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=-3.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS 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 4CD6BC433B4 for ; Tue, 6 Apr 2021 06:13:35 +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 CEAA661369 for ; Tue, 6 Apr 2021 06:13:33 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CEAA661369 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=gibson.dropbear.id.au Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:60850 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lTexw-0000F4-Te for qemu-devel@archiver.kernel.org; Tue, 06 Apr 2021 02:13:32 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:34718) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lTewP-000899-HY; Tue, 06 Apr 2021 02:11:57 -0400 Received: from ozlabs.org ([2401:3900:2:1::2]:42919) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lTewM-0005jG-Qk; Tue, 06 Apr 2021 02:11:57 -0400 Received: by ozlabs.org (Postfix, from userid 1007) id 4FDxxT2HLtz9sW1; Tue, 6 Apr 2021 16:11:41 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gibson.dropbear.id.au; s=201602; t=1617689501; bh=U9q5mvqYI3eiuzsklh79CWhe+YWT7ayJrKnhr3pov58=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=PRwRweTqY2BZJuQ0yhvrMSzC3kLQ8AkS5YL/uhx3CpSMj7K/+vdD+p+h7uM22X1H9 74uv/RaD0IK/ca3fX10dYnBz6hf+vE1jSaZS6zxSrvGMRhzSgq+RsNVKD1YMabNQVG FHUVqSVrISq1zL4rNzZQ1IQx+3ilcCFrW8liQKiQ= Date: Tue, 6 Apr 2021 16:11:30 +1000 From: David Gibson To: Bruno Piazera Larsen Subject: Re: Discussion: Patch series that adds disable-tcg option for ppc targets Message-ID: References: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="VLRC6jUEnB73qPvG" Content-Disposition: inline In-Reply-To: Received-SPF: pass client-ip=2401:3900:2:1::2; envelope-from=dgibson@ozlabs.org; helo=ozlabs.org X-Spam_score_int: -17 X-Spam_score: -1.8 X-Spam_bar: - X-Spam_report: (-1.8 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, HEADER_FROM_DIFFERENT_DOMAINS=0.25, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=no 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@nongnu.org" , Lucas Mateus Martins Araujo e Castro , Fernando Eckhardt Valle , "qemu-ppc@nongnu.org" , Andre Fernando da Silva , Matheus Kowalczuk Ferst , Luis Fernando Fujita Pires Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" --VLRC6jUEnB73qPvG Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Apr 05, 2021 at 01:32:18PM +0000, Bruno Piazera Larsen wrote: > Hi all, >=20 > The team I'm working on started to work on adding support for > building the ppc target with the disable-tcg option. However, we're > not quite sure on where to start with such a big patch. >=20 > * Should we focus first on changing the .c files, so that it > will build when we finally patch the meson.build everything > build correctly? Or should we start by changing the meson > file, so that everyone agrees that the excluded files can > indeed be excluded? It's usually best to focus on logical changes, rather than file-by-file. That said, I'd probably suggest changing the .c files first, then changing the meson file. > * Should we first finish the whole series to then mail it, or > should we send one file at a time, as soon as we have them > ready? I'd lean towards building a whole series, since I think the individual file changes won't make a lot of sense on their own. That said, it's ok and encouraged to post a relatively early draft of the series as an RFC, so that the overall idea can be reviewed, even if it has obvious omissions (just mention them in the cover letter). > So far we're thinking we'll need to: > * change 6 files (arch_dump.c, machine.c, mmu-hash32.c, > mmu-hash64.c, mmu-radix64.c and meson.build); I'd expect mmu-*.c to be excluded. Those are softmmu implementations which shouldn't be used with KVM. It's possible there are a few helpers that will need to be extracted, though. You'll probably also need changes in hw/ppc/spapr_hcall.c and maybe some other parts of the spapr code: there are a number of hypercalls that we implement in qemu for TCG, but which are (and must be) implemented in KVM when KVM is in use. So, I expect you'll need to suppress compilation of h_enter, h_remove, h_protect, h_read and h_bulk_remove at least in the !TCG case. > * exclude 8 files from the build (dfp_helper.c, excp_helper.c, > fpu_helper.c, int_helper.c, mem_helper.c, misc_helper.c, * > translate.c, timebase_helper.c); That looks about right. > * create a new one that holds stubs. Sounds reasonable. > Does this sound about right? This is mostly guesswork based on how > x86, s390x and ARM are doing it. Sounds fine so far. --=20 David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson --VLRC6jUEnB73qPvG Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEdfRlhq5hpmzETofcbDjKyiDZs5IFAmBr+5AACgkQbDjKyiDZ s5L77BAAlafce95p2Q1YiPwLsEyigqRjZFOCZTplOX1zaVIhfY1/gBB/q7X1qTNG xDXyabN9Z+EhFfj8P9QEHeKTMQbhrg9vQKQpkIIfEjpFUwr6LVg+Mcd3VmmOgvd7 Hk2DHPgYN/NJyGVWAiYoKJHXtJo79Am9xymRiJNHM0K/KwFh54KJEJ84qOkOTtpF 6rRufEyNvkpxxKAGZ4HhhLeuPwaxqj/jvXv11ViO/y5WFCWkNkuthdfH9D5XuGuA BWJXKw36MJDUOj3bqBfzQTlIaNV+hb0yyd5zyLTNCk0UjTlBHrE5/DJIvQw30ikq eYC0TsDQju3kCYQdBogCF0fpoMiquyy+VmTgBDmITgcTvSmsg2oP/R60L9wABaia swGkS8q0/Gt665OIcyH9ph6yZmpsXpBT85hwpuamkKWaUuwxbBltdPx6i9UD/AeZ EDk8NAyx4uWEu7PtpzodjTP6rAfs281UP7FH5wKdLNlVzive+1EItraXKPm0Zvvn sBsd23woR0j+rLI8SpNibg2cgEUcbe2bfxsmLLYtjAp9EJFRDCsp686xthA3470Y Yu7T8yafXAZ+c3ONnoUn5RZ/owFdkLbuNesLBovrkafvdJlx9R3lZA56jh6ag/pi cw2F6hVPAETdM0erFN5ZWtWkj8zHuMTq5p9akmDEBHpKQ45bArU= =xPhJ -----END PGP SIGNATURE----- --VLRC6jUEnB73qPvG--