[PATCH v15 10/11] qapi/s390x/cpu topology: CPU_POLARITY_CHANGE qapi event

[Pierre Morel <pmorel@xxxxxxxxxxxxx>]

When the guest asks to change the polarity this change
is forwarded to the admin using QAPI.
The admin is supposed to take according decisions concerning
CPU provisioning.

Signed-off-by: Pierre Morel <pmorel@xxxxxxxxxxxxx>
---
 qapi/machine-target.json | 30 ++++++++++++++++++++++++++++++
 hw/s390x/cpu-topology.c  |  2 ++
 2 files changed, 32 insertions(+)

diff --git a/qapi/machine-target.json b/qapi/machine-target.json
index 58df0f5061..5883c3b020 100644
--- a/qapi/machine-target.json
+++ b/qapi/machine-target.json
@@ -371,3 +371,33 @@
   },
   'if': { 'all': [ 'TARGET_S390X', 'CONFIG_KVM' ] }
 }
+
+##
+# @CPU_POLARITY_CHANGE:
+#
+# Emitted when the guest asks to change the polarity.
+#
+# @polarity: polarity specified by the guest
+#
+# The guest can tell the host (via the PTF instruction) whether the
+# CPUs should be provisioned using horizontal or vertical polarity.
+#
+# On horizontal polarity the host is expected to provision all vCPUs
+# equally.
+# On vertical polarity the host can provision each vCPU differently.
+# The guest will get information on the details of the provisioning
+# the next time it uses the STSI(15) instruction.
+#
+# Since: 8.0
+#
+# Example:
+#
+# <- { "event": "CPU_POLARITY_CHANGE",
+#      "data": { "polarity": 0 },
+#      "timestamp": { "seconds": 1401385907, "microseconds": 422329 } }
+#
+##
+{ 'event': 'CPU_POLARITY_CHANGE',
+  'data': { 'polarity': 'int' },
+   'if': { 'all': [ 'TARGET_S390X', 'CONFIG_KVM'] }
+}
diff --git a/hw/s390x/cpu-topology.c b/hw/s390x/cpu-topology.c
index 6c50050991..2f8e1b60cf 100644
--- a/hw/s390x/cpu-topology.c
+++ b/hw/s390x/cpu-topology.c
@@ -19,6 +19,7 @@
 #include "hw/s390x/s390-virtio-ccw.h"
 #include "hw/s390x/cpu-topology.h"
 #include "qapi/qapi-commands-machine-target.h"
+#include "qapi/qapi-events-machine-target.h"
 #include "qapi/qmp/qdict.h"
 #include "monitor/hmp.h"
 #include "monitor/monitor.h"
@@ -163,6 +164,7 @@ void s390_handle_ptf(S390CPU *cpu, uint8_t r1, uintptr_t ra)
             s390_topology.polarity = fc;
             s390_cpu_topology_set_modified();
             s390_topology_set_cpus_polarity(fc);
+            qapi_event_send_cpu_polarity_change(fc);
             setcc(cpu, 0);
         }
         break;
-- 
2.31.1