On amd64, if building minimal images for bionic, xenial, or extra ppa,

use kvm kernel, otherwise fallback to virtual.

debian/changelog

@@ -1,3 +1,10 @@
+livecd-rootfs (2.514) bionic; urgency=medium
+
+  * On amd64, if building minimal images for bionic, xenial, or extra ppa,
+    use kvm kernel, otherwise fallback to virtual.
+
+ -- Dimitri John Ledkov <xnox@ubuntu.com>  Wed, 21 Mar 2018 11:02:25 +0000
+
 livecd-rootfs (2.513) bionic; urgency=medium
 
   * In the live-server build, prevent casper from mounting any existing

live-build/auto/config

@@ -624,10 +624,10 @@ case $PROJECT in
 			# linux-kvm is available since you control the
 			# archive and can provide this metapackage as
 			# necessary.
-			if [ "$ARCH" != "amd64" ] || ([ -z "$EXTRA_PPAS" ] && [ "$SUITE" != xenial ]); then
-				KERNEL_FLAVOURS=virtual
-			else
+			if [ "$ARCH" = "amd64" ] && ([ -n "$EXTRA_PPAS" ] || [ "$SUITE" = xenial ] || [ "$SUITE" = bionic ]); then
 				KERNEL_FLAVOURS=kvm
+			else
+				KERNEL_FLAVOURS=virtual
 			fi
 		else
 			add_task install minimal standard cloud-image