From mboxrd@z Thu Jan  1 00:00:00 1970
From: Avi Kivity <avi@qumranet.com>
Subject: Re: [PATCH 1/2] kvm-s390: Fix guest kconfig for virtio
Date: Tue, 15 Jul 2008 13:57:00 +0300
Message-ID: <487C827C.3070303@qumranet.com>
References: <200807151056.40805.borntraeger@de.ibm.com> <200807151100.21769.borntraeger@de.ibm.com>
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Cc: kvm <kvm@vger.kernel.org>, Carsten Otte <cotte@de.ibm.com>,
	Cornelia Huck <cornelia.huck@de.ibm.com>
To: Christian Borntraeger <borntraeger@de.ibm.com>
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Christian Borntraeger wrote:
> Cornelia Huck noticed that a modular virtio without kvm guest support
> leads to a build error in the s390 virtio transport:
>
> CONFIG_VIRTIO=m leads to 
> ERROR: "vmem_add_mapping" [drivers/s390/kvm/kvm_virtio.ko] undefined!
> ERROR: "max_pfn" [drivers/s390/kvm/kvm_virtio.ko] undefined!
> ERROR: "vmem_remove_mapping" [drivers/s390/kvm/kvm_virtio.ko] undefined!
>
> The virtio transport only works with kvm guest support and only as a
> builtin. Lets change the build process of drivers/s390/kvm/kvm_virtio.c
> to depend on kvm guest support, which is also a bool.
>   

This leads to confusion if CONFIG_VIRTIO is unset but CONFIG_S390_GUEST 
is set.

What about having CONFIG_S390_GUEST select CONFIG_VIRTIO instead?

-- 
Do not meddle in the internals of kernels, for they are subtle and quick to panic.