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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,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 7F864C04E53 for ; Wed, 15 May 2019 12:43:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4F7A52084E for ; Wed, 15 May 2019 12:43:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726578AbfEOMnI (ORCPT ); Wed, 15 May 2019 08:43:08 -0400 Received: from mx1.redhat.com ([209.132.183.28]:58324 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726392AbfEOMnI (ORCPT ); Wed, 15 May 2019 08:43:08 -0400 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 62B448046F; Wed, 15 May 2019 12:43:08 +0000 (UTC) Received: from gondolin (dhcp-192-222.str.redhat.com [10.33.192.222]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4F51060166; Wed, 15 May 2019 12:43:07 +0000 (UTC) Date: Wed, 15 May 2019 14:43:05 +0200 From: Cornelia Huck To: Eric Farman Cc: Farhan Ali , Halil Pasic , Pierre Morel , linux-s390@vger.kernel.org, kvm@vger.kernel.org Subject: Re: [PATCH v2 7/7] s390/cio: Remove vfio-ccw checks of command codes Message-ID: <20190515144305.46a2ecb1.cohuck@redhat.com> In-Reply-To: <20190514234248.36203-8-farman@linux.ibm.com> References: <20190514234248.36203-1-farman@linux.ibm.com> <20190514234248.36203-8-farman@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 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.28]); Wed, 15 May 2019 12:43:08 +0000 (UTC) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Wed, 15 May 2019 01:42:48 +0200 Eric Farman wrote: > If the CCW being processed is a No-Operation, then by definition no > data is being transferred. Let's fold those checks into the normal > CCW processors, rather than skipping out early. > > Likewise, if the CCW being processed is a "test" (an invented > definition to simply mean it ends in a zero), let's permit that to go > through to the hardware. There's nothing inherently unique about > those command codes versus one that ends in an eight [1], or any other > otherwise valid command codes that are undefined for the device type > in question. Hm... let's tweak that a bit? It's not that "test" is an invented category; it's just that this has not been a valid command for post-s/370 and therefore should not get any special treatment and just be sent to the hardware? > > [1] POPS states that a x08 is a TIC CCW, and that having any high-order > bits enabled is invalid for format-1 CCWs. For format-0 CCWs, the > high-order bits are ignored. > > Signed-off-by: Eric Farman > --- > drivers/s390/cio/vfio_ccw_cp.c | 11 +++++------ > 1 file changed, 5 insertions(+), 6 deletions(-)