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 77650C433E0 for ; Tue, 2 Mar 2021 11:59:33 +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 C7E0764FC6 for ; Tue, 2 Mar 2021 11:59:32 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C7E0764FC6 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]:58794 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lH3gZ-0007hQ-NT for qemu-devel@archiver.kernel.org; Tue, 02 Mar 2021 06:59:31 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:50460) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lH3g0-0007Cn-NP for qemu-devel@nongnu.org; Tue, 02 Mar 2021 06:58:56 -0500 Received: from mx2.suse.de ([195.135.220.15]:55562) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lH3fz-0005WW-1k for qemu-devel@nongnu.org; Tue, 02 Mar 2021 06:58:56 -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 624A1B120; Tue, 2 Mar 2021 11:58:53 +0000 (UTC) Subject: Re: [RFC v2 19/24] target/arm: move aarch64_sync_32_to_64 (and vv) to cpu code To: Richard Henderson References: <20210301164936.19446-1-cfontana@suse.de> <20210301164936.19446-20-cfontana@suse.de> <3c8622f8-cf47-2819-c351-8051c2725155@linaro.org> From: Claudio Fontana Message-ID: <564ba572-b323-eca4-4cf6-c2c466f7f795@suse.de> Date: Tue, 2 Mar 2021 12:58:52 +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: <3c8622f8-cf47-2819-c351-8051c2725155@linaro.org> 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: qemu-devel Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 3/2/21 7:23 AM, Richard Henderson wrote: > On 3/1/21 8:49 AM, Claudio Fontana wrote: >> and arm_phys_excp_target_el since it is tied up inside the >> same #ifdef block. >> >> aarch64_sync_32_to_64 and aarch64_sync_64_to_32 are >> mixed in with the tcg helpers, but they shouldn't, as they >> are needed for kvm too, in the sysemu case. > > Really? Now that *is* surprising. Again, please document. Because I surely > cannot believe this to be used by kvm. > > > r~ > Ok, will add comment here as well, they are needed by kvm64.c There is lots that surprised me too on how kvm is bolted on top of tcg code currently; partly related to this, if it can help understand this, in kvm.c notice the kvm_arm_init_cpreg_list(): it basically undoes all TCG initializations in the cpreg_indexes, cpreg_values etc, and rebuilds the cpreg list based on the list read from the kernel. Then, in kvm64.c: kvm_arch_get_registers() { ... if (!is_a64(env)) { aarch64_sync_64_to_32(env); } ... write_kvmstate_to_list(cpu); ... write_list_to_cpustate(cpu); ... } kvm_arch_put_registers() { ... if (!is_a64(env)) { aarch64_sync_32_to_64(env); } ... write_cpustate_to_list(cpu, true); ... write_list_to_kvmstate(cpu, level) ... } Thanks, Claudio