diff --git a/tools/libxc/include/xenctrl.h b/tools/libxc/include/xenctrl.h
index bde8313..eed60db 100644
--- a/tools/libxc/include/xenctrl.h
+++ b/tools/libxc/include/xenctrl.h
@@ -2022,6 +2022,8 @@ int xc_monitor_descriptor_access(xc_interface *xch, domid_t domain_id,
                                  bool enable);
 int xc_monitor_guest_request(xc_interface *xch, domid_t domain_id,
                              bool enable, bool sync);
+int xc_monitor_guest_userspace_vmcall(xc_interface *xch, domid_t domain_id,
+                                      bool enable);
 int xc_monitor_debug_exceptions(xc_interface *xch, domid_t domain_id,
                                 bool enable, bool sync);
 int xc_monitor_cpuid(xc_interface *xch, domid_t domain_id, bool enable);
diff --git a/tools/libxc/xc_monitor.c b/tools/libxc/xc_monitor.c
index b44ce93..63c6320 100644
--- a/tools/libxc/xc_monitor.c
+++ b/tools/libxc/xc_monitor.c
@@ -161,6 +161,20 @@ int xc_monitor_guest_request(xc_interface *xch, domid_t domain_id, bool enable,
     return do_domctl(xch, &domctl);
 }
 
+int xc_allow_guest_userspace_vmcall(xc_interface *xch, domid_t domain_id, bool enable)
+{
+    DECLARE_DOMCTL;
+
+    domctl.cmd = XEN_DOMCTL_monitor_op;
+    domctl.domain = domain_id;
+    domctl.u.monitor_op.op = enable ? XEN_DOMCTL_MONITOR_OP_ENABLE
+                                    : XEN_DOMCTL_MONITOR_OP_DISABLE;
+    domctl.u.monitor_op.event = XEN_DOMCTL_MONITOR_EVENT_GUEST_USERSPACE_VMCALL;
+
+    return do_domctl(xch, &domctl);
+}
+
+
 int xc_monitor_emulate_each_rep(xc_interface *xch, domid_t domain_id,
                                 bool enable)
 {
diff --git a/xen/arch/x86/hvm/hypercall.c b/xen/arch/x86/hvm/hypercall.c
index e7238ce..c7fab4b 100644
--- a/xen/arch/x86/hvm/hypercall.c
+++ b/xen/arch/x86/hvm/hypercall.c
@@ -152,9 +152,17 @@ int hvm_hypercall(struct cpu_user_regs *regs)
     {
     case 8:
         eax = regs->rax;
+        if ( currd->monitor.guest_request_userspace_vmcall &&
+             eax == __HYPERVISOR_hvm_op &&
+             regs->rdi == HVMOP_guest_request_vm_event )
+            break;
         /* Fallthrough to permission check. */
     case 4:
     case 2:
+        if ( mode != 8 && currd->monitor.guest_request_userspace_vmcall &&
+             eax == __HYPERVISOR_hvm_op &&
+             regs->ebx == HVMOP_guest_request_vm_event )
+            break;
         if ( unlikely(hvm_get_cpl(curr)) )
         {
     default:
diff --git a/xen/common/monitor.c b/xen/common/monitor.c
index 451f42f..4011dc3 100644
--- a/xen/common/monitor.c
+++ b/xen/common/monitor.c
@@ -78,6 +78,19 @@ int monitor_domctl(struct domain *d, struct xen_domctl_monitor_op *mop)
         domain_unpause(d);
         break;
     }
+    case XEN_DOMCTL_MONITOR_EVENT_GUEST_USERSPACE_VMCALL:
+    {
+        bool_t old_status = d->monitor.guest_request_enabled;
+
+        if ( unlikely(old_status == requested_status) )
+            return -EEXIST;
+
+        domain_pause(d);
+        d->monitor.guest_request_sync = mop->u.guest_request.sync;
+        d->monitor.guest_request_userspace_vmcall = requested_status;
+        domain_unpause(d);
+        break;
+    }
 
     default:
         /* Give arch-side the chance to handle this event */
diff --git a/xen/include/public/domctl.h b/xen/include/public/domctl.h
index ff39762..e782517 100644
--- a/xen/include/public/domctl.h
+++ b/xen/include/public/domctl.h
@@ -1073,16 +1073,17 @@ DEFINE_XEN_GUEST_HANDLE(xen_domctl_psr_cmt_op_t);
 #define XEN_DOMCTL_MONITOR_OP_GET_CAPABILITIES  2
 #define XEN_DOMCTL_MONITOR_OP_EMULATE_EACH_REP  3
 
-#define XEN_DOMCTL_MONITOR_EVENT_WRITE_CTRLREG         0
-#define XEN_DOMCTL_MONITOR_EVENT_MOV_TO_MSR            1
-#define XEN_DOMCTL_MONITOR_EVENT_SINGLESTEP            2
-#define XEN_DOMCTL_MONITOR_EVENT_SOFTWARE_BREAKPOINT   3
-#define XEN_DOMCTL_MONITOR_EVENT_GUEST_REQUEST         4
-#define XEN_DOMCTL_MONITOR_EVENT_DEBUG_EXCEPTION       5
-#define XEN_DOMCTL_MONITOR_EVENT_CPUID                 6
-#define XEN_DOMCTL_MONITOR_EVENT_PRIVILEGED_CALL       7
-#define XEN_DOMCTL_MONITOR_EVENT_INTERRUPT             8
-#define XEN_DOMCTL_MONITOR_EVENT_DESC_ACCESS           9
+#define XEN_DOMCTL_MONITOR_EVENT_WRITE_CTRLREG          0
+#define XEN_DOMCTL_MONITOR_EVENT_MOV_TO_MSR             1
+#define XEN_DOMCTL_MONITOR_EVENT_SINGLESTEP             2
+#define XEN_DOMCTL_MONITOR_EVENT_SOFTWARE_BREAKPOINT    3
+#define XEN_DOMCTL_MONITOR_EVENT_GUEST_REQUEST          4
+#define XEN_DOMCTL_MONITOR_EVENT_DEBUG_EXCEPTION        5
+#define XEN_DOMCTL_MONITOR_EVENT_CPUID                  6
+#define XEN_DOMCTL_MONITOR_EVENT_PRIVILEGED_CALL        7
+#define XEN_DOMCTL_MONITOR_EVENT_INTERRUPT              8
+#define XEN_DOMCTL_MONITOR_EVENT_DESC_ACCESS            9
+#define XEN_DOMCTL_MONITOR_EVENT_GUEST_USERSPACE_VMCALL 10
 
 struct xen_domctl_monitor_op {
     uint32_t op; /* XEN_DOMCTL_MONITOR_OP_* */
diff --git a/xen/include/xen/sched.h b/xen/include/xen/sched.h
index 6673b27..11137b0 100644
--- a/xen/include/xen/sched.h
+++ b/xen/include/xen/sched.h
@@ -480,8 +480,9 @@ struct domain
 
     /* Common monitor options */
     struct {
-        unsigned int guest_request_enabled       : 1;
-        unsigned int guest_request_sync          : 1;
+        unsigned int guest_request_enabled          : 1;
+        unsigned int guest_request_sync             : 1;
+        unsigned int guest_request_userspace_vmcall : 1;
     } monitor;
 };
 
