qapi/s390x/cpu topology: CPU_POLARIZATION_CHANGE QAPI event

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

Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
Co-developed-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
Message-ID: <20231016183925.2384704-13-nsg@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>

diff --git a/hw/s390x/cpu-topology.c b/hw/s390x/cpu-topology.c
index f3771f50455d7b49eb910e39c36dcc582ef6381a..327bccea4f82cd7f52594708ef26d47b7b651c86 100644 (file)
--- a/hw/s390x/cpu-topology.c
+++ b/hw/s390x/cpu-topology.c
@@ -24,6 +24,7 @@
 #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"
 
 /*
  * s390_topology is used to keep the topology information.
@@ -136,6 +137,7 @@ void s390_handle_ptf(S390CPU *cpu, uint8_t r1, uintptr_t ra)
         } else {
             s390_topology.polarization = polarization;
             s390_cpu_topology_set_changed(true);
+            qapi_event_send_cpu_polarization_change(polarization);
             setcc(cpu, 0);
         }
         break;

diff --git a/qapi/machine-target.json b/qapi/machine-target.json
index 7688f32ffa116e85c38b732609799e1063966b81..ac93a5f82c54f64a29a4ca5dfb9b9fc622ec54dd 100644 (file)
--- a/qapi/machine-target.json
+++ b/qapi/machine-target.json
@@ -417,3 +417,38 @@
   'features': [ 'unstable' ],
   'if': { 'all': [ 'TARGET_S390X' , 'CONFIG_KVM' ] }
 }
+
+##
+# @CPU_POLARIZATION_CHANGE:
+#
+# Emitted when the guest asks to change the polarization.
+#
+# The guest can tell the host (via the PTF instruction) whether the
+# CPUs should be provisioned using horizontal or vertical polarization.
+#
+# On horizontal polarization the host is expected to provision all vCPUs
+# equally.
+#
+# On vertical polarization 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.
+#
+# @polarization: polarization specified by the guest
+#
+# Features:
+#
+# @unstable: This event is experimental.
+#
+# Since: 8.2
+#
+# Example:
+#
+# <- { "event": "CPU_POLARIZATION_CHANGE",
+#      "data": { "polarization": "horizontal" },
+#      "timestamp": { "seconds": 1401385907, "microseconds": 422329 } }
+##
+{ 'event': 'CPU_POLARIZATION_CHANGE',
+  'data': { 'polarization': 'CpuS390Polarization' },
+  'features': [ 'unstable' ],
+  'if': { 'all': [ 'TARGET_S390X', 'CONFIG_KVM' ] }
+}