Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <a157c5e7-d90c-5b99-42bb-ae02b6677732@collabora.com>
Date:   Fri, 14 Apr 2023 12:48:19 +0200
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.9.1
Subject: Re: [PATCH v1 3/6] soc: mediatek: virt: geniezone: Introduce
 GenieZone hypervisor support
Content-Language: en-US
To:     =?UTF-8?B?WWktRGUgV3UgKOWQs+S4gOW+tyk=?= <Yi-De.Wu@mediatek.com>,
        "corbet@lwn.net" <corbet@lwn.net>,
        "robh+dt@kernel.org" <robh+dt@kernel.org>,
        "krzysztof.kozlowski@linaro.org" <krzysztof.kozlowski@linaro.org>,
        "catalin.marinas@arm.com" <catalin.marinas@arm.com>,
        "krzysztof.kozlowski+dt@linaro.org" 
        <krzysztof.kozlowski+dt@linaro.org>,
        =?UTF-8?B?WWluZ3NoaXVhbiBQYW4gKOa9mOepjui7kik=?= 
        <Yingshiuan.Pan@mediatek.com>,
        "matthias.bgg@gmail.com" <matthias.bgg@gmail.com>,
        "will@kernel.org" <will@kernel.org>
Cc:     "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "linux-mediatek@lists.infradead.org" 
        <linux-mediatek@lists.infradead.org>,
        =?UTF-8?B?TVkgQ2h1YW5nICjojormmI7ouo0p?= <MY.Chuang@mediatek.com>,
        "devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
        =?UTF-8?B?UGVpTHVuIFN1ZWkgKOmai+WfueWAqyk=?= 
        <PeiLun.Suei@mediatek.com>,
        =?UTF-8?B?TGlqdS1jbHIgQ2hlbiAo6Zmz6bqX5aaCKQ==?= 
        <Liju-clr.Chen@mediatek.com>,
        =?UTF-8?B?SmFkZXMgU2hpaCAo5pa95ZCR546oKQ==?= 
        <jades.shih@mediatek.com>,
        "linux-arm-kernel@lists.infradead.org" 
        <linux-arm-kernel@lists.infradead.org>,
        =?UTF-8?B?U2hhd24gSHNpYW8gKOiVreW/l+elpSk=?= 
        <shawn.hsiao@mediatek.com>,
        =?UTF-8?B?TWlsZXMgQ2hlbiAo6Zmz5rCR5qi6KQ==?= 
        <Miles.Chen@mediatek.com>,
        "linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org>,
        =?UTF-8?B?SXZhbiBUc2VuZyAo5pu+5b+X6LuSKQ==?= 
        <ivan.tseng@mediatek.com>,
        =?UTF-8?B?WmUteXUgV2FuZyAo546L5r6k5a6HKQ==?= 
        <Ze-yu.Wang@mediatek.com>
References: <20230413090735.4182-1-yi-de.wu@mediatek.com>
 <20230413090735.4182-4-yi-de.wu@mediatek.com>
 <1aa701cc-92ca-71be-0663-df4bfae66c2f@linaro.org>
 <5c1d69c8-d973-fa7b-1f14-c72729ff5594@gmail.com>
 <533a1a9b653cf63f1e5df7f95d1b23902809561d.camel@mediatek.com>
From:   AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@collabora.com>
In-Reply-To: <533a1a9b653cf63f1e5df7f95d1b23902809561d.camel@mediatek.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
Precedence: bulk

Il 14/04/23 10:43, Yi-De Wu (吳一德) ha scritto:
> On Thu, 2023-04-13 at 19:08 +0200, Matthias Brugger wrote:
>> External email : Please do not click links or open attachments until
>> you have verified the sender or the content.
>>
>>
>> On 13/04/2023 14:55, Krzysztof Kozlowski wrote:
>>> On 13/04/2023 11:07, Yi-De Wu wrote:
>>>> From: "Yingshiuan Pan" <yingshiuan.pan@mediatek.com>
>>>>
>>>> GenieZone is MediaTek proprietary hypervisor solution, and it is
>>>> running
>>>> in EL2 stand alone as a type-I hypervisor. This patch exports a
>>>> set of
>>>> ioctl interfaces for userspace VMM (e.g., crosvm) to operate
>>>> guest VMs
>>>> lifecycle (creation, running, and destroy) on GenieZone.
>>>>
>>>> Signed-off-by: Yingshiuan Pan <yingshiuan.pan@mediatek.com>
>>>> Signed-off-by: Yi-De Wu <yi-de.wu@mediatek.com>
>>>> ---
>>>>    arch/arm64/include/uapi/asm/gzvm_arch.h       |  79 ++++
>>>>    drivers/soc/mediatek/Kconfig                  |   2 +
>>>>    drivers/soc/mediatek/Makefile                 |   1 +
>>>>    drivers/soc/mediatek/virt/geniezone/Kconfig   |  17 +
>>>
>>> Hypervisor drivers do not go to soc. Stop shoving there everything
>>> from
>>> your downstream. Find appropriate directory, e.g. maybe
>>> drivers/virt.
>>
>> Acked, what is the reason you want to add this to drivers/soc instead
>> of
>> drivers/virt?
>>
>> Regards,
>> Matthias
>>
> Noted. We would take your advice and move it from
> drivers/soc/mediatek/virt to /drivers/virt on next version.
> 
> The reason we put it under our soc/ is that the drver is highly
> propietary for mediatek's product and for aarch64 only. Maybe it's not
> general enough to put in under /drivers/virt.

This is the same reason why mediatek-drm is in drivers/gpu/drm/ and the same why
mediatek-cpufreq is in drivers/cpufreq/.

I know that this is a MediaTek specific implementation, but it *is* a hypervisor
driver, hence it belongs to the hypervisor drivers folder.
It's not even granted that this will not support other MediaTek architectures in
the future, but that's not a discussion to do right here and right now, and it's
anyway irrelevant in this moment.

By the way, good job with upstreaming your drivers targeting MediaTek Android SW!
I'm enthusiast to see that.

Regards,
Angelo