packages/kata-runtime: alow arbitrary CDI annotations

As discussed via Teams, there is no sense in checking CDI annotations if the agent doesn't care about them anyway. This allows arbitrary CDI annotations in the policy.

packages/by-name/kata/kata-runtime/0021-runtime-remove-CDI-annotations.patch

@@ -0,0 +1,40 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Moritz Sanft <[email protected]>
+Date: Fri, 7 Feb 2025 13:12:28 +0100
+Subject: [PATCH] runtime: remove CDI annotations
+
+We want to remove CDI annotations before they get to the agent, as they should only influence VM creation. Passing them to the agent is likely to create problems in policy checking, as they are often dynamically injected.
+---
+ src/runtime/virtcontainers/kata_agent.go | 12 ++++++++++++
+ 1 file changed, 12 insertions(+)
+
+diff --git a/src/runtime/virtcontainers/kata_agent.go b/src/runtime/virtcontainers/kata_agent.go
+index 9a794392b927fc8fa231a72ce35bc3fcb2773d85..5e3548774154585251e192743b78363c53a00019 100644
+--- a/src/runtime/virtcontainers/kata_agent.go
++++ b/src/runtime/virtcontainers/kata_agent.go
+@@ -14,6 +14,7 @@ import (
+ 	"os"
+ 	"path"
+ 	"path/filepath"
++	"regexp"
+ 	"strconv"
+ 	"strings"
+ 	"sync"
+@@ -1080,6 +1081,17 @@ func (k *kataAgent) constrainGRPCSpec(grpcSpec *grpc.Spec, passSeccomp bool, dis
+ 		grpcSpec.Linux.Devices = linuxDevices
+ 	}
+
++	cdiRegexp, err := regexp.Compile(`$cdi\.k8s\.io\/.*^`)
++	if err != nil {
++		k.Logger().WithError(err).Error("compile CDI annotation regexp")
++	}
++
++	for key := range grpcSpec.Annotations {
++		if cdiRegexp.MatchString(key) {
++			delete(grpcSpec.Annotations, key)
++		}
++	}
++
+ 	return nil
+ }
+

packages/by-name/kata/kata-runtime/package.nix

@@ -133,6 +133,12 @@ buildGoModule rec {
       # * https://github.com/kata-containers/kata-containers/issues/10680
       # * https://github.com/kata-containers/kata-containers/pull/10818
       ./0020-agent-clear-log-pipes-if-denied-by-policy.patch
+
+      # This removes CDI annotations from the OCI spec before it is passed to the agent,
+      # which helps with policy handling of the (oftentimes dynamic) CDI annotations.
+      # TODO(msanft): Get native CDI working, which will allow us to drop this patch / undo the revert.
+      # See https://dev.azure.com/Edgeless/Edgeless/_workitems/edit/5061
+      ./0021-runtime-remove-CDI-annotations.patch
     ];
   };