x86: remove IS_PRIV access check bypasses

Several domctl functions dealing with rangesets contain a short-circuit
bypass if the domain is privileged. Since the construction of domain 0
permits access to all I/O ranges, the call to irq_access_permitted will
normally return true even without the IS_PRIV check, and the presence of
the IS_PRIV check prevents the creation of a privileged domain without
access to specific devices or IO memory ranges.

Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>

xen/arch/x86/domctl.c

@@ -645,8 +645,7 @@ long arch_do_domctl(
             break;
 
         ret = -EPERM;
-        if ( !IS_PRIV(current->domain) &&
-             !iomem_access_permitted(current->domain, mfn, mfn + nr_mfns - 1) )
+        if ( !iomem_access_permitted(current->domain, mfn, mfn + nr_mfns - 1) )
             break;
 
         ret = xsm_iomem_mapping(XSM_HOOK, d, mfn, mfn + nr_mfns - 1, add);
@@ -723,8 +722,7 @@ long arch_do_domctl(
         }
 
         ret = -EPERM;
-        if ( !IS_PRIV(current->domain) &&
-             !ioports_access_permitted(current->domain, fmp, fmp + np - 1) )
+        if ( !ioports_access_permitted(current->domain, fmp, fmp + np - 1) )
             break;
 
         ret = xsm_ioport_mapping(XSM_HOOK, d, fmp, fmp + np - 1, add);

xen/arch/x86/irq.c

@@ -1891,8 +1891,7 @@ int map_domain_pirq(
 
     ASSERT(spin_is_locked(&d->event_lock));
 
-    if ( !IS_PRIV(current->domain) &&
-         !irq_access_permitted(current->domain, irq))
+    if ( !irq_access_permitted(current->domain, irq))
         return -EPERM;
 
     if ( pirq < 0 || pirq >= d->nr_pirqs || irq < 0 || irq >= nr_irqs )