diff mbox series

[PULL,08/15] target/s390x/kvm: Enable adapter interruption suppression again

Message ID 20200127122016.18752-9-cohuck@redhat.com (mailing list archive)
State New, archived
Headers show
Series [PULL,01/15] s390x/sclp.c: remove unneeded label in sclp_service_call() | expand

Commit Message

Cornelia Huck Jan. 27, 2020, 12:20 p.m. UTC 
From: Thomas Huth <thuth@redhat.com>

The AIS feature has been disabled late in the v2.10 development cycle since
there were some issues with migration (see commit 3f2d07b3b01ea61126b -
"s390x/ais: for 2.10 stable: disable ais facility"). We originally wanted
to enable it again for newer machine types, but apparently we forgot to do
this so far. Let's do it now for the machines that support proper CPU models.

Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1756946
Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20200122101437.5069-1-thuth@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
---
 target/s390x/kvm.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c
index 15260aeb9aac..30112e529c2e 100644
--- a/target/s390x/kvm.c
+++ b/target/s390x/kvm.c
@@ -365,10 +365,13 @@  int kvm_arch_init(MachineState *ms, KVMState *s)
     /*
      * 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.
+     * support is considered necessary, we only try to enable this for
+     * newer machine types if KVM_CAP_S390_AIS_MIGRATION is available.
      */
-    /* kvm_vm_enable_cap(s, KVM_CAP_S390_AIS, 0); */
+    if (cpu_model_allowed() && kvm_kernel_irqchip_allowed() &&
+        kvm_check_extension(s, KVM_CAP_S390_AIS_MIGRATION)) {
+        kvm_vm_enable_cap(s, KVM_CAP_S390_AIS, 0);
+    }
 
     kvm_set_max_memslot_size(KVM_SLOT_MAX_BYTES);
     return 0;