[Qemu-devel] [RFC PATCH v3 3/5] net: resolve race of tap backend and its peer

[Liu Ping Fan]

When vhost net enabled, we should be sure that the user space
fd handler is not in flight

Signed-off-by: Liu Ping Fan <address@hidden>
---
 net/tap.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/net/tap.c b/net/tap.c
index e19bb07..a3947eb 100644
--- a/net/tap.c
+++ b/net/tap.c
@@ -324,6 +324,11 @@ static void tap_poll(NetClientState *nc, bool enable)
     /* fixme, when tap backend on another thread, the disable should be sync */
     tap_read_poll(s, enable);
     tap_write_poll(s, enable);
+
+    if (!enable) {
+        /* need sync so vhost can take over polling */
+        g_source_remove_poll(&nc->nsrc->source, &nc->nsrc->gfd);
+    }
 }
 
 int tap_get_fd(NetClientState *nc)
-- 
1.7.4.4