[PULL v2 29/30] vhost-user: only set slave channel for first vq

["Michael S. Tsirkin" <mst@redhat.com>]

From: Adrian Moreno <amorenoz@redhat.com>

When multiqueue is enabled, a vhost_dev is created for each queue
pair. However, only one slave channel is needed.

Fixes: 4bbeeba023f2 (vhost-user: add slave-req-fd support)
Cc: marcandre.lureau@redhat.com
Signed-off-by: Adrian Moreno <amorenoz@redhat.com>
Message-Id: <20200121214553.28459-1-amorenoz@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 hw/virtio/vhost-user.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
index 2e81f5514f..35baf4f347 100644
--- a/hw/virtio/vhost-user.c
+++ b/hw/virtio/vhost-user.c
@@ -1458,9 +1458,11 @@ static int vhost_user_backend_init(struct vhost_dev *dev, void *opaque)
                    "VHOST_USER_PROTOCOL_F_LOG_SHMFD feature.");
     }
 
-    err = vhost_setup_slave_channel(dev);
-    if (err < 0) {
-        return err;
+    if (dev->vq_index == 0) {
+        err = vhost_setup_slave_channel(dev);
+        if (err < 0) {
+            return err;
+        }
     }
 
     u->postcopy_notifier.notify = vhost_user_postcopy_notifier;
-- 
MST