[PATCH 1/3] kvm-s390: Fix printk on SIGP set arch

[Christian Borntraeger <borntraeger@de.ibm.com>]

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

KVM on s390 does not support the ESA/390 architecture. We refuse to 
change the architecture mode and print a warning. While testing a
crashme for kvm, I spotted two problems with the printk:

o A malicious can flood host dmesg
o There was no newline at the end of the printk

This patch fixes both problems.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
---
 arch/s390/kvm/sigp.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

Index: kvm/arch/s390/kvm/sigp.c
===================================================================
--- kvm.orig/arch/s390/kvm/sigp.c
+++ kvm/arch/s390/kvm/sigp.c
@@ -153,8 +153,9 @@ static int __sigp_set_arch(struct kvm_vc
 
 	switch (parameter & 0xff) {
 	case 0:
-		printk(KERN_WARNING "kvm: request to switch to ESA/390 mode"
-							" not supported");
+		if (printk_ratelimit())
+			printk(KERN_WARNING "kvm: request to switch to ESA/390"
+					    " mode not supported\n");
 		rc = 3; /* not operational */
 		break;
 	case 1: