[v17,11/12] qapi/s390x/cpu topology: CPU_POLARIZATION_CHANGE qapi event

Commit Message

Pierre Morel March 9, 2023, 12:15 p.m. UTC

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 <[e-mail]>
---
 qapi/machine-target.json | 33 +++++++++++++++++++++++++++++++++
 hw/s390x/cpu-topology.c  |  2 ++
 2 files changed, 35 insertions(+)

Patch

diff --git a/qapi/machine-target.json b/qapi/machine-target.json
index 43e82cf071..fe6c432a8b 100644
--- a/qapi/machine-target.json
+++ b/qapi/machine-target.json
@@ -391,3 +391,36 @@ 
   'features': [ 'unstable' ],
   'if': { 'all': [ 'TARGET_S390X' , 'CONFIG_KVM' ] }
 }
+
+##
+# @CPU_POLARIZATION_CHANGE:
+#
+# Emitted when the guest asks to change the polarization.
+#
+# @polarization: polarization specified by the guest
+#
+# Features:
+# @unstable: This command may still be modified.
+#
+# 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.
+#
+# Since: 8.0
+#
+# Example:
+#
+# <- { "event": "CPU_POLARIZATION_CHANGE",
+#      "data": { "polarization": 0 },
+#      "timestamp": { "seconds": 1401385907, "microseconds": 422329 } }
+##
+{ 'event': 'CPU_POLARIZATION_CHANGE',
+  'data': { 'polarization': 'CpuS390Polarization' },
+  'features': [ 'unstable' ],
+  'if': { 'all': [ 'TARGET_S390X', 'CONFIG_KVM' ] }
+}
diff --git a/hw/s390x/cpu-topology.c b/hw/s390x/cpu-topology.c
index 0bf0a3d36f..100f72aeb3 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"
 
 /*
  * s390_topology is used to keep the topology information.
@@ -157,6 +158,7 @@  void s390_handle_ptf(S390CPU *cpu, uint8_t r1, uintptr_t ra)
             s390_topology.polarization = fc;
             s390_cpu_topology_set_changed(true);
             s390_topology_set_cpus_entitlement(fc);
+            qapi_event_send_cpu_polarization_change(fc);
             setcc(cpu, 0);
         }
         break;