xsm: correct AVC lookups for two sysctls

The current code was incorrectly using SECCLASS_XEN instead of
SECCLASS_XEN2, resulting in the wrong permission being checked.

GET_CPU_LEVELLING_CAPS was checking MTRR_DEL
GET_CPU_FEATURESET was checking MTRR_READ

The default XSM policy only allowed these permissions to dom0, so this
didn't result in a security issue there.

Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>

xen/xsm/flask/hooks.c

@@ -814,10 +814,12 @@ static int flask_sysctl(int cmd)
         return domain_has_xen(current->domain, XEN__TMEM_CONTROL);
 
     case XEN_SYSCTL_get_cpu_levelling_caps:
-        return domain_has_xen(current->domain, XEN2__GET_CPU_LEVELLING_CAPS);
+        return avc_current_has_perm(SECINITSID_XEN, SECCLASS_XEN2,
+                                    XEN2__GET_CPU_LEVELLING_CAPS);
 
     case XEN_SYSCTL_get_cpu_featureset:
-        return domain_has_xen(current->domain, XEN2__GET_CPU_FEATURESET);
+        return avc_current_has_perm(SECINITSID_XEN, SECCLASS_XEN2,
+                                    XEN2__GET_CPU_FEATURESET);
 
     case XEN_SYSCTL_livepatch_op:
         return avc_current_has_perm(SECINITSID_XEN, SECCLASS_XEN2,