Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Wed, 26 May 2021 09:01:40 +0100
Message-ID: <8735u9x6sb.wl-maz@kernel.org>
From:   Marc Zyngier <maz@kernel.org>
To:     Geert Uytterhoeven <geert@linux-m68k.org>
Cc:     jianyong.wu@arm.com, netdev <netdev@vger.kernel.org>,
        Yangbo Lu <yangbo.lu@nxp.com>,
        John Stultz <john.stultz@linaro.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Paolo Bonzini <pbonzini@redhat.com>, seanjc@google.com,
        Richard Cochran <richardcochran@gmail.com>,
        Mark Rutland <Mark.Rutland@arm.com>,
        Will Deacon <will@kernel.org>,
        Suzuki K Poulose <suzuki.poulose@arm.com>,
        Andre Przywara <Andre.Przywara@arm.com>,
        Steven Price <steven.price@arm.com>,
        Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
        Sudeep Holla <sudeep.holla@arm.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>,
        kvmarm@lists.cs.columbia.edu, KVM list <kvm@vger.kernel.org>,
        Steve Capper <Steve.Capper@arm.com>, justin.he@arm.com,
        Android Kernel Team <kernel-team@android.com>
Subject: Re: [PATCH v19 7/7] ptp: arm/arm64: Enable ptp_kvm for arm/arm64
In-Reply-To: <CAMuHMdWzBqLVOVn_z8S2H-x-kL+DfOsM5mDb_D8OKsyRJtKpdA@mail.gmail.com>
References: <20210330145430.996981-1-maz@kernel.org>
        <20210330145430.996981-8-maz@kernel.org>
        <CAMuHMdWd5261ti-zKsroFLvWs0abaWa7G4DKefgPwFb3rEjnNw@mail.gmail.com>
        <6c522f8116f54fa6f23a2d217d966c5a@kernel.org>
        <CAMuHMdWzBqLVOVn_z8S2H-x-kL+DfOsM5mDb_D8OKsyRJtKpdA@mail.gmail.com>
User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue)
 FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/27.1
 (x86_64-pc-linux-gnu) MULE/6.0 (HANACHIRUSATO)
MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue")
Content-Type: text/plain; charset=US-ASCII
Precedence: bulk

Hi Geert,

On Wed, 26 May 2021 08:52:42 +0100,
Geert Uytterhoeven <geert@linux-m68k.org> wrote:
> 
> Hi Marc,
> 
> On Tue, May 11, 2021 at 11:13 AM Marc Zyngier <maz@kernel.org> wrote:
> > On 2021-05-11 10:07, Geert Uytterhoeven wrote:
> > > On Tue, Mar 30, 2021 at 4:56 PM Marc Zyngier <maz@kernel.org> wrote:
> > >> From: Jianyong Wu <jianyong.wu@arm.com>
> > >
> > >> --- 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?

Thanks,

	M.

-- 
Without deviation from the norm, progress is not possible.