KVM: s390: do store status after handling STOP_ON_STOP bit
Jens Freimann [Mon, 6 Feb 2012 09:59:03 +0000 (10:59 +0100)]
In handle_stop() handle the stop bit before doing the store status as
described for "Stop and Store Status" in the Principles of Operation.
We have to give up the local_int.lock before calling kvm store status
since it calls gmap_fault() which might sleep. Since local_int.lock
only protects local_int.* and not guest memory we can give up the lock.

Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

arch/s390/kvm/intercept.c

index 776ef83..3614565 100644 (file)
@@ -133,13 +133,6 @@ static int handle_stop(struct kvm_vcpu *vcpu)
 
        vcpu->stat.exit_stop_request++;
        spin_lock_bh(&vcpu->arch.local_int.lock);
-       if (vcpu->arch.local_int.action_bits & ACTION_STORE_ON_STOP) {
-               vcpu->arch.local_int.action_bits &= ~ACTION_STORE_ON_STOP;
-               rc = kvm_s390_vcpu_store_status(vcpu,
-                                                 KVM_S390_STORE_STATUS_NOADDR);
-               if (rc >= 0)
-                       rc = -EOPNOTSUPP;
-       }
 
        if (vcpu->arch.local_int.action_bits & ACTION_RELOADVCPU_ON_STOP) {
                vcpu->arch.local_int.action_bits &= ~ACTION_RELOADVCPU_ON_STOP;
@@ -155,7 +148,18 @@ static int handle_stop(struct kvm_vcpu *vcpu)
                rc = -EOPNOTSUPP;
        }
 
-       spin_unlock_bh(&vcpu->arch.local_int.lock);
+       if (vcpu->arch.local_int.action_bits & ACTION_STORE_ON_STOP) {
+               vcpu->arch.local_int.action_bits &= ~ACTION_STORE_ON_STOP;
+               /* store status must be called unlocked. Since local_int.lock
+                * only protects local_int.* and not guest memory we can give
+                * up the lock here */
+               spin_unlock_bh(&vcpu->arch.local_int.lock);
+               rc = kvm_s390_vcpu_store_status(vcpu,
+                                               KVM_S390_STORE_STATUS_NOADDR);
+               if (rc >= 0)
+                       rc = -EOPNOTSUPP;
+       } else
+               spin_unlock_bh(&vcpu->arch.local_int.lock);
        return rc;
 }