On 22/02/2023 15.21, Pierre Morel wrote:
When the guest asks to change the polarization this change
is forwarded to the admin using QAPI.
The admin is supposed to take according decisions concerning
CPU provisioning.
I still find it weird talking about "the admin" here. I don't think any
human will monitor this event to take action on it. Maybe rather talk about
the "upper layer" (libvirt) or whatever you have in mind to monitor this event?
diff --git a/qapi/machine-target.json b/qapi/machine-target.json
index baa9d273cf..e7a9049c1f 100644
--- a/qapi/machine-target.json
+++ b/qapi/machine-target.json
@@ -389,3 +389,37 @@
'features': [ 'unstable' ],
'if': { 'all': [ 'TARGET_S390X' ] }
}
+
+##
+# @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 } }
+#
I'd remove the final empty line.
+##
+{ 'event': 'CPU_POLARIZATION_CHANGE',
+ 'data': { 'polarization': 'CpuS390Polarization' },
+ 'features': [ 'unstable' ],
+ 'if': { 'all': [ 'TARGET_S390X', 'CONFIG_KVM' ] }
+}
Thomas
