diff --git a/tools/flask/policy/modules/guest_features.te b/tools/flask/policy/modules/guest_features.te
index 9ac9780ded..d00769e1d2 100644
--- a/tools/flask/policy/modules/guest_features.te
+++ b/tools/flask/policy/modules/guest_features.te
@@ -5,6 +5,12 @@ allow domain_type xen_t:xen tmem_op;
 # pmu_ctrl is for)
 allow domain_type xen_t:xen2 pmu_use;
 
+# Allow all domains:
+# to register single-sender (unicast) rings to partner with any domain; and
+# to register any-sender (wildcard) rings that can be sent to by any domain.
+allow domain_type xen_t:argo { register_any_source };
+allow domain_type domain_type:argo { register_single_source };
+
 # Allow guest console output to the serial console.  This is used by PV Linux
 # and stub domains for early boot output, so don't audit even when we deny it.
 # Without XSM, this is enabled only if the Xen was compiled in debug mode.
diff --git a/xen/common/argo.c b/xen/common/argo.c
index dce90ee302..1a9a0e8013 100644
--- a/xen/common/argo.c
+++ b/xen/common/argo.c
@@ -26,6 +26,7 @@
 #include <xen/nospec.h>
 #include <xen/sched.h>
 #include <xen/time.h>
+#include <xsm/xsm.h>
 
 #include <public/argo.h>
 
@@ -1652,8 +1653,10 @@ register_ring(struct domain *currd,
 
     if ( reg.partner_id == XEN_ARGO_DOMID_ANY )
     {
-        if ( !opt_argo_mac_permissive )
-            return -EPERM;
+        ret = opt_argo_mac_permissive ? xsm_argo_register_any_source(currd) :
+                                        -EPERM;
+        if ( ret )
+            return ret;
     }
     else
     {
@@ -1664,6 +1667,10 @@ register_ring(struct domain *currd,
             return -ESRCH;
         }
 
+        ret = xsm_argo_register_single_source(currd, dst_d);
+        if ( ret )
+            goto out;
+
         send_info = xzalloc(struct argo_send_info);
         if ( !send_info )
         {
diff --git a/xen/include/xsm/dummy.h b/xen/include/xsm/dummy.h
index a29d1efe9b..9abfd69762 100644
--- a/xen/include/xsm/dummy.h
+++ b/xen/include/xsm/dummy.h
@@ -720,6 +720,20 @@ static XSM_INLINE int xsm_dm_op(XSM_DEFAULT_ARG struct domain *d)
 
 #endif /* CONFIG_X86 */
 
+#ifdef CONFIG_ARGO
+static XSM_INLINE int xsm_argo_register_single_source(const struct domain *d,
+                                                      const struct domain *t)
+{
+    return 0;
+}
+
+static XSM_INLINE int xsm_argo_register_any_source(const struct domain *d)
+{
+    return 0;
+}
+
+#endif /* CONFIG_ARGO */
+
 #include <public/version.h>
 static XSM_INLINE int xsm_xen_version (XSM_DEFAULT_ARG uint32_t op)
 {
diff --git a/xen/include/xsm/xsm.h b/xen/include/xsm/xsm.h
index 3b192b5c31..0b40714245 100644
--- a/xen/include/xsm/xsm.h
+++ b/xen/include/xsm/xsm.h
@@ -181,6 +181,11 @@ struct xsm_operations {
 #endif
     int (*xen_version) (uint32_t cmd);
     int (*domain_resource_map) (struct domain *d);
+#ifdef CONFIG_ARGO
+    int (*argo_register_single_source) (const struct domain *d,
+                                        const struct domain *t);
+    int (*argo_register_any_source) (const struct domain *d);
+#endif
 };
 
 #ifdef CONFIG_XSM
@@ -698,6 +703,20 @@ static inline int xsm_domain_resource_map(xsm_default_t def, struct domain *d)
     return xsm_ops->domain_resource_map(d);
 }
 
+#ifdef CONFIG_ARGO
+static inline int xsm_argo_register_single_source(const struct domain *d,
+                                                  const struct domain *t)
+{
+    return xsm_ops->argo_register_single_source(d, t);
+}
+
+static inline int xsm_argo_register_any_source(const struct domain *d)
+{
+    return xsm_ops->argo_register_any_source(d);
+}
+
+#endif /* CONFIG_ARGO */
+
 #endif /* XSM_NO_WRAPPERS */
 
 #ifdef CONFIG_MULTIBOOT
diff --git a/xen/xsm/dummy.c b/xen/xsm/dummy.c
index 5701047c06..ed236b09b3 100644
--- a/xen/xsm/dummy.c
+++ b/xen/xsm/dummy.c
@@ -152,4 +152,8 @@ void __init xsm_fixup_ops (struct xsm_operations *ops)
 #endif
     set_to_dummy_if_null(ops, xen_version);
     set_to_dummy_if_null(ops, domain_resource_map);
+#ifdef CONFIG_ARGO
+    set_to_dummy_if_null(ops, argo_register_single_source);
+    set_to_dummy_if_null(ops, argo_register_any_source);
+#endif
 }
diff --git a/xen/xsm/flask/hooks.c b/xen/xsm/flask/hooks.c
index 96d31aaf08..fcb74871d9 100644
--- a/xen/xsm/flask/hooks.c
+++ b/xen/xsm/flask/hooks.c
@@ -36,13 +36,14 @@
 #include <objsec.h>
 #include <conditional.h>
 
-static u32 domain_sid(struct domain *dom)
+static u32 domain_sid(const struct domain *dom)
 {
     struct domain_security_struct *dsec = dom->ssid;
     return dsec->sid;
 }
 
-static u32 domain_target_sid(struct domain *src, struct domain *dst)
+static u32 domain_target_sid(const struct domain *src,
+                             const struct domain *dst)
 {
     struct domain_security_struct *ssec = src->ssid;
     struct domain_security_struct *dsec = dst->ssid;
@@ -58,7 +59,8 @@ static u32 evtchn_sid(const struct evtchn *chn)
     return chn->ssid.flask_sid;
 }
 
-static int domain_has_perm(struct domain *dom1, struct domain *dom2, 
+static int domain_has_perm(const struct domain *dom1,
+                           const struct domain *dom2,
                            u16 class, u32 perms)
 {
     u32 ssid, tsid;
@@ -1717,6 +1719,21 @@ static int flask_domain_resource_map(struct domain *d)
     return current_has_perm(d, SECCLASS_DOMAIN2, DOMAIN2__RESOURCE_MAP);
 }
 
+#ifdef CONFIG_ARGO
+static int flask_argo_register_single_source(const struct domain *d,
+                                             const struct domain *t)
+{
+    return domain_has_perm(d, t, SECCLASS_ARGO,
+                           ARGO__REGISTER_SINGLE_SOURCE);
+}
+
+static int flask_argo_register_any_source(const struct domain *d)
+{
+    return avc_has_perm(domain_sid(d), SECINITSID_XEN, SECCLASS_ARGO,
+                        ARGO__REGISTER_ANY_SOURCE, NULL);
+}
+#endif
+
 long do_flask_op(XEN_GUEST_HANDLE_PARAM(xsm_op_t) u_flask_op);
 int compat_flask_op(XEN_GUEST_HANDLE_PARAM(xsm_op_t) u_flask_op);
 
@@ -1851,6 +1868,10 @@ static struct xsm_operations flask_ops = {
 #endif
     .xen_version = flask_xen_version,
     .domain_resource_map = flask_domain_resource_map,
+#ifdef CONFIG_ARGO
+    .argo_register_single_source = flask_argo_register_single_source,
+    .argo_register_any_source = flask_argo_register_any_source,
+#endif
 };
 
 void __init flask_init(const void *policy_buffer, size_t policy_size)
diff --git a/xen/xsm/flask/include/avc.h b/xen/xsm/flask/include/avc.h
index 4046516b9c..93386bd7a1 100644
--- a/xen/xsm/flask/include/avc.h
+++ b/xen/xsm/flask/include/avc.h
@@ -40,8 +40,8 @@ struct avc_audit_data {
 #define AVC_AUDIT_DATA_RANGE 3
 #define AVC_AUDIT_DATA_MEMORY 4
 #define AVC_AUDIT_DATA_DTDEV 5
-    struct domain *sdom;
-    struct domain *tdom;
+    const struct domain *sdom;
+    const struct domain *tdom;
     union {
         unsigned long device;
         int irq;
diff --git a/xen/xsm/flask/policy/access_vectors b/xen/xsm/flask/policy/access_vectors
index 6fecfdaa83..fb95c97418 100644
--- a/xen/xsm/flask/policy/access_vectors
+++ b/xen/xsm/flask/policy/access_vectors
@@ -531,3 +531,14 @@ class version
 # Xen build id
     xen_build_id
 }
+
+# Class argo is used to describe the Argo interdomain communication system.
+class argo
+{
+    # Domain requesting registration of a communication ring
+    # to receive messages from a specific other domain.
+    register_single_source
+    # Domain requesting registration of a communication ring
+    # to receive messages from any other domain.
+    register_any_source
+}
diff --git a/xen/xsm/flask/policy/security_classes b/xen/xsm/flask/policy/security_classes
index cde4e1abbe..50ecbabc5c 100644
--- a/xen/xsm/flask/policy/security_classes
+++ b/xen/xsm/flask/policy/security_classes
@@ -19,5 +19,6 @@ class event
 class grant
 class security
 class version
+class argo
 
 # FLASK