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Date:   Wed, 28 Apr 2021 23:29:03 +0200
From:   Heiko Carstens <hca@linux.ibm.com>
To:     Christian Borntraeger <borntraeger@de.ibm.com>
Cc:     Thomas Huth <thuth@redhat.com>, linux-s390@vger.kernel.org,
        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
Subject: Re: [PATCH] arch/s390/configs: Change CONFIG_VIRTIO_CONSOLE to "m"
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On Wed, Apr 28, 2021 at 11:03:22PM +0200, Christian Borntraeger wrote:
> On 28.04.21 11:30, Thomas Huth wrote:
> > On 28/04/2021 10.31, Christian Borntraeger wrote:
> > > 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.
> > 
> > Sure, I'll try to get it changed there, too.
> > 
> > > 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?
> > Well, it's about a default configuration that should be fine for
> > most users. I don't think that anybody really uses virtio-console
> > in a ramdisk already ... or are you really doing that in your CI?
> > If so, then please disregard my patch.
> 
> I think anybody uses the sclp console nowadays. The only question is, do
> we care about manual configs with virtio-console?

Not really. If it breaks someone's workflow we will know for sure
pretty soon. Therefore let's just change this.