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,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 4C7C1C433DB for ; Thu, 18 Mar 2021 12:44:43 +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 B025764F04 for ; Thu, 18 Mar 2021 12:44:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B025764F04 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]:43720 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lMs13-0005Fi-Hw for qemu-devel@archiver.kernel.org; Thu, 18 Mar 2021 08:44:41 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:60312) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lMrz7-0004Ee-Qv; Thu, 18 Mar 2021 08:42:41 -0400 Received: from mx2.suse.de ([195.135.220.15]:56986) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lMrz6-0001IZ-43; Thu, 18 Mar 2021 08:42:41 -0400 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 DAF5DAC1F; Thu, 18 Mar 2021 12:42:37 +0000 (UTC) Subject: Re: arm_cpu_post_init (Was: Re: arm: "max" CPU class hierarchy changes possible?) To: Andrew Jones References: <11e9d3bb-c94c-4ad7-35b0-b698376c5e00@suse.de> <2e6a5d98-e022-0b39-5f30-92eb74491d3b@redhat.com> <2277fdf5-ec92-476a-8fe5-0d4eee23dfef@suse.de> <20210311191046.ykcelkwq7orajyu7@kamzik.brq.redhat.com> <5467e45c-cc8e-6422-0c56-398405a7c331@suse.de> <20210318120837.cg4gfdpchjwiabav@kamzik.brq.redhat.com> From: Claudio Fontana Message-ID: Date: Thu, 18 Mar 2021 13:42:36 +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: <20210318120837.cg4gfdpchjwiabav@kamzik.brq.redhat.com> 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: Peter Maydell , Eduardo Habkost , Richard Henderson , =?UTF-8?Q?Philippe_Mathieu-Daud=c3=a9?= , qemu-devel , qemu-arm , Paolo Bonzini Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 3/18/21 1:08 PM, Andrew Jones wrote: > On Thu, Mar 18, 2021 at 12:32:30PM +0100, Claudio Fontana wrote: >> And why do we have a separate arm_cpu_finalize_features()? > > Separate, because it's not just called from arm_cpu_realizefn(). In particular it is also called by the monitor.c in qmp_query_cpu_model_expansion(), which basically creates an object of the cpu subclass, and then calls arm_cpu_finalize_[features]() explicitly on the object. Is the qdev realize() method not called in this case? Should instead it be triggered, rather than initializing/realizing an incomplete object? > >> >> Nothing in the ARM cpu classes initializations ever seems to be "final" to me. > > Some CPU features cannot be simply switched on/off at the property > parse time. For example, there could be dependencies on multiple > properties, the mutual exclusion of properties, or other aspects > that can only be known later than property parse time. That stuff > goes in arm_cpu_finalize_features(). Seems like _part_ of that is in arm_cpu_finalize_[features]() (in practice, this ends up being AARCH64-only stuff, ie SVE, PAUTH and KVM). After calling that, the arm realizefn() also does further setting and unsetting of features, checking previous feature states. There is a whole lot following the arm_cpu_finalize_[features]() call, there are ~300 lines of features initializations happening _after_ the call to arm_cpu_finalize_[features](). > > Thanks, > drew >