length would have returned an error. Thanks, much clearer. > */ > cp->orb.cmd.c64 = 1; > Reviewed-by: Cornelia Huck