1 files changed, 6 insertions, 0 deletions

diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
index 98544c5f86e9..0e15f011f9c8 100644
--- a/arch/arm/xen/enlighten.c
+++ b/arch/arm/xen/enlighten.c
@@ -260,6 +260,12 @@ static int __init xen_guest_init(void)
         xen_domain_type = XEN_HVM_DOMAIN;
 
         xen_setup_features();
+
+        if (!xen_feature(XENFEAT_grant_map_identity)) {
+                pr_warn("Please upgrade your Xen.\n"
+                                "If your platform has any non-coherent DMA devices, they won't work properly.\n");
+        }
+
         if (xen_feature(XENFEAT_dom0))
                 xen_start_info->flags |= SIF_INITDOMAIN|SIF_PRIVILEGED;
         else