xen/xsm: wrap around xsm_sysctl with CONFIG_SYSCTL

As function xsm_sysctl() is solely invoked in sysctl.c, we need to
wrap around it with CONFIG_SYSCTL

Signed-off-by: Penny Zheng <Penny.Zheng@amd.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Acked-by: Daniel P. Smith <dpsmith@apertussolutions.com>

xen/include/xsm/xsm.h

@@ -261,7 +261,11 @@ static inline int xsm_domctl(xsm_default_t def, struct domain *d,
 
 static inline int xsm_sysctl(xsm_default_t def, int cmd)
 {
+#ifdef CONFIG_SYSCTL
     return alternative_call(xsm_ops.sysctl, cmd);
+#else
+    return -EOPNOTSUPP;
+#endif
 }
 
 static inline int xsm_readconsole(xsm_default_t def, uint32_t clear)

xen/xsm/dummy.c

@@ -22,7 +22,9 @@ static const struct xsm_ops __initconst_cf_clobber dummy_ops = {
     .sysctl_scheduler_op           = xsm_sysctl_scheduler_op,
     .set_target                    = xsm_set_target,
     .domctl                        = xsm_domctl,
+#ifdef CONFIG_SYSCTL
     .sysctl                        = xsm_sysctl,
+#endif
     .readconsole                   = xsm_readconsole,
 
     .evtchn_unbound                = xsm_evtchn_unbound,

xen/xsm/flask/hooks.c

@@ -856,6 +856,7 @@ static int cf_check flask_domctl(struct domain *d, unsigned int cmd,
     }
 }
 
+#ifdef CONFIG_SYSCTL
 static int cf_check flask_sysctl(int cmd)
 {
     switch ( cmd )
@@ -933,6 +934,7 @@ static int cf_check flask_sysctl(int cmd)
         return avc_unknown_permission("sysctl", cmd);
     }
 }
+#endif /* CONFIG_SYSCTL */
 
 static int cf_check flask_readconsole(uint32_t clear)
 {
@@ -1884,7 +1886,9 @@ static const struct xsm_ops __initconst_cf_clobber flask_ops = {
     .sysctl_scheduler_op = flask_sysctl_scheduler_op,
     .set_target = flask_set_target,
     .domctl = flask_domctl,
+#ifdef CONFIG_SYSCTL
     .sysctl = flask_sysctl,
+#endif
     .readconsole = flask_readconsole,
 
     .evtchn_unbound = flask_evtchn_unbound,