From 290110732de7db0dd2800b93250c773daeef8e05 Mon Sep 17 00:00:00 2001
From: SNiemann15 <sniemann@redhat.com>
Date: Thu, 5 Jun 2025 12:24:01 +0200
Subject: [PATCH] Watchdog add support for IBM Z

---
 modules/virt-defining-watchdog-device-vm.adoc | 15 ++++++++-------
 modules/virt-installing-watchdog-agent.adoc   | 14 ++++++++++++++
 2 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/modules/virt-defining-watchdog-device-vm.adoc b/modules/virt-defining-watchdog-device-vm.adoc
index 63b1e841957e..f6eba87db8f7 100644
--- a/modules/virt-defining-watchdog-device-vm.adoc
+++ b/modules/virt-defining-watchdog-device-vm.adoc
@@ -10,7 +10,7 @@ You configure a watchdog device for the virtual machine (VM).
 
 .Prerequisites
 
-* The VM must have kernel support for an `i6300esb` watchdog device. {op-system-base-full} images support `i6300esb`.
+* For `x86` systems, the VM must use a kernel that works with the `i6300esb` watchdog device. If you use `s390x` architecture, the kernel must be enabled for `diag288`. {op-system-base-full} images support `i6300esb` and `diag288`.
 * You have installed the {oc-first}.
 
 .Procedure
@@ -23,26 +23,27 @@ apiVersion: kubevirt.io/v1
 kind: VirtualMachine
 metadata:
   labels:
-    kubevirt.io/vm: vm2-rhel84-watchdog
+    kubevirt.io/vm: <vm-label>
   name: <vm-name>
 spec:
   runStrategy: Halted
   template:
     metadata:
       labels:
-        kubevirt.io/vm: vm2-rhel84-watchdog
+        kubevirt.io/vm: <vm-label>
     spec:
       domain:
         devices:
           watchdog:
             name: <watchdog>
-            i6300esb:
-              action: "poweroff" <1>
+            <watchdog-device-model>: <1>
+              action: "poweroff" <2>
 # ...
 ----
-<1> Specify `poweroff`, `reset`, or `shutdown`.
+<1> The watchdog device model to use. For `x86` specify `i6300esb`. For `s390x` specify `diag288`.
+<2> Specify `poweroff`, `reset`, or `shutdown`. The `shutdown` action requires that the guest virtual machine is responsive to ACPI signals. Therefore, using `shutdown` is not recommended.
 +
-The example above configures the `i6300esb` watchdog device on a RHEL8 VM with the poweroff action and exposes the device as `/dev/watchdog`.
+The example above configures the watchdog device on a VM with the `poweroff` action and exposes the device as `/dev/watchdog`.
 +
 This device can now be used by the watchdog binary.
 
diff --git a/modules/virt-installing-watchdog-agent.adoc b/modules/virt-installing-watchdog-agent.adoc
index 9a21f4111a1a..b8fcdb5c9257 100644
--- a/modules/virt-installing-watchdog-agent.adoc
+++ b/modules/virt-installing-watchdog-agent.adoc
@@ -12,6 +12,20 @@ You install the watchdog agent on the guest and start the `watchdog` service.
 
 . Log in to the virtual machine as root user.
 
+. This step is only required when installing on {ibm-z-name} (`s390x`). Enable `watchdog` by running the following command:
++
+[source,terminal]
+----
+# modprobe diag288_wdt
+----
+
+. Verify that the `/dev/watchdog` file path is present in the VM by running the following command:
++
+[source,terminal]
+----
+# ls /dev/watchdog
+----
+
 . Install the `watchdog` package and its dependencies:
 +
 [source,terminal]