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=-10.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 633FFC433ED for ; Tue, 13 Apr 2021 08:38:59 +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 C5105613AE for ; Tue, 13 Apr 2021 08:38:58 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C5105613AE 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]:43894 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lWEZW-0005X2-0g for qemu-devel@archiver.kernel.org; Tue, 13 Apr 2021 04:38:58 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:49568) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lWETH-0000bI-3w for qemu-devel@nongnu.org; Tue, 13 Apr 2021 04:32:31 -0400 Received: from mx2.suse.de ([195.135.220.15]:58958) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lWETB-00055d-KE for qemu-devel@nongnu.org; Tue, 13 Apr 2021 04:32:30 -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 0694AAFF1; Tue, 13 Apr 2021 08:32:24 +0000 (UTC) Subject: Re: [RFC v12 27/65] target/arm: split a15 cpu model and 32bit class functions to cpu32.c From: Claudio Fontana To: Richard Henderson , Peter Maydell , =?UTF-8?Q?Philippe_Mathieu-Daud=c3=a9?= , =?UTF-8?Q?Alex_Benn=c3=a9e?= References: <20210326193701.5981-1-cfontana@suse.de> <20210326193701.5981-28-cfontana@suse.de> <87e94d27-a1ec-cd6a-8079-0f975121d479@suse.de> Message-ID: <9fa0e6ae-2594-7a5f-6d5b-9d88495bb47a@suse.de> Date: Tue, 13 Apr 2021 10:32:23 +0200 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: <87e94d27-a1ec-cd6a-8079-0f975121d479@suse.de> 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 , Roman Bolshakov , qemu-devel@nongnu.org, Eduardo Habkost Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 4/8/21 12:23 PM, Claudio Fontana wrote: > On 3/28/21 6:18 PM, Richard Henderson wrote: >> On 3/26/21 1:36 PM, Claudio Fontana wrote: >>> provide helper functions there to initialize 32bit models, >>> and export the a15 cpu model. >>> >>> We still need to keep around a15 until we sort out the board configurations. >>> >>> cpu.c will continue to contain the common parts between >>> 32 and 64. >>> >>> Note that we need to build cpu32 also for TARGET_AARCH64, >>> because qemu-system-aarch64 is supposed to be able to run >>> non-aarch64 cpus too. >>> >>> Signed-off-by: Claudio Fontana >> >> Dump state has nothing to do with a15 or the 32-bit models. > > The relationship I see here is that 32-bit builds, > > only really need to use aarch32 version of the dump state, and they do not need to see the aarch64 version. > >> Moving that should be a separate change. >> >> The gdbstub changes are also a separate change, afaics. > > To hopefully clarify things a bit more here, the current hierarchy seems not right for ARM CPUs also in this respect. TYPE_ARM_CPU is the ancestor of all ARM CPUs, ok. TYPE_AARCH64_CPU is child of TYPE_ARM_CPU, ok. There is however no TYPE_AARCH32_CPU, or TYPE_ARM32_CPU. So what ends up being necessary here (both in the mainline code and in this patch, which just makes it more explicit), is to make the ancestor TYPE_ARM_CPU effectively a 32bit CPU class, with TYPE_AARCH64_CPU overriding class methods in order to morph it into a 64bit CPU class. What this patch does is to make it explicit, by creating a cpu32.c module that contains this non-explicit 32bit ARM CPU class methods, and the registration function to register 32bit ARM cpus. Thanks, Claudio > But the main concern is to split more, I understand: will do. > >> >> I don't understand the a15 comment above. Is it really relevant to moving the >> 32-bit cpu models? > > > The point there was that we keep around a15 for KVM for the moment, instead of relegating it to the set of "tcg-only" models, > so that virt board and qtest continue to function also in the KVM-only build. > > Mainly for this code here a question from my side: is the current code actually already "wrong"? > > I mean, we unconditionally set the aarch64-capable cpu classes to all use aarch64_gdb_arch_name and gdbstub64, > but what about an aarch64-capable cpu running in 32bit mode? > > Why don't we have, like tentatively done here for arm_cpu_dump_state, > > an arm_gdb_arch_name and an arm_cpu_gdb_read_register that check is_a64() and call aaarch32_cpu_gdb_read_register or aarch64_cpu_gdb_read_register accordingly? > > >> >> >> r~ >> >