OSDOCS#13000: Clarify platforms for CP and nodepools in IBM-Z/P

Author: xenolinux

hosted_control_planes/hosted-control-planes-release-notes.adoc

@@ -138,6 +138,11 @@ To resolve these issues, configure the DNS server settings for a dual stack netw
 
 Features which are Generally Available (GA) are fully supported and are suitable for production use. Technology Preview (TP) features are experimental features and are not intended for production use. For more information about TP features, see the link:https://access.redhat.com/support/offerings/techpreview[Technology Preview scope of support on the Red Hat Customer Portal].
 
+[IMPORTANT]
+====
+For {ibm-power-title} and {ibm-z-title}, you must run the control plane on machine types based on 64-bit x86 architecture, and node pools on {ibm-power-title} or {ibm-z-title}.
+====
+
 See the following table to know about {hcp} GA and TP features:
 
 .{hcp-capital} GA and TP tracker

modules/hcp-support-matrix.adoc

@@ -84,7 +84,14 @@ The following table maps {mce-short} versions to the hosted cluster versions tha
 [id="hcp-matrix-platform_{context}"]
 == Hosted cluster platform support
 
-The following table indicates which {product-title} versions are supported for each platform of {hcp}. In the table, _Management cluster version_ refers to the {product-title} version where the {mce-short} is enabled:
+The following table indicates which {product-title} versions are supported for each platform of {hcp}.
+
+[IMPORTANT]
+====
+For {ibm-power-title} and {ibm-z-title}, you must run the control plane on machine types based on 64-bit x86 architecture, and node pools on {ibm-power-title} or {ibm-z-title}.
+====
+
+In the following table, Management cluster version refers to the {product-title} version where the {mce-short} is enabled:
 
 .Required {product-title} versions for platforms
 [cols="3",options="header"]