From: David Hildenbrand <dahi@linux.vnet.ibm.com>
Date: Mon, 4 Apr 2016 13:57:08 +0000 (+0200)
Subject: KVM: s390: enable ibs only if available
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=09a400e78eaf02d8ab8e836edf864e1025c8e2d7;p=linux-beck.git

KVM: s390: enable ibs only if available

Let's enable interlock-and-broadcast suppression only if the facility is
actually available.

Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
---

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index d987eb8af059..ad93b40bfdc0 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -2789,6 +2789,8 @@ static void __disable_ibs_on_all_vcpus(struct kvm *kvm)
 
 static void __enable_ibs_on_vcpu(struct kvm_vcpu *vcpu)
 {
+	if (!sclp.has_ibs)
+		return;
 	kvm_check_request(KVM_REQ_DISABLE_IBS, vcpu);
 	kvm_s390_sync_request(KVM_REQ_ENABLE_IBS, vcpu);
 }