diff --git a/tools/diff-kernel-config b/tools/diff-kernel-config
index 350b978a431..c433c63db74 100755
--- a/tools/diff-kernel-config
+++ b/tools/diff-kernel-config
@@ -31,7 +31,7 @@ bail() {
 
 usage() {
     cat <<EOF
-Usage: $0 -b GITREV_BEFORE -a GITREV_AFTER -o OUTPUT_DIR [-k KERNEL_VERSION] [-h]
+Usage: $0 -b GITREV_BEFORE -a GITREV_AFTER -o OUTPUT_DIR [-v VARIANT] [-r] [-h]
 Compare kernel configurations before and after a series of commits.
 
     -a, --after         new Git revision to compare from
@@ -40,6 +40,8 @@ Compare kernel configurations before and after a series of commits.
                         be given multiple times (optional, defaults to this list:
                         'aws-k8s-1.23', 'metal-k8s-1.23', 'aws-dev', 'metal-dev')
     -o, --output-dir    path to the output directory; must not exist yet
+    -r, --resume        resume work on a previous invocation; check which parts
+                        already exist in OUTPUT_DIR and skip builds accordingly
     -h, --help          show this help text
 
 Example invocation:
@@ -84,6 +86,8 @@ while [[ $# -gt 0 ]]; do
             shift; variants+=( "$1" ) ;;
         -o|--output-dir)
             shift; output_dir=$1 ;;
+        -r|--resume)
+            shift; resume=1 ;;
         -h|--help)
             usage; exit 0 ;;
         *)
@@ -102,7 +106,7 @@ done
 readonly variants
 
 [[ -n ${output_dir} ]] || usage_error 'require -o|--output-dir'
-[[ -e ${output_dir} ]] && bail "Output directory '${output_dir}' exists already, not touching it"
+[[ -e ${output_dir} && ! -v resume ]] && bail "Output directory '${output_dir}' exists already, not touching it"
 readonly output_dir
 
 # Validate and resolve the given before and after Git revisions. Resolving
@@ -163,6 +167,12 @@ for state in after before; do
         kernel_versions+=( "${kver}" )
 
         for arch in "${arches[@]}"; do
+            config_path=${output_dir}/config-${arch}-${variant}-${state}
+
+            if [[ -v resume && -e ${config_path} ]]; then
+                echo "${config_path} already exists, skipping"
+                continue
+            fi
 
             debug_id="state=${state} arch=${arch} variant=${variant} kernel=${kver}"
 
@@ -206,13 +216,12 @@ for state in after before; do
                     ;;
             esac
 
-            kver_full=$(rpm --query --queryformat '%{VERSION}' "${kernel_rpm}")
+            kver_full=$(rpm --query --queryformat '%{VERSION}-%{RELEASE}' "${kernel_rpm}")
 
             #
             # Extract kernel config
             #
 
-            config_path=${output_dir}/config-${arch}-${variant}-${state}
             rpm2cpio "${kernel_rpm}" \
                 | cpio --quiet --extract --to-stdout ./boot/config >"${config_path}"
             [[ -s "${config_path}" ]] || bail "Failed to extract config for ${debug_id}"