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

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

[Christian Borntraeger]

Hello Avi,

here are two small fixes against kvm.git

[PATCH 1/2] kvm-s390: Rework facility bits
[PATCH 2/2] kvm-s390: change help text of guest Kconfig

Patch 1 fixes potential problems with newer machines and Patch 2 is a
trivial help text change. I think both patches should be ok for 2.6.27.

Christian

[PATCH 1/2] kvm-s390: Rework facility bits

[Christian Borntraeger]

From: Christian Borntraeger <borntraeger@de.ibm.com>

Heiko Carstens pointed out, that its safer to activate working facilities
instead of disabling problematic facilities. The new code uses the host
facility bits and masks it with known good ones.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
---
 arch/s390/kvm/priv.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Index: kvm/arch/s390/kvm/priv.c
===================================================================
--- kvm.orig/arch/s390/kvm/priv.c
+++ kvm/arch/s390/kvm/priv.c
@@ -157,8 +157,8 @@ static int handle_stfl(struct kvm_vcpu *
 	int rc;
 
 	vcpu->stat.instruction_stfl++;
-	facility_list &= ~(1UL<<24); /* no stfle */
-	facility_list &= ~(1UL<<23); /* no large pages */
+	/* only pass the facility bits, which we can handle */
+	facility_list &= 0xfe00fff3;
 
 	rc = copy_to_guest(vcpu, offsetof(struct _lowcore, stfl_fac_list),
 			   &facility_list, sizeof(facility_list));

[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.
Lets 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
@@ -564,13 +564,16 @@ 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 0/2] kvm-s390: minor fixes

[Avi Kivity]

Christian Borntraeger wrote:
> Hello Avi,
>
> here are two small fixes against kvm.git
>
> [PATCH 1/2] kvm-s390: Rework facility bits
> [PATCH 2/2] kvm-s390: change help text of guest Kconfig
>
> Patch 1 fixes potential problems with newer machines and Patch 2 is a
> trivial help text change. I think both patches should be ok for 2.6.27.
>
>   

Applied both, and will queue for 2.6.27.

-- 
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.