From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:55197 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726889AbgEOIZ4 (ORCPT ); Fri, 15 May 2020 04:25:56 -0400 Date: Fri, 15 May 2020 10:25:48 +0200 From: Cornelia Huck Subject: Re: [kvm-unit-tests PATCH v6 07/10] s390x: css: msch, enable test Message-ID: <20200515102548.0f43419d.cohuck@redhat.com> In-Reply-To: References: <1587725152-25569-1-git-send-email-pmorel@linux.ibm.com> <1587725152-25569-8-git-send-email-pmorel@linux.ibm.com> <20200514140808.269f6485.cohuck@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-s390-owner@vger.kernel.org List-ID: To: Pierre Morel Cc: Janosch Frank , kvm@vger.kernel.org, linux-s390@vger.kernel.org, david@redhat.com, thuth@redhat.com On Fri, 15 May 2020 09:11:52 +0200 Pierre Morel wrote: > On 2020-05-14 14:08, Cornelia Huck wrote: > > On Tue, 28 Apr 2020 10:27:36 +0200 > > Pierre Morel wrote: > > > >> On 2020-04-27 15:11, Janosch Frank wrote: > >>> On 4/24/20 12:45 PM, Pierre Morel wrote: > > > >>>> This is NOT a routine to really enable the channel, no retry is done, > >>>> in case of error, a report is made. > >>> > >>> Would we expect needing retries for the pong device? > >> > >> Yes it can be that we need to retry some instructions if we want them to > >> succeed. > >> This is the case for example if we develop a driver for an operating system. > >> When working with firmware, sometime, things do not work at the first > >> time. Mostly due to races in silicium, firmware or hypervisor or between > >> them all. > >> > >> Since our purpose is to detect such problems we do not retry > >> instructions but report the error. > >> > >> If we detect such problem we may in the future enhance the tests. > > > > I think I've seen retries needed on z/VM in the past; do you know if > > that still happens? > > > > I did not try the tests under z/VM, nor direct on an LPAR, only under > QEMU/KVM. > Under QEMU/KVM, I did not encounter any need for retry, 100% of the > enabled succeeded on first try. Yep, QEMU/KVM should be fine. Do you plan to run this on anything else?