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=-5.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 6AB86C3815B for ; Fri, 17 Apr 2020 09:33:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3E08A20776 for ; Fri, 17 Apr 2020 09:33:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="TEDWZSBS" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730346AbgDQJdQ (ORCPT ); Fri, 17 Apr 2020 05:33:16 -0400 Received: from us-smtp-2.mimecast.com ([207.211.31.81]:31820 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1730333AbgDQJdO (ORCPT ); Fri, 17 Apr 2020 05:33:14 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1587115992; 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=JhGeUvxGcTXLdmHA9NT0UPQF+FHUIR0Zeja74ZUVplA=; b=TEDWZSBS/UxK9PJgwSRIxgwJ4LqRjOtYQaz9knlty0tRviOy74zJH/qBM2Ar37nJSfJ8Xa rxJ2vBqU0PDmNSTQn28wZsCQNUjjgH+6XI0ziwMhANOdB/skySQemJOhR77eGcA85OqxTy 1rLiCvqHJ6imUnMmKU74FRfE0plg62Y= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-369-OVKHQIXwNXKHVGLh1l_TJQ-1; Fri, 17 Apr 2020 05:33:08 -0400 X-MC-Unique: OVKHQIXwNXKHVGLh1l_TJQ-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id B3C53107ACCA; Fri, 17 Apr 2020 09:33:06 +0000 (UTC) Received: from [10.72.13.157] (ovpn-13-157.pek2.redhat.com [10.72.13.157]) by smtp.corp.redhat.com (Postfix) with ESMTP id 86A0A5C1D6; Fri, 17 Apr 2020 09:32:58 +0000 (UTC) Subject: Re: [PATCH V2] vhost: do not enable VHOST_MENU by default To: Geert Uytterhoeven , "Michael S. Tsirkin" Cc: "open list:BROADCOM NVRAM DRIVER" , Linux Kernel Mailing List , linuxppc-dev , linux-s390 , KVM list , virtualization@lists.linux-foundation.org, netdev , Thomas Bogendoerfer , Benjamin Herrenschmidt , Paul Mackerras , Heiko Carstens , Vasily Gorbik , Christian Borntraeger , Michael Ellerman References: <20200415024356.23751-1-jasowang@redhat.com> <20200416185426-mutt-send-email-mst@kernel.org> <20200417022929-mutt-send-email-mst@kernel.org> <4274625d-6feb-81b6-5b0a-695229e7c33d@redhat.com> <20200417042912-mutt-send-email-mst@kernel.org> <20200417044230-mutt-send-email-mst@kernel.org> <73843240-3040-655d-baa9-683341ed4786@redhat.com> <20200417045454-mutt-send-email-mst@kernel.org> From: Jason Wang Message-ID: <2f5681bb-a8e6-fe73-57f5-24de7a5a72e8@redhat.com> Date: Fri, 17 Apr 2020 17:32:57 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Content-Transfer-Encoding: quoted-printable Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2020/4/17 =E4=B8=8B=E5=8D=885:25, Geert Uytterhoeven wrote: > Hi Michael, > > On Fri, Apr 17, 2020 at 10:57 AM Michael S. Tsirkin wr= ote: >> On Fri, Apr 17, 2020 at 04:51:19PM +0800, Jason Wang wrote: >>> On 2020/4/17 =E4=B8=8B=E5=8D=884:46, Michael S. Tsirkin wrote: >>>> On Fri, Apr 17, 2020 at 04:39:49PM +0800, Jason Wang wrote: >>>>> On 2020/4/17 =E4=B8=8B=E5=8D=884:29, Michael S. Tsirkin wrote: >>>>>> On Fri, Apr 17, 2020 at 03:36:52PM +0800, Jason Wang wrote: >>>>>>> On 2020/4/17 =E4=B8=8B=E5=8D=882:33, Michael S. Tsirkin wrote: >>>>>>>> On Fri, Apr 17, 2020 at 11:12:14AM +0800, Jason Wang wrote: >>>>>>>>> On 2020/4/17 =E4=B8=8A=E5=8D=886:55, Michael S. Tsirkin wrote: >>>>>>>>>> On Wed, Apr 15, 2020 at 10:43:56AM +0800, Jason Wang wrote: >>>>>>>>>>> We try to keep the defconfig untouched after decoupling CONFI= G_VHOST >>>>>>>>>>> out of CONFIG_VIRTUALIZATION in commit 20c384f1ea1a >>>>>>>>>>> ("vhost: refine vhost and vringh kconfig") by enabling VHOST_= MENU by >>>>>>>>>>> default. Then the defconfigs can keep enabling CONFIG_VHOST_N= ET >>>>>>>>>>> without the caring of CONFIG_VHOST. >>>>>>>>>>> >>>>>>>>>>> But this will leave a "CONFIG_VHOST_MENU=3Dy" in all defconfi= gs and even >>>>>>>>>>> for the ones that doesn't want vhost. So it actually shifts t= he >>>>>>>>>>> burdens to the maintainers of all other to add "CONFIG_VHOST_= MENU is >>>>>>>>>>> not set". So this patch tries to enable CONFIG_VHOST explicit= ly in >>>>>>>>>>> defconfigs that enables CONFIG_VHOST_NET and CONFIG_VHOST_VSO= CK. >>>>>>>>>>> >>>>>>>>>>> Acked-by: Christian Borntraeger (s= 390) >>>>>>>>>>> Acked-by: Michael Ellerman (powerpc) >>>>>>>>>>> Cc: Thomas Bogendoerfer >>>>>>>>>>> Cc: Benjamin Herrenschmidt >>>>>>>>>>> Cc: Paul Mackerras >>>>>>>>>>> Cc: Michael Ellerman >>>>>>>>>>> Cc: Heiko Carstens >>>>>>>>>>> Cc: Vasily Gorbik >>>>>>>>>>> Cc: Christian Borntraeger >>>>>>>>>>> Reported-by: Geert Uytterhoeven >>>>>>>>>>> Signed-off-by: Jason Wang >>>>>>>>>> I rebased this on top of OABI fix since that >>>>>>>>>> seems more orgent to fix. >>>>>>>>>> Pushed to my vhost branch pls take a look and >>>>>>>>>> if possible test. >>>>>>>>>> Thanks! >>>>>>>>> I test this patch by generating the defconfigs that wants vhost= _net or >>>>>>>>> vhost_vsock. All looks fine. >>>>>>>>> >>>>>>>>> But having CONFIG_VHOST_DPN=3Dy may end up with the similar sit= uation that >>>>>>>>> this patch want to address. >>>>>>>>> Maybe we can let CONFIG_VHOST depends on !ARM || AEABI then add= another >>>>>>>>> menuconfig for VHOST_RING and do something similar? >>>>>>>>> >>>>>>>>> Thanks >>>>>>>> Sorry I don't understand. After this patch CONFIG_VHOST_DPN is j= ust >>>>>>>> an internal variable for the OABI fix. I kept it separate >>>>>>>> so it's easy to revert for 5.8. Yes we could squash it into >>>>>>>> VHOST directly but I don't see how that changes logic at all. >>>>>>> Sorry for being unclear. >>>>>>> >>>>>>> I meant since it was enabled by default, "CONFIG_VHOST_DPN=3Dy" w= ill be left >>>>>>> in the defconfigs. >>>>>> But who cares? >>>>> FYI, please seehttps://www.spinics.net/lists/kvm/msg212685.html >>>> The complaint was not about the symbol IIUC. It was that we caused >>>> everyone to build vhost unless they manually disabled it. >>> There could be some misunderstanding here. I thought it's somehow sim= ilar: a >>> CONFIG_VHOST_MENU=3Dy will be left in the defconfigs even if CONFIG_V= HOST is >>> not set. >>> >>> Thanks >> Hmm. So looking at Documentation/kbuild/kconfig-language.rst : >> >> Things that merit "default y/m" include: >> >> a) A new Kconfig option for something that used to always be = built >> should be "default y". >> >> b) A new gatekeeping Kconfig option that hides/shows other Kc= onfig >> options (but does not generate any code of its own), shoul= d be >> "default y" so people will see those other options. >> >> c) Sub-driver behavior or similar options for a driver that i= s >> "default n". This allows you to provide sane defaults. >> >> >> So it looks like VHOST_MENU is actually matching rule b). >> So what's the problem we are trying to solve with this patch, exactly? >> >> Geert could you clarify pls? > I can confirm VHOST_MENU is matching rule b), so it is safe to always > enable it. > > Gr{oetje,eeting}s, > > Geert Right, so I think we can drop this patch. Thanks