diff --git a/xen/arch/x86/domctl.c b/xen/arch/x86/domctl.c
index 2ed651da02..e8f53633be 100644
--- a/xen/arch/x86/domctl.c
+++ b/xen/arch/x86/domctl.c
@@ -1075,45 +1075,48 @@ long arch_do_domctl(
              ((v = d->vcpu[evc->vcpu]) == NULL) )
             goto vcpuextstate_out;
 
+        ret = -EINVAL;
+        if ( v == current ) /* no vcpu_pause() */
+            goto vcpuextstate_out;
+
         if ( domctl->cmd == XEN_DOMCTL_getvcpuextstate )
         {
-            unsigned int size = PV_XSAVE_SIZE(v->arch.xcr0_accum);
+            unsigned int size;
 
-            if ( !evc->size && !evc->xfeature_mask )
+            ret = 0;
+            vcpu_pause(v);
+
+            size = PV_XSAVE_SIZE(v->arch.xcr0_accum);
+            if ( (!evc->size && !evc->xfeature_mask) ||
+                 guest_handle_is_null(evc->buffer) )
             {
                 evc->xfeature_mask = xfeature_mask;
                 evc->size = size;
-                ret = 0;
+                vcpu_unpause(v);
                 goto vcpuextstate_out;
             }
+
             if ( evc->size != size || evc->xfeature_mask != xfeature_mask )
-            {
                 ret = -EINVAL;
-                goto vcpuextstate_out;
-            }
-            if ( copy_to_guest_offset(domctl->u.vcpuextstate.buffer,
-                                      offset, (void *)&v->arch.xcr0,
-                                      sizeof(v->arch.xcr0)) )
-            {
+
+            if ( !ret && copy_to_guest_offset(evc->buffer, offset,
+                                              (void *)&v->arch.xcr0,
+                                              sizeof(v->arch.xcr0)) )
                 ret = -EFAULT;
-                goto vcpuextstate_out;
-            }
+
             offset += sizeof(v->arch.xcr0);
-            if ( copy_to_guest_offset(domctl->u.vcpuextstate.buffer,
-                                      offset, (void *)&v->arch.xcr0_accum,
-                                      sizeof(v->arch.xcr0_accum)) )
-            {
+            if ( !ret && copy_to_guest_offset(evc->buffer, offset,
+                                              (void *)&v->arch.xcr0_accum,
+                                              sizeof(v->arch.xcr0_accum)) )
                 ret = -EFAULT;
-                goto vcpuextstate_out;
-            }
+
             offset += sizeof(v->arch.xcr0_accum);
-            if ( copy_to_guest_offset(domctl->u.vcpuextstate.buffer,
-                                      offset, (void *)v->arch.xsave_area,
-                                      size - 2 * sizeof(uint64_t)) )
-            {
+            if ( !ret && copy_to_guest_offset(evc->buffer, offset,
+                                              (void *)v->arch.xsave_area,
+                                              size - 2 * sizeof(uint64_t)) )
                 ret = -EFAULT;
-                goto vcpuextstate_out;
-            }
+
+            vcpu_unpause(v);
         }
         else
         {
@@ -1162,12 +1165,14 @@ long arch_do_domctl(
 
             if ( evc->size <= PV_XSAVE_SIZE(_xcr0_accum) )
             {
+                vcpu_pause(v);
                 v->arch.xcr0 = _xcr0;
                 v->arch.xcr0_accum = _xcr0_accum;
                 if ( _xcr0_accum & XSTATE_NONLAZY )
                     v->arch.nonlazy_xstate_used = 1;
                 memcpy(v->arch.xsave_area, _xsave_area,
                        evc->size - 2 * sizeof(uint64_t));
+                vcpu_unpause(v);
             }
             else
                 ret = -EINVAL;
@@ -1175,8 +1180,6 @@ long arch_do_domctl(
             xfree(receive_buf);
         }
 
-        ret = 0;
-
     vcpuextstate_out:
         if ( domctl->cmd == XEN_DOMCTL_getvcpuextstate )
             copyback = 1;