Document DHCP backend validation matrix

docs/source/developers/guides/code/dhcp_backend_validation_matrix.rst

@@ -34,6 +34,13 @@ Run these checks for every DHCP backend change before live validation:
 * Perl syntax checks for changed DHCP modules
 * unit tests for backend selection, range handling, boot policy, and renderer
   behavior
+* Kea version-aware renderer checks when client classification is touched:
+
+  * Kea 2.4 output must use ``only-if-required`` and
+    ``require-client-classes``
+  * Kea 3.x output must use ``only-in-additional-list`` and
+    ``evaluate-additional-classes``
+
 * backend-native configuration validation:
 
   * ``dhcpd -t -cf <config>`` for ISC
@@ -114,6 +121,10 @@ The current KVM validation hosts are:
 * ``rome01.local.versatushpc.com.br`` for ``x86_64``
 * ``power.local.versatushpc.com.br`` for ``ppc64le``
 
+Validation access should use the ``builder`` account and the
+``id_ed25519_reposync`` SSH key. Avoid relying on ad-hoc root login or
+one-off cloud-init keys when recording repeatable validation procedure.
+
 Known Exceptions
 ----------------
 
@@ -125,8 +136,56 @@ Current exceptions:
 * Ubuntu 22.04 LTS ISC OMAPI/``omshell`` host reservation updates are blocked by
   issue ``#11``. The failure reproduces on upstream ``master`` and is not caused
   by the Kea backend work.
-* EL10 ``ppc64le`` currently reaches xCAT Genesis, but full POWER validation is
-  blocked by a preexisting ``genesis.kernel.ppc64`` issue unrelated to Kea.
+* EL10 ``ppc64le`` Kea configuration and DHCP unit validation pass. Full POWER
+  image boot validation can still be blocked by a preexisting
+  ``genesis.kernel.ppc64`` invalid-ELF issue unrelated to Kea.
+
+Current PR Validation Snapshot
+------------------------------
+
+As of April 23, 2026, the ``kea-dhcp-backend`` PR has the following DHCP
+backend validation result:
+
+.. list-table::
+   :header-rows: 1
+   :widths: 16 10 10 20 44
+
+   * - Platform
+     - Arch
+     - Backend
+     - Result
+     - Notes
+   * - EL9
+     - ``x86_64``
+     - ``ISC``
+     - Pass
+     - ``site.dhcpbackend=auto`` selected ``isc``; legacy DHCP unit subset
+       passed.
+   * - Ubuntu 22.04 LTS
+     - ``x86_64``
+     - ``ISC``
+     - Pass with known exception
+     - ``site.dhcpbackend=auto`` selected ``isc``; legacy DHCP unit subset
+       passed. OMAPI reservation updates remain tracked by issue ``#11``.
+   * - EL10
+     - ``x86_64``
+     - ``Kea 3.0.1``
+     - Pass
+     - Renderer emitted ``evaluate-additional-classes`` and
+       ``only-in-additional-list``; ``kea-dhcp4 -t`` passed.
+   * - Ubuntu 24.04 LTS
+     - ``x86_64``
+     - ``Kea 2.4.1``
+     - Pass
+     - Renderer emitted ``require-client-classes`` and ``only-if-required``;
+       full DHCP unit suite and ``kea-dhcp4 -t`` passed.
+   * - EL10
+     - ``ppc64le``
+     - ``Kea 3.0.1``
+     - Pass
+     - Renderer emitted ``evaluate-additional-classes`` and
+       ``only-in-additional-list``; full DHCP unit suite and ``kea-dhcp4 -t``
+       passed.
 
 Reporting Rule
 --------------

docs/source/developers/guides/code/kea_dhcp_backend_plan.rst

@@ -278,6 +278,11 @@ Configuration validation tests:
 * ``kea-dhcp4 -t`` and ``kea-dhcp6 -t`` for Kea DHCP output
 * ``kea-dhcp-ddns -t`` for D2 output
 * ``kea-ctrl-agent -t`` for Control Agent output
+* Kea client-class renderer output for both supported syntax generations:
+
+  * Kea 2.4 uses ``only-if-required`` and ``require-client-classes``
+  * Kea 3.x uses ``only-in-additional-list`` and
+    ``evaluate-additional-classes``
 
 Backend selection tests:
 
@@ -328,6 +333,8 @@ Open test infrastructure details to confirm:
   available
 * whether nested or privileged test guests can run DHCP client and PXE tests
 * cleanup expectations for temporary VMs, networks, and storage volumes
+* the ``builder`` account and ``id_ed25519_reposync`` SSH key are available for
+  repeatable validation access
 
 Manual Validation Snapshot
 --------------------------
@@ -347,9 +354,12 @@ and Kea backends:
   xNBA network script, and Genesis fetch. Per-node OMAPI reservation updates on
   Jammy still fail with ``omshell`` descriptor errors and appear to be a
   preexisting Ubuntu-specific ISC issue outside the Kea scope.
-* EL10 plus Kea on ppc64le: Kea and the Kea boot handoff reached xCAT Genesis,
-  but Genesis failed loading ``genesis.kernel.ppc64`` because of a preexisting
-  invalid ELF image issue unrelated to Kea.
+* EL10 plus Kea on ppc64le: passed Kea 3.x renderer validation with
+  ``evaluate-additional-classes`` and ``only-in-additional-list``; passed
+  ``kea-dhcp4 -t``; passed the full DHCP unit suite on ppc64le after installing
+  the Perl test harness packages on the VM. Earlier full POWER image boot
+  validation reached xCAT Genesis, then failed loading ``genesis.kernel.ppc64``
+  because of a preexisting invalid ELF image issue unrelated to Kea.
 
 Implementation Order
 --------------------