KVM: s390: Do not yield when target is already running
If the target is already running we do not need to yield.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
diff --git a/arch/s390/kvm/diag.c b/arch/s390/kvm/diag.c
index 609c55d..3fb54ec 100644
--- a/arch/s390/kvm/diag.c
+++ b/arch/s390/kvm/diag.c
@@ -168,6 +168,10 @@
if (!tcpu)
goto no_yield;
+ /* target already running */
+ if (READ_ONCE(tcpu->cpu) >= 0)
+ goto no_yield;
+
if (kvm_vcpu_yield_to(tcpu) <= 0)
goto no_yield;
