[PATCH 1/2] x86/mm: tidy XENMEM_{get,set}_pod_target handling

[Jan Beulich <jbeulich@xxxxxxxx>]

Do away with the "pod_target_out_unlock" label. In particular by folding
if()-s, the logic can be expressed with less code (and no goto-s) this
way.

Limit scope of "p2m", constifying it at the same time.

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>

--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -4777,7 +4777,6 @@ long arch_memory_op(unsigned long cmd, X
     {
         xen_pod_target_t target;
         struct domain *d;
-        struct p2m_domain *p2m;
 
         if ( copy_from_guest(&target, arg, 1) )
             return -EFAULT;
@@ -4789,23 +4788,17 @@ long arch_memory_op(unsigned long cmd, X
         if ( !is_hvm_domain(d) )
             rc = -EINVAL;
         else if ( cmd == XENMEM_set_pod_target )
-            rc = xsm_set_pod_target(XSM_PRIV, d);
-        else
-            rc = xsm_get_pod_target(XSM_PRIV, d);
-
-        if ( rc != 0 )
-            goto pod_target_out_unlock;
-
-        if ( cmd == XENMEM_set_pod_target )
         {
-            if ( target.target_pages > d->max_pages )
-            {
+            rc = xsm_set_pod_target(XSM_PRIV, d);
+            if ( rc )
+                ASSERT(rc < 0);
+            else if ( target.target_pages > d->max_pages )
                 rc = -EINVAL;
-                goto pod_target_out_unlock;
-            }
-
-            rc = p2m_pod_set_mem_target(d, target.target_pages);
+            else
+                rc = p2m_pod_set_mem_target(d, target.target_pages);
         }
+        else
+            rc = xsm_get_pod_target(XSM_PRIV, d);
 
         if ( rc == -ERESTART )
         {
@@ -4814,19 +4807,16 @@ long arch_memory_op(unsigned long cmd, X
         }
         else if ( rc >= 0 )
         {
-            p2m = p2m_get_hostp2m(d);
+            const struct p2m_domain *p2m = p2m_get_hostp2m(d);
+
             target.tot_pages       = domain_tot_pages(d);
             target.pod_cache_pages = p2m->pod.count;
             target.pod_entries     = p2m->pod.entry_count;
 
             if ( __copy_to_guest(arg, &target, 1) )
-            {
-                rc= -EFAULT;
-                goto pod_target_out_unlock;
-            }
+                rc = -EFAULT;
         }
 
-    pod_target_out_unlock:
         rcu_unlock_domain(d);
         return rc;
     }