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Date:   Fri, 14 Apr 2023 10:51:59 +0200
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Subject: Re: [PATCH v1 3/6] soc: mediatek: virt: geniezone: Introduce
 GenieZone hypervisor support
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To:     =?UTF-8?B?WWktRGUgV3UgKOWQs+S4gOW+tyk=?= <Yi-De.Wu@mediatek.com>,
        "corbet@lwn.net" <corbet@lwn.net>,
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        "catalin.marinas@arm.com" <catalin.marinas@arm.com>,
        "krzysztof.kozlowski+dt@linaro.org" 
        <krzysztof.kozlowski+dt@linaro.org>,
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        <Yingshiuan.Pan@mediatek.com>,
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        "angelogioacchino.delregno@collabora.com" 
        <angelogioacchino.delregno@collabora.com>,
        "will@kernel.org" <will@kernel.org>,
        Trilok Soni <quic_tsoni@quicinc.com>
Cc:     "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
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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:   Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
In-Reply-To: <533a1a9b653cf63f1e5df7f95d1b23902809561d.camel@mediatek.com>
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On 14/04/2023 10:43, Yi-De Wu (吳一德) wrote:
> 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.

If virt folks reject the driver, because it is highly proprietary, then
it is not suitable for soc/mediatek either.

Your argument is actually not helping you. It's rather a proof that this
driver might not be suitable for Linux kernel at all.

>
https://android-review.googlesource.com/c/kernel/common/+/2447547/1..2/drivers/virt/geniezone/gzvm.h#b91

I don't see there anything suggesting moving to soc/mediatek. Comment
from Trilok (+Cc) suggests that your code is simply not portable. Write
code which is portable and properly organized.

Best regards,
Krzysztof