xen: Introduce CONFIG_SELF_TESTS

... and move x86's stub_selftest() under this new option.

There is value in having these tests included in release builds too.

It will shortly be used to gate the bitops unit tests on all architectures.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Release-Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>

xen/Kconfig.debug

@@ -29,6 +29,12 @@ config FRAME_POINTER
 	  maybe slower, but it gives very useful debugging information
 	  in case of any Xen bugs.
 
+config SELF_TESTS
+	bool "Extra self-testing"
+	default DEBUG
+	help
+	  Enable extra unit and functional testing.
+
 config COVERAGE
 	bool "Code coverage support"
 	depends on !LIVEPATCH

xen/arch/x86/extable.c

@@ -144,7 +144,7 @@ search_exception_table(const struct cpu_user_regs *regs, unsigned long *stub_ra)
     return 0;
 }
 
-#ifdef CONFIG_DEBUG
+#ifdef CONFIG_SELF_TESTS
 #include <asm/setup.h>
 #include <asm/traps.h>
 
@@ -214,7 +214,7 @@ int __init cf_check stub_selftest(void)
     return 0;
 }
 __initcall(stub_selftest);
-#endif
+#endif /* CONFIG_SELF_TESTS */
 
 unsigned long asmlinkage search_pre_exception_table(struct cpu_user_regs *regs)
 {

xen/arch/x86/setup.c

@@ -742,7 +742,7 @@ static void noreturn init_done(void)
     system_state = SYS_STATE_active;
 
     /* Re-run stub recovery self-tests with CET-SS active. */
-    if ( IS_ENABLED(CONFIG_DEBUG) && cpu_has_xen_shstk )
+    if ( IS_ENABLED(CONFIG_SELF_TESTS) && cpu_has_xen_shstk )
         stub_selftest();
 
     domain_unpause_by_systemcontroller(dom0);