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=-7.0 required=3.0 tests=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 70545C49ED7 for ; Fri, 13 Sep 2019 09:58:31 +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 39CA320717 for ; Fri, 13 Sep 2019 09:58:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 39CA320717 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]:41918 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i8iLW-0001CK-52 for qemu-devel@archiver.kernel.org; Fri, 13 Sep 2019 05:58:30 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:58516) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i8iK1-0008Is-Ei for qemu-devel@nongnu.org; Fri, 13 Sep 2019 05:56:58 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1i8iK0-0007Nr-FN for qemu-devel@nongnu.org; Fri, 13 Sep 2019 05:56:57 -0400 Received: from mx1.redhat.com ([209.132.183.28]:51016) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1i8iJy-0007Mv-Bp; Fri, 13 Sep 2019 05:56:54 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 9FA72300C72B; Fri, 13 Sep 2019 09:56:53 +0000 (UTC) Received: from laptop.redhat.com (ovpn-116-33.ams2.redhat.com [10.36.116.33]) by smtp.corp.redhat.com (Postfix) with ESMTP id DB97960C44; Fri, 13 Sep 2019 09:56:51 +0000 (UTC) From: Eric Auger To: eric.auger.pro@gmail.com, eric.auger@redhat.com, qemu-devel@nongnu.org, qemu-arm@nongnu.org, peter.maydell@linaro.org Date: Fri, 13 Sep 2019 11:56:39 +0200 Message-Id: <20190913095639.25447-4-eric.auger@redhat.com> In-Reply-To: <20190913095639.25447-1-eric.auger@redhat.com> References: <20190913095639.25447-1-eric.auger@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.45]); Fri, 13 Sep 2019 09:56:53 +0000 (UTC) Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [RFC v3 3/3] ARM: KVM: 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: yuzenghui@huawei.com, maz@kernel.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Host kernel within [4.18, 5.3] report an erroneous KVM_MAX_VCPUS=3D512 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 within any ARM kvm accelerated machine. Signed-off-by: Eric Auger --- v2 -> v3: - Implement the check in kvm_arch_init as suggested by Peter --- target/arm/kvm.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/target/arm/kvm.c b/target/arm/kvm.c index b10581fa06..b473c63edb 100644 --- a/target/arm/kvm.c +++ b/target/arm/kvm.c @@ -182,6 +182,7 @@ int kvm_arm_get_max_vm_ipa_size(MachineState *ms) =20 int kvm_arch_init(MachineState *ms, KVMState *s) { + int ret =3D 0; /* For ARM interrupt delivery is always asynchronous, * whether we are using an in-kernel VGIC or not. */ @@ -195,7 +196,14 @@ int kvm_arch_init(MachineState *ms, KVMState *s) =20 cap_has_mp_state =3D kvm_check_extension(s, KVM_CAP_MP_STATE); =20 - return 0; + if (ms->smp.cpus > 256 && + !kvm_check_extension(s, KVM_CAP_ARM_IRQ_LINE_LAYOUT_2)) { + error_report("Using more than 256 vcpus requires a host kernel " + "with KVM_CAP_ARM_IRQ_LINE_LAYOUT_2"); + ret =3D -EINVAL; + } + + return ret; } =20 unsigned long kvm_arch_vcpu_id(CPUState *cpu) --=20 2.20.1