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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,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 8DDBEC433DB for ; Thu, 11 Mar 2021 15:53:04 +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 E98E964FBA for ; Thu, 11 Mar 2021 15:53:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E98E964FBA Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:47526 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lKNcU-0004t4-QP for qemu-devel@archiver.kernel.org; Thu, 11 Mar 2021 10:53:02 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:50860) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lKN7p-000341-Qg; Thu, 11 Mar 2021 10:21:21 -0500 Received: from mx2.suse.de ([195.135.220.15]:34988) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lKN7o-0004vL-1f; Thu, 11 Mar 2021 10:21:21 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 58502AB8C; Thu, 11 Mar 2021 15:21:18 +0000 (UTC) Subject: Re: arm: "max" CPU class hierarchy changes possible? To: Peter Maydell References: <11e9d3bb-c94c-4ad7-35b0-b698376c5e00@suse.de> From: Claudio Fontana Message-ID: Date: Thu, 11 Mar 2021 16:21:17 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.12.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=195.135.220.15; envelope-from=cfontana@suse.de; helo=mx2.suse.de X-Spam_score_int: -41 X-Spam_score: -4.2 X-Spam_bar: ---- X-Spam_report: (-4.2 / 5.0 requ) BAYES_00=-1.9, NICE_REPLY_A=-0.001, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action 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: Paolo Bonzini , =?UTF-8?Q?Philippe_Mathieu-Daud=c3=a9?= , qemu-arm , qemu-devel , Eduardo Habkost Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 3/11/21 4:02 PM, Peter Maydell wrote: > On Thu, 11 Mar 2021 at 14:27, Claudio Fontana wrote: >> the "max" cpu in x86 and s390 is a class, >> >> and then "host" has "max" as parent. >> >> This would be a convenient setup for ARM too, as it would allow to put common code between kvm and tcg in the "max" class, >> and allow "host" to specialize the behavior for KVM (and in the future HVF probably). >> >> Would changing the class hierarchy this way be acceptable, cause any problems? > > It's not clear to me why 'host' would be a subtype of 'max': > that doesn't seem like an obvious relationship. > > thanks > -- PMM If there is no blocker on _any_ change to the hierarchy I will put it in the RFC series, so we can discuss the merits there and investigate alternatives, if there is no immediate blocker to any change in the object hierarchy. https://lists.gnu.org/archive/html/qemu-devel/2021-03/msg03864.html Thanks, CLaudio