Merge pull request #77334 from openshift-cherrypick-robot/cherry-pick-76833-to-enterprise-4.16

[enterprise-4.16] CNV#29661: documentation for persistent nvram

modules/virt-configuring-vm-with-persistent-efi.adoc

@@ -0,0 +1,34 @@
+// Module included in the following assemblies:
+//
+// * virt/virtual_machines/advanced_vm_management/virt-uefi-mode-for-vms.adoc
+
+:_mod-docs-content-type: PROCEDURE
+[id="configuring-vm-with-persistent-efi_{context}"]
+= Configuring VMs with persistent EFI
+
+You can configure a VM to have EFI persistence enabled by editing its manifest file.
+
+.Prerequisites
+
+* `VMPersistentState` feature gate enabled.
+
+.Procedure
+
+* Edit the VM manifest file and save to apply settings.
++
+[source,yaml]
+----
+apiVersion: kubevirt.io/v1
+kind: VirtualMachine
+metadata:
+  name: vm
+spec:
+  template:
+    spec:
+      domain:
+        firmware:
+          bootloader:
+            efi:
+              persistent: true
+# ...
+----

modules/virt-enabling-persistent-efi.adoc

@@ -0,0 +1,24 @@
+// Module included in the following assemblies:
+//
+// * virt/virtual_machines/advanced_vm_management/virt-uefi-mode-for-vms.adoc
+
+:_mod-docs-content-type: PROCEDURE
+[id="virt-enabling-persistent-efi_{context}"]
+= Enabling persistent EFI
+
+You can enable EFI persistence in a VM by configuring an RWX storage class at the cluster level and adjusting the settings in the EFI section of the VM.
+
+.Prerequisites
+
+* You must have cluster administrator privileges.
+* You must have a storage class that supports RWX access mode and FS volume mode.
+
+.Procedure
+
+* Enable the `VMPersistentState` feature gate by running the following command:
++
+[source,terminal,subs="attributes+"]
+----
+$ oc patch hyperconverged kubevirt-hyperconverged -n {CNVNamespace} \
+  --type json -p '[{"op":"replace","path":"/spec/featureGates/VMPersistentState", "value": true}]'
+----

virt/virtual_machines/advanced_vm_management/virt-uefi-mode-for-vms.adoc

@@ -10,3 +10,5 @@ You can boot a virtual machine (VM) in Unified Extensible Firmware Interface (UE
 
 include::modules/virt-about-uefi-mode-for-vms.adoc[leveloffset=+1]
 include::modules/virt-booting-vms-uefi-mode.adoc[leveloffset=+1]
+include::modules/virt-enabling-persistent-efi.adoc[leveloffset=+1]
+include::modules/virt-configuring-vm-with-persistent-efi.adoc[leveloffset=+1]