From 49a0dc9e670b7f67713a7f9115028a4a29fbd03b Mon Sep 17 00:00:00 2001
From: Cornelia Huck <cohuck@redhat.com>
Date: Thu, 5 Oct 2017 12:04:05 +0200
Subject: [PATCH 11/34] s390x/ais: for 2.10 stable: disable ais facility

RH-Author: Cornelia Huck <cohuck@redhat.com>
Message-id: <20171005120406.16642-2-cohuck@redhat.com>
Patchwork-id: 76818
O-Subject: [RHV7.5 qemu-kvm-ma PATCH 1/2] s390x/ais: for 2.10 stable: disable ais facility
Bugzilla: 1494548
RH-Acked-by: Thomas Huth <thuth@redhat.com>
RH-Acked-by: Jens Freimann <jfreimann@redhat.com>
RH-Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

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

The migration interface for ais was introduced with kernel 4.13
but the capability itself had been active since 4.12. As migration
support is considered necessary lets disable ais in the 2.10
stable version. A proper fix and re-enablement will be done
for qemu 2.11.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Message-Id: <20170921140834.14233-2-borntraeger@de.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
(cherry picked from commit 3f2d07b3b01ea61126b382633ab4006320923048)
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
 target/s390x/kvm.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c
index c4c5791..eb0dbb3 100644
--- a/target/s390x/kvm.c
+++ b/target/s390x/kvm.c
@@ -308,8 +308,13 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
         }
     }
 
-    /* Try to enable AIS facility */
-    kvm_vm_enable_cap(s, KVM_CAP_S390_AIS, 0);
+    /*
+     * The migration interface for ais was introduced with kernel 4.13
+     * but the capability itself had been active since 4.12. As migration
+     * support is considered necessary let's disable ais in the 2.10
+     * machine.
+     */
+    /* kvm_vm_enable_cap(s, KVM_CAP_S390_AIS, 0); */
 
     qemu_mutex_init(&qemu_sigp_mutex);
 
-- 
1.8.3.1