[PATCH 41/55] vhost-user: save features if the char dev is closed

[Michael Roth <mdroth@linux.vnet.ibm.com>]

From: Adrian Moreno <amorenoz@redhat.com>

That way the state can be correctly restored when the device is opened
again. This might happen if the backend is restarted.

Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1738768
Reported-by: Pei Zhang <pezhang@redhat.com>
Fixes: 6ab79a20af3a ("do not call vhost_net_cleanup() on running net from char user event")
Cc: ddstreet@canonical.com
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: qemu-stable@nongnu.org
Signed-off-by: Adrian Moreno <amorenoz@redhat.com>
Message-Id: <20190924162044.11414-1-amorenoz@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
(cherry picked from commit c6beefd674fff8d41b90365dfccad32e53a5abcb)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
---
 net/vhost-user.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/net/vhost-user.c b/net/vhost-user.c
index 51921de443..014199d600 100644
--- a/net/vhost-user.c
+++ b/net/vhost-user.c
@@ -235,6 +235,10 @@ static void chr_closed_bh(void *opaque)
 
     s = DO_UPCAST(NetVhostUserState, nc, ncs[0]);
 
+    if (s->vhost_net) {
+        s->acked_features = vhost_net_get_acked_features(s->vhost_net);
+    }
+
     qmp_set_link(name, false, &err);
 
     qemu_chr_fe_set_handlers(&s->chr, NULL, NULL, net_vhost_user_event,
-- 
2.17.1