[Qemu-devel] [PATCH v2 22/23] vhost-user: wait until backend init is completed

[marcandre . lureau]

From: Marc-André Lureau <marcandre.lur...@redhat.com>

The chardev waits for an initial connection before starting qemu,
vhost-user wants the backend negotiation to be completed. vhost-user is
started in the net_vhost_user_event callback, which is synchronously
called after the socket is connected.

Signed-off-by: Marc-André Lureau <marcandre.lur...@redhat.com>
---
 net/vhost-user.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/net/vhost-user.c b/net/vhost-user.c
index 95ed2d2..4badd9e 100644
--- a/net/vhost-user.c
+++ b/net/vhost-user.c
@@ -24,6 +24,7 @@ typedef struct VhostUserState {
     VHostNetState *vhost_net;
     int watch;
     uint64_t acked_features;
+    bool started;
 } VhostUserState;
 
 typedef struct VhostUserChardevProps {
@@ -211,6 +212,7 @@ static void net_vhost_user_event(void *opaque, int event)
             return;
         }
         qmp_set_link(name, true, &err);
+        s->started = true;
         break;
     case CHR_EVENT_CLOSED:
         qmp_set_link(name, false, &err);
@@ -248,7 +250,15 @@ static int net_vhost_user_init(NetClientState *peer, const 
char *device,
         s->chr = chr;
     }
 
-    qemu_chr_add_handlers(chr, NULL, NULL, net_vhost_user_event, nc[0].name);
+    do {
+        Error *err = NULL;
+        if (qemu_chr_wait_connected(chr, &err) < 0) {
+            error_report_err(err);
+            return -1;
+        }
+        qemu_chr_add_handlers(chr, NULL, NULL,
+                              net_vhost_user_event, nc[0].name);
+    } while (!s->started);
 
     assert(s->vhost_net != NULL);
 
-- 
2.9.0