Merge pull request #88929 from ousleyp/cnv-52365

CNV#52365: s390x compatibility TP notes

Author: ousleyp

virt/install/preparing-cluster-for-virt.adoc

@@ -52,6 +52,16 @@ include::snippets/technology-preview.adoc[]
 :!FeatureName:
 endif::[]
 --
+
+* {ibm-z-name} or {ibm-linuxone-name} (s390x architecture) systems where an {product-title} cluster is installed in a logical partition (LPAR). See xref:../../installing/installing_ibm_z/preparing-to-install-on-ibm-z.adoc#preparing-to-install-on-ibm-z_preparing-to-install-on-ibm-z[Preparing to install on {ibm-z-title} and {ibm-linuxone-title}].
++
+--
+ifdef::openshift-enterprise[]
+:FeatureName: Using {VirtProductName} in a cluster deployed on s390x architecture
+include::snippets/technology-preview.adoc[]
+:!FeatureName:
+endif::[]
+--
 endif::openshift-rosa,openshift-dedicated[]
 
 ifdef::openshift-rosa,openshift-dedicated[]
@@ -70,6 +80,61 @@ include::modules/virt-aws-bm.adoc[leveloffset=+2]
 * xref:../../virt/vm_networking/virt-connecting-vm-to-ovn-secondary-network.adoc#virt-connecting-vm-to-ovn-secondary-network[Connecting a virtual machine to an OVN-Kubernetes secondary network]
 * xref:../../virt/vm_networking/virt-exposing-vm-with-service.adoc#virt-exposing-vm-with-service[Exposing a virtual machine by using a service]
 
+// Hiding in ROSA/OSD - todo: double check this
+ifndef::openshift-rosa,openshift-dedicated[]
+[id="ibm-z-linuxone-compatibility_{context}"]
+=== {ibm-z-title} and {ibm-linuxone-title} compatibility
+
+You can use {VirtProductName} in an {product-title} cluster that is installed in a logical partition (LPAR) on an {ibm-z-name} or {ibm-linuxone-name} (s390x architecture) system.
+
+ifdef::openshift-enterprise[]
+:FeatureName: Using {VirtProductName} in a cluster deployed on s390x architecture
+include::snippets/technology-preview.adoc[]
+:!FeatureName:
+endif::[]
+
+Some features are not currently available on s390x architecture, while others require workarounds or procedural changes. These lists are subject to change.
+
+[discrete]
+[id="currently-unavailable-ibm-z_{context}"]
+==== Currently unavailable features
+
+The following features are not available or do not function on s390x architecture:
+
+* Memory hot plugging and hot unplugging
+* Watchdog devices
+* Node Health Check Operator
+* SR-IOV Operator
+* virtual Trusted Platform Module (vTPM) devices
+* {pipelines-title} tasks
+* UEFI mode for VMs
+* PCI passthrough
+* USB host passthrough
+* Configuring virtual GPUs
+* {VirtProductName} cluster checkup framework
+* Creating and managing Windows VMs
+
+[discrete]
+[id="functionality-differences_{context}"]
+==== Functionality differences
+
+The following features are available for use on s390x architecture but function differently or require procedural changes:
+
+* When xref:../../virt/managing_vms/virt-delete-vms.adoc#virt-delete-vm-web_virt-delete-vms[deleting a virtual machine by using the web console], the *grace period* option is ignored.
+
+* When xref:../../virt/managing_vms/advanced_vm_management/virt-configuring-default-cpu-model.adoc#virt-configuring-default-cpu-model_virt-configuring-default-cpu-model[configuring the default CPU model], the `spec.defaultCPUModel` value is `"gen15b"` for an {ibm-z-title} cluster.
+
+* When xref:../../virt/vm_networking/virt-hot-plugging-network-interfaces.adoc#virt-hot-plugging-network-interfaces[hot plugging secondary network interfaces], the `virtctl migrate <vm_name>` command does not migrate the VM. As a workaround, restart the VM by running the following command:
++
+[source,terminal]
+----
+$ virtctl restart <vm_name>
+----
+
+* When xref:../../virt/monitoring/virt-exposing-downward-metrics.adoc#virt-configuring-downward-metrics_virt-using-downward-metrics_virt-exposing-downward-metrics[configuring a downward metrics device], if you use a VM preference, the `spec.preference.name` value must be set to `rhel.9.s390x` or another available preference with the format `*.s390x`.
+
+endif::openshift-rosa,openshift-dedicated[]
+
 // Section is in assembly so that we can use xrefs
 [id="virt-hardware-os-requirements_preparing-cluster-for-virt"]
 == Hardware and operating system requirements