devtool: move ensure_kvm into devtool

This one was only used in devtool, so
move it there.

No functional change.

Signed-off-by: Egor Lazarchuk <yegorlz@amazon.co.uk>

Author: ShadowCurse

tools/devtool

@@ -583,6 +583,43 @@ ensure_ci_artifacts() {
     fi
 }
 
+# Attempt to load the appropriate KVM module for the current platform.
+# Returns 0 on success, non-zero on failure.
+#
+load_kvm() {
+    local arch
+    arch=$(uname -m)
+
+    case "$arch" in
+        x86_64|i*86)
+            if grep -q "vmx" /proc/cpuinfo; then
+                modprobe kvm_intel || return 1
+            elif grep -q "svm" /proc/cpuinfo; then
+                modprobe kvm_amd avic=1 || return 1
+            else
+                return 1
+            fi
+            ;;
+        aarch64|arm*)
+            modprobe kvm || return 1
+            ;;
+        *)
+            return 1
+            ;;
+    esac
+
+    # Check /dev/kvm now exists
+    [[ -c /dev/kvm ]]
+}
+
+# Check if /dev/kvm exists. Attempt to load the module if it doesn't.
+# Exit if KVM is unavailable. Upon returning from this call, the caller
+# can be certain /dev/kvm is available.
+#
+ensure_kvm() {
+    [[ -c /dev/kvm ]] || load_kvm || die "/dev/kvm not found. Aborting."
+}
+
 apply_linux_61_tweaks() {
     KV=$(uname -r)
     if [[ $KV != 6.1.* ]] || [ $(uname -m) != x86_64 ]; then

tools/functions

@@ -125,15 +125,3 @@ function validate_version {
         die "Invalid version number: $version. Version should not contain \`wip\` or \`dirty\`."
     fi
 }
-
-#########################
-# Firecracker functions #
-#########################
-
-# Check if /dev/kvm exists. Exit if it doesn't.
-# Upon returning from this call, the caller can be certain /dev/kvm is
-# available.
-#
-ensure_kvm() {
-    [[ -c /dev/kvm ]] || die "/dev/kvm not found. Aborting."
-}