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Subject: Re: [PATCH] arch/s390/configs: Change CONFIG_VIRTIO_CONSOLE to "m"
To:     Thomas Huth <thuth@redhat.com>, linux-s390@vger.kernel.org,
        Heiko Carstens <hca@linux.ibm.com>
Cc:     linux-kernel@vger.kernel.org, Vasily Gorbik <gor@linux.ibm.com>,
        Marc Hartmayer <mhartmay@linux.ibm.com>,
        Halil Pasic <pasic@linux.ibm.com>, cohuck@redhat.com
References: <20210428082442.321327-1-thuth@redhat.com>
From:   Christian Borntraeger <borntraeger@de.ibm.com>
Message-ID: <c015ef3f-ff88-113b-a089-e2af9202399a@de.ibm.com>
Date:   Wed, 28 Apr 2021 10:31:54 +0200
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On 28.04.21 10:24, Thomas Huth wrote:
> In former times, the virtio-console code had to be compiled into
> the kernel since the old guest virtio transport had some hard de-
> pendencies. But since the old virtio transport has been removed in
> commit 7fb2b2d51244 ("s390/virtio: remove the old KVM virtio transport"),
> we do not have this limitation anymore.
> Commit bb533ec8bacd ("s390/config: do not select VIRTIO_CONSOLE via
> Kconfig") then also lifted the hard setting in the Kconfig system, so
> we can finally switch the CONFIG_VIRTIO_CONSOLE knob to compile this
> driver as a module now, making it more flexible for the user to only
> load it if it is really required.

Isnt that a distro specific decision? I would be perfectly fine to have
this change in Fedora, Redhat and co. Not so sure about defconfig.
We often use the defconfig in our CI and development things to have a
kernel config that boots up fine, even without a ramdisk. I agree that
virtio console is no longer really the most important console but does
it really hurt? Is any distro using the defconfig unmodified?

> 
> Signed-off-by: Thomas Huth <thuth@redhat.com>
> ---
>   arch/s390/configs/debug_defconfig | 2 +-
>   arch/s390/configs/defconfig       | 2 +-
>   2 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/s390/configs/debug_defconfig b/arch/s390/configs/debug_defconfig
> index dc0b69058ac4..04ce0edd0b31 100644
> --- a/arch/s390/configs/debug_defconfig
> +++ b/arch/s390/configs/debug_defconfig
> @@ -548,7 +548,7 @@ CONFIG_INPUT_EVDEV=y
>   # CONFIG_INPUT_MOUSE is not set
>   # CONFIG_SERIO is not set
>   CONFIG_LEGACY_PTY_COUNT=0
> -CONFIG_VIRTIO_CONSOLE=y
> +CONFIG_VIRTIO_CONSOLE=m
>   CONFIG_HW_RANDOM_VIRTIO=m
>   CONFIG_RAW_DRIVER=m
>   CONFIG_HANGCHECK_TIMER=m
> diff --git a/arch/s390/configs/defconfig b/arch/s390/configs/defconfig
> index 320379da96d9..e448711eff8d 100644
> --- a/arch/s390/configs/defconfig
> +++ b/arch/s390/configs/defconfig
> @@ -540,7 +540,7 @@ CONFIG_INPUT_EVDEV=y
>   # CONFIG_INPUT_MOUSE is not set
>   # CONFIG_SERIO is not set
>   CONFIG_LEGACY_PTY_COUNT=0
> -CONFIG_VIRTIO_CONSOLE=y
> +CONFIG_VIRTIO_CONSOLE=m
>   CONFIG_HW_RANDOM_VIRTIO=m
>   CONFIG_RAW_DRIVER=m
>   CONFIG_HANGCHECK_TIMER=m
>