diff --git a/build/meta-qemu/classes/qemu.bbclass b/build/meta-qemu/classes/qemu.bbclass
index 7d267505cb..b9062ffa94 100644
--- a/build/meta-qemu/classes/qemu.bbclass
+++ b/build/meta-qemu/classes/qemu.bbclass
@@ -11,15 +11,30 @@ qemu_do_configure () {
 	# per IB_PLATFORM), but PRESERVE any other arch already built in a prior
 	# run — otherwise meson would drop it. So building arm-softmmu then
 	# aarch64-softmmu (or vice-versa) keeps both qemu-system-* binaries.
-	tlist="${QEMU_TARGET}"
+	#
+	# Fixed order, so the same targets always give the same configure line.
+
+	tlist=""
 	for t in arm-softmmu aarch64-softmmu; do
-		if [ "$t" != "${QEMU_TARGET}" ] && ls build/$t/qemu-system-* >/dev/null 2>&1; then
-			tlist="$tlist,$t"
+		if [ "$t" = "${QEMU_TARGET}" ] || ls build/$t/qemu-system-* >/dev/null 2>&1; then
+			tlist="${tlist:+$tlist,}$t"
 		fi
 	done
 
+	# QEMU's configure wipes build/, so re-running it means a full rebuild.
+	# Only run it when the options changed; meson/ninja handle the rest.
+
+	args="--target-list=$tlist ${QEMU_OPTS}"
+	stamp=build/.ib-configure-args
+
+	if [ -f $stamp ] && [ "$(cat $stamp)" = "$args" ]; then
+		echo "QEMU already configured (target-list=$tlist), skipping configure"
+		return
+	fi
+
 	echo "Configuring QEMU (target-list=$tlist)..."
-	./configure --target-list=$tlist ${QEMU_OPTS}
+	./configure $args
+	echo "$args" > $stamp
 
 }