+#### Xen support (optional) ####
+
+AC_ARG_ENABLE([xen],
+ AS_HELP_STRING([--disable-xen],[Disable optional Xen paravirtualized driver]))
+
+XEN_CFLAGS=
+XEN_LIBS=
+
+AS_IF([test "x$enable_xen" != "xno"],
+ [
+ HAVE_XEN=1
+ AC_CHECK_HEADER(xenctrl.h, [], [HAVE_XEN=0])
+ AC_CHECK_HEADER(xs.h, [], [HAVE_XEN=0])
+ AC_CHECK_LIB(xenctrl, xc_interface_open, [XEN_LIBS="$XEN_LIBS -lxenctrl"], [HAVE_XEN=0])
+ AC_CHECK_LIB(xenstore, xs_domain_open, [XEN_LIBS="$XEN_LIBS -lxenstore"], [HAVE_XEN=0])
+ ],
+ HAVE_XEN=0)
+
+AS_IF([test "x$enable_xen" = "xyes" && test "x$HAVE_XEN" = "x0"],
+ [AC_MSG_ERROR([*** Xen development headers or libraries not found])])
+
+AC_SUBST(XEN_CFLAGS)
+AC_SUBST(XEN_LIBS)
+AM_CONDITIONAL([HAVE_XEN], [test "x$HAVE_XEN" = x1])
+
+#### gcov support (optional) #####
+
+AC_ARG_ENABLE([gcov],
+ AS_HELP_STRING([--enable-gcov],[Enable optional gcov coverage analysis]))
+
+GCOV_CFLAGS=
+GCOV_LIBS=" -lgcov"
+
+AS_IF([test "x$enable_gcov" = "xyes"],
+ [
+ HAVE_GCOV=1
+ GCOV_CFLAGS="$GCOV_CFLAGS -fprofile-arcs -ftest-coverage"
+ GCOV_LIBS="$GCOV_LIBS -fprofile-arcs"
+ ],
+ HAVE_GCOV=0)
+
+AC_SUBST(GCOV_CFLAGS)
+AC_SUBST(GCOV_LIBS)
+AM_CONDITIONAL([HAVE_GCOV], [test "x$HAVE_GCOV" = x1])