[PATCH 0/2] kvm-s390: small fixes

[PATCH 0/2] kvm-s390: small fixes

[Christian Borntraeger]

Hello Avi,

here are two small patches for kvm on s390:
1. kvm-s390: Fix guest kconfig for virtio
2. kvm-s390: change help text of guest Kconfig

Christian

[PATCH 1/2] kvm-s390: Fix guest kconfig for virtio

[Christian Borntraeger]

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.

CC: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
---
 drivers/s390/kvm/Makefile |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Index: kvm/drivers/s390/kvm/Makefile
===================================================================
--- kvm.orig/drivers/s390/kvm/Makefile
+++ kvm/drivers/s390/kvm/Makefile
@@ -6,4 +6,4 @@
 # it under the terms of the GNU General Public License (version 2 only)
 # as published by the Free Software Foundation.
 
-obj-$(CONFIG_VIRTIO) += kvm_virtio.o
+obj-$(CONFIG_S390_GUEST) += kvm_virtio.o

[PATCH 2/2] kvm-s390: change help text of guest Kconfig

[Christian Borntraeger]

The current help text for CONFIG_S390_GUEST is not very helpful.
Add more text.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
---
 arch/s390/Kconfig |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

Index: kvm/arch/s390/Kconfig
===================================================================
--- kvm.orig/arch/s390/Kconfig
+++ kvm/arch/s390/Kconfig
@@ -540,13 +540,16 @@ config ZFCPDUMP
 	  Refer to <file:Documentation/s390/zfcpdump.txt> for more details on this.
 
 config S390_GUEST
-bool "s390 guest support (EXPERIMENTAL)"
+bool "s390 guest support for KVM (EXPERIMENTAL)"
 	depends on 64BIT && EXPERIMENTAL
 	select VIRTIO
 	select VIRTIO_RING
 	select VIRTIO_CONSOLE
 	help
-	  Select this option if you want to run the kernel under s390 linux
+	  Select this option if you want to run the kernel as a guest under
+	  the KVM hypervisor. This will add detection for KVM as well  as a
+	  virtio transport. If KVM is detected, the virtio console will be
+	  the default console.
 endmenu
 
 source "net/Kconfig"

Re: [PATCH 1/2] kvm-s390: Fix guest kconfig for virtio

[Avi Kivity]

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.

Re: [PATCH 2/2] kvm-s390: change help text of guest Kconfig

[Avi Kivity]

Christian Borntraeger wrote:
> The current help text for CONFIG_S390_GUEST is not very helpful.
> Add more text.
>
>   

Doesn't apply (even with -C0)?  What tree are based on?

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

Re: [PATCH 1/2] kvm-s390: Fix guest kconfig for virtio

[Christian Borntraeger]

Am Dienstag, 15. Juli 2008 schrieb Avi Kivity:
> 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?

That is already the case. S390_GUEST has 

bool "s390 guest support (EXPERIMENTAL)"
        depends on 64BIT && EXPERIMENTAL
        select VIRTIO
        select VIRTIO_RING
[...]

Re: [PATCH 2/2] kvm-s390: change help text of guest Kconfig

[Christian Borntraeger]

Am Dienstag, 15. Juli 2008 schrieb Avi Kivity:
> Christian Borntraeger wrote:
> > The current help text for CONFIG_S390_GUEST is not very helpful.
> > Add more text.
> >
> >   
> 
> Doesn't apply (even with -C0)?  What tree are based on?

Hmm, I think the problem stems from the virtio_console patches which are in 
Rustys tree. They add an select statement to CONFIG_S390_GUEST. Lets drop 
this patch until Rustys tree is merged.

Christian