From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Wed, 15 May 2019 14:43:05 +0200 From: Cornelia Huck 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> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: kvm-owner@vger.kernel.org List-Archive: List-Post: To: Eric Farman Cc: Farhan Ali , Halil Pasic , Pierre Morel , linux-s390@vger.kernel.org, kvm@vger.kernel.org List-ID: 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(-)