--- zzzz-none-000/linux-3.10.107/tools/virtio/asm/barrier.h	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/tools/virtio/asm/barrier.h	2021-02-04 17:41:59.000000000 +0000
@@ -3,6 +3,8 @@
 #define mb() __sync_synchronize()
 
 #define smp_mb()	mb()
+# define dma_rmb()	barrier()
+# define dma_wmb()	barrier()
 # define smp_rmb()	barrier()
 # define smp_wmb()	barrier()
 /* Weak barriers should be used. If not - it's a bug */