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=-8.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS 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 A629FC47082 for ; Wed, 26 May 2021 08:18:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 861E96143E for ; Wed, 26 May 2021 08:18:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232277AbhEZIUM (ORCPT ); Wed, 26 May 2021 04:20:12 -0400 Received: from mail-vs1-f53.google.com ([209.85.217.53]:44981 "EHLO mail-vs1-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231871AbhEZIUL (ORCPT ); Wed, 26 May 2021 04:20:11 -0400 Received: by mail-vs1-f53.google.com with SMTP id i29so269451vsr.11; Wed, 26 May 2021 01:18:39 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=cwJrjJPn4XdJtdaNHc/uwJ41Erytueup9SA7gWbLwLc=; b=TknXp62Tjdb47E3sod/c1NOiYYHO++PTLTTWUJX+idsZnBM6TlK+rPjtrMshFThGOM abPpAvRNdbOyIaX2o+bUmETZIhzLzePKfK9DHMgihVnqHE/Bb5hJUCmkde6ssKEX1pBA Cj8ex/3+TI9m5p7nUHTN6calnOWMoJJfMTdIIyLjwKKsohApGRgi8KFk3t75/A6wzLZ3 tIa8KT5xjnC8XZrAjX9B1EHC6Gy5qJMvpz/hD5ak9zLqiRG6QC/d2KSrA04/ipMh4VPa Qbcbw2bmk+1cgUAQKE+rzWa0tFGoeMNF5qJK8lQwwgUetVMvZYa/3/EnR/S1+xFaht26 tZRw== X-Gm-Message-State: AOAM5327cB3tMOp6D02b/MAH/9MGXjv6b2095JOT+5UBgxfpuesmEYZX OjidG/3HDJqhAh+HBX/96JqEtI1gNaHpR4HjQvI= X-Google-Smtp-Source: ABdhPJyBP43fy0z/xLr24CBnaFxqMibw4+PtPqA/CPHen7oIzefuWsMGVqm5mGd8u6JPJ0dQP9MmoI2MjgM94cpGp3U= X-Received: by 2002:a67:3c2:: with SMTP id 185mr30138437vsd.42.1622017119229; Wed, 26 May 2021 01:18:39 -0700 (PDT) MIME-Version: 1.0 References: <20210330145430.996981-1-maz@kernel.org> <20210330145430.996981-8-maz@kernel.org> <6c522f8116f54fa6f23a2d217d966c5a@kernel.org> <8735u9x6sb.wl-maz@kernel.org> In-Reply-To: <8735u9x6sb.wl-maz@kernel.org> From: Geert Uytterhoeven Date: Wed, 26 May 2021 10:18:27 +0200 Message-ID: Subject: Re: [PATCH v19 7/7] ptp: arm/arm64: Enable ptp_kvm for arm/arm64 To: Marc Zyngier Cc: jianyong.wu@arm.com, netdev , Yangbo Lu , John Stultz , Thomas Gleixner , Paolo Bonzini , seanjc@google.com, Richard Cochran , Mark Rutland , Will Deacon , Suzuki K Poulose , Andre Przywara , Steven Price , Lorenzo Pieralisi , Sudeep Holla , Linux Kernel Mailing List , Linux ARM , kvmarm@lists.cs.columbia.edu, KVM list , Steve Capper , justin.he@arm.com, Android Kernel Team Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Hi Marc, On Wed, May 26, 2021 at 10:01 AM Marc Zyngier wrote: > On Wed, 26 May 2021 08:52:42 +0100, > Geert Uytterhoeven wrote: > > On Tue, May 11, 2021 at 11:13 AM Marc Zyngier wrote: > > > On 2021-05-11 10:07, Geert Uytterhoeven wrote: > > > > On Tue, Mar 30, 2021 at 4:56 PM Marc Zyngier wrote: > > > >> From: Jianyong Wu > > > > > > > >> --- a/drivers/ptp/Kconfig > > > >> +++ b/drivers/ptp/Kconfig > > > >> @@ -108,7 +108,7 @@ config PTP_1588_CLOCK_PCH > > > >> config PTP_1588_CLOCK_KVM > > > >> tristate "KVM virtual PTP clock" > > > >> depends on PTP_1588_CLOCK > > > >> - depends on KVM_GUEST && X86 > > > >> + depends on (KVM_GUEST && X86) || (HAVE_ARM_SMCCC_DISCOVERY && > > > >> ARM_ARCH_TIMER) > > > > > > > > Why does this not depend on KVM_GUEST on ARM? > > > > I.e. shouldn't the dependency be: > > > > > > > > KVM_GUEST && (X86 || (HAVE_ARM_SMCCC_DISCOVERY && ARM_ARCH_TIMER)) > > > > > > > > ? > > > > > > arm/arm64 do not select KVM_GUEST. Any kernel can be used for a guest, > > > and KVM/arm64 doesn't know about this configuration symbol. > > > > OK. > > > > Does PTP_1588_CLOCK_KVM need to default to yes? > > Perhaps only on X86, to maintain the status quo? > > I think I don't really understand the problem you are trying to > solve. Is it that 'make oldconfig' now asks you about this new driver? > Why is that an issue? My first "problem" was that it asked about this new driver on arm/arm64, while I assumed there were some missing dependencies (configuring a kernel should not ask useless questions). That turned out to be a wrong assumption, so there is no such problem here. The second problem is "default y": code that is not critical should not be enabled by default. Hence my last question. Thanks! Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds