libvhost-user: fix SLAVE_SEND_FD handling

It doesn't look like this could possibly work properly since
VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD is defined to 10, but the
dev->protocol_features has a bitmap. I suppose the peer this
was tested with also supported VHOST_USER_PROTOCOL_F_LOG_SHMFD,
in which case the test would always be false, but nevertheless
the code seems wrong.

Use has_feature() to fix this.

Fixes: d84599f56c82 ("libvhost-user: support host notifier")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Message-Id: <20190903200422.11693-1-johannes@sipsolutions.net>
Reviewed-by: Tiwei Bie <tiwei.bie@intel.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
(cherry picked from commit 8726b70b449896f1211f869ec4f608904f027207)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>

diff --git a/contrib/libvhost-user/libvhost-user.c b/contrib/libvhost-user/libvhost-user.c
index 4b36e35a82f8c99b84ac1e71deec9a2d74120744..cb5f5770e4c6ba73df06ea8c7d72794bde1ca796 100644 (file)
--- a/contrib/libvhost-user/libvhost-user.c
+++ b/contrib/libvhost-user/libvhost-user.c
@@ -1097,7 +1097,8 @@ bool vu_set_queue_host_notifier(VuDev *dev, VuVirtq *vq, int fd,
 
     vmsg.fd_num = fd_num;
 
-    if ((dev->protocol_features & VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD) == 0) {
+    if (!has_feature(dev->protocol_features,
+                     VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD)) {
         return false;
     }