KVM: s390: infrastructure to kick vcpus out of guest state

To ensure vcpu's come out of guest context in certain cases this patch adds a
s390 specific way to kick them out of guest context. Currently it kicks them
out to rerun the vcpu_run path in the s390 code, but the mechanism itself is
expandable and with a new flag we could also add e.g. kicks to userspace etc.

Signed-off-by: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 9 insertions, 3 deletions

diff --git a/arch/s390/kvm/intercept.c b/arch/s390/kvm/intercept.c
index 98997ccba501..0732ab4305f4 100644
--- a/arch/s390/kvm/intercept.c
+++ b/arch/s390/kvm/intercept.c
@@ -128,7 +128,7 @@ static int handle_noop(struct kvm_vcpu *vcpu)
 
 static int handle_stop(struct kvm_vcpu *vcpu)
 {
-        int rc;
+        int rc = 0;
 
         vcpu->stat.exit_stop_request++;
         atomic_clear_mask(CPUSTAT_RUNNING, &vcpu->arch.sie_block->cpuflags);
@@ -141,12 +141,18 @@ static int handle_stop(struct kvm_vcpu *vcpu)
                         rc = -ENOTSUPP;
         }
 
+        if (vcpu->arch.local_int.action_bits & ACTION_RELOADVCPU_ON_STOP) {
+                vcpu->arch.local_int.action_bits &= ~ACTION_RELOADVCPU_ON_STOP;
+                rc = SIE_INTERCEPT_RERUNVCPU;
+                vcpu->run->exit_reason = KVM_EXIT_INTR;
+        }
+
         if (vcpu->arch.local_int.action_bits & ACTION_STOP_ON_STOP) {
                 vcpu->arch.local_int.action_bits &= ~ACTION_STOP_ON_STOP;
                 VCPU_EVENT(vcpu, 3, "%s", "cpu stopped");
                 rc = -ENOTSUPP;
-        } else
-                rc = 0;
+        }
+
         spin_unlock_bh(&vcpu->arch.local_int.lock);
         return rc;
 }