run kvm instance with the right number of cpus according to given parallel build...

diff --git a/build b/build
index 7e90b3f..69b7a6f 100755 (executable)
--- a/build
+++ b/build
@@ -993,6 +993,9 @@ if [ "$VM_TYPE" = 'kvm' -a -z "$RUNNING_IN_VM" ]; then
        cleanup_and_exit 3
     fi
     qemu_bin="$kvm_bin"
+    if [ -n "$BUILD_JOBS" ]; then
+        qemu_bin="$kvm_bin -smp $BUILD_JOBS"
+    fi
     if [ -n "$VM_KERNEL" ]; then
        qemu_kernel="$VM_KERNEL"
     fi