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From:   Daniel Axtens <dja@axtens.net>
To:     Lukas Bulwahn <lukas.bulwahn@gmail.com>,
        Paul Mackerras <paulus@ozlabs.org>,
        Michael Ellerman <mpe@ellerman.id.au>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Michael Neuling <mikey@neuling.org>,
        Anshuman Khandual <anshuman.khandual@arm.com>,
        kvm-ppc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
Cc:     Lukas Bulwahn <lukas.bulwahn@gmail.com>,
        kernel-janitors@vger.kernel.org, stable@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 1/2] powerpc: kvm: remove obsolete and unneeded select
In-Reply-To: <20210819113954.17515-2-lukas.bulwahn@gmail.com>
References: <20210819113954.17515-1-lukas.bulwahn@gmail.com>
 <20210819113954.17515-2-lukas.bulwahn@gmail.com>
Date:   Fri, 20 Aug 2021 08:39:45 +1000
Message-ID: <87sfz59hzi.fsf@dja-thinkpad.axtens.net>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

Hi Lukas,

> diff --git a/arch/powerpc/kvm/Kconfig b/arch/powerpc/kvm/Kconfig
> index e45644657d49..ff581d70f20c 100644
> --- a/arch/powerpc/kvm/Kconfig
> +++ b/arch/powerpc/kvm/Kconfig
> @@ -38,7 +38,6 @@ config KVM_BOOK3S_32_HANDLER
>  config KVM_BOOK3S_64_HANDLER
>  	bool
>  	select KVM_BOOK3S_HANDLER
> -	select PPC_DAWR_FORCE_ENABLE

I looked at some of the history here. It looks like this select was left
over from an earlier version of the patch series that added PPC_DAWR: v2
of the series has a new symbol PPC_DAWR_FORCE_ENABLE but by version 4
that new symbol had disappeared but the select had not.

v2: https://lore.kernel.org/linuxppc-dev/20190513071703.25243-1-mikey@neuling.org/
v5: https://lore.kernel.org/linuxppc-dev/20190604030037.9424-2-mikey@neuling.org/

The rest of the patch reasoning makes sense to me: DAWR support will be
selected anyway by virtue of PPC64->PPC_DAWR so there's no need to try
to select it again anyway.

Reviewed-by: Daniel Axtens <dja@axtens.net>

Kind regards,
Daniel

>  
>  config KVM_BOOK3S_PR_POSSIBLE
>  	bool
> -- 
> 2.26.2