Nested Virtualization: enablement

diff -r 092d43f1ba2a -r cffdbc93e781 xen/arch/x86/hvm/hvm.c
@@ -828,10 +828,16 @@ int hvm_vcpu_initialise(struct vcpu *v)
     if ( (rc = hvm_funcs.vcpu_initialise(v)) != 0 )
         goto fail2;
 
+    rc = nestedhvm_vcpu_initialise(v);
+    if ( rc < 0 ) {
+        printk("%s: nestedhvm_vcpu_initialise returned %i\n", __func__, rc);
+        goto fail3;
+    }
+
     /* Create ioreq event channel. */
     rc = alloc_unbound_xen_event_channel(v, 0);
     if ( rc < 0 )
-        goto fail3;
+        goto fail4;
 
     /* Register ioreq event channel. */
     v->arch.hvm_vcpu.xen_port = rc;

@@ -845,7 +851,7 @@ int hvm_vcpu_initialise(struct vcpu *v)
 
     rc = hvm_vcpu_cacheattr_init(v);
     if ( rc != 0 )
-        goto fail3;
+        goto fail4;
 
     tasklet_init(&v->arch.hvm_vcpu.assert_evtchn_irq_tasklet,
                  (void(*)(unsigned long))hvm_assert_evtchn_irq,

@@ -870,6 +876,8 @@ int hvm_vcpu_initialise(struct vcpu *v)
 
     return 0;
 
+ fail4:
+    nestedhvm_vcpu_destroy(v);
  fail3:
     hvm_funcs.vcpu_destroy(v);
  fail2:

@@ -880,6 +888,12 @@ int hvm_vcpu_initialise(struct vcpu *v)
 
 void hvm_vcpu_destroy(struct vcpu *v)
 {
+    int rc;
+
+    rc = nestedhvm_vcpu_destroy(v);
+    if (rc < 0)
+	printk("%s: nestedhvm_vcpu_destroy() failed with %i\n", __func__, rc);
+
     tasklet_kill(&v->arch.hvm_vcpu.assert_evtchn_irq_tasklet);
     hvm_vcpu_cacheattr_destroy(v);
     vlapic_destroy(v);

@@ -3021,6 +3035,16 @@ long do_hvm_op(unsigned long op, XEN_GUE
                     rc = -EINVAL;
 
                 break;
+            case HVM_PARAM_NESTEDHVM:
+                if ( a.value > 1 )
+                    rc = -EINVAL;
+                if ( !is_hvm_domain(d) )
+                    rc = -EINVAL;
+                /* Remove the check below once we have
+                 * shadow-on-shadow.
+                 */
+                if ( !paging_mode_hap(d) && a.value )
+                    rc = -EINVAL;
             }
 
             if ( rc == 0 )