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=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 36217C5ACAE for ; Thu, 12 Sep 2019 08:58:21 +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 0BF1C2084F for ; Thu, 12 Sep 2019 08:58:21 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0BF1C2084F 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]:59370 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i8Kvk-0008SU-7J for qemu-devel@archiver.kernel.org; Thu, 12 Sep 2019 04:58:20 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:37975) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i8Kuj-0007Xn-Cn for qemu-devel@nongnu.org; Thu, 12 Sep 2019 04:57:18 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1i8Kui-0003jJ-F6 for qemu-devel@nongnu.org; Thu, 12 Sep 2019 04:57:17 -0400 Received: from mx1.redhat.com ([209.132.183.28]:34940) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1i8Kuf-0003iL-BR; Thu, 12 Sep 2019 04:57:13 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 577AF308212D; Thu, 12 Sep 2019 08:57:12 +0000 (UTC) Received: from [10.36.116.238] (ovpn-116-238.ams2.redhat.com [10.36.116.238]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 6E0985DA5B; Thu, 12 Sep 2019 08:57:10 +0000 (UTC) To: Peter Maydell References: <20190911155125.11932-1-eric.auger@redhat.com> <20190911155125.11932-4-eric.auger@redhat.com> From: Auger Eric Message-ID: <1b849672-31a6-3d8d-b8ea-254e737e3b80@redhat.com> Date: Thu, 12 Sep 2019 10:57:08 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.4.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.47]); Thu, 12 Sep 2019 08:57:12 +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] [RFC v2 3/3] virt: Check KVM_CAP_ARM_IRQ_LINE_LAYOUT_2 for smp_cpus > 256 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: Zenghui Yu , Marc Zyngier , qemu-arm , QEMU Developers , Eric Auger Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Hi Peter, On 9/12/19 10:42 AM, Peter Maydell wrote: > On Wed, 11 Sep 2019 at 16:51, Eric Auger wrote: >> >> Host kernel within [4.18, 5.3] report an erroneous KVM_MAX_VCPUS=512 >> for ARM. The actual capability to instantiate more than 256 vcpus >> was fixed in 5.4 with the upgrade of the KVM_IRQ_LINE ABI to support >> vcpu id encoded on 12 bits instead of 8 and a redistributor consuming >> a single KVM IO device instead of 2. >> >> So let's check this capability when attempting to use more than 256 >> vcpus. >> >> Signed-off-by: Eric Auger >> --- >> hw/arm/virt.c | 4 ++++ >> target/arm/kvm.c | 21 +++++++++++++++++++++ >> target/arm/kvm_arm.h | 15 +++++++++++++++ >> 3 files changed, 40 insertions(+) >> >> diff --git a/hw/arm/virt.c b/hw/arm/virt.c >> index 0d1629ccb3..465e3140f7 100644 >> --- a/hw/arm/virt.c >> +++ b/hw/arm/virt.c >> @@ -1575,6 +1575,10 @@ static void machvirt_init(MachineState *machine) >> virt_max_cpus = GIC_NCPU; >> } >> >> + if (kvm_arm_irq_line_layout_mismatch(MACHINE(vms), max_cpus)) { >> + exit(1); >> + } >> + > > Is there really no place to put this check in common code? Not sure what you mean by common code here? Do you mean in a common code for ARM machines (I don't think we have any atm) or directly in kvm_init(). I did not want to pollute this latter with this ARM specific fix. Thanks Eric > > thanks > -- PMM >