From: Damjan Marion <damarion@cisco.com>
Date: Tue, 12 Jan 2016 17:34:24 +0000 (+0100)
Subject: Avoid crash in vhost-user driver when running multithreaded
X-Git-Tag: v16.06-rc1~406^2
X-Git-Url: https://gerrit.fd.io/r/gitweb?a=commitdiff_plain;h=920ecc2e1ff2f1bdbd3698243cd1804b4bc2e269;p=vpp.git

Avoid crash in vhost-user driver when running multithreaded

Change-Id: Ib54575453fd26ba1a7256e9d583c8f8532613ebc
Signed-off-by: Carsten Koester <ckoester@cisco.com>
Signed-off-by: Damjan Marion <damarion@cisco.com>
---

diff --git a/vnet/vnet/devices/virtio/vhost-user.c b/vnet/vnet/devices/virtio/vhost-user.c
index 20a4c021c6a..8dca33b82af 100644
--- a/vnet/vnet/devices/virtio/vhost-user.c
+++ b/vnet/vnet/devices/virtio/vhost-user.c
@@ -771,6 +771,9 @@ static u32 vhost_user_if_input ( vlib_main_t * vm,
   if (PREDICT_FALSE(!txvq->desc))
     return 0;
 
+  if (PREDICT_FALSE(!txvq->avail))
+    return 0;
+
   /* do we have pending intterupts ? */
   if ((txvq->n_since_last_int) && (txvq->int_deadline < now))
     vhost_user_send_call(vm, txvq);
@@ -1037,6 +1040,9 @@ vhost_user_intfc_tx (vlib_main_t * vm,
   if (PREDICT_FALSE(!rxvq->desc))
      goto done2;
 
+  if (PREDICT_FALSE(!rxvq->avail))
+    goto done2;
+
   if (PREDICT_FALSE(vui->lockp != 0))
     {
       while (__sync_lock_test_and_set (vui->lockp, 1))