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=-5.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,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 E07AFC433B4 for ; Thu, 13 May 2021 15:21:13 +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 6894F61166 for ; Thu, 13 May 2021 15:21:13 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6894F61166 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:59444 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lhD9E-0007B2-JN for qemu-devel@archiver.kernel.org; Thu, 13 May 2021 11:21:12 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:50274) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lhD8J-0006CI-V5 for qemu-devel@nongnu.org; Thu, 13 May 2021 11:20:16 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:53053) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lhD8I-0003pF-6g for qemu-devel@nongnu.org; Thu, 13 May 2021 11:20:15 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1620919212; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=UUOBG96FeKEAlythuay7krrBFUO5qGFP5H/0apHhH4o=; b=a+xQmMkICrJX3nKQorWUR8ZwnyShkL1Ct8l51H/fsiKBg+YtRf/v9ho3lb6DNKhsRojlCj pWip+pP604QPpu8iyRD0+GPTiixcmxr+ty/jnDTqFy6lugox1NWUaVFe82jxl3MyhFCzmM 3/+0CPFF9fL2U5KhWxZMPCOCihQs+fc= Received: from mail-ed1-f69.google.com (mail-ed1-f69.google.com [209.85.208.69]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-76-dswlY48gNDGTOquCtpEmdQ-1; Thu, 13 May 2021 11:20:11 -0400 X-MC-Unique: dswlY48gNDGTOquCtpEmdQ-1 Received: by mail-ed1-f69.google.com with SMTP id n6-20020a0564020606b029038cdc241890so1312204edv.20 for ; Thu, 13 May 2021 08:20:10 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=UUOBG96FeKEAlythuay7krrBFUO5qGFP5H/0apHhH4o=; b=QfPl0gS86j20aeJzqj8y+Wx48IR69qjylejhbMD81DjJPLA6C3qipmCFyLpapZly/e NnZR2NO4B9fPCX/nOb870ytXZwFkqLqgu2fCLG+V1ZSKsGD3SeldRGNGla1gJSqmFEqQ BLUTbEfEr505OKZE/KEI5oHG0yn2MKme7xCHhIsQRVHPWvMeS6GW36wp3Gvb5+wrWSn6 Kqp4GYin4FdqKMQgSlu/sQyV1pL5EsL0vMo5xzPpTNbXbbWvyKSI4vxQklP8rGaeOBku ENIYp7IDmPe+nszyuMfhGL3KUWlR2hbOcxIYdWqP3TgGvR7SQy4l2YK05RG7pYyDcmi+ DBMA== X-Gm-Message-State: AOAM532htFUvvxwHwG/oypKWv6D7eg4Y6y5A0/sSPO6dVwwyDukH8z5j i5xU3AqLVnhBApitqpQOZlmhcm8+hy25Ko5773MpbA5Uhj65BGEmcRVdsuXzftgwFvu3FrXlRLe n6AyW5tGbpN/DHgE= X-Received: by 2002:a17:907:7b9f:: with SMTP id ne31mr44208006ejc.139.1620919209974; Thu, 13 May 2021 08:20:09 -0700 (PDT) X-Google-Smtp-Source: ABdhPJymOdujMxaXXpY3LuHPfnbn0hZHScRz6IRn/N1AeOhzkaz90+0pM+e7mmcvl4/n2el0DS3acw== X-Received: by 2002:a17:907:7b9f:: with SMTP id ne31mr44207985ejc.139.1620919209744; Thu, 13 May 2021 08:20:09 -0700 (PDT) Received: from ?IPv6:2001:b07:6468:f312:c8dd:75d4:99ab:290a? ([2001:b07:6468:f312:c8dd:75d4:99ab:290a]) by smtp.gmail.com with ESMTPSA id aj8sm1928704ejc.64.2021.05.13.08.20.07 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 13 May 2021 08:20:09 -0700 (PDT) Subject: Re: [RFC PATCH 1/5] hw/mem/nvdimm: Use Kconfig 'imply' instead of 'depends on' To: David Gibson , Thomas Huth References: <20210511155354.3069141-1-philmd@redhat.com> <20210511155354.3069141-2-philmd@redhat.com> <21e0a306-ccfb-a627-1496-14f831fe80a7@redhat.com> From: Paolo Bonzini Message-ID: <161fa4ca-5407-790c-8e2f-e0665c89fd6f@redhat.com> Date: Thu, 13 May 2021 17:20:06 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=pbonzini@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=windows-1252; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=170.10.133.124; envelope-from=pbonzini@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -34 X-Spam_score: -3.5 X-Spam_bar: --- X-Spam_report: (-3.5 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.699, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, NICE_REPLY_A=-0.001, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=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 , "Michael S. Tsirkin" , Alexey Kardashevskiy , Richard Henderson , qemu-devel@nongnu.org, Greg Kurz , "open list:ARM TCG CPUs" , qemu-ppc@nongnu.org, John Paul Adrian Glaubitz , Igor Mammedov , =?UTF-8?Q?Philippe_Mathieu-Daud=c3=a9?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 12/05/21 09:02, David Gibson wrote: >> But with "imply" you could end up with a PSERIES that does not have NVDIMM >> when also using --without-default-devices, couldn't you? Why don't you use >> "select" instead of "imply" ? > Oh.. clearly I misunderstand the semantics of "imply". If we don't > need NVDIMM for PSERIES, why does there need to be any Kconfig > connection between them at all? Because you still want it in the binary by default (i.e. unless --without-default-devices). Basically, config PSERIES imply NVDIMM is the same as config NVDIMM default y if PSERIES Both of them are a way to say "PSERIES can work with NVDIMM so you want to include it unless you want some fine tuning". In Linux "imply" is very rarely used, while in QEMU it's quite common because it keeps the many per-board defaults close together. Paolo