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=-6.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, 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 A20F4C35E01 for ; Tue, 25 Feb 2020 14:48:55 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 6DA422064A for ; Tue, 25 Feb 2020 14:48:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Hc190EdT" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6DA422064A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:58078 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j6bW2-0003vV-IE for qemu-devel@archiver.kernel.org; Tue, 25 Feb 2020 09:48:54 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:51837) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j6bVI-0003Sz-JY for qemu-devel@nongnu.org; Tue, 25 Feb 2020 09:48:09 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1j6bVG-0004Jv-UV for qemu-devel@nongnu.org; Tue, 25 Feb 2020 09:48:08 -0500 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:42689 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1j6bVF-0004Iz-PA for qemu-devel@nongnu.org; Tue, 25 Feb 2020 09:48:06 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1582642084; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=dt8sAbNbRoJwVElkyjF1TwUhGRgiM4ixeDE8DWOKqns=; b=Hc190EdTupnHA9ojHNWtf0o7NbFMLg0Efw4nl9wgQj28Bk3UK7fILdXw5e0YGWq+Lt8czd Mm5zgvyJoYruahIm7yNrXAc7kNz4naa4wFypPeljBN79o1OWVDVh9L16OMj8nk1sKMFySS SziywHcW2EkXr+b7w+K/ARGwA2dzR8s= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-64-Txe_mafxN5iMb6W0a-kGAg-1; Tue, 25 Feb 2020 09:48:00 -0500 X-MC-Unique: Txe_mafxN5iMb6W0a-kGAg-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 26A5B800D53; Tue, 25 Feb 2020 14:47:57 +0000 (UTC) Received: from gondolin (dhcp-192-175.str.redhat.com [10.33.192.175]) by smtp.corp.redhat.com (Postfix) with ESMTP id B25498ED01; Tue, 25 Feb 2020 14:47:52 +0000 (UTC) Date: Tue, 25 Feb 2020 15:47:50 +0100 From: Cornelia Huck To: Viktor Mihajlovski Subject: Re: [PATCH 1/1] s390/ipl: sync back loadparm Message-ID: <20200225154750.6bee1c52.cohuck@redhat.com> In-Reply-To: <853387e3-4425-731b-bb09-a7210ea6b299@linux.ibm.com> References: <20200224150213.21253-1-pasic@linux.ibm.com> <05f7dcf7-a0c7-8811-6b88-df86d5fa0974@redhat.com> <20200225125641.72e8cc86.pasic@linux.ibm.com> <853387e3-4425-731b-bb09-a7210ea6b299@linux.ibm.com> Organization: Red Hat GmbH MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 205.139.110.120 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Thomas Huth , Janosch Frank , David Hildenbrand , qemu-devel@nongnu.org, Halil Pasic , Christian Borntraeger , qemu-s390x@nongnu.org, Marc Hartmayer , Richard Henderson Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Tue, 25 Feb 2020 15:35:47 +0100 Viktor Mihajlovski wrote: > On 2/25/20 12:56 PM, Halil Pasic wrote: > > On Tue, 25 Feb 2020 10:39:40 +0100 > > David Hildenbrand wrote: > > > >> On 24.02.20 16:02, Halil Pasic wrote: > >>> We expose loadparm as a r/w machine property, but if loadparm is set by > >>> the guest via DIAG 308, we don't update the property. Having a > >>> disconnect between the guest view and the QEMU property is not nice in > >>> itself, but things get even worse for SCSI, where under certain > >>> circumstances (see 789b5a401b "s390: Ensure IPL from SCSI works as > >>> expected" for details) we call s390_gen_initial_iplb() on resets > >>> effectively overwriting the guest/user supplied loadparm with the stale > >>> value. > >>> > >>> Signed-off-by: Halil Pasic > >>> Fixes: 7104bae9de "hw/s390x: provide loadparm property for the machine" Please use the format Fixes: ("subject") > >>> Reported-by: Marc Hartmayer > >>> Reviewed-by: Janosch Frank > >>> Reviewed-by: Viktor Mihajlovski > >>> Tested-by: Marc Hartmayer > >>> --- > >>> hw/s390x/ipl.c | 21 +++++++++++++++++++++ > >>> 1 file changed, 21 insertions(+) > >>> > >>> diff --git a/hw/s390x/ipl.c b/hw/s390x/ipl.c > [...] > >>> + > >>> + /* Sync loadparm */ > >>> + if (iplb->flags & DIAG308_FLAGS_LP_VALID) { > >>> + char ascii_loadparm[8]; > >>> + uint8_t *ebcdic_loadparm = iplb->loadparm; > >>> + int i; > >>> + > >>> + for (i = 0; i < 8 && ebcdic_loadparm[i]; i++) { > >>> + ascii_loadparm[i] = ebcdic2ascii[(uint8_t) ebcdic_loadparm[i]]; > >>> + } > >>> + ascii_loadparm[i] = 0; > >>> + object_property_set_str(mo, ascii_loadparm, "loadparm", NULL); > >>> + } else { > >>> + object_property_set_str(mo, "", "loadparm", NULL); > >>> + } > >> > >> &error_abort instead of NULL, we certainly want to know if this would > >> ever surprisingly fail. > > > > IMHO this is a typical assert() situation where one would like to have > > a fast and obvious failure when testing, but not in production. > > > > AFAIU the guest can trigger this code at any time, and crashing the > > whole (production) system seems a bit heavy handed to me. The setter > > should only fail if something is buggy. > > > > But if the majority says &error_abort I can certainly do. Other opinions? > > > We might consider to return 0x0402 (invalid parameter) from the diag308 > "set", which is less drastic and would allow the OS to do whatever it > finds appropriate to deal with the failure. Not that Linux would care > about that today :-). I'm not sure if we could actually get there in any other way than via a QEMU coding error... not sure if I would trust QEMU to inject a return code if it already had a code logic fail right before that :)