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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 0D2DBC48BD3 for ; Wed, 26 Jun 2019 12:24:42 +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 D436C204FD for ; Wed, 26 Jun 2019 12:24:41 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D436C204FD 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]:39668 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hg6yf-00088D-4o for qemu-devel@archiver.kernel.org; Wed, 26 Jun 2019 08:24:41 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:50654) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hg6pd-00015r-Mm for qemu-devel@nongnu.org; Wed, 26 Jun 2019 08:15:22 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hg6pc-0008Cf-GI for qemu-devel@nongnu.org; Wed, 26 Jun 2019 08:15:21 -0400 Received: from mx1.redhat.com ([209.132.183.28]:46748) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hg6pc-0006OX-9M; Wed, 26 Jun 2019 08:15:20 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id F1ACD307D945; Wed, 26 Jun 2019 12:14:32 +0000 (UTC) Received: from gondolin (dhcp-192-222.str.redhat.com [10.33.192.222]) by smtp.corp.redhat.com (Postfix) with ESMTP id C30465C1A1; Wed, 26 Jun 2019 12:14:25 +0000 (UTC) Date: Wed, 26 Jun 2019 14:14:23 +0200 From: Cornelia Huck To: Christian Borntraeger Message-ID: <20190626141423.0bbd86eb.cohuck@redhat.com> In-Reply-To: References: <1561475829-19202-1-git-send-email-walling@linux.ibm.com> <1561475829-19202-3-git-send-email-walling@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 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.48]); Wed, 26 Jun 2019 12:14:38 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: Re: [Qemu-devel] [PATCH v5 2/2] s390: diagnose 318 info reset and migration support 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: Collin Walling , david@redhat.com, mst@redhat.com, qemu-devel@nongnu.org, pasic@linux.ibm.com, qemu-s390x@nongnu.org, pbonzini@redhat.com, rth@twiddle.net Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Wed, 26 Jun 2019 11:12:04 +0200 Christian Borntraeger wrote: > On 25.06.19 17:17, Collin Walling wrote: > > index a606547..4c26754 100644 > > --- a/target/s390x/cpu.h > > +++ b/target/s390x/cpu.h > > @@ -39,7 +39,13 @@ > > > > #define MMU_USER_IDX 0 > > > > -#define S390_MAX_CPUS 248 > > +/* > > + * HACK: The introduction of additional facility bytes in the Read Info > > + * struct consumes space used for CPU entries, thus we must reduce the > > + * original maximum CPUs of 248 by one for each new byte or risk smashing > > + * the stack. > > + */ > > +#define S390_MAX_CPUS 247 > > I think we decided to not change that. Only if the cpu model contains the diag318 > feature we are limited to 247 but only for the sclp response. > So we said: > - we continue to allow 248 cpus > - the sclp response will be limited to 247 CPUs if the feature is one > - (optional) we print a warning that the guest might not see all CPUs > Yes, that's what I remember as well... and printing/logging a warning is a good idea.