X-Git-Url: https://gerrit.fd.io/r/gitweb?a=blobdiff_plain;f=src%2Fvnet%2Fdevices%2Ftap%2Ftap.c;h=a1d5981086c8a79b5b730dee6ecdfbd9748ada34;hb=39807d02c9a26d99f96a9669c49ba017bedfe510;hp=bc790adae758ab967a56c6906619e5668ddaee9e;hpb=0ba86cb1bdcc273ebc3d5a92f765639a64894a7a;p=vpp.git

diff --git a/src/vnet/devices/tap/tap.c b/src/vnet/devices/tap/tap.c
index bc790adae75..a1d5981086c 100644
--- a/src/vnet/devices/tap/tap.c
+++ b/src/vnet/devices/tap/tap.c
@@ -94,6 +94,7 @@ tap_create_if (vlib_main_t * vm, tap_create_if_args_t * args)
   struct vhost_memory *vhost_mem = 0;
   virtio_if_t *vif = 0;
   clib_error_t *err = 0;
+  unsigned int tap_features;
   int fd = -1;
   char *host_if_name = 0;
 
@@ -173,6 +174,14 @@ tap_create_if (vlib_main_t * vm, tap_create_if_args_t * args)
       goto error;
     }
 
+  _IOCTL (vif->tap_fd, TUNGETFEATURES, &tap_features);
+  if ((tap_features & IFF_VNET_HDR) == 0)
+    {
+      args->rv = VNET_API_ERROR_SYSCALL_ERROR_2;
+      args->error = clib_error_return (0, "vhost-net backend not available");
+      goto error;
+    }
+
   ifr.ifr_flags = IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE | IFF_VNET_HDR;
   _IOCTL (vif->tap_fd, TUNSETIFF, (void *) &ifr);
   vif->ifindex = if_nametoindex (ifr.ifr_ifrn.ifrn_name);