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=-2.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 2328AC33C9E for ; Tue, 28 Jan 2020 10:48:11 +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 E0E022467E for ; Tue, 28 Jan 2020 10:48:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="M7Xn4Zwy" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E0E022467E 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]:56846 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iwOPi-0007lW-28 for qemu-devel@archiver.kernel.org; Tue, 28 Jan 2020 05:48:10 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:51241) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iwOOu-00072g-Ns for qemu-devel@nongnu.org; Tue, 28 Jan 2020 05:47:24 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iwOOt-0001KA-Re for qemu-devel@nongnu.org; Tue, 28 Jan 2020 05:47:20 -0500 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:46828 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 1iwOOt-0001Jv-Oj for qemu-devel@nongnu.org; Tue, 28 Jan 2020 05:47:19 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1580208439; 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; bh=z43FRblCwedOjRZvSZiB/yhTk6UmQiFMUw8swuZX8Wo=; b=M7Xn4ZwyRb4NTUaBbx0AvgfdKFILtDOPE4KleJGR0m1Z8Y+e34lLIu0opbwiKwMdvKvbW3 pABQ8AHORTyGkmOvdofOkU0IIsTf3VGl3qbCoIE6vwRu8Iev92025zM3V/X2DhO7KeiaTG zZx5wI2zeke5Y+PoBHCkpOvJetstR6U= 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-301-2W3dnW85NyWrDNwJwjlzmQ-1; Tue, 28 Jan 2020 05:47:15 -0500 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 9181813E1; Tue, 28 Jan 2020 10:47:14 +0000 (UTC) Received: from [10.36.116.37] (ovpn-116-37.ams2.redhat.com [10.36.116.37]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 7E0AE1001B08; Tue, 28 Jan 2020 10:47:12 +0000 (UTC) To: qemu list , qemu-arm , Peter Maydell From: Auger Eric Subject: [question] hw/arm/virt: about the default gic-version in accelerated mode Message-ID: Date: Tue, 28 Jan 2020 11:47:09 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.4.0 MIME-Version: 1.0 Content-Language: en-US X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-MC-Unique: 2W3dnW85NyWrDNwJwjlzmQ-1 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 207.211.31.120 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: Andrew Jones , "Dr. David Alan Gilbert" Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Hi Peter, When arm virt machine is run in accelerated mode with "-cpu host -machine virt", the default gic version is 2. I understand the rationale with TCG where we don't have MSI ITS emulation along with GICv3 so we need to choose GICv2 to get GICv2M functionality. However in KVM mode, I would have expected to see the host GIC probed to set the same version on guest. Indeed most of our HW now have GICv3 without GICv2 compat mode so our default values lead to weird traces: " qemu-system-aarch64: PMU: KVM_SET_DEVICE_ATTR: Invalid argument qemu-system-aarch64: failed to set irq for PMU " I would like to propose a patch to improve those errors and also suggest a hint. But I also wanted to know whether you would accept to change the default value with KVM and choose the host version instead of 2. For TCG we would keep v2. Thanks Eric